The Tor Browser: layout/mathml/nsMathMLmfencedFrame.cpp@ac0c01689b40 (annotated)

layout/mathml/nsMathMLmfencedFrame.cpp@ac0c01689b40 (annotated)

layout/mathml/nsMathMLmfencedFrame.cpp

Thu, 15 Jan 2015 15:59:08 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 15:59:08 +0100
branch: TOR_BUG_9701
changeset 10: ac0c01689b40
permissions: -rw-r--r--

Implement a real Private Browsing Mode condition by changing the API/ABI;
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 "nsMathMLmfencedFrame.h"
 #include "nsRenderingContext.h"
 #include "nsMathMLChar.h"
 #include <algorithm>
 //
 // <mfenced> -- surround content with a pair of fences
 //
 nsIFrame*
 NS_NewMathMLmfencedFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 {
   return new (aPresShell) nsMathMLmfencedFrame(aContext);
 }
 NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmfencedFrame)
 nsMathMLmfencedFrame::~nsMathMLmfencedFrame()
 {
   RemoveFencesAndSeparators();
 }
 NS_IMETHODIMP
 nsMathMLmfencedFrame::InheritAutomaticData(nsIFrame* aParent)
 {
   // let the base class get the default from our parent
   nsMathMLContainerFrame::InheritAutomaticData(aParent);
   mPresentationData.flags |= NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY;
   RemoveFencesAndSeparators();
   CreateFencesAndSeparators(PresContext());
   return NS_OK;
 }
 nsresult
 nsMathMLmfencedFrame::SetInitialChildList(ChildListID     aListID,
                                           nsFrameList&    aChildList)
 {
   // First, let the base class do its work
   nsresult rv = nsMathMLContainerFrame::SetInitialChildList(aListID, aChildList);
   if (NS_FAILED(rv)) return rv;
   // InheritAutomaticData will not get called if our parent is not a mathml
   // frame, so initialize NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY for
   // GetPreferredStretchSize() from Reflow().
   mPresentationData.flags |= NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY;
   // No need to track the style contexts given to our MathML chars.
   // The Style System will use Get/SetAdditionalStyleContext() to keep them
   // up-to-date if dynamic changes arise.
   CreateFencesAndSeparators(PresContext());
   return NS_OK;
 }
 nsresult
 nsMathMLmfencedFrame::AttributeChanged(int32_t         aNameSpaceID,
                                        nsIAtom*        aAttribute,
                                        int32_t         aModType)
 {
   RemoveFencesAndSeparators();
   CreateFencesAndSeparators(PresContext());
   return nsMathMLContainerFrame::
          AttributeChanged(aNameSpaceID, aAttribute, aModType);
 }
 nsresult
 nsMathMLmfencedFrame::ChildListChanged(int32_t aModType)
 {
   RemoveFencesAndSeparators();
   CreateFencesAndSeparators(PresContext());
   return nsMathMLContainerFrame::ChildListChanged(aModType);
 }
 void
 nsMathMLmfencedFrame::RemoveFencesAndSeparators()
 {
   delete mOpenChar;
   delete mCloseChar;
   if (mSeparatorsChar) delete[] mSeparatorsChar;
   mOpenChar = nullptr;
   mCloseChar = nullptr;
   mSeparatorsChar = nullptr;
   mSeparatorsCount = 0;
 }
 void
 nsMathMLmfencedFrame::CreateFencesAndSeparators(nsPresContext* aPresContext)
 {
   nsAutoString value;
   //////////////
   // see if the opening fence is there ...
   if (!mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::open, value)) {
     value = char16_t('('); // default as per the MathML REC
   } else {
     value.CompressWhitespace();
   }
   if (!value.IsEmpty()) {
     mOpenChar = new nsMathMLChar;
     mOpenChar->SetData(aPresContext, value);
     ResolveMathMLCharStyle(aPresContext, mContent, mStyleContext, mOpenChar);
   }
   //////////////
   // see if the closing fence is there ...
   if(!mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::close, value)) {
     value = char16_t(')'); // default as per the MathML REC
   } else {
     value.CompressWhitespace();
   }
   if (!value.IsEmpty()) {
     mCloseChar = new nsMathMLChar;
     mCloseChar->SetData(aPresContext, value);
     ResolveMathMLCharStyle(aPresContext, mContent, mStyleContext, mCloseChar);
   }
   //////////////
   // see if separators are there ...
