The Tor Browser: layout/xul/nsTextBoxFrame.cpp@97036ab72558 (annotated)

layout/xul/nsTextBoxFrame.cpp@97036ab72558 (annotated)

layout/xul/nsTextBoxFrame.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 "nsTextBoxFrame.h"
 #include "nsReadableUtils.h"
 #include "nsCOMPtr.h"
 #include "nsGkAtoms.h"
 #include "nsPresContext.h"
 #include "nsRenderingContext.h"
 #include "nsStyleContext.h"
 #include "nsIContent.h"
 #include "nsNameSpaceManager.h"
 #include "nsBoxLayoutState.h"
 #include "nsMenuBarListener.h"
 #include "nsXPIDLString.h"
 #include "nsIServiceManager.h"
 #include "nsIDOMElement.h"
 #include "nsIDOMXULLabelElement.h"
 #include "mozilla/EventStateManager.h"
 #include "nsITheme.h"
 #include "nsUnicharUtils.h"
 #include "nsContentUtils.h"
 #include "nsCxPusher.h"
 #include "nsDisplayList.h"
 #include "nsCSSRendering.h"
 #include "nsIReflowCallback.h"
 #include "nsBoxFrame.h"
 #include "mozilla/Preferences.h"
 #include "nsLayoutUtils.h"
 #include "mozilla/Attributes.h"
 #ifdef ACCESSIBILITY
 #include "nsAccessibilityService.h"
 #endif
 #include "nsBidiUtils.h"
 #include "nsBidiPresUtils.h"
 using namespace mozilla;
 class nsAccessKeyInfo
 {
 public:
     int32_t mAccesskeyIndex;
     nscoord mBeforeWidth, mAccessWidth, mAccessUnderlineSize, mAccessOffset;
 };
 bool nsTextBoxFrame::gAlwaysAppendAccessKey          = false;
 bool nsTextBoxFrame::gAccessKeyPrefInitialized       = false;
 bool nsTextBoxFrame::gInsertSeparatorBeforeAccessKey = false;
 bool nsTextBoxFrame::gInsertSeparatorPrefInitialized = false;
 nsIFrame*
 NS_NewTextBoxFrame (nsIPresShell* aPresShell, nsStyleContext* aContext)
 {
     return new (aPresShell) nsTextBoxFrame (aPresShell, aContext);
 }
 NS_IMPL_FRAMEARENA_HELPERS(nsTextBoxFrame)
 NS_QUERYFRAME_HEAD(nsTextBoxFrame)
   NS_QUERYFRAME_ENTRY(nsTextBoxFrame)
 NS_QUERYFRAME_TAIL_INHERITING(nsTextBoxFrameSuper)
 nsresult
 nsTextBoxFrame::AttributeChanged(int32_t         aNameSpaceID,
                                  nsIAtom*        aAttribute,
                                  int32_t         aModType)
 {
     bool aResize;
     bool aRedraw;
     UpdateAttributes(aAttribute, aResize, aRedraw);
     if (aResize) {
         PresContext()->PresShell()->
             FrameNeedsReflow(this, nsIPresShell::eStyleChange,
                              NS_FRAME_IS_DIRTY);
     } else if (aRedraw) {
         nsBoxLayoutState state(PresContext());
         Redraw(state);
     }
     // If the accesskey changed, register for the new value
     // The old value has been unregistered in nsXULElement::SetAttr
     if (aAttribute == nsGkAtoms::accesskey || aAttribute == nsGkAtoms::control)
         RegUnregAccessKey(true);
     return NS_OK;
 }
 nsTextBoxFrame::nsTextBoxFrame(nsIPresShell* aShell, nsStyleContext* aContext):
   nsLeafBoxFrame(aShell, aContext), mAccessKeyInfo(nullptr), mCropType(CropRight),
   mNeedsReflowCallback(false)
 {
     MarkIntrinsicWidthsDirty();
 }
 nsTextBoxFrame::~nsTextBoxFrame()
 {
     delete mAccessKeyInfo;
 }
 void
 nsTextBoxFrame::Init(nsIContent*      aContent,
                      nsIFrame*        aParent,
                      nsIFrame*        aPrevInFlow)
 {
     nsTextBoxFrameSuper::Init(aContent, aParent, aPrevInFlow);
     bool aResize;
     bool aRedraw;
     UpdateAttributes(nullptr, aResize, aRedraw); /* update all */
     // register access key
     RegUnregAccessKey(true);
 }
 void
 nsTextBoxFrame::DestroyFrom(nsIFrame* aDestructRoot)
 {
     // unregister access key
     RegUnregAccessKey(false);
     nsTextBoxFrameSuper::DestroyFrom(aDestructRoot);
 }
 bool
 nsTextBoxFrame::AlwaysAppendAccessKey()
 {
   if (!gAccessKeyPrefInitialized)
   {
     gAccessKeyPrefInitialized = true;
     const char* prefName = "intl.menuitems.alwaysappendaccesskeys";
     nsAdoptingString val = Preferences::GetLocalizedString(prefName);
     gAlwaysAppendAccessKey = val.Equals(NS_LITERAL_STRING("true"));
