The Tor Browser: layout/mathml/nsMathMLmactionFrame.cpp@97036ab72558 (annotated)

layout/mathml/nsMathMLmactionFrame.cpp@97036ab72558 (annotated)

layout/mathml/nsMathMLmactionFrame.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* 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/. */
 #include "nsMathMLmactionFrame.h"
 #include "nsCOMPtr.h"
 #include "nsPresContext.h"
 #include "nsNameSpaceManager.h"
 #include "prprf.h"         // For PR_snprintf()
 #include "nsIDocShell.h"
 #include "nsIDocShellTreeOwner.h"
 #include "nsIWebBrowserChrome.h"
 #include "nsIInterfaceRequestorUtils.h"
 #include "nsTextFragment.h"
 #include "nsIDOMEvent.h"
 #include "mozilla/gfx/2D.h"
 //
 // <maction> -- bind actions to a subexpression - implementation
 //
 enum nsMactionActionTypes {
   NS_MATHML_ACTION_TYPE_CLASS_ERROR            = 0x10,
   NS_MATHML_ACTION_TYPE_CLASS_USE_SELECTION    = 0x20,
   NS_MATHML_ACTION_TYPE_CLASS_IGNORE_SELECTION = 0x40,
   NS_MATHML_ACTION_TYPE_CLASS_BITMASK          = 0xF0,
   NS_MATHML_ACTION_TYPE_NONE       = NS_MATHML_ACTION_TYPE_CLASS_ERROR|0x01,
   NS_MATHML_ACTION_TYPE_TOGGLE     = NS_MATHML_ACTION_TYPE_CLASS_USE_SELECTION|0x01,
   NS_MATHML_ACTION_TYPE_UNKNOWN    = NS_MATHML_ACTION_TYPE_CLASS_USE_SELECTION|0x02,
   NS_MATHML_ACTION_TYPE_STATUSLINE = NS_MATHML_ACTION_TYPE_CLASS_IGNORE_SELECTION|0x01,
   NS_MATHML_ACTION_TYPE_TOOLTIP    = NS_MATHML_ACTION_TYPE_CLASS_IGNORE_SELECTION|0x02
 };
 // helper function to parse actiontype attribute
 static int32_t
 GetActionType(nsIContent* aContent)
 {
   nsAutoString value;
   if (aContent) {
     if (!aContent->GetAttr(kNameSpaceID_None, nsGkAtoms::actiontype_, value))
       return NS_MATHML_ACTION_TYPE_NONE;
   }
   if (value.EqualsLiteral("toggle"))
     return NS_MATHML_ACTION_TYPE_TOGGLE;
   if (value.EqualsLiteral("statusline"))
     return NS_MATHML_ACTION_TYPE_STATUSLINE;
   if (value.EqualsLiteral("tooltip"))
     return NS_MATHML_ACTION_TYPE_TOOLTIP;
   return NS_MATHML_ACTION_TYPE_UNKNOWN;
 }
 nsIFrame*
 NS_NewMathMLmactionFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 {
   return new (aPresShell) nsMathMLmactionFrame(aContext);
 }
 NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmactionFrame)
 nsMathMLmactionFrame::~nsMathMLmactionFrame()
 {
   // unregister us as a mouse event listener ...
   //  printf("maction:%p unregistering as mouse event listener ...\n", this);
   if (mListener) {
     mContent->RemoveSystemEventListener(NS_LITERAL_STRING("click"), mListener,
                                         false);
     mContent->RemoveSystemEventListener(NS_LITERAL_STRING("mouseover"), mListener,
                                         false);
     mContent->RemoveSystemEventListener(NS_LITERAL_STRING("mouseout"), mListener,
                                         false);
   }
 }
 void
 nsMathMLmactionFrame::Init(nsIContent*      aContent,
                            nsIFrame*        aParent,
                            nsIFrame*        aPrevInFlow)
 {
   // Init our local attributes
   mChildCount = -1; // these will be updated in GetSelectedFrame()
   mActionType = GetActionType(aContent);
   // Let the base class do the rest
   return nsMathMLSelectedFrame::Init(aContent, aParent, aPrevInFlow);
 }
 nsresult
 nsMathMLmactionFrame::ChildListChanged(int32_t aModType)
 {
   // update cached values
   mChildCount = -1;
   mSelectedFrame = nullptr;
   return nsMathMLSelectedFrame::ChildListChanged(aModType);
 }
 // return the frame whose number is given by the attribute selection="number"
 nsIFrame*
 nsMathMLmactionFrame::GetSelectedFrame()
 {
   nsAutoString value;
   int32_t selection;
   if ((mActionType & NS_MATHML_ACTION_TYPE_CLASS_BITMASK) ==
