The Tor Browser: layout/base/nsPresShell.cpp@6474c204b198 (annotated)

layout/base/nsPresShell.cpp@6474c204b198 (annotated)

layout/base/nsPresShell.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
  * vim: set ts=2 sw=2 et tw=78:
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  *
  * This Original Code has been modified by IBM Corporation.
  * Modifications made by IBM described herein are
  * Copyright (c) International Business Machines
  * Corporation, 2000
  *
  * Modifications to Mozilla code or documentation
  * identified per MPL Section 3.3
  *
  * Date         Modified by     Description of modification
  * 05/03/2000   IBM Corp.       Observer events for reflow states
  */
 /* a presentation of a document, part 2 */
 #ifdef MOZ_LOGGING
 #define FORCE_PR_LOG /* Allow logging in the release build */
 #endif
 #include "prlog.h"
 #include "mozilla/ArrayUtils.h"
 #include "mozilla/EventDispatcher.h"
 #include "mozilla/EventStateManager.h"
 #include "mozilla/EventStates.h"
 #include "mozilla/IMEStateManager.h"
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/dom/TabChild.h"
 #include "mozilla/Likely.h"
 #include "mozilla/MouseEvents.h"
 #include "mozilla/TextEvents.h"
 #include "mozilla/TouchEvents.h"
 #include <algorithm>
 #ifdef XP_WIN
 #include "winuser.h"
 #endif
 #include "nsPresShell.h"
 #include "nsPresContext.h"
 #include "nsIContent.h"
 #include "mozilla/dom/Element.h"
 #include "mozilla/dom/Event.h" // for Event::GetEventPopupControlState()
 #include "mozilla/dom/ShadowRoot.h"
 #include "mozilla/dom/PointerEvent.h"
 #include "nsIDocument.h"
 #include "nsCSSStyleSheet.h"
 #include "nsAnimationManager.h"
 #include "nsNameSpaceManager.h"  // for Pref-related rule management (bugs 22963,20760,31816)
 #include "nsFrame.h"
 #include "FrameLayerBuilder.h"
 #include "nsViewManager.h"
 #include "nsView.h"
 #include "nsCRTGlue.h"
 #include "prprf.h"
 #include "prinrval.h"
 #include "nsTArray.h"
 #include "nsCOMArray.h"
 #include "nsContainerFrame.h"
 #include "nsISelection.h"
 #include "mozilla/dom/Selection.h"
 #include "nsGkAtoms.h"
 #include "nsIDOMRange.h"
 #include "nsIDOMDocument.h"
 #include "nsIDOMNode.h"
 #include "nsIDOMNodeList.h"
 #include "nsIDOMElement.h"
 #include "nsRange.h"
 #include "nsCOMPtr.h"
 #include "nsAutoPtr.h"
 #include "nsReadableUtils.h"
 #include "nsIPageSequenceFrame.h"
 #include "nsCaret.h"
 #include "nsIDOMHTMLDocument.h"
 #include "nsFrameManager.h"
 #include "nsXPCOM.h"
 #include "nsILayoutHistoryState.h"
 #include "nsILineIterator.h" // for ScrollContentIntoView
 #include "pldhash.h"
 #include "mozilla/dom/Touch.h"
 #include "mozilla/dom/PointerEventBinding.h"
 #include "nsIObserverService.h"
 #include "nsDocShell.h"        // for reflow observation
 #include "nsIBaseWindow.h"
 #include "nsError.h"
 #include "nsLayoutUtils.h"
 #include "nsViewportInfo.h"
 #include "nsCSSRendering.h"
   // for |#ifdef DEBUG| code
 #include "prenv.h"
 #include "nsDisplayList.h"
 #include "nsRegion.h"
 #include "nsRenderingContext.h"
 #include "nsAutoLayoutPhase.h"
 #ifdef MOZ_REFLOW_PERF
 #include "nsFontMetrics.h"
 #endif
 #include "PositionedEventTargeting.h"
 #include "nsIReflowCallback.h"
 #include "nsPIDOMWindow.h"
 #include "nsFocusManager.h"
 #include "nsIObjectFrame.h"
 #include "nsIObjectLoadingContent.h"
 #include "nsNetUtil.h"
 #include "nsThreadUtils.h"
 #include "nsStyleSheetService.h"
 #include "gfxImageSurface.h"
 #include "gfxContext.h"
 #include "nsSMILAnimationController.h"
 #include "SVGContentUtils.h"
 #include "nsSVGEffects.h"
 #include "SVGFragmentIdentifier.h"
 #include "nsArenaMemoryStats.h"
 #include "nsPerformance.h"
 #include "nsRefreshDriver.h"
 #include "nsDOMNavigationTiming.h"
 // Drag & Drop, Clipboard
 #include "nsIDocShellTreeItem.h"
 #include "nsIURI.h"
 #include "nsIScrollableFrame.h"
 #include "nsITimer.h"
 #ifdef ACCESSIBILITY
 #include "nsAccessibilityService.h"
 #include "mozilla/a11y/DocAccessible.h"
 #ifdef DEBUG
 #include "mozilla/a11y/Logging.h"
 #endif
 #endif
 // For style data reconstruction
 #include "nsStyleChangeList.h"
 #include "nsCSSFrameConstructor.h"
 #ifdef MOZ_XUL
 #include "nsMenuFrame.h"
 #include "nsTreeBodyFrame.h"
 #include "nsIBoxObject.h"
 #include "nsITreeBoxObject.h"
 #include "nsMenuPopupFrame.h"
 #include "nsITreeColumns.h"
 #include "nsIDOMXULMultSelectCntrlEl.h"
 #include "nsIDOMXULSelectCntrlItemEl.h"
 #include "nsIDOMXULMenuListElement.h"
 #endif
 #include "GeckoProfiler.h"
 #include "gfxPlatform.h"
 #include "Layers.h"
 #include "LayerTreeInvalidation.h"
 #include "mozilla/css/ImageLoader.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/Telemetry.h"
 #include "nsCanvasFrame.h"
 #include "nsIImageLoadingContent.h"
 #include "nsIScreen.h"
 #include "nsIScreenManager.h"
 #include "nsPlaceholderFrame.h"
 #include "nsTransitionManager.h"
 #include "ChildIterator.h"
 #include "RestyleManager.h"
 #include "nsIDOMHTMLElement.h"
 #include "nsIDragSession.h"
 #include "nsIFrameInlines.h"
 #include "mozilla/gfx/2D.h"
 #ifdef ANDROID
 #include "nsIDocShellTreeOwner.h"
 #endif
 #ifdef MOZ_TASK_TRACER
 #include "GeckoTaskTracer.h"
 using namespace mozilla::tasktracer;
 #endif
 #define ANCHOR_SCROLL_FLAGS \
   (nsIPresShell::SCROLL_OVERFLOW_HIDDEN | nsIPresShell::SCROLL_NO_PARENT_FRAMES)
 using namespace mozilla;
 using namespace mozilla::css;
 using namespace mozilla::dom;
 using namespace mozilla::gfx;
 using namespace mozilla::layers;
 using namespace mozilla::gfx;
 CapturingContentInfo nsIPresShell::gCaptureInfo =
   { false /* mAllowed */, false /* mPointerLock */, false /* mRetargetToElement */,
     false /* mPreventDrag */, nullptr /* mContent */ };
 nsIContent* nsIPresShell::gKeyDownTarget;
 nsRefPtrHashtable<nsUint32HashKey, dom::Touch>* nsIPresShell::gCaptureTouchList;
 nsRefPtrHashtable<nsUint32HashKey, nsIContent>* nsIPresShell::gPointerCaptureList;
 nsClassHashtable<nsUint32HashKey, nsIPresShell::PointerInfo>* nsIPresShell::gActivePointersIds;
 bool nsIPresShell::gPreventMouseEvents = false;
 // convert a color value to a string, in the CSS format #RRGGBB
 // *  - initially created for bugs 31816, 20760, 22963
 static void ColorToString(nscolor aColor, nsAutoString &aString);
 // RangePaintInfo is used to paint ranges to offscreen buffers
 struct RangePaintInfo {
   nsRefPtr<nsRange> mRange;
   nsDisplayListBuilder mBuilder;
   nsDisplayList mList;
   // offset of builder's reference frame to the root frame
   nsPoint mRootOffset;
   RangePaintInfo(nsRange* aRange, nsIFrame* aFrame)
     : mRange(aRange), mBuilder(aFrame, nsDisplayListBuilder::PAINTING, false)
   {
     MOZ_COUNT_CTOR(RangePaintInfo);
   }
   ~RangePaintInfo()
   {
     mList.DeleteAll();
     MOZ_COUNT_DTOR(RangePaintInfo);
   }
 };
 #undef NOISY
 // ----------------------------------------------------------------------
 #ifdef DEBUG
 // Set the environment variable GECKO_VERIFY_REFLOW_FLAGS to one or
 // more of the following flags (comma separated) for handy debug
 // output.
 static uint32_t gVerifyReflowFlags;
 struct VerifyReflowFlags {
   const char*    name;
   uint32_t bit;
 };
 static const VerifyReflowFlags gFlags[] = {
   { "verify",                VERIFY_REFLOW_ON },
   { "reflow",                VERIFY_REFLOW_NOISY },
   { "all",                   VERIFY_REFLOW_ALL },
   { "list-commands",         VERIFY_REFLOW_DUMP_COMMANDS },
   { "noisy-commands",        VERIFY_REFLOW_NOISY_RC },
   { "really-noisy-commands", VERIFY_REFLOW_REALLY_NOISY_RC },
   { "resize",                VERIFY_REFLOW_DURING_RESIZE_REFLOW },
 };
 #define NUM_VERIFY_REFLOW_FLAGS (sizeof(gFlags) / sizeof(gFlags[0]))
 static void
 ShowVerifyReflowFlags()
 {
   printf("Here are the available GECKO_VERIFY_REFLOW_FLAGS:\n");
   const VerifyReflowFlags* flag = gFlags;
   const VerifyReflowFlags* limit = gFlags + NUM_VERIFY_REFLOW_FLAGS;
   while (flag < limit) {
     printf("  %s\n", flag->name);
     ++flag;
   }
   printf("Note: GECKO_VERIFY_REFLOW_FLAGS is a comma separated list of flag\n");
   printf("names (no whitespace)\n");
 }
 #endif
 //========================================================================
 //========================================================================
 //========================================================================
 #ifdef MOZ_REFLOW_PERF
 class ReflowCountMgr;
 static const char kGrandTotalsStr[] = "Grand Totals";
 // Counting Class
 class ReflowCounter {
 public:
   ReflowCounter(ReflowCountMgr * aMgr = nullptr);
   ~ReflowCounter();
   void ClearTotals();
   void DisplayTotals(const char * aStr);
   void DisplayDiffTotals(const char * aStr);
   void DisplayHTMLTotals(const char * aStr);
   void Add()                { mTotal++;         }
   void Add(uint32_t aTotal) { mTotal += aTotal; }
   void CalcDiffInTotals();
   void SetTotalsCache();
   void SetMgr(ReflowCountMgr * aMgr) { mMgr = aMgr; }
   uint32_t GetTotal() { return mTotal; }
 protected:
   void DisplayTotals(uint32_t aTotal, const char * aTitle);
   void DisplayHTMLTotals(uint32_t aTotal, const char * aTitle);
   uint32_t mTotal;
   uint32_t mCacheTotal;
   ReflowCountMgr * mMgr; // weak reference (don't delete)
 };
 // Counting Class
 class IndiReflowCounter {
 public:
   IndiReflowCounter(ReflowCountMgr * aMgr = nullptr)
     : mFrame(nullptr),
       mCount(0),
       mMgr(aMgr),
       mCounter(aMgr),
       mHasBeenOutput(false)
     {}
   virtual ~IndiReflowCounter() {}
   nsAutoString mName;
   nsIFrame *   mFrame;   // weak reference (don't delete)
   int32_t      mCount;
   ReflowCountMgr * mMgr; // weak reference (don't delete)
   ReflowCounter mCounter;
   bool          mHasBeenOutput;
 };
 //--------------------
 // Manager Class
 //--------------------
 class ReflowCountMgr {
 public:
   ReflowCountMgr();
   virtual ~ReflowCountMgr();
   void ClearTotals();
   void ClearGrandTotals();
   void DisplayTotals(const char * aStr);
   void DisplayHTMLTotals(const char * aStr);
   void DisplayDiffsInTotals(const char * aStr);
   void Add(const char * aName, nsIFrame * aFrame);
   ReflowCounter * LookUp(const char * aName);
   void PaintCount(const char *aName, nsRenderingContext* aRenderingContext,
                   nsPresContext *aPresContext, nsIFrame *aFrame,
                   const nsPoint &aOffset, uint32_t aColor);
   FILE * GetOutFile() { return mFD; }
   PLHashTable * GetIndiFrameHT() { return mIndiFrameCounts; }
   void SetPresContext(nsPresContext * aPresContext) { mPresContext = aPresContext; } // weak reference
   void SetPresShell(nsIPresShell* aPresShell) { mPresShell= aPresShell; } // weak reference
   void SetDumpFrameCounts(bool aVal)         { mDumpFrameCounts = aVal; }
   void SetDumpFrameByFrameCounts(bool aVal)  { mDumpFrameByFrameCounts = aVal; }
   void SetPaintFrameCounts(bool aVal)        { mPaintFrameByFrameCounts = aVal; }
   bool IsPaintingFrameCounts() { return mPaintFrameByFrameCounts; }
 protected:
   void DisplayTotals(uint32_t aTotal, uint32_t * aDupArray, char * aTitle);
   void DisplayHTMLTotals(uint32_t aTotal, uint32_t * aDupArray, char * aTitle);
   static int RemoveItems(PLHashEntry *he, int i, void *arg);
   static int RemoveIndiItems(PLHashEntry *he, int i, void *arg);
   void CleanUp();
   // stdout Output Methods
   static int DoSingleTotal(PLHashEntry *he, int i, void *arg);
   static int DoSingleIndi(PLHashEntry *he, int i, void *arg);
   void DoGrandTotals();
   void DoIndiTotalsTree();
   // HTML Output Methods
   static int DoSingleHTMLTotal(PLHashEntry *he, int i, void *arg);
   void DoGrandHTMLTotals();
   // Zero Out the Totals
   static int DoClearTotals(PLHashEntry *he, int i, void *arg);
   // Displays the Diff Totals
   static int DoDisplayDiffTotals(PLHashEntry *he, int i, void *arg);
   PLHashTable * mCounts;
   PLHashTable * mIndiFrameCounts;
   FILE * mFD;
   bool mDumpFrameCounts;
   bool mDumpFrameByFrameCounts;
   bool mPaintFrameByFrameCounts;
   bool mCycledOnce;
   // Root Frame for Individual Tracking
   nsPresContext * mPresContext;
   nsIPresShell*    mPresShell;
   // ReflowCountMgr gReflowCountMgr;
 };
 #endif
 //========================================================================
 // comment out to hide caret
 #define SHOW_CARET
 // The upper bound on the amount of time to spend reflowing, in
 // microseconds.  When this bound is exceeded and reflow commands are
 // still queued up, a reflow event is posted.  The idea is for reflow
 // to not hog the processor beyond the time specifed in
 // gMaxRCProcessingTime.  This data member is initialized from the
 // layout.reflow.timeslice pref.
 #define NS_MAX_REFLOW_TIME    1000000
 static int32_t gMaxRCProcessingTime = -1;
 struct nsCallbackEventRequest
 {
   nsIReflowCallback* callback;
   nsCallbackEventRequest* next;
 };
 // ----------------------------------------------------------------------------
 #define ASSERT_REFLOW_SCHEDULED_STATE()                                       \
   NS_ASSERTION(mReflowScheduled ==                                            \
                  GetPresContext()->RefreshDriver()->                          \
                    IsLayoutFlushObserver(this), "Unexpected state")
 class nsAutoCauseReflowNotifier
 {
 public:
   nsAutoCauseReflowNotifier(PresShell* aShell)
     : mShell(aShell)
   {
     mShell->WillCauseReflow();
   }
   ~nsAutoCauseReflowNotifier()
   {
     // This check should not be needed. Currently the only place that seem
     // to need it is the code that deals with bug 337586.
     if (!mShell->mHaveShutDown) {
       mShell->DidCauseReflow();
     }
     else {
       nsContentUtils::RemoveScriptBlocker();
     }
   }
   PresShell* mShell;
 };
 class MOZ_STACK_CLASS nsPresShellEventCB : public EventDispatchingCallback
 {
 public:
   nsPresShellEventCB(PresShell* aPresShell) : mPresShell(aPresShell) {}
   virtual void HandleEvent(EventChainPostVisitor& aVisitor) MOZ_OVERRIDE
   {
     if (aVisitor.mPresContext && aVisitor.mEvent->eventStructType != NS_EVENT) {
       if (aVisitor.mEvent->message == NS_MOUSE_BUTTON_DOWN ||
           aVisitor.mEvent->message == NS_MOUSE_BUTTON_UP) {
         // Mouse-up and mouse-down events call nsFrame::HandlePress/Release
         // which call GetContentOffsetsFromPoint which requires up-to-date layout.
         // Bring layout up-to-date now so that GetCurrentEventFrame() below
         // will return a real frame and we don't have to worry about
         // destroying it by flushing later.
         mPresShell->FlushPendingNotifications(Flush_Layout);
       } else if (aVisitor.mEvent->message == NS_WHEEL_WHEEL &&
                  aVisitor.mEventStatus != nsEventStatus_eConsumeNoDefault) {
         nsIFrame* frame = mPresShell->GetCurrentEventFrame();
         if (frame) {
           // chrome (including addons) should be able to know if content
           // handles both D3E "wheel" event and legacy mouse scroll events.
           // We should dispatch legacy mouse events before dispatching the
           // "wheel" event into system group.
           nsRefPtr<EventStateManager> esm =
             aVisitor.mPresContext->EventStateManager();
           esm->DispatchLegacyMouseScrollEvents(frame,
                                                aVisitor.mEvent->AsWheelEvent(),
                                                &aVisitor.mEventStatus);
         }
       }
       nsIFrame* frame = mPresShell->GetCurrentEventFrame();
       if (!frame &&
           (aVisitor.mEvent->message == NS_MOUSE_BUTTON_UP ||
            aVisitor.mEvent->message == NS_TOUCH_END)) {
         // Redirect BUTTON_UP and TOUCH_END events to the root frame to ensure
         // that capturing is released.
         frame = mPresShell->GetRootFrame();
       }
       if (frame) {
         frame->HandleEvent(aVisitor.mPresContext,
                            aVisitor.mEvent->AsGUIEvent(),
                            &aVisitor.mEventStatus);
       }
     }
   }
   nsRefPtr<PresShell> mPresShell;
 };
 class nsBeforeFirstPaintDispatcher : public nsRunnable
 {
 public:
   nsBeforeFirstPaintDispatcher(nsIDocument* aDocument)
   : mDocument(aDocument) {}
   // Fires the "before-first-paint" event so that interested parties (right now, the
   // mobile browser) are aware of it.
   NS_IMETHOD Run() MOZ_OVERRIDE
   {
     nsCOMPtr<nsIObserverService> observerService =
       mozilla::services::GetObserverService();
     if (observerService) {
       observerService->NotifyObservers(mDocument, "before-first-paint",
                                        nullptr);
     }
     return NS_OK;
   }
 private:
   nsCOMPtr<nsIDocument> mDocument;
 };
 bool PresShell::sDisableNonTestMouseEvents = false;
 #ifdef PR_LOGGING
 PRLogModuleInfo* PresShell::gLog;
 #endif
 #ifdef DEBUG
 static void
 VerifyStyleTree(nsPresContext* aPresContext, nsFrameManager* aFrameManager)
 {
   if (nsFrame::GetVerifyStyleTreeEnable()) {
     nsIFrame* rootFrame = aFrameManager->GetRootFrame();
     aPresContext->RestyleManager()->DebugVerifyStyleTree(rootFrame);
   }
 }
 #define VERIFY_STYLE_TREE ::VerifyStyleTree(mPresContext, mFrameConstructor)
 #else
 #define VERIFY_STYLE_TREE
 #endif
 static bool gVerifyReflowEnabled;
 bool
 nsIPresShell::GetVerifyReflowEnable()
 {
 #ifdef DEBUG
   static bool firstTime = true;
   if (firstTime) {
     firstTime = false;
     char* flags = PR_GetEnv("GECKO_VERIFY_REFLOW_FLAGS");
     if (flags) {
       bool error = false;
       for (;;) {
         char* comma = PL_strchr(flags, ',');
         if (comma)
           *comma = '\0';
         bool found = false;
         const VerifyReflowFlags* flag = gFlags;
         const VerifyReflowFlags* limit = gFlags + NUM_VERIFY_REFLOW_FLAGS;
         while (flag < limit) {
           if (PL_strcasecmp(flag->name, flags) == 0) {
             gVerifyReflowFlags |= flag->bit;
             found = true;
             break;
           }
           ++flag;
         }
         if (! found)
           error = true;
         if (! comma)
           break;
         *comma = ',';
         flags = comma + 1;
       }
       if (error)
         ShowVerifyReflowFlags();
     }
     if (VERIFY_REFLOW_ON & gVerifyReflowFlags) {
       gVerifyReflowEnabled = true;
       printf("Note: verifyreflow is enabled");
       if (VERIFY_REFLOW_NOISY & gVerifyReflowFlags) {
         printf(" (noisy)");
       }
       if (VERIFY_REFLOW_ALL & gVerifyReflowFlags) {
         printf(" (all)");
       }
       if (VERIFY_REFLOW_DUMP_COMMANDS & gVerifyReflowFlags) {
         printf(" (show reflow commands)");
       }
       if (VERIFY_REFLOW_NOISY_RC & gVerifyReflowFlags) {
         printf(" (noisy reflow commands)");
         if (VERIFY_REFLOW_REALLY_NOISY_RC & gVerifyReflowFlags) {
           printf(" (REALLY noisy reflow commands)");
         }
       }
       printf("\n");
     }
   }
 #endif
   return gVerifyReflowEnabled;
 }
 void
 PresShell::AddInvalidateHiddenPresShellObserver(nsRefreshDriver *aDriver)
 {
   if (!mHiddenInvalidationObserverRefreshDriver && !mIsDestroying && !mHaveShutDown) {
     aDriver->AddPresShellToInvalidateIfHidden(this);
     mHiddenInvalidationObserverRefreshDriver = aDriver;
   }
 }
 void
 nsIPresShell::InvalidatePresShellIfHidden()
 {
   if (!IsVisible() && mPresContext) {
     mPresContext->NotifyInvalidation(0);
   }
   mHiddenInvalidationObserverRefreshDriver = nullptr;
 }
 void
 nsIPresShell::CancelInvalidatePresShellIfHidden()
 {
   if (mHiddenInvalidationObserverRefreshDriver) {
     mHiddenInvalidationObserverRefreshDriver->RemovePresShellToInvalidateIfHidden(this);
     mHiddenInvalidationObserverRefreshDriver = nullptr;
   }
 }
 void
 nsIPresShell::SetVerifyReflowEnable(bool aEnabled)
 {
   gVerifyReflowEnabled = aEnabled;
 }
 /* virtual */ void
 nsIPresShell::AddWeakFrameExternal(nsWeakFrame* aWeakFrame)
 {
   AddWeakFrameInternal(aWeakFrame);
 }
 void
 nsIPresShell::AddWeakFrameInternal(nsWeakFrame* aWeakFrame)
 {
   if (aWeakFrame->GetFrame()) {
     aWeakFrame->GetFrame()->AddStateBits(NS_FRAME_EXTERNAL_REFERENCE);
   }
   aWeakFrame->SetPreviousWeakFrame(mWeakFrames);
   mWeakFrames = aWeakFrame;
 }
 /* virtual */ void
 nsIPresShell::RemoveWeakFrameExternal(nsWeakFrame* aWeakFrame)
 {
   RemoveWeakFrameInternal(aWeakFrame);
 }
 void
 nsIPresShell::RemoveWeakFrameInternal(nsWeakFrame* aWeakFrame)
 {
   if (mWeakFrames == aWeakFrame) {
     mWeakFrames = aWeakFrame->GetPreviousWeakFrame();
     return;
   }
   nsWeakFrame* nextWeak = mWeakFrames;
   while (nextWeak && nextWeak->GetPreviousWeakFrame() != aWeakFrame) {
     nextWeak = nextWeak->GetPreviousWeakFrame();
   }
   if (nextWeak) {
     nextWeak->SetPreviousWeakFrame(aWeakFrame->GetPreviousWeakFrame());
   }
 }
 already_AddRefed<nsFrameSelection>
 nsIPresShell::FrameSelection()
 {
   nsRefPtr<nsFrameSelection> ret = mSelection;
   return ret.forget();
 }
 //----------------------------------------------------------------------
 static bool sSynthMouseMove = true;
 static uint32_t sNextPresShellId;
 static bool sPointerEventEnabled = true;
 PresShell::PresShell()
   : mMouseLocation(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE)
 {
   mSelection = nullptr;
 #ifdef MOZ_REFLOW_PERF
   mReflowCountMgr = new ReflowCountMgr();
   mReflowCountMgr->SetPresContext(mPresContext);
   mReflowCountMgr->SetPresShell(this);
 #endif
 #ifdef PR_LOGGING
   mLoadBegin = TimeStamp::Now();
   if (!gLog) {
     gLog = PR_NewLogModule("PresShell");
   }
 #endif
   mSelectionFlags = nsISelectionDisplay::DISPLAY_TEXT | nsISelectionDisplay::DISPLAY_IMAGES;
   mIsThemeSupportDisabled = false;
   mIsActive = true;
   // FIXME/bug 735029: find a better solution to this problem
 #ifdef MOZ_ANDROID_OMTC
   // The java pan/zoom code uses this to mean approximately "request a
   // reset of pan/zoom state" which doesn't necessarily correspond
   // with the first paint of content.
   mIsFirstPaint = false;
 #else
   mIsFirstPaint = true;
 #endif
   mPresShellId = sNextPresShellId++;
   mFrozen = false;
 #ifdef DEBUG
   mPresArenaAllocCount = 0;
 #endif
   mRenderFlags = 0;
   mXResolution = 1.0;
   mYResolution = 1.0;
   mViewportOverridden = false;
   mScrollPositionClampingScrollPortSizeSet = false;
   mMaxLineBoxWidth = 0;
   static bool addedSynthMouseMove = false;
   if (!addedSynthMouseMove) {
     Preferences::AddBoolVarCache(&sSynthMouseMove,
                                  "layout.reflow.synthMouseMove", true);
     addedSynthMouseMove = true;
   }
   static bool addedPointerEventEnabled = false;
   if (!addedPointerEventEnabled) {
     Preferences::AddBoolVarCache(&sPointerEventEnabled,
                                  "dom.w3c_pointer_events.enabled", true);
     addedPointerEventEnabled = true;
   }
   mPaintingIsFrozen = false;
 }
 NS_IMPL_ISUPPORTS(PresShell, nsIPresShell, nsIDocumentObserver,
                   nsISelectionController,
                   nsISelectionDisplay, nsIObserver, nsISupportsWeakReference,
                   nsIMutationObserver)
 PresShell::~PresShell()
 {
   if (!mHaveShutDown) {
     NS_NOTREACHED("Someone did not call nsIPresShell::destroy");
     Destroy();
   }
   NS_ASSERTION(mCurrentEventContentStack.Count() == 0,
                "Huh, event content left on the stack in pres shell dtor!");
   NS_ASSERTION(mFirstCallbackEventRequest == nullptr &&
                mLastCallbackEventRequest == nullptr,
                "post-reflow queues not empty.  This means we're leaking");
   // Verify that if painting was frozen, but we're being removed from the tree,
   // that we now re-enable painting on our refresh driver, since it may need to
   // be re-used by another presentation.
   if (mPaintingIsFrozen) {
     mPresContext->RefreshDriver()->Thaw();
   }
 #ifdef DEBUG
   MOZ_ASSERT(mPresArenaAllocCount == 0,
              "Some pres arena objects were not freed");
 #endif
   delete mStyleSet;
   delete mFrameConstructor;
   mCurrentEventContent = nullptr;
   NS_IF_RELEASE(mPresContext);
   NS_IF_RELEASE(mDocument);
   NS_IF_RELEASE(mSelection);
 }
 /**
  * Initialize the presentation shell. Create view manager and style
  * manager.
  * Note this can't be merged into our constructor because caret initialization
  * calls AddRef() on us.
  */
 void
 PresShell::Init(nsIDocument* aDocument,
                 nsPresContext* aPresContext,
                 nsViewManager* aViewManager,
                 nsStyleSet* aStyleSet,
                 nsCompatibility aCompatMode)
 {
   NS_PRECONDITION(aDocument, "null ptr");
   NS_PRECONDITION(aPresContext, "null ptr");
   NS_PRECONDITION(aViewManager, "null ptr");
   NS_PRECONDITION(!mDocument, "already initialized");
   if (!aDocument || !aPresContext || !aViewManager || mDocument) {
     return;
   }
   mDocument = aDocument;
   NS_ADDREF(mDocument);
   mViewManager = aViewManager;
   // Create our frame constructor.
   mFrameConstructor = new nsCSSFrameConstructor(mDocument, this, aStyleSet);
   mFrameManager = mFrameConstructor;
   // The document viewer owns both view manager and pres shell.
   mViewManager->SetPresShell(this);
   // Bind the context to the presentation shell.
   mPresContext = aPresContext;
   NS_ADDREF(mPresContext);
   aPresContext->SetShell(this);
   // Now we can initialize the style set.
   aStyleSet->Init(aPresContext);
   mStyleSet = aStyleSet;
   // Notify our prescontext that it now has a compatibility mode.  Note that
   // this MUST happen after we set up our style set but before we create any
   // frames.
   mPresContext->CompatibilityModeChanged();
   // setup the preference style rules (no forced reflow), and do it
   // before creating any frames.
   SetPreferenceStyleRules(false);
   NS_ADDREF(mSelection = new nsFrameSelection());
   mSelection->Init(this, nullptr);
   // Important: this has to happen after the selection has been set up
 #ifdef SHOW_CARET
   // make the caret
   mCaret = new nsCaret();
   mCaret->Init(this);
   mOriginalCaret = mCaret;
   //SetCaretEnabled(true);       // make it show in browser windows
 #endif
   //set up selection to be displayed in document
   // Don't enable selection for print media
   nsPresContext::nsPresContextType type = aPresContext->Type();
   if (type != nsPresContext::eContext_PrintPreview &&
       type != nsPresContext::eContext_Print)
     SetDisplaySelection(nsISelectionController::SELECTION_DISABLED);
   if (gMaxRCProcessingTime == -1) {
     gMaxRCProcessingTime =
       Preferences::GetInt("layout.reflow.timeslice", NS_MAX_REFLOW_TIME);
   }
   {
     nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
     if (os) {
       os->AddObserver(this, "agent-sheet-added", false);
       os->AddObserver(this, "user-sheet-added", false);
       os->AddObserver(this, "author-sheet-added", false);
       os->AddObserver(this, "agent-sheet-removed", false);
       os->AddObserver(this, "user-sheet-removed", false);
       os->AddObserver(this, "author-sheet-removed", false);
 #ifdef MOZ_XUL
       os->AddObserver(this, "chrome-flush-skin-caches", false);
 #endif
     }
   }
 #ifdef MOZ_REFLOW_PERF
     if (mReflowCountMgr) {
       bool paintFrameCounts =
         Preferences::GetBool("layout.reflow.showframecounts");
       bool dumpFrameCounts =
         Preferences::GetBool("layout.reflow.dumpframecounts");
       bool dumpFrameByFrameCounts =
         Preferences::GetBool("layout.reflow.dumpframebyframecounts");
       mReflowCountMgr->SetDumpFrameCounts(dumpFrameCounts);
       mReflowCountMgr->SetDumpFrameByFrameCounts(dumpFrameByFrameCounts);
       mReflowCountMgr->SetPaintFrameCounts(paintFrameCounts);
     }
 #endif
   if (mDocument->HasAnimationController()) {
     nsSMILAnimationController* animCtrl = mDocument->GetAnimationController();
     animCtrl->NotifyRefreshDriverCreated(GetPresContext()->RefreshDriver());
   }
   // Get our activeness from the docShell.
   QueryIsActive();
   // Setup our font inflation preferences.
   SetupFontInflation();
 }
 #ifdef PR_LOGGING
 enum TextPerfLogType {
   eLog_reflow,
   eLog_loaddone,
   eLog_totals
 };
 static void
 LogTextPerfStats(gfxTextPerfMetrics* aTextPerf,
                  PresShell* aPresShell,
                  const gfxTextPerfMetrics::TextCounts& aCounts,
                  float aTime, TextPerfLogType aLogType, const char* aURL)
 {
   char prefix[256];
   switch (aLogType) {
     case eLog_reflow:
       sprintf(prefix, "(textperf-reflow) %p time-ms: %7.0f", aPresShell, aTime);
       break;
     case eLog_loaddone:
       sprintf(prefix, "(textperf-loaddone) %p time-ms: %7.0f", aPresShell, aTime);
       break;
     default:
       MOZ_ASSERT(aLogType == eLog_totals, "unknown textperf log type");
       sprintf(prefix, "(textperf-totals) %p", aPresShell);
   }
   PRLogModuleInfo* tpLog = gfxPlatform::GetLog(eGfxLog_textperf);
   // ignore XUL contexts unless at debug level
   PRLogModuleLevel logLevel = PR_LOG_WARNING;
   if (aCounts.numContentTextRuns == 0) {
     logLevel = PR_LOG_DEBUG;
   }
   double hitRatio = 0.0;
   uint32_t lookups = aCounts.wordCacheHit + aCounts.wordCacheMiss;
   if (lookups) {
     hitRatio = double(aCounts.wordCacheHit) / double(lookups);
   }
   if (aLogType == eLog_loaddone) {
     PR_LOG(tpLog, logLevel,
            ("%s reflow: %d chars: %d "
             "[%s] "
             "content-textruns: %d chrome-textruns: %d "
             "max-textrun-len: %d "
             "word-cache-lookups: %d word-cache-hit-ratio: %4.3f "
             "word-cache-space: %d word-cache-long: %d "
             "pref-fallbacks: %d system-fallbacks: %d "
             "textruns-const: %d textruns-destr: %d "
             "cumulative-textruns-destr: %d\n",
             prefix, aTextPerf->reflowCount, aCounts.numChars,
             (aURL ? aURL : ""),
             aCounts.numContentTextRuns, aCounts.numChromeTextRuns,
             aCounts.maxTextRunLen,
             lookups, hitRatio,
             aCounts.wordCacheSpaceRules, aCounts.wordCacheLong,
             aCounts.fallbackPrefs, aCounts.fallbackSystem,
             aCounts.textrunConst, aCounts.textrunDestr,
             aTextPerf->cumulative.textrunDestr));
   } else {
     PR_LOG(tpLog, logLevel,
            ("%s reflow: %d chars: %d "
             "content-textruns: %d chrome-textruns: %d "
             "max-textrun-len: %d "
             "word-cache-lookups: %d word-cache-hit-ratio: %4.3f "
             "word-cache-space: %d word-cache-long: %d "
             "pref-fallbacks: %d system-fallbacks: %d "
             "textruns-const: %d textruns-destr: %d "
             "cumulative-textruns-destr: %d\n",
             prefix, aTextPerf->reflowCount, aCounts.numChars,
             aCounts.numContentTextRuns, aCounts.numChromeTextRuns,
             aCounts.maxTextRunLen,
             lookups, hitRatio,
             aCounts.wordCacheSpaceRules, aCounts.wordCacheLong,
             aCounts.fallbackPrefs, aCounts.fallbackSystem,
             aCounts.textrunConst, aCounts.textrunDestr,
             aTextPerf->cumulative.textrunDestr));
   }
 }
 #endif
 void
 PresShell::Destroy()
 {
   NS_ASSERTION(!nsContentUtils::IsSafeToRunScript(),
     "destroy called on presshell while scripts not blocked");
   // dump out cumulative text perf metrics
 #ifdef PR_LOGGING
   gfxTextPerfMetrics* tp;
   if (mPresContext && (tp = mPresContext->GetTextPerfMetrics())) {
     tp->Accumulate();
     if (tp->cumulative.numChars > 0) {
       LogTextPerfStats(tp, this, tp->cumulative, 0.0, eLog_totals, nullptr);
     }
   }
 #endif
 #ifdef MOZ_REFLOW_PERF
   DumpReflows();
   if (mReflowCountMgr) {
     delete mReflowCountMgr;
     mReflowCountMgr = nullptr;
   }
 #endif
   if (mHaveShutDown)
     return;
 #ifdef ACCESSIBILITY
   if (mDocAccessible) {
 #ifdef DEBUG
     if (a11y::logging::IsEnabled(a11y::logging::eDocDestroy))
       a11y::logging::DocDestroy("presshell destroyed", mDocument);
 #endif
     mDocAccessible->Shutdown();
     mDocAccessible = nullptr;
   }
 #endif // ACCESSIBILITY
   MaybeReleaseCapturingContent();
   if (gKeyDownTarget && gKeyDownTarget->OwnerDoc() == mDocument) {
     NS_RELEASE(gKeyDownTarget);
   }
   if (mContentToScrollTo) {
     mContentToScrollTo->DeleteProperty(nsGkAtoms::scrolling);
     mContentToScrollTo = nullptr;
   }
   if (mPresContext) {
     // We need to notify the destroying the nsPresContext to ESM for
     // suppressing to use from ESM.
     mPresContext->EventStateManager()->NotifyDestroyPresContext(mPresContext);
   }
   {
     nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
     if (os) {
       os->RemoveObserver(this, "agent-sheet-added");
       os->RemoveObserver(this, "user-sheet-added");
       os->RemoveObserver(this, "author-sheet-added");
       os->RemoveObserver(this, "agent-sheet-removed");
       os->RemoveObserver(this, "user-sheet-removed");
       os->RemoveObserver(this, "author-sheet-removed");
 #ifdef MOZ_XUL
       os->RemoveObserver(this, "chrome-flush-skin-caches");
 #endif
     }
   }
   // If our paint suppression timer is still active, kill it.
   if (mPaintSuppressionTimer) {
     mPaintSuppressionTimer->Cancel();
     mPaintSuppressionTimer = nullptr;
   }
   // Same for our reflow continuation timer
   if (mReflowContinueTimer) {
     mReflowContinueTimer->Cancel();
     mReflowContinueTimer = nullptr;
   }
   if (mDelayedPaintTimer) {
     mDelayedPaintTimer->Cancel();
     mDelayedPaintTimer = nullptr;
   }
   mSynthMouseMoveEvent.Revoke();
   mUpdateImageVisibilityEvent.Revoke();
   ClearVisibleImagesList();
   if (mCaret) {
     mCaret->Terminate();
     mCaret = nullptr;
   }
   if (mSelection) {
     mSelection->DisconnectFromPresShell();
   }
   // release our pref style sheet, if we have one still
   ClearPreferenceStyleRules();
   mIsDestroying = true;
   // We can't release all the event content in
   // mCurrentEventContentStack here since there might be code on the
   // stack that will release the event content too. Double release
   // bad!
   // The frames will be torn down, so remove them from the current
   // event frame stack (since they'd be dangling references if we'd
   // leave them in) and null out the mCurrentEventFrame pointer as
   // well.
   mCurrentEventFrame = nullptr;
   int32_t i, count = mCurrentEventFrameStack.Length();
   for (i = 0; i < count; i++) {
     mCurrentEventFrameStack[i] = nullptr;
   }
   mFramesToDirty.Clear();
   if (mViewManager) {
     // Clear the view manager's weak pointer back to |this| in case it
     // was leaked.
     mViewManager->SetPresShell(nullptr);
     mViewManager = nullptr;
   }
   mStyleSet->BeginShutdown(mPresContext);
   nsRefreshDriver* rd = GetPresContext()->RefreshDriver();
   // This shell must be removed from the document before the frame
   // hierarchy is torn down to avoid finding deleted frames through
   // this presshell while the frames are being torn down
   if (mDocument) {
     NS_ASSERTION(mDocument->GetShell() == this, "Wrong shell?");
     mDocument->DeleteShell();
     if (mDocument->HasAnimationController()) {
       mDocument->GetAnimationController()->NotifyRefreshDriverDestroying(rd);
     }
   }
   // Revoke any pending events.  We need to do this and cancel pending reflows
   // before we destroy the frame manager, since apparently frame destruction
   // sometimes spins the event queue when plug-ins are involved(!).
   rd->RemoveLayoutFlushObserver(this);
   if (mHiddenInvalidationObserverRefreshDriver) {
     mHiddenInvalidationObserverRefreshDriver->RemovePresShellToInvalidateIfHidden(this);
   }
   if (rd->PresContext() == GetPresContext()) {
     rd->RevokeViewManagerFlush();
   }
   mResizeEvent.Revoke();
   if (mAsyncResizeTimerIsActive) {
     mAsyncResizeEventTimer->Cancel();
     mAsyncResizeTimerIsActive = false;
   }
   CancelAllPendingReflows();
   CancelPostedReflowCallbacks();
   // Destroy the frame manager. This will destroy the frame hierarchy
   mFrameConstructor->WillDestroyFrameTree();
   // Destroy all frame properties (whose destruction was suppressed
   // while destroying the frame tree, but which might contain more
   // frames within the properties.
   if (mPresContext) {
     // Clear out the prescontext's property table -- since our frame tree is
     // now dead, we shouldn't be looking up any more properties in that table.
     // We want to do this before we call SetShell() on the prescontext, so
     // property destructors can usefully call GetPresShell() on the
     // prescontext.
     mPresContext->PropertyTable()->DeleteAll();
   }
   NS_WARN_IF_FALSE(!mWeakFrames, "Weak frames alive after destroying FrameManager");
   while (mWeakFrames) {
     mWeakFrames->Clear(this);
   }
   // Let the style set do its cleanup.
   mStyleSet->Shutdown(mPresContext);
   if (mPresContext) {
     // We hold a reference to the pres context, and it holds a weak link back
     // to us. To avoid the pres context having a dangling reference, set its
     // pres shell to nullptr
     mPresContext->SetShell(nullptr);
     // Clear the link handler (weak reference) as well
     mPresContext->SetLinkHandler(nullptr);
   }
   mHaveShutDown = true;
   EvictTouches();
 }
 void
 PresShell::MakeZombie()
 {
   mIsZombie = true;
   CancelAllPendingReflows();
 }
 void
 nsIPresShell::SetAuthorStyleDisabled(bool aStyleDisabled)
 {
   if (aStyleDisabled != mStyleSet->GetAuthorStyleDisabled()) {
     mStyleSet->SetAuthorStyleDisabled(aStyleDisabled);
     ReconstructStyleData();
     nsCOMPtr<nsIObserverService> observerService =
       mozilla::services::GetObserverService();
     if (observerService) {
       observerService->NotifyObservers(mDocument,
                                        "author-style-disabled-changed",
                                        nullptr);
     }
   }
 }
 bool
 nsIPresShell::GetAuthorStyleDisabled() const
 {
   return mStyleSet->GetAuthorStyleDisabled();
 }
 nsresult
 PresShell::SetPreferenceStyleRules(bool aForceReflow)
 {
   if (!mDocument) {
     return NS_ERROR_NULL_POINTER;
   }
   nsPIDOMWindow *window = mDocument->GetWindow();
   // If the document doesn't have a window there's no need to notify
   // its presshell about changes to preferences since the document is
   // in a state where it doesn't matter any more (see
   // nsDocumentViewer::Close()).
   if (!window) {
     return NS_ERROR_NULL_POINTER;
   }
   NS_PRECONDITION(mPresContext, "presContext cannot be null");
   if (mPresContext) {
     // first, make sure this is not a chrome shell
     if (nsContentUtils::IsInChromeDocshell(mDocument)) {
       return NS_OK;
     }
 #ifdef DEBUG_attinasi
     printf("Setting Preference Style Rules:\n");
 #endif
     // if here, we need to create rules for the prefs
     // - this includes the background-color, the text-color,
     //   the link color, the visited link color and the link-underlining
     // first clear any exising rules
     nsresult result = ClearPreferenceStyleRules();
     // now the link rules (must come after the color rules, or links will not be correct color!)
     // XXX - when there is both an override and agent pref stylesheet this won't matter,
     //       as the color rules will be overrides and the links rules will be agent
     if (NS_SUCCEEDED(result)) {
       result = SetPrefLinkRules();
     }
     if (NS_SUCCEEDED(result)) {
       result = SetPrefFocusRules();
     }
     if (NS_SUCCEEDED(result)) {
       result = SetPrefNoScriptRule();
     }
     if (NS_SUCCEEDED(result)) {
       result = SetPrefNoFramesRule();
     }
 #ifdef DEBUG_attinasi
     printf( "Preference Style Rules set: error=%ld\n", (long)result);
 #endif
     // Note that this method never needs to force any calculation; the caller
     // will recalculate style if needed
     return result;
   }
   return NS_ERROR_NULL_POINTER;
 }
 nsresult PresShell::ClearPreferenceStyleRules(void)
 {
   nsresult result = NS_OK;
   if (mPrefStyleSheet) {
     NS_ASSERTION(mStyleSet, "null styleset entirely unexpected!");
     if (mStyleSet) {
       // remove the sheet from the styleset:
       // - note that we have to check for success by comparing the count before and after...