   }
   return gAlwaysAppendAccessKey;
 }
 bool
 nsTextBoxFrame::InsertSeparatorBeforeAccessKey()
 {
   if (!gInsertSeparatorPrefInitialized)
   {
     gInsertSeparatorPrefInitialized = true;
     const char* prefName = "intl.menuitems.insertseparatorbeforeaccesskeys";
     nsAdoptingString val = Preferences::GetLocalizedString(prefName);
     gInsertSeparatorBeforeAccessKey = val.EqualsLiteral("true");
   }
   return gInsertSeparatorBeforeAccessKey;
 }
 class nsAsyncAccesskeyUpdate MOZ_FINAL : public nsIReflowCallback
 {
 public:
     nsAsyncAccesskeyUpdate(nsIFrame* aFrame) : mWeakFrame(aFrame)
     {
     }
     virtual bool ReflowFinished() MOZ_OVERRIDE
     {
         bool shouldFlush = false;
         nsTextBoxFrame* frame =
             static_cast<nsTextBoxFrame*>(mWeakFrame.GetFrame());
         if (frame) {
             shouldFlush = frame->UpdateAccesskey(mWeakFrame);
         }
         delete this;
         return shouldFlush;
     }
     virtual void ReflowCallbackCanceled() MOZ_OVERRIDE
     {
         delete this;
     }
     nsWeakFrame mWeakFrame;
 };
 bool
 nsTextBoxFrame::UpdateAccesskey(nsWeakFrame& aWeakThis)
 {
     nsAutoString accesskey;
     nsCOMPtr<nsIDOMXULLabelElement> labelElement = do_QueryInterface(mContent);
     NS_ENSURE_TRUE(aWeakThis.IsAlive(), false);
     if (labelElement) {
         // Accesskey may be stored on control.
         // Because this method is called by the reflow callback, current context
         // may not be the right one. Pushing the context of mContent so that
         // if nsIDOMXULLabelElement is implemented in XBL, we don't get a
         // security exception.
         nsCxPusher cx;
         if (cx.Push(mContent)) {
           labelElement->GetAccessKey(accesskey);
           NS_ENSURE_TRUE(aWeakThis.IsAlive(), false);
         }
     }
     else {
         mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::accesskey, accesskey);
     }
     if (!accesskey.Equals(mAccessKey)) {
         // Need to get clean mTitle.
         mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::value, mTitle);
         mAccessKey = accesskey;
         UpdateAccessTitle();
         PresContext()->PresShell()->
             FrameNeedsReflow(this, nsIPresShell::eStyleChange,
                              NS_FRAME_IS_DIRTY);
         return true;
     }
     return false;
 }
 void
 nsTextBoxFrame::UpdateAttributes(nsIAtom*         aAttribute,
                                  bool&          aResize,
                                  bool&          aRedraw)
 {
     bool doUpdateTitle = false;
     aResize = false;
     aRedraw = false;
     if (aAttribute == nullptr || aAttribute == nsGkAtoms::crop) {
         static nsIContent::AttrValuesArray strings[] =
           {&nsGkAtoms::left, &nsGkAtoms::start, &nsGkAtoms::center,
            &nsGkAtoms::right, &nsGkAtoms::end, nullptr};
         CroppingStyle cropType;
         switch (mContent->FindAttrValueIn(kNameSpaceID_None, nsGkAtoms::crop,
                                           strings, eCaseMatters)) {
           case 0:
           case 1:
             cropType = CropLeft;
             break;
           case 2:
             cropType = CropCenter;
             break;
           case 3:
           case 4:
             cropType = CropRight;
             break;
           default:
             cropType = CropNone;
             break;
         }
         if (cropType != mCropType) {
             aResize = true;
             mCropType = cropType;
         }
     }
     if (aAttribute == nullptr || aAttribute == nsGkAtoms::value) {
         mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::value, mTitle);
         doUpdateTitle = true;
     }
     if (aAttribute == nullptr || aAttribute == nsGkAtoms::accesskey) {
         mNeedsReflowCallback = true;
         // Ensure that layout is refreshed and reflow callback called.