        NS_MATHML_ACTION_TYPE_CLASS_ERROR) {
     mSelection = -1;
     mInvalidMarkup = true;
     mSelectedFrame = nullptr;
     return mSelectedFrame;
   }
   // Selection is not applied to tooltip and statusline.
   // Thereby return the first child.
   if ((mActionType & NS_MATHML_ACTION_TYPE_CLASS_BITMASK) ==
        NS_MATHML_ACTION_TYPE_CLASS_IGNORE_SELECTION) {
     // We don't touch mChildCount here. It's incorrect to assign it 1,
     // and it's inefficient to count the children. It's fine to leave
     // it be equal -1 because it's not used with other actiontypes.
     mSelection = 1;
     mInvalidMarkup = false;
     mSelectedFrame = mFrames.FirstChild();
     return mSelectedFrame;
   }
   mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::selection_, value);
   if (!value.IsEmpty()) {
     nsresult errorCode;
     selection = value.ToInteger(&errorCode);
     if (NS_FAILED(errorCode))
       selection = 1;
   }
   else selection = 1; // default is first frame
   if (-1 != mChildCount) { // we have been in this function before...
     // cater for invalid user-supplied selection
     if (selection > mChildCount || selection < 1)
       selection = -1;
     // quick return if it is identical with our cache
     if (selection == mSelection)
       return mSelectedFrame;
   }
   // get the selected child and cache new values...
   int32_t count = 0;
   nsIFrame* childFrame = mFrames.FirstChild();
   while (childFrame) {
     if (!mSelectedFrame)
       mSelectedFrame = childFrame; // default is first child
     if (++count == selection)
       mSelectedFrame = childFrame;
     childFrame = childFrame->GetNextSibling();
   }
   // cater for invalid user-supplied selection
   if (selection > count || selection < 1)
     selection = -1;
   mChildCount = count;
   mSelection = selection;
   mInvalidMarkup = (mSelection == -1);
   TransmitAutomaticData();
   return mSelectedFrame;
 }
 nsresult
 nsMathMLmactionFrame::SetInitialChildList(ChildListID     aListID,
                                           nsFrameList&    aChildList)
 {
   nsresult rv = nsMathMLSelectedFrame::SetInitialChildList(aListID, aChildList);
   if (!mSelectedFrame) {
     mActionType = NS_MATHML_ACTION_TYPE_NONE;
   }
   else {
     // create mouse event listener and register it
     mListener = new nsMathMLmactionFrame::MouseListener(this);
     // printf("maction:%p registering as mouse event listener ...\n", this);
     mContent->AddSystemEventListener(NS_LITERAL_STRING("click"), mListener,
                                      false, false);
     mContent->AddSystemEventListener(NS_LITERAL_STRING("mouseover"), mListener,
                                      false, false);
     mContent->AddSystemEventListener(NS_LITERAL_STRING("mouseout"), mListener,
                                      false, false);
   }
   return rv;
 }
 nsresult
 nsMathMLmactionFrame::AttributeChanged(int32_t  aNameSpaceID,
                                        nsIAtom* aAttribute,
                                        int32_t  aModType)
 {
   bool needsReflow = false;
   if (aAttribute == nsGkAtoms::actiontype_) {
     // updating mActionType ...
     int32_t oldActionType = mActionType;
     mActionType = GetActionType(mContent);
     // Initiate a reflow when actiontype classes are different.
     if ((oldActionType & NS_MATHML_ACTION_TYPE_CLASS_BITMASK) !=
           (mActionType & NS_MATHML_ACTION_TYPE_CLASS_BITMASK)) {
       needsReflow = true;
     }
   } else if (aAttribute == nsGkAtoms::selection_) {
     if ((mActionType & NS_MATHML_ACTION_TYPE_CLASS_BITMASK) ==
          NS_MATHML_ACTION_TYPE_CLASS_USE_SELECTION) {
       needsReflow = true;