 #ifdef DEBUG
       int32_t numBefore = mStyleSet->SheetCount(nsStyleSet::eUserSheet);
       NS_ASSERTION(numBefore > 0, "no user stylesheets in styleset, but we have one!");
 #endif
       mStyleSet->RemoveStyleSheet(nsStyleSet::eUserSheet, mPrefStyleSheet);
 #ifdef DEBUG_attinasi
       NS_ASSERTION((numBefore - 1) == mStyleSet->GetNumberOfUserStyleSheets(),
                    "Pref stylesheet was not removed");
       printf("PrefStyleSheet removed\n");
 #endif
       // clear the sheet pointer: it is strictly historical now
       mPrefStyleSheet = nullptr;
     }
   }
   return result;
 }
 nsresult
 PresShell::CreatePreferenceStyleSheet()
 {
   NS_ASSERTION(!mPrefStyleSheet, "prefStyleSheet already exists");
   mPrefStyleSheet = new nsCSSStyleSheet(CORS_NONE);
   nsCOMPtr<nsIURI> uri;
   nsresult rv = NS_NewURI(getter_AddRefs(uri), "about:PreferenceStyleSheet", nullptr);
   if (NS_FAILED(rv)) {
     mPrefStyleSheet = nullptr;
     return rv;
   }
   NS_ASSERTION(uri, "null but no error");
   mPrefStyleSheet->SetURIs(uri, uri, uri);
   mPrefStyleSheet->SetComplete();
   uint32_t index;
   rv =
     mPrefStyleSheet->InsertRuleInternal(NS_LITERAL_STRING("@namespace svg url(http://www.w3.org/2000/svg);"),
 , &index);
   if (NS_FAILED(rv)) {
     mPrefStyleSheet = nullptr;
     return rv;
   }
   rv =
     mPrefStyleSheet->InsertRuleInternal(NS_LITERAL_STRING("@namespace url(http://www.w3.org/1999/xhtml);"),
 , &index);
   if (NS_FAILED(rv)) {
     mPrefStyleSheet = nullptr;
     return rv;
   }
   mStyleSet->AppendStyleSheet(nsStyleSet::eUserSheet, mPrefStyleSheet);
   return NS_OK;
 }
 // XXX We want these after the @namespace rules.  Does order matter
 // for these rules, or can we call StyleRule::StyleRuleCount()
 // and just "append"?
 static uint32_t sInsertPrefSheetRulesAt = 2;
 nsresult
 PresShell::SetPrefNoScriptRule()
 {
   nsresult rv = NS_OK;
   // also handle the case where print is done from print preview
   // see bug #342439 for more details
   nsIDocument* doc = mDocument;
   if (doc->IsStaticDocument()) {
     doc = doc->GetOriginalDocument();
   }
   bool scriptEnabled = doc->IsScriptEnabled();
   if (scriptEnabled) {
     if (!mPrefStyleSheet) {
       rv = CreatePreferenceStyleSheet();
       NS_ENSURE_SUCCESS(rv, rv);
     }
     uint32_t index = 0;
     mPrefStyleSheet->
       InsertRuleInternal(NS_LITERAL_STRING("noscript{display:none!important}"),
                          sInsertPrefSheetRulesAt, &index);
   }
   return rv;
 }
 nsresult PresShell::SetPrefNoFramesRule(void)
 {
   NS_ASSERTION(mPresContext,"null prescontext not allowed");
   if (!mPresContext) {
     return NS_ERROR_FAILURE;
   }
   nsresult rv = NS_OK;
   if (!mPrefStyleSheet) {
     rv = CreatePreferenceStyleSheet();
     NS_ENSURE_SUCCESS(rv, rv);
   }
   NS_ASSERTION(mPrefStyleSheet, "prefstylesheet should not be null");
   bool allowSubframes = true;
   nsCOMPtr<nsIDocShell> docShell(mPresContext->GetDocShell());
   if (docShell) {
     docShell->GetAllowSubframes(&allowSubframes);
   }
   if (!allowSubframes) {
     uint32_t index = 0;
     rv = mPrefStyleSheet->
       InsertRuleInternal(NS_LITERAL_STRING("noframes{display:block}"),
                          sInsertPrefSheetRulesAt, &index);
     NS_ENSURE_SUCCESS(rv, rv);
     rv = mPrefStyleSheet->
       InsertRuleInternal(NS_LITERAL_STRING("frame, frameset, iframe {display:none!important}"),
                          sInsertPrefSheetRulesAt, &index);
   }
   return rv;
 }
 nsresult PresShell::SetPrefLinkRules(void)
 {
   NS_ASSERTION(mPresContext,"null prescontext not allowed");
   if (!mPresContext) {
     return NS_ERROR_FAILURE;
   }
   nsresult rv = NS_OK;
   if (!mPrefStyleSheet) {
     rv = CreatePreferenceStyleSheet();
     NS_ENSURE_SUCCESS(rv, rv);
   }
   NS_ASSERTION(mPrefStyleSheet, "prefstylesheet should not be null");
   // support default link colors:
   //   this means the link colors need to be overridable,
   //   which they are if we put them in the agent stylesheet,
   //   though if using an override sheet this will cause authors grief still
   //   In the agent stylesheet, they are !important when we are ignoring document colors
   nscolor linkColor(mPresContext->DefaultLinkColor());
   nscolor activeColor(mPresContext->DefaultActiveLinkColor());
   nscolor visitedColor(mPresContext->DefaultVisitedLinkColor());
   NS_NAMED_LITERAL_STRING(ruleClose, "}");
   uint32_t index = 0;
   nsAutoString strColor;
   // insert a rule to color links: '*|*:link {color: #RRGGBB [!important];}'
   ColorToString(linkColor, strColor);
   rv = mPrefStyleSheet->
     InsertRuleInternal(NS_LITERAL_STRING("*|*:link{color:") +
                        strColor + ruleClose,
                        sInsertPrefSheetRulesAt, &index);
   NS_ENSURE_SUCCESS(rv, rv);
   // - visited links: '*|*:visited {color: #RRGGBB [!important];}'
   ColorToString(visitedColor, strColor);
   rv = mPrefStyleSheet->
     InsertRuleInternal(NS_LITERAL_STRING("*|*:visited{color:") +
                        strColor + ruleClose,
                        sInsertPrefSheetRulesAt, &index);
   NS_ENSURE_SUCCESS(rv, rv);
   // - active links: '*|*:-moz-any-link:active {color: #RRGGBB [!important];}'
   ColorToString(activeColor, strColor);
   rv = mPrefStyleSheet->
     InsertRuleInternal(NS_LITERAL_STRING("*|*:-moz-any-link:active{color:") +
                        strColor + ruleClose,
                        sInsertPrefSheetRulesAt, &index);
   NS_ENSURE_SUCCESS(rv, rv);
   bool underlineLinks =
     mPresContext->GetCachedBoolPref(kPresContext_UnderlineLinks);
   if (underlineLinks) {
     // create a rule to make underlining happen
     //  '*|*:-moz-any-link {text-decoration:[underline|none];}'
     // no need for important, we want these to be overridable
     // NOTE: these must go in the agent stylesheet or they cannot be
     //       overridden by authors
     rv = mPrefStyleSheet->
       InsertRuleInternal(NS_LITERAL_STRING("*|*:-moz-any-link:not(svg|a){text-decoration:underline}"),
                          sInsertPrefSheetRulesAt, &index);
   } else {
     rv = mPrefStyleSheet->
       InsertRuleInternal(NS_LITERAL_STRING("*|*:-moz-any-link{text-decoration:none}"),
                          sInsertPrefSheetRulesAt, &index);
   }
   return rv;
 }
 nsresult PresShell::SetPrefFocusRules(void)
 {
   NS_ASSERTION(mPresContext,"null prescontext not allowed");
   nsresult result = NS_OK;
   if (!mPresContext)
     result = NS_ERROR_FAILURE;
   if (NS_SUCCEEDED(result) && !mPrefStyleSheet)
     result = CreatePreferenceStyleSheet();
   if (NS_SUCCEEDED(result)) {
     NS_ASSERTION(mPrefStyleSheet, "prefstylesheet should not be null");
     if (mPresContext->GetUseFocusColors()) {
       nscolor focusBackground(mPresContext->FocusBackgroundColor());
       nscolor focusText(mPresContext->FocusTextColor());
       // insert a rule to make focus the preferred color
       uint32_t index = 0;
       nsAutoString strRule, strColor;
       ///////////////////////////////////////////////////////////////
       // - focus: '*:focus
       ColorToString(focusText,strColor);
       strRule.AppendLiteral("*:focus,*:focus>font {color: ");
       strRule.Append(strColor);
       strRule.AppendLiteral(" !important; background-color: ");
       ColorToString(focusBackground,strColor);
       strRule.Append(strColor);
       strRule.AppendLiteral(" !important; } ");
       // insert the rules
       result = mPrefStyleSheet->
         InsertRuleInternal(strRule, sInsertPrefSheetRulesAt, &index);
     }
     uint8_t focusRingWidth = mPresContext->FocusRingWidth();
     bool focusRingOnAnything = mPresContext->GetFocusRingOnAnything();
     uint8_t focusRingStyle = mPresContext->GetFocusRingStyle();
     if ((NS_SUCCEEDED(result) && focusRingWidth != 1 && focusRingWidth <= 4 ) || focusRingOnAnything) {
       uint32_t index = 0;
       nsAutoString strRule;
       if (!focusRingOnAnything)
         strRule.AppendLiteral("*|*:link:focus, *|*:visited");    // If we only want focus rings on the normal things like links
       strRule.AppendLiteral(":focus {outline: ");     // For example 3px dotted WindowText (maximum 4)
       strRule.AppendInt(focusRingWidth);
       if (focusRingStyle == 0) // solid
         strRule.AppendLiteral("px solid -moz-mac-focusring !important; -moz-outline-radius: 3px; outline-offset: 1px; } ");
       else // dotted
         strRule.AppendLiteral("px dotted WindowText !important; } ");
       // insert the rules
       result = mPrefStyleSheet->
         InsertRuleInternal(strRule, sInsertPrefSheetRulesAt, &index);
       NS_ENSURE_SUCCESS(result, result);
       if (focusRingWidth != 1) {
         // If the focus ring width is different from the default, fix buttons with rings
         strRule.AssignLiteral("button::-moz-focus-inner, input[type=\"reset\"]::-moz-focus-inner,");
         strRule.AppendLiteral("input[type=\"button\"]::-moz-focus-inner, ");
         strRule.AppendLiteral("input[type=\"submit\"]::-moz-focus-inner { padding: 1px 2px 1px 2px; border: ");
         strRule.AppendInt(focusRingWidth);
         if (focusRingStyle == 0) // solid
           strRule.AppendLiteral("px solid transparent !important; } ");
         else
           strRule.AppendLiteral("px dotted transparent !important; } ");
         result = mPrefStyleSheet->
           InsertRuleInternal(strRule, sInsertPrefSheetRulesAt, &index);
         NS_ENSURE_SUCCESS(result, result);
         strRule.AssignLiteral("button:focus::-moz-focus-inner, input[type=\"reset\"]:focus::-moz-focus-inner,");
         strRule.AppendLiteral("input[type=\"button\"]:focus::-moz-focus-inner, input[type=\"submit\"]:focus::-moz-focus-inner {");
         strRule.AppendLiteral("border-color: ButtonText !important; }");
         result = mPrefStyleSheet->
           InsertRuleInternal(strRule, sInsertPrefSheetRulesAt, &index);
       }
     }
   }
   return result;
 }
 void
 PresShell::AddUserSheet(nsISupports* aSheet)
 {
   // Make sure this does what nsDocumentViewer::CreateStyleSet does wrt
   // ordering. We want this new sheet to come after all the existing stylesheet
   // service sheets, but before other user sheets; see nsIStyleSheetService.idl
   // for the ordering.  Just remove and readd all the nsStyleSheetService
   // sheets.
   nsCOMPtr<nsIStyleSheetService> dummy =
     do_GetService(NS_STYLESHEETSERVICE_CONTRACTID);
   mStyleSet->BeginUpdate();
   nsStyleSheetService *sheetService = nsStyleSheetService::gInstance;
   nsCOMArray<nsIStyleSheet> & userSheets = *sheetService->UserStyleSheets();
   int32_t i;
   // Iterate forwards when removing so the searches for RemoveStyleSheet are as
   // short as possible.
   for (i = 0; i < userSheets.Count(); ++i) {
     mStyleSet->RemoveStyleSheet(nsStyleSet::eUserSheet, userSheets[i]);
   }
   // Now iterate backwards, so that the order of userSheets will be the same as
   // the order of sheets from it in the style set.
   for (i = userSheets.Count() - 1; i >= 0; --i) {
     mStyleSet->PrependStyleSheet(nsStyleSet::eUserSheet, userSheets[i]);
   }
   mStyleSet->EndUpdate();
   ReconstructStyleData();
 }
 void
 PresShell::AddAgentSheet(nsISupports* aSheet)
 {
   // Make sure this does what nsDocumentViewer::CreateStyleSet does
   // wrt ordering.
   nsCOMPtr<nsIStyleSheet> sheet = do_QueryInterface(aSheet);
   if (!sheet) {
     return;
   }
   mStyleSet->AppendStyleSheet(nsStyleSet::eAgentSheet, sheet);
   ReconstructStyleData();
 }
 void
 PresShell::AddAuthorSheet(nsISupports* aSheet)
 {
   nsCOMPtr<nsIStyleSheet> sheet = do_QueryInterface(aSheet);
   if (!sheet) {
     return;
   }
   // Document specific "additional" Author sheets should be stronger than the ones
   // added with the StyleSheetService.
   nsIStyleSheet* firstAuthorSheet = mDocument->FirstAdditionalAuthorSheet();
   if (firstAuthorSheet) {
     mStyleSet->InsertStyleSheetBefore(nsStyleSet::eDocSheet, sheet, firstAuthorSheet);
   } else {
     mStyleSet->AppendStyleSheet(nsStyleSet::eDocSheet, sheet);
   }
   ReconstructStyleData();
 }
 void
 PresShell::RemoveSheet(nsStyleSet::sheetType aType, nsISupports* aSheet)
 {
   nsCOMPtr<nsIStyleSheet> sheet = do_QueryInterface(aSheet);
   if (!sheet) {
     return;
   }
   mStyleSet->RemoveStyleSheet(aType, sheet);
   ReconstructStyleData();
 }
 NS_IMETHODIMP
 PresShell::SetDisplaySelection(int16_t aToggle)
 {
   mSelection->SetDisplaySelection(aToggle);
   return NS_OK;
 }
 NS_IMETHODIMP
 PresShell::GetDisplaySelection(int16_t *aToggle)
 {
   *aToggle = mSelection->GetDisplaySelection();
   return NS_OK;
 }
 NS_IMETHODIMP
 PresShell::GetSelection(SelectionType aType, nsISelection **aSelection)
 {
   if (!aSelection || !mSelection)
     return NS_ERROR_NULL_POINTER;
   *aSelection = mSelection->GetSelection(aType);
   if (!(*aSelection))
     return NS_ERROR_INVALID_ARG;
   NS_ADDREF(*aSelection);
   return NS_OK;
 }
 Selection*
 PresShell::GetCurrentSelection(SelectionType aType)
 {
   if (!mSelection)
     return nullptr;
   return mSelection->GetSelection(aType);
 }
 NS_IMETHODIMP
 PresShell::ScrollSelectionIntoView(SelectionType aType, SelectionRegion aRegion,
                                    int16_t aFlags)
 {
   if (!mSelection)
     return NS_ERROR_NULL_POINTER;
   return mSelection->ScrollSelectionIntoView(aType, aRegion, aFlags);
 }
 NS_IMETHODIMP
 PresShell::RepaintSelection(SelectionType aType)
 {
   if (!mSelection)
     return NS_ERROR_NULL_POINTER;
   return mSelection->RepaintSelection(aType);
 }
 // Make shell be a document observer
 void
 PresShell::BeginObservingDocument()
 {
   if (mDocument && !mIsDestroying) {
     mDocument->AddObserver(this);
     if (mIsDocumentGone) {
       NS_WARNING("Adding a presshell that was disconnected from the document "
                  "as a document observer?  Sounds wrong...");
       mIsDocumentGone = false;
     }
   }
 }
 // Make shell stop being a document observer
 void
 PresShell::EndObservingDocument()
 {
   // XXXbz do we need to tell the frame constructor that the document
   // is gone, perhaps?  Except for printing it's NOT gone, sometimes.
   mIsDocumentGone = true;
   if (mDocument) {
     mDocument->RemoveObserver(this);
   }
 }
 #ifdef DEBUG_kipp
 char* nsPresShell_ReflowStackPointerTop;
 #endif
 nsresult
 PresShell::Initialize(nscoord aWidth, nscoord aHeight)
 {
   if (mIsDestroying) {
     return NS_OK;
   }
   if (!mDocument) {
     // Nothing to do
     return NS_OK;
   }
   mozilla::TimeStamp timerStart = mozilla::TimeStamp::Now();
   NS_ASSERTION(!mDidInitialize, "Why are we being called?");
   nsCOMPtr<nsIPresShell> kungFuDeathGrip(this);
   mDidInitialize = true;
 #ifdef DEBUG
   if (VERIFY_REFLOW_NOISY_RC & gVerifyReflowFlags) {
     if (mDocument) {
       nsIURI *uri = mDocument->GetDocumentURI();
       if (uri) {
         nsAutoCString url;
         uri->GetSpec(url);
         printf("*** PresShell::Initialize (this=%p, url='%s')\n", (void*)this, url.get());
       }
     }
   }
 #endif
   if (mCaret)
     mCaret->EraseCaret();
   // XXX Do a full invalidate at the beginning so that invalidates along
   // the way don't have region accumulation issues?
   mPresContext->SetVisibleArea(nsRect(0, 0, aWidth, aHeight));
   // Get the root frame from the frame manager
   // XXXbz it would be nice to move this somewhere else... like frame manager
   // Init(), say.  But we need to make sure our views are all set up by the
   // time we do this!
   nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
   NS_ASSERTION(!rootFrame, "How did that happen, exactly?");
   if (!rootFrame) {
     nsAutoScriptBlocker scriptBlocker;
     mFrameConstructor->BeginUpdate();
     rootFrame = mFrameConstructor->ConstructRootFrame();
     mFrameConstructor->SetRootFrame(rootFrame);
     mFrameConstructor->EndUpdate();
   }
   NS_ENSURE_STATE(!mHaveShutDown);
   if (!rootFrame) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
   for (nsIFrame* f = rootFrame; f; f = nsLayoutUtils::GetCrossDocParentFrame(f)) {
     if (f->GetStateBits() & NS_FRAME_NO_COMPONENT_ALPHA) {
       f->InvalidateFrameSubtree();
       f->RemoveStateBits(NS_FRAME_NO_COMPONENT_ALPHA);
     }
   }
   Element *root = mDocument->GetRootElement();
   if (root) {
     {
       nsAutoCauseReflowNotifier reflowNotifier(this);
       mFrameConstructor->BeginUpdate();
       // Have the style sheet processor construct frame for the root
       // content object down
       mFrameConstructor->ContentInserted(nullptr, root, nullptr, false);
       VERIFY_STYLE_TREE;
       // Something in mFrameConstructor->ContentInserted may have caused
       // Destroy() to get called, bug 337586.
       NS_ENSURE_STATE(!mHaveShutDown);
       mFrameConstructor->EndUpdate();
     }
     // nsAutoScriptBlocker going out of scope may have killed us too
     NS_ENSURE_STATE(!mHaveShutDown);
     // Run the XBL binding constructors for any new frames we've constructed
     mDocument->BindingManager()->ProcessAttachedQueue();
     // Constructors may have killed us too
     NS_ENSURE_STATE(!mHaveShutDown);
     // Now flush out pending restyles before we actually reflow, in
     // case XBL constructors changed styles somewhere.
     {
       nsAutoScriptBlocker scriptBlocker;
       mPresContext->RestyleManager()->ProcessPendingRestyles();
     }
     // And that might have run _more_ XBL constructors
     NS_ENSURE_STATE(!mHaveShutDown);
   }
   NS_ASSERTION(rootFrame, "How did that happen?");
   // Note: when the frame was created above it had the NS_FRAME_IS_DIRTY bit
   // set, but XBL processing could have caused a reflow which clears it.
   if (MOZ_LIKELY(rootFrame->GetStateBits() & NS_FRAME_IS_DIRTY)) {
     // Unset the DIRTY bits so that FrameNeedsReflow() will work right.
     rootFrame->RemoveStateBits(NS_FRAME_IS_DIRTY |
                                NS_FRAME_HAS_DIRTY_CHILDREN);
     NS_ASSERTION(!mDirtyRoots.Contains(rootFrame),
                  "Why is the root in mDirtyRoots already?");
     FrameNeedsReflow(rootFrame, eResize, NS_FRAME_IS_DIRTY);
     NS_ASSERTION(mDirtyRoots.Contains(rootFrame),
                  "Should be in mDirtyRoots now");
     NS_ASSERTION(mReflowScheduled, "Why no reflow scheduled?");
   }
   // Restore our root scroll position now if we're getting here after EndLoad
   // got called, since this is our one chance to do it.  Note that we need not
   // have reflowed for this to work; when the scrollframe is finally reflowed
   // it'll pick up the position we store in it here.
   if (!mDocumentLoading) {
     RestoreRootScrollPosition();
   }
   // For printing, we just immediately unsuppress.
   if (!mPresContext->IsPaginated()) {
     // Kick off a one-shot timer based off our pref value.  When this timer
     // fires, if painting is still locked down, then we will go ahead and
     // trigger a full invalidate and allow painting to proceed normally.
     mPaintingSuppressed = true;
     // Don't suppress painting if the document isn't loading.
     nsIDocument::ReadyState readyState = mDocument->GetReadyStateEnum();
     if (readyState != nsIDocument::READYSTATE_COMPLETE) {
       mPaintSuppressionTimer = do_CreateInstance("@mozilla.org/timer;1");
     }
     if (!mPaintSuppressionTimer) {
       mPaintingSuppressed = false;
     } else {
       // Initialize the timer.
       // Default to PAINTLOCK_EVENT_DELAY if we can't get the pref value.
       int32_t delay =
         Preferences::GetInt("nglayout.initialpaint.delay",
                             PAINTLOCK_EVENT_DELAY);
       mPaintSuppressionTimer->InitWithFuncCallback(sPaintSuppressionCallback,
                                                    this, delay,
                                                    nsITimer::TYPE_ONE_SHOT);
     }
   }
   if (root && root->IsXUL()) {
     mozilla::Telemetry::AccumulateTimeDelta(Telemetry::XUL_INITIAL_FRAME_CONSTRUCTION,
                                             timerStart);
   }
   return NS_OK; //XXX this needs to be real. MMP
 }
 void
 PresShell::sPaintSuppressionCallback(nsITimer *aTimer, void* aPresShell)
 {
   nsRefPtr<PresShell> self = static_cast<PresShell*>(aPresShell);
   if (self)
     self->UnsuppressPainting();
 }
 void
 PresShell::AsyncResizeEventCallback(nsITimer* aTimer, void* aPresShell)
 {
   static_cast<PresShell*>(aPresShell)->FireResizeEvent();
 }
 nsresult
 PresShell::ResizeReflowOverride(nscoord aWidth, nscoord aHeight)
 {
   mViewportOverridden = true;
   return ResizeReflowIgnoreOverride(aWidth, aHeight);
 }
 nsresult
 PresShell::ResizeReflow(nscoord aWidth, nscoord aHeight)
 {
   if (mViewportOverridden) {
     // The viewport has been overridden, and this reflow request
     // didn't ask to ignore the override.  Pretend it didn't happen.
     return NS_OK;
   }
   return ResizeReflowIgnoreOverride(aWidth, aHeight);
 }
 nsresult
 PresShell::ResizeReflowIgnoreOverride(nscoord aWidth, nscoord aHeight)
 {
   NS_PRECONDITION(!mIsReflowing, "Shouldn't be in reflow here!");
   NS_PRECONDITION(aWidth != NS_UNCONSTRAINEDSIZE,
                   "shouldn't use unconstrained widths anymore");
   // If we don't have a root frame yet, that means we haven't had our initial
   // reflow... If that's the case, and aWidth or aHeight is unconstrained,
   // ignore them altogether.
   nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
   if (!rootFrame && aHeight == NS_UNCONSTRAINEDSIZE) {
     // We can't do the work needed for SizeToContent without a root
     // frame, and we want to return before setting the visible area.
     return NS_ERROR_NOT_AVAILABLE;
   }
   mPresContext->SetVisibleArea(nsRect(0, 0, aWidth, aHeight));
   // There isn't anything useful we can do if the initial reflow hasn't happened.
   if (!rootFrame) {
     return NS_OK;
   }
   nsRefPtr<nsViewManager> viewManagerDeathGrip = mViewManager;
   // Take this ref after viewManager so it'll make sure to go away first.
   nsCOMPtr<nsIPresShell> kungFuDeathGrip(this);
   if (!GetPresContext()->SupressingResizeReflow()) {
     // Have to make sure that the content notifications are flushed before we
     // start messing with the frame model; otherwise we can get content doubling.
     mDocument->FlushPendingNotifications(Flush_ContentAndNotify);
     // Make sure style is up to date
     {
       nsAutoScriptBlocker scriptBlocker;
       mPresContext->RestyleManager()->ProcessPendingRestyles();
     }
     rootFrame = mFrameConstructor->GetRootFrame();
     if (!mIsDestroying && rootFrame) {
       // XXX Do a full invalidate at the beginning so that invalidates along
       // the way don't have region accumulation issues?
       {
         nsAutoCauseReflowNotifier crNotifier(this);
         WillDoReflow();
         // Kick off a top-down reflow
         AUTO_LAYOUT_PHASE_ENTRY_POINT(GetPresContext(), Reflow);
         nsViewManager::AutoDisableRefresh refreshBlocker(mViewManager);
         mDirtyRoots.RemoveElement(rootFrame);
         DoReflow(rootFrame, true);
       }
       DidDoReflow(true, false);
     }
   }
   rootFrame = mFrameConstructor->GetRootFrame();
   if (aHeight == NS_UNCONSTRAINEDSIZE && rootFrame) {
     mPresContext->SetVisibleArea(
       nsRect(0, 0, aWidth, rootFrame->GetRect().height));
   }
   if (!mIsDestroying && !mResizeEvent.IsPending() &&
       !mAsyncResizeTimerIsActive) {
     if (mInResize) {
       if (!mAsyncResizeEventTimer) {
         mAsyncResizeEventTimer = do_CreateInstance("@mozilla.org/timer;1");
       }
       if (mAsyncResizeEventTimer) {
         mAsyncResizeTimerIsActive = true;
         mAsyncResizeEventTimer->InitWithFuncCallback(AsyncResizeEventCallback,
                                                      this, 15,
                                                      nsITimer::TYPE_ONE_SHOT);
       }
     } else {
       nsRefPtr<nsRunnableMethod<PresShell> > resizeEvent =
         NS_NewRunnableMethod(this, &PresShell::FireResizeEvent);
       if (NS_SUCCEEDED(NS_DispatchToCurrentThread(resizeEvent))) {
         mResizeEvent = resizeEvent;
         mDocument->SetNeedStyleFlush();
       }
     }
   }
   return NS_OK; //XXX this needs to be real. MMP
 }
 void
 PresShell::FireResizeEvent()
 {
   if (mAsyncResizeTimerIsActive) {
     mAsyncResizeTimerIsActive = false;
     mAsyncResizeEventTimer->Cancel();
   }
   mResizeEvent.Revoke();
   if (mIsDocumentGone)
     return;
   //Send resize event from here.
   WidgetEvent event(true, NS_RESIZE_EVENT);
   nsEventStatus status = nsEventStatus_eIgnore;
   nsPIDOMWindow *window = mDocument->GetWindow();
   if (window) {
     nsCOMPtr<nsIPresShell> kungFuDeathGrip(this);
     mInResize = true;
     EventDispatcher::Dispatch(window, mPresContext, &event, nullptr, &status);
     mInResize = false;
   }
 }
 void
 PresShell::SetIgnoreFrameDestruction(bool aIgnore)
 {
   if (mDocument) {
     // We need to tell the ImageLoader to drop all its references to frames
     // because they're about to go away and it won't get notifications of that.
     mDocument->StyleImageLoader()->ClearFrames();
   }
   mIgnoreFrameDestruction = aIgnore;
 }
 void
 PresShell::NotifyDestroyingFrame(nsIFrame* aFrame)
 {
   if (!mIgnoreFrameDestruction) {
     mDocument->StyleImageLoader()->DropRequestsForFrame(aFrame);
     mFrameConstructor->NotifyDestroyingFrame(aFrame);
     for (int32_t idx = mDirtyRoots.Length(); idx; ) {
       --idx;
       if (mDirtyRoots[idx] == aFrame) {
         mDirtyRoots.RemoveElementAt(idx);
       }
     }
     // Remove frame properties
     mPresContext->NotifyDestroyingFrame(aFrame);
     if (aFrame == mCurrentEventFrame) {
       mCurrentEventContent = aFrame->GetContent();
       mCurrentEventFrame = nullptr;
     }
   #ifdef DEBUG
     if (aFrame == mDrawEventTargetFrame) {
       mDrawEventTargetFrame = nullptr;
     }
   #endif
     for (unsigned int i=0; i < mCurrentEventFrameStack.Length(); i++) {
       if (aFrame == mCurrentEventFrameStack.ElementAt(i)) {
         //One of our stack frames was deleted.  Get its content so that when we
         //pop it we can still get its new frame from its content
         nsIContent *currentEventContent = aFrame->GetContent();
         mCurrentEventContentStack.ReplaceObjectAt(currentEventContent, i);
         mCurrentEventFrameStack[i] = nullptr;
       }
     }
     mFramesToDirty.RemoveEntry(aFrame);
   } else {
     // We must delete this property in situ so that its destructor removes the
     // frame from FrameLayerBuilder::DisplayItemData::mFrameList -- otherwise
     // the DisplayItemData destructor will use the destroyed frame when it
     // tries to remove it from the (array) value of this property.
     mPresContext->PropertyTable()->
       Delete(aFrame, FrameLayerBuilder::LayerManagerDataProperty());
   }
 }
 already_AddRefed<nsCaret> PresShell::GetCaret() const
 {
   nsRefPtr<nsCaret> caret = mCaret;
   return caret.forget();
 }
 void PresShell::MaybeInvalidateCaretPosition()
 {
   if (mCaret) {
     mCaret->InvalidateOutsideCaret();
   }
 }
 void PresShell::SetCaret(nsCaret *aNewCaret)
 {
   mCaret = aNewCaret;
 }
 void PresShell::RestoreCaret()
 {
   mCaret = mOriginalCaret;
 }
 NS_IMETHODIMP PresShell::SetCaretEnabled(bool aInEnable)
 {
   bool oldEnabled = mCaretEnabled;
   mCaretEnabled = aInEnable;
   if (mCaret && (mCaretEnabled != oldEnabled))
   {
 /*  Don't change the caret's selection here! This was an evil side-effect of SetCaretEnabled()
     nsCOMPtr<nsIDOMSelection> domSel;
     if (NS_SUCCEEDED(GetSelection(nsISelectionController::SELECTION_NORMAL, getter_AddRefs(domSel))) && domSel)
       mCaret->SetCaretDOMSelection(domSel);
 */
     mCaret->SetCaretVisible(mCaretEnabled);
   }
   return NS_OK;
 }
 NS_IMETHODIMP PresShell::SetCaretReadOnly(bool aReadOnly)
 {
   if (mCaret)
     mCaret->SetCaretReadOnly(aReadOnly);
   return NS_OK;
 }
 NS_IMETHODIMP PresShell::GetCaretEnabled(bool *aOutEnabled)
 {
   NS_ENSURE_ARG_POINTER(aOutEnabled);
   *aOutEnabled = mCaretEnabled;
   return NS_OK;
 }
 NS_IMETHODIMP PresShell::SetCaretVisibilityDuringSelection(bool aVisibility)
 {
   if (mCaret)
     mCaret->SetVisibilityDuringSelection(aVisibility);
   return NS_OK;
 }
 NS_IMETHODIMP PresShell::GetCaretVisible(bool *aOutIsVisible)
 {
   *aOutIsVisible = false;
   if (mCaret) {
     nsresult rv = mCaret->GetCaretVisible(aOutIsVisible);
     NS_ENSURE_SUCCESS(rv,rv);
   }
   return NS_OK;
 }
 NS_IMETHODIMP PresShell::SetSelectionFlags(int16_t aInEnable)
 {
   mSelectionFlags = aInEnable;
   return NS_OK;
 }
 NS_IMETHODIMP PresShell::GetSelectionFlags(int16_t *aOutEnable)
 {
   if (!aOutEnable)
     return NS_ERROR_INVALID_ARG;
   *aOutEnable = mSelectionFlags;
   return NS_OK;
 }
 //implementation of nsISelectionController
 NS_IMETHODIMP
 PresShell::CharacterMove(bool aForward, bool aExtend)
 {
   return mSelection->CharacterMove(aForward, aExtend);
 }
 NS_IMETHODIMP
 PresShell::CharacterExtendForDelete()
 {
   return mSelection->CharacterExtendForDelete();
 }
 NS_IMETHODIMP
 PresShell::CharacterExtendForBackspace()
 {
   return mSelection->CharacterExtendForBackspace();
 }
 NS_IMETHODIMP
 PresShell::WordMove(bool aForward, bool aExtend)
 {
   nsresult result = mSelection->WordMove(aForward, aExtend);
 // if we can't go down/up any more we must then move caret completely to
 // end/beginning respectively.
   if (NS_FAILED(result))
     result = CompleteMove(aForward, aExtend);
   return result;
 }
 NS_IMETHODIMP
 PresShell::WordExtendForDelete(bool aForward)
 {
   return mSelection->WordExtendForDelete(aForward);
 }
 NS_IMETHODIMP
 PresShell::LineMove(bool aForward, bool aExtend)
 {
   nsresult result = mSelection->LineMove(aForward, aExtend);
 // if we can't go down/up any more we must then move caret completely to
 // end/beginning respectively.
   if (NS_FAILED(result))
     result = CompleteMove(aForward,aExtend);
   return result;
 }
 NS_IMETHODIMP
 PresShell::IntraLineMove(bool aForward, bool aExtend)
 {
   return mSelection->IntraLineMove(aForward, aExtend);
 }
 NS_IMETHODIMP
 PresShell::PageMove(bool aForward, bool aExtend)
 {
   nsIScrollableFrame *scrollableFrame =
     GetFrameToScrollAsScrollable(nsIPresShell::eVertical);
   if (!scrollableFrame)
     return NS_OK;
   mSelection->CommonPageMove(aForward, aExtend, scrollableFrame);
   // After ScrollSelectionIntoView(), the pending notifications might be
   // flushed and PresShell/PresContext/Frames may be dead. See bug 418470.
   return ScrollSelectionIntoView(nsISelectionController::SELECTION_NORMAL,
                                  nsISelectionController::SELECTION_FOCUS_REGION,
                                  nsISelectionController::SCROLL_SYNCHRONOUS);
 }
 NS_IMETHODIMP
 PresShell::ScrollPage(bool aForward)
 {
   nsIScrollableFrame* scrollFrame =
     GetFrameToScrollAsScrollable(nsIPresShell::eVertical);
   if (scrollFrame) {
     scrollFrame->ScrollBy(nsIntPoint(0, aForward ? 1 : -1),
                           nsIScrollableFrame::PAGES,
                           nsIScrollableFrame::SMOOTH);
   }
   return NS_OK;
 }
 NS_IMETHODIMP
 PresShell::ScrollLine(bool aForward)
 {
   nsIScrollableFrame* scrollFrame =
     GetFrameToScrollAsScrollable(nsIPresShell::eVertical);
   if (scrollFrame) {
     int32_t lineCount = Preferences::GetInt("toolkit.scrollbox.verticalScrollDistance",
                                             NS_DEFAULT_VERTICAL_SCROLL_DISTANCE);
     scrollFrame->ScrollBy(nsIntPoint(0, aForward ? lineCount : -lineCount),
                           nsIScrollableFrame::LINES,
                           nsIScrollableFrame::SMOOTH);
   }
   return NS_OK;
 }
 NS_IMETHODIMP
 PresShell::ScrollCharacter(bool aRight)
 {
   nsIScrollableFrame* scrollFrame =
     GetFrameToScrollAsScrollable(nsIPresShell::eHorizontal);
   if (scrollFrame) {
     int32_t h = Preferences::GetInt("toolkit.scrollbox.horizontalScrollDistance",
                                     NS_DEFAULT_HORIZONTAL_SCROLL_DISTANCE);
     scrollFrame->ScrollBy(nsIntPoint(aRight ? h : -h, 0),
                           nsIScrollableFrame::LINES,
                           nsIScrollableFrame::SMOOTH);
   }
   return NS_OK;
 }
 NS_IMETHODIMP
 PresShell::CompleteScroll(bool aForward)
 {
   nsIScrollableFrame* scrollFrame =
     GetFrameToScrollAsScrollable(nsIPresShell::eVertical);
   if (scrollFrame) {
     scrollFrame->ScrollBy(nsIntPoint(0, aForward ? 1 : -1),
                           nsIScrollableFrame::WHOLE,
                           nsIScrollableFrame::SMOOTH);
   }
   return NS_OK;
 }
 NS_IMETHODIMP
 PresShell::CompleteMove(bool aForward, bool aExtend)
 {
   // Beware! This may flush notifications via synchronous
   // ScrollSelectionIntoView.
   nsIContent* limiter = mSelection->GetAncestorLimiter();
   nsIFrame* frame = limiter ? limiter->GetPrimaryFrame()
                             : FrameConstructor()->GetRootElementFrame();
   if (!frame)
     return NS_ERROR_FAILURE;
   nsIFrame::CaretPosition pos =
     frame->GetExtremeCaretPosition(!aForward);
   mSelection->HandleClick(pos.mResultContent, pos.mContentOffset,
                           pos.mContentOffset, aExtend, false, aForward);
   if (limiter) {
     // HandleClick resets ancestorLimiter, so set it again.
     mSelection->SetAncestorLimiter(limiter);
   }
   // After ScrollSelectionIntoView(), the pending notifications might be
   // flushed and PresShell/PresContext/Frames may be dead. See bug 418470.
   return ScrollSelectionIntoView(nsISelectionController::SELECTION_NORMAL,
                                  nsISelectionController::SELECTION_FOCUS_REGION,
                                  nsISelectionController::SCROLL_SYNCHRONOUS);
 }
 NS_IMETHODIMP
 PresShell::SelectAll()
 {
   return mSelection->SelectAll();
 }
 static void
 DoCheckVisibility(nsPresContext* aPresContext,
                   nsIContent* aNode,
                   int16_t aStartOffset,
                   int16_t aEndOffset,
                   bool* aRetval)
 {
   nsIFrame* frame = aNode->GetPrimaryFrame();
   if (!frame) {
     // No frame to look at so it must not be visible.
     return;
   }
   // Start process now to go through all frames to find startOffset. Then check
   // chars after that to see if anything until EndOffset is visible.
   bool finished = false;
   frame->CheckVisibility(aPresContext, aStartOffset, aEndOffset, true,
                          &finished, aRetval);
   // Don't worry about other return value.
 }
 NS_IMETHODIMP
 PresShell::CheckVisibility(nsIDOMNode *node, int16_t startOffset, int16_t EndOffset, bool *_retval)
 {
   if (!node || startOffset>EndOffset || !_retval || startOffset<0 || EndOffset<0)
     return NS_ERROR_INVALID_ARG;
   *_retval = false; //initialize return parameter
   nsCOMPtr<nsIContent> content(do_QueryInterface(node));
   if (!content)
     return NS_ERROR_FAILURE;
   DoCheckVisibility(mPresContext, content, startOffset, EndOffset, _retval);
   return NS_OK;
 }
 nsresult
 PresShell::CheckVisibilityContent(nsIContent* aNode, int16_t aStartOffset,
                                   int16_t aEndOffset, bool* aRetval)
 {
   if (!aNode || aStartOffset > aEndOffset || !aRetval ||
       aStartOffset < 0 || aEndOffset < 0) {
     return NS_ERROR_INVALID_ARG;
   }
   *aRetval = false;
   DoCheckVisibility(mPresContext, aNode, aStartOffset, aEndOffset, aRetval);
   return NS_OK;
 }
 //end implementations nsISelectionController
 nsIFrame*
 nsIPresShell::GetRootFrameExternal() const
 {
   return mFrameConstructor->GetRootFrame();
 }
 nsIFrame*
 nsIPresShell::GetRootScrollFrame() const
 {
   nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
   // Ensure root frame is a viewport frame
   if (!rootFrame || nsGkAtoms::viewportFrame != rootFrame->GetType())
     return nullptr;
   nsIFrame* theFrame = rootFrame->GetFirstPrincipalChild();
   if (!theFrame || nsGkAtoms::scrollFrame != theFrame->GetType())
     return nullptr;
   return theFrame;
 }
 nsIScrollableFrame*
 nsIPresShell::GetRootScrollFrameAsScrollable() const
 {
   nsIFrame* frame = GetRootScrollFrame();
   if (!frame)
     return nullptr;
   nsIScrollableFrame* scrollableFrame = do_QueryFrame(frame);
   NS_ASSERTION(scrollableFrame,
                "All scroll frames must implement nsIScrollableFrame");
   return scrollableFrame;
 }
 nsIScrollableFrame*
 nsIPresShell::GetRootScrollFrameAsScrollableExternal() const
 {
   return GetRootScrollFrameAsScrollable();
 }
 nsIPageSequenceFrame*
 PresShell::GetPageSequenceFrame() const
 {
   nsIFrame* frame = mFrameConstructor->GetPageSequenceFrame();
   return do_QueryFrame(frame);
 }
 void
 PresShell::BeginUpdate(nsIDocument *aDocument, nsUpdateType aUpdateType)
 {
 #ifdef DEBUG
   mUpdateCount++;
 #endif
   mFrameConstructor->BeginUpdate();
   if (aUpdateType & UPDATE_STYLE)
     mStyleSet->BeginUpdate();
 }
 void
 PresShell::EndUpdate(nsIDocument *aDocument, nsUpdateType aUpdateType)
 {
 #ifdef DEBUG
   NS_PRECONDITION(0 != mUpdateCount, "too many EndUpdate's");
   --mUpdateCount;
 #endif
   if (aUpdateType & UPDATE_STYLE) {
     mStyleSet->EndUpdate();
     if (mStylesHaveChanged || !mChangedScopeStyleRoots.IsEmpty())
       ReconstructStyleData();
   }
   mFrameConstructor->EndUpdate();
 }
 void
 PresShell::RestoreRootScrollPosition()
 {
   nsIScrollableFrame* scrollableFrame = GetRootScrollFrameAsScrollable();
   if (scrollableFrame) {
     scrollableFrame->ScrollToRestoredPosition();
   }
 }
 void
 PresShell::BeginLoad(nsIDocument *aDocument)
 {
   mDocumentLoading = true;
 #ifdef PR_LOGGING
   gfxTextPerfMetrics *tp = nullptr;
   if (mPresContext) {
     tp = mPresContext->GetTextPerfMetrics();
   }
   bool shouldLog = gLog && PR_LOG_TEST(gLog, PR_LOG_DEBUG);
   if (shouldLog || tp) {
     mLoadBegin = TimeStamp::Now();
   }
   if (shouldLog) {
     nsIURI* uri = mDocument->GetDocumentURI();
     nsAutoCString spec;
     if (uri) {
       uri->GetSpec(spec);
     }
     PR_LOG(gLog, PR_LOG_DEBUG,
            ("(presshell) %p load begin [%s]\n",
             this, spec.get()));
   }
 #endif
 }
 void
 PresShell::EndLoad(nsIDocument *aDocument)
 {
   NS_PRECONDITION(aDocument == mDocument, "Wrong document");
   RestoreRootScrollPosition();
   mDocumentLoading = false;
 }
 void
 PresShell::LoadComplete()
 {
 #ifdef PR_LOGGING
   gfxTextPerfMetrics *tp = nullptr;
   if (mPresContext) {
     tp = mPresContext->GetTextPerfMetrics();
   }
   // log load
   bool shouldLog = gLog && PR_LOG_TEST(gLog, PR_LOG_DEBUG);
   if (shouldLog || tp) {
     TimeDuration loadTime = TimeStamp::Now() - mLoadBegin;
     nsIURI* uri = mDocument->GetDocumentURI();
     nsAutoCString spec;
     if (uri) {
       uri->GetSpec(spec);
     }
     if (shouldLog) {
       PR_LOG(gLog, PR_LOG_DEBUG,
              ("(presshell) %p load done time-ms: %9.2f [%s]\n",
               this, loadTime.ToMilliseconds(), spec.get()));
     }
     if (tp) {
       tp->Accumulate();
       if (tp->cumulative.numChars > 0) {
         LogTextPerfStats(tp, this, tp->cumulative, loadTime.ToMilliseconds(),
                          eLog_loaddone, spec.get());
       }
     }
   }
 #endif
 }
 #ifdef DEBUG
 void
 PresShell::VerifyHasDirtyRootAncestor(nsIFrame* aFrame)
 {
   // XXXbz due to bug 372769, can't actually assert anything here...
   return;
   // XXXbz shouldn't need this part; remove it once FrameNeedsReflow
   // handles the root frame correctly.
   if (!aFrame->GetParent()) {
     return;
   }
   // Make sure that there is a reflow root ancestor of |aFrame| that's
   // in mDirtyRoots already.
   while (aFrame && (aFrame->GetStateBits() & NS_FRAME_HAS_DIRTY_CHILDREN)) {
     if (((aFrame->GetStateBits() & NS_FRAME_REFLOW_ROOT) ||
          !aFrame->GetParent()) &&
         mDirtyRoots.Contains(aFrame)) {
       return;
     }
     aFrame = aFrame->GetParent();
   }
   NS_NOTREACHED("Frame has dirty bits set but isn't scheduled to be "
                 "reflowed?");
 }
 #endif
 void
 PresShell::FrameNeedsReflow(nsIFrame *aFrame, IntrinsicDirty aIntrinsicDirty,
                             nsFrameState aBitToAdd)
 {
   NS_PRECONDITION(aBitToAdd == NS_FRAME_IS_DIRTY ||
                   aBitToAdd == NS_FRAME_HAS_DIRTY_CHILDREN ||
                   !aBitToAdd,
                   "Unexpected bits being added");
   NS_PRECONDITION(!(aIntrinsicDirty == eStyleChange &&
                     aBitToAdd == NS_FRAME_HAS_DIRTY_CHILDREN),
                   "bits don't correspond to style change reason");
   NS_ASSERTION(!mIsReflowing, "can't mark frame dirty during reflow");
   // If we've not yet done the initial reflow, then don't bother
   // enqueuing a reflow command yet.
   if (! mDidInitialize)
     return;
   // If we're already destroying, don't bother with this either.
   if (mIsDestroying)
     return;
 #ifdef DEBUG
   //printf("gShellCounter: %d\n", gShellCounter++);
   if (mInVerifyReflow)
     return;
   if (VERIFY_REFLOW_NOISY_RC & gVerifyReflowFlags) {
     printf("\nPresShell@%p: frame %p needs reflow\n", (void*)this, (void*)aFrame);
     if (VERIFY_REFLOW_REALLY_NOISY_RC & gVerifyReflowFlags) {
       printf("Current content model:\n");
       Element *rootElement = mDocument->GetRootElement();
       if (rootElement) {
         rootElement->List(stdout, 0);
       }
     }
   }
 #endif
   nsAutoTArray<nsIFrame*, 4> subtrees;
   subtrees.AppendElement(aFrame);
   do {
     nsIFrame *subtreeRoot = subtrees.ElementAt(subtrees.Length() - 1);
     subtrees.RemoveElementAt(subtrees.Length() - 1);
     // Grab |wasDirty| now so we can go ahead and update the bits on
     // subtreeRoot.
     bool wasDirty = NS_SUBTREE_DIRTY(subtreeRoot);
     subtreeRoot->AddStateBits(aBitToAdd);
     // Now if subtreeRoot is a reflow root we can cut off this reflow at it if
     // the bit being added is NS_FRAME_HAS_DIRTY_CHILDREN.
     bool targetFrameDirty = (aBitToAdd == NS_FRAME_IS_DIRTY);
 #define FRAME_IS_REFLOW_ROOT(_f)                   \
   ((_f->GetStateBits() & NS_FRAME_REFLOW_ROOT) &&  \
    (_f != subtreeRoot || !targetFrameDirty))
     // Mark the intrinsic widths as dirty on the frame, all of its ancestors,
     // and all of its descendants, if needed:
     if (aIntrinsicDirty != eResize) {
       // Mark argument and all ancestors dirty. (Unless we hit a reflow
       // root that should contain the reflow.  That root could be
       // subtreeRoot itself if it's not dirty, or it could be some
       // ancestor of subtreeRoot.)
       for (nsIFrame *a = subtreeRoot;
            a && !FRAME_IS_REFLOW_ROOT(a);
            a = a->GetParent())
         a->MarkIntrinsicWidthsDirty();
     }
     if (aIntrinsicDirty == eStyleChange) {
       // Mark all descendants dirty (using an nsTArray stack rather than
       // recursion).