         aResize = true;
     }
     if (doUpdateTitle) {
         UpdateAccessTitle();
         aResize = true;
     }
 }
 class nsDisplayXULTextBox : public nsDisplayItem {
 public:
   nsDisplayXULTextBox(nsDisplayListBuilder* aBuilder,
                       nsTextBoxFrame* aFrame) :
     nsDisplayItem(aBuilder, aFrame),
     mDisableSubpixelAA(false)
   {
     MOZ_COUNT_CTOR(nsDisplayXULTextBox);
   }
 #ifdef NS_BUILD_REFCNT_LOGGING
   virtual ~nsDisplayXULTextBox() {
     MOZ_COUNT_DTOR(nsDisplayXULTextBox);
   }
 #endif
   virtual void Paint(nsDisplayListBuilder* aBuilder,
                      nsRenderingContext* aCtx) MOZ_OVERRIDE;
   virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder,
                            bool* aSnap) MOZ_OVERRIDE;
   NS_DISPLAY_DECL_NAME("XULTextBox", TYPE_XUL_TEXT_BOX)
   virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE;
   virtual void DisableComponentAlpha() MOZ_OVERRIDE {
     mDisableSubpixelAA = true;
   }
   void PaintTextToContext(nsRenderingContext* aCtx,
                           nsPoint aOffset,
                           const nscolor* aColor);
   bool mDisableSubpixelAA;
 };
 static void
 PaintTextShadowCallback(nsRenderingContext* aCtx,
                         nsPoint aShadowOffset,
                         const nscolor& aShadowColor,
                         void* aData)
 {
   reinterpret_cast<nsDisplayXULTextBox*>(aData)->
            PaintTextToContext(aCtx, aShadowOffset, &aShadowColor);
 }
 void
 nsDisplayXULTextBox::Paint(nsDisplayListBuilder* aBuilder,
                            nsRenderingContext* aCtx)
 {
   gfxContextAutoDisableSubpixelAntialiasing disable(aCtx->ThebesContext(),
                                                     mDisableSubpixelAA);
   // Paint the text shadow before doing any foreground stuff
   nsRect drawRect = static_cast<nsTextBoxFrame*>(mFrame)->mTextDrawRect +
                     ToReferenceFrame();
   nsLayoutUtils::PaintTextShadow(mFrame, aCtx,
                                  drawRect, mVisibleRect,
                                  mFrame->StyleColor()->mColor,
                                  PaintTextShadowCallback,
                                  (void*)this);
   PaintTextToContext(aCtx, nsPoint(0, 0), nullptr);
 }
 void
 nsDisplayXULTextBox::PaintTextToContext(nsRenderingContext* aCtx,
                                         nsPoint aOffset,
                                         const nscolor* aColor)
 {
   static_cast<nsTextBoxFrame*>(mFrame)->
     PaintTitle(*aCtx, mVisibleRect, ToReferenceFrame() + aOffset, aColor);
 }
 nsRect
 nsDisplayXULTextBox::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) {
   *aSnap = false;
   return mFrame->GetVisualOverflowRectRelativeToSelf() + ToReferenceFrame();
 }
 nsRect
 nsDisplayXULTextBox::GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder)
 {
   return static_cast<nsTextBoxFrame*>(mFrame)->GetComponentAlphaBounds() +
       ToReferenceFrame();
 }
 void
 nsTextBoxFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                  const nsRect&           aDirtyRect,
                                  const nsDisplayListSet& aLists)
 {
     if (!IsVisibleForPainting(aBuilder))
         return;
     nsLeafBoxFrame::BuildDisplayList(aBuilder, aDirtyRect, aLists);
     aLists.Content()->AppendNewToTop(new (aBuilder)
         nsDisplayXULTextBox(aBuilder, this));
 }
 void
 nsTextBoxFrame::PaintTitle(nsRenderingContext& aRenderingContext,
                            const nsRect&        aDirtyRect,
                            nsPoint              aPt,
                            const nscolor*       aOverrideColor)
 {
     if (mTitle.IsEmpty())
         return;
     DrawText(aRenderingContext, aDirtyRect, mTextDrawRect + aPt, aOverrideColor);
 }
 void
 nsTextBoxFrame::DrawText(nsRenderingContext& aRenderingContext,
                          const nsRect&       aDirtyRect,
                          const nsRect&       aTextRect,
                          const nscolor*      aOverrideColor)
 {
     nsPresContext* presContext = PresContext();
     // paint the title
     nscolor overColor;
     nscolor underColor;
     nscolor strikeColor;
     uint8_t overStyle;
     uint8_t underStyle;
     uint8_t strikeStyle;
     // Begin with no decorations
     uint8_t decorations = NS_STYLE_TEXT_DECORATION_LINE_NONE;
     // A mask of all possible decorations.