   if (!mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::separators_, value)) {
     value = char16_t(','); // default as per the MathML REC
   } else {
     value.StripWhitespace();
   }
   mSeparatorsCount = value.Length();
   if (0 < mSeparatorsCount) {
     int32_t sepCount = mFrames.GetLength() - 1;
     if (0 < sepCount) {
       mSeparatorsChar = new nsMathMLChar[sepCount];
       nsAutoString sepChar;
       for (int32_t i = 0; i < sepCount; i++) {
         if (i < mSeparatorsCount) {
           sepChar = value[i];
         }
         else {
           sepChar = value[mSeparatorsCount-1];
         }
         mSeparatorsChar[i].SetData(aPresContext, sepChar);
         ResolveMathMLCharStyle(aPresContext, mContent, mStyleContext, &mSeparatorsChar[i]);
       }
       mSeparatorsCount = sepCount;
     } else {
       // No separators.  Note that sepCount can be -1 here, so don't
       // set mSeparatorsCount to it.
       mSeparatorsCount = 0;
     }
   }
 }
 void
 nsMathMLmfencedFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                        const nsRect&           aDirtyRect,
                                        const nsDisplayListSet& aLists)
 {
   /////////////
   // display the content
   nsMathMLContainerFrame::BuildDisplayList(aBuilder, aDirtyRect, aLists);
   ////////////
   // display fences and separators
   uint32_t count = 0;
   if (mOpenChar) {
     mOpenChar->Display(aBuilder, this, aLists, count++);
   }
   if (mCloseChar) {
     mCloseChar->Display(aBuilder, this, aLists, count++);
   }
   for (int32_t i = 0; i < mSeparatorsCount; i++) {
     mSeparatorsChar[i].Display(aBuilder, this, aLists, count++);
   }
 }
 nsresult
 nsMathMLmfencedFrame::Reflow(nsPresContext*          aPresContext,
                              nsHTMLReflowMetrics&     aDesiredSize,
                              const nsHTMLReflowState& aReflowState,
                              nsReflowStatus&          aStatus)
 {
   nsresult rv;
   aDesiredSize.Width() = aDesiredSize.Height() = 0;
   aDesiredSize.SetTopAscent(0);
   aDesiredSize.mBoundingMetrics = nsBoundingMetrics();
   int32_t i;
   const nsStyleFont* font = StyleFont();
   nsRefPtr<nsFontMetrics> fm;
   nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
   aReflowState.rendContext->SetFont(fm);
   nscoord axisHeight, em;
   GetAxisHeight(*aReflowState.rendContext, fm, axisHeight);
   GetEmHeight(fm, em);
   // leading to be left at the top and the bottom of stretched chars
   nscoord leading = NSToCoordRound(0.2f * em);
   /////////////
   // Reflow children
   // Asking each child to cache its bounding metrics
   // Note that we don't use the base method nsMathMLContainerFrame::Reflow()
   // because we want to stretch our fences, separators and stretchy frames using
   // the *same* initial aDesiredSize.mBoundingMetrics. If we were to use the base
   // method here, our stretchy frames will be stretched and placed, and we may
   // end up stretching our fences/separators with a different aDesiredSize.
   // XXX The above decision was revisited in bug 121748 and this code can be
   // refactored to use nsMathMLContainerFrame::Reflow() at some stage.
   nsReflowStatus childStatus;
   nsSize availSize(aReflowState.ComputedWidth(), NS_UNCONSTRAINEDSIZE);
   nsIFrame* firstChild = GetFirstPrincipalChild();
   nsIFrame* childFrame = firstChild;
   nscoord ascent = 0, descent = 0;
   if (firstChild || mOpenChar || mCloseChar || mSeparatorsCount > 0) {
     // We use the ASCII metrics to get our minimum height. This way,
     // if we have borders or a background, they will fit better with
     // other elements on the line.
     ascent = fm->MaxAscent();
     descent = fm->MaxDescent();
   }
   while (childFrame) {
     nsHTMLReflowMetrics childDesiredSize(aReflowState,
                                          aDesiredSize.mFlags
                                          | NS_REFLOW_CALC_BOUNDING_METRICS);
     nsHTMLReflowState childReflowState(aPresContext, aReflowState,
                                        childFrame, availSize);
     rv = ReflowChild(childFrame, aPresContext, childDesiredSize,
                      childReflowState, childStatus);
     //NS_ASSERTION(NS_FRAME_IS_COMPLETE(childStatus), "bad status");
     if (NS_FAILED(rv)) {
       // Call DidReflow() for the child frames we successfully did reflow.