       // Note that nsHTMLReflowState::InitResizeFlags has some similar
       // code; see comments there for how and why it differs.
       nsAutoTArray<nsIFrame*, 32> stack;
       stack.AppendElement(subtreeRoot);
       do {
         nsIFrame *f = stack.ElementAt(stack.Length() - 1);
         stack.RemoveElementAt(stack.Length() - 1);
         if (f->GetType() == nsGkAtoms::placeholderFrame) {
           nsIFrame *oof = nsPlaceholderFrame::GetRealFrameForPlaceholder(f);
           if (!nsLayoutUtils::IsProperAncestorFrame(subtreeRoot, oof)) {
             // We have another distinct subtree we need to mark.
             subtrees.AppendElement(oof);
           }
         }
         nsIFrame::ChildListIterator lists(f);
         for (; !lists.IsDone(); lists.Next()) {
           nsFrameList::Enumerator childFrames(lists.CurrentList());
           for (; !childFrames.AtEnd(); childFrames.Next()) {
             nsIFrame* kid = childFrames.get();
             kid->MarkIntrinsicWidthsDirty();
             stack.AppendElement(kid);
           }
         }
       } while (stack.Length() != 0);
     }
     // Skip setting dirty bits up the tree if we weren't given a bit to add.
     if (!aBitToAdd) {
       continue;
     }
     // Set NS_FRAME_HAS_DIRTY_CHILDREN bits (via nsIFrame::ChildIsDirty)
     // up the tree until we reach either a frame that's already dirty or
     // a reflow root.
     nsIFrame *f = subtreeRoot;
     for (;;) {
       if (FRAME_IS_REFLOW_ROOT(f) || !f->GetParent()) {
         // we've hit a reflow root or the root frame
         if (!wasDirty) {
           mDirtyRoots.AppendElement(f);
           mDocument->SetNeedLayoutFlush();
         }
 #ifdef DEBUG
         else {
           VerifyHasDirtyRootAncestor(f);
         }
 #endif
         break;
       }
       nsIFrame *child = f;
       f = f->GetParent();
       wasDirty = NS_SUBTREE_DIRTY(f);
       f->ChildIsDirty(child);
       NS_ASSERTION(f->GetStateBits() & NS_FRAME_HAS_DIRTY_CHILDREN,
                    "ChildIsDirty didn't do its job");
       if (wasDirty) {
         // This frame was already marked dirty.
 #ifdef DEBUG
         VerifyHasDirtyRootAncestor(f);
 #endif
         break;
       }
     }
   } while (subtrees.Length() != 0);
   MaybeScheduleReflow();
 }
 void
 PresShell::FrameNeedsToContinueReflow(nsIFrame *aFrame)
 {
   NS_ASSERTION(mIsReflowing, "Must be in reflow when marking path dirty.");
   NS_PRECONDITION(mCurrentReflowRoot, "Must have a current reflow root here");
   NS_ASSERTION(aFrame == mCurrentReflowRoot ||
                nsLayoutUtils::IsProperAncestorFrame(mCurrentReflowRoot, aFrame),
                "Frame passed in is not the descendant of mCurrentReflowRoot");
   NS_ASSERTION(aFrame->GetStateBits() & NS_FRAME_IN_REFLOW,
                "Frame passed in not in reflow?");
   mFramesToDirty.PutEntry(aFrame);
 }
 nsIScrollableFrame*
 nsIPresShell::GetFrameToScrollAsScrollable(
                 nsIPresShell::ScrollDirection aDirection)
 {
   nsIScrollableFrame* scrollFrame = nullptr;
   nsCOMPtr<nsIContent> focusedContent;
   nsIFocusManager* fm = nsFocusManager::GetFocusManager();
   if (fm && mDocument) {
     nsCOMPtr<nsIDOMWindow> window = do_QueryInterface(mDocument->GetWindow());
     nsCOMPtr<nsIDOMElement> focusedElement;
     fm->GetFocusedElementForWindow(window, false, nullptr, getter_AddRefs(focusedElement));
     focusedContent = do_QueryInterface(focusedElement);
   }
   if (!focusedContent && mSelection) {
     nsISelection* domSelection = mSelection->
       GetSelection(nsISelectionController::SELECTION_NORMAL);
     if (domSelection) {
       nsCOMPtr<nsIDOMNode> focusedNode;
       domSelection->GetFocusNode(getter_AddRefs(focusedNode));
       focusedContent = do_QueryInterface(focusedNode);
     }
   }
   if (focusedContent) {
     nsIFrame* startFrame = focusedContent->GetPrimaryFrame();
     if (startFrame) {
       scrollFrame = startFrame->GetScrollTargetFrame();
       if (scrollFrame) {
         startFrame = scrollFrame->GetScrolledFrame();
       }
       if (aDirection == nsIPresShell::eEither) {
         scrollFrame =
           nsLayoutUtils::GetNearestScrollableFrame(startFrame);
       } else {
         scrollFrame =
           nsLayoutUtils::GetNearestScrollableFrameForDirection(startFrame,
             aDirection == eVertical ? nsLayoutUtils::eVertical :
                                       nsLayoutUtils::eHorizontal);
       }
     }
   }
   if (!scrollFrame) {
     scrollFrame = GetRootScrollFrameAsScrollable();
   }
   return scrollFrame;
 }
 void
 PresShell::CancelAllPendingReflows()
 {
   mDirtyRoots.Clear();
   if (mReflowScheduled) {
     GetPresContext()->RefreshDriver()->RemoveLayoutFlushObserver(this);
     mReflowScheduled = false;
   }
   ASSERT_REFLOW_SCHEDULED_STATE();
 }
 nsresult
 PresShell::RecreateFramesFor(nsIContent* aContent)
 {
   NS_ENSURE_TRUE(mPresContext, NS_ERROR_FAILURE);
   if (!mDidInitialize) {
     // Nothing to do here.  In fact, if we proceed and aContent is the
     // root we will crash.
     return NS_OK;
   }
   // Don't call RecreateFramesForContent since that is not exported and we want
   // to keep the number of entrypoints down.
   NS_ASSERTION(mViewManager, "Should have view manager");
   // Have to make sure that the content notifications are flushed before we
   // start messing with the frame model; otherwise we can get content doubling.
   mDocument->FlushPendingNotifications(Flush_ContentAndNotify);
   nsAutoScriptBlocker scriptBlocker;
   nsStyleChangeList changeList;
   changeList.AppendChange(nullptr, aContent, nsChangeHint_ReconstructFrame);
   // Mark ourselves as not safe to flush while we're doing frame construction.
   ++mChangeNestCount;
   RestyleManager* restyleManager = mPresContext->RestyleManager();
   nsresult rv = restyleManager->ProcessRestyledFrames(changeList);
   restyleManager->FlushOverflowChangedTracker();
   --mChangeNestCount;
   return rv;
 }
 void
 nsIPresShell::PostRecreateFramesFor(Element* aElement)
 {
   mPresContext->RestyleManager()->PostRestyleEvent(aElement, nsRestyleHint(0),
                                                    nsChangeHint_ReconstructFrame);
 }
 void
 nsIPresShell::RestyleForAnimation(Element* aElement, nsRestyleHint aHint)
 {
   mPresContext->RestyleManager()->PostAnimationRestyleEvent(aElement, aHint,
                                                             NS_STYLE_HINT_NONE);
 }
 void
 nsIPresShell::SetForwardingContainer(const WeakPtr<nsDocShell> &aContainer)
 {
   mForwardingContainer = aContainer;
 }
 void
 PresShell::ClearFrameRefs(nsIFrame* aFrame)
 {
   mPresContext->EventStateManager()->ClearFrameRefs(aFrame);
   nsWeakFrame* weakFrame = mWeakFrames;
   while (weakFrame) {
     nsWeakFrame* prev = weakFrame->GetPreviousWeakFrame();
     if (weakFrame->GetFrame() == aFrame) {
       // This removes weakFrame from mWeakFrames.
       weakFrame->Clear(this);
     }
     weakFrame = prev;
   }
 }
 already_AddRefed<nsRenderingContext>
 PresShell::CreateReferenceRenderingContext()
 {
   nsDeviceContext* devCtx = mPresContext->DeviceContext();
   nsRefPtr<nsRenderingContext> rc;
   if (mPresContext->IsScreen()) {
     rc = new nsRenderingContext();
     rc->Init(devCtx, gfxPlatform::GetPlatform()->ScreenReferenceSurface());
   } else {
     rc = devCtx->CreateRenderingContext();
   }
   MOZ_ASSERT(rc, "shouldn't break promise to return non-null");
   return rc.forget();
 }
 nsresult
 PresShell::GoToAnchor(const nsAString& aAnchorName, bool aScroll)
 {
   if (!mDocument) {
     return NS_ERROR_FAILURE;
   }
   const Element *root = mDocument->GetRootElement();
   if (root && root->IsSVG(nsGkAtoms::svg)) {
     // We need to execute this even if there is an empty anchor name
     // so that any existing SVG fragment identifier effect is removed
     if (SVGFragmentIdentifier::ProcessFragmentIdentifier(mDocument, aAnchorName)) {
       return NS_OK;
     }
   }
   // Hold a reference to the ESM in case event dispatch tears us down.
   nsRefPtr<EventStateManager> esm = mPresContext->EventStateManager();
   if (aAnchorName.IsEmpty()) {
     NS_ASSERTION(!aScroll, "can't scroll to empty anchor name");
     esm->SetContentState(nullptr, NS_EVENT_STATE_URLTARGET);
     return NS_OK;
   }
   nsCOMPtr<nsIDOMHTMLDocument> htmlDoc = do_QueryInterface(mDocument);
   nsresult rv = NS_OK;
   nsCOMPtr<nsIContent> content;
   // Search for an element with a matching "id" attribute
   if (mDocument) {
     content = mDocument->GetElementById(aAnchorName);
   }
   // Search for an anchor element with a matching "name" attribute
   if (!content && htmlDoc) {
     nsCOMPtr<nsIDOMNodeList> list;
     // Find a matching list of named nodes
     rv = htmlDoc->GetElementsByName(aAnchorName, getter_AddRefs(list));
     if (NS_SUCCEEDED(rv) && list) {
       uint32_t i;
       // Loop through the named nodes looking for the first anchor
       for (i = 0; true; i++) {
         nsCOMPtr<nsIDOMNode> node;
         rv = list->Item(i, getter_AddRefs(node));
         if (!node) {  // End of list
           break;
         }
         // Ensure it's an anchor element
         content = do_QueryInterface(node);
         if (content) {
           if (content->Tag() == nsGkAtoms::a && content->IsHTML()) {
             break;
           }
           content = nullptr;
         }
       }
     }
   }
   // Search for anchor in the HTML namespace with a matching name
   if (!content && !htmlDoc)
   {
     nsCOMPtr<nsIDOMDocument> doc = do_QueryInterface(mDocument);
     nsCOMPtr<nsIDOMNodeList> list;
     NS_NAMED_LITERAL_STRING(nameSpace, "http://www.w3.org/1999/xhtml");
     // Get the list of anchor elements
     rv = doc->GetElementsByTagNameNS(nameSpace, NS_LITERAL_STRING("a"), getter_AddRefs(list));
     if (NS_SUCCEEDED(rv) && list) {
       uint32_t i;
       // Loop through the named nodes looking for the first anchor
       for (i = 0; true; i++) {
         nsCOMPtr<nsIDOMNode> node;
         rv = list->Item(i, getter_AddRefs(node));
         if (!node) { // End of list
           break;
         }
         // Compare the name attribute
         nsCOMPtr<nsIDOMElement> element = do_QueryInterface(node);
         nsAutoString value;
         if (element && NS_SUCCEEDED(element->GetAttribute(NS_LITERAL_STRING("name"), value))) {
           if (value.Equals(aAnchorName)) {
             content = do_QueryInterface(element);
             break;
           }
         }
       }
     }
   }
   esm->SetContentState(content, NS_EVENT_STATE_URLTARGET);
 #ifdef ACCESSIBILITY
   nsIContent *anchorTarget = content;
 #endif
   nsIScrollableFrame* rootScroll = GetRootScrollFrameAsScrollable();
   if (rootScroll && rootScroll->DidHistoryRestore()) {
     // Scroll position restored from history trumps scrolling to anchor.
     aScroll = false;
     rootScroll->ClearDidHistoryRestore();
   }
   if (content) {
     if (aScroll) {
       rv = ScrollContentIntoView(content,
                                  ScrollAxis(SCROLL_TOP, SCROLL_ALWAYS),
                                  ScrollAxis(),
                                  ANCHOR_SCROLL_FLAGS);
       NS_ENSURE_SUCCESS(rv, rv);
       nsIScrollableFrame* rootScroll = GetRootScrollFrameAsScrollable();
       if (rootScroll) {
         mLastAnchorScrolledTo = content;
         mLastAnchorScrollPositionY = rootScroll->GetScrollPosition().y;
       }
     }
     // Should we select the target? This action is controlled by a
     // preference: the default is to not select.
     bool selectAnchor = Preferences::GetBool("layout.selectanchor");
     // Even if select anchor pref is false, we must still move the
     // caret there. That way tabbing will start from the new
     // location
     nsRefPtr<nsIDOMRange> jumpToRange = new nsRange(mDocument);
     while (content && content->GetFirstChild()) {
       content = content->GetFirstChild();
     }
     nsCOMPtr<nsIDOMNode> node(do_QueryInterface(content));
     NS_ASSERTION(node, "No nsIDOMNode for descendant of anchor");
     jumpToRange->SelectNodeContents(node);
     // Select the anchor
     nsISelection* sel = mSelection->
       GetSelection(nsISelectionController::SELECTION_NORMAL);
     if (sel) {
       sel->RemoveAllRanges();
       sel->AddRange(jumpToRange);
       if (!selectAnchor) {
         // Use a caret (collapsed selection) at the start of the anchor
         sel->CollapseToStart();
       }
     }
     // Selection is at anchor.
     // Now focus the document itself if focus is on an element within it.
     nsPIDOMWindow *win = mDocument->GetWindow();
     nsIFocusManager* fm = nsFocusManager::GetFocusManager();
     if (fm && win) {
       nsCOMPtr<nsIDOMWindow> focusedWindow;
       fm->GetFocusedWindow(getter_AddRefs(focusedWindow));
       if (SameCOMIdentity(win, focusedWindow)) {
         fm->ClearFocus(focusedWindow);
       }
     }
     // If the target is an animation element, activate the animation
     if (content->IsNodeOfType(nsINode::eANIMATION)) {
       SVGContentUtils::ActivateByHyperlink(content.get());
     }
   } else {
     rv = NS_ERROR_FAILURE;
     NS_NAMED_LITERAL_STRING(top, "top");
     if (nsContentUtils::EqualsIgnoreASCIICase(aAnchorName, top)) {
       // Scroll to the top/left if aAnchorName is "top" and there is no element
       // with such a name or id.
       rv = NS_OK;
       nsIScrollableFrame* sf = GetRootScrollFrameAsScrollable();
       // Check |aScroll| after setting |rv| so we set |rv| to the same
       // thing whether or not |aScroll| is true.
       if (aScroll && sf) {
         // Scroll to the top of the page
         sf->ScrollTo(nsPoint(0, 0), nsIScrollableFrame::INSTANT);
       }
     }
   }
 #ifdef ACCESSIBILITY
   if (anchorTarget) {
     nsAccessibilityService* accService = AccService();
     if (accService)
       accService->NotifyOfAnchorJumpTo(anchorTarget);
   }
 #endif
   return rv;
 }
 nsresult
 PresShell::ScrollToAnchor()
 {
   if (!mLastAnchorScrolledTo) {
     return NS_OK;
   }
   NS_ASSERTION(mDidInitialize, "should have done initial reflow by now");
   nsIScrollableFrame* rootScroll = GetRootScrollFrameAsScrollable();
   if (!rootScroll ||
       mLastAnchorScrollPositionY != rootScroll->GetScrollPosition().y) {
     return NS_OK;
   }
   nsresult rv = ScrollContentIntoView(mLastAnchorScrolledTo,
                                       ScrollAxis(SCROLL_TOP, SCROLL_ALWAYS),
                                       ScrollAxis(),
                                       ANCHOR_SCROLL_FLAGS);
   mLastAnchorScrolledTo = nullptr;
   return rv;
 }
 /*
  * Helper (per-continuation) for ScrollContentIntoView.
  *
  * @param aContainerFrame [in] the frame which aRect is relative to
  * @param aFrame [in] Frame whose bounds should be unioned
  * @param aUseWholeLineHeightForInlines [in] if true, then for inline frames
  * we should include the top of the line in the added rectangle
  * @param aRect [inout] rect into which its bounds should be unioned
  * @param aHaveRect [inout] whether aRect contains data yet
  * @param aPrevBlock [inout] the block aLines is a line iterator for
  * @param aLines [inout] the line iterator we're using
  * @param aCurLine [inout] the line to start looking from in this iterator
  */
 static void
 AccumulateFrameBounds(nsIFrame* aContainerFrame,
                       nsIFrame* aFrame,
                       bool aUseWholeLineHeightForInlines,
                       nsRect& aRect,
                       bool& aHaveRect,
                       nsIFrame*& aPrevBlock,
                       nsAutoLineIterator& aLines,
                       int32_t& aCurLine)
 {
   nsIFrame* frame = aFrame;
   nsRect frameBounds = nsRect(nsPoint(0, 0), aFrame->GetSize());
   // If this is an inline frame and either the bounds height is 0 (quirks
   // layout model) or aUseWholeLineHeightForInlines is set, we need to
   // change the top of the bounds to include the whole line.
   if (frameBounds.height == 0 || aUseWholeLineHeightForInlines) {
     nsIFrame *prevFrame = aFrame;
     nsIFrame *f = aFrame;
     while (f && f->IsFrameOfType(nsIFrame::eLineParticipant) &&
            !f->IsTransformed() && !f->IsPositioned()) {
       prevFrame = f;
       f = prevFrame->GetParent();
     }
     if (f != aFrame &&
         f &&
         f->GetType() == nsGkAtoms::blockFrame) {
       // find the line containing aFrame and increase the top of |offset|.
       if (f != aPrevBlock) {
         aLines = f->GetLineIterator();
         aPrevBlock = f;
         aCurLine = 0;
       }
       if (aLines) {
         int32_t index = aLines->FindLineContaining(prevFrame, aCurLine);
         if (index >= 0) {
           aCurLine = index;
           nsIFrame *trash1;
           int32_t trash2;
           nsRect lineBounds;
           uint32_t trash3;
           if (NS_SUCCEEDED(aLines->GetLine(index, &trash1, &trash2,
                                            lineBounds, &trash3))) {
             frameBounds += frame->GetOffsetTo(f);
             frame = f;
             if (lineBounds.y < frameBounds.y) {
               frameBounds.height = frameBounds.YMost() - lineBounds.y;
               frameBounds.y = lineBounds.y;
             }
           }
         }
       }
     }
   }
   nsRect transformedBounds = nsLayoutUtils::TransformFrameRectToAncestor(frame,
     frameBounds, aContainerFrame);
   if (aHaveRect) {
     // We can't use nsRect::UnionRect since it drops empty rects on
     // the floor, and we need to include them.  (Thus we need
     // aHaveRect to know when to drop the initial value on the floor.)
     aRect.UnionRectEdges(aRect, transformedBounds);
   } else {
     aHaveRect = true;
     aRect = transformedBounds;
   }
 }
 static bool
 ComputeNeedToScroll(nsIPresShell::WhenToScroll aWhenToScroll,
                     nscoord                    aLineSize,
                     nscoord                    aRectMin,
                     nscoord                    aRectMax,
                     nscoord                    aViewMin,
                     nscoord                    aViewMax) {
   // See how the rect should be positioned vertically
   if (nsIPresShell::SCROLL_ALWAYS == aWhenToScroll) {
     // The caller wants the frame as visible as possible
     return true;
   } else if (nsIPresShell::SCROLL_IF_NOT_VISIBLE == aWhenToScroll) {
     // Scroll only if no part of the frame is visible in this view
     return aRectMax - aLineSize <= aViewMin ||
            aRectMin + aLineSize >= aViewMax;
   } else if (nsIPresShell::SCROLL_IF_NOT_FULLY_VISIBLE == aWhenToScroll) {
     // Scroll only if part of the frame is hidden and more can fit in view
     return !(aRectMin >= aViewMin && aRectMax <= aViewMax) &&
       std::min(aViewMax, aRectMax) - std::max(aRectMin, aViewMin) < aViewMax - aViewMin;
   }
   return false;
 }
 static nscoord
 ComputeWhereToScroll(int16_t aWhereToScroll,
                      nscoord aOriginalCoord,
                      nscoord aRectMin,
                      nscoord aRectMax,
                      nscoord aViewMin,
                      nscoord aViewMax,
                      nscoord* aRangeMin,
                      nscoord* aRangeMax) {
   nscoord resultCoord = aOriginalCoord;
   // Allow the scroll operation to land anywhere that
   // makes the whole rectangle visible.
   if (nsIPresShell::SCROLL_MINIMUM == aWhereToScroll) {
     if (aRectMin < aViewMin) {
       // Scroll up so the frame's top edge is visible
       resultCoord = aRectMin;
     } else if (aRectMax > aViewMax) {
       // Scroll down so the frame's bottom edge is visible. Make sure the
       // frame's top edge is still visible
       resultCoord = aOriginalCoord + aRectMax - aViewMax;
       if (resultCoord > aRectMin) {
         resultCoord = aRectMin;
       }
     }
   } else {
     nscoord frameAlignCoord =
       NSToCoordRound(aRectMin + (aRectMax - aRectMin) * (aWhereToScroll / 100.0f));
     resultCoord =  NSToCoordRound(frameAlignCoord - (aViewMax - aViewMin) * (
                                   aWhereToScroll / 100.0f));
   }
   nscoord scrollPortLength = aViewMax - aViewMin;
   // Force the scroll range to extend to include resultCoord.
   *aRangeMin = std::min(resultCoord, aRectMax - scrollPortLength);
   *aRangeMax = std::max(resultCoord, aRectMin);
   return resultCoord;
 }
 /**
  * This function takes a scrollable frame, a rect in the coordinate system
  * of the scrolled frame, and a desired percentage-based scroll
  * position and attempts to scroll the rect to that position in the
  * scrollport.
  *
  * This needs to work even if aRect has a width or height of zero.
  */
 static void ScrollToShowRect(nsIFrame*                aFrame,
                              nsIScrollableFrame*      aFrameAsScrollable,
                              const nsRect&            aRect,
                              nsIPresShell::ScrollAxis aVertical,
                              nsIPresShell::ScrollAxis aHorizontal,
                              uint32_t                 aFlags)
 {
   nsPoint scrollPt = aFrameAsScrollable->GetScrollPosition();
   nsRect visibleRect(scrollPt,
                      aFrameAsScrollable->GetScrollPositionClampingScrollPortSize());
   // If this is the root scroll frame, make sure to take into account the
   // content document fixed position margins. When set, these indicate that
   // chrome is obscuring the viewport.
   nsRect targetRect(aRect);
   nsIPresShell *presShell = aFrame->PresContext()->PresShell();
   if (aFrameAsScrollable == presShell->GetRootScrollFrameAsScrollable()) {
     targetRect.Inflate(presShell->GetContentDocumentFixedPositionMargins());
   }
   nsSize lineSize;
   // Don't call GetLineScrollAmount unless we actually need it. Not only
   // does this save time, but it's not safe to call GetLineScrollAmount
   // during reflow (because it depends on font size inflation and doesn't
   // use the in-reflow-safe font-size inflation path). If we did call it,
   // it would assert and possible give the wrong result.
   if (aVertical.mWhenToScroll == nsIPresShell::SCROLL_IF_NOT_VISIBLE ||
       aHorizontal.mWhenToScroll == nsIPresShell::SCROLL_IF_NOT_VISIBLE) {
     lineSize = aFrameAsScrollable->GetLineScrollAmount();
   }
   ScrollbarStyles ss = aFrameAsScrollable->GetScrollbarStyles();
   nsRect allowedRange(scrollPt, nsSize(0, 0));
   bool needToScroll = false;
   uint32_t directions = aFrameAsScrollable->GetPerceivedScrollingDirections();
   if (((aFlags & nsIPresShell::SCROLL_OVERFLOW_HIDDEN) ||
        ss.mVertical != NS_STYLE_OVERFLOW_HIDDEN) &&
       (!aVertical.mOnlyIfPerceivedScrollableDirection ||
        (directions & nsIScrollableFrame::VERTICAL))) {
     if (ComputeNeedToScroll(aVertical.mWhenToScroll,
                             lineSize.height,
                             targetRect.y,
                             targetRect.YMost(),
                             visibleRect.y,
                             visibleRect.YMost())) {
       nscoord maxHeight;
       scrollPt.y = ComputeWhereToScroll(aVertical.mWhereToScroll,
                                         scrollPt.y,
                                         targetRect.y,
                                         targetRect.YMost(),
                                         visibleRect.y,
                                         visibleRect.YMost(),
                                         &allowedRange.y, &maxHeight);
       allowedRange.height = maxHeight - allowedRange.y;
       needToScroll = true;
     }
   }
   if (((aFlags & nsIPresShell::SCROLL_OVERFLOW_HIDDEN) ||
        ss.mHorizontal != NS_STYLE_OVERFLOW_HIDDEN) &&
       (!aHorizontal.mOnlyIfPerceivedScrollableDirection ||
        (directions & nsIScrollableFrame::HORIZONTAL))) {
     if (ComputeNeedToScroll(aHorizontal.mWhenToScroll,
                             lineSize.width,
                             targetRect.x,
                             targetRect.XMost(),
                             visibleRect.x,
                             visibleRect.XMost())) {
       nscoord maxWidth;
       scrollPt.x = ComputeWhereToScroll(aHorizontal.mWhereToScroll,
                                         scrollPt.x,
                                         targetRect.x,
                                         targetRect.XMost(),
                                         visibleRect.x,
                                         visibleRect.XMost(),
                                         &allowedRange.x, &maxWidth);
       allowedRange.width = maxWidth - allowedRange.x;
       needToScroll = true;
     }
   }
   // If we don't need to scroll, then don't try since it might cancel
   // a current smooth scroll operation.
   if (needToScroll) {
     aFrameAsScrollable->ScrollTo(scrollPt, nsIScrollableFrame::INSTANT, &allowedRange);
   }
 }
 nsresult
 PresShell::ScrollContentIntoView(nsIContent*              aContent,
                                  nsIPresShell::ScrollAxis aVertical,
                                  nsIPresShell::ScrollAxis aHorizontal,
                                  uint32_t                 aFlags)
 {
   NS_ENSURE_TRUE(aContent, NS_ERROR_NULL_POINTER);
   nsCOMPtr<nsIDocument> currentDoc = aContent->GetCurrentDoc();
   NS_ENSURE_STATE(currentDoc);
   NS_ASSERTION(mDidInitialize, "should have done initial reflow by now");
   if (mContentToScrollTo) {
     mContentToScrollTo->DeleteProperty(nsGkAtoms::scrolling);
   }
   mContentToScrollTo = aContent;
   ScrollIntoViewData* data = new ScrollIntoViewData();
   data->mContentScrollVAxis = aVertical;
   data->mContentScrollHAxis = aHorizontal;
   data->mContentToScrollToFlags = aFlags;
   if (NS_FAILED(mContentToScrollTo->SetProperty(nsGkAtoms::scrolling, data,
                                                 nsINode::DeleteProperty<PresShell::ScrollIntoViewData>))) {
     mContentToScrollTo = nullptr;
   }
   // Flush layout and attempt to scroll in the process.
   currentDoc->SetNeedLayoutFlush();
   currentDoc->FlushPendingNotifications(Flush_InterruptibleLayout);
   // If mContentToScrollTo is non-null, that means we interrupted the reflow
   // (or suppressed it altogether because we're suppressing interruptible
   // flushes right now) and won't necessarily get the position correct, but do
   // a best-effort scroll here.  The other option would be to do this inside
   // FlushPendingNotifications, but I'm not sure the repeated scrolling that
   // could trigger if reflows keep getting interrupted would be more desirable
   // than a single best-effort scroll followed by one final scroll on the first
   // completed reflow.
   if (mContentToScrollTo) {
     DoScrollContentIntoView();
   }
   return NS_OK;
 }
 void
 PresShell::DoScrollContentIntoView()
 {
   NS_ASSERTION(mDidInitialize, "should have done initial reflow by now");
   nsIFrame* frame = mContentToScrollTo->GetPrimaryFrame();
   if (!frame) {
     mContentToScrollTo->DeleteProperty(nsGkAtoms::scrolling);
     mContentToScrollTo = nullptr;
     return;
   }
   if (frame->GetStateBits() & NS_FRAME_FIRST_REFLOW) {
     // The reflow flush before this scroll got interrupted, and this frame's
     // coords and size are all zero, and it has no content showing anyway.
     // Don't bother scrolling to it.  We'll try again when we finish up layout.
     return;
   }
   // Make sure we skip 'frame' ... if it's scrollable, we should use its
   // scrollable ancestor as the container.
   nsIFrame* container =
     nsLayoutUtils::GetClosestFrameOfType(frame->GetParent(), nsGkAtoms::scrollFrame);
   if (!container) {
     // nothing can be scrolled
     return;
   }
   ScrollIntoViewData* data = static_cast<ScrollIntoViewData*>(
     mContentToScrollTo->GetProperty(nsGkAtoms::scrolling));
   if (MOZ_UNLIKELY(!data)) {
     mContentToScrollTo = nullptr;
     return;
   }
   // This is a two-step process.
   // Step 1: Find the bounds of the rect we want to scroll into view.  For
   //         example, for an inline frame we may want to scroll in the whole
   //         line, or we may want to scroll multiple lines into view.
   // Step 2: Walk container frame and its ancestors and scroll them
   //         appropriately.
   // frameBounds is relative to container. We're assuming
   // that scrollframes don't split so every continuation of frame will
   // be a descendant of container. (Things would still mostly work
   // even if that assumption was false.)
   nsRect frameBounds;
   bool haveRect = false;
   bool useWholeLineHeightForInlines =
     data->mContentScrollVAxis.mWhenToScroll != nsIPresShell::SCROLL_IF_NOT_FULLY_VISIBLE;
   // Reuse the same line iterator across calls to AccumulateFrameBounds.  We set
   // it every time we detect a new block (stored in prevBlock).
   nsIFrame* prevBlock = nullptr;
   nsAutoLineIterator lines;
   // The last line we found a continuation on in |lines|.  We assume that later
   // continuations cannot come on earlier lines.
   int32_t curLine = 0;
   do {
     AccumulateFrameBounds(container, frame, useWholeLineHeightForInlines,
                           frameBounds, haveRect, prevBlock, lines, curLine);
   } while ((frame = frame->GetNextContinuation()));
   ScrollFrameRectIntoView(container, frameBounds, data->mContentScrollVAxis,
                           data->mContentScrollHAxis,
                           data->mContentToScrollToFlags);
 }
 bool
 PresShell::ScrollFrameRectIntoView(nsIFrame*                aFrame,
                                    const nsRect&            aRect,
                                    nsIPresShell::ScrollAxis aVertical,
                                    nsIPresShell::ScrollAxis aHorizontal,
                                    uint32_t                 aFlags)
 {
   bool didScroll = false;
   // This function needs to work even if rect has a width or height of 0.
   nsRect rect = aRect;
   nsIFrame* container = aFrame;
   // Walk up the frame hierarchy scrolling the rect into view and
   // keeping rect relative to container
   do {
     nsIScrollableFrame* sf = do_QueryFrame(container);
     if (sf) {
       nsPoint oldPosition = sf->GetScrollPosition();
       nsRect targetRect = rect;
       if (container->StyleDisplay()->mOverflowClipBox ==
             NS_STYLE_OVERFLOW_CLIP_BOX_CONTENT_BOX) {
         nsMargin padding = container->GetUsedPadding();
         targetRect.Inflate(padding);
       }
       ScrollToShowRect(container, sf, targetRect - sf->GetScrolledFrame()->GetPosition(),
                        aVertical, aHorizontal, aFlags);
       nsPoint newPosition = sf->GetScrollPosition();
       // If the scroll position increased, that means our content moved up,
       // so our rect's offset should decrease
       rect += oldPosition - newPosition;
       if (oldPosition != newPosition) {
         didScroll = true;
       }
       // only scroll one container when this flag is set
       if (aFlags & nsIPresShell::SCROLL_FIRST_ANCESTOR_ONLY) {
         break;
       }
     }
     nsIFrame* parent;
     if (container->IsTransformed()) {
       container->GetTransformMatrix(nullptr, &parent);
       rect = nsLayoutUtils::TransformFrameRectToAncestor(container, rect, parent);
     } else {
       rect += container->GetPosition();
       parent = container->GetParent();
     }
     if (!parent && !(aFlags & nsIPresShell::SCROLL_NO_PARENT_FRAMES)) {
       nsPoint extraOffset(0,0);
       parent = nsLayoutUtils::GetCrossDocParentFrame(container, &extraOffset);
       if (parent) {
         int32_t APD = container->PresContext()->AppUnitsPerDevPixel();
         int32_t parentAPD = parent->PresContext()->AppUnitsPerDevPixel();
         rect = rect.ConvertAppUnitsRoundOut(APD, parentAPD);
         rect += extraOffset;
       }
     }
     container = parent;
   } while (container);
   return didScroll;
 }
 nsRectVisibility
 PresShell::GetRectVisibility(nsIFrame* aFrame,
                              const nsRect &aRect,
                              nscoord aMinTwips) const
 {
   NS_ASSERTION(aFrame->PresContext() == GetPresContext(),
                "prescontext mismatch?");
   nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
   NS_ASSERTION(rootFrame,
                "How can someone have a frame for this presshell when there's no root?");
   nsIScrollableFrame* sf = GetRootScrollFrameAsScrollable();
   nsRect scrollPortRect;
   if (sf) {
     scrollPortRect = sf->GetScrollPortRect();
     nsIFrame* f = do_QueryFrame(sf);
     scrollPortRect += f->GetOffsetTo(rootFrame);
   } else {
     scrollPortRect = nsRect(nsPoint(0,0), rootFrame->GetSize());
   }
   nsRect r = aRect + aFrame->GetOffsetTo(rootFrame);
   // If aRect is entirely visible then we don't need to ensure that
   // at least aMinTwips of it is visible
   if (scrollPortRect.Contains(r))
     return nsRectVisibility_kVisible;
   nsRect insetRect = scrollPortRect;
   insetRect.Deflate(aMinTwips, aMinTwips);
   if (r.YMost() <= insetRect.y)
     return nsRectVisibility_kAboveViewport;
   if (r.y >= insetRect.YMost())
     return nsRectVisibility_kBelowViewport;
   if (r.XMost() <= insetRect.x)
     return nsRectVisibility_kLeftOfViewport;
   if (r.x >= insetRect.XMost())
     return nsRectVisibility_kRightOfViewport;
   return nsRectVisibility_kVisible;
 }
 class PaintTimerCallBack MOZ_FINAL : public nsITimerCallback
 {
 public:
   PaintTimerCallBack(PresShell* aShell) : mShell(aShell) {}
   NS_DECL_ISUPPORTS
   NS_IMETHODIMP Notify(nsITimer* aTimer) MOZ_FINAL
   {
     mShell->SetNextPaintCompressed();
     mShell->AddInvalidateHiddenPresShellObserver(mShell->GetPresContext()->RefreshDriver());
     mShell->ScheduleViewManagerFlush();
     return NS_OK;
   }
 private:
   PresShell* mShell;
 };
 NS_IMPL_ISUPPORTS(PaintTimerCallBack, nsITimerCallback)
 void
 PresShell::ScheduleViewManagerFlush(PaintType aType)
 {
   if (aType == PAINT_DELAYED_COMPRESS) {
     // Delay paint for 1 second.
     static const uint32_t kPaintDelayPeriod = 1000;
     if (!mDelayedPaintTimer) {
       mDelayedPaintTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
       nsRefPtr<PaintTimerCallBack> cb = new PaintTimerCallBack(this);
       mDelayedPaintTimer->InitWithCallback(cb, kPaintDelayPeriod, nsITimer::TYPE_ONE_SHOT);
     }
     return;
   }
   nsPresContext* presContext = GetPresContext();
   if (presContext) {
     presContext->RefreshDriver()->ScheduleViewManagerFlush();
   }
   if (mDocument) {
     mDocument->SetNeedLayoutFlush();
   }
 }
 void
 PresShell::DispatchSynthMouseMove(WidgetGUIEvent* aEvent,
                                   bool aFlushOnHoverChange)
 {
   RestyleManager* restyleManager = mPresContext->RestyleManager();
   uint32_t hoverGenerationBefore = restyleManager->GetHoverGeneration();
   nsEventStatus status;
   nsView* targetView = nsView::GetViewFor(aEvent->widget);
   if (!targetView)
     return;
   targetView->GetViewManager()->DispatchEvent(aEvent, targetView, &status);
   if (MOZ_UNLIKELY(mIsDestroying)) {
     return;
   }
   if (aFlushOnHoverChange &&
       hoverGenerationBefore != restyleManager->GetHoverGeneration()) {
     // Flush so that the resulting reflow happens now so that our caller
     // can suppress any synthesized mouse moves caused by that reflow.
     FlushPendingNotifications(Flush_Layout);
   }
 }
 void
 PresShell::ClearMouseCaptureOnView(nsView* aView)
 {
   if (gCaptureInfo.mContent) {
     if (aView) {
       // if a view was specified, ensure that the captured content is within
       // this view.
       nsIFrame* frame = gCaptureInfo.mContent->GetPrimaryFrame();
       if (frame) {
         nsView* view = frame->GetClosestView();
         // if there is no view, capturing won't be handled any more, so
         // just release the capture.
         if (view) {
           do {
             if (view == aView) {
               NS_RELEASE(gCaptureInfo.mContent);
               // the view containing the captured content likely disappeared so
               // disable capture for now.
               gCaptureInfo.mAllowed = false;
               break;
             }
             view = view->GetParent();
           } while (view);
           // return if the view wasn't found
           return;
         }
       }
     }
     NS_RELEASE(gCaptureInfo.mContent);
   }
   // disable mouse capture until the next mousedown as a dialog has opened
   // or a drag has started. Otherwise, someone could start capture during
   // the modal dialog or drag.
   gCaptureInfo.mAllowed = false;
 }
 void
 nsIPresShell::ClearMouseCapture(nsIFrame* aFrame)
 {
   if (!gCaptureInfo.mContent) {
     gCaptureInfo.mAllowed = false;
     return;
   }
   // null frame argument means clear the capture
   if (!aFrame) {
     NS_RELEASE(gCaptureInfo.mContent);
     gCaptureInfo.mAllowed = false;
     return;
   }
   nsIFrame* capturingFrame = gCaptureInfo.mContent->GetPrimaryFrame();
   if (!capturingFrame) {
     NS_RELEASE(gCaptureInfo.mContent);
     gCaptureInfo.mAllowed = false;
     return;
   }
   if (nsLayoutUtils::IsAncestorFrameCrossDoc(aFrame, capturingFrame)) {
     NS_RELEASE(gCaptureInfo.mContent);
     gCaptureInfo.mAllowed = false;
   }
 }
 nsresult
 PresShell::CaptureHistoryState(nsILayoutHistoryState** aState)
 {
   NS_PRECONDITION(nullptr != aState, "null state pointer");
   // We actually have to mess with the docshell here, since we want to
   // store the state back in it.
   // XXXbz this isn't really right, since this is being called in the
   // content viewer's Hide() method...  by that point the docshell's
   // state could be wrong.  We should sort out a better ownership
   // model for the layout history state.
   nsCOMPtr<nsIDocShell> docShell(mPresContext->GetDocShell());
   if (!docShell)
     return NS_ERROR_FAILURE;
   nsCOMPtr<nsILayoutHistoryState> historyState;
   docShell->GetLayoutHistoryState(getter_AddRefs(historyState));
   if (!historyState) {
     // Create the document state object
     historyState = NS_NewLayoutHistoryState();
     docShell->SetLayoutHistoryState(historyState);
   }
   *aState = historyState;
   NS_IF_ADDREF(*aState);
   // Capture frame state for the entire frame hierarchy
   nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
   if (!rootFrame) return NS_OK;
   mFrameConstructor->CaptureFrameState(rootFrame, historyState);
   return NS_OK;
 }
 void
 PresShell::UnsuppressAndInvalidate()
 {
   // Note: We ignore the EnsureVisible check for resource documents, because
   // they won't have a docshell, so they'll always fail EnsureVisible.
   if ((!mDocument->IsResourceDoc() && !mPresContext->EnsureVisible()) ||
       mHaveShutDown) {
     // No point; we're about to be torn down anyway.
     return;
   }
   if (!mDocument->IsResourceDoc()) {
     // Notify observers that a new page is about to be drawn. Execute this
     // as soon as it is safe to run JS, which is guaranteed to be before we
     // go back to the event loop and actually draw the page.
     nsContentUtils::AddScriptRunner(new nsBeforeFirstPaintDispatcher(mDocument));
   }
   mPaintingSuppressed = false;
   nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
   if (rootFrame) {
     // let's assume that outline on a root frame is not supported
     rootFrame->InvalidateFrame();
     if (mCaretEnabled && mCaret) {
       mCaret->CheckCaretDrawingState();
     }
   }
   // now that painting is unsuppressed, focus may be set on the document
   nsPIDOMWindow *win = mDocument->GetWindow();
   if (win)
     win->SetReadyForFocus();
   if (!mHaveShutDown) {
     SynthesizeMouseMove(false);
     ScheduleImageVisibilityUpdate();
   }
 }
 void
 PresShell::UnsuppressPainting()
 {
   if (mPaintSuppressionTimer) {
     mPaintSuppressionTimer->Cancel();
     mPaintSuppressionTimer = nullptr;
   }
   if (mIsDocumentGone || !mPaintingSuppressed)
     return;
   // If we have reflows pending, just wait until we process
   // the reflows and get all the frames where we want them
   // before actually unlocking the painting.  Otherwise
   // go ahead and unlock now.
   if (!mDirtyRoots.IsEmpty())
     mShouldUnsuppressPainting = true;
   else
     UnsuppressAndInvalidate();
 }
 // Post a request to handle an arbitrary callback after reflow has finished.
 nsresult
 PresShell::PostReflowCallback(nsIReflowCallback* aCallback)
 {
   void* result = AllocateMisc(sizeof(nsCallbackEventRequest));
   nsCallbackEventRequest* request = (nsCallbackEventRequest*)result;
   request->callback = aCallback;
   request->next = nullptr;
   if (mLastCallbackEventRequest) {
     mLastCallbackEventRequest = mLastCallbackEventRequest->next = request;
   } else {
     mFirstCallbackEventRequest = request;
     mLastCallbackEventRequest = request;
   }
   return NS_OK;
 }
 void
 PresShell::CancelReflowCallback(nsIReflowCallback* aCallback)
 {
    nsCallbackEventRequest* before = nullptr;
    nsCallbackEventRequest* node = mFirstCallbackEventRequest;
    while(node)
    {
       nsIReflowCallback* callback = node->callback;
       if (callback == aCallback)
       {
         nsCallbackEventRequest* toFree = node;
         if (node == mFirstCallbackEventRequest) {
           node = node->next;
           mFirstCallbackEventRequest = node;
           NS_ASSERTION(before == nullptr, "impossible");
         } else {
           node = node->next;
           before->next = node;
         }
         if (toFree == mLastCallbackEventRequest) {
           mLastCallbackEventRequest = before;
         }
         FreeMisc(sizeof(nsCallbackEventRequest), toFree);
       } else {
         before = node;
         node = node->next;
       }
    }
 }
 void
 PresShell::CancelPostedReflowCallbacks()
 {
   while (mFirstCallbackEventRequest) {
     nsCallbackEventRequest* node = mFirstCallbackEventRequest;
     mFirstCallbackEventRequest = node->next;
     if (!mFirstCallbackEventRequest) {
       mLastCallbackEventRequest = nullptr;
     }
     nsIReflowCallback* callback = node->callback;
     FreeMisc(sizeof(nsCallbackEventRequest), node);
     if (callback) {
       callback->ReflowCallbackCanceled();
     }
   }
 }
 void
 PresShell::HandlePostedReflowCallbacks(bool aInterruptible)
 {
    bool shouldFlush = false;
    while (mFirstCallbackEventRequest) {
      nsCallbackEventRequest* node = mFirstCallbackEventRequest;
      mFirstCallbackEventRequest = node->next;
      if (!mFirstCallbackEventRequest) {
        mLastCallbackEventRequest = nullptr;
      }
      nsIReflowCallback* callback = node->callback;
      FreeMisc(sizeof(nsCallbackEventRequest), node);
      if (callback) {
        if (callback->ReflowFinished()) {
          shouldFlush = true;
        }
      }
    }
    mozFlushType flushType =
      aInterruptible ? Flush_InterruptibleLayout : Flush_Layout;
    if (shouldFlush && !mIsDestroying) {
      FlushPendingNotifications(flushType);
    }
 }
 bool
 PresShell::IsSafeToFlush() const
 {
   // Not safe if we are reflowing or in the middle of frame construction
   bool isSafeToFlush = !mIsReflowing &&
                          !mChangeNestCount;
   if (isSafeToFlush) {
     // Not safe if we are painting
     nsViewManager* viewManager = GetViewManager();
     if (viewManager) {
       bool isPainting = false;
       viewManager->IsPainting(isPainting);
       if (isPainting) {
         isSafeToFlush = false;
       }
     }
   }
   return isSafeToFlush;
 }
 void
 PresShell::FlushPendingNotifications(mozFlushType aType)
 {
   // by default, flush animations if aType >= Flush_Style
   mozilla::ChangesToFlush flush(aType, aType >= Flush_Style);
   FlushPendingNotifications(flush);
 }
 void
 PresShell::FlushPendingNotifications(mozilla::ChangesToFlush aFlush)
 {
   if (mIsZombie) {
     return;
   }
   /**
    * VERY IMPORTANT: If you add some sort of new flushing to this
    * method, make sure to add the relevant SetNeedLayoutFlush or
    * SetNeedStyleFlush calls on the document.