     uint8_t decorMask = NS_STYLE_TEXT_DECORATION_LINE_LINES_MASK;
     nsIFrame* f = this;
     do {  // find decoration colors
       nsStyleContext* context = f->StyleContext();
       if (!context->HasTextDecorationLines()) {
         break;
       }
       const nsStyleTextReset* styleText = context->StyleTextReset();
       if (decorMask & styleText->mTextDecorationLine) {  // a decoration defined here
         nscolor color;
         if (aOverrideColor) {
           color = *aOverrideColor;
         } else {
           bool isForeground;
           styleText->GetDecorationColor(color, isForeground);
           if (isForeground) {
             color = nsLayoutUtils::GetColor(f, eCSSProperty_color);
           }
         }
         uint8_t style = styleText->GetDecorationStyle();
         if (NS_STYLE_TEXT_DECORATION_LINE_UNDERLINE & decorMask &
               styleText->mTextDecorationLine) {
           underColor = color;
           underStyle = style;
           decorMask &= ~NS_STYLE_TEXT_DECORATION_LINE_UNDERLINE;
           decorations |= NS_STYLE_TEXT_DECORATION_LINE_UNDERLINE;
         }
         if (NS_STYLE_TEXT_DECORATION_LINE_OVERLINE & decorMask &
               styleText->mTextDecorationLine) {
           overColor = color;
           overStyle = style;
           decorMask &= ~NS_STYLE_TEXT_DECORATION_LINE_OVERLINE;
           decorations |= NS_STYLE_TEXT_DECORATION_LINE_OVERLINE;
         }
         if (NS_STYLE_TEXT_DECORATION_LINE_LINE_THROUGH & decorMask &
               styleText->mTextDecorationLine) {
           strikeColor = color;
           strikeStyle = style;
           decorMask &= ~NS_STYLE_TEXT_DECORATION_LINE_LINE_THROUGH;
           decorations |= NS_STYLE_TEXT_DECORATION_LINE_LINE_THROUGH;
         }
       }
     } while (0 != decorMask &&
              (f = nsLayoutUtils::GetParentOrPlaceholderFor(f)));
     nsRefPtr<nsFontMetrics> fontMet;
     nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fontMet));
     nscoord offset;
     nscoord size;
     nscoord ascent = fontMet->MaxAscent();
     nscoord baseline =
       presContext->RoundAppUnitsToNearestDevPixels(aTextRect.y + ascent);
     nsRefPtr<gfxContext> ctx = aRenderingContext.ThebesContext();
     gfxPoint pt(presContext->AppUnitsToGfxUnits(aTextRect.x),
                 presContext->AppUnitsToGfxUnits(aTextRect.y));
     gfxFloat width = presContext->AppUnitsToGfxUnits(aTextRect.width);
     gfxFloat ascentPixel = presContext->AppUnitsToGfxUnits(ascent);
     gfxFloat xInFrame = PresContext()->AppUnitsToGfxUnits(mTextDrawRect.x);
     gfxRect dirtyRect(presContext->AppUnitsToGfxUnits(aDirtyRect));
     // Underlines are drawn before overlines, and both before the text
     // itself, per http://www.w3.org/TR/CSS21/zindex.html point 7.2.1.4.1.1.
     // (We don't apply this rule to the access-key underline because we only
     // find out where that is as a side effect of drawing the text, in the
     // general case -- see below.)
     if (decorations & (NS_FONT_DECORATION_OVERLINE |
                        NS_FONT_DECORATION_UNDERLINE)) {
       fontMet->GetUnderline(offset, size);
       gfxFloat offsetPixel = presContext->AppUnitsToGfxUnits(offset);
       gfxFloat sizePixel = presContext->AppUnitsToGfxUnits(size);
       if ((decorations & NS_FONT_DECORATION_UNDERLINE) &&
           underStyle != NS_STYLE_TEXT_DECORATION_STYLE_NONE) {
         nsCSSRendering::PaintDecorationLine(this, ctx, dirtyRect, underColor,
                           pt, xInFrame, gfxSize(width, sizePixel),
                           ascentPixel, offsetPixel,
                           NS_STYLE_TEXT_DECORATION_LINE_UNDERLINE, underStyle);
       }
       if ((decorations & NS_FONT_DECORATION_OVERLINE) &&
           overStyle != NS_STYLE_TEXT_DECORATION_STYLE_NONE) {
         nsCSSRendering::PaintDecorationLine(this, ctx, dirtyRect, overColor,
                           pt, xInFrame, gfxSize(width, sizePixel),
                           ascentPixel, ascentPixel,
                           NS_STYLE_TEXT_DECORATION_LINE_OVERLINE, overStyle);
       }
     }
     nsRefPtr<nsRenderingContext> refContext =
         PresContext()->PresShell()->CreateReferenceRenderingContext();
     aRenderingContext.SetFont(fontMet);
     refContext->SetFont(fontMet);
     CalculateUnderline(*refContext);
     aRenderingContext.SetColor(aOverrideColor ? *aOverrideColor : StyleColor()->mColor);
     nsresult rv = NS_ERROR_FAILURE;
     if (mState & NS_FRAME_IS_BIDI) {
       presContext->SetBidiEnabled();
       nsBidiLevel level = nsBidiPresUtils::BidiLevelFromStyle(StyleContext());
       if (mAccessKeyInfo && mAccessKeyInfo->mAccesskeyIndex != kNotFound) {
           // We let the RenderText function calculate the mnemonic's
           // underline position for us.
           nsBidiPositionResolve posResolve;
           posResolve.logicalIndex = mAccessKeyInfo->mAccesskeyIndex;
           rv = nsBidiPresUtils::RenderText(mCroppedTitle.get(), mCroppedTitle.Length(), level,
                                            presContext, aRenderingContext,
                                            *refContext,
                                            aTextRect.x, baseline,
                                            &posResolve,
 );
           mAccessKeyInfo->mBeforeWidth = posResolve.visualLeftTwips;
           mAccessKeyInfo->mAccessWidth = posResolve.visualWidth;
       }
       else
       {
           rv = nsBidiPresUtils::RenderText(mCroppedTitle.get(), mCroppedTitle.Length(), level,
                                            presContext, aRenderingContext,
                                            *refContext,
                                            aTextRect.x, baseline);
       }
     }
     if (NS_FAILED(rv)) {
        aRenderingContext.SetTextRunRTL(false);
        if (mAccessKeyInfo && mAccessKeyInfo->mAccesskeyIndex != kNotFound) {
            // In the simple (non-BiDi) case, we calculate the mnemonic's
            // underline position by getting the text metric.