       DidReflowChildren(firstChild, childFrame);
       return rv;
     }
     SaveReflowAndBoundingMetricsFor(childFrame, childDesiredSize,
                                     childDesiredSize.mBoundingMetrics);
     nscoord childDescent = childDesiredSize.Height() - childDesiredSize.TopAscent();
     if (descent < childDescent)
       descent = childDescent;
     if (ascent < childDesiredSize.TopAscent())
       ascent = childDesiredSize.TopAscent();
     childFrame = childFrame->GetNextSibling();
   }
   /////////////
   // Ask stretchy children to stretch themselves
   nsBoundingMetrics containerSize;
   nsStretchDirection stretchDir = NS_STRETCH_DIRECTION_VERTICAL;
   GetPreferredStretchSize(*aReflowState.rendContext,
 , /* i.e., without embellishments */
                           stretchDir, containerSize);
   childFrame = firstChild;
   while (childFrame) {
     nsIMathMLFrame* mathmlChild = do_QueryFrame(childFrame);
     if (mathmlChild) {
       nsHTMLReflowMetrics childDesiredSize(aReflowState);
       // retrieve the metrics that was stored at the previous pass
       GetReflowAndBoundingMetricsFor(childFrame, childDesiredSize,
                                      childDesiredSize.mBoundingMetrics);
       mathmlChild->Stretch(*aReflowState.rendContext,
                            stretchDir, containerSize, childDesiredSize);
       // store the updated metrics
       SaveReflowAndBoundingMetricsFor(childFrame, childDesiredSize,
                                       childDesiredSize.mBoundingMetrics);
       nscoord childDescent = childDesiredSize.Height() - childDesiredSize.TopAscent();
       if (descent < childDescent)
         descent = childDescent;
       if (ascent < childDesiredSize.TopAscent())
         ascent = childDesiredSize.TopAscent();
     }
     childFrame = childFrame->GetNextSibling();
   }
   // bug 121748: for surrounding fences & separators, use a size that covers everything
   GetPreferredStretchSize(*aReflowState.rendContext,
                           STRETCH_CONSIDER_EMBELLISHMENTS,
                           stretchDir, containerSize);
   //////////////////////////////////////////
   // Prepare the opening fence, separators, and closing fence, and
   // adjust the origin of children.
   // we need to center around the axis
   nscoord delta = std::max(containerSize.ascent - axisHeight,
                          containerSize.descent + axisHeight);
   containerSize.ascent = delta + axisHeight;
   containerSize.descent = delta - axisHeight;
   bool isRTL = StyleVisibility()->mDirection;
   /////////////////
   // opening fence ...
   ReflowChar(aPresContext, *aReflowState.rendContext, mOpenChar,
              NS_MATHML_OPERATOR_FORM_PREFIX, font->mScriptLevel,
              axisHeight, leading, em, containerSize, ascent, descent, isRTL);
   /////////////////
   // separators ...
   for (i = 0; i < mSeparatorsCount; i++) {
     ReflowChar(aPresContext, *aReflowState.rendContext, &mSeparatorsChar[i],
                NS_MATHML_OPERATOR_FORM_INFIX, font->mScriptLevel,
                axisHeight, leading, em, containerSize, ascent, descent, isRTL);
   }
   /////////////////
   // closing fence ...
   ReflowChar(aPresContext, *aReflowState.rendContext, mCloseChar,
              NS_MATHML_OPERATOR_FORM_POSTFIX, font->mScriptLevel,
              axisHeight, leading, em, containerSize, ascent, descent, isRTL);
   //////////////////
   // Adjust the origins of each child.