    */
   mozFlushType flushType = aFlush.mFlushType;
 #ifdef MOZ_ENABLE_PROFILER_SPS
   static const char flushTypeNames[][20] = {
     "Content",
     "ContentAndNotify",
     "Style",
     "InterruptibleLayout",
     "Layout",
     "Display"
   };
   // Make sure that we don't miss things added to mozFlushType!
   MOZ_ASSERT(static_cast<uint32_t>(flushType) <= ArrayLength(flushTypeNames));
   PROFILER_LABEL_PRINTF("layout", "Flush", "(Flush_%s)",
                       flushTypeNames[flushType - 1]);
 #endif
 #ifdef ACCESSIBILITY
 #ifdef DEBUG
   nsAccessibilityService* accService = GetAccService();
   if (accService) {
     NS_ASSERTION(!accService->IsProcessingRefreshDriverNotification(),
                  "Flush during accessible tree update!");
   }
 #endif
 #endif
   NS_ASSERTION(flushType >= Flush_Frames, "Why did we get called?");
   bool isSafeToFlush = IsSafeToFlush();
   // If layout could possibly trigger scripts, then it's only safe to flush if
   // it's safe to run script.
   bool hasHadScriptObject;
   if (mDocument->GetScriptHandlingObject(hasHadScriptObject) ||
       hasHadScriptObject) {
     isSafeToFlush = isSafeToFlush && nsContentUtils::IsSafeToRunScript();
   }
   NS_ASSERTION(!isSafeToFlush || mViewManager, "Must have view manager");
   // Make sure the view manager stays alive.
   nsRefPtr<nsViewManager> viewManagerDeathGrip = mViewManager;
   if (isSafeToFlush && mViewManager) {
     // Processing pending notifications can kill us, and some callers only
     // hold weak refs when calling FlushPendingNotifications().  :(
     nsCOMPtr<nsIPresShell> kungFuDeathGrip(this);
     if (mResizeEvent.IsPending()) {
       FireResizeEvent();
       if (mIsDestroying) {
         return;
       }
     }
     // We need to make sure external resource documents are flushed too (for
     // example, svg filters that reference a filter in an external document
     // need the frames in the external document to be constructed for the
     // filter to work). We only need external resources to be flushed when the
     // main document is flushing >= Flush_Frames, so we flush external
     // resources here instead of nsDocument::FlushPendingNotifications.
     mDocument->FlushExternalResources(flushType);
     // Force flushing of any pending content notifications that might have
     // queued up while our event was pending.  That will ensure that we don't
     // construct frames for content right now that's still waiting to be
     // notified on,
     mDocument->FlushPendingNotifications(Flush_ContentAndNotify);
     // Process pending restyles, since any flush of the presshell wants
     // up-to-date style data.
     if (!mIsDestroying) {
       mViewManager->FlushDelayedResize(false);
       mPresContext->FlushPendingMediaFeatureValuesChanged();
       // Flush any pending update of the user font set, since that could
       // cause style changes (for updating ex/ch units, and to cause a
       // reflow).
       mPresContext->FlushUserFontSet();
       // Flush any requested SMIL samples.
       if (mDocument->HasAnimationController()) {
         mDocument->GetAnimationController()->FlushResampleRequests();
       }
       if (aFlush.mFlushAnimations &&
           nsLayoutUtils::AreAsyncAnimationsEnabled() &&
           !mPresContext->StyleUpdateForAllAnimationsIsUpToDate()) {
         mPresContext->AnimationManager()->
           FlushAnimations(CommonAnimationManager::Cannot_Throttle);
         mPresContext->TransitionManager()->
           FlushTransitions(CommonAnimationManager::Cannot_Throttle);
         mPresContext->TickLastStyleUpdateForAllAnimations();
       }
       // The FlushResampleRequests() above flushed style changes.
       if (!mIsDestroying) {
         nsAutoScriptBlocker scriptBlocker;
         mPresContext->RestyleManager()->ProcessPendingRestyles();
       }
     }
     // Dispatch any 'animationstart' events those (or earlier) restyles
     // queued up.
     if (!mIsDestroying) {
       mPresContext->AnimationManager()->DispatchEvents();
     }
     // Process whatever XBL constructors those restyles queued up.  This
     // ensures that onload doesn't fire too early and that we won't do extra
     // reflows after those constructors run.
     if (!mIsDestroying) {
       mDocument->BindingManager()->ProcessAttachedQueue();
     }
     // Now those constructors or events might have posted restyle
     // events.  At the same time, we still need up-to-date style data.
     // In particular, reflow depends on style being completely up to
     // date.  If it's not, then style context reparenting, which can
     // happen during reflow, might suddenly pick up the new rules and
     // we'll end up with frames whose style doesn't match the frame
     // type.
     if (!mIsDestroying) {
       nsAutoScriptBlocker scriptBlocker;
       mPresContext->RestyleManager()->ProcessPendingRestyles();
     }
     // There might be more pending constructors now, but we're not going to
     // worry about them.  They can't be triggered during reflow, so we should
     // be good.
     if (flushType >= (mSuppressInterruptibleReflows ? Flush_Layout : Flush_InterruptibleLayout) &&
         !mIsDestroying) {
       mFrameConstructor->RecalcQuotesAndCounters();
       mViewManager->FlushDelayedResize(true);
       if (ProcessReflowCommands(flushType < Flush_Layout) && mContentToScrollTo) {
         // We didn't get interrupted.  Go ahead and scroll to our content
         DoScrollContentIntoView();
         if (mContentToScrollTo) {
           mContentToScrollTo->DeleteProperty(nsGkAtoms::scrolling);
           mContentToScrollTo = nullptr;
         }
       }
     } else if (!mIsDestroying && mSuppressInterruptibleReflows &&
                flushType == Flush_InterruptibleLayout) {
       // We suppressed this flush, but the document thinks it doesn't
       // need to flush anymore.  Let it know what's really going on.
       mDocument->SetNeedLayoutFlush();
     }
     if (flushType >= Flush_Layout) {
       if (!mIsDestroying) {
         mViewManager->UpdateWidgetGeometry();
       }
     }
   }
 }
 void
 PresShell::CharacterDataWillChange(nsIDocument *aDocument,
                                    nsIContent*  aContent,
                                    CharacterDataChangeInfo* aInfo)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected CharacterDataChanged");
   NS_PRECONDITION(aDocument == mDocument, "Unexpected aDocument");
   if (mCaret) {
     // Invalidate the caret's current location before we call into the frame
     // constructor. It is important to do this now, and not wait until the
     // resulting reflow, because this call causes continuation frames of the
     // text frame the caret is in to forget what part of the content they
     // refer to, making it hard for them to return the correct continuation
     // frame to the caret.
     //
     // It's also important to do this before the content actually changes, since
     // in bidi text the caret needs to look at the content to determine its
     // position and shape.
     mCaret->InvalidateOutsideCaret();
   }
 }
 void
 PresShell::CharacterDataChanged(nsIDocument *aDocument,
                                 nsIContent*  aContent,
                                 CharacterDataChangeInfo* aInfo)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected CharacterDataChanged");
   NS_PRECONDITION(aDocument == mDocument, "Unexpected aDocument");
   nsAutoCauseReflowNotifier crNotifier(this);
   // Call this here so it only happens for real content mutations and
   // not cases when the frame constructor calls its own methods to force
   // frame reconstruction.
   nsIContent *container = aContent->GetParent();
   uint32_t selectorFlags =
     container ? (container->GetFlags() & NODE_ALL_SELECTOR_FLAGS) : 0;
   if (selectorFlags != 0 && !aContent->IsRootOfAnonymousSubtree()) {
     Element* element = container->AsElement();
     if (aInfo->mAppend && !aContent->GetNextSibling())
       mPresContext->RestyleManager()->RestyleForAppend(element, aContent);
     else
       mPresContext->RestyleManager()->RestyleForInsertOrChange(element, aContent);
   }
   mFrameConstructor->CharacterDataChanged(aContent, aInfo);
   VERIFY_STYLE_TREE;
 }
 void
 PresShell::ContentStateChanged(nsIDocument* aDocument,
                                nsIContent* aContent,
                                EventStates aStateMask)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected ContentStateChanged");
   NS_PRECONDITION(aDocument == mDocument, "Unexpected aDocument");
   if (mDidInitialize) {
     nsAutoCauseReflowNotifier crNotifier(this);
     mPresContext->RestyleManager()->ContentStateChanged(aContent, aStateMask);
     VERIFY_STYLE_TREE;
   }
 }
 void
 PresShell::DocumentStatesChanged(nsIDocument* aDocument,
                                  EventStates aStateMask)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected DocumentStatesChanged");
   NS_PRECONDITION(aDocument == mDocument, "Unexpected aDocument");
   if (mDidInitialize &&
       mStyleSet->HasDocumentStateDependentStyle(mPresContext,
                                                 mDocument->GetRootElement(),
                                                 aStateMask)) {
     mPresContext->RestyleManager()->PostRestyleEvent(mDocument->GetRootElement(),
                                                      eRestyle_Subtree,
                                                      NS_STYLE_HINT_NONE);
     VERIFY_STYLE_TREE;
   }
   if (aStateMask.HasState(NS_DOCUMENT_STATE_WINDOW_INACTIVE)) {
     nsIFrame* root = mFrameConstructor->GetRootFrame();
     if (root) {
       root->SchedulePaint();
     }
   }
 }
 void
 PresShell::AttributeWillChange(nsIDocument* aDocument,
                                Element*     aElement,
                                int32_t      aNameSpaceID,
                                nsIAtom*     aAttribute,
                                int32_t      aModType)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected AttributeWillChange");
   NS_PRECONDITION(aDocument == mDocument, "Unexpected aDocument");
   // XXXwaterson it might be more elegant to wait until after the
   // initial reflow to begin observing the document. That would
   // squelch any other inappropriate notifications as well.
   if (mDidInitialize) {
     nsAutoCauseReflowNotifier crNotifier(this);
     mPresContext->RestyleManager()->AttributeWillChange(aElement, aNameSpaceID,
                                                         aAttribute, aModType);
     VERIFY_STYLE_TREE;
   }
 }
 void
 PresShell::AttributeChanged(nsIDocument* aDocument,
                             Element*     aElement,
                             int32_t      aNameSpaceID,
                             nsIAtom*     aAttribute,
                             int32_t      aModType)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected AttributeChanged");
   NS_PRECONDITION(aDocument == mDocument, "Unexpected aDocument");
   // XXXwaterson it might be more elegant to wait until after the
   // initial reflow to begin observing the document. That would
   // squelch any other inappropriate notifications as well.
   if (mDidInitialize) {
     nsAutoCauseReflowNotifier crNotifier(this);
     mPresContext->RestyleManager()->AttributeChanged(aElement, aNameSpaceID,
                                                      aAttribute, aModType);
     VERIFY_STYLE_TREE;
   }
 }
 void
 PresShell::ContentAppended(nsIDocument *aDocument,
                            nsIContent* aContainer,
                            nsIContent* aFirstNewContent,
                            int32_t     aNewIndexInContainer)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected ContentAppended");
   NS_PRECONDITION(aDocument == mDocument, "Unexpected aDocument");
   NS_PRECONDITION(aContainer, "must have container");
   if (!mDidInitialize) {
     return;
   }
   nsAutoCauseReflowNotifier crNotifier(this);
   // Call this here so it only happens for real content mutations and
   // not cases when the frame constructor calls its own methods to force
   // frame reconstruction.
   if (aContainer->IsElement()) {
     // Ensure the container is an element before trying to restyle
     // because it can be the case that the container is a ShadowRoot
     // which is a document fragment.
     mPresContext->RestyleManager()->
       RestyleForAppend(aContainer->AsElement(), aFirstNewContent);
   }
   mFrameConstructor->ContentAppended(aContainer, aFirstNewContent, true);
   if (static_cast<nsINode*>(aContainer) == static_cast<nsINode*>(aDocument) &&
       aFirstNewContent->NodeType() == nsIDOMNode::DOCUMENT_TYPE_NODE) {
     NotifyFontSizeInflationEnabledIsDirty();
   }
   VERIFY_STYLE_TREE;
 }
 void
 PresShell::ContentInserted(nsIDocument* aDocument,
                            nsIContent*  aContainer,
                            nsIContent*  aChild,
                            int32_t      aIndexInContainer)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected ContentInserted");
   NS_PRECONDITION(aDocument == mDocument, "Unexpected aDocument");
   if (!mDidInitialize) {
     return;
   }
   nsAutoCauseReflowNotifier crNotifier(this);
   // Call this here so it only happens for real content mutations and
   // not cases when the frame constructor calls its own methods to force
   // frame reconstruction.
   if (aContainer && aContainer->IsElement()) {
     // Ensure the container is an element before trying to restyle
     // because it can be the case that the container is a ShadowRoot
     // which is a document fragment.
     mPresContext->RestyleManager()->
       RestyleForInsertOrChange(aContainer->AsElement(), aChild);
   }
   mFrameConstructor->ContentInserted(aContainer, aChild, nullptr, true);
   if (((!aContainer && aDocument) ||
       (static_cast<nsINode*>(aContainer) == static_cast<nsINode*>(aDocument))) &&
       aChild->NodeType() == nsIDOMNode::DOCUMENT_TYPE_NODE) {
     NotifyFontSizeInflationEnabledIsDirty();
   }
   VERIFY_STYLE_TREE;
 }
 void
 PresShell::ContentRemoved(nsIDocument *aDocument,
                           nsIContent* aContainer,
                           nsIContent* aChild,
                           int32_t     aIndexInContainer,
                           nsIContent* aPreviousSibling)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected ContentRemoved");
   NS_PRECONDITION(aDocument == mDocument, "Unexpected aDocument");
   // Make sure that the caret doesn't leave a turd where the child used to be.
   if (mCaret) {
     mCaret->InvalidateOutsideCaret();
   }
   // Notify the ESM that the content has been removed, so that
   // it can clean up any state related to the content.
   // XXX_jwir3: There is no null check for aDocument necessary, since, even
   //            though by nsIMutationObserver, aDocument could be null, the
   //            precondition check that mDocument == aDocument ensures that
   //            aDocument will not be null (since mDocument can't be null unless
   //            we're still intializing).
   mPresContext->EventStateManager()->ContentRemoved(aDocument, aChild);
   nsAutoCauseReflowNotifier crNotifier(this);
   // Call this here so it only happens for real content mutations and
   // not cases when the frame constructor calls its own methods to force
   // frame reconstruction.
   nsIContent* oldNextSibling;
   if (aContainer) {
     oldNextSibling = aContainer->GetChildAt(aIndexInContainer);
   } else {
     oldNextSibling = nullptr;
   }
   if (aContainer && aContainer->IsElement()) {
     mPresContext->RestyleManager()->
       RestyleForRemove(aContainer->AsElement(), aChild, oldNextSibling);
   }
   bool didReconstruct;
   mFrameConstructor->ContentRemoved(aContainer, aChild, oldNextSibling,
                                     nsCSSFrameConstructor::REMOVE_CONTENT,
                                     &didReconstruct);
   if (((aContainer &&
       static_cast<nsINode*>(aContainer) == static_cast<nsINode*>(aDocument)) ||
       aDocument) && aChild->NodeType() == nsIDOMNode::DOCUMENT_TYPE_NODE) {
     NotifyFontSizeInflationEnabledIsDirty();
   }
   VERIFY_STYLE_TREE;
 }
 nsresult
 PresShell::ReconstructFrames(void)
 {
   NS_PRECONDITION(!mFrameConstructor->GetRootFrame() || mDidInitialize,
                   "Must not have root frame before initial reflow");
   if (!mDidInitialize) {
     // Nothing to do here
     return NS_OK;
   }
   nsCOMPtr<nsIPresShell> kungFuDeathGrip(this);
   // Have to make sure that the content notifications are flushed before we
   // start messing with the frame model; otherwise we can get content doubling.
   mDocument->FlushPendingNotifications(Flush_ContentAndNotify);
   nsAutoCauseReflowNotifier crNotifier(this);
   mFrameConstructor->BeginUpdate();
   nsresult rv = mFrameConstructor->ReconstructDocElementHierarchy();
   VERIFY_STYLE_TREE;
   mFrameConstructor->EndUpdate();
   return rv;
 }
 void
 nsIPresShell::ReconstructStyleDataInternal()
 {
   nsAutoTArray<nsRefPtr<mozilla::dom::Element>,1> scopeRoots;
   mChangedScopeStyleRoots.SwapElements(scopeRoots);
   if (mStylesHaveChanged) {
     // If we need to restyle everything, no need to restyle individual
     // scoped style roots.
     scopeRoots.Clear();
   }
   mStylesHaveChanged = false;
   if (mIsDestroying) {
     // We don't want to mess with restyles at this point
     return;
   }
   if (mPresContext) {
     mPresContext->RebuildUserFontSet();
   }
   Element* root = mDocument->GetRootElement();
   if (!mDidInitialize) {
     // Nothing to do here, since we have no frames yet
     return;
   }
   if (!root) {
     // No content to restyle
     return;
   }
   RestyleManager* restyleManager = mPresContext->RestyleManager();
   if (scopeRoots.IsEmpty()) {
     // If scopeRoots is empty, we know that mStylesHaveChanged was true at
     // the beginning of this function, and that we need to restyle the whole
     // document.
     restyleManager->PostRestyleEvent(root, eRestyle_Subtree,
                                      NS_STYLE_HINT_NONE);
   } else {
     for (uint32_t i = 0; i < scopeRoots.Length(); i++) {
       Element* scopeRoot = scopeRoots[i];
       restyleManager->PostRestyleEvent(scopeRoot, eRestyle_Subtree,
                                        NS_STYLE_HINT_NONE);
     }
   }
 }
 void
 nsIPresShell::ReconstructStyleDataExternal()
 {
   ReconstructStyleDataInternal();
 }
 void
 PresShell::RecordStyleSheetChange(nsIStyleSheet* aStyleSheet)
 {
   if (mStylesHaveChanged)
     return;
   nsRefPtr<nsCSSStyleSheet> cssStyleSheet = do_QueryObject(aStyleSheet);
   if (cssStyleSheet) {
     Element* scopeElement = cssStyleSheet->GetScopeElement();
     if (scopeElement) {
       mChangedScopeStyleRoots.AppendElement(scopeElement);
       return;
     }
   }
   mStylesHaveChanged = true;
 }
 void
 PresShell::StyleSheetAdded(nsIDocument *aDocument,
                            nsIStyleSheet* aStyleSheet,
                            bool aDocumentSheet)
 {
   // We only care when enabled sheets are added
   NS_PRECONDITION(aStyleSheet, "Must have a style sheet!");
   if (aStyleSheet->IsApplicable() && aStyleSheet->HasRules()) {
     RecordStyleSheetChange(aStyleSheet);
   }
 }
 void
 PresShell::StyleSheetRemoved(nsIDocument *aDocument,
                              nsIStyleSheet* aStyleSheet,
                              bool aDocumentSheet)
 {
   // We only care when enabled sheets are removed
   NS_PRECONDITION(aStyleSheet, "Must have a style sheet!");
   if (aStyleSheet->IsApplicable() && aStyleSheet->HasRules()) {
     RecordStyleSheetChange(aStyleSheet);
   }
 }
 void
 PresShell::StyleSheetApplicableStateChanged(nsIDocument *aDocument,
                                             nsIStyleSheet* aStyleSheet,
                                             bool aApplicable)
 {
   if (aStyleSheet->HasRules()) {
     RecordStyleSheetChange(aStyleSheet);
   }
 }
 void
 PresShell::StyleRuleChanged(nsIDocument *aDocument,
                             nsIStyleSheet* aStyleSheet,
                             nsIStyleRule* aOldStyleRule,
                             nsIStyleRule* aNewStyleRule)
 {
   RecordStyleSheetChange(aStyleSheet);
 }
 void
 PresShell::StyleRuleAdded(nsIDocument *aDocument,
                           nsIStyleSheet* aStyleSheet,
                           nsIStyleRule* aStyleRule)
 {
   RecordStyleSheetChange(aStyleSheet);
 }
 void
 PresShell::StyleRuleRemoved(nsIDocument *aDocument,
                             nsIStyleSheet* aStyleSheet,
                             nsIStyleRule* aStyleRule)
 {
   RecordStyleSheetChange(aStyleSheet);
 }
 nsIFrame*
 PresShell::GetRealPrimaryFrameFor(nsIContent* aContent) const
 {
   if (aContent->GetDocument() != GetDocument()) {
     return nullptr;
   }
   nsIFrame *primaryFrame = aContent->GetPrimaryFrame();
   if (!primaryFrame)
     return nullptr;
   return nsPlaceholderFrame::GetRealFrameFor(primaryFrame);
 }
 nsIFrame*
 PresShell::GetPlaceholderFrameFor(nsIFrame* aFrame) const
 {
   return mFrameConstructor->GetPlaceholderFrameFor(aFrame);
 }
 nsresult
 PresShell::RenderDocument(const nsRect& aRect, uint32_t aFlags,
                           nscolor aBackgroundColor,
                           gfxContext* aThebesContext)
 {
   NS_ENSURE_TRUE(!(aFlags & RENDER_IS_UNTRUSTED), NS_ERROR_NOT_IMPLEMENTED);
   nsRootPresContext* rootPresContext = mPresContext->GetRootPresContext();
   if (rootPresContext) {
     rootPresContext->FlushWillPaintObservers();
     if (mIsDestroying)
       return NS_OK;
   }
   nsAutoScriptBlocker blockScripts;
   // Set up the rectangle as the path in aThebesContext
   gfxRect r(0, 0,
             nsPresContext::AppUnitsToFloatCSSPixels(aRect.width),
             nsPresContext::AppUnitsToFloatCSSPixels(aRect.height));
   aThebesContext->NewPath();
 #ifdef MOZ_GFX_OPTIMIZE_MOBILE
   aThebesContext->Rectangle(r, true);
 #else
   aThebesContext->Rectangle(r);
 #endif
   nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
   if (!rootFrame) {
     // Nothing to paint, just fill the rect
     aThebesContext->SetColor(gfxRGBA(aBackgroundColor));
     aThebesContext->Fill();
     return NS_OK;
   }
   gfxContextAutoSaveRestore save(aThebesContext);
   gfxContext::GraphicsOperator oldOperator = aThebesContext->CurrentOperator();
   if (oldOperator == gfxContext::OPERATOR_OVER) {
     // Clip to the destination rectangle before we push the group,
     // to limit the size of the temporary surface
     aThebesContext->Clip();
   }
   // we want the window to be composited as a single image using
   // whatever operator was set; set OPERATOR_OVER here, which is
   // either already the case, or overrides the operator in a group.
   // the original operator will be present when we PopGroup.
   // we can avoid using a temporary surface if we're using OPERATOR_OVER
   bool needsGroup = oldOperator != gfxContext::OPERATOR_OVER;
   if (needsGroup) {
     aThebesContext->PushGroup(NS_GET_A(aBackgroundColor) == 0xff ?
                               gfxContentType::COLOR :
                               gfxContentType::COLOR_ALPHA);
     aThebesContext->Save();
     if (oldOperator != gfxContext::OPERATOR_OVER) {
       // Clip now while we paint to the temporary surface. For
       // non-source-bounded operators (e.g., SOURCE), we need to do clip
       // here after we've pushed the group, so that eventually popping
       // the group and painting it will be able to clear the entire
       // destination surface.
       aThebesContext->Clip();
       aThebesContext->SetOperator(gfxContext::OPERATOR_OVER);
     }
   }
   aThebesContext->Translate(gfxPoint(-nsPresContext::AppUnitsToFloatCSSPixels(aRect.x),
                                      -nsPresContext::AppUnitsToFloatCSSPixels(aRect.y)));
   nsDeviceContext* devCtx = mPresContext->DeviceContext();
   gfxFloat scale = gfxFloat(devCtx->AppUnitsPerDevPixel())/nsPresContext::AppUnitsPerCSSPixel();
   aThebesContext->Scale(scale, scale);
   // Since canvas APIs use floats to set up their matrices, we may have
   // some slight inaccuracy here. Adjust matrix components that are
   // integers up to the accuracy of floats to be those integers.
   aThebesContext->NudgeCurrentMatrixToIntegers();
   AutoSaveRestoreRenderingState _(this);
   nsRefPtr<nsRenderingContext> rc = new nsRenderingContext();
   rc->Init(devCtx, aThebesContext);
   bool wouldFlushRetainedLayers = false;
   uint32_t flags = nsLayoutUtils::PAINT_IGNORE_SUPPRESSION;
   if (aThebesContext->CurrentMatrix().HasNonIntegerTranslation()) {
     flags |= nsLayoutUtils::PAINT_IN_TRANSFORM;
   }
   if (!(aFlags & RENDER_ASYNC_DECODE_IMAGES)) {
     flags |= nsLayoutUtils::PAINT_SYNC_DECODE_IMAGES;
   }
   if (aFlags & RENDER_USE_WIDGET_LAYERS) {
     // We only support using widget layers on display root's with widgets.
     nsView* view = rootFrame->GetView();
     if (view && view->GetWidget() &&
         nsLayoutUtils::GetDisplayRootFrame(rootFrame) == rootFrame) {
       flags |= nsLayoutUtils::PAINT_WIDGET_LAYERS;
     }
   }
   if (!(aFlags & RENDER_CARET)) {
     wouldFlushRetainedLayers = true;
     flags |= nsLayoutUtils::PAINT_HIDE_CARET;
   }
   if (aFlags & RENDER_IGNORE_VIEWPORT_SCROLLING) {
     wouldFlushRetainedLayers = !IgnoringViewportScrolling();
     mRenderFlags = ChangeFlag(mRenderFlags, true, STATE_IGNORING_VIEWPORT_SCROLLING);
   }
   if (aFlags & RENDER_DRAWWINDOW_NOT_FLUSHING) {
     mRenderFlags = ChangeFlag(mRenderFlags, true, STATE_DRAWWINDOW_NOT_FLUSHING);
   }
   if (aFlags & RENDER_DOCUMENT_RELATIVE) {
     // XXX be smarter about this ... drawWindow might want a rect
     // that's "pretty close" to what our retained layer tree covers.
     // In that case, it wouldn't disturb normal rendering too much,
     // and we should allow it.
     wouldFlushRetainedLayers = true;
     flags |= nsLayoutUtils::PAINT_DOCUMENT_RELATIVE;
   }
   // Don't let drawWindow blow away our retained layer tree
   if ((flags & nsLayoutUtils::PAINT_WIDGET_LAYERS) && wouldFlushRetainedLayers) {
     flags &= ~nsLayoutUtils::PAINT_WIDGET_LAYERS;
   }
   nsLayoutUtils::PaintFrame(rc, rootFrame, nsRegion(aRect),
                             aBackgroundColor, flags);
   // if we had to use a group, paint it to the destination now
   if (needsGroup) {
     aThebesContext->Restore();
     aThebesContext->PopGroupToSource();
     aThebesContext->Paint();
   }
   return NS_OK;
 }
 /*
  * Clip the display list aList to a range. Returns the clipped
  * rectangle surrounding the range.
  */
 nsRect
 PresShell::ClipListToRange(nsDisplayListBuilder *aBuilder,
                            nsDisplayList* aList,
                            nsRange* aRange)
 {
   // iterate though the display items and add up the bounding boxes of each.
   // This will allow the total area of the frames within the range to be
   // determined. To do this, remove an item from the bottom of the list, check
   // whether it should be part of the range, and if so, append it to the top
   // of the temporary list tmpList. If the item is a text frame at the end of
   // the selection range, clip it to the portion of the text frame that is
   // part of the selection. Then, append the wrapper to the top of the list.
   // Otherwise, just delete the item and don't append it.
   nsRect surfaceRect;
   nsDisplayList tmpList;
   nsDisplayItem* i;
   while ((i = aList->RemoveBottom())) {
     // itemToInsert indiciates the item that should be inserted into the
     // temporary list. If null, no item should be inserted.
     nsDisplayItem* itemToInsert = nullptr;
     nsIFrame* frame = i->Frame();
     nsIContent* content = frame->GetContent();
     if (content) {
       bool atStart = (content == aRange->GetStartParent());
       bool atEnd = (content == aRange->GetEndParent());
       if ((atStart || atEnd) && frame->GetType() == nsGkAtoms::textFrame) {
         int32_t frameStartOffset, frameEndOffset;
         frame->GetOffsets(frameStartOffset, frameEndOffset);
         int32_t hilightStart =
           atStart ? std::max(aRange->StartOffset(), frameStartOffset) : frameStartOffset;
         int32_t hilightEnd =
           atEnd ? std::min(aRange->EndOffset(), frameEndOffset) : frameEndOffset;
         if (hilightStart < hilightEnd) {
           // determine the location of the start and end edges of the range.
           nsPoint startPoint, endPoint;
           frame->GetPointFromOffset(hilightStart, &startPoint);
           frame->GetPointFromOffset(hilightEnd, &endPoint);
           // the clip rectangle is determined by taking the the start and
           // end points of the range, offset from the reference frame.
           // Because of rtl, the end point may be to the left of the
           // start point, so x is set to the lowest value
           nsRect textRect(aBuilder->ToReferenceFrame(frame), frame->GetSize());
           nscoord x = std::min(startPoint.x, endPoint.x);
           textRect.x += x;
           textRect.width = std::max(startPoint.x, endPoint.x) - x;
           surfaceRect.UnionRect(surfaceRect, textRect);
           DisplayItemClip newClip;
           newClip.SetTo(textRect);
           newClip.IntersectWith(i->GetClip());
           i->SetClip(aBuilder, newClip);
           itemToInsert = i;
         }
       }
       // Don't try to descend into subdocuments.
       // If this ever changes we'd need to add handling for subdocuments with
       // different zoom levels.
       else if (content->GetCurrentDoc() ==
                  aRange->GetStartParent()->GetCurrentDoc()) {
         // if the node is within the range, append it to the temporary list
         bool before, after;
         nsresult rv =
           nsRange::CompareNodeToRange(content, aRange, &before, &after);
         if (NS_SUCCEEDED(rv) && !before && !after) {
           itemToInsert = i;
           bool snap;
           surfaceRect.UnionRect(surfaceRect, i->GetBounds(aBuilder, &snap));
         }
       }
     }
     // insert the item into the list if necessary. If the item has a child
     // list, insert that as well
     nsDisplayList* sublist = i->GetSameCoordinateSystemChildren();
     if (itemToInsert || sublist) {
       tmpList.AppendToTop(itemToInsert ? itemToInsert : i);
       // if the item is a list, iterate over it as well
       if (sublist)
         surfaceRect.UnionRect(surfaceRect,
           ClipListToRange(aBuilder, sublist, aRange));
     }
     else {
       // otherwise, just delete the item and don't readd it to the list
       i->~nsDisplayItem();
     }
   }
   // now add all the items back onto the original list again
   aList->AppendToTop(&tmpList);
   return surfaceRect;
 }
 #ifdef DEBUG
 #include <stdio.h>
 static bool gDumpRangePaintList = false;
 #endif
 RangePaintInfo*
 PresShell::CreateRangePaintInfo(nsIDOMRange* aRange,
                                 nsRect& aSurfaceRect,
                                 bool aForPrimarySelection)
 {
   RangePaintInfo* info = nullptr;
   nsRange* range = static_cast<nsRange*>(aRange);
   nsIFrame* ancestorFrame;
   nsIFrame* rootFrame = GetRootFrame();
   // If the start or end of the range is the document, just use the root
   // frame, otherwise get the common ancestor of the two endpoints of the
   // range.
   nsINode* startParent = range->GetStartParent();
   nsINode* endParent = range->GetEndParent();
   nsIDocument* doc = startParent->GetCurrentDoc();
   if (startParent == doc || endParent == doc) {
     ancestorFrame = rootFrame;
   }
   else {
     nsINode* ancestor = nsContentUtils::GetCommonAncestor(startParent, endParent);
     NS_ASSERTION(!ancestor || ancestor->IsNodeOfType(nsINode::eCONTENT),
                  "common ancestor is not content");
     if (!ancestor || !ancestor->IsNodeOfType(nsINode::eCONTENT))
       return nullptr;
     nsIContent* ancestorContent = static_cast<nsIContent*>(ancestor);
     ancestorFrame = ancestorContent->GetPrimaryFrame();
     // use the nearest ancestor frame that includes all continuations as the
     // root for building the display list
     while (ancestorFrame &&
            nsLayoutUtils::GetNextContinuationOrIBSplitSibling(ancestorFrame))
       ancestorFrame = ancestorFrame->GetParent();
   }
   if (!ancestorFrame)
     return nullptr;
   info = new RangePaintInfo(range, ancestorFrame);
   nsRect ancestorRect = ancestorFrame->GetVisualOverflowRect();
   // get a display list containing the range
   info->mBuilder.SetIncludeAllOutOfFlows();
   if (aForPrimarySelection) {
     info->mBuilder.SetSelectedFramesOnly();
   }
   info->mBuilder.EnterPresShell(ancestorFrame, ancestorRect);
   ancestorFrame->BuildDisplayListForStackingContext(&info->mBuilder,
                                                     ancestorRect, &info->mList);
 #ifdef DEBUG
   if (gDumpRangePaintList) {
     fprintf(stderr, "CreateRangePaintInfo --- before ClipListToRange:\n");
     nsFrame::PrintDisplayList(&(info->mBuilder), info->mList);
   }
 #endif
   nsRect rangeRect = ClipListToRange(&info->mBuilder, &info->mList, range);
   info->mBuilder.LeavePresShell(ancestorFrame, ancestorRect);
 #ifdef DEBUG
   if (gDumpRangePaintList) {
     fprintf(stderr, "CreateRangePaintInfo --- after ClipListToRange:\n");
     nsFrame::PrintDisplayList(&(info->mBuilder), info->mList);
   }
 #endif
   // determine the offset of the reference frame for the display list
   // to the root frame. This will allow the coordinates used when painting
   // to all be offset from the same point
   info->mRootOffset = ancestorFrame->GetOffsetTo(rootFrame);
   rangeRect.MoveBy(info->mRootOffset);
   aSurfaceRect.UnionRect(aSurfaceRect, rangeRect);
   return info;
 }
 TemporaryRef<SourceSurface>
 PresShell::PaintRangePaintInfo(nsTArray<nsAutoPtr<RangePaintInfo> >* aItems,
                                nsISelection* aSelection,
                                nsIntRegion* aRegion,
                                nsRect aArea,
                                nsIntPoint& aPoint,
                                nsIntRect* aScreenRect)
 {
   nsPresContext* pc = GetPresContext();
   if (!pc || aArea.width == 0 || aArea.height == 0)
     return nullptr;
   nsDeviceContext* deviceContext = pc->DeviceContext();
   // use the rectangle to create the surface
   nsIntRect pixelArea = aArea.ToOutsidePixels(pc->AppUnitsPerDevPixel());
   // if the area of the image is larger than the maximum area, scale it down
   float scale = 0.0;
   nsIntRect rootScreenRect =
     GetRootFrame()->GetScreenRectInAppUnits().ToNearestPixels(
       pc->AppUnitsPerDevPixel());
   // if the image is larger in one or both directions than half the size of
   // the available screen area, scale the image down to that size.
   nsRect maxSize;
   deviceContext->GetClientRect(maxSize);
   nscoord maxWidth = pc->AppUnitsToDevPixels(maxSize.width >> 1);
   nscoord maxHeight = pc->AppUnitsToDevPixels(maxSize.height >> 1);
   bool resize = (pixelArea.width > maxWidth || pixelArea.height > maxHeight);
   if (resize) {
     scale = 1.0;
     // divide the maximum size by the image size in both directions. Whichever
     // direction produces the smallest result determines how much should be
     // scaled.
     if (pixelArea.width > maxWidth)
       scale = std::min(scale, float(maxWidth) / pixelArea.width);
     if (pixelArea.height > maxHeight)
       scale = std::min(scale, float(maxHeight) / pixelArea.height);
     pixelArea.width = NSToIntFloor(float(pixelArea.width) * scale);
     pixelArea.height = NSToIntFloor(float(pixelArea.height) * scale);
     // adjust the screen position based on the rescaled size
     nscoord left = rootScreenRect.x + pixelArea.x;
     nscoord top = rootScreenRect.y + pixelArea.y;
     aScreenRect->x = NSToIntFloor(aPoint.x - float(aPoint.x - left) * scale);
     aScreenRect->y = NSToIntFloor(aPoint.y - float(aPoint.y - top) * scale);
   }
   else {
     // move aScreenRect to the position of the surface in screen coordinates
     aScreenRect->MoveTo(rootScreenRect.x + pixelArea.x, rootScreenRect.y + pixelArea.y);
   }
   aScreenRect->width = pixelArea.width;
   aScreenRect->height = pixelArea.height;
   RefPtr<DrawTarget> dt =
    gfxPlatform::GetPlatform()->CreateOffscreenContentDrawTarget(
                                  IntSize(pixelArea.width, pixelArea.height),
                                  SurfaceFormat::B8G8R8A8);
   if (!dt) {
     return nullptr;
   }
   nsRefPtr<gfxContext> ctx = new gfxContext(dt);
   nsRefPtr<nsRenderingContext> rc = new nsRenderingContext();
   rc->Init(deviceContext, ctx);
   if (aRegion) {
     // Convert aRegion from CSS pixels to dev pixels
     nsIntRegion region =
       aRegion->ToAppUnits(nsPresContext::AppUnitsPerCSSPixel())
         .ToOutsidePixels(pc->AppUnitsPerDevPixel());
     rc->SetClip(region);
   }
   if (resize)
     rc->Scale(scale, scale);
   // translate so that points are relative to the surface area
   rc->Translate(-aArea.TopLeft());
   // temporarily hide the selection so that text is drawn normally. If a
   // selection is being rendered, use that, otherwise use the presshell's
   // selection.
   nsRefPtr<nsFrameSelection> frameSelection;
   if (aSelection) {
     frameSelection = static_cast<Selection*>(aSelection)->GetFrameSelection();
   }
   else {
     frameSelection = FrameSelection();
   }
   int16_t oldDisplaySelection = frameSelection->GetDisplaySelection();
   frameSelection->SetDisplaySelection(nsISelectionController::SELECTION_HIDDEN);
   // next, paint each range in the selection
   int32_t count = aItems->Length();
   for (int32_t i = 0; i < count; i++) {
     RangePaintInfo* rangeInfo = (*aItems)[i];
     // the display lists paint relative to the offset from the reference
     // frame, so translate the rendering context
     nsRenderingContext::AutoPushTranslation
       translate(rc, rangeInfo->mRootOffset);
     aArea.MoveBy(-rangeInfo->mRootOffset.x, -rangeInfo->mRootOffset.y);
     nsRegion visible(aArea);
     rangeInfo->mList.ComputeVisibilityForRoot(&rangeInfo->mBuilder, &visible);
     rangeInfo->mList.PaintRoot(&rangeInfo->mBuilder, rc, nsDisplayList::PAINT_DEFAULT);
     aArea.MoveBy(rangeInfo->mRootOffset.x, rangeInfo->mRootOffset.y);
   }
   // restore the old selection display state
   frameSelection->SetDisplaySelection(oldDisplaySelection);
   return dt->Snapshot();
 }
 TemporaryRef<SourceSurface>
 PresShell::RenderNode(nsIDOMNode* aNode,
                       nsIntRegion* aRegion,
                       nsIntPoint& aPoint,
                       nsIntRect* aScreenRect)
 {
   // area will hold the size of the surface needed to draw the node, measured
   // from the root frame.
   nsRect area;
   nsTArray<nsAutoPtr<RangePaintInfo> > rangeItems;
   // nothing to draw if the node isn't in a document
   nsCOMPtr<nsINode> node = do_QueryInterface(aNode);
   if (!node->IsInDoc())
     return nullptr;
   nsRefPtr<nsRange> range = new nsRange(node);
   if (NS_FAILED(range->SelectNode(aNode)))
     return nullptr;
   RangePaintInfo* info = CreateRangePaintInfo(range, area, false);
   if (info && !rangeItems.AppendElement(info)) {
     delete info;
     return nullptr;
   }
   if (aRegion) {
     // combine the area with the supplied region
     nsIntRect rrectPixels = aRegion->GetBounds();
     nsRect rrect = rrectPixels.ToAppUnits(nsPresContext::AppUnitsPerCSSPixel());
     area.IntersectRect(area, rrect);
     nsPresContext* pc = GetPresContext();
     if (!pc)
       return nullptr;
     // move the region so that it is offset from the topleft corner of the surface
     aRegion->MoveBy(-pc->AppUnitsToDevPixels(area.x),
                     -pc->AppUnitsToDevPixels(area.y));
   }
   return PaintRangePaintInfo(&rangeItems, nullptr, aRegion, area, aPoint,
                              aScreenRect);
 }
 TemporaryRef<SourceSurface>
 PresShell::RenderSelection(nsISelection* aSelection,
                            nsIntPoint& aPoint,
                            nsIntRect* aScreenRect)
 {
   // area will hold the size of the surface needed to draw the selection,
   // measured from the root frame.
   nsRect area;
   nsTArray<nsAutoPtr<RangePaintInfo> > rangeItems;
   // iterate over each range and collect them into the rangeItems array.
   // This is done so that the size of selection can be determined so as
   // to allocate a surface area
   int32_t numRanges;
   aSelection->GetRangeCount(&numRanges);
   NS_ASSERTION(numRanges > 0, "RenderSelection called with no selection");
   for (int32_t r = 0; r < numRanges; r++)
   {
     nsCOMPtr<nsIDOMRange> range;
     aSelection->GetRangeAt(r, getter_AddRefs(range));
     RangePaintInfo* info = CreateRangePaintInfo(range, area, true);
     if (info && !rangeItems.AppendElement(info)) {
       delete info;
       return nullptr;
     }
   }
   return PaintRangePaintInfo(&rangeItems, aSelection, nullptr, area, aPoint,
                              aScreenRect);
 }
 void
 PresShell::AddPrintPreviewBackgroundItem(nsDisplayListBuilder& aBuilder,
                                          nsDisplayList&        aList,
                                          nsIFrame*             aFrame,
                                          const nsRect&         aBounds)
 {
   aList.AppendNewToBottom(new (&aBuilder)
     nsDisplaySolidColor(&aBuilder, aFrame, aBounds, NS_RGB(115, 115, 115)));
 }
 static bool
 AddCanvasBackgroundColor(const nsDisplayList& aList, nsIFrame* aCanvasFrame,
                          nscolor aColor)
 {
   for (nsDisplayItem* i = aList.GetBottom(); i; i = i->GetAbove()) {
     if (i->Frame() == aCanvasFrame &&
         i->GetType() == nsDisplayItem::TYPE_CANVAS_BACKGROUND_COLOR) {
       nsDisplayCanvasBackgroundColor* bg = static_cast<nsDisplayCanvasBackgroundColor*>(i);
       bg->SetExtraBackgroundColor(aColor);
       return true;
     }
     nsDisplayList* sublist = i->GetSameCoordinateSystemChildren();
     if (sublist && AddCanvasBackgroundColor(*sublist, aCanvasFrame, aColor))
       return true;
   }
   return false;
 }
 void
 PresShell::AddCanvasBackgroundColorItem(nsDisplayListBuilder& aBuilder,
                                         nsDisplayList&        aList,
                                         nsIFrame*             aFrame,
                                         const nsRect&         aBounds,
                                         nscolor               aBackstopColor,
                                         uint32_t              aFlags)
 {
   if (aBounds.IsEmpty()) {
     return;
   }
   // We don't want to add an item for the canvas background color if the frame
   // (sub)tree we are painting doesn't include any canvas frames. There isn't
   // an easy way to check this directly, but if we check if the root of the
   // (sub)tree we are painting is a canvas frame that should cover us in all
   // cases (it will usually be a viewport frame when we have a canvas frame in
   // the (sub)tree).
   if (!(aFlags & nsIPresShell::FORCE_DRAW) &&
       !nsCSSRendering::IsCanvasFrame(aFrame)) {
     return;
   }
   nscolor bgcolor = NS_ComposeColors(aBackstopColor, mCanvasBackgroundColor);
   if (NS_GET_A(bgcolor) == 0)
     return;
   // To make layers work better, we want to avoid having a big non-scrolled
   // color background behind a scrolled transparent background. Instead,
   // we'll try to move the color background into the scrolled content
   // by making nsDisplayCanvasBackground paint it.
   if (!aFrame->GetParent()) {
     nsIScrollableFrame* sf =
       aFrame->PresContext()->PresShell()->GetRootScrollFrameAsScrollable();
     if (sf) {
       nsCanvasFrame* canvasFrame = do_QueryFrame(sf->GetScrolledFrame());
       if (canvasFrame && canvasFrame->IsVisibleForPainting(&aBuilder)) {
         if (AddCanvasBackgroundColor(aList, canvasFrame, bgcolor))
           return;
       }
     }
   }
   aList.AppendNewToBottom(
     new (&aBuilder) nsDisplaySolidColor(&aBuilder, aFrame, aBounds, bgcolor));
 }
 static bool IsTransparentContainerElement(nsPresContext* aPresContext)
 {
   nsCOMPtr<nsIDocShellTreeItem> docShellItem = aPresContext->GetDocShell();
   nsCOMPtr<nsPIDOMWindow> pwin(do_GetInterface(docShellItem));
   if (!pwin)
     return false;
   nsCOMPtr<nsIContent> containerElement =
     do_QueryInterface(pwin->GetFrameElementInternal());
   return containerElement &&
          containerElement->HasAttr(kNameSpaceID_None, nsGkAtoms::transparent);
 }
 nscolor PresShell::GetDefaultBackgroundColorToDraw()
 {
   if (!mPresContext || !mPresContext->GetBackgroundColorDraw()) {
     return NS_RGB(255,255,255);
   }
   return mPresContext->DefaultBackgroundColor();
 }
 void PresShell::UpdateCanvasBackground()
 {
   // If we have a frame tree and it has style information that
   // specifies the background color of the canvas, update our local
   // cache of that color.
   nsIFrame* rootStyleFrame = FrameConstructor()->GetRootElementStyleFrame();
   if (rootStyleFrame) {
     nsStyleContext* bgStyle =
       nsCSSRendering::FindRootFrameBackground(rootStyleFrame);
     // XXX We should really be passing the canvasframe, not the root element
     // style frame but we don't have access to the canvasframe here. It isn't
     // a problem because only a few frames can return something other than true
     // and none of them would be a canvas frame or root element style frame.
     bool drawBackgroundImage;
     bool drawBackgroundColor;
     mCanvasBackgroundColor =
       nsCSSRendering::DetermineBackgroundColor(mPresContext, bgStyle,
                                                rootStyleFrame,
                                                drawBackgroundImage,
                                                drawBackgroundColor);
     if (GetPresContext()->IsCrossProcessRootContentDocument() &&
         !IsTransparentContainerElement(mPresContext)) {
       mCanvasBackgroundColor =
         NS_ComposeColors(GetDefaultBackgroundColorToDraw(), mCanvasBackgroundColor);
     }
   }
   // If the root element of the document (ie html) has style 'display: none'
   // then the document's background color does not get drawn; cache the
   // color we actually draw.
   if (!FrameConstructor()->GetRootElementFrame()) {
     mCanvasBackgroundColor = GetDefaultBackgroundColorToDraw();
   }
   if (XRE_GetProcessType() == GeckoProcessType_Content) {
     if (TabChild* tabChild = TabChild::GetFrom(this)) {
       tabChild->SetBackgroundColor(mCanvasBackgroundColor);
     }
   }
 }
 nscolor PresShell::ComputeBackstopColor(nsView* aDisplayRoot)
 {
   nsIWidget* widget = aDisplayRoot->GetWidget();
   if (widget && (widget->GetTransparencyMode() != eTransparencyOpaque ||
                  widget->WidgetPaintsBackground())) {
     // Within a transparent widget, so the backstop color must be
     // totally transparent.
     return NS_RGBA(0,0,0,0);
   }
   // Within an opaque widget (or no widget at all), so the backstop
   // color must be totally opaque. The user's default background
   // as reported by the prescontext is guaranteed to be opaque.
   return GetDefaultBackgroundColorToDraw();
 }
 struct PaintParams {
   nscolor mBackgroundColor;
 };
 LayerManager* PresShell::GetLayerManager()
 {
   NS_ASSERTION(mViewManager, "Should have view manager");
   nsView* rootView = mViewManager->GetRootView();
   if (rootView) {
     if (nsIWidget* widget = rootView->GetWidget()) {
       return widget->GetLayerManager();
     }
   }
   return nullptr;
 }
 void PresShell::SetIgnoreViewportScrolling(bool aIgnore)
 {
   if (IgnoringViewportScrolling() == aIgnore) {
     return;
   }
   RenderingState state(this);
   state.mRenderFlags = ChangeFlag(state.mRenderFlags, aIgnore,
                                   STATE_IGNORING_VIEWPORT_SCROLLING);
   SetRenderingState(state);
 }
 nsresult PresShell::SetResolution(float aXResolution, float aYResolution)
 {
   if (!(aXResolution > 0.0 && aYResolution > 0.0)) {
     return NS_ERROR_ILLEGAL_VALUE;
   }
   if (aXResolution == mXResolution && aYResolution == mYResolution) {
     return NS_OK;
   }
   RenderingState state(this);
   state.mXResolution = aXResolution;
   state.mYResolution = aYResolution;
   SetRenderingState(state);
   return NS_OK;
 }
 gfxSize PresShell::GetCumulativeResolution()
 {
   gfxSize resolution = GetResolution();
   nsPresContext* parentCtx = GetPresContext()->GetParentPresContext();
   if (parentCtx) {
     resolution = resolution * parentCtx->PresShell()->GetCumulativeResolution();
   }
   return resolution;
 }
 void PresShell::SetRenderingState(const RenderingState& aState)
 {
   if (mRenderFlags != aState.mRenderFlags) {
     // Rendering state changed in a way that forces us to flush any
     // retained layers we might already have.