            // XXX are attribute values always two byte?
            if (mAccessKeyInfo->mAccesskeyIndex > 0)
                mAccessKeyInfo->mBeforeWidth =
                    refContext->GetWidth(mCroppedTitle.get(),
                                         mAccessKeyInfo->mAccesskeyIndex);
            else
                mAccessKeyInfo->mBeforeWidth = 0;
        }
        fontMet->DrawString(mCroppedTitle.get(), mCroppedTitle.Length(),
                            aTextRect.x, baseline, &aRenderingContext,
                            refContext.get());
     }
     if (mAccessKeyInfo && mAccessKeyInfo->mAccesskeyIndex != kNotFound) {
         aRenderingContext.FillRect(aTextRect.x + mAccessKeyInfo->mBeforeWidth,
                                    aTextRect.y + mAccessKeyInfo->mAccessOffset,
                                    mAccessKeyInfo->mAccessWidth,
                                    mAccessKeyInfo->mAccessUnderlineSize);
     }
     // Strikeout is drawn on top of the text, per
     // http://www.w3.org/TR/CSS21/zindex.html point 7.2.1.4.1.1.
     if ((decorations & NS_FONT_DECORATION_LINE_THROUGH) &&
         strikeStyle != NS_STYLE_TEXT_DECORATION_STYLE_NONE) {
       fontMet->GetStrikeout(offset, size);
       gfxFloat offsetPixel = presContext->AppUnitsToGfxUnits(offset);
       gfxFloat sizePixel = presContext->AppUnitsToGfxUnits(size);
       nsCSSRendering::PaintDecorationLine(this, ctx, dirtyRect, strikeColor,
                         pt, xInFrame, gfxSize(width, sizePixel), ascentPixel,
                         offsetPixel, NS_STYLE_TEXT_DECORATION_LINE_LINE_THROUGH,
                         strikeStyle);
     }
 }
 void
 nsTextBoxFrame::CalculateUnderline(nsRenderingContext& aRenderingContext)
 {
     if (mAccessKeyInfo && mAccessKeyInfo->mAccesskeyIndex != kNotFound) {
          // Calculate all fields of mAccessKeyInfo which
          // are the same for both BiDi and non-BiDi frames.
          const char16_t *titleString = mCroppedTitle.get();
          aRenderingContext.SetTextRunRTL(false);
          mAccessKeyInfo->mAccessWidth =
              aRenderingContext.GetWidth(titleString[mAccessKeyInfo->
                                                     mAccesskeyIndex]);
          nscoord offset, baseline;
          nsFontMetrics* metrics = aRenderingContext.FontMetrics();
          metrics->GetUnderline(offset, mAccessKeyInfo->mAccessUnderlineSize);
          baseline = metrics->MaxAscent();
          mAccessKeyInfo->mAccessOffset = baseline - offset;
     }
 }
 nscoord
 nsTextBoxFrame::CalculateTitleForWidth(nsPresContext*      aPresContext,
                                        nsRenderingContext& aRenderingContext,
                                        nscoord              aWidth)
 {
     if (mTitle.IsEmpty()) {
         mCroppedTitle.Truncate();
         return 0;
     }
     nsRefPtr<nsFontMetrics> fm;
     nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
     aRenderingContext.SetFont(fm);
     // see if the text will completely fit in the width given
     nscoord titleWidth = nsLayoutUtils::GetStringWidth(this, &aRenderingContext,
                                                        mTitle.get(), mTitle.Length());
     if (titleWidth <= aWidth) {
         mCroppedTitle = mTitle;
         if (HasRTLChars(mTitle)) {
             mState |= NS_FRAME_IS_BIDI;
         }
         return titleWidth;  // fits, done.
     }
     const nsDependentString& kEllipsis = nsContentUtils::GetLocalizedEllipsis();
     // start with an ellipsis
     mCroppedTitle.Assign(kEllipsis);
     // see if the width is even smaller than the ellipsis
     // if so, clear the text (XXX set as many '.' as we can?).
     aRenderingContext.SetTextRunRTL(false);
     titleWidth = aRenderingContext.GetWidth(kEllipsis);
     if (titleWidth > aWidth) {
         mCroppedTitle.SetLength(0);
         return 0;
     }
     // if the ellipsis fits perfectly, no use in trying to insert
     if (titleWidth == aWidth)
         return titleWidth;
     aWidth -= titleWidth;
     // XXX: This whole block should probably take surrogates into account
     // XXX and clusters!