   // and update our bounding metrics
   i = 0;
   nscoord dx = 0;
   nsBoundingMetrics bm;
   bool firstTime = true;
   nsMathMLChar *leftChar, *rightChar;
   if (isRTL) {
     leftChar = mCloseChar;
     rightChar = mOpenChar;
   } else {
     leftChar = mOpenChar;
     rightChar = mCloseChar;
   }
   if (leftChar) {
     PlaceChar(leftChar, ascent, bm, dx);
     aDesiredSize.mBoundingMetrics = bm;
     firstTime = false;
   }
   if (isRTL) {
     childFrame = this->GetLastChild(nsIFrame::kPrincipalList);
   } else {
     childFrame = firstChild;
   }
   while (childFrame) {
     nsHTMLReflowMetrics childSize(aReflowState);
     GetReflowAndBoundingMetricsFor(childFrame, childSize, bm);
     if (firstTime) {
       firstTime = false;
       aDesiredSize.mBoundingMetrics  = bm;
     }
     else
       aDesiredSize.mBoundingMetrics += bm;
     FinishReflowChild(childFrame, aPresContext, childSize, nullptr,
                       dx, ascent - childSize.TopAscent(), 0);
     dx += childSize.Width();
     if (i < mSeparatorsCount) {
       PlaceChar(&mSeparatorsChar[isRTL ? mSeparatorsCount - 1 - i : i],
                 ascent, bm, dx);
       aDesiredSize.mBoundingMetrics += bm;
     }
     i++;
     if (isRTL) {
       childFrame = childFrame->GetPrevSibling();
     } else {
       childFrame = childFrame->GetNextSibling();
     }
   }
   if (rightChar) {
     PlaceChar(rightChar, ascent, bm, dx);
     if (firstTime)
       aDesiredSize.mBoundingMetrics  = bm;
     else
       aDesiredSize.mBoundingMetrics += bm;
   }
   aDesiredSize.Width() = aDesiredSize.mBoundingMetrics.width;
   aDesiredSize.Height() = ascent + descent;
   aDesiredSize.SetTopAscent(ascent);
   SetBoundingMetrics(aDesiredSize.mBoundingMetrics);
   SetReference(nsPoint(0, aDesiredSize.TopAscent()));
   // see if we should fix the spacing
   FixInterFrameSpacing(aDesiredSize);
   // Finished with these:
   ClearSavedChildMetrics();
   // Set our overflow area
   GatherAndStoreOverflow(&aDesiredSize);
   aStatus = NS_FRAME_COMPLETE;
   NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
   return NS_OK;
 }
 static void
 GetCharSpacing(nsMathMLChar*        aMathMLChar,
                nsOperatorFlags      aForm,
                int32_t              aScriptLevel,
                nscoord              em,
                nscoord&             aLeftSpace,
                nscoord&             aRightSpace)
 {
   nsAutoString data;
   aMathMLChar->GetData(data);
   nsOperatorFlags flags = 0;
   float lspace = 0.0f;
   float rspace = 0.0f;
   bool found = nsMathMLOperators::LookupOperator(data, aForm,
                                                    &flags, &lspace, &rspace);
   // We don't want extra space when we are a script
   if (found && aScriptLevel > 0) {
     lspace /= 2.0f;
     rspace /= 2.0f;
   }
   aLeftSpace = NSToCoordRound(lspace * em);
   aRightSpace = NSToCoordRound(rspace * em);
 }
 // helper functions to perform the common task of formatting our chars
 /*static*/ nsresult
 nsMathMLmfencedFrame::ReflowChar(nsPresContext*      aPresContext,
                                  nsRenderingContext& aRenderingContext,
                                  nsMathMLChar*        aMathMLChar,
                                  nsOperatorFlags      aForm,
                                  int32_t              aScriptLevel,
                                  nscoord              axisHeight,
                                  nscoord              leading,
                                  nscoord              em,
                                  nsBoundingMetrics&   aContainerSize,
                                  nscoord&             aAscent,
                                  nscoord&             aDescent,
                                  bool                 aRTL)
 {
   if (aMathMLChar && 0 < aMathMLChar->Length()) {
     nscoord leftSpace;
     nscoord rightSpace;
     GetCharSpacing(aMathMLChar, aForm, aScriptLevel, em, leftSpace, rightSpace);
     // stretch the char to the appropriate height if it is not big enough.