     }
   } else {
     // let the base class handle other attribute changes
     return
       nsMathMLContainerFrame::AttributeChanged(aNameSpaceID,
                                                aAttribute, aModType);
   }
   if (needsReflow) {
     PresContext()->PresShell()->
       FrameNeedsReflow(this, nsIPresShell::eTreeChange, NS_FRAME_IS_DIRTY);
   }
   return NS_OK;
 }
 // ################################################################
 // Event handlers
 // ################################################################
 NS_IMPL_ISUPPORTS(nsMathMLmactionFrame::MouseListener,
                   nsIDOMEventListener)
 // helper to show a msg on the status bar
 // curled from nsObjectFrame.cpp ...
 void
 ShowStatus(nsPresContext* aPresContext, nsString& aStatusMsg)
 {
   nsCOMPtr<nsIDocShellTreeItem> docShellItem(aPresContext->GetDocShell());
   if (docShellItem) {
     nsCOMPtr<nsIDocShellTreeOwner> treeOwner;
     docShellItem->GetTreeOwner(getter_AddRefs(treeOwner));
     if (treeOwner) {
       nsCOMPtr<nsIWebBrowserChrome> browserChrome(do_GetInterface(treeOwner));
       if (browserChrome) {
         browserChrome->SetStatus(nsIWebBrowserChrome::STATUS_LINK, aStatusMsg.get());
       }
     }
   }
 }
 NS_IMETHODIMP
 nsMathMLmactionFrame::MouseListener::HandleEvent(nsIDOMEvent* aEvent)
 {
   nsAutoString eventType;
   aEvent->GetType(eventType);
   if (eventType.EqualsLiteral("mouseover")) {
     mOwner->MouseOver();
   }
   else if (eventType.EqualsLiteral("click")) {
     mOwner->MouseClick();
   }
   else if (eventType.EqualsLiteral("mouseout")) {
     mOwner->MouseOut();
   }
   else {
     NS_ABORT();
   }
   return NS_OK;
 }
 void
 nsMathMLmactionFrame::MouseOver()
 {
   // see if we should display a status message
   if (NS_MATHML_ACTION_TYPE_STATUSLINE == mActionType) {
     // retrieve content from a second child if it exists
     nsIFrame* childFrame = mFrames.FrameAt(1);
     if (!childFrame) return;
     nsIContent* content = childFrame->GetContent();
     if (!content) return;
     // check whether the content is mtext or not
     if (content->GetNameSpaceID() == kNameSpaceID_MathML &&
         content->Tag() == nsGkAtoms::mtext_) {
       // get the text to be displayed
       content = content->GetFirstChild();
       if (!content) return;
       const nsTextFragment* textFrg = content->GetText();
       if (!textFrg) return;
       nsAutoString text;
       textFrg->AppendTo(text);
       // collapse whitespaces as listed in REC, section 3.2.6.1
       text.CompressWhitespace();
       ShowStatus(PresContext(), text);
     }
   }
 }
 void
 nsMathMLmactionFrame::MouseOut()
 {
   // see if we should remove the status message
   if (NS_MATHML_ACTION_TYPE_STATUSLINE == mActionType) {
     nsAutoString value;
     value.SetLength(0);
     ShowStatus(PresContext(), value);
   }
 }
 void
 nsMathMLmactionFrame::MouseClick()
 {
   if (NS_MATHML_ACTION_TYPE_TOGGLE == mActionType) {
     if (mChildCount > 1) {
       int32_t selection = (mSelection == mChildCount)? 1 : mSelection + 1;
       nsAutoString value;
       char cbuf[10];
       PR_snprintf(cbuf, sizeof(cbuf), "%d", selection);
       value.AssignASCII(cbuf);
       bool notify = false; // don't yet notify the document
       mContent->SetAttr(kNameSpaceID_None, nsGkAtoms::selection_, value, notify);
       // Now trigger a content-changed reflow...
       PresContext()->PresShell()->
         FrameNeedsReflow(mSelectedFrame, nsIPresShell::eTreeChange,
                          NS_FRAME_IS_DIRTY);
     }
   }
 }

The Tor Browser / annotate

layout/mathml/nsMathMLmactionFrame.cpp@97036ab72558 (annotated)

layout/mathml/nsMathMLmactionFrame.cpp