     // ok crop things
     switch (mCropType)
     {
         case CropNone:
         case CropRight:
         {
             nscoord cwidth;
             nscoord twidth = 0;
             int length = mTitle.Length();
             int i;
             for (i = 0; i < length; ++i) {
                 char16_t ch = mTitle.CharAt(i);
                 // still in LTR mode
                 cwidth = aRenderingContext.GetWidth(ch);
                 if (twidth + cwidth > aWidth)
                     break;
                 twidth += cwidth;
                 if (UCS2_CHAR_IS_BIDI(ch) ) {
                   mState |= NS_FRAME_IS_BIDI;
                 }
             }
             if (i == 0)
                 return titleWidth;
             // insert what character we can in.
             nsAutoString title( mTitle );
             title.Truncate(i);
             mCroppedTitle.Insert(title, 0);
         }
         break;
         case CropLeft:
         {
             nscoord cwidth;
             nscoord twidth = 0;
             int length = mTitle.Length();
             int i;
             for (i=length-1; i >= 0; --i) {
                 char16_t ch = mTitle.CharAt(i);
                 cwidth = aRenderingContext.GetWidth(ch);
                 if (twidth + cwidth > aWidth)
                     break;
                 twidth += cwidth;
                 if (UCS2_CHAR_IS_BIDI(ch) ) {
                   mState |= NS_FRAME_IS_BIDI;
                 }
             }
             if (i == length-1)
                 return titleWidth;
             nsAutoString copy;
             mTitle.Right(copy, length-1-i);
             mCroppedTitle += copy;
         }
         break;
         case CropCenter:
         {
             nscoord stringWidth =
                 nsLayoutUtils::GetStringWidth(this, &aRenderingContext,
                                               mTitle.get(), mTitle.Length());
             if (stringWidth <= aWidth) {
                 // the entire string will fit in the maximum width
                 mCroppedTitle.Insert(mTitle, 0);
                 break;
             }
             // determine how much of the string will fit in the max width
             nscoord charWidth = 0;
             nscoord totalWidth = 0;
             char16_t ch;
             int leftPos, rightPos;
             nsAutoString leftString, rightString;
             rightPos = mTitle.Length() - 1;
             aRenderingContext.SetTextRunRTL(false);
             for (leftPos = 0; leftPos <= rightPos;) {
                 // look at the next character on the left end
                 ch = mTitle.CharAt(leftPos);
                 charWidth = aRenderingContext.GetWidth(ch);
                 totalWidth += charWidth;
                 if (totalWidth > aWidth)
                     // greater than the allowable width
                     break;
                 leftString.Insert(ch, leftString.Length());
                 if (UCS2_CHAR_IS_BIDI(ch))
                     mState |= NS_FRAME_IS_BIDI;
                 // look at the next character on the right end
                 if (rightPos > leftPos) {
                     // haven't looked at this character yet
                     ch = mTitle.CharAt(rightPos);
                     charWidth = aRenderingContext.GetWidth(ch);
                     totalWidth += charWidth;
                     if (totalWidth > aWidth)
                         // greater than the allowable width
                         break;
                     rightString.Insert(ch, 0);
                     if (UCS2_CHAR_IS_BIDI(ch))
                         mState |= NS_FRAME_IS_BIDI;
                 }
                 // look at the next two characters
                 leftPos++;
                 rightPos--;
             }
             mCroppedTitle = leftString + kEllipsis + rightString;
         }
         break;
     }
     return nsLayoutUtils::GetStringWidth(this, &aRenderingContext,
                                          mCroppedTitle.get(), mCroppedTitle.Length());
 }
 #define OLD_ELLIPSIS NS_LITERAL_STRING("...")
 // the following block is to append the accesskey to mTitle if there is an accesskey
 // but the mTitle doesn't have the character
 void
 nsTextBoxFrame::UpdateAccessTitle()
 {
     /*
      * Note that if you change appending access key label spec,
      * you need to maintain same logic in following methods. See bug 324159.
      * toolkit/content/commonDialog.js (setLabelForNode)
      * toolkit/content/widgets/text.xml (formatAccessKey)
      */
     int32_t menuAccessKey;
     nsMenuBarListener::GetMenuAccessKey(&menuAccessKey);
     if (!menuAccessKey || mAccessKey.IsEmpty())
         return;
     if (!AlwaysAppendAccessKey() &&
         FindInReadable(mAccessKey, mTitle, nsCaseInsensitiveStringComparator()))
         return;
     nsAutoString accessKeyLabel;
     accessKeyLabel += '(';
     accessKeyLabel += mAccessKey;
     ToUpperCase(accessKeyLabel);
     accessKeyLabel += ')';
     if (mTitle.IsEmpty()) {
         mTitle = accessKeyLabel;
         return;
     }
     const nsDependentString& kEllipsis = nsContentUtils::GetLocalizedEllipsis();
     uint32_t offset = mTitle.Length();
     if (StringEndsWith(mTitle, kEllipsis)) {
         offset -= kEllipsis.Length();
     } else if (StringEndsWith(mTitle, OLD_ELLIPSIS)) {
         // Try to check with our old ellipsis (for old addons)
         offset -= OLD_ELLIPSIS.Length();
     } else {
         // Try to check with
         // our default ellipsis (for non-localized addons) or ':'
         const char16_t kLastChar = mTitle.Last();
         if (kLastChar == char16_t(0x2026) || kLastChar == char16_t(':'))
             offset--;
     }
     if (InsertSeparatorBeforeAccessKey() &&
         offset > 0 && !NS_IS_SPACE(mTitle[offset - 1])) {