     nsBoundingMetrics charSize;
     nsresult res = aMathMLChar->Stretch(aPresContext, aRenderingContext,
                                         NS_STRETCH_DIRECTION_VERTICAL,
                                         aContainerSize, charSize,
                                         NS_STRETCH_NORMAL, aRTL);
     if (NS_STRETCH_DIRECTION_UNSUPPORTED != aMathMLChar->GetStretchDirection()) {
       // has changed... so center the char around the axis
       nscoord height = charSize.ascent + charSize.descent;
       charSize.ascent = height/2 + axisHeight;
       charSize.descent = height - charSize.ascent;
     }
     else {
       // either it hasn't changed or stretching the char failed (i.e.,
       // GetBoundingMetrics failed)
       leading = 0;
       if (NS_FAILED(res)) {
         nsAutoString data;
         aMathMLChar->GetData(data);
         nsBoundingMetrics metrics =
           aRenderingContext.GetBoundingMetrics(data.get(), data.Length());
         charSize.ascent = metrics.ascent;
         charSize.descent = metrics.descent;
         charSize.width = metrics.width;
         // Set this as the bounding metrics of the MathMLChar to leave
         // the necessary room to paint the char.
         aMathMLChar->SetBoundingMetrics(charSize);
       }
     }
     if (aAscent < charSize.ascent + leading)
       aAscent = charSize.ascent + leading;
     if (aDescent < charSize.descent + leading)
       aDescent = charSize.descent + leading;
     // account the spacing
     charSize.width += leftSpace + rightSpace;
     // x-origin is used to store lspace ...
     // y-origin is used to stored the ascent ...
     aMathMLChar->SetRect(nsRect(leftSpace,
                                 charSize.ascent, charSize.width,
                                 charSize.ascent + charSize.descent));
   }
   return NS_OK;
 }
 /*static*/ void
 nsMathMLmfencedFrame::PlaceChar(nsMathMLChar*      aMathMLChar,
                                 nscoord            aDesiredAscent,
                                 nsBoundingMetrics& bm,
                                 nscoord&           dx)
 {
   aMathMLChar->GetBoundingMetrics(bm);
   // the char's x-origin was used to store lspace ...
   // the char's y-origin was used to store the ascent ...
   // the char's width was used to store the advance with (with spacing) ...
   nsRect rect;
   aMathMLChar->GetRect(rect);
   nscoord dy = aDesiredAscent - rect.y;
   if (aMathMLChar->GetStretchDirection() != NS_STRETCH_DIRECTION_UNSUPPORTED) {
     // the stretchy char will be centered around the axis
     // so we adjust the returned bounding metrics accordingly
     bm.descent = (bm.ascent + bm.descent) - rect.y;
     bm.ascent = rect.y;
   }
   aMathMLChar->SetRect(nsRect(dx + rect.x, dy, bm.width, rect.height));
   bm.leftBearing += rect.x;
   bm.rightBearing += rect.x;
   // return rect.width since it includes lspace and rspace
   bm.width = rect.width;
   dx += rect.width;
 }
 static nscoord
 GetMaxCharWidth(nsPresContext*       aPresContext,
                 nsRenderingContext* aRenderingContext,
                 nsMathMLChar*        aMathMLChar,
                 nsOperatorFlags      aForm,
                 int32_t              aScriptLevel,
                 nscoord              em)
 {
   nscoord width = aMathMLChar->GetMaxWidth(aPresContext, *aRenderingContext);
   if (0 < aMathMLChar->Length()) {
     nscoord leftSpace;
     nscoord rightSpace;
     GetCharSpacing(aMathMLChar, aForm, aScriptLevel, em, leftSpace, rightSpace);
     width += leftSpace + rightSpace;
   }
   return width;
 }
 /* virtual */ void
 nsMathMLmfencedFrame::GetIntrinsicWidthMetrics(nsRenderingContext* aRenderingContext, nsHTMLReflowMetrics& aDesiredSize)
 {
   nscoord width = 0;
   nsPresContext* presContext = PresContext();
   const nsStyleFont* font = StyleFont();
   nsRefPtr<nsFontMetrics> fm;
   nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
   nscoord em;
   GetEmHeight(fm, em);
   if (mOpenChar) {
     width +=
       GetMaxCharWidth(presContext, aRenderingContext, mOpenChar,
                       NS_MATHML_OPERATOR_FORM_PREFIX, font->mScriptLevel, em);
   }
   int32_t i = 0;
   nsIFrame* childFrame = GetFirstPrincipalChild();
   while (childFrame) {
     // XXX This includes margin while Reflow currently doesn't consider
     // margin, so we may end up with too much space, but, with stretchy
     // characters, this is an approximation anyway.