     LayerManager* manager = GetLayerManager();
     if (manager) {
       FrameLayerBuilder::InvalidateAllLayers(manager);
     }
   }
   mRenderFlags = aState.mRenderFlags;
   mXResolution = aState.mXResolution;
   mYResolution = aState.mYResolution;
 }
 void PresShell::SynthesizeMouseMove(bool aFromScroll)
 {
   if (!sSynthMouseMove)
     return;
   if (mPaintingSuppressed || !mIsActive || !mPresContext) {
     return;
   }
   if (!mPresContext->IsRoot()) {
     nsIPresShell* rootPresShell = GetRootPresShell();
     if (rootPresShell) {
       rootPresShell->SynthesizeMouseMove(aFromScroll);
     }
     return;
   }
   if (mMouseLocation == nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE))
     return;
   if (!mSynthMouseMoveEvent.IsPending()) {
     nsRefPtr<nsSynthMouseMoveEvent> ev =
         new nsSynthMouseMoveEvent(this, aFromScroll);
     if (!GetPresContext()->RefreshDriver()->AddRefreshObserver(ev,
                                                                Flush_Display)) {
       NS_WARNING("failed to dispatch nsSynthMouseMoveEvent");
       return;
     }
     mSynthMouseMoveEvent = ev;
   }
 }
 /**
  * Find the first floating view with a widget in a postorder traversal of the
  * view tree that contains the point. Thus more deeply nested floating views
  * are preferred over their ancestors, and floating views earlier in the
  * view hierarchy (i.e., added later) are preferred over their siblings.
  * This is adequate for finding the "topmost" floating view under a point,
  * given that floating views don't supporting having a specific z-index.
  *
  * We cannot exit early when aPt is outside the view bounds, because floating
  * views aren't necessarily included in their parent's bounds, so this could
  * traverse the entire view hierarchy --- use carefully.
  */
 static nsView* FindFloatingViewContaining(nsView* aView, nsPoint aPt)
 {
   if (aView->GetVisibility() == nsViewVisibility_kHide)
     // No need to look into descendants.
     return nullptr;
   nsIFrame* frame = aView->GetFrame();
   if (frame) {
     if (!frame->IsVisibleConsideringAncestors(nsIFrame::VISIBILITY_CROSS_CHROME_CONTENT_BOUNDARY) ||
         !frame->PresContext()->PresShell()->IsActive()) {
       return nullptr;
     }
   }
   for (nsView* v = aView->GetFirstChild(); v; v = v->GetNextSibling()) {
     nsView* r = FindFloatingViewContaining(v, v->ConvertFromParentCoords(aPt));
     if (r)
       return r;
   }
   if (aView->GetFloating() && aView->HasWidget() &&
       aView->GetDimensions().Contains(aPt))
     return aView;
   return nullptr;
 }
 /*
  * This finds the first view containing the given point in a postorder
  * traversal of the view tree that contains the point, assuming that the
  * point is not in a floating view.  It assumes that only floating views
  * extend outside the bounds of their parents.
  *
  * This methods should only be called if FindFloatingViewContaining
  * returns null.
  */
 static nsView* FindViewContaining(nsView* aView, nsPoint aPt)
 {
   if (!aView->GetDimensions().Contains(aPt) ||
       aView->GetVisibility() == nsViewVisibility_kHide) {
     return nullptr;
   }
   nsIFrame* frame = aView->GetFrame();
   if (frame) {
     if (!frame->IsVisibleConsideringAncestors(nsIFrame::VISIBILITY_CROSS_CHROME_CONTENT_BOUNDARY) ||
         !frame->PresContext()->PresShell()->IsActive()) {
       return nullptr;
     }
   }
   for (nsView* v = aView->GetFirstChild(); v; v = v->GetNextSibling()) {
     nsView* r = FindViewContaining(v, v->ConvertFromParentCoords(aPt));
     if (r)
       return r;
   }
   return aView;
 }
 void
 PresShell::ProcessSynthMouseMoveEvent(bool aFromScroll)
 {
   // If drag session has started, we shouldn't synthesize mousemove event.
   nsCOMPtr<nsIDragSession> dragSession = nsContentUtils::GetDragSession();
   if (dragSession) {
     mSynthMouseMoveEvent.Forget();
     return;
   }
   // allow new event to be posted while handling this one only if the
   // source of the event is a scroll (to prevent infinite reflow loops)
   if (aFromScroll) {
     mSynthMouseMoveEvent.Forget();
   }
   nsView* rootView = mViewManager ? mViewManager->GetRootView() : nullptr;
   if (mMouseLocation == nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE) ||
       !rootView || !rootView->HasWidget() || !mPresContext) {
     mSynthMouseMoveEvent.Forget();
     return;
   }
   NS_ASSERTION(mPresContext->IsRoot(), "Only a root pres shell should be here");
   // Hold a ref to ourselves so DispatchEvent won't destroy us (since
   // we need to access members after we call DispatchEvent).
   nsCOMPtr<nsIPresShell> kungFuDeathGrip(this);
 #ifdef DEBUG_MOUSE_LOCATION
   printf("[ps=%p]synthesizing mouse move to (%d,%d)\n",
          this, mMouseLocation.x, mMouseLocation.y);
 #endif
   int32_t APD = mPresContext->AppUnitsPerDevPixel();
   // We need a widget to put in the event we are going to dispatch so we look
   // for a view that has a widget and the mouse location is over. We first look
   // for floating views, if there isn't one we use the root view. |view| holds
   // that view.
   nsView* view = nullptr;
   // The appunits per devpixel ratio of |view|.
   int32_t viewAPD;
   // refPoint will be mMouseLocation relative to the widget of |view|, the
   // widget we will put in the event we dispatch, in viewAPD appunits
   nsPoint refpoint(0, 0);
   // We always dispatch the event to the pres shell that contains the view that
   // the mouse is over. pointVM is the VM of that pres shell.
   nsViewManager *pointVM = nullptr;
   // This could be a bit slow (traverses entire view hierarchy)
   // but it's OK to do it once per synthetic mouse event
   view = FindFloatingViewContaining(rootView, mMouseLocation);
   if (!view) {
     view = rootView;
     nsView *pointView = FindViewContaining(rootView, mMouseLocation);
     // pointView can be null in situations related to mouse capture
     pointVM = (pointView ? pointView : view)->GetViewManager();
     refpoint = mMouseLocation + rootView->ViewToWidgetOffset();
     viewAPD = APD;
   } else {
     pointVM = view->GetViewManager();
     nsIFrame* frame = view->GetFrame();
     NS_ASSERTION(frame, "floating views can't be anonymous");
     viewAPD = frame->PresContext()->AppUnitsPerDevPixel();
     refpoint = mMouseLocation.ConvertAppUnits(APD, viewAPD);
     refpoint -= view->GetOffsetTo(rootView);
     refpoint += view->ViewToWidgetOffset();
   }
   NS_ASSERTION(view->GetWidget(), "view should have a widget here");
   WidgetMouseEvent event(true, NS_MOUSE_MOVE, view->GetWidget(),
                          WidgetMouseEvent::eSynthesized);
   event.refPoint = LayoutDeviceIntPoint::FromAppUnitsToNearest(refpoint, viewAPD);
   event.time = PR_IntervalNow();
   // XXX set event.modifiers ?
   // XXX mnakano I think that we should get the latest information from widget.
   nsCOMPtr<nsIPresShell> shell = pointVM->GetPresShell();
   if (shell) {
     shell->DispatchSynthMouseMove(&event, !aFromScroll);
   }
   if (!aFromScroll) {
     mSynthMouseMoveEvent.Forget();
   }
 }
 /* static */ void
 PresShell::MarkImagesInListVisible(const nsDisplayList& aList)
 {
   for (nsDisplayItem* item = aList.GetBottom(); item; item = item->GetAbove()) {
     nsDisplayList* sublist = item->GetChildren();
     if (sublist) {
       MarkImagesInListVisible(*sublist);
       continue;
     }
     nsIFrame* f = item->Frame();
     // We could check the type of the display item, only a handful can hold an
     // image loading content.
     // dont bother nscomptr here, it is wasteful
     nsCOMPtr<nsIImageLoadingContent> content(do_QueryInterface(f->GetContent()));
     if (content) {
       // use the presshell containing the image
       PresShell* presShell = static_cast<PresShell*>(f->PresContext()->PresShell());
       uint32_t count = presShell->mVisibleImages.Count();
       presShell->mVisibleImages.PutEntry(content);
       if (presShell->mVisibleImages.Count() > count) {
         // content was added to mVisibleImages, so we need to increment its visible count
         content->IncrementVisibleCount();
       }
     }
   }
 }
 static PLDHashOperator
 RemoveAndStore(nsRefPtrHashKey<nsIImageLoadingContent>* aEntry, void* userArg)
 {
   nsTArray< nsRefPtr<nsIImageLoadingContent> >* array =
     static_cast< nsTArray< nsRefPtr<nsIImageLoadingContent> >* >(userArg);
   array->AppendElement(aEntry->GetKey());
   return PL_DHASH_REMOVE;
 }
 void
 PresShell::RebuildImageVisibility(const nsDisplayList& aList)
 {
   MOZ_ASSERT(!mImageVisibilityVisited, "already visited?");
   mImageVisibilityVisited = true;
   // Remove the entries of the mVisibleImages hashtable and put them in the
   // beforeImageList array.
   nsTArray< nsRefPtr<nsIImageLoadingContent> > beforeImageList;
   beforeImageList.SetCapacity(mVisibleImages.Count());
   mVisibleImages.EnumerateEntries(RemoveAndStore, &beforeImageList);
   MarkImagesInListVisible(aList);
   for (uint32_t i = 0; i < beforeImageList.Length(); ++i) {
     beforeImageList[i]->DecrementVisibleCount();
   }
 }
 /* static */ void
 PresShell::ClearImageVisibilityVisited(nsView* aView, bool aClear)
 {
   nsViewManager* vm = aView->GetViewManager();
   if (aClear) {
     PresShell* presShell = static_cast<PresShell*>(vm->GetPresShell());
     if (!presShell->mImageVisibilityVisited) {
       presShell->ClearVisibleImagesList();
     }
     presShell->mImageVisibilityVisited = false;
   }
   for (nsView* v = aView->GetFirstChild(); v; v = v->GetNextSibling()) {
     ClearImageVisibilityVisited(v, v->GetViewManager() != vm);
   }
 }
 static PLDHashOperator
 DecrementVisibleCount(nsRefPtrHashKey<nsIImageLoadingContent>* aEntry, void* userArg)
 {
   aEntry->GetKey()->DecrementVisibleCount();
   return PL_DHASH_NEXT;
 }
 void
 PresShell::ClearVisibleImagesList()
 {
   mVisibleImages.EnumerateEntries(DecrementVisibleCount, nullptr);
   mVisibleImages.Clear();
 }
 void
 PresShell::UpdateImageVisibility()
 {
   MOZ_ASSERT(!mPresContext || mPresContext->IsRootContentDocument(),
     "updating image visibility on a non-root content document?");
   mUpdateImageVisibilityEvent.Revoke();
   if (mHaveShutDown || mIsDestroying) {
     return;
   }
   // call update on that frame
   nsIFrame* rootFrame = GetRootFrame();
   if (!rootFrame) {
     ClearVisibleImagesList();
     return;
   }
   // We could walk the frame tree directly and skip creating a display list for
   // better perf.
   nsRect updateRect(nsPoint(0, 0), rootFrame->GetSize());
   nsDisplayListBuilder builder(rootFrame, nsDisplayListBuilder::IMAGE_VISIBILITY, true);
   builder.IgnorePaintSuppression();
   builder.EnterPresShell(rootFrame, updateRect);
   nsDisplayList list;
   rootFrame->BuildDisplayListForStackingContext(&builder, updateRect, &list);
   builder.LeavePresShell(rootFrame, updateRect);
   RebuildImageVisibility(list);
   ClearImageVisibilityVisited(rootFrame->GetView(), true);
   list.DeleteAll();
 }
 bool
 PresShell::AssumeAllImagesVisible()
 {
   static bool sImageVisibilityEnabled = true;
   static bool sImageVisibilityEnabledForBrowserElementsOnly = false;
   static bool sImageVisibilityPrefCached = false;
   if (!sImageVisibilityPrefCached) {
     Preferences::AddBoolVarCache(&sImageVisibilityEnabled,
       "layout.imagevisibility.enabled", true);
     Preferences::AddBoolVarCache(&sImageVisibilityEnabledForBrowserElementsOnly,
       "layout.imagevisibility.enabled_for_browser_elements_only", false);
     sImageVisibilityPrefCached = true;
   }
   if ((!sImageVisibilityEnabled &&
        !sImageVisibilityEnabledForBrowserElementsOnly) ||
       !mPresContext || !mDocument) {
     return true;
   }
   // We assume all images are visible in print, print preview, chrome, xul, and
   // resource docs and don't keep track of them.
   if (mPresContext->Type() == nsPresContext::eContext_PrintPreview ||
       mPresContext->Type() == nsPresContext::eContext_Print ||
       mPresContext->IsChrome() ||
       mDocument->IsResourceDoc() ||
       mDocument->IsXUL()) {
     return true;
   }
   if (!sImageVisibilityEnabled &&
       sImageVisibilityEnabledForBrowserElementsOnly) {
     nsCOMPtr<nsIDocShell> docshell(mPresContext->GetDocShell());
     if (!docshell || !docshell->GetIsInBrowserElement()) {
       return true;
     }
   }
   return false;
 }
 void
 PresShell::ScheduleImageVisibilityUpdate()
 {
   if (AssumeAllImagesVisible())
     return;
   if (!mPresContext->IsRootContentDocument()) {
     nsPresContext* presContext = mPresContext->GetToplevelContentDocumentPresContext();
     if (!presContext)
       return;
     MOZ_ASSERT(presContext->IsRootContentDocument(),
       "Didn't get a root prescontext from GetToplevelContentDocumentPresContext?");
     presContext->PresShell()->ScheduleImageVisibilityUpdate();
     return;
   }
   if (mHaveShutDown || mIsDestroying)
     return;
   if (mUpdateImageVisibilityEvent.IsPending())
     return;
   nsRefPtr<nsRunnableMethod<PresShell> > ev =
     NS_NewRunnableMethod(this, &PresShell::UpdateImageVisibility);
   if (NS_SUCCEEDED(NS_DispatchToCurrentThread(ev))) {
     mUpdateImageVisibilityEvent = ev;
   }
 }
 void
 PresShell::EnsureImageInVisibleList(nsIImageLoadingContent* aImage)
 {
   if (AssumeAllImagesVisible()) {
     aImage->IncrementVisibleCount();
     return;
   }
 #ifdef DEBUG
   // if it has a frame make sure its in this presshell
   nsCOMPtr<nsIContent> content = do_QueryInterface(aImage);
   if (content) {
     PresShell* shell = static_cast<PresShell*>(content->OwnerDoc()->GetShell());
     MOZ_ASSERT(!shell || shell == this, "wrong shell");
   }
 #endif
   if (!mVisibleImages.Contains(aImage)) {
     mVisibleImages.PutEntry(aImage);
     aImage->IncrementVisibleCount();
   }
 }
 void
 PresShell::RemoveImageFromVisibleList(nsIImageLoadingContent* aImage)
 {
 #ifdef DEBUG
   // if it has a frame make sure its in this presshell
   nsCOMPtr<nsIContent> content = do_QueryInterface(aImage);
   if (content) {
     PresShell* shell = static_cast<PresShell*>(content->OwnerDoc()->GetShell());
     MOZ_ASSERT(!shell || shell == this, "wrong shell");
   }
 #endif
   if (AssumeAllImagesVisible()) {
     MOZ_ASSERT(mVisibleImages.Count() == 0, "shouldn't have any images in the table");
     return;
   }
   uint32_t count = mVisibleImages.Count();
   mVisibleImages.RemoveEntry(aImage);
   if (mVisibleImages.Count() < count) {
     // aImage was in the hashtable, so we need to decrement its visible count
     aImage->DecrementVisibleCount();
   }
 }
 class nsAutoNotifyDidPaint
 {
 public:
   nsAutoNotifyDidPaint(PresShell* aShell, uint32_t aFlags)
     : mShell(aShell), mFlags(aFlags)
   {
   }
   ~nsAutoNotifyDidPaint()
   {
     mShell->GetPresContext()->NotifyDidPaintForSubtree(mFlags);
   }
 private:
   PresShell* mShell;
   uint32_t mFlags;
 };
 class AutoUpdateHitRegion
 {
 public:
   AutoUpdateHitRegion(PresShell* aShell, nsIFrame* aFrame)
     : mShell(aShell), mFrame(aFrame)
   {
   }
   ~AutoUpdateHitRegion()
   {
     if (XRE_GetProcessType() != GeckoProcessType_Content ||
         !mFrame || !mShell) {
       return;
     }
     TabChild* tabChild = TabChild::GetFrom(mShell);
     if (!tabChild || !tabChild->GetUpdateHitRegion()) {
       return;
     }
     nsRegion region;
     nsDisplayListBuilder builder(mFrame,
                                  nsDisplayListBuilder::EVENT_DELIVERY,
                                  /* aBuildCert= */ false);
     nsDisplayList list;
     nsAutoTArray<nsIFrame*, 100> outFrames;
     nsDisplayItem::HitTestState hitTestState;
     nsRect bounds = mShell->GetPresContext()->GetVisibleArea();
     builder.EnterPresShell(mFrame, bounds);
     mFrame->BuildDisplayListForStackingContext(&builder, bounds, &list);
     builder.LeavePresShell(mFrame, bounds);
     list.HitTest(&builder, bounds, &hitTestState, &outFrames);
     list.DeleteAll();
     for (int32_t i = outFrames.Length() - 1; i >= 0; --i) {
       region.Or(region, nsLayoutUtils::TransformFrameRectToAncestor(
                   outFrames[i], nsRect(nsPoint(0, 0), outFrames[i]->GetSize()), mFrame));
     }
     tabChild->UpdateHitRegion(region);
   }
 private:
   PresShell* mShell;
   nsIFrame* mFrame;
 };
 void
 PresShell::RestyleShadowRoot(ShadowRoot* aShadowRoot)
 {
   // Mark the children of the ShadowRoot as style changed but not
   // the ShadowRoot itself because it is a document fragment and does not
   // have a frame.
   ExplicitChildIterator iterator(aShadowRoot);
   for (nsIContent* child = iterator.GetNextChild();
        child;
        child = iterator.GetNextChild()) {
     if (child->IsElement()) {
       mChangedScopeStyleRoots.AppendElement(child->AsElement());
     }
   }
 }
 void
 PresShell::Paint(nsView*        aViewToPaint,
                  const nsRegion& aDirtyRegion,
                  uint32_t        aFlags)
 {
   PROFILER_LABEL("Paint", "PresShell::Paint");
   NS_ASSERTION(!mIsDestroying, "painting a destroyed PresShell");
   NS_ASSERTION(aViewToPaint, "null view");
   MOZ_ASSERT(!mImageVisibilityVisited, "should have been cleared");
   if (!mIsActive || mIsZombie) {
     return;
   }
   nsPresContext* presContext = GetPresContext();
   AUTO_LAYOUT_PHASE_ENTRY_POINT(presContext, Paint);
   nsIFrame* frame = aViewToPaint->GetFrame();
   bool isRetainingManager;
   LayerManager* layerManager =
     aViewToPaint->GetWidget()->GetLayerManager(&isRetainingManager);
   NS_ASSERTION(layerManager, "Must be in paint event");
   bool shouldInvalidate = layerManager->NeedsWidgetInvalidation();
   nsAutoNotifyDidPaint notifyDidPaint(this, aFlags);
   AutoUpdateHitRegion updateHitRegion(this, frame);
   // Whether or not we should set first paint when painting is
   // suppressed is debatable. For now we'll do it because
   // B2G relies on first paint to configure the viewport and
   // we only want to do that when we have real content to paint.
   // See Bug 798245
   if (mIsFirstPaint && !mPaintingSuppressed) {
     layerManager->SetIsFirstPaint();
     mIsFirstPaint = false;
   }
   layerManager->BeginTransaction();
   if (frame && isRetainingManager) {
     // Try to do an empty transaction, if the frame tree does not
     // need to be updated. Do not try to do an empty transaction on
     // a non-retained layer manager (like the BasicLayerManager that
     // draws the window title bar on Mac), because a) it won't work
     // and b) below we don't want to clear NS_FRAME_UPDATE_LAYER_TREE,
     // that will cause us to forget to update the real layer manager!
     if (!(aFlags & PAINT_LAYERS)) {
       if (layerManager->EndEmptyTransaction()) {
         return;
       }
       NS_WARNING("Must complete empty transaction when compositing!");
     }
     if (!(frame->GetStateBits() & NS_FRAME_UPDATE_LAYER_TREE) &&
         !mNextPaintCompressed) {
       NotifySubDocInvalidationFunc computeInvalidFunc =
         presContext->MayHavePaintEventListenerInSubDocument() ? nsPresContext::NotifySubDocInvalidation : 0;
       bool computeInvalidRect = computeInvalidFunc ||
                                 (layerManager->GetBackendType() == LayersBackend::LAYERS_BASIC);
       nsAutoPtr<LayerProperties> props(computeInvalidRect ?
                                          LayerProperties::CloneFrom(layerManager->GetRoot()) :
                                          nullptr);
       if (layerManager->EndEmptyTransaction((aFlags & PAINT_COMPOSITE) ?
             LayerManager::END_DEFAULT : LayerManager::END_NO_COMPOSITE)) {
         nsIntRegion invalid;
         if (props) {
           invalid = props->ComputeDifferences(layerManager->GetRoot(), computeInvalidFunc);
         } else {
           LayerProperties::ClearInvalidations(layerManager->GetRoot());
         }
         if (props) {
           if (!invalid.IsEmpty()) {
             nsIntRect bounds = invalid.GetBounds();
             nsRect rect(presContext->DevPixelsToAppUnits(bounds.x),
                         presContext->DevPixelsToAppUnits(bounds.y),
                         presContext->DevPixelsToAppUnits(bounds.width),
                         presContext->DevPixelsToAppUnits(bounds.height));
             if (shouldInvalidate) {
               aViewToPaint->GetViewManager()->InvalidateViewNoSuppression(aViewToPaint, rect);
             }
             presContext->NotifyInvalidation(bounds, 0);
           }
         } else if (shouldInvalidate) {
           aViewToPaint->GetViewManager()->InvalidateView(aViewToPaint);
         }
         frame->UpdatePaintCountForPaintedPresShells();
         return;
       }
     }
     frame->RemoveStateBits(NS_FRAME_UPDATE_LAYER_TREE);
   }
   if (frame) {
     frame->ClearPresShellsFromLastPaint();
   }
   nscolor bgcolor = ComputeBackstopColor(aViewToPaint);
   uint32_t flags = nsLayoutUtils::PAINT_WIDGET_LAYERS | nsLayoutUtils::PAINT_EXISTING_TRANSACTION;
   if (!(aFlags & PAINT_COMPOSITE)) {
     flags |= nsLayoutUtils::PAINT_NO_COMPOSITE;
   }
   if (mNextPaintCompressed) {
     flags |= nsLayoutUtils::PAINT_COMPRESSED;
     mNextPaintCompressed = false;
   }
   if (frame) {
     // We can paint directly into the widget using its layer manager.
     nsLayoutUtils::PaintFrame(nullptr, frame, aDirtyRegion, bgcolor, flags);
     return;
   }
   nsRefPtr<ColorLayer> root = layerManager->CreateColorLayer();
   if (root) {
     nsPresContext* pc = GetPresContext();
     nsIntRect bounds =
       pc->GetVisibleArea().ToOutsidePixels(pc->AppUnitsPerDevPixel());
     bgcolor = NS_ComposeColors(bgcolor, mCanvasBackgroundColor);
     root->SetColor(bgcolor);
     root->SetVisibleRegion(bounds);
     layerManager->SetRoot(root);
   }
   layerManager->EndTransaction(nullptr, nullptr, (aFlags & PAINT_COMPOSITE) ?
     LayerManager::END_DEFAULT : LayerManager::END_NO_COMPOSITE);
 }
 // static
 void
 nsIPresShell::SetCapturingContent(nsIContent* aContent, uint8_t aFlags)
 {
   // If capture was set for pointer lock, don't unlock unless we are coming
   // out of pointer lock explicitly.
   if (!aContent && gCaptureInfo.mPointerLock &&
       !(aFlags & CAPTURE_POINTERLOCK)) {
     return;
   }
   NS_IF_RELEASE(gCaptureInfo.mContent);
   // only set capturing content if allowed or the CAPTURE_IGNOREALLOWED or
   // CAPTURE_POINTERLOCK flags are used.
   if ((aFlags & CAPTURE_IGNOREALLOWED) || gCaptureInfo.mAllowed ||
       (aFlags & CAPTURE_POINTERLOCK)) {
     if (aContent) {
       NS_ADDREF(gCaptureInfo.mContent = aContent);
     }
     // CAPTURE_POINTERLOCK is the same as CAPTURE_RETARGETTOELEMENT & CAPTURE_IGNOREALLOWED
     gCaptureInfo.mRetargetToElement = ((aFlags & CAPTURE_RETARGETTOELEMENT) != 0) ||
                                       ((aFlags & CAPTURE_POINTERLOCK) != 0);
     gCaptureInfo.mPreventDrag = (aFlags & CAPTURE_PREVENTDRAG) != 0;
     gCaptureInfo.mPointerLock = (aFlags & CAPTURE_POINTERLOCK) != 0;
   }
 }
 /* static */ void
 nsIPresShell::SetPointerCapturingContent(uint32_t aPointerId, nsIContent* aContent)
 {
   nsIContent* content = GetPointerCapturingContent(aPointerId);
   PointerInfo* pointerInfo = nullptr;
   if (!content && gActivePointersIds->Get(aPointerId, &pointerInfo) &&
       pointerInfo &&
       nsIDOMMouseEvent::MOZ_SOURCE_MOUSE == pointerInfo->mPointerType) {
     SetCapturingContent(aContent, CAPTURE_PREVENTDRAG);
   }
   if (content) {
     // Releasing capture for given pointer.
     gPointerCaptureList->Remove(aPointerId);
     DispatchGotOrLostPointerCaptureEvent(false, aPointerId, content);
     // Need to check the state because a lostpointercapture listener
     // may have called SetPointerCapture
     if (GetPointerCapturingContent(aPointerId)) {
       return;
     }
   }
   gPointerCaptureList->Put(aPointerId, aContent);
   DispatchGotOrLostPointerCaptureEvent(true, aPointerId, aContent);
 }
 /* static */ void
 nsIPresShell::ReleasePointerCapturingContent(uint32_t aPointerId, nsIContent* aContent)
 {
   if (gActivePointersIds->Get(aPointerId)) {
     SetCapturingContent(nullptr, CAPTURE_PREVENTDRAG);
   }
   // Releasing capture for given pointer.
   gPointerCaptureList->Remove(aPointerId);
   DispatchGotOrLostPointerCaptureEvent(false, aPointerId, aContent);
 }
 /* static */ nsIContent*
 nsIPresShell::GetPointerCapturingContent(uint32_t aPointerId)
 {
   return gPointerCaptureList->GetWeak(aPointerId);
 }
 /* static */ bool
 nsIPresShell::GetPointerInfo(uint32_t aPointerId, bool& aActiveState)
 {
   PointerInfo* pointerInfo = nullptr;
   if (gActivePointersIds->Get(aPointerId, &pointerInfo) && pointerInfo) {
     aActiveState = pointerInfo->mActiveState;
     return true;
   }
   return false;
 }
 void
 PresShell::UpdateActivePointerState(WidgetGUIEvent* aEvent)
 {
   switch (aEvent->message) {
   case NS_MOUSE_ENTER:
     // In this case we have to know information about available mouse pointers
     if (WidgetMouseEvent* mouseEvent = aEvent->AsMouseEvent()) {
       gActivePointersIds->Put(mouseEvent->pointerId, new PointerInfo(false, mouseEvent->inputSource));
     }
     break;
   case NS_POINTER_DOWN:
     // In this case we switch pointer to active state
     if (WidgetPointerEvent* pointerEvent = aEvent->AsPointerEvent()) {
       gActivePointersIds->Put(pointerEvent->pointerId, new PointerInfo(true, pointerEvent->inputSource));
     }
     break;
   case NS_POINTER_UP:
     // In this case we remove information about pointer or turn off active state
     if (WidgetPointerEvent* pointerEvent = aEvent->AsPointerEvent()) {
       if(pointerEvent->inputSource != nsIDOMMouseEvent::MOZ_SOURCE_TOUCH) {
         gActivePointersIds->Put(pointerEvent->pointerId, new PointerInfo(false, pointerEvent->inputSource));
       } else {
         gActivePointersIds->Remove(pointerEvent->pointerId);
       }
     }
     break;
   case NS_MOUSE_EXIT:
     // In this case we have to remove information about disappeared mouse pointers
     if (WidgetMouseEvent* mouseEvent = aEvent->AsMouseEvent()) {
       gActivePointersIds->Remove(mouseEvent->pointerId);
     }
     break;
   }
 }
 nsIContent*
 PresShell::GetCurrentEventContent()
 {
   if (mCurrentEventContent &&
       mCurrentEventContent->GetCurrentDoc() != mDocument) {
     mCurrentEventContent = nullptr;
     mCurrentEventFrame = nullptr;
   }
   return mCurrentEventContent;
 }
 nsIFrame*
 PresShell::GetCurrentEventFrame()
 {
   if (MOZ_UNLIKELY(mIsDestroying)) {
     return nullptr;
   }
   // GetCurrentEventContent() makes sure the content is still in the
   // same document that this pres shell belongs to. If not, then the
   // frame shouldn't get an event, nor should we even assume its safe
   // to try and find the frame.
   nsIContent* content = GetCurrentEventContent();
   if (!mCurrentEventFrame && content) {
     mCurrentEventFrame = content->GetPrimaryFrame();
     MOZ_ASSERT(!mCurrentEventFrame ||
                mCurrentEventFrame->PresContext()->GetPresShell() == this);
   }
   return mCurrentEventFrame;
 }
 nsIFrame*
 PresShell::GetEventTargetFrame()
 {
   return GetCurrentEventFrame();
 }
 already_AddRefed<nsIContent>
 PresShell::GetEventTargetContent(WidgetEvent* aEvent)
 {
   nsCOMPtr<nsIContent> content = GetCurrentEventContent();
   if (!content) {
     nsIFrame* currentEventFrame = GetCurrentEventFrame();
     if (currentEventFrame) {
       currentEventFrame->GetContentForEvent(aEvent, getter_AddRefs(content));
       NS_ASSERTION(!content || content->GetCurrentDoc() == mDocument,
                    "handing out content from a different doc");
     }
   }
   return content.forget();
 }
 void
 PresShell::PushCurrentEventInfo(nsIFrame* aFrame, nsIContent* aContent)
 {
   if (mCurrentEventFrame || mCurrentEventContent) {
     mCurrentEventFrameStack.InsertElementAt(0, mCurrentEventFrame);
     mCurrentEventContentStack.InsertObjectAt(mCurrentEventContent, 0);
   }
   mCurrentEventFrame = aFrame;
   mCurrentEventContent = aContent;
 }
 void
 PresShell::PopCurrentEventInfo()
 {
   mCurrentEventFrame = nullptr;
   mCurrentEventContent = nullptr;
   if (0 != mCurrentEventFrameStack.Length()) {
     mCurrentEventFrame = mCurrentEventFrameStack.ElementAt(0);
     mCurrentEventFrameStack.RemoveElementAt(0);
     mCurrentEventContent = mCurrentEventContentStack.ObjectAt(0);
     mCurrentEventContentStack.RemoveObjectAt(0);
     // Don't use it if it has moved to a different document.
     if (mCurrentEventContent &&
         mCurrentEventContent->GetCurrentDoc() != mDocument) {
       mCurrentEventContent = nullptr;
       mCurrentEventFrame = nullptr;
     }
   }
 }
 bool PresShell::InZombieDocument(nsIContent *aContent)
 {
   // If a content node points to a null document, or the document is not
   // attached to a window, then it is possibly in a zombie document,
   // about to be replaced by a newly loading document.
   // Such documents cannot handle DOM events.
   // It might actually be in a node not attached to any document,
   // in which case there is not parent presshell to retarget it to.
   nsIDocument *doc = aContent->GetDocument();
   return !doc || !doc->GetWindow();
 }
 already_AddRefed<nsPIDOMWindow>
 PresShell::GetRootWindow()
 {
   nsCOMPtr<nsPIDOMWindow> window =
     do_QueryInterface(mDocument->GetWindow());
   if (window) {
     nsCOMPtr<nsPIDOMWindow> rootWindow = window->GetPrivateRoot();
     NS_ASSERTION(rootWindow, "nsPIDOMWindow::GetPrivateRoot() returns NULL");
     return rootWindow.forget();
   }
   // If we don't have DOM window, we're zombie, we should find the root window
   // with our parent shell.
   nsCOMPtr<nsIPresShell> parent = GetParentPresShellForEventHandling();
   NS_ENSURE_TRUE(parent, nullptr);
   return parent->GetRootWindow();
 }
 already_AddRefed<nsIPresShell>
 PresShell::GetParentPresShellForEventHandling()
 {
   NS_ENSURE_TRUE(mPresContext, nullptr);
   // Now, find the parent pres shell and send the event there
   nsCOMPtr<nsIDocShellTreeItem> treeItem = mPresContext->GetDocShell();
   if (!treeItem) {
     treeItem = mForwardingContainer.get();
   }
   // Might have gone away, or never been around to start with
   NS_ENSURE_TRUE(treeItem, nullptr);
   nsCOMPtr<nsIDocShellTreeItem> parentTreeItem;
   treeItem->GetParent(getter_AddRefs(parentTreeItem));
   nsCOMPtr<nsIDocShell> parentDocShell = do_QueryInterface(parentTreeItem);
   NS_ENSURE_TRUE(parentDocShell && treeItem != parentTreeItem, nullptr);
   nsCOMPtr<nsIPresShell> parentPresShell = parentDocShell->GetPresShell();
   return parentPresShell.forget();
 }
 nsresult
 PresShell::RetargetEventToParent(WidgetGUIEvent* aEvent,
                                  nsEventStatus* aEventStatus)
 {
   // Send this events straight up to the parent pres shell.
   // We do this for keystroke events in zombie documents or if either a frame
   // or a root content is not present.
   // That way at least the UI key bindings can work.
   nsCOMPtr<nsIPresShell> kungFuDeathGrip(this);
   nsCOMPtr<nsIPresShell> parentPresShell = GetParentPresShellForEventHandling();
   NS_ENSURE_TRUE(parentPresShell, NS_ERROR_FAILURE);
   // Fake the event as though it's from the parent pres shell's root frame.
   return parentPresShell->HandleEvent(parentPresShell->GetRootFrame(), aEvent, true, aEventStatus);
 }
 void
 PresShell::DisableNonTestMouseEvents(bool aDisable)
 {
   sDisableNonTestMouseEvents = aDisable;
 }
 already_AddRefed<nsPIDOMWindow>
 PresShell::GetFocusedDOMWindowInOurWindow()
 {
   nsCOMPtr<nsPIDOMWindow> rootWindow = GetRootWindow();
   NS_ENSURE_TRUE(rootWindow, nullptr);
   nsCOMPtr<nsPIDOMWindow> focusedWindow;
   nsFocusManager::GetFocusedDescendant(rootWindow, true,
                                        getter_AddRefs(focusedWindow));
   return focusedWindow.forget();
 }
 void
 PresShell::RecordMouseLocation(WidgetGUIEvent* aEvent)
 {
   if (!mPresContext)
     return;
   if (!mPresContext->IsRoot()) {
     PresShell* rootPresShell = GetRootPresShell();
     if (rootPresShell) {
       rootPresShell->RecordMouseLocation(aEvent);
     }
     return;
   }
   if ((aEvent->message == NS_MOUSE_MOVE &&
        aEvent->AsMouseEvent()->reason == WidgetMouseEvent::eReal) ||
       aEvent->message == NS_MOUSE_ENTER ||
       aEvent->message == NS_MOUSE_BUTTON_DOWN ||
       aEvent->message == NS_MOUSE_BUTTON_UP) {
     nsIFrame* rootFrame = GetRootFrame();
     if (!rootFrame) {
       nsView* rootView = mViewManager->GetRootView();
       mMouseLocation = nsLayoutUtils::TranslateWidgetToView(mPresContext,
         aEvent->widget, LayoutDeviceIntPoint::ToUntyped(aEvent->refPoint),
         rootView);
     } else {
       mMouseLocation =
         nsLayoutUtils::GetEventCoordinatesRelativeTo(aEvent, rootFrame);
     }
 #ifdef DEBUG_MOUSE_LOCATION
     if (aEvent->message == NS_MOUSE_ENTER)
       printf("[ps=%p]got mouse enter for %p\n",
              this, aEvent->widget);
     printf("[ps=%p]setting mouse location to (%d,%d)\n",
            this, mMouseLocation.x, mMouseLocation.y);
 #endif
     if (aEvent->message == NS_MOUSE_ENTER)
       SynthesizeMouseMove(false);
   } else if (aEvent->message == NS_MOUSE_EXIT) {
     // Although we only care about the mouse moving into an area for which this
     // pres shell doesn't receive mouse move events, we don't check which widget
     // the mouse exit was for since this seems to vary by platform.  Hopefully
     // this won't matter at all since we'll get the mouse move or enter after
     // the mouse exit when the mouse moves from one of our widgets into another.
     mMouseLocation = nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);
 #ifdef DEBUG_MOUSE_LOCATION
     printf("[ps=%p]got mouse exit for %p\n",
            this, aEvent->widget);
     printf("[ps=%p]clearing mouse location\n",
            this);
 #endif
   }
 }
 static void
 EvictTouchPoint(nsRefPtr<dom::Touch>& aTouch,
                 nsIDocument* aLimitToDocument = nullptr)
 {
   nsCOMPtr<nsINode> node(do_QueryInterface(aTouch->mTarget));
   if (node) {
     nsIDocument* doc = node->GetCurrentDoc();
     if (doc && (!aLimitToDocument || aLimitToDocument == doc)) {
       nsIPresShell* presShell = doc->GetShell();
       if (presShell) {
         nsIFrame* frame = presShell->GetRootFrame();
         if (frame) {
           nsPoint pt(aTouch->mRefPoint.x, aTouch->mRefPoint.y);
           nsCOMPtr<nsIWidget> widget = frame->GetView()->GetNearestWidget(&pt);
           if (widget) {
             WidgetTouchEvent event(true, NS_TOUCH_END, widget);
             event.widget = widget;
             event.time = PR_IntervalNow();
             event.touches.AppendElement(aTouch);
             nsEventStatus status;
             widget->DispatchEvent(&event, status);
             return;
           }
         }
       }
     }
   }
   if (!node || !aLimitToDocument || node->OwnerDoc() == aLimitToDocument) {
     // We couldn't dispatch touchend. Remove the touch from gCaptureTouchList
     // explicitly.
     nsIPresShell::gCaptureTouchList->Remove(aTouch->Identifier());
   }
 }
 static PLDHashOperator
 AppendToTouchList(const uint32_t& aKey, nsRefPtr<dom::Touch>& aData, void *aTouchList)
 {
   nsTArray< nsRefPtr<dom::Touch> >* touches =
     static_cast<nsTArray< nsRefPtr<dom::Touch> >*>(aTouchList);
   aData->mChanged = false;
   touches->AppendElement(aData);
   return PL_DHASH_NEXT;
 }
 void
 PresShell::EvictTouches()
 {
   nsTArray< nsRefPtr<dom::Touch> > touches;
   gCaptureTouchList->Enumerate(&AppendToTouchList, &touches);
   for (uint32_t i = 0; i < touches.Length(); ++i) {
     EvictTouchPoint(touches[i], mDocument);
   }
 }
 static PLDHashOperator
 FindAnyTarget(const uint32_t& aKey, nsRefPtr<dom::Touch>& aData,
               void* aAnyTarget)
 {
   if (aData) {
     dom::EventTarget* target = aData->Target();
     if (target) {
       nsCOMPtr<nsIContent>* content =
         static_cast<nsCOMPtr<nsIContent>*>(aAnyTarget);
       *content = do_QueryInterface(target);
       return PL_DHASH_STOP;
     }
   }
   return PL_DHASH_NEXT;
 }
 nsIFrame* GetNearestFrameContainingPresShell(nsIPresShell* aPresShell)
 {
   nsView* view = aPresShell->GetViewManager()->GetRootView();
   while (view && !view->GetFrame()) {
     view = view->GetParent();
   }
   nsIFrame* frame = nullptr;
   if (view) {
     frame = view->GetFrame();
   }
   return frame;
 }
 static bool
 FlushThrottledStyles(nsIDocument *aDocument, void *aData)
 {
   nsIPresShell* shell = aDocument->GetShell();
   if (shell && shell->IsVisible()) {
     nsPresContext* presContext = shell->GetPresContext();
     if (presContext) {
       presContext->TransitionManager()->UpdateAllThrottledStyles();
       presContext->AnimationManager()->UpdateAllThrottledStyles();
     }
   }
   return true;
 }
 static nsresult
 DispatchPointerFromMouseOrTouch(PresShell* aShell,
                                 nsIFrame* aFrame,
                                 WidgetGUIEvent* aEvent,
                                 bool aDontRetargetEvents,
                                 nsEventStatus* aStatus)
 {
   uint32_t pointerMessage = 0;
   if (aEvent->eventStructType == NS_MOUSE_EVENT) {
     WidgetMouseEvent* mouseEvent = aEvent->AsMouseEvent();
     // if it is not mouse then it is likely will come as touch event
     if (!mouseEvent->convertToPointer) {
       return NS_OK;
     }
     int16_t button = mouseEvent->button;
     switch (mouseEvent->message) {
     case NS_MOUSE_MOVE:
       if (mouseEvent->buttons == 0) {
         button = -1;
       }
       pointerMessage = NS_POINTER_MOVE;
       break;
     case NS_MOUSE_BUTTON_UP:
       pointerMessage = NS_POINTER_UP;
       break;
     case NS_MOUSE_BUTTON_DOWN:
       pointerMessage = NS_POINTER_DOWN;
       break;
     default:
       return NS_OK;
     }
     WidgetPointerEvent event(*mouseEvent);
     event.message = pointerMessage;
     event.button = button;
     event.pressure = event.buttons ?
                      mouseEvent->pressure ? mouseEvent->pressure : 0.5f :
 .0f;
     event.convertToPointer = mouseEvent->convertToPointer = false;
     aShell->HandleEvent(aFrame, &event, aDontRetargetEvents, aStatus);
   } else if (aEvent->eventStructType == NS_TOUCH_EVENT) {
     WidgetTouchEvent* touchEvent = aEvent->AsTouchEvent();
     // loop over all touches and dispatch pointer events on each touch
     // copy the event
     switch (touchEvent->message) {
     case NS_TOUCH_MOVE:
       pointerMessage = NS_POINTER_MOVE;
       break;
     case NS_TOUCH_END:
       pointerMessage = NS_POINTER_UP;
       break;
     case NS_TOUCH_START:
       pointerMessage = NS_POINTER_DOWN;
       break;
     case NS_TOUCH_CANCEL:
       pointerMessage = NS_POINTER_CANCEL;
       break;
     default:
       return NS_OK;
     }
     for (uint32_t i = 0; i < touchEvent->touches.Length(); ++i) {
       mozilla::dom::Touch* touch = touchEvent->touches[i];
       if (!touch || !touch->convertToPointer) {
         continue;
       }
       WidgetPointerEvent event(touchEvent->mFlags.mIsTrusted, pointerMessage, touchEvent->widget);
       event.isPrimary = i == 0;
       event.pointerId = touch->Identifier();
       event.refPoint.x = touch->mRefPoint.x;
       event.refPoint.y = touch->mRefPoint.y;
       event.modifiers = touchEvent->modifiers;
       event.width = touch->RadiusX();
       event.height = touch->RadiusY();
       event.tiltX = touch->tiltX;
       event.tiltY = touch->tiltY;
       event.time = touchEvent->time;
       event.mFlags = touchEvent->mFlags;
       event.button = WidgetMouseEvent::eLeftButton;
       event.buttons = WidgetMouseEvent::eLeftButtonFlag;
       event.inputSource = nsIDOMMouseEvent::MOZ_SOURCE_TOUCH;
       event.convertToPointer = touch->convertToPointer = false;
       aShell->HandleEvent(aFrame, &event, aDontRetargetEvents, aStatus);
     }
   }
   return NS_OK;
 }
 class ReleasePointerCaptureCaller
 {
 public:
   ReleasePointerCaptureCaller() :
     mPointerId(0),
     mContent(nullptr)
   {
   }
   ~ReleasePointerCaptureCaller()
   {
     if (mContent) {
       nsIPresShell::ReleasePointerCapturingContent(mPointerId, mContent);
     }
   }
   void SetTarget(uint32_t aPointerId, nsIContent* aContent)
   {
     mPointerId = aPointerId;
     mContent = aContent;
   }
 private:
   int32_t mPointerId;
   nsCOMPtr<nsIContent> mContent;
 };
 nsresult
 PresShell::HandleEvent(nsIFrame* aFrame,
                        WidgetGUIEvent* aEvent,
                        bool aDontRetargetEvents,
                        nsEventStatus* aEventStatus)
 {
 #ifdef MOZ_TASK_TRACER
   // Make touch events, mouse events and hardware key events to be the source
   // events of TaskTracer, and originate the rest correlation tasks from here.