         mTitle.Insert(' ', offset);
         offset++;
     }
     mTitle.Insert(accessKeyLabel, offset);
 }
 void
 nsTextBoxFrame::UpdateAccessIndex()
 {
     int32_t menuAccessKey;
     nsMenuBarListener::GetMenuAccessKey(&menuAccessKey);
     if (menuAccessKey) {
         if (mAccessKey.IsEmpty()) {
             if (mAccessKeyInfo) {
                 delete mAccessKeyInfo;
                 mAccessKeyInfo = nullptr;
             }
         } else {
             if (!mAccessKeyInfo) {
                 mAccessKeyInfo = new nsAccessKeyInfo();
                 if (!mAccessKeyInfo)
                     return;
             }
             nsAString::const_iterator start, end;
             mCroppedTitle.BeginReading(start);
             mCroppedTitle.EndReading(end);
             // remember the beginning of the string
             nsAString::const_iterator originalStart = start;
             bool found;
             if (!AlwaysAppendAccessKey()) {
                 // not appending access key - do case-sensitive search
                 // first
                 found = FindInReadable(mAccessKey, start, end);
                 if (!found) {
                     // didn't find it - perform a case-insensitive search
                     start = originalStart;
                     found = FindInReadable(mAccessKey, start, end,
                                            nsCaseInsensitiveStringComparator());
                 }
             } else {
                 found = RFindInReadable(mAccessKey, start, end,
                                         nsCaseInsensitiveStringComparator());
             }
             if (found)
                 mAccessKeyInfo->mAccesskeyIndex = Distance(originalStart, start);
             else
                 mAccessKeyInfo->mAccesskeyIndex = kNotFound;
         }
     }
 }
 NS_IMETHODIMP
 nsTextBoxFrame::DoLayout(nsBoxLayoutState& aBoxLayoutState)
 {
     if (mNeedsReflowCallback) {
         nsIReflowCallback* cb = new nsAsyncAccesskeyUpdate(this);
         if (cb) {
             PresContext()->PresShell()->PostReflowCallback(cb);
         }
         mNeedsReflowCallback = false;
     }
     nsresult rv = nsLeafBoxFrame::DoLayout(aBoxLayoutState);
     CalcDrawRect(*aBoxLayoutState.GetRenderingContext());
     const nsStyleText* textStyle = StyleText();
     nsRect scrollBounds(nsPoint(0, 0), GetSize());
     nsRect textRect = mTextDrawRect;
     nsRefPtr<nsFontMetrics> fontMet;
     nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fontMet));
     nsBoundingMetrics metrics =
       fontMet->GetInkBoundsForVisualOverflow(mCroppedTitle.get(),
                                              mCroppedTitle.Length(),
                                              aBoxLayoutState.GetRenderingContext());
     textRect.x -= metrics.leftBearing;
     textRect.width = metrics.width;
     // In DrawText() we always draw with the baseline at MaxAscent() (relative to mTextDrawRect),
     textRect.y += fontMet->MaxAscent() - metrics.ascent;
     textRect.height = metrics.ascent + metrics.descent;
     // Our scrollable overflow is our bounds; our visual overflow may
     // extend beyond that.
     nsRect visualBounds;
     visualBounds.UnionRect(scrollBounds, textRect);
     nsOverflowAreas overflow(visualBounds, scrollBounds);
     if (textStyle->mTextShadow) {
       // text-shadow extends our visual but not scrollable bounds
       nsRect &vis = overflow.VisualOverflow();
       vis.UnionRect(vis, nsLayoutUtils::GetTextShadowRectsUnion(mTextDrawRect, this));
     }
     FinishAndStoreOverflow(overflow, GetSize());
     return rv;
 }
 nsRect
 nsTextBoxFrame::GetComponentAlphaBounds()
 {
   if (StyleText()->mTextShadow) {
     return GetVisualOverflowRectRelativeToSelf();
   }
   return mTextDrawRect;
 }
 bool
 nsTextBoxFrame::ComputesOwnOverflowArea()
 {
     return true;
 }
 /* virtual */ void
 nsTextBoxFrame::MarkIntrinsicWidthsDirty()
 {
     mNeedsRecalc = true;
     nsTextBoxFrameSuper::MarkIntrinsicWidthsDirty();
 }
 void
 nsTextBoxFrame::GetTextSize(nsPresContext* aPresContext,
                             nsRenderingContext& aRenderingContext,
                             const nsString& aString,
                             nsSize& aSize, nscoord& aAscent)
 {
     nsRefPtr<nsFontMetrics> fontMet;
     nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fontMet));
     aSize.height = fontMet->MaxHeight();
     aRenderingContext.SetFont(fontMet);
     aSize.width =
       nsLayoutUtils::GetStringWidth(this, &aRenderingContext,
                                     aString.get(), aString.Length());
     aAscent = fontMet->MaxAscent();
 }
 void
 nsTextBoxFrame::CalcTextSize(nsBoxLayoutState& aBoxLayoutState)
 {
     if (mNeedsRecalc)
     {
         nsSize size;
         nsPresContext* presContext = aBoxLayoutState.PresContext();
         nsRenderingContext* rendContext = aBoxLayoutState.GetRenderingContext();
         if (rendContext) {
             GetTextSize(presContext, *rendContext,
                         mTitle, size, mAscent);
             mTextSize = size;
             mNeedsRecalc = false;
         }
     }
 }
 void
 nsTextBoxFrame::CalcDrawRect(nsRenderingContext &aRenderingContext)
 {
     nsRect textRect(nsPoint(0, 0), GetSize());
     nsMargin borderPadding;
     GetBorderAndPadding(borderPadding);
     textRect.Deflate(borderPadding);
     // determine (cropped) title and underline position
     nsPresContext* presContext = PresContext();
     // determine (cropped) title which fits in aRect.width and its width
     nscoord titleWidth =
         CalculateTitleForWidth(presContext, aRenderingContext, textRect.width);
 #ifdef ACCESSIBILITY
     // Make sure to update the accessible tree in case when cropped title is
     // changed.
