void
nsMathMLmpaddedFrame::UpdateValue(int32_t                  aSign,
                                  int32_t                  aPseudoUnit,
                                  const nsCSSValue&        aCSSValue,
                                  const nsHTMLReflowMetrics& aDesiredSize,
                                  nscoord&                 aValueToUpdate) const
{
  nsCSSUnit unit = aCSSValue.GetUnit();
  if (NS_MATHML_SIGN_INVALID != aSign && eCSSUnit_Null != unit) {
    nscoord scaler = 0, amount = 0;

    if (eCSSUnit_Percent == unit || eCSSUnit_Number == unit) {
      switch(aPseudoUnit) {
        case NS_MATHML_PSEUDO_UNIT_WIDTH:
             scaler = aDesiredSize.Width();
             break;

        case NS_MATHML_PSEUDO_UNIT_HEIGHT:
             scaler = aDesiredSize.TopAscent();
             break;

        case NS_MATHML_PSEUDO_UNIT_DEPTH:
             scaler = aDesiredSize.Height() - aDesiredSize.TopAscent();
             break;

        default:
          // if we ever reach here, it would mean something is wrong 
          // somewhere with the setup and/or the caller
          NS_ERROR("Unexpected Pseudo Unit");
          return;
      }
    }

    if (eCSSUnit_Number == unit)
      amount = NSToCoordRound(float(scaler) * aCSSValue.GetFloatValue());
    else if (eCSSUnit_Percent == unit)
      amount = NSToCoordRound(float(scaler) * aCSSValue.GetPercentValue());
    else
      amount = CalcLength(PresContext(), mStyleContext, aCSSValue);

    if (NS_MATHML_SIGN_PLUS == aSign)
      aValueToUpdate += amount;
    else if (NS_MATHML_SIGN_MINUS == aSign)
      aValueToUpdate -= amount;
    else
      aValueToUpdate  = amount;
  }
}
// For token elements, mBoundingMetrics is computed at the ReflowToken
// pass, it is not computed here because our children may be text frames
// that do not implement the GetBoundingMetrics() interface.
/* virtual */ nsresult
nsMathMLTokenFrame::Place(nsRenderingContext& aRenderingContext,
                          bool                 aPlaceOrigin,
                          nsHTMLReflowMetrics& aDesiredSize)
{
  mBoundingMetrics = nsBoundingMetrics();
  for (nsIFrame* childFrame = GetFirstPrincipalChild(); childFrame;
       childFrame = childFrame->GetNextSibling()) {
    nsHTMLReflowMetrics childSize(aDesiredSize.GetWritingMode());
    GetReflowAndBoundingMetricsFor(childFrame, childSize,
                                   childSize.mBoundingMetrics, nullptr);
    // compute and cache the bounding metrics
    mBoundingMetrics += childSize.mBoundingMetrics;
  }

  nsRefPtr<nsFontMetrics> fm;
  nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
  nscoord ascent = fm->MaxAscent();
  nscoord descent = fm->MaxDescent();

  aDesiredSize.mBoundingMetrics = mBoundingMetrics;
  aDesiredSize.Width() = mBoundingMetrics.width;
  aDesiredSize.SetTopAscent(std::max(mBoundingMetrics.ascent, ascent));
  aDesiredSize.Height() = aDesiredSize.TopAscent() +
                        std::max(mBoundingMetrics.descent, descent);

  if (aPlaceOrigin) {
    nscoord dy, dx = 0;
    for (nsIFrame* childFrame = GetFirstPrincipalChild(); childFrame;
         childFrame = childFrame->GetNextSibling()) {
      nsHTMLReflowMetrics childSize(aDesiredSize.GetWritingMode());
      GetReflowAndBoundingMetricsFor(childFrame, childSize,
                                     childSize.mBoundingMetrics);

      // place and size the child; (dx,0) makes the caret happy - bug 188146
      dy = childSize.Height() == 0 ? 0 : aDesiredSize.TopAscent() - childSize.TopAscent();