   SourceEventType type = SourceEventType::UNKNOWN;
   if (WidgetTouchEvent* inputEvent = aEvent->AsTouchEvent()) {
     type = SourceEventType::TOUCH;
   } else if (WidgetMouseEvent* inputEvent = aEvent->AsMouseEvent()) {
     type = SourceEventType::MOUSE;
   } else if (WidgetKeyboardEvent* inputEvent = aEvent->AsKeyboardEvent()) {
     type = SourceEventType::KEY;
   }
   AutoSourceEvent taskTracerEvent(type);
 #endif
   if (sPointerEventEnabled) {
     DispatchPointerFromMouseOrTouch(this, aFrame, aEvent, aDontRetargetEvents, aEventStatus);
   }
   NS_ASSERTION(aFrame, "null frame");
   if (mIsDestroying ||
       (sDisableNonTestMouseEvents && !aEvent->mFlags.mIsSynthesizedForTests &&
        aEvent->HasMouseEventMessage())) {
     return NS_OK;
   }
   RecordMouseLocation(aEvent);
   if (sPointerEventEnabled) {
     UpdateActivePointerState(aEvent);
   }
   if (!nsContentUtils::IsSafeToRunScript())
     return NS_OK;
   nsIContent* capturingContent =
     (aEvent->HasMouseEventMessage() ||
      aEvent->eventStructType == NS_WHEEL_EVENT ? GetCapturingContent() :
                                                  nullptr);
   nsCOMPtr<nsIDocument> retargetEventDoc;
   if (!aDontRetargetEvents) {
     // key and IME related events should not cross top level window boundary.
     // Basically, such input events should be fired only on focused widget.
     // However, some IMEs might need to clean up composition after focused
     // window is deactivated.  And also some tests on MozMill want to test key
     // handling on deactivated window because MozMill window can be activated
     // during tests.  So, there is no merit the events should be redirected to
     // active window.  So, the events should be handled on the last focused
     // content in the last focused DOM window in same top level window.
     // Note, if no DOM window has been focused yet, we can discard the events.
     if (aEvent->IsTargetedAtFocusedWindow()) {
       nsCOMPtr<nsPIDOMWindow> window = GetFocusedDOMWindowInOurWindow();
       // No DOM window in same top level window has not been focused yet,
       // discard the events.
       if (!window) {
         return NS_OK;
       }
       retargetEventDoc = window->GetExtantDoc();
       if (!retargetEventDoc)
         return NS_OK;
     } else if (capturingContent) {
       // if the mouse is being captured then retarget the mouse event at the
       // document that is being captured.
       retargetEventDoc = capturingContent->GetCurrentDoc();
 #ifdef ANDROID
     } else if (aEvent->eventStructType == NS_TOUCH_EVENT) {
       retargetEventDoc = GetTouchEventTargetDocument();
 #endif
     }
     if (retargetEventDoc) {
       nsCOMPtr<nsIPresShell> presShell = retargetEventDoc->GetShell();
       if (!presShell)
         return NS_OK;
       if (presShell != this) {
         nsIFrame* frame = presShell->GetRootFrame();
         if (!frame) {
           if (aEvent->message == NS_QUERY_TEXT_CONTENT ||
               aEvent->IsContentCommandEvent()) {
             return NS_OK;
           }
           frame = GetNearestFrameContainingPresShell(presShell);
         }
         if (!frame)
           return NS_OK;
         nsCOMPtr<nsIPresShell> shell = frame->PresContext()->GetPresShell();
         return shell->HandleEvent(frame, aEvent, true, aEventStatus);
       }
     }
   }
   if (aEvent->eventStructType == NS_KEY_EVENT &&
       mDocument && mDocument->EventHandlingSuppressed()) {
     if (aEvent->message == NS_KEY_DOWN) {
       mNoDelayedKeyEvents = true;
     } else if (!mNoDelayedKeyEvents) {
       DelayedEvent* event = new DelayedKeyEvent(aEvent->AsKeyboardEvent());
       if (!mDelayedEvents.AppendElement(event)) {
         delete event;
       }
     }
     return NS_OK;
   }
   nsIFrame* frame = aFrame;
   if (aEvent->IsUsingCoordinates()) {
     ReleasePointerCaptureCaller releasePointerCaptureCaller;
     if (nsLayoutUtils::AreAsyncAnimationsEnabled() && mDocument) {
       if (aEvent->eventStructType == NS_TOUCH_EVENT) {
         nsIDocument::UnlockPointer();
       }
       {  // scope for scriptBlocker.
         nsAutoScriptBlocker scriptBlocker;
         GetRootPresShell()->GetDocument()->
           EnumerateSubDocuments(FlushThrottledStyles, nullptr);
       }
       frame = GetNearestFrameContainingPresShell(this);
     }
     NS_WARN_IF_FALSE(frame, "Nothing to handle this event!");
     if (!frame)
       return NS_OK;
     nsPresContext* framePresContext = frame->PresContext();
     nsPresContext* rootPresContext = framePresContext->GetRootPresContext();
     NS_ASSERTION(rootPresContext == mPresContext->GetRootPresContext(),
                  "How did we end up outside the connected prescontext/viewmanager hierarchy?");
     // If we aren't starting our event dispatch from the root frame of the root prescontext,
     // then someone must be capturing the mouse. In that case we don't want to search the popup
     // list.
     if (framePresContext == rootPresContext &&
         frame == mFrameConstructor->GetRootFrame()) {
       nsIFrame* popupFrame =
         nsLayoutUtils::GetPopupFrameForEventCoordinates(rootPresContext, aEvent);
       // If the popupFrame is an ancestor of the 'frame', the frame should
       // handle the event, otherwise, the popup should handle it.
       if (popupFrame &&
           !nsContentUtils::ContentIsCrossDocDescendantOf(
              framePresContext->GetPresShell()->GetDocument(),
              popupFrame->GetContent())) {
         frame = popupFrame;
       }
     }
     bool captureRetarget = false;
     if (capturingContent) {
       // If a capture is active, determine if the docshell is visible. If not,
       // clear the capture and target the mouse event normally instead. This
       // would occur if the mouse button is held down while a tab change occurs.
       // If the docshell is visible, look for a scrolling container.
       bool vis;
       nsCOMPtr<nsIBaseWindow> baseWin =
         do_QueryInterface(mPresContext->GetContainerWeak());
       if (baseWin && NS_SUCCEEDED(baseWin->GetVisibility(&vis)) && vis) {
         captureRetarget = gCaptureInfo.mRetargetToElement;
         if (!captureRetarget) {
           // A check was already done above to ensure that capturingContent is
           // in this presshell.
           NS_ASSERTION(capturingContent->GetCurrentDoc() == GetDocument(),
                        "Unexpected document");
           nsIFrame* captureFrame = capturingContent->GetPrimaryFrame();
           if (captureFrame) {
             if (capturingContent->Tag() == nsGkAtoms::select &&
                 capturingContent->IsHTML()) {
               // a dropdown <select> has a child in its selectPopupList and we should
               // capture on that instead.
               nsIFrame* childFrame = captureFrame->GetChildList(nsIFrame::kSelectPopupList).FirstChild();
               if (childFrame) {
                 captureFrame = childFrame;
               }
             }
             // scrollable frames should use the scrolling container as
             // the root instead of the document
             nsIScrollableFrame* scrollFrame = do_QueryFrame(captureFrame);
             if (scrollFrame) {
               frame = scrollFrame->GetScrolledFrame();
             }
           }
         }
       }
       else {
         ClearMouseCapture(nullptr);
         capturingContent = nullptr;
       }
     }
     // all touch events except for touchstart use a captured target
     if (aEvent->eventStructType == NS_TOUCH_EVENT &&
         aEvent->message != NS_TOUCH_START) {
       captureRetarget = true;
     }
     WidgetMouseEvent* mouseEvent = aEvent->AsMouseEvent();
     bool isWindowLevelMouseExit = (aEvent->message == NS_MOUSE_EXIT) &&
       (mouseEvent && mouseEvent->exit == WidgetMouseEvent::eTopLevel);
     // Get the frame at the event point. However, don't do this if we're
     // capturing and retargeting the event because the captured frame will
     // be used instead below. Also keep using the root frame if we're dealing
     // with a window-level mouse exit event since we want to start sending
     // mouse out events at the root EventStateManager.
     if (!captureRetarget && !isWindowLevelMouseExit) {
       nsPoint eventPoint;
       uint32_t flags = 0;
       if (aEvent->message == NS_TOUCH_START) {
         flags |= INPUT_IGNORE_ROOT_SCROLL_FRAME;
         WidgetTouchEvent* touchEvent = aEvent->AsTouchEvent();
         // if this is a continuing session, ensure that all these events are
         // in the same document by taking the target of the events already in
         // the capture list
         nsCOMPtr<nsIContent> anyTarget;
         if (gCaptureTouchList->Count() > 0 && touchEvent->touches.Length() > 1) {
           gCaptureTouchList->Enumerate(&FindAnyTarget, &anyTarget);
         } else {
           gPreventMouseEvents = false;
         }
         for (int32_t i = touchEvent->touches.Length(); i; ) {
           --i;
           dom::Touch* touch = touchEvent->touches[i];
           int32_t id = touch->Identifier();
           if (!gCaptureTouchList->Get(id, nullptr)) {
             // find the target for this touch
             eventPoint = nsLayoutUtils::GetEventCoordinatesRelativeTo(aEvent,
                                                               touch->mRefPoint,
                                                               frame);
             nsIFrame* target = FindFrameTargetedByInputEvent(aEvent,
                                                              frame,
                                                              eventPoint,
                                                              flags);
             if (target && !anyTarget) {
               target->GetContentForEvent(aEvent, getter_AddRefs(anyTarget));
               while (anyTarget && !anyTarget->IsElement()) {
                 anyTarget = anyTarget->GetParent();
               }
               touch->SetTarget(anyTarget);
             } else {
               nsIFrame* newTargetFrame = nullptr;
               for (nsIFrame* f = target; f;
                    f = nsLayoutUtils::GetParentOrPlaceholderForCrossDoc(f)) {
                 if (f->PresContext()->Document() == anyTarget->OwnerDoc()) {
                   newTargetFrame = f;
                   break;
                 }
                 // We must be in a subdocument so jump directly to the root frame.
                 // GetParentOrPlaceholderForCrossDoc gets called immediately to
                 // jump up to the containing document.
                 f = f->PresContext()->GetPresShell()->GetRootFrame();
               }
               // if we couldn't find a target frame in the same document as
               // anyTarget, remove the touch from the capture touch list, as
               // well as the event->touches array. touchmove events that aren't
               // in the captured touch list will be discarded
               if (!newTargetFrame) {
                 touchEvent->touches.RemoveElementAt(i);
               } else {
                 target = newTargetFrame;
                 nsCOMPtr<nsIContent> targetContent;
                 target->GetContentForEvent(aEvent, getter_AddRefs(targetContent));
                 while (targetContent && !targetContent->IsElement()) {
                   targetContent = targetContent->GetParent();
                 }
                 touch->SetTarget(targetContent);
               }
             }
             if (target) {
               frame = target;
             }
           } else {
             // This touch is an old touch, we need to ensure that is not
             // marked as changed and set its target correctly
             touch->mChanged = false;
             int32_t id = touch->Identifier();
             nsRefPtr<dom::Touch> oldTouch = gCaptureTouchList->GetWeak(id);
             if (oldTouch) {
               touch->SetTarget(oldTouch->mTarget);
             }
           }
         }
       } else {
         eventPoint = nsLayoutUtils::GetEventCoordinatesRelativeTo(aEvent, frame);
       }
       if (mouseEvent && mouseEvent->eventStructType == NS_MOUSE_EVENT &&
           mouseEvent->ignoreRootScrollFrame) {
         flags |= INPUT_IGNORE_ROOT_SCROLL_FRAME;
       }
       nsIFrame* target =
         FindFrameTargetedByInputEvent(aEvent, frame, eventPoint, flags);
       if (target) {
         frame = target;
       }
     }
     // if a node is capturing the mouse, check if the event needs to be
     // retargeted at the capturing content instead. This will be the case when
     // capture retargeting is being used, no frame was found or the frame's
     // content is not a descendant of the capturing content.
     if (capturingContent &&
         (gCaptureInfo.mRetargetToElement || !frame->GetContent() ||
          !nsContentUtils::ContentIsCrossDocDescendantOf(frame->GetContent(),
                                                         capturingContent))) {
       // A check was already done above to ensure that capturingContent is
       // in this presshell.
       NS_ASSERTION(capturingContent->GetCurrentDoc() == GetDocument(),
                    "Unexpected document");
       nsIFrame* capturingFrame = capturingContent->GetPrimaryFrame();
       if (capturingFrame) {
         frame = capturingFrame;
       }
     }
     if (aEvent->eventStructType == NS_POINTER_EVENT &&
         aEvent->message != NS_POINTER_DOWN) {
       if (WidgetPointerEvent* pointerEvent = aEvent->AsPointerEvent()) {
         uint32_t pointerId = pointerEvent->pointerId;
         nsIContent* pointerCapturingContent = GetPointerCapturingContent(pointerId);
         if (pointerCapturingContent) {
           if (nsIFrame* capturingFrame = pointerCapturingContent->GetPrimaryFrame()) {
             frame = capturingFrame;
           }
           if (pointerEvent->message == NS_POINTER_UP ||
               pointerEvent->message == NS_POINTER_CANCEL) {
             // Implicitly releasing capture for given pointer.
             // LOST_POINTER_CAPTURE should be send after NS_POINTER_UP or NS_POINTER_CANCEL.
             releasePointerCaptureCaller.SetTarget(pointerId, pointerCapturingContent);
           }
         }
       }
     }
     // Suppress mouse event if it's being targeted at an element inside
     // a document which needs events suppressed
     if (aEvent->eventStructType == NS_MOUSE_EVENT &&
         frame->PresContext()->Document()->EventHandlingSuppressed()) {
       if (aEvent->message == NS_MOUSE_BUTTON_DOWN) {
         mNoDelayedMouseEvents = true;
       } else if (!mNoDelayedMouseEvents && aEvent->message == NS_MOUSE_BUTTON_UP) {
         DelayedEvent* event = new DelayedMouseEvent(aEvent->AsMouseEvent());
         if (!mDelayedEvents.AppendElement(event)) {
           delete event;
         }
       }
       return NS_OK;
     }
     PresShell* shell =
         static_cast<PresShell*>(frame->PresContext()->PresShell());
     switch (aEvent->message) {
       case NS_TOUCH_MOVE:
       case NS_TOUCH_CANCEL:
       case NS_TOUCH_END: {
         // get the correct shell to dispatch to
         WidgetTouchEvent* touchEvent = aEvent->AsTouchEvent();
         nsTArray< nsRefPtr<dom::Touch> >& touches = touchEvent->touches;
         for (uint32_t i = 0; i < touches.Length(); ++i) {
           dom::Touch* touch = touches[i];
           if (!touch) {
             break;
           }
           nsRefPtr<dom::Touch> oldTouch =
             gCaptureTouchList->GetWeak(touch->Identifier());
           if (!oldTouch) {
             break;
           }
           nsCOMPtr<nsIContent> content =
             do_QueryInterface(oldTouch->Target());
           if (!content) {
             break;
           }
           nsIFrame* contentFrame = content->GetPrimaryFrame();
           if (!contentFrame) {
             break;
           }
           shell = static_cast<PresShell*>(
                       contentFrame->PresContext()->PresShell());
           if (shell) {
             break;
           }
         }
         break;
       }
     }
     // Check if we have an active EventStateManager which isn't the
     // EventStateManager of the current PresContext.
     // If that is the case, and mouse is over some ancestor document,
     // forward event handling to the active document.
     // This way content can get mouse events even when
     // mouse is over the chrome or outside the window.
     //
     // Note, currently for backwards compatibility we don't forward mouse events
     // to the active document when mouse is over some subdocument.
     EventStateManager* activeESM =
       EventStateManager::GetActiveEventStateManager();
     if (activeESM && aEvent->HasMouseEventMessage() &&
         activeESM != shell->GetPresContext()->EventStateManager() &&
         static_cast<EventStateManager*>(activeESM)->GetPresContext()) {
       nsIPresShell* activeShell =
         static_cast<EventStateManager*>(activeESM)->GetPresContext()->
           GetPresShell();
       if (activeShell &&
           nsContentUtils::ContentIsCrossDocDescendantOf(activeShell->GetDocument(),
                                                         shell->GetDocument())) {
         shell = static_cast<PresShell*>(activeShell);
         frame = shell->GetRootFrame();
       }
     }
     if (shell != this) {
       // Handle the event in the correct shell.
       // Prevent deletion until we're done with event handling (bug 336582).
       nsCOMPtr<nsIPresShell> kungFuDeathGrip(shell);
       // We pass the subshell's root frame as the frame to start from. This is
       // the only correct alternative; if the event was captured then it
       // must have been captured by us or some ancestor shell and we
       // now ask the subshell to dispatch it normally.
       return shell->HandlePositionedEvent(frame, aEvent, aEventStatus);
     }
     return HandlePositionedEvent(frame, aEvent, aEventStatus);
   }
   nsresult rv = NS_OK;
   if (frame) {
     PushCurrentEventInfo(nullptr, nullptr);
     // key and IME related events go to the focused frame in this DOM window.
     if (aEvent->IsTargetedAtFocusedContent()) {
       mCurrentEventContent = nullptr;
       nsCOMPtr<nsPIDOMWindow> window =
         do_QueryInterface(mDocument->GetWindow());
       nsCOMPtr<nsPIDOMWindow> focusedWindow;
       nsCOMPtr<nsIContent> eventTarget =
         nsFocusManager::GetFocusedDescendant(window, false,
                                              getter_AddRefs(focusedWindow));
       // otherwise, if there is no focused content or the focused content has
       // no frame, just use the root content. This ensures that key events
       // still get sent to the window properly if nothing is focused or if a
       // frame goes away while it is focused.
       if (!eventTarget || !eventTarget->GetPrimaryFrame()) {
         nsCOMPtr<nsIDOMHTMLDocument> htmlDoc = do_QueryInterface(mDocument);
         if (htmlDoc) {
           nsCOMPtr<nsIDOMHTMLElement> body;
           htmlDoc->GetBody(getter_AddRefs(body));
           eventTarget = do_QueryInterface(body);
           if (!eventTarget) {
             eventTarget = mDocument->GetRootElement();
           }
         } else {
           eventTarget = mDocument->GetRootElement();
         }
       }
       if (aEvent->message == NS_KEY_DOWN) {
         NS_IF_RELEASE(gKeyDownTarget);
         NS_IF_ADDREF(gKeyDownTarget = eventTarget);
       }
       else if ((aEvent->message == NS_KEY_PRESS || aEvent->message == NS_KEY_UP) &&
                gKeyDownTarget) {
         // If a different element is now focused for the keypress/keyup event
         // than what was focused during the keydown event, check if the new
         // focused element is not in a chrome document any more, and if so,
         // retarget the event back at the keydown target. This prevents a
         // content area from grabbing the focus from chrome in-between key
         // events.
         if (eventTarget &&
             nsContentUtils::IsChromeDoc(gKeyDownTarget->GetCurrentDoc()) !=
             nsContentUtils::IsChromeDoc(eventTarget->GetCurrentDoc())) {
           eventTarget = gKeyDownTarget;
         }
         if (aEvent->message == NS_KEY_UP) {
           NS_RELEASE(gKeyDownTarget);
         }
       }
       mCurrentEventFrame = nullptr;
       nsIDocument* targetDoc = eventTarget ? eventTarget->OwnerDoc() : nullptr;
       if (targetDoc && targetDoc != mDocument) {
         PopCurrentEventInfo();
         nsCOMPtr<nsIPresShell> shell = targetDoc->GetShell();
         if (shell) {
           rv = static_cast<PresShell*>(shell.get())->
             HandleRetargetedEvent(aEvent, aEventStatus, eventTarget);
         }
         return rv;
       } else {
         mCurrentEventContent = eventTarget;
       }
       if (!GetCurrentEventContent() || !GetCurrentEventFrame() ||
           InZombieDocument(mCurrentEventContent)) {
         rv = RetargetEventToParent(aEvent, aEventStatus);
         PopCurrentEventInfo();
         return rv;
       }
     } else {
       mCurrentEventFrame = frame;
     }
     if (GetCurrentEventFrame()) {
       rv = HandleEventInternal(aEvent, aEventStatus);
     }
 #ifdef DEBUG
     ShowEventTargetDebug();
 #endif
     PopCurrentEventInfo();
   } else {
     // Activation events need to be dispatched even if no frame was found, since
     // we don't want the focus to be out of sync.
     if (!NS_EVENT_NEEDS_FRAME(aEvent)) {
       mCurrentEventFrame = nullptr;
       return HandleEventInternal(aEvent, aEventStatus);
     }
     else if (aEvent->HasKeyEventMessage()) {
       // Keypress events in new blank tabs should not be completely thrown away.
       // Retarget them -- the parent chrome shell might make use of them.
       return RetargetEventToParent(aEvent, aEventStatus);
     }
   }
   return rv;
 }
 #ifdef ANDROID
 nsIDocument*
 PresShell::GetTouchEventTargetDocument()
 {
   nsPresContext* context = GetPresContext();
   if (!context || !context->IsRoot()) {
     return nullptr;
   }
   nsCOMPtr<nsIDocShellTreeItem> shellAsTreeItem = context->GetDocShell();
   if (!shellAsTreeItem) {
     return nullptr;
   }
   nsCOMPtr<nsIDocShellTreeOwner> owner;
   shellAsTreeItem->GetTreeOwner(getter_AddRefs(owner));
   if (!owner) {
     return nullptr;
   }
   // now get the primary content shell (active tab)
   nsCOMPtr<nsIDocShellTreeItem> item;
   owner->GetPrimaryContentShell(getter_AddRefs(item));
   nsCOMPtr<nsIDocShell> childDocShell = do_QueryInterface(item);
   nsCOMPtr<nsIDocument> result = do_GetInterface(childDocShell);
   return result;
 }
 #endif
 #ifdef DEBUG
 void
 PresShell::ShowEventTargetDebug()
 {
   if (nsFrame::GetShowEventTargetFrameBorder() &&
       GetCurrentEventFrame()) {
     if (mDrawEventTargetFrame) {
       mDrawEventTargetFrame->InvalidateFrame();
     }
     mDrawEventTargetFrame = mCurrentEventFrame;
     mDrawEventTargetFrame->InvalidateFrame();
   }
 }
 #endif
 nsresult
 PresShell::HandlePositionedEvent(nsIFrame* aTargetFrame,
                                  WidgetGUIEvent* aEvent,
                                  nsEventStatus* aEventStatus)
 {
   nsresult rv = NS_OK;
   PushCurrentEventInfo(nullptr, nullptr);
   mCurrentEventFrame = aTargetFrame;
   if (mCurrentEventFrame) {
     nsCOMPtr<nsIContent> targetElement;
     mCurrentEventFrame->GetContentForEvent(aEvent,
                                            getter_AddRefs(targetElement));
     // If there is no content for this frame, target it anyway.  Some
     // frames can be targeted but do not have content, particularly
     // windows with scrolling off.
     if (targetElement) {
       // Bug 103055, bug 185889: mouse events apply to *elements*, not all
       // nodes.  Thus we get the nearest element parent here.
       // XXX we leave the frame the same even if we find an element
       // parent, so that the text frame will receive the event (selection
       // and friends are the ones who care about that anyway)
       //
       // We use weak pointers because during this tight loop, the node
       // will *not* go away.  And this happens on every mousemove.
       while (targetElement && !targetElement->IsElement()) {
         targetElement = targetElement->GetParent();
       }
       // If we found an element, target it.  Otherwise, target *nothing*.
       if (!targetElement) {
         mCurrentEventContent = nullptr;
         mCurrentEventFrame = nullptr;
       } else if (targetElement != mCurrentEventContent) {
         mCurrentEventContent = targetElement;
       }
     }
   }
   if (GetCurrentEventFrame()) {
     rv = HandleEventInternal(aEvent, aEventStatus);
   }
 #ifdef DEBUG
   ShowEventTargetDebug();
 #endif
   PopCurrentEventInfo();
   return rv;
 }
 nsresult
 PresShell::HandleEventWithTarget(WidgetEvent* aEvent, nsIFrame* aFrame,
                                  nsIContent* aContent, nsEventStatus* aStatus)
 {
 #if DEBUG
   MOZ_ASSERT(!aFrame || aFrame->PresContext()->GetPresShell() == this,
              "wrong shell");
   if (aContent) {
     nsIDocument* doc = aContent->GetCurrentDoc();
     NS_ASSERTION(doc, "event for content that isn't in a document");
     NS_ASSERTION(!doc || doc->GetShell() == this, "wrong shell");
   }
 #endif
   NS_ENSURE_STATE(!aContent || aContent->GetCurrentDoc() == mDocument);
   PushCurrentEventInfo(aFrame, aContent);
   nsresult rv = HandleEventInternal(aEvent, aStatus);
   PopCurrentEventInfo();
   return rv;
 }
 nsresult
 PresShell::HandleEventInternal(WidgetEvent* aEvent, nsEventStatus* aStatus)
 {
   nsRefPtr<EventStateManager> manager = mPresContext->EventStateManager();
   nsresult rv = NS_OK;
   if (!NS_EVENT_NEEDS_FRAME(aEvent) || GetCurrentEventFrame()) {
     bool touchIsNew = false;
     bool isHandlingUserInput = false;
     // XXX How about IME events and input events for plugins?
     if (aEvent->mFlags.mIsTrusted) {
       switch (aEvent->message) {
       case NS_KEY_PRESS:
       case NS_KEY_DOWN:
       case NS_KEY_UP: {
         nsIDocument* doc = GetCurrentEventContent() ?
                            mCurrentEventContent->OwnerDoc() : nullptr;
         nsIDocument* fullscreenAncestor = nullptr;
         if (aEvent->AsKeyboardEvent()->keyCode == NS_VK_ESCAPE) {
           if ((fullscreenAncestor = nsContentUtils::GetFullscreenAncestor(doc))) {
             // Prevent default action on ESC key press when exiting
             // DOM fullscreen mode. This prevents the browser ESC key
             // handler from stopping all loads in the document, which
             // would cause <video> loads to stop.
             aEvent->mFlags.mDefaultPrevented = true;
             aEvent->mFlags.mOnlyChromeDispatch = true;
             if (aEvent->message == NS_KEY_UP) {
               // ESC key released while in DOM fullscreen mode.
               // If fullscreen is running in content-only mode, exit the target
               // doctree branch from fullscreen, otherwise fully exit all
               // browser windows and documents from fullscreen mode.
               // Note: in the content-only fullscreen case, we pass the
               // fullscreenAncestor since |doc| may not actually be fullscreen
               // here, and ExitFullscreen() has no affect when passed a
               // non-fullscreen document.
               nsIDocument::ExitFullscreen(
                 nsContentUtils::IsFullscreenApiContentOnly() ? fullscreenAncestor : nullptr,
                 /* async */ true);
             }
           }
           nsCOMPtr<nsIDocument> pointerLockedDoc =
             do_QueryReferent(EventStateManager::sPointerLockedDoc);
           if (pointerLockedDoc) {
             aEvent->mFlags.mDefaultPrevented = true;
             aEvent->mFlags.mOnlyChromeDispatch = true;
             if (aEvent->message == NS_KEY_UP) {
               nsIDocument::UnlockPointer();
             }
           }
         }
         // Else not full-screen mode or key code is unrestricted, fall
         // through to normal handling.
       }
       case NS_MOUSE_BUTTON_DOWN:
       case NS_MOUSE_BUTTON_UP:
         isHandlingUserInput = true;
         break;
       case NS_TOUCH_START: {
         WidgetTouchEvent* touchEvent = aEvent->AsTouchEvent();
         // if there is only one touch in this touchstart event, assume that it is
         // the start of a new touch session and evict any old touches in the
         // queue
         if (touchEvent->touches.Length() == 1) {
           nsTArray< nsRefPtr<dom::Touch> > touches;
           gCaptureTouchList->Enumerate(&AppendToTouchList, (void *)&touches);
           for (uint32_t i = 0; i < touches.Length(); ++i) {
             EvictTouchPoint(touches[i]);
           }
         }
         // Add any new touches to the queue
         for (uint32_t i = 0; i < touchEvent->touches.Length(); ++i) {
           dom::Touch* touch = touchEvent->touches[i];
           int32_t id = touch->Identifier();
           if (!gCaptureTouchList->Get(id, nullptr)) {
             // If it is not already in the queue, it is a new touch
             touch->mChanged = true;
           }
           touch->mMessage = aEvent->message;
           gCaptureTouchList->Put(id, touch);
         }
         break;
       }
       case NS_TOUCH_CANCEL:
       case NS_TOUCH_END: {
         // Remove the changed touches
         // need to make sure we only remove touches that are ending here
         WidgetTouchEvent* touchEvent = aEvent->AsTouchEvent();
         nsTArray< nsRefPtr<dom::Touch> >& touches = touchEvent->touches;
         for (uint32_t i = 0; i < touches.Length(); ++i) {
           dom::Touch* touch = touches[i];
           if (!touch) {
             continue;
           }
           touch->mMessage = aEvent->message;
           touch->mChanged = true;
           int32_t id = touch->Identifier();
           nsRefPtr<dom::Touch> oldTouch = gCaptureTouchList->GetWeak(id);
           if (!oldTouch) {
             continue;
           }
           nsCOMPtr<EventTarget> targetPtr = oldTouch->mTarget;
           mCurrentEventContent = do_QueryInterface(targetPtr);
           touch->SetTarget(targetPtr);
           gCaptureTouchList->Remove(id);
         }
         // add any touches left in the touch list, but ensure changed=false
         gCaptureTouchList->Enumerate(&AppendToTouchList, (void *)&touches);
         break;
       }
       case NS_TOUCH_MOVE: {
         // Check for touches that changed. Mark them add to queue
         WidgetTouchEvent* touchEvent = aEvent->AsTouchEvent();
         nsTArray< nsRefPtr<dom::Touch> >& touches = touchEvent->touches;
         bool haveChanged = false;
         for (int32_t i = touches.Length(); i; ) {
           --i;
           dom::Touch* touch = touches[i];
           if (!touch) {
             continue;
           }
           int32_t id = touch->Identifier();
           touch->mMessage = aEvent->message;
           nsRefPtr<dom::Touch> oldTouch = gCaptureTouchList->GetWeak(id);
           if (!oldTouch) {
             touches.RemoveElementAt(i);
             continue;
           }
           if (!touch->Equals(oldTouch)) {
             touch->mChanged = true;
             haveChanged = true;
           }
           nsCOMPtr<dom::EventTarget> targetPtr = oldTouch->mTarget;
           if (!targetPtr) {
             touches.RemoveElementAt(i);
             continue;
           }
           touch->SetTarget(targetPtr);
           gCaptureTouchList->Put(id, touch);
           // if we're moving from touchstart to touchmove for this touch
           // we allow preventDefault to prevent mouse events
           if (oldTouch->mMessage != touch->mMessage) {
             touchIsNew = true;
           }
         }
         // is nothing has changed, we should just return
         if (!haveChanged) {
           if (gPreventMouseEvents) {
               *aStatus = nsEventStatus_eConsumeNoDefault;
           }
           return NS_OK;
         }
         break;
       }
       case NS_DRAGDROP_DROP:
         nsCOMPtr<nsIDragSession> session = nsContentUtils::GetDragSession();
         if (session) {
           bool onlyChromeDrop = false;
           session->GetOnlyChromeDrop(&onlyChromeDrop);
           if (onlyChromeDrop) {
             aEvent->mFlags.mOnlyChromeDispatch = true;
           }
         }
         break;
       }
     }
     if (aEvent->message == NS_CONTEXTMENU) {
       WidgetMouseEvent* mouseEvent = aEvent->AsMouseEvent();
       if (mouseEvent->context == WidgetMouseEvent::eContextMenuKey &&
           !AdjustContextMenuKeyEvent(mouseEvent)) {
         return NS_OK;
       }
       if (mouseEvent->IsShift()) {
         aEvent->mFlags.mOnlyChromeDispatch = true;
         aEvent->mFlags.mRetargetToNonNativeAnonymous = true;
       }
     }
     AutoHandlingUserInputStatePusher userInpStatePusher(isHandlingUserInput,
                                                         aEvent, mDocument);
     if (aEvent->mFlags.mIsTrusted && aEvent->message == NS_MOUSE_MOVE) {
       nsIPresShell::AllowMouseCapture(
         EventStateManager::GetActiveEventStateManager() == manager);
     }
     nsAutoPopupStatePusher popupStatePusher(
                              Event::GetEventPopupControlState(aEvent));
     // FIXME. If the event was reused, we need to clear the old target,
     // bug 329430
     aEvent->target = nullptr;
     // 1. Give event to event manager for pre event state changes and
     //    generation of synthetic events.
     rv = manager->PreHandleEvent(mPresContext, aEvent, mCurrentEventFrame, aStatus);
     // 2. Give event to the DOM for third party and JS use.
     if (NS_SUCCEEDED(rv)) {
       bool wasHandlingKeyBoardEvent =
         nsContentUtils::IsHandlingKeyBoardEvent();
       if (aEvent->eventStructType == NS_KEY_EVENT) {
         nsContentUtils::SetIsHandlingKeyBoardEvent(true);
       }
       if (aEvent->IsAllowedToDispatchDOMEvent()) {
         nsPresShellEventCB eventCB(this);
         if (aEvent->eventStructType == NS_TOUCH_EVENT) {
           DispatchTouchEvent(aEvent, aStatus, &eventCB, touchIsNew);
         } else {
           nsCOMPtr<nsINode> eventTarget = mCurrentEventContent.get();
           nsPresShellEventCB* eventCBPtr = &eventCB;
           if (!eventTarget) {
             nsCOMPtr<nsIContent> targetContent;
             if (mCurrentEventFrame) {
               rv = mCurrentEventFrame->
                      GetContentForEvent(aEvent, getter_AddRefs(targetContent));
             }
             if (NS_SUCCEEDED(rv) && targetContent) {
               eventTarget = do_QueryInterface(targetContent);
             } else if (mDocument) {
               eventTarget = do_QueryInterface(mDocument);
               // If we don't have any content, the callback wouldn't probably
               // do nothing.
               eventCBPtr = nullptr;
             }
           }
           if (eventTarget) {
             if (aEvent->eventStructType == NS_COMPOSITION_EVENT ||
                 aEvent->eventStructType == NS_TEXT_EVENT) {
               IMEStateManager::DispatchCompositionEvent(eventTarget,
                 mPresContext, aEvent, aStatus, eventCBPtr);
             } else {
               EventDispatcher::Dispatch(eventTarget, mPresContext,
                                         aEvent, nullptr, aStatus, eventCBPtr);
             }
           }
         }
       }
       nsContentUtils::SetIsHandlingKeyBoardEvent(wasHandlingKeyBoardEvent);
       // 3. Give event to event manager for post event state changes and
       //    generation of synthetic events.
       if (!mIsDestroying && NS_SUCCEEDED(rv)) {
         rv = manager->PostHandleEvent(mPresContext, aEvent,
                                       GetCurrentEventFrame(), aStatus);
       }
     }
     if (aEvent->message == NS_MOUSE_BUTTON_UP) {
       // reset the capturing content now that the mouse button is up
       SetCapturingContent(nullptr, 0);
     } else if (aEvent->message == NS_MOUSE_MOVE) {
       nsIPresShell::AllowMouseCapture(false);
     }
   }
   return rv;
 }
 void
 nsIPresShell::DispatchGotOrLostPointerCaptureEvent(bool aIsGotCapture,
                                                    uint32_t aPointerId,
                                                    nsIContent* aCaptureTarget)
 {
   PointerEventInit init;
   init.mPointerId = aPointerId;
   init.mBubbles = true;
   nsRefPtr<mozilla::dom::PointerEvent> event;
   event = PointerEvent::Constructor(aCaptureTarget,
                                     aIsGotCapture
                                       ? NS_LITERAL_STRING("gotpointercapture")
                                       : NS_LITERAL_STRING("lostpointercapture"),
                                     init);
   if (event) {
     bool dummy;
     aCaptureTarget->DispatchEvent(event->InternalDOMEvent(), &dummy);
   }
 }
 void
 PresShell::DispatchTouchEvent(WidgetEvent* aEvent,
                               nsEventStatus* aStatus,
                               nsPresShellEventCB* aEventCB,
                               bool aTouchIsNew)
 {
   // calling preventDefault on touchstart or the first touchmove for a
   // point prevents mouse events
   bool canPrevent = aEvent->message == NS_TOUCH_START ||
               (aEvent->message == NS_TOUCH_MOVE && aTouchIsNew);
   bool preventDefault = false;
   nsEventStatus tmpStatus = nsEventStatus_eIgnore;
   WidgetTouchEvent* touchEvent = aEvent->AsTouchEvent();
   // loop over all touches and dispatch events on any that have changed
   for (uint32_t i = 0; i < touchEvent->touches.Length(); ++i) {
     dom::Touch* touch = touchEvent->touches[i];
     if (!touch || !touch->mChanged) {
       continue;
     }
     nsCOMPtr<EventTarget> targetPtr = touch->mTarget;
     nsCOMPtr<nsIContent> content = do_QueryInterface(targetPtr);
     if (!content) {
       continue;
     }
     nsIDocument* doc = content->OwnerDoc();
     nsIContent* capturingContent = GetCapturingContent();
     if (capturingContent) {
       if (capturingContent->OwnerDoc() != doc) {
         // Wrong document, don't dispatch anything.
         continue;
       }
       content = capturingContent;
     }
     // copy the event
     WidgetTouchEvent newEvent(touchEvent->mFlags.mIsTrusted,
                               touchEvent->message, touchEvent->widget);
     newEvent.AssignTouchEventData(*touchEvent, false);
     newEvent.target = targetPtr;
     nsRefPtr<PresShell> contentPresShell;
     if (doc == mDocument) {
       contentPresShell = static_cast<PresShell*>(doc->GetShell());
       if (contentPresShell) {
         //XXXsmaug huge hack. Pushing possibly capturing content,
         //         even though event target is something else.
         contentPresShell->PushCurrentEventInfo(
             content->GetPrimaryFrame(), content);
       }
     }
     nsIPresShell *presShell = doc->GetShell();
     if (!presShell) {
       continue;
     }
     nsPresContext *context = presShell->GetPresContext();
     tmpStatus = nsEventStatus_eIgnore;
     EventDispatcher::Dispatch(targetPtr, context,
                               &newEvent, nullptr, &tmpStatus, aEventCB);
     if (nsEventStatus_eConsumeNoDefault == tmpStatus ||
         newEvent.mFlags.mMultipleActionsPrevented) {
       preventDefault = true;
     }
     if (newEvent.mFlags.mMultipleActionsPrevented) {
       touchEvent->mFlags.mMultipleActionsPrevented = true;
     }
     if (contentPresShell) {
       contentPresShell->PopCurrentEventInfo();
     }
   }
   // if preventDefault was called on any of the events dispatched
   // and this is touchstart, or the first touchmove, widget should consume
   // other events that would be associated with this touch session
   if (preventDefault && canPrevent) {
     gPreventMouseEvents = true;
   }
   if (gPreventMouseEvents) {
     *aStatus = nsEventStatus_eConsumeNoDefault;
   } else {
     *aStatus = nsEventStatus_eIgnore;
   }
 }
 // Dispatch event to content only (NOT full processing)
 // See also HandleEventWithTarget which does full event processing.
 nsresult
 PresShell::HandleDOMEventWithTarget(nsIContent* aTargetContent,
                                     WidgetEvent* aEvent,
                                     nsEventStatus* aStatus)
 {
   nsresult rv = NS_OK;
   PushCurrentEventInfo(nullptr, aTargetContent);
   // Bug 41013: Check if the event should be dispatched to content.
   // It's possible that we are in the middle of destroying the window
   // and the js context is out of date. This check detects the case
   // that caused a crash in bug 41013, but there may be a better way
   // to handle this situation!
   nsCOMPtr<nsISupports> container = mPresContext->GetContainerWeak();
   if (container) {
     // Dispatch event to content
     rv = EventDispatcher::Dispatch(aTargetContent, mPresContext, aEvent,
                                    nullptr, aStatus);
   }
   PopCurrentEventInfo();
   return rv;
 }
 // See the method above.
 nsresult
 PresShell::HandleDOMEventWithTarget(nsIContent* aTargetContent,
                                     nsIDOMEvent* aEvent,
                                     nsEventStatus* aStatus)
 {
   nsresult rv = NS_OK;
   PushCurrentEventInfo(nullptr, aTargetContent);
   nsCOMPtr<nsISupports> container = mPresContext->GetContainerWeak();
   if (container) {
     rv = EventDispatcher::DispatchDOMEvent(aTargetContent, nullptr, aEvent,
                                            mPresContext, aStatus);
   }
   PopCurrentEventInfo();
   return rv;
 }
 bool
 PresShell::AdjustContextMenuKeyEvent(WidgetMouseEvent* aEvent)
 {
 #ifdef MOZ_XUL
   // if a menu is open, open the context menu relative to the active item on the menu.
   nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
   if (pm) {
     nsIFrame* popupFrame = pm->GetTopPopup(ePopupTypeMenu);
     if (popupFrame) {
       nsIFrame* itemFrame =
         (static_cast<nsMenuPopupFrame *>(popupFrame))->GetCurrentMenuItem();
       if (!itemFrame)
         itemFrame = popupFrame;
       nsCOMPtr<nsIWidget> widget = popupFrame->GetNearestWidget();
       aEvent->widget = widget;
       nsIntPoint widgetPoint = widget->WidgetToScreenOffset();
       aEvent->refPoint = LayoutDeviceIntPoint::FromUntyped(
         itemFrame->GetScreenRect().BottomLeft() - widgetPoint);
       mCurrentEventContent = itemFrame->GetContent();
       mCurrentEventFrame = itemFrame;
       return true;
     }
   }
 #endif
   // If we're here because of the key-equiv for showing context menus, we
   // have to twiddle with the NS event to make sure the context menu comes
   // up in the upper left of the relevant content area before we create
   // the DOM event. Since we never call InitMouseEvent() on the event,
   // the client X/Y will be 0,0. We can make use of that if the widget is null.
   // Use the root view manager's widget since it's most likely to have one,
   // and the coordinates returned by GetCurrentItemAndPositionForElement
   // are relative to the widget of the root of the root view manager.
   nsRootPresContext* rootPC = mPresContext->GetRootPresContext();
   aEvent->refPoint.x = 0;
   aEvent->refPoint.y = 0;
   if (rootPC) {
     rootPC->PresShell()->GetViewManager()->
       GetRootWidget(getter_AddRefs(aEvent->widget));
     if (aEvent->widget) {
       // default the refpoint to the topleft of our document
       nsPoint offset(0, 0);
       nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
       if (rootFrame) {
         nsView* view = rootFrame->GetClosestView(&offset);
         offset += view->GetOffsetToWidget(aEvent->widget);
         aEvent->refPoint =
           LayoutDeviceIntPoint::FromAppUnitsToNearest(offset, mPresContext->AppUnitsPerDevPixel());
       }
     }
   } else {
     aEvent->widget = nullptr;
   }
   // see if we should use the caret position for the popup
   nsIntPoint caretPoint;
   // Beware! This may flush notifications via synchronous
   // ScrollSelectionIntoView.
   if (PrepareToUseCaretPosition(aEvent->widget, caretPoint)) {
     // caret position is good
     aEvent->refPoint = LayoutDeviceIntPoint::FromUntyped(caretPoint);
     return true;
   }
   // If we're here because of the key-equiv for showing context menus, we
   // have to reset the event target to the currently focused element. Get it
   // from the focus controller.
   nsCOMPtr<nsIDOMElement> currentFocus;
   nsIFocusManager* fm = nsFocusManager::GetFocusManager();
   if (fm)
     fm->GetFocusedElement(getter_AddRefs(currentFocus));
   // Reset event coordinates relative to focused frame in view
   if (currentFocus) {
     nsCOMPtr<nsIContent> currentPointElement;
     GetCurrentItemAndPositionForElement(currentFocus,
                                         getter_AddRefs(currentPointElement),
                                         aEvent->refPoint,
                                         aEvent->widget);
     if (currentPointElement) {
       mCurrentEventContent = currentPointElement;
       mCurrentEventFrame = nullptr;
       GetCurrentEventFrame();
     }
   }
   return true;
 }
 // PresShell::PrepareToUseCaretPosition
 //
 //    This checks to see if we should use the caret position for popup context
 //    menus. Returns true if the caret position should be used, and the
 //    coordinates of that position is returned in aTargetPt. This function
 //    will also scroll the window as needed to make the caret visible.