     width += nsLayoutUtils::IntrinsicForContainer(aRenderingContext, childFrame,
                                                   nsLayoutUtils::PREF_WIDTH);
     if (i < mSeparatorsCount) {
       width +=
         GetMaxCharWidth(presContext, aRenderingContext, &mSeparatorsChar[i],
                         NS_MATHML_OPERATOR_FORM_INFIX, font->mScriptLevel, em);
     }
     i++;
     childFrame = childFrame->GetNextSibling();
   }
   if (mCloseChar) {
     width +=
       GetMaxCharWidth(presContext, aRenderingContext, mCloseChar,
                       NS_MATHML_OPERATOR_FORM_POSTFIX, font->mScriptLevel, em);
   }
   aDesiredSize.Width() = width;
   aDesiredSize.mBoundingMetrics.width = width;
   aDesiredSize.mBoundingMetrics.leftBearing = 0;
   aDesiredSize.mBoundingMetrics.rightBearing = width;
 }
 nscoord
 nsMathMLmfencedFrame::FixInterFrameSpacing(nsHTMLReflowMetrics& aDesiredSize)
 {
   nscoord gap = nsMathMLContainerFrame::FixInterFrameSpacing(aDesiredSize);
   if (!gap) return 0;
   nsRect rect;
   if (mOpenChar) {
     mOpenChar->GetRect(rect);
     rect.MoveBy(gap, 0);
     mOpenChar->SetRect(rect);
   }
   if (mCloseChar) {
     mCloseChar->GetRect(rect);
     rect.MoveBy(gap, 0);
     mCloseChar->SetRect(rect);
   }
   for (int32_t i = 0; i < mSeparatorsCount; i++) {
     mSeparatorsChar[i].GetRect(rect);
     rect.MoveBy(gap, 0);
     mSeparatorsChar[i].SetRect(rect);
   }
   return gap;
 }
 // ----------------------
 // the Style System will use these to pass the proper style context to our MathMLChar
 nsStyleContext*
 nsMathMLmfencedFrame::GetAdditionalStyleContext(int32_t aIndex) const
 {
   int32_t openIndex = -1;
   int32_t closeIndex = -1;
   int32_t lastIndex = mSeparatorsCount-1;
   if (mOpenChar) {
     lastIndex++;
     openIndex = lastIndex;
   }
   if (mCloseChar) {
     lastIndex++;
     closeIndex = lastIndex;
   }
   if (aIndex < 0 || aIndex > lastIndex) {
     return nullptr;
   }
   if (aIndex < mSeparatorsCount) {
     return mSeparatorsChar[aIndex].GetStyleContext();
   }
   else if (aIndex == openIndex) {
     return mOpenChar->GetStyleContext();
   }
   else if (aIndex == closeIndex) {
     return mCloseChar->GetStyleContext();
   }
   return nullptr;
 }
 void
 nsMathMLmfencedFrame::SetAdditionalStyleContext(int32_t          aIndex,
                                                 nsStyleContext*  aStyleContext)
 {
   int32_t openIndex = -1;
   int32_t closeIndex = -1;
   int32_t lastIndex = mSeparatorsCount-1;
   if (mOpenChar) {
     lastIndex++;
     openIndex = lastIndex;
   }
   if (mCloseChar) {
     lastIndex++;
     closeIndex = lastIndex;
   }
   if (aIndex < 0 || aIndex > lastIndex) {
     return;
   }
   if (aIndex < mSeparatorsCount) {
     mSeparatorsChar[aIndex].SetStyleContext(aStyleContext);
   }
   else if (aIndex == openIndex) {
     mOpenChar->SetStyleContext(aStyleContext);
   }
   else if (aIndex == closeIndex) {
     mCloseChar->SetStyleContext(aStyleContext);
   }
 }

The Tor Browser / annotate

layout/mathml/nsMathMLmfencedFrame.cpp@ac0c01689b40 (annotated)

layout/mathml/nsMathMLmfencedFrame.cpp