     nsAccessibilityService* accService = GetAccService();
     if (accService) {
         accService->UpdateLabelValue(PresContext()->PresShell(), mContent,
                                      mCroppedTitle);
     }
 #endif
     // determine if and at which position to put the underline
     UpdateAccessIndex();
     // make the rect as small as our (cropped) text.
     nscoord outerWidth = textRect.width;
     textRect.width = titleWidth;
     // Align our text within the overall rect by checking our text-align property.
     const nsStyleVisibility* vis = StyleVisibility();
     const nsStyleText* textStyle = StyleText();
     if (textStyle->mTextAlign == NS_STYLE_TEXT_ALIGN_CENTER)
       textRect.x += (outerWidth - textRect.width)/2;
     else if (textStyle->mTextAlign == NS_STYLE_TEXT_ALIGN_RIGHT ||
              (textStyle->mTextAlign == NS_STYLE_TEXT_ALIGN_DEFAULT &&
               vis->mDirection == NS_STYLE_DIRECTION_RTL) ||
              (textStyle->mTextAlign == NS_STYLE_TEXT_ALIGN_END &&
               vis->mDirection == NS_STYLE_DIRECTION_LTR)) {
       textRect.x += (outerWidth - textRect.width);
     }
     mTextDrawRect = textRect;
 }
 /**
  * Ok return our dimensions
  */
 nsSize
 nsTextBoxFrame::GetPrefSize(nsBoxLayoutState& aBoxLayoutState)
 {
     CalcTextSize(aBoxLayoutState);
     nsSize size = mTextSize;
     DISPLAY_PREF_SIZE(this, size);
     AddBorderAndPadding(size);
     bool widthSet, heightSet;
     nsIFrame::AddCSSPrefSize(this, size, widthSet, heightSet);
     return size;
 }
 /**
  * Ok return our dimensions
  */
 nsSize
 nsTextBoxFrame::GetMinSize(nsBoxLayoutState& aBoxLayoutState)
 {
     CalcTextSize(aBoxLayoutState);
     nsSize size = mTextSize;
     DISPLAY_MIN_SIZE(this, size);
     // if there is cropping our min width becomes our border and padding
     if (mCropType != CropNone)
         size.width = 0;
     AddBorderAndPadding(size);
     bool widthSet, heightSet;
     nsIFrame::AddCSSMinSize(aBoxLayoutState, this, size, widthSet, heightSet);
     return size;
 }
 nscoord
 nsTextBoxFrame::GetBoxAscent(nsBoxLayoutState& aBoxLayoutState)
 {
     CalcTextSize(aBoxLayoutState);
     nscoord ascent = mAscent;
     nsMargin m(0,0,0,0);
     GetBorderAndPadding(m);
     ascent += m.top;
     return ascent;
 }
 #ifdef DEBUG_FRAME_DUMP
 nsresult
 nsTextBoxFrame::GetFrameName(nsAString& aResult) const
 {
     MakeFrameName(NS_LITERAL_STRING("TextBox"), aResult);
     aResult += NS_LITERAL_STRING("[value=") + mTitle + NS_LITERAL_STRING("]");
     return NS_OK;
 }
 #endif
 // If you make changes to this function, check its counterparts
 // in nsBoxFrame and nsXULLabelFrame
 nsresult
 nsTextBoxFrame::RegUnregAccessKey(bool aDoReg)
 {
     // if we have no content, we can't do anything
     if (!mContent)
         return NS_ERROR_FAILURE;
     // check if we have a |control| attribute
     // do this check first because few elements have control attributes, and we
     // can weed out most of the elements quickly.
     // XXXjag a side-effect is that we filter out anonymous <label>s
     // in e.g. <menu>, <menuitem>, <button>. These <label>s inherit
     // |accesskey| and would otherwise register themselves, overwriting
     // the content we really meant to be registered.
     if (!mContent->HasAttr(kNameSpaceID_None, nsGkAtoms::control))
         return NS_OK;
     // see if we even have an access key
     nsAutoString accessKey;
     mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::accesskey, accessKey);
     if (accessKey.IsEmpty())
         return NS_OK;
     // With a valid PresContext we can get the ESM
     // and (un)register the access key
     EventStateManager* esm = PresContext()->EventStateManager();
     uint32_t key = accessKey.First();
     if (aDoReg)
         esm->RegisterAccessKey(mContent, key);
     else
         esm->UnregisterAccessKey(mContent, key);
     return NS_OK;
 }

The Tor Browser / annotate

layout/xul/nsTextBoxFrame.cpp@97036ab72558 (annotated)

layout/xul/nsTextBoxFrame.cpp