 //
 //    The event widget should be the widget that generated the event, and
 //    whose coordinate system the resulting event's refPoint should be
 //    relative to.  The returned point is in device pixels realtive to the
 //    widget passed in.
 bool
 PresShell::PrepareToUseCaretPosition(nsIWidget* aEventWidget, nsIntPoint& aTargetPt)
 {
   nsresult rv;
   // check caret visibility
   nsRefPtr<nsCaret> caret = GetCaret();
   NS_ENSURE_TRUE(caret, false);
   bool caretVisible = false;
   rv = caret->GetCaretVisible(&caretVisible);
   if (NS_FAILED(rv) || ! caretVisible)
     return false;
   // caret selection, this is a temporary weak reference, so no refcounting is
   // needed
   nsISelection* domSelection = caret->GetCaretDOMSelection();
   NS_ENSURE_TRUE(domSelection, false);
   // since the match could be an anonymous textnode inside a
   // <textarea> or text <input>, we need to get the outer frame
   // note: frames are not refcounted
   nsIFrame* frame = nullptr; // may be nullptr
   nsCOMPtr<nsIDOMNode> node;
   rv = domSelection->GetFocusNode(getter_AddRefs(node));
   NS_ENSURE_SUCCESS(rv, false);
   NS_ENSURE_TRUE(node, false);
   nsCOMPtr<nsIContent> content(do_QueryInterface(node));
   if (content) {
     nsIContent* nonNative = content->FindFirstNonChromeOnlyAccessContent();
     content = nonNative;
   }
   if (content) {
     // It seems like ScrollSelectionIntoView should be enough, but it's
     // not. The problem is that scrolling the selection into view when it is
     // below the current viewport will align the top line of the frame exactly
     // with the bottom of the window. This is fine, BUT, the popup event causes
     // the control to be re-focused which does this exact call to
     // ScrollContentIntoView, which has a one-pixel disagreement of whether the
     // frame is actually in view. The result is that the frame is aligned with
     // the top of the window, but the menu is still at the bottom.
     //
     // Doing this call first forces the frame to be in view, eliminating the
     // problem. The only difference in the result is that if your cursor is in
     // an edit box below the current view, you'll get the edit box aligned with
     // the top of the window. This is arguably better behavior anyway.
     rv = ScrollContentIntoView(content,
                                nsIPresShell::ScrollAxis(
                                  nsIPresShell::SCROLL_MINIMUM,
                                  nsIPresShell::SCROLL_IF_NOT_VISIBLE),
                                nsIPresShell::ScrollAxis(
                                  nsIPresShell::SCROLL_MINIMUM,
                                  nsIPresShell::SCROLL_IF_NOT_VISIBLE),
                                nsIPresShell::SCROLL_OVERFLOW_HIDDEN);
     NS_ENSURE_SUCCESS(rv, false);
     frame = content->GetPrimaryFrame();
     NS_WARN_IF_FALSE(frame, "No frame for focused content?");
   }
   // Actually scroll the selection (ie caret) into view. Note that this must
   // be synchronous since we will be checking the caret position on the screen.
   //
   // Be easy about errors, and just don't scroll in those cases. Better to have
   // the correct menu at a weird place than the wrong menu.
   // After ScrollSelectionIntoView(), the pending notifications might be
   // flushed and PresShell/PresContext/Frames may be dead. See bug 418470.
   nsCOMPtr<nsISelectionController> selCon;
   if (frame)
     frame->GetSelectionController(GetPresContext(), getter_AddRefs(selCon));
   else
     selCon = static_cast<nsISelectionController *>(this);
   if (selCon) {
     rv = selCon->ScrollSelectionIntoView(nsISelectionController::SELECTION_NORMAL,
                                          nsISelectionController::SELECTION_FOCUS_REGION,
                                          nsISelectionController::SCROLL_SYNCHRONOUS);
     NS_ENSURE_SUCCESS(rv, false);
   }
   nsPresContext* presContext = GetPresContext();
   // get caret position relative to the closest view
   nsRect caretCoords;
   nsIFrame* caretFrame = caret->GetGeometry(domSelection, &caretCoords);
   if (!caretFrame)
     return false;
   nsPoint viewOffset;
   nsView* view = caretFrame->GetClosestView(&viewOffset);
   if (!view)
     return false;
   // and then get the caret coords relative to the event widget
   if (aEventWidget) {
     viewOffset += view->GetOffsetToWidget(aEventWidget);
   }
   caretCoords.MoveBy(viewOffset);
   // caret coordinates are in app units, convert to pixels
   aTargetPt.x =
     presContext->AppUnitsToDevPixels(caretCoords.x + caretCoords.width);
   aTargetPt.y =
     presContext->AppUnitsToDevPixels(caretCoords.y + caretCoords.height);
   // make sure rounding doesn't return a pixel which is outside the caret
   // (e.g. one line lower)
   aTargetPt.y -= 1;
   return true;
 }
 void
 PresShell::GetCurrentItemAndPositionForElement(nsIDOMElement *aCurrentEl,
                                                nsIContent** aTargetToUse,
                                                LayoutDeviceIntPoint& aTargetPt,
                                                nsIWidget *aRootWidget)
 {
   nsCOMPtr<nsIContent> focusedContent(do_QueryInterface(aCurrentEl));
   ScrollContentIntoView(focusedContent,
                         ScrollAxis(),
                         ScrollAxis(),
                         nsIPresShell::SCROLL_OVERFLOW_HIDDEN);
   nsPresContext* presContext = GetPresContext();
   bool istree = false, checkLineHeight = true;
   nscoord extraTreeY = 0;
 #ifdef MOZ_XUL
   // Set the position to just underneath the current item for multi-select
   // lists or just underneath the selected item for single-select lists. If
   // the element is not a list, or there is no selection, leave the position
   // as is.
   nsCOMPtr<nsIDOMXULSelectControlItemElement> item;
   nsCOMPtr<nsIDOMXULMultiSelectControlElement> multiSelect =
     do_QueryInterface(aCurrentEl);
   if (multiSelect) {
     checkLineHeight = false;
     int32_t currentIndex;
     multiSelect->GetCurrentIndex(&currentIndex);
     if (currentIndex >= 0) {
       nsCOMPtr<nsIDOMXULElement> xulElement(do_QueryInterface(aCurrentEl));
       if (xulElement) {
         nsCOMPtr<nsIBoxObject> box;
         xulElement->GetBoxObject(getter_AddRefs(box));
         nsCOMPtr<nsITreeBoxObject> treeBox(do_QueryInterface(box));
         // Tree view special case (tree items have no frames)
         // Get the focused row and add its coordinates, which are already in pixels
         // XXX Boris, should we create a new interface so that this doesn't
         // need to know about trees? Something like nsINodelessChildCreator which
         // could provide the current focus coordinates?
         if (treeBox) {
           treeBox->EnsureRowIsVisible(currentIndex);
           int32_t firstVisibleRow, rowHeight;
           treeBox->GetFirstVisibleRow(&firstVisibleRow);
           treeBox->GetRowHeight(&rowHeight);
           extraTreeY += presContext->CSSPixelsToAppUnits(
                           (currentIndex - firstVisibleRow + 1) * rowHeight);
           istree = true;
           nsCOMPtr<nsITreeColumns> cols;
           treeBox->GetColumns(getter_AddRefs(cols));
           if (cols) {
             nsCOMPtr<nsITreeColumn> col;
             cols->GetFirstColumn(getter_AddRefs(col));
             if (col) {
               nsCOMPtr<nsIDOMElement> colElement;
               col->GetElement(getter_AddRefs(colElement));
               nsCOMPtr<nsIContent> colContent(do_QueryInterface(colElement));
               if (colContent) {
                 nsIFrame* frame = colContent->GetPrimaryFrame();
                 if (frame) {
                   extraTreeY += frame->GetSize().height;
                 }
               }
             }
           }
         }
         else {
           multiSelect->GetCurrentItem(getter_AddRefs(item));
         }
       }
     }
   }
   else {
     // don't check menulists as the selected item will be inside a popup.
     nsCOMPtr<nsIDOMXULMenuListElement> menulist = do_QueryInterface(aCurrentEl);
     if (!menulist) {
       nsCOMPtr<nsIDOMXULSelectControlElement> select =
         do_QueryInterface(aCurrentEl);
       if (select) {
         checkLineHeight = false;
         select->GetSelectedItem(getter_AddRefs(item));
       }
     }
   }
   if (item)
     focusedContent = do_QueryInterface(item);
 #endif
   nsIFrame *frame = focusedContent->GetPrimaryFrame();
   if (frame) {
     NS_ASSERTION(frame->PresContext() == GetPresContext(),
       "handling event for focused content that is not in our document?");
     nsPoint frameOrigin(0, 0);
     // Get the frame's origin within its view
     nsView *view = frame->GetClosestView(&frameOrigin);
     NS_ASSERTION(view, "No view for frame");
     // View's origin relative the widget
     if (aRootWidget) {
       frameOrigin += view->GetOffsetToWidget(aRootWidget);
     }
     // Start context menu down and to the right from top left of frame
     // use the lineheight. This is a good distance to move the context
     // menu away from the top left corner of the frame. If we always
     // used the frame height, the context menu could end up far away,
     // for example when we're focused on linked images.
     // On the other hand, we want to use the frame height if it's less
     // than the current line height, so that the context menu appears
     // associated with the correct frame.
     nscoord extra = 0;
     if (!istree) {
       extra = frame->GetSize().height;
       if (checkLineHeight) {
         nsIScrollableFrame *scrollFrame =
           nsLayoutUtils::GetNearestScrollableFrame(frame);
         if (scrollFrame) {
           nsSize scrollAmount = scrollFrame->GetLineScrollAmount();
           nsIFrame* f = do_QueryFrame(scrollFrame);
           int32_t APD = presContext->AppUnitsPerDevPixel();
           int32_t scrollAPD = f->PresContext()->AppUnitsPerDevPixel();
           scrollAmount = scrollAmount.ConvertAppUnits(scrollAPD, APD);
           if (extra > scrollAmount.height) {
             extra = scrollAmount.height;
           }
         }
       }
     }
     aTargetPt.x = presContext->AppUnitsToDevPixels(frameOrigin.x);
     aTargetPt.y = presContext->AppUnitsToDevPixels(
                     frameOrigin.y + extra + extraTreeY);
   }
   NS_IF_ADDREF(*aTargetToUse = focusedContent);
 }
 bool
 PresShell::ShouldIgnoreInvalidation()
 {
   return mPaintingSuppressed || !mIsActive || mIsNeverPainting;
 }
 void
 PresShell::WillPaint()
 {
   nsRootPresContext* rootPresContext = mPresContext->GetRootPresContext();
   if (!rootPresContext) {
     // In some edge cases, such as when we don't have a root frame yet,
     // we can't find the root prescontext. There's nothing to do in that
     // case.
     return;
   }
   // Don't bother doing anything if some viewmanager in our tree is painting
   // while we still have painting suppressed or we are not active.
   if (mPaintingSuppressed || !mIsActive || !IsVisible()) {
     return;
   }
   rootPresContext->FlushWillPaintObservers();
   if (mIsDestroying)
     return;
   // Process reflows, if we have them, to reduce flicker due to invalidates and
   // reflow being interspersed.  Note that we _do_ allow this to be
   // interruptible; if we can't do all the reflows it's better to flicker a bit
   // than to freeze up.
   FlushPendingNotifications(ChangesToFlush(Flush_InterruptibleLayout, false));
 }
 void
 PresShell::WillPaintWindow()
 {
   nsRootPresContext* rootPresContext = mPresContext->GetRootPresContext();
   if (rootPresContext != mPresContext) {
     // This could be a popup's presshell. We don't allow plugins in popups
     // so there's nothing to do here.
     return;
   }
 #ifndef XP_MACOSX
   rootPresContext->ApplyPluginGeometryUpdates();
 #endif
 }
 void
 PresShell::DidPaintWindow()
 {
   nsRootPresContext* rootPresContext = mPresContext->GetRootPresContext();
   if (rootPresContext != mPresContext) {
     // This could be a popup's presshell. No point in notifying XPConnect
     // about compositing of popups.
     return;
   }
   if (nsContentUtils::XPConnect()) {
     nsContentUtils::XPConnect()->NotifyDidPaint();
   }
 }
 bool
 PresShell::IsVisible()
 {
   if (!mViewManager)
     return false;
   nsView* view = mViewManager->GetRootView();
   if (!view)
     return true;
   // inner view of subdoc frame
   view = view->GetParent();
   if (!view)
     return true;
   // subdoc view
   view = view->GetParent();
   if (!view)
     return true;
   nsIFrame* frame = view->GetFrame();
   if (!frame)
     return true;
   return frame->IsVisibleConsideringAncestors(nsIFrame::VISIBILITY_CROSS_CHROME_CONTENT_BOUNDARY);
 }
 nsresult
 PresShell::GetAgentStyleSheets(nsCOMArray<nsIStyleSheet>& aSheets)
 {
   aSheets.Clear();
   int32_t sheetCount = mStyleSet->SheetCount(nsStyleSet::eAgentSheet);
   for (int32_t i = 0; i < sheetCount; ++i) {
     nsIStyleSheet *sheet = mStyleSet->StyleSheetAt(nsStyleSet::eAgentSheet, i);
     if (!aSheets.AppendObject(sheet))
       return NS_ERROR_OUT_OF_MEMORY;
   }
   return NS_OK;
 }
 nsresult
 PresShell::SetAgentStyleSheets(const nsCOMArray<nsIStyleSheet>& aSheets)
 {
   return mStyleSet->ReplaceSheets(nsStyleSet::eAgentSheet, aSheets);
 }
 nsresult
 PresShell::AddOverrideStyleSheet(nsIStyleSheet *aSheet)
 {
   return mStyleSet->PrependStyleSheet(nsStyleSet::eOverrideSheet, aSheet);
 }
 nsresult
 PresShell::RemoveOverrideStyleSheet(nsIStyleSheet *aSheet)
 {
   return mStyleSet->RemoveStyleSheet(nsStyleSet::eOverrideSheet, aSheet);
 }
 static void
 FreezeElement(nsIContent *aContent, void * /* unused */)
 {
   nsCOMPtr<nsIObjectLoadingContent> olc(do_QueryInterface(aContent));
   if (olc) {
     olc->StopPluginInstance();
   }
 }
 static bool
 FreezeSubDocument(nsIDocument *aDocument, void *aData)
 {
   nsIPresShell *shell = aDocument->GetShell();
   if (shell)
     shell->Freeze();
   return true;
 }
 void
 PresShell::Freeze()
 {
   mUpdateImageVisibilityEvent.Revoke();
   MaybeReleaseCapturingContent();
   mDocument->EnumerateFreezableElements(FreezeElement, nullptr);
   if (mCaret) {
     mCaret->SetCaretVisible(false);
   }
   mPaintingSuppressed = true;
   if (mDocument) {
     mDocument->EnumerateSubDocuments(FreezeSubDocument, nullptr);
   }
   nsPresContext* presContext = GetPresContext();
   if (presContext &&
       presContext->RefreshDriver()->PresContext() == presContext) {
     presContext->RefreshDriver()->Freeze();
   }
   mFrozen = true;
   if (mDocument) {
     UpdateImageLockingState();
   }
 }
 void
 PresShell::FireOrClearDelayedEvents(bool aFireEvents)
 {
   mNoDelayedMouseEvents = false;
   mNoDelayedKeyEvents = false;
   if (!aFireEvents) {
     mDelayedEvents.Clear();
     return;
   }
   if (mDocument) {
     nsCOMPtr<nsIDocument> doc = mDocument;
     while (!mIsDestroying && mDelayedEvents.Length() &&
            !doc->EventHandlingSuppressed()) {
       nsAutoPtr<DelayedEvent> ev(mDelayedEvents[0].forget());
       mDelayedEvents.RemoveElementAt(0);
       ev->Dispatch();
     }
     if (!doc->EventHandlingSuppressed()) {
       mDelayedEvents.Clear();
     }
   }
 }
 static void
 ThawElement(nsIContent *aContent, void *aShell)
 {
   nsCOMPtr<nsIObjectLoadingContent> olc(do_QueryInterface(aContent));
   if (olc) {
     olc->AsyncStartPluginInstance();
   }
 }
 static bool
 ThawSubDocument(nsIDocument *aDocument, void *aData)
 {
   nsIPresShell *shell = aDocument->GetShell();
   if (shell)
     shell->Thaw();
   return true;
 }
 void
 PresShell::Thaw()
 {
   nsPresContext* presContext = GetPresContext();
   if (presContext &&
       presContext->RefreshDriver()->PresContext() == presContext) {
     presContext->RefreshDriver()->Thaw();
   }
   mDocument->EnumerateFreezableElements(ThawElement, this);
   if (mDocument)
     mDocument->EnumerateSubDocuments(ThawSubDocument, nullptr);
   // Get the activeness of our presshell, as this might have changed
   // while we were in the bfcache
   QueryIsActive();
   // We're now unfrozen
   mFrozen = false;
   UpdateImageLockingState();
   UnsuppressPainting();
 }
 //--------------------------------------------------------
 // Start of protected and private methods on the PresShell
 //--------------------------------------------------------
 void
 PresShell::MaybeScheduleReflow()
 {
   ASSERT_REFLOW_SCHEDULED_STATE();
   if (mReflowScheduled || mIsDestroying || mIsReflowing ||
       mDirtyRoots.Length() == 0)
     return;
   if (!mPresContext->HasPendingInterrupt() || !ScheduleReflowOffTimer()) {
     ScheduleReflow();
   }
   ASSERT_REFLOW_SCHEDULED_STATE();
 }
 void
 PresShell::ScheduleReflow()
 {
   NS_PRECONDITION(!mReflowScheduled, "Why are we trying to schedule a reflow?");
   ASSERT_REFLOW_SCHEDULED_STATE();
   if (GetPresContext()->RefreshDriver()->AddLayoutFlushObserver(this)) {
     mReflowScheduled = true;
   }
   ASSERT_REFLOW_SCHEDULED_STATE();
 }
 nsresult
 PresShell::DidCauseReflow()
 {
   NS_ASSERTION(mChangeNestCount != 0, "Unexpected call to DidCauseReflow()");
   --mChangeNestCount;
   nsContentUtils::RemoveScriptBlocker();
   return NS_OK;
 }
 void
 PresShell::WillDoReflow()
 {
   // We just reflowed, tell the caret that its frame might have moved.
   // XXXbz that comment makes no sense
   if (mCaret) {
     mCaret->InvalidateOutsideCaret();
   }
   mPresContext->FlushUserFontSet();
   mFrameConstructor->BeginUpdate();
   mLastReflowStart = GetPerformanceNow();
 }
 void
 PresShell::DidDoReflow(bool aInterruptible, bool aWasInterrupted)
 {
   mFrameConstructor->EndUpdate();
   HandlePostedReflowCallbacks(aInterruptible);
   nsCOMPtr<nsIDocShell> docShell = mPresContext->GetDocShell();
   if (docShell) {
     DOMHighResTimeStamp now = GetPerformanceNow();
     docShell->NotifyReflowObservers(aInterruptible, mLastReflowStart, now);
   }
   if (sSynthMouseMove) {
     SynthesizeMouseMove(false);
   }
   if (mCaret) {
     // Update the caret's position now to account for any changes created by
     // the reflow.
     mCaret->InvalidateOutsideCaret();
     mCaret->UpdateCaretPosition();
   }
   if (!aWasInterrupted) {
     ClearReflowOnZoomPending();
   }
 }
 DOMHighResTimeStamp
 PresShell::GetPerformanceNow()
 {
   DOMHighResTimeStamp now = 0;
   nsPIDOMWindow* window = mDocument->GetInnerWindow();
   if (window) {
     nsPerformance* perf = window->GetPerformance();
     if (perf) {
       now = perf->Now();
     }
   }
   return now;
 }
 static PLDHashOperator
 MarkFramesDirtyToRoot(nsPtrHashKey<nsIFrame>* p, void* closure)
 {
   nsIFrame* target = static_cast<nsIFrame*>(closure);
   for (nsIFrame* f = p->GetKey(); f && !NS_SUBTREE_DIRTY(f);
        f = f->GetParent()) {
     f->AddStateBits(NS_FRAME_HAS_DIRTY_CHILDREN);
     if (f == target) {
       break;
     }
   }
   return PL_DHASH_NEXT;
 }
 void
 PresShell::sReflowContinueCallback(nsITimer* aTimer, void* aPresShell)
 {
   nsRefPtr<PresShell> self = static_cast<PresShell*>(aPresShell);
   NS_PRECONDITION(aTimer == self->mReflowContinueTimer, "Unexpected timer");
   self->mReflowContinueTimer = nullptr;
   self->ScheduleReflow();
 }
 bool
 PresShell::ScheduleReflowOffTimer()
 {
   NS_PRECONDITION(!mReflowScheduled, "Shouldn't get here");
   ASSERT_REFLOW_SCHEDULED_STATE();
   if (!mReflowContinueTimer) {
     mReflowContinueTimer = do_CreateInstance("@mozilla.org/timer;1");
     if (!mReflowContinueTimer ||
         NS_FAILED(mReflowContinueTimer->
                     InitWithFuncCallback(sReflowContinueCallback, this, 30,
                                          nsITimer::TYPE_ONE_SHOT))) {
       return false;
     }
   }
   return true;
 }
 bool
 PresShell::DoReflow(nsIFrame* target, bool aInterruptible)
 {
   if (mIsZombie) {
     return true;
   }
   gfxTextPerfMetrics* tp = mPresContext->GetTextPerfMetrics();
   TimeStamp timeStart;
   if (tp) {
     tp->Accumulate();
     tp->reflowCount++;
     timeStart = TimeStamp::Now();
   }
   target->SchedulePaint();
   nsIFrame *parent = nsLayoutUtils::GetCrossDocParentFrame(target);
   while (parent) {
     nsSVGEffects::InvalidateDirectRenderingObservers(parent);
     parent = nsLayoutUtils::GetCrossDocParentFrame(parent);
   }
   nsAutoCString docURL("N/A");
   nsIURI *uri = mDocument->GetDocumentURI();
   if (uri)
     uri->GetSpec(docURL);
   PROFILER_LABEL_PRINTF("layout", "DoReflow", "(%s)", docURL.get());
   if (mReflowContinueTimer) {
     mReflowContinueTimer->Cancel();
     mReflowContinueTimer = nullptr;
   }
   nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
   nsRefPtr<nsRenderingContext> rcx = CreateReferenceRenderingContext();
 #ifdef DEBUG
   mCurrentReflowRoot = target;
 #endif
   target->WillReflow(mPresContext);
   // If the target frame is the root of the frame hierarchy, then
   // use all the available space. If it's simply a `reflow root',
   // then use the target frame's size as the available space.
   nsSize size;
   if (target == rootFrame) {
      size = mPresContext->GetVisibleArea().Size();
   } else {
      size = target->GetSize();
   }
   NS_ASSERTION(!target->GetNextInFlow() && !target->GetPrevInFlow(),
                "reflow roots should never split");
   // Don't pass size directly to the reflow state, since a
   // constrained height implies page/column breaking.
   nsSize reflowSize(size.width, NS_UNCONSTRAINEDSIZE);
   nsHTMLReflowState reflowState(mPresContext, target, rcx, reflowSize,
                                 nsHTMLReflowState::CALLER_WILL_INIT);
   if (rootFrame == target) {
     reflowState.Init(mPresContext);
     // When the root frame is being reflowed with unconstrained height
     // (which happens when we're called from
     // nsDocumentViewer::SizeToContent), we're effectively doing a
     // vertical resize, since it changes the meaning of percentage
     // heights even if no heights actually changed.  The same applies
     // when we reflow again after that computation.  This is an unusual
     // case, and isn't caught by nsHTMLReflowState::InitResizeFlags.
     bool hasUnconstrainedHeight = size.height == NS_UNCONSTRAINEDSIZE;
     if (hasUnconstrainedHeight || mLastRootReflowHadUnconstrainedHeight) {
       reflowState.mFlags.mVResize = true;
     }
     mLastRootReflowHadUnconstrainedHeight = hasUnconstrainedHeight;
   } else {
     // Initialize reflow state with current used border and padding,
     // in case this was set specially by the parent frame when the reflow root
     // was reflowed by its parent.
     nsMargin currentBorder = target->GetUsedBorder();
     nsMargin currentPadding = target->GetUsedPadding();
     reflowState.Init(mPresContext, -1, -1, &currentBorder, &currentPadding);
   }
   // fix the computed height
   NS_ASSERTION(reflowState.ComputedPhysicalMargin() == nsMargin(0, 0, 0, 0),
                "reflow state should not set margin for reflow roots");
   if (size.height != NS_UNCONSTRAINEDSIZE) {
     nscoord computedHeight =
       size.height - reflowState.ComputedPhysicalBorderPadding().TopBottom();
     computedHeight = std::max(computedHeight, 0);
     reflowState.SetComputedHeight(computedHeight);
   }
   NS_ASSERTION(reflowState.ComputedWidth() ==
                  size.width -
                    reflowState.ComputedPhysicalBorderPadding().LeftRight(),
                "reflow state computed incorrect width");
   mPresContext->ReflowStarted(aInterruptible);
   mIsReflowing = true;
   nsReflowStatus status;
   nsHTMLReflowMetrics desiredSize(reflowState);
   target->Reflow(mPresContext, desiredSize, reflowState, status);
   // If an incremental reflow is initiated at a frame other than the
   // root frame, then its desired size had better not change!  If it's
   // initiated at the root, then the size better not change unless its
   // height was unconstrained to start with.
   nsRect boundsRelativeToTarget = nsRect(0, 0, desiredSize.Width(), desiredSize.Height());
   NS_ASSERTION((target == rootFrame && size.height == NS_UNCONSTRAINEDSIZE) ||
                (desiredSize.Width() == size.width &&
                 desiredSize.Height() == size.height),
                "non-root frame's desired size changed during an "
                "incremental reflow");
   NS_ASSERTION(target == rootFrame ||
                desiredSize.VisualOverflow().IsEqualInterior(boundsRelativeToTarget),
                "non-root reflow roots must not have visible overflow");
   NS_ASSERTION(target == rootFrame ||
                desiredSize.ScrollableOverflow().IsEqualEdges(boundsRelativeToTarget),
                "non-root reflow roots must not have scrollable overflow");
   NS_ASSERTION(status == NS_FRAME_COMPLETE,
                "reflow roots should never split");
   target->SetSize(boundsRelativeToTarget.Size());
   // Always use boundsRelativeToTarget here, not desiredSize.GetVisualOverflowArea(),
   // because for root frames (where they could be different, since root frames
   // are allowed to have overflow) the root view bounds need to match the
   // viewport bounds; the view manager "window dimensions" code depends on it.
   nsContainerFrame::SyncFrameViewAfterReflow(mPresContext, target,
                                              target->GetView(),
                                              boundsRelativeToTarget);
   nsContainerFrame::SyncWindowProperties(mPresContext, target,
                                          target->GetView(), rcx);
   target->DidReflow(mPresContext, nullptr, nsDidReflowStatus::FINISHED);
   if (target == rootFrame && size.height == NS_UNCONSTRAINEDSIZE) {
     mPresContext->SetVisibleArea(boundsRelativeToTarget);
   }
 #ifdef DEBUG
   mCurrentReflowRoot = nullptr;
 #endif
   NS_ASSERTION(mPresContext->HasPendingInterrupt() ||
                mFramesToDirty.Count() == 0,
                "Why do we need to dirty anything if not interrupted?");
   mIsReflowing = false;
   bool interrupted = mPresContext->HasPendingInterrupt();
   if (interrupted) {
     // Make sure target gets reflowed again.
     mFramesToDirty.EnumerateEntries(&MarkFramesDirtyToRoot, target);
     NS_ASSERTION(NS_SUBTREE_DIRTY(target), "Why is the target not dirty?");
     mDirtyRoots.AppendElement(target);
     mDocument->SetNeedLayoutFlush();
     // Clear mFramesToDirty after we've done the NS_SUBTREE_DIRTY(target)
     // assertion so that if it fails it's easier to see what's going on.
 #ifdef NOISY_INTERRUPTIBLE_REFLOW
     printf("mFramesToDirty.Count() == %u\n", mFramesToDirty.Count());
 #endif /* NOISY_INTERRUPTIBLE_REFLOW */
     mFramesToDirty.Clear();
     // Any FlushPendingNotifications with interruptible reflows
     // should be suppressed now. We don't want to do extra reflow work
     // before our reflow event happens.
     mSuppressInterruptibleReflows = true;
     MaybeScheduleReflow();
   }
 #ifdef PR_LOGGING
   // dump text perf metrics for reflows with significant text processing
   if (tp) {
     if (tp->current.numChars > 100) {
       TimeDuration reflowTime = TimeStamp::Now() - timeStart;
       LogTextPerfStats(tp, this, tp->current,
                        reflowTime.ToMilliseconds(), eLog_reflow, nullptr);
     }
     tp->Accumulate();
   }
 #endif
   return !interrupted;
 }
 #ifdef DEBUG
 void
 PresShell::DoVerifyReflow()
 {
   if (GetVerifyReflowEnable()) {
     // First synchronously render what we have so far so that we can
     // see it.
     nsView* rootView = mViewManager->GetRootView();
     mViewManager->InvalidateView(rootView);
     FlushPendingNotifications(Flush_Layout);
     mInVerifyReflow = true;
     bool ok = VerifyIncrementalReflow();
     mInVerifyReflow = false;
     if (VERIFY_REFLOW_ALL & gVerifyReflowFlags) {
       printf("ProcessReflowCommands: finished (%s)\n",
              ok ? "ok" : "failed");
     }
     if (!mDirtyRoots.IsEmpty()) {
       printf("XXX yikes! reflow commands queued during verify-reflow\n");
     }
   }
 }
 #endif
 // used with Telemetry metrics
 #define NS_LONG_REFLOW_TIME_MS    5000
 bool
 PresShell::ProcessReflowCommands(bool aInterruptible)
 {
   if (mDirtyRoots.IsEmpty() && !mShouldUnsuppressPainting) {
     // Nothing to do; bail out
     return true;
   }
   mozilla::TimeStamp timerStart = mozilla::TimeStamp::Now();
   bool interrupted = false;
   if (!mDirtyRoots.IsEmpty()) {
 #ifdef DEBUG
     if (VERIFY_REFLOW_DUMP_COMMANDS & gVerifyReflowFlags) {
       printf("ProcessReflowCommands: begin incremental reflow\n");
     }
 #endif
     // If reflow is interruptible, then make a note of our deadline.
     const PRIntervalTime deadline = aInterruptible
         ? PR_IntervalNow() + PR_MicrosecondsToInterval(gMaxRCProcessingTime)
         : (PRIntervalTime)0;
     // Scope for the reflow entry point
     {
       nsAutoScriptBlocker scriptBlocker;
       WillDoReflow();
       AUTO_LAYOUT_PHASE_ENTRY_POINT(GetPresContext(), Reflow);
       nsViewManager::AutoDisableRefresh refreshBlocker(mViewManager);
       do {
         // Send an incremental reflow notification to the target frame.
         int32_t idx = mDirtyRoots.Length() - 1;
         nsIFrame *target = mDirtyRoots[idx];
         mDirtyRoots.RemoveElementAt(idx);
         if (!NS_SUBTREE_DIRTY(target)) {
           // It's not dirty anymore, which probably means the notification
           // was posted in the middle of a reflow (perhaps with a reflow
           // root in the middle).  Don't do anything.
           continue;
         }
         interrupted = !DoReflow(target, aInterruptible);
         // Keep going until we're out of reflow commands, or we've run
         // past our deadline, or we're interrupted.
       } while (!interrupted && !mDirtyRoots.IsEmpty() &&
                (!aInterruptible || PR_IntervalNow() < deadline));
       interrupted = !mDirtyRoots.IsEmpty();
     }
     // Exiting the scriptblocker might have killed us
     if (!mIsDestroying) {
       DidDoReflow(aInterruptible, interrupted);
     }
     // DidDoReflow might have killed us
     if (!mIsDestroying) {
 #ifdef DEBUG
       if (VERIFY_REFLOW_DUMP_COMMANDS & gVerifyReflowFlags) {
         printf("\nPresShell::ProcessReflowCommands() finished: this=%p\n",
                (void*)this);
       }
       DoVerifyReflow();
 #endif
       // If any new reflow commands were enqueued during the reflow, schedule
       // another reflow event to process them.  Note that we want to do this
       // after DidDoReflow(), since that method can change whether there are
       // dirty roots around by flushing, and there's no point in posting a
       // reflow event just to have the flush revoke it.
       if (!mDirtyRoots.IsEmpty()) {
         MaybeScheduleReflow();
         // And tell our document that we might need flushing
         mDocument->SetNeedLayoutFlush();
       }
     }
   }
   if (!mIsDestroying && mShouldUnsuppressPainting &&
       mDirtyRoots.IsEmpty()) {
     // We only unlock if we're out of reflows.  It's pointless
     // to unlock if reflows are still pending, since reflows
     // are just going to thrash the frames around some more.  By
     // waiting we avoid an overeager "jitter" effect.
     mShouldUnsuppressPainting = false;
     UnsuppressAndInvalidate();
   }
   if (mDocument->GetRootElement()) {
     TimeDuration elapsed = TimeStamp::Now() - timerStart;
     int32_t intElapsed = int32_t(elapsed.ToMilliseconds());
     Telemetry::ID id;
     if (mDocument->GetRootElement()->IsXUL()) {
       id = mIsActive
         ? Telemetry::XUL_FOREGROUND_REFLOW_MS
         : Telemetry::XUL_BACKGROUND_REFLOW_MS;
     } else {
       id = mIsActive
         ? Telemetry::HTML_FOREGROUND_REFLOW_MS_2
         : Telemetry::HTML_BACKGROUND_REFLOW_MS_2;
     }
     Telemetry::Accumulate(id, intElapsed);
     if (intElapsed > NS_LONG_REFLOW_TIME_MS) {
       Telemetry::Accumulate(Telemetry::LONG_REFLOW_INTERRUPTIBLE,
                             aInterruptible ? 1 : 0);
     }
   }
   return !interrupted;
 }
 void
 PresShell::WindowSizeMoveDone()
 {
   if (mPresContext) {
     EventStateManager::ClearGlobalActiveContent(nullptr);
     ClearMouseCapture(nullptr);
   }
 }
 #ifdef MOZ_XUL
 /*
  * It's better to add stuff to the |DidSetStyleContext| method of the
  * relevant frames than adding it here.  These methods should (ideally,
  * anyway) go away.
  */
 // Return value says whether to walk children.
 typedef bool (* frameWalkerFn)(nsIFrame *aFrame, void *aClosure);
 static bool
 ReResolveMenusAndTrees(nsIFrame *aFrame, void *aClosure)
 {
   // Trees have a special style cache that needs to be flushed when
   // the theme changes.
   nsTreeBodyFrame *treeBody = do_QueryFrame(aFrame);
   if (treeBody)
     treeBody->ClearStyleAndImageCaches();
   // We deliberately don't re-resolve style on a menu's popup
   // sub-content, since doing so slows menus to a crawl.  That means we
   // have to special-case them on a skin switch, and ensure that the
   // popup frames just get destroyed completely.
   nsMenuFrame* menu = do_QueryFrame(aFrame);
   if (menu)
     menu->CloseMenu(true);
   return true;
 }
 static bool
 ReframeImageBoxes(nsIFrame *aFrame, void *aClosure)
 {
   nsStyleChangeList *list = static_cast<nsStyleChangeList*>(aClosure);
   if (aFrame->GetType() == nsGkAtoms::imageBoxFrame) {
     list->AppendChange(aFrame, aFrame->GetContent(),
                        NS_STYLE_HINT_FRAMECHANGE);
     return false; // don't walk descendants
   }
   return true; // walk descendants
 }
 static void
 WalkFramesThroughPlaceholders(nsPresContext *aPresContext, nsIFrame *aFrame,
                               frameWalkerFn aFunc, void *aClosure)
 {
   bool walkChildren = (*aFunc)(aFrame, aClosure);
   if (!walkChildren)
     return;
   nsIFrame::ChildListIterator lists(aFrame);
   for (; !lists.IsDone(); lists.Next()) {
     nsFrameList::Enumerator childFrames(lists.CurrentList());
     for (; !childFrames.AtEnd(); childFrames.Next()) {
       nsIFrame* child = childFrames.get();
       if (!(child->GetStateBits() & NS_FRAME_OUT_OF_FLOW)) {
         // only do frames that are in flow, and recur through the
         // out-of-flows of placeholders.
         WalkFramesThroughPlaceholders(aPresContext,
                                       nsPlaceholderFrame::GetRealFrameFor(child),
                                       aFunc, aClosure);
       }
     }
   }
 }
 #endif
 NS_IMETHODIMP
 PresShell::Observe(nsISupports* aSubject,
                    const char* aTopic,
                    const char16_t* aData)
 {
 #ifdef MOZ_XUL
   if (!nsCRT::strcmp(aTopic, "chrome-flush-skin-caches")) {
     nsIFrame *rootFrame = mFrameConstructor->GetRootFrame();
     // Need to null-check because "chrome-flush-skin-caches" can happen
     // at interesting times during startup.
     if (rootFrame) {
       NS_ASSERTION(mViewManager, "View manager must exist");
       nsWeakFrame weakRoot(rootFrame);
       // Have to make sure that the content notifications are flushed before we
       // start messing with the frame model; otherwise we can get content doubling.
       mDocument->FlushPendingNotifications(Flush_ContentAndNotify);
       if (weakRoot.IsAlive()) {
         WalkFramesThroughPlaceholders(mPresContext, rootFrame,
                                       &ReResolveMenusAndTrees, nullptr);
         // Because "chrome:" URL equality is messy, reframe image box
         // frames (hack!).
         nsStyleChangeList changeList;
         WalkFramesThroughPlaceholders(mPresContext, rootFrame,
                                       ReframeImageBoxes, &changeList);
         // Mark ourselves as not safe to flush while we're doing frame
         // construction.
         {
           nsAutoScriptBlocker scriptBlocker;
           ++mChangeNestCount;
           RestyleManager* restyleManager = mPresContext->RestyleManager();
           restyleManager->ProcessRestyledFrames(changeList);
           restyleManager->FlushOverflowChangedTracker();
           --mChangeNestCount;
         }
       }
     }
     return NS_OK;
   }
 #endif
   if (!nsCRT::strcmp(aTopic, "agent-sheet-added") && mStyleSet) {
     AddAgentSheet(aSubject);
     return NS_OK;
   }
   if (!nsCRT::strcmp(aTopic, "user-sheet-added") && mStyleSet) {
     AddUserSheet(aSubject);
     return NS_OK;
   }
   if (!nsCRT::strcmp(aTopic, "author-sheet-added") && mStyleSet) {
     AddAuthorSheet(aSubject);
     return NS_OK;
   }
   if (!nsCRT::strcmp(aTopic, "agent-sheet-removed") && mStyleSet) {
     RemoveSheet(nsStyleSet::eAgentSheet, aSubject);
     return NS_OK;
   }
   if (!nsCRT::strcmp(aTopic, "user-sheet-removed") && mStyleSet) {
     RemoveSheet(nsStyleSet::eUserSheet, aSubject);
     return NS_OK;
   }
   if (!nsCRT::strcmp(aTopic, "author-sheet-removed") && mStyleSet) {
     RemoveSheet(nsStyleSet::eDocSheet, aSubject);
     return NS_OK;
   }
   NS_WARNING("unrecognized topic in PresShell::Observe");
   return NS_ERROR_FAILURE;
 }
 bool
 nsIPresShell::AddRefreshObserverInternal(nsARefreshObserver* aObserver,
                                          mozFlushType aFlushType)
 {
   nsPresContext* presContext = GetPresContext();
   return presContext &&
       presContext->RefreshDriver()->AddRefreshObserver(aObserver, aFlushType);
 }
 /* virtual */ bool
 nsIPresShell::AddRefreshObserverExternal(nsARefreshObserver* aObserver,
                                          mozFlushType aFlushType)
 {
   return AddRefreshObserverInternal(aObserver, aFlushType);
 }
 bool
 nsIPresShell::RemoveRefreshObserverInternal(nsARefreshObserver* aObserver,
                                             mozFlushType aFlushType)
 {
   nsPresContext* presContext = GetPresContext();
   return presContext &&
       presContext->RefreshDriver()->RemoveRefreshObserver(aObserver, aFlushType);
 }
 /* virtual */ bool
 nsIPresShell::RemoveRefreshObserverExternal(nsARefreshObserver* aObserver,
                                             mozFlushType aFlushType)
 {
   return RemoveRefreshObserverInternal(aObserver, aFlushType);
 }
 /* virtual */ bool
 nsIPresShell::AddPostRefreshObserver(nsAPostRefreshObserver* aObserver)
 {
   nsPresContext* presContext = GetPresContext();
   if (!presContext) {
     return false;
   }
   presContext->RefreshDriver()->AddPostRefreshObserver(aObserver);
   return true;
 }
 /* virtual */ bool
 nsIPresShell::RemovePostRefreshObserver(nsAPostRefreshObserver* aObserver)
 {
   nsPresContext* presContext = GetPresContext();
   if (!presContext) {
     return false;
   }
   presContext->RefreshDriver()->RemovePostRefreshObserver(aObserver);
   return true;
 }
 //------------------------------------------------------
 // End of protected and private methods on the PresShell
 //------------------------------------------------------
 //------------------------------------------------------------------
 //-- Delayed event Classes Impls
 //------------------------------------------------------------------
 PresShell::DelayedInputEvent::DelayedInputEvent() :
   DelayedEvent(),
   mEvent(nullptr)
 {
 }
 PresShell::DelayedInputEvent::~DelayedInputEvent()
 {
   delete mEvent;
 }
 void
 PresShell::DelayedInputEvent::Dispatch()
 {
   if (!mEvent || !mEvent->widget) {
     return;
   }
   nsCOMPtr<nsIWidget> widget = mEvent->widget;
   nsEventStatus status;
   widget->DispatchEvent(mEvent, status);
 }
 PresShell::DelayedMouseEvent::DelayedMouseEvent(WidgetMouseEvent* aEvent) :
   DelayedInputEvent()
 {
   WidgetMouseEvent* mouseEvent =
     new WidgetMouseEvent(aEvent->mFlags.mIsTrusted,
                          aEvent->message,
                          aEvent->widget,
                          aEvent->reason,
                          aEvent->context);
   mouseEvent->AssignMouseEventData(*aEvent, false);
   mEvent = mouseEvent;
 }
 PresShell::DelayedKeyEvent::DelayedKeyEvent(WidgetKeyboardEvent* aEvent) :
   DelayedInputEvent()
 {
   WidgetKeyboardEvent* keyEvent =
     new WidgetKeyboardEvent(aEvent->mFlags.mIsTrusted,
                             aEvent->message,
                             aEvent->widget);
   keyEvent->AssignKeyEventData(*aEvent, false);
   keyEvent->mFlags.mIsSynthesizedForTests = aEvent->mFlags.mIsSynthesizedForTests;
   mEvent = keyEvent;
 }
 // Start of DEBUG only code
 #ifdef DEBUG
 static void
 LogVerifyMessage(nsIFrame* k1, nsIFrame* k2, const char* aMsg)
 {
   nsAutoString n1, n2;
   if (k1) {
     k1->GetFrameName(n1);
   } else {
     n1.Assign(NS_LITERAL_STRING("(null)"));
   }
   if (k2) {
     k2->GetFrameName(n2);
   } else {
     n2.Assign(NS_LITERAL_STRING("(null)"));
   }
   printf("verifyreflow: %s %p != %s %p  %s\n",
          NS_LossyConvertUTF16toASCII(n1).get(), (void*)k1,
          NS_LossyConvertUTF16toASCII(n2).get(), (void*)k2, aMsg);
 }
 static void
 LogVerifyMessage(nsIFrame* k1, nsIFrame* k2, const char* aMsg,
                  const nsRect& r1, const nsRect& r2)
 {
   printf("VerifyReflow Error:\n");
   nsAutoString name;
   if (k1) {
     k1->GetFrameName(name);
     printf("  %s %p ", NS_LossyConvertUTF16toASCII(name).get(), (void*)k1);
   }
   printf("{%d, %d, %d, %d} != \n", r1.x, r1.y, r1.width, r1.height);
   if (k2) {
     k2->GetFrameName(name);
     printf("  %s %p ", NS_LossyConvertUTF16toASCII(name).get(), (void*)k2);
   }
   printf("{%d, %d, %d, %d}\n  %s\n",
          r2.x, r2.y, r2.width, r2.height, aMsg);
 }
 static void
 LogVerifyMessage(nsIFrame* k1, nsIFrame* k2, const char* aMsg,
                  const nsIntRect& r1, const nsIntRect& r2)
 {
   printf("VerifyReflow Error:\n");
   nsAutoString name;
   if (k1) {
     k1->GetFrameName(name);
     printf("  %s %p ", NS_LossyConvertUTF16toASCII(name).get(), (void*)k1);
   }
   printf("{%d, %d, %d, %d} != \n", r1.x, r1.y, r1.width, r1.height);
   if (k2) {
     k2->GetFrameName(name);
     printf("  %s %p ", NS_LossyConvertUTF16toASCII(name).get(), (void*)k2);
   }
   printf("{%d, %d, %d, %d}\n  %s\n",
          r2.x, r2.y, r2.width, r2.height, aMsg);
 }
 static bool
 CompareTrees(nsPresContext* aFirstPresContext, nsIFrame* aFirstFrame,
              nsPresContext* aSecondPresContext, nsIFrame* aSecondFrame)
 {
   if (!aFirstPresContext || !aFirstFrame || !aSecondPresContext || !aSecondFrame)
     return true;
   // XXX Evil hack to reduce false positives; I can't seem to figure
   // out how to flush scrollbar changes correctly
   //if (aFirstFrame->GetType() == nsGkAtoms::scrollbarFrame)
   //  return true;
   bool ok = true;
   nsIFrame::ChildListIterator lists1(aFirstFrame);
   nsIFrame::ChildListIterator lists2(aSecondFrame);
   do {
     const nsFrameList& kids1 = !lists1.IsDone() ? lists1.CurrentList() : nsFrameList();
     const nsFrameList& kids2 = !lists2.IsDone() ? lists2.CurrentList() : nsFrameList();
     int32_t l1 = kids1.GetLength();
     int32_t l2 = kids2.GetLength();;
     if (l1 != l2) {
       ok = false;
       LogVerifyMessage(kids1.FirstChild(), kids2.FirstChild(),
                        "child counts don't match: ");
       printf("%d != %d\n", l1, l2);
       if (0 == (VERIFY_REFLOW_ALL & gVerifyReflowFlags)) {
         break;
       }
     }
     nsIntRect r1, r2;
     nsView* v1, *v2;
     for (nsFrameList::Enumerator e1(kids1), e2(kids2);
          ;
          e1.Next(), e2.Next()) {
       nsIFrame* k1 = e1.get();
       nsIFrame* k2 = e2.get();
       if (((nullptr == k1) && (nullptr != k2)) ||
           ((nullptr != k1) && (nullptr == k2))) {
         ok = false;
         LogVerifyMessage(k1, k2, "child lists are different\n");
         break;
       }
       else if (nullptr != k1) {
         // Verify that the frames are the same size
         if (!k1->GetRect().IsEqualInterior(k2->GetRect())) {
           ok = false;
           LogVerifyMessage(k1, k2, "(frame rects)", k1->GetRect(), k2->GetRect());
         }
         // Make sure either both have views or neither have views; if they
         // do have views, make sure the views are the same size. If the
         // views have widgets, make sure they both do or neither does. If
         // they do, make sure the widgets are the same size.
         v1 = k1->GetView();
         v2 = k2->GetView();
         if (((nullptr == v1) && (nullptr != v2)) ||
             ((nullptr != v1) && (nullptr == v2))) {
           ok = false;
           LogVerifyMessage(k1, k2, "child views are not matched\n");
         }
         else if (nullptr != v1) {
           if (!v1->GetBounds().IsEqualInterior(v2->GetBounds())) {
             LogVerifyMessage(k1, k2, "(view rects)", v1->GetBounds(), v2->GetBounds());
           }
           nsIWidget* w1 = v1->GetWidget();
           nsIWidget* w2 = v2->GetWidget();
           if (((nullptr == w1) && (nullptr != w2)) ||
               ((nullptr != w1) && (nullptr == w2))) {
             ok = false;
             LogVerifyMessage(k1, k2, "child widgets are not matched\n");
           }
           else if (nullptr != w1) {
             w1->GetBounds(r1);
             w2->GetBounds(r2);
             if (!r1.IsEqualEdges(r2)) {
               LogVerifyMessage(k1, k2, "(widget rects)", r1, r2);
             }
           }
         }
         if (!ok && (0 == (VERIFY_REFLOW_ALL & gVerifyReflowFlags))) {
           break;
         }
         // XXX Should perhaps compare their float managers.
         // Compare the sub-trees too
         if (!CompareTrees(aFirstPresContext, k1, aSecondPresContext, k2)) {
           ok = false;
           if (0 == (VERIFY_REFLOW_ALL & gVerifyReflowFlags)) {
             break;
           }
         }
       }
       else {
         break;
       }
     }
     if (!ok && (0 == (VERIFY_REFLOW_ALL & gVerifyReflowFlags))) {
       break;
     }
     lists1.Next();
     lists2.Next();
     if (lists1.IsDone() != lists2.IsDone() ||
         (!lists1.IsDone() && lists1.CurrentID() != lists2.CurrentID())) {
       if (0 == (VERIFY_REFLOW_ALL & gVerifyReflowFlags)) {
         ok = false;
       }
       LogVerifyMessage(kids1.FirstChild(), kids2.FirstChild(),
                        "child list names are not matched: ");
       fprintf(stdout, "%s != %s\n",
               !lists1.IsDone() ? mozilla::layout::ChildListName(lists1.CurrentID()) : "(null)",
               !lists2.IsDone() ? mozilla::layout::ChildListName(lists2.CurrentID()) : "(null)");
       break;
     }
   } while (ok && !lists1.IsDone());
   return ok;
 }
 #endif
 #if 0
 static nsIFrame*
 FindTopFrame(nsIFrame* aRoot)
 {
   if (aRoot) {
     nsIContent* content = aRoot->GetContent();
     if (content) {
       nsIAtom* tag;
       content->GetTag(tag);
       if (nullptr != tag) {
         NS_RELEASE(tag);
         return aRoot;
       }
     }
     // Try one of the children
     nsIFrame* kid = aRoot->GetFirstPrincipalChild();
     while (nullptr != kid) {
       nsIFrame* result = FindTopFrame(kid);
       if (nullptr != result) {
         return result;
       }
       kid = kid->GetNextSibling();
     }
   }
   return nullptr;
 }
 #endif
 #ifdef DEBUG
 nsStyleSet*
 PresShell::CloneStyleSet(nsStyleSet* aSet)
 {
   nsStyleSet *clone = new nsStyleSet();
   int32_t i, n = aSet->SheetCount(nsStyleSet::eOverrideSheet);
   for (i = 0; i < n; i++) {
     nsIStyleSheet* ss = aSet->StyleSheetAt(nsStyleSet::eOverrideSheet, i);
     if (ss)
       clone->AppendStyleSheet(nsStyleSet::eOverrideSheet, ss);
   }
   // The document expects to insert document stylesheets itself
 #if 0
   n = aSet->SheetCount(nsStyleSet::eDocSheet);
   for (i = 0; i < n; i++) {
     nsIStyleSheet* ss = aSet->StyleSheetAt(nsStyleSet::eDocSheet, i);
     if (ss)
       clone->AddDocStyleSheet(ss, mDocument);
   }
 #endif
   n = aSet->SheetCount(nsStyleSet::eUserSheet);
   for (i = 0; i < n; i++) {
     nsIStyleSheet* ss = aSet->StyleSheetAt(nsStyleSet::eUserSheet, i);
     if (ss)
       clone->AppendStyleSheet(nsStyleSet::eUserSheet, ss);
   }
   n = aSet->SheetCount(nsStyleSet::eAgentSheet);
   for (i = 0; i < n; i++) {
     nsIStyleSheet* ss = aSet->StyleSheetAt(nsStyleSet::eAgentSheet, i);
     if (ss)
       clone->AppendStyleSheet(nsStyleSet::eAgentSheet, ss);
   }
   return clone;
 }
 #ifdef DEBUG_Eli
 static nsresult
 DumpToPNG(nsIPresShell* shell, nsAString& name) {
   int32_t width=1000, height=1000;
   nsRect r(0, 0, shell->GetPresContext()->DevPixelsToAppUnits(width),
                  shell->GetPresContext()->DevPixelsToAppUnits(height));
   nsRefPtr<gfxImageSurface> imgSurface =
      new gfxImageSurface(gfxIntSize(width, height),
                          gfxImageFormat::ARGB32);
   nsRefPtr<gfxContext> imgContext = new gfxContext(imgSurface);
   nsRefPtr<gfxASurface> surface =
     gfxPlatform::GetPlatform()->
     CreateOffscreenSurface(IntSize(width, height),
       gfxASurface::ContentFromFormat(gfxImageFormat::ARGB32));
   NS_ENSURE_TRUE(surface, NS_ERROR_OUT_OF_MEMORY);
   nsRefPtr<gfxContext> context = new gfxContext(surface);
   shell->RenderDocument(r, 0, NS_RGB(255, 255, 0), context);
   imgContext->DrawSurface(surface, gfxSize(width, height));
   nsCOMPtr<imgIEncoder> encoder = do_CreateInstance("@mozilla.org/image/encoder;2?type=image/png");
   NS_ENSURE_TRUE(encoder, NS_ERROR_FAILURE);
   encoder->InitFromData(imgSurface->Data(), imgSurface->Stride() * height,
                         width, height, imgSurface->Stride(),
                         imgIEncoder::INPUT_FORMAT_HOSTARGB, EmptyString());
   // XXX not sure if this is the right way to write to a file
   nsCOMPtr<nsIFile> file = do_CreateInstance("@mozilla.org/file/local;1");
   NS_ENSURE_TRUE(file, NS_ERROR_FAILURE);
   rv = file->InitWithPath(name);
   NS_ENSURE_SUCCESS(rv, rv);
   uint64_t length64;
   rv = encoder->Available(&length64);
   NS_ENSURE_SUCCESS(rv, rv);
   if (length64 > UINT32_MAX)
     return NS_ERROR_FILE_TOO_BIG;
   uint32_t length = (uint32_t)length64;
   nsCOMPtr<nsIOutputStream> outputStream;
   rv = NS_NewLocalFileOutputStream(getter_AddRefs(outputStream), file);
   NS_ENSURE_SUCCESS(rv, rv);
   nsCOMPtr<nsIOutputStream> bufferedOutputStream;
   rv = NS_NewBufferedOutputStream(getter_AddRefs(bufferedOutputStream),
                                   outputStream, length);
   NS_ENSURE_SUCCESS(rv, rv);
   uint32_t numWritten;
   rv = bufferedOutputStream->WriteFrom(encoder, length, &numWritten);
   NS_ENSURE_SUCCESS(rv, rv);
   return NS_OK;
 }
 #endif
 // After an incremental reflow, we verify the correctness by doing a
 // full reflow into a fresh frame tree.
 bool
 PresShell::VerifyIncrementalReflow()
 {
    if (VERIFY_REFLOW_NOISY & gVerifyReflowFlags) {
      printf("Building Verification Tree...\n");
    }
   // Create a presentation context to view the new frame tree
   nsRefPtr<nsPresContext> cx =
        new nsRootPresContext(mDocument, mPresContext->IsPaginated() ?
                                         nsPresContext::eContext_PrintPreview :
                                         nsPresContext::eContext_Galley);
   NS_ENSURE_TRUE(cx, false);
   nsDeviceContext *dc = mPresContext->DeviceContext();
   nsresult rv = cx->Init(dc);
   NS_ENSURE_SUCCESS(rv, false);
   // Get our scrolling preference
   nsView* rootView = mViewManager->GetRootView();
   NS_ENSURE_TRUE(rootView->HasWidget(), false);
   nsIWidget* parentWidget = rootView->GetWidget();
   // Create a new view manager.
   nsRefPtr<nsViewManager> vm = new nsViewManager();
   NS_ENSURE_TRUE(vm, false);
   rv = vm->Init(dc);
   NS_ENSURE_SUCCESS(rv, false);
   // Create a child window of the parent that is our "root view/window"
   // Create a view
   nsRect tbounds = mPresContext->GetVisibleArea();
   nsView* view = vm->CreateView(tbounds, nullptr);
   NS_ENSURE_TRUE(view, false);
   //now create the widget for the view
   rv = view->CreateWidgetForParent(parentWidget, nullptr, true);
   NS_ENSURE_SUCCESS(rv, false);
   // Setup hierarchical relationship in view manager
   vm->SetRootView(view);
   // Make the new presentation context the same size as our
   // presentation context.
   nsRect r = mPresContext->GetVisibleArea();
   cx->SetVisibleArea(r);
   // Create a new presentation shell to view the document. Use the
   // exact same style information that this document has.
   nsAutoPtr<nsStyleSet> newSet(CloneStyleSet(mStyleSet));
   nsCOMPtr<nsIPresShell> sh = mDocument->CreateShell(cx, vm, newSet);
   NS_ENSURE_TRUE(sh, false);
   newSet.forget();
   // Note that after we create the shell, we must make sure to destroy it
   sh->SetVerifyReflowEnable(false); // turn off verify reflow while we're reflowing the test frame tree
   vm->SetPresShell(sh);
   {
     nsAutoCauseReflowNotifier crNotifier(this);
     sh->Initialize(r.width, r.height);
   }
   mDocument->BindingManager()->ProcessAttachedQueue();
   sh->FlushPendingNotifications(Flush_Layout);
   sh->SetVerifyReflowEnable(true);  // turn on verify reflow again now that we're done reflowing the test frame tree
   // Force the non-primary presshell to unsuppress; it doesn't want to normally
   // because it thinks it's hidden
   ((PresShell*)sh.get())->mPaintingSuppressed = false;
   if (VERIFY_REFLOW_NOISY & gVerifyReflowFlags) {
      printf("Verification Tree built, comparing...\n");
   }
   // Now that the document has been reflowed, use its frame tree to
   // compare against our frame tree.
   nsIFrame* root1 = mFrameConstructor->GetRootFrame();
   nsIFrame* root2 = sh->GetRootFrame();
   bool ok = CompareTrees(mPresContext, root1, cx, root2);
   if (!ok && (VERIFY_REFLOW_NOISY & gVerifyReflowFlags)) {
     printf("Verify reflow failed, primary tree:\n");
     root1->List(stdout, 0);
     printf("Verification tree:\n");
     root2->List(stdout, 0);
   }
 #ifdef DEBUG_Eli
   // Sample code for dumping page to png
   // XXX Needs to be made more flexible
   if (!ok) {
     nsString stra;
     static int num = 0;
     stra.AppendLiteral("C:\\mozilla\\mozilla\\debug\\filea");
     stra.AppendInt(num);
     stra.AppendLiteral(".png");
     DumpToPNG(sh, stra);
     nsString strb;
     strb.AppendLiteral("C:\\mozilla\\mozilla\\debug\\fileb");
     strb.AppendInt(num);
     strb.AppendLiteral(".png");
     DumpToPNG(this, strb);
     ++num;
   }
 #endif
   sh->EndObservingDocument();
   sh->Destroy();
   if (VERIFY_REFLOW_NOISY & gVerifyReflowFlags) {
     printf("Finished Verifying Reflow...\n");
   }
   return ok;
 }
 // Layout debugging hooks
 void
 PresShell::ListStyleContexts(nsIFrame *aRootFrame, FILE *out, int32_t aIndent)
 {
   nsStyleContext *sc = aRootFrame->StyleContext();
   if (sc)
     sc->List(out, aIndent);
 }
 void
 PresShell::ListStyleSheets(FILE *out, int32_t aIndent)
 {
   int32_t sheetCount = mStyleSet->SheetCount(nsStyleSet::eDocSheet);
   for (int32_t i = 0; i < sheetCount; ++i) {
     mStyleSet->StyleSheetAt(nsStyleSet::eDocSheet, i)->List(out, aIndent);
     fputs("\n", out);
   }
 }
 void
 PresShell::VerifyStyleTree()
 {
   VERIFY_STYLE_TREE;
 }
 #endif
 //=============================================================
 //=============================================================
 //-- Debug Reflow Counts
 //=============================================================
 //=============================================================
 #ifdef MOZ_REFLOW_PERF
 //-------------------------------------------------------------
 void
 PresShell::DumpReflows()
 {
   if (mReflowCountMgr) {
     nsAutoCString uriStr;
     if (mDocument) {
       nsIURI *uri = mDocument->GetDocumentURI();
       if (uri) {
         uri->GetPath(uriStr);
       }
     }
     mReflowCountMgr->DisplayTotals(uriStr.get());
     mReflowCountMgr->DisplayHTMLTotals(uriStr.get());
     mReflowCountMgr->DisplayDiffsInTotals("Differences");
   }
 }
 //-------------------------------------------------------------
 void
 PresShell::CountReflows(const char * aName, nsIFrame * aFrame)
 {
   if (mReflowCountMgr) {
     mReflowCountMgr->Add(aName, aFrame);
   }
 }
 //-------------------------------------------------------------
 void
 PresShell::PaintCount(const char * aName,
                       nsRenderingContext* aRenderingContext,
                       nsPresContext* aPresContext,
                       nsIFrame * aFrame,
                       const nsPoint& aOffset,
                       uint32_t aColor)
 {
   if (mReflowCountMgr) {
     mReflowCountMgr->PaintCount(aName, aRenderingContext, aPresContext,
                                 aFrame, aOffset, aColor);
   }
 }
 //-------------------------------------------------------------
 void
 PresShell::SetPaintFrameCount(bool aPaintFrameCounts)
 {
   if (mReflowCountMgr) {
     mReflowCountMgr->SetPaintFrameCounts(aPaintFrameCounts);
   }
 }
 bool
 PresShell::IsPaintingFrameCounts()
 {
   if (mReflowCountMgr)
     return mReflowCountMgr->IsPaintingFrameCounts();
   return false;
 }
 //------------------------------------------------------------------
 //-- Reflow Counter Classes Impls
 //------------------------------------------------------------------
 //------------------------------------------------------------------
 ReflowCounter::ReflowCounter(ReflowCountMgr * aMgr) :
   mMgr(aMgr)
 {
   ClearTotals();
   SetTotalsCache();
 }
 //------------------------------------------------------------------
 ReflowCounter::~ReflowCounter()
 {
 }
 //------------------------------------------------------------------
 void ReflowCounter::ClearTotals()
 {
   mTotal = 0;
 }
 //------------------------------------------------------------------
 void ReflowCounter::SetTotalsCache()
 {
   mCacheTotal = mTotal;
 }
 //------------------------------------------------------------------
 void ReflowCounter::CalcDiffInTotals()
 {
   mCacheTotal = mTotal - mCacheTotal;
 }
 //------------------------------------------------------------------
 void ReflowCounter::DisplayTotals(const char * aStr)
 {
   DisplayTotals(mTotal, aStr?aStr:"Totals");
 }
 //------------------------------------------------------------------
 void ReflowCounter::DisplayDiffTotals(const char * aStr)
 {
   DisplayTotals(mCacheTotal, aStr?aStr:"Diff Totals");
 }
 //------------------------------------------------------------------
 void ReflowCounter::DisplayHTMLTotals(const char * aStr)
 {
   DisplayHTMLTotals(mTotal, aStr?aStr:"Totals");
 }
 //------------------------------------------------------------------
 void ReflowCounter::DisplayTotals(uint32_t aTotal, const char * aTitle)
 {
   // figure total
   if (aTotal == 0) {
     return;
   }
   ReflowCounter * gTots = (ReflowCounter *)mMgr->LookUp(kGrandTotalsStr);
   printf("%25s\t", aTitle);
   printf("%d\t", aTotal);
   if (gTots != this && aTotal > 0) {
     gTots->Add(aTotal);
   }
 }
 //------------------------------------------------------------------
 void ReflowCounter::DisplayHTMLTotals(uint32_t aTotal, const char * aTitle)
 {
   if (aTotal == 0) {
     return;
   }
   ReflowCounter * gTots = (ReflowCounter *)mMgr->LookUp(kGrandTotalsStr);
   FILE * fd = mMgr->GetOutFile();
   if (!fd) {
     return;
   }
   fprintf(fd, "<tr><td><center>%s</center></td>", aTitle);
   fprintf(fd, "<td><center>%d</center></td></tr>\n", aTotal);
   if (gTots != this && aTotal > 0) {
     gTots->Add(aTotal);
   }
 }
 //------------------------------------------------------------------
 //-- ReflowCountMgr
 //------------------------------------------------------------------
 #define KEY_BUF_SIZE_FOR_PTR  24 // adequate char[] buffer to sprintf a pointer
 ReflowCountMgr::ReflowCountMgr()
 {
   mCounts = PL_NewHashTable(10, PL_HashString, PL_CompareStrings,
                                 PL_CompareValues, nullptr, nullptr);
   mIndiFrameCounts = PL_NewHashTable(10, PL_HashString, PL_CompareStrings,
                                      PL_CompareValues, nullptr, nullptr);
   mCycledOnce              = false;
   mDumpFrameCounts         = false;
   mDumpFrameByFrameCounts  = false;
   mPaintFrameByFrameCounts = false;
 }
 //------------------------------------------------------------------
 ReflowCountMgr::~ReflowCountMgr()
 {
   CleanUp();
 }
 //------------------------------------------------------------------
 ReflowCounter * ReflowCountMgr::LookUp(const char * aName)
 {
   if (nullptr != mCounts) {
     ReflowCounter * counter = (ReflowCounter *)PL_HashTableLookup(mCounts, aName);
     return counter;
   }
   return nullptr;
 }
 //------------------------------------------------------------------
 void ReflowCountMgr::Add(const char * aName, nsIFrame * aFrame)
 {
   NS_ASSERTION(aName != nullptr, "Name shouldn't be null!");
   if (mDumpFrameCounts && nullptr != mCounts) {
     ReflowCounter * counter = (ReflowCounter *)PL_HashTableLookup(mCounts, aName);
     if (counter == nullptr) {
       counter = new ReflowCounter(this);
       char * name = NS_strdup(aName);
       NS_ASSERTION(name != nullptr, "null ptr");
       PL_HashTableAdd(mCounts, name, counter);
     }
     counter->Add();
   }
   if ((mDumpFrameByFrameCounts || mPaintFrameByFrameCounts) &&
       nullptr != mIndiFrameCounts &&
       aFrame != nullptr) {
     char key[KEY_BUF_SIZE_FOR_PTR];
     sprintf(key, "%p", (void*)aFrame);
     IndiReflowCounter * counter = (IndiReflowCounter *)PL_HashTableLookup(mIndiFrameCounts, key);
     if (counter == nullptr) {
       counter = new IndiReflowCounter(this);
       counter->mFrame = aFrame;
       counter->mName.AssignASCII(aName);
       PL_HashTableAdd(mIndiFrameCounts, NS_strdup(key), counter);
     }
     // this eliminates extra counts from super classes
     if (counter != nullptr && counter->mName.EqualsASCII(aName)) {
       counter->mCount++;
       counter->mCounter.Add(1);
     }
   }
 }
 //------------------------------------------------------------------
 void ReflowCountMgr::PaintCount(const char*     aName,
                                 nsRenderingContext* aRenderingContext,
                                 nsPresContext*  aPresContext,
                                 nsIFrame*       aFrame,
                                 const nsPoint&  aOffset,
                                 uint32_t        aColor)
 {
   if (mPaintFrameByFrameCounts &&
       nullptr != mIndiFrameCounts &&
       aFrame != nullptr) {
     char key[KEY_BUF_SIZE_FOR_PTR];
     sprintf(key, "%p", (void*)aFrame);
     IndiReflowCounter * counter =
       (IndiReflowCounter *)PL_HashTableLookup(mIndiFrameCounts, key);
     if (counter != nullptr && counter->mName.EqualsASCII(aName)) {
       aRenderingContext->PushState();
       aRenderingContext->Translate(aOffset);
       nsFont font("Times", NS_FONT_STYLE_NORMAL, NS_FONT_VARIANT_NORMAL,
                   NS_FONT_WEIGHT_NORMAL, NS_FONT_STRETCH_NORMAL, 0,
                   nsPresContext::CSSPixelsToAppUnits(11));
       nsRefPtr<nsFontMetrics> fm;
       aPresContext->DeviceContext()->GetMetricsFor(font,
         // We have one frame, therefore we must have a root...
         aPresContext->GetPresShell()->GetRootFrame()->
           StyleFont()->mLanguage,
         aPresContext->GetUserFontSet(),
         aPresContext->GetTextPerfMetrics(),
         *getter_AddRefs(fm));
       aRenderingContext->SetFont(fm);
       char buf[16];
       sprintf(buf, "%d", counter->mCount);
       nscoord x = 0, y = fm->MaxAscent();
       nscoord width, height = fm->MaxHeight();
       aRenderingContext->SetTextRunRTL(false);
       width = aRenderingContext->GetWidth(buf);
       uint32_t color;
       uint32_t color2;
       if (aColor != 0) {
         color  = aColor;
         color2 = NS_RGB(0,0,0);
       } else {
         uint8_t rc = 0, gc = 0, bc = 0;
         if (counter->mCount < 5) {
           rc = 255;
           gc = 255;
         } else if ( counter->mCount < 11) {
           gc = 255;
         } else {
           rc = 255;
         }
         color  = NS_RGB(rc,gc,bc);
         color2 = NS_RGB(rc/2,gc/2,bc/2);
       }
       nsRect rect(0,0, width+15, height+15);
       aRenderingContext->SetColor(NS_RGB(0,0,0));
       aRenderingContext->FillRect(rect);
       aRenderingContext->SetColor(color2);
       aRenderingContext->DrawString(buf, strlen(buf), x+15,y+15);
       aRenderingContext->SetColor(color);
       aRenderingContext->DrawString(buf, strlen(buf), x,y);
       aRenderingContext->PopState();
     }
   }
 }
 //------------------------------------------------------------------
 int ReflowCountMgr::RemoveItems(PLHashEntry *he, int i, void *arg)
 {
   char *str = (char *)he->key;
   ReflowCounter * counter = (ReflowCounter *)he->value;
   delete counter;
   NS_Free(str);
   return HT_ENUMERATE_REMOVE;
 }
 //------------------------------------------------------------------
 int ReflowCountMgr::RemoveIndiItems(PLHashEntry *he, int i, void *arg)
 {
   char *str = (char *)he->key;
   IndiReflowCounter * counter = (IndiReflowCounter *)he->value;
   delete counter;
   NS_Free(str);
   return HT_ENUMERATE_REMOVE;
 }
 //------------------------------------------------------------------
 void ReflowCountMgr::CleanUp()
 {
   if (nullptr != mCounts) {
     PL_HashTableEnumerateEntries(mCounts, RemoveItems, nullptr);
     PL_HashTableDestroy(mCounts);
     mCounts = nullptr;
   }
   if (nullptr != mIndiFrameCounts) {
     PL_HashTableEnumerateEntries(mIndiFrameCounts, RemoveIndiItems, nullptr);
     PL_HashTableDestroy(mIndiFrameCounts);
     mIndiFrameCounts = nullptr;
   }
 }
 //------------------------------------------------------------------
 int ReflowCountMgr::DoSingleTotal(PLHashEntry *he, int i, void *arg)
 {
   char *str = (char *)he->key;
   ReflowCounter * counter = (ReflowCounter *)he->value;
   counter->DisplayTotals(str);
   return HT_ENUMERATE_NEXT;
 }
 //------------------------------------------------------------------
 void ReflowCountMgr::DoGrandTotals()
 {
   if (nullptr != mCounts) {
     ReflowCounter * gTots = (ReflowCounter *)PL_HashTableLookup(mCounts, kGrandTotalsStr);
     if (gTots == nullptr) {
       gTots = new ReflowCounter(this);
       PL_HashTableAdd(mCounts, NS_strdup(kGrandTotalsStr), gTots);
     } else {
       gTots->ClearTotals();
     }
     printf("\t\t\t\tTotal\n");
     for (uint32_t i=0;i<78;i++) {
       printf("-");
     }
     printf("\n");
     PL_HashTableEnumerateEntries(mCounts, DoSingleTotal, this);
   }
 }
 static void RecurseIndiTotals(nsPresContext* aPresContext,
                               PLHashTable *   aHT,
                               nsIFrame *      aParentFrame,
                               int32_t         aLevel)
 {
   if (aParentFrame == nullptr) {
     return;
   }
   char key[KEY_BUF_SIZE_FOR_PTR];
   sprintf(key, "%p", (void*)aParentFrame);
   IndiReflowCounter * counter = (IndiReflowCounter *)PL_HashTableLookup(aHT, key);
   if (counter) {
     counter->mHasBeenOutput = true;
     char * name = ToNewCString(counter->mName);
     for (int32_t i=0;i<aLevel;i++) printf(" ");
     printf("%s - %p   [%d][", name, (void*)aParentFrame, counter->mCount);
     printf("%d", counter->mCounter.GetTotal());
     printf("]\n");
     nsMemory::Free(name);
   }
   nsIFrame* child = aParentFrame->GetFirstPrincipalChild();
   while (child) {
     RecurseIndiTotals(aPresContext, aHT, child, aLevel+1);
     child = child->GetNextSibling();
   }
 }
 //------------------------------------------------------------------
 int ReflowCountMgr::DoSingleIndi(PLHashEntry *he, int i, void *arg)
 {
   IndiReflowCounter * counter = (IndiReflowCounter *)he->value;
   if (counter && !counter->mHasBeenOutput) {
     char * name = ToNewCString(counter->mName);
     printf("%s - %p   [%d][", name, (void*)counter->mFrame, counter->mCount);
     printf("%d", counter->mCounter.GetTotal());
     printf("]\n");
     nsMemory::Free(name);
   }
   return HT_ENUMERATE_NEXT;
 }
 //------------------------------------------------------------------
 void ReflowCountMgr::DoIndiTotalsTree()
 {
   if (nullptr != mCounts) {
     printf("\n------------------------------------------------\n");
     printf("-- Individual Frame Counts\n");
     printf("------------------------------------------------\n");
     if (mPresShell) {
       nsIFrame * rootFrame = mPresShell->FrameManager()->GetRootFrame();
       RecurseIndiTotals(mPresContext, mIndiFrameCounts, rootFrame, 0);
       printf("------------------------------------------------\n");
       printf("-- Individual Counts of Frames not in Root Tree\n");
       printf("------------------------------------------------\n");
       PL_HashTableEnumerateEntries(mIndiFrameCounts, DoSingleIndi, this);
     }
   }
 }
 //------------------------------------------------------------------
 int ReflowCountMgr::DoSingleHTMLTotal(PLHashEntry *he, int i, void *arg)
 {
   char *str = (char *)he->key;
   ReflowCounter * counter = (ReflowCounter *)he->value;
   counter->DisplayHTMLTotals(str);
   return HT_ENUMERATE_NEXT;
 }
 //------------------------------------------------------------------
 void ReflowCountMgr::DoGrandHTMLTotals()
 {
   if (nullptr != mCounts) {
     ReflowCounter * gTots = (ReflowCounter *)PL_HashTableLookup(mCounts, kGrandTotalsStr);
     if (gTots == nullptr) {
       gTots = new ReflowCounter(this);
       PL_HashTableAdd(mCounts, NS_strdup(kGrandTotalsStr), gTots);
     } else {
       gTots->ClearTotals();
     }
     static const char * title[] = {"Class", "Reflows"};
     fprintf(mFD, "<tr>");
     for (uint32_t i=0; i < ArrayLength(title); i++) {
       fprintf(mFD, "<td><center><b>%s<b></center></td>", title[i]);
     }
     fprintf(mFD, "</tr>\n");
     PL_HashTableEnumerateEntries(mCounts, DoSingleHTMLTotal, this);
   }
 }
 //------------------------------------
 void ReflowCountMgr::DisplayTotals(const char * aStr)
 {
 #ifdef DEBUG_rods
   printf("%s\n", aStr?aStr:"No name");
 #endif
   if (mDumpFrameCounts) {
     DoGrandTotals();
   }
   if (mDumpFrameByFrameCounts) {
     DoIndiTotalsTree();
   }
 }
 //------------------------------------
 void ReflowCountMgr::DisplayHTMLTotals(const char * aStr)
 {
 #ifdef WIN32x // XXX NOT XP!
   char name[1024];
   char * sptr = strrchr(aStr, '/');
   if (sptr) {
     sptr++;
     strcpy(name, sptr);
     char * eptr = strrchr(name, '.');
     if (eptr) {
       *eptr = 0;
     }
     strcat(name, "_stats.html");
   }
   mFD = fopen(name, "w");
   if (mFD) {
     fprintf(mFD, "<html><head><title>Reflow Stats</title></head><body>\n");
     const char * title = aStr?aStr:"No name";
     fprintf(mFD, "<center><b>%s</b><br><table border=1 style=\"background-color:#e0e0e0\">", title);
     DoGrandHTMLTotals();
     fprintf(mFD, "</center></table>\n");
     fprintf(mFD, "</body></html>\n");
     fclose(mFD);
     mFD = nullptr;
   }
 #endif // not XP!
 }
 //------------------------------------------------------------------
 int ReflowCountMgr::DoClearTotals(PLHashEntry *he, int i, void *arg)
 {
   ReflowCounter * counter = (ReflowCounter *)he->value;
   counter->ClearTotals();
   return HT_ENUMERATE_NEXT;
 }
 //------------------------------------------------------------------
 void ReflowCountMgr::ClearTotals()
 {
   PL_HashTableEnumerateEntries(mCounts, DoClearTotals, this);
 }
 //------------------------------------------------------------------
 void ReflowCountMgr::ClearGrandTotals()
 {
   if (nullptr != mCounts) {
     ReflowCounter * gTots = (ReflowCounter *)PL_HashTableLookup(mCounts, kGrandTotalsStr);
     if (gTots == nullptr) {
       gTots = new ReflowCounter(this);
       PL_HashTableAdd(mCounts, NS_strdup(kGrandTotalsStr), gTots);
     } else {
       gTots->ClearTotals();
       gTots->SetTotalsCache();
     }
   }
 }
 //------------------------------------------------------------------
 int ReflowCountMgr::DoDisplayDiffTotals(PLHashEntry *he, int i, void *arg)
 {
   bool cycledOnce = (arg != 0);
   char *str = (char *)he->key;
   ReflowCounter * counter = (ReflowCounter *)he->value;
   if (cycledOnce) {
     counter->CalcDiffInTotals();
     counter->DisplayDiffTotals(str);
   }
   counter->SetTotalsCache();
   return HT_ENUMERATE_NEXT;
 }
 //------------------------------------------------------------------
 void ReflowCountMgr::DisplayDiffsInTotals(const char * aStr)
 {
   if (mCycledOnce) {
     printf("Differences\n");
     for (int32_t i=0;i<78;i++) {
       printf("-");
     }
     printf("\n");
     ClearGrandTotals();
   }
   PL_HashTableEnumerateEntries(mCounts, DoDisplayDiffTotals, (void *)mCycledOnce);
   mCycledOnce = true;
 }
 #endif // MOZ_REFLOW_PERF
 // make a color string like #RRGGBB
 void ColorToString(nscolor aColor, nsAutoString &aString)
 {
   char buf[8];
   PR_snprintf(buf, sizeof(buf), "#%02x%02x%02x",
               NS_GET_R(aColor), NS_GET_G(aColor), NS_GET_B(aColor));
   CopyASCIItoUTF16(buf, aString);
 }
 nsIFrame* nsIPresShell::GetAbsoluteContainingBlock(nsIFrame *aFrame)
 {
   return FrameConstructor()->GetAbsoluteContainingBlock(aFrame,
       nsCSSFrameConstructor::ABS_POS);
 }
 #ifdef ACCESSIBILITY
 bool
 nsIPresShell::IsAccessibilityActive()
 {
   return GetAccService() != nullptr;
 }
 nsAccessibilityService*
 nsIPresShell::AccService()
 {
   return GetAccService();
 }
 #endif
 void nsIPresShell::InitializeStatics()
 {
   NS_ASSERTION(!gCaptureTouchList, "InitializeStatics called multiple times!");
   gCaptureTouchList = new nsRefPtrHashtable<nsUint32HashKey, dom::Touch>;
   gPointerCaptureList = new nsRefPtrHashtable<nsUint32HashKey, nsIContent>;
   gActivePointersIds = new nsClassHashtable<nsUint32HashKey, PointerInfo>;
 }
 void nsIPresShell::ReleaseStatics()
 {
   NS_ASSERTION(gCaptureTouchList, "ReleaseStatics called without Initialize!");
   delete gCaptureTouchList;
   gCaptureTouchList = nullptr;
   delete gPointerCaptureList;
   gPointerCaptureList = nullptr;
   delete gActivePointersIds;
   gActivePointersIds = nullptr;
 }
 // Asks our docshell whether we're active.
 void PresShell::QueryIsActive()
 {
   nsCOMPtr<nsISupports> container = mPresContext->GetContainerWeak();
   if (mDocument) {
     nsIDocument* displayDoc = mDocument->GetDisplayDocument();
     if (displayDoc) {
       // Ok, we're an external resource document -- we need to use our display
       // document's docshell to determine "IsActive" status, since we lack
       // a container.
       NS_ABORT_IF_FALSE(!container,
                         "external resource doc shouldn't have "
                         "its own container");
       nsIPresShell* displayPresShell = displayDoc->GetShell();
       if (displayPresShell) {
         container = displayPresShell->GetPresContext()->GetContainerWeak();
       }
     }
   }
   nsCOMPtr<nsIDocShell> docshell(do_QueryInterface(container));
   if (docshell) {
     bool isActive;
     nsresult rv = docshell->GetIsActive(&isActive);
     if (NS_SUCCEEDED(rv))
       SetIsActive(isActive);
   }
 }
 // Helper for propagating mIsActive changes to external resources
 static bool
 SetExternalResourceIsActive(nsIDocument* aDocument, void* aClosure)
 {
   nsIPresShell* shell = aDocument->GetShell();
   if (shell) {
     shell->SetIsActive(*static_cast<bool*>(aClosure));
   }
   return true;
 }
 static void
 SetPluginIsActive(nsIContent* aContent, void* aClosure)
 {
   nsIFrame *frame = aContent->GetPrimaryFrame();
   nsIObjectFrame *objectFrame = do_QueryFrame(frame);
   if (objectFrame) {
     objectFrame->SetIsDocumentActive(*static_cast<bool*>(aClosure));
   }
 }
 nsresult
 PresShell::SetIsActive(bool aIsActive)
 {
   NS_PRECONDITION(mDocument, "should only be called with a document");
   mIsActive = aIsActive;
   nsPresContext* presContext = GetPresContext();
   if (presContext &&
       presContext->RefreshDriver()->PresContext() == presContext) {
     presContext->RefreshDriver()->SetThrottled(!mIsActive);
   }
   // Propagate state-change to my resource documents' PresShells
   mDocument->EnumerateExternalResources(SetExternalResourceIsActive,
                                         &aIsActive);
   mDocument->EnumerateFreezableElements(SetPluginIsActive,
                                         &aIsActive);
   nsresult rv = UpdateImageLockingState();
 #ifdef ACCESSIBILITY
   if (aIsActive) {
     nsAccessibilityService* accService = AccService();
     if (accService) {
       accService->PresShellActivated(this);
     }
   }
 #endif
   // We have this odd special case here because remote content behaves
   // differently from same-process content when "hidden".  In
   // desktop-type "browser UIs", hidden "tabs" have documents that are
   // part of the chrome tree.  When the tabs are hidden, their content
   // is no longer part of the visible document tree, and the layers
   // for the content are naturally released.
   //
   // Remote content is its own top-level tree in its subprocess.  When
   // it's "hidden", there's no transaction in which the document
   // thinks it's not visible, so layers can be retained forever.  This
   // is problematic when those layers uselessly hold on to precious
   // resources like directly texturable memory.
   //
   // PresShell::SetIsActive() is the first C++ entry point at which we
   // (i) know that our parent process wants our content to be hidden;
   // and (ii) has easy access to the TabChild.  So we use this
   // notification to signal the TabChild to drop its layer tree and
   // stop trying to repaint.
   if (TabChild* tab = TabChild::GetFrom(this)) {
     if (aIsActive) {
       tab->MakeVisible();
       if (!mIsZombie) {
         if (nsIFrame* root = mFrameConstructor->GetRootFrame()) {
           FrameLayerBuilder::InvalidateAllLayersForFrame(
             nsLayoutUtils::GetDisplayRootFrame(root));
           root->SchedulePaint();
         }
       }
     } else {
       tab->MakeHidden();
     }
   }
   return rv;
 }
 /*
  * Determines the current image locking state. Called when one of the
  * dependent factors changes.
  */
 nsresult
 PresShell::UpdateImageLockingState()
 {
   // We're locked if we're both thawed and active.
   return mDocument->SetImageLockingState(!mFrozen && mIsActive);
 }
 PresShell*
 PresShell::GetRootPresShell()
 {
   if (mPresContext) {
     nsPresContext* rootPresContext = mPresContext->GetRootPresContext();
     if (rootPresContext) {
       return static_cast<PresShell*>(rootPresContext->PresShell());
     }
   }
   return nullptr;
 }
 void
 PresShell::AddSizeOfIncludingThis(MallocSizeOf aMallocSizeOf,
                                   nsArenaMemoryStats *aArenaObjectsSize,
                                   size_t *aPresShellSize,
                                   size_t *aStyleSetsSize,
                                   size_t *aTextRunsSize,
                                   size_t *aPresContextSize)
 {
   mFrameArena.AddSizeOfExcludingThis(aMallocSizeOf, aArenaObjectsSize);
   *aPresShellSize += aMallocSizeOf(this);
   *aPresShellSize += aArenaObjectsSize->mOther;
   *aStyleSetsSize += StyleSet()->SizeOfIncludingThis(aMallocSizeOf);
   *aTextRunsSize += SizeOfTextRuns(aMallocSizeOf);
   *aPresContextSize += mPresContext->SizeOfIncludingThis(aMallocSizeOf);
 }
 size_t
 PresShell::SizeOfTextRuns(MallocSizeOf aMallocSizeOf) const
 {
   nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
   if (!rootFrame) {
     return 0;
   }
   // clear the TEXT_RUN_MEMORY_ACCOUNTED flags
   nsLayoutUtils::SizeOfTextRunsForFrames(rootFrame, nullptr,
                                          /* clear = */true);
   // collect the total memory in use for textruns
   return nsLayoutUtils::SizeOfTextRunsForFrames(rootFrame, aMallocSizeOf,
                                                 /* clear = */false);
 }
 void
 nsIPresShell::MarkFixedFramesForReflow(IntrinsicDirty aIntrinsicDirty)
 {
   nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
   if (rootFrame) {
     const nsFrameList& childList = rootFrame->GetChildList(nsIFrame::kFixedList);
     for (nsFrameList::Enumerator e(childList); !e.AtEnd(); e.Next()) {
       FrameNeedsReflow(e.get(), aIntrinsicDirty, NS_FRAME_IS_DIRTY);
     }
   }
 }
 void
 nsIPresShell::SetScrollPositionClampingScrollPortSize(nscoord aWidth, nscoord aHeight)
 {
   if (!mScrollPositionClampingScrollPortSizeSet ||
       mScrollPositionClampingScrollPortSize.width != aWidth ||
       mScrollPositionClampingScrollPortSize.height != aHeight) {
     mScrollPositionClampingScrollPortSizeSet = true;
     mScrollPositionClampingScrollPortSize.width = aWidth;
     mScrollPositionClampingScrollPortSize.height = aHeight;
     MarkFixedFramesForReflow(eResize);
   }
 }
 void
 nsIPresShell::SetContentDocumentFixedPositionMargins(const nsMargin& aMargins)
 {
   if (mContentDocumentFixedPositionMargins == aMargins) {
     return;
   }
   mContentDocumentFixedPositionMargins = aMargins;
   MarkFixedFramesForReflow(eResize);
 }
 void
 PresShell::SetupFontInflation()
 {
   mFontSizeInflationEmPerLine = nsLayoutUtils::FontSizeInflationEmPerLine();
   mFontSizeInflationMinTwips = nsLayoutUtils::FontSizeInflationMinTwips();
   mFontSizeInflationLineThreshold = nsLayoutUtils::FontSizeInflationLineThreshold();
   mFontSizeInflationForceEnabled = nsLayoutUtils::FontSizeInflationForceEnabled();
   mFontSizeInflationDisabledInMasterProcess = nsLayoutUtils::FontSizeInflationDisabledInMasterProcess();
   NotifyFontSizeInflationEnabledIsDirty();
 }
 void
 nsIPresShell::RecomputeFontSizeInflationEnabled()
 {
   mFontSizeInflationEnabledIsDirty = false;
   MOZ_ASSERT(mPresContext, "our pres context should not be null");
   if ((FontSizeInflationEmPerLine() == 0 &&
       FontSizeInflationMinTwips() == 0) || mPresContext->IsChrome()) {
     mFontSizeInflationEnabled = false;
     return;
   }
   // Force-enabling font inflation always trumps the heuristics here.
   if (!FontSizeInflationForceEnabled()) {
     if (TabChild* tab = TabChild::GetFrom(this)) {
       // We're in a child process.  Cancel inflation if we're not
       // async-pan zoomed.
       if (!tab->IsAsyncPanZoomEnabled()) {
         mFontSizeInflationEnabled = false;
         return;
       }
     } else if (XRE_GetProcessType() == GeckoProcessType_Default) {
       // We're in the master process.  Cancel inflation if it's been
       // explicitly disabled.
       if (FontSizeInflationDisabledInMasterProcess()) {
         mFontSizeInflationEnabled = false;
         return;
       }
     }
   }
   // XXXjwir3:
   // See bug 706918, comment 23 for more information on this particular section
   // of the code. We're using "screen size" in place of the size of the content
   // area, because on mobile, these are close or equal. This will work for our
   // purposes (bug 706198), but it will need to be changed in the future to be
   // more correct when we bring the rest of the viewport code into platform.
   // We actually want the size of the content area, in the event that we don't
   // have any metadata about the width and/or height. On mobile, the screen size
   // and the size of the content area are very close, or the same value.
   // In XUL fennec, the content area is the size of the <browser> widget, but
   // in native fennec, the content area is the size of the Gecko LayerView
   // object.
   // TODO:
   // Once bug 716575 has been resolved, this code should be changed so that it
   // does the right thing on all platforms.
   nsresult rv;
   nsCOMPtr<nsIScreenManager> screenMgr =
     do_GetService("@mozilla.org/gfx/screenmanager;1", &rv);
   if (!NS_SUCCEEDED(rv)) {
     mFontSizeInflationEnabled = false;
     return;
   }
   nsCOMPtr<nsIScreen> screen;
   screenMgr->GetPrimaryScreen(getter_AddRefs(screen));
   if (screen) {
     int32_t screenLeft, screenTop, screenWidth, screenHeight;
     screen->GetRect(&screenLeft, &screenTop, &screenWidth, &screenHeight);
     nsViewportInfo vInf =
       nsContentUtils::GetViewportInfo(GetDocument(), ScreenIntSize(screenWidth, screenHeight));
     if (vInf.GetDefaultZoom() >= CSSToScreenScale(1.0f) || vInf.IsAutoSizeEnabled()) {
       mFontSizeInflationEnabled = false;
       return;
     }
   }
   mFontSizeInflationEnabled = true;
 }
 bool
 nsIPresShell::FontSizeInflationEnabled()
 {
   if (mFontSizeInflationEnabledIsDirty) {
     RecomputeFontSizeInflationEnabled();
   }
   return mFontSizeInflationEnabled;
 }
 void
 nsIPresShell::SetMaxLineBoxWidth(nscoord aMaxLineBoxWidth)
 {
   NS_ASSERTION(aMaxLineBoxWidth >= 0, "attempting to set max line box width to a negative value");
   if (mMaxLineBoxWidth != aMaxLineBoxWidth) {
     mMaxLineBoxWidth = aMaxLineBoxWidth;
     mReflowOnZoomPending = true;
     FrameNeedsReflow(GetRootFrame(), eResize, NS_FRAME_HAS_DIRTY_CHILDREN);
   }
 }
 void
 PresShell::PausePainting()
 {
   if (GetPresContext()->RefreshDriver()->PresContext() != GetPresContext())
     return;
   mPaintingIsFrozen = true;
   GetPresContext()->RefreshDriver()->Freeze();
 }
 void
 PresShell::ResumePainting()
 {
   if (GetPresContext()->RefreshDriver()->PresContext() != GetPresContext())
     return;
   mPaintingIsFrozen = false;
   GetPresContext()->RefreshDriver()->Thaw();
 }

The Tor Browser / annotate

layout/base/nsPresShell.cpp@6474c204b198 (annotated)

layout/base/nsPresShell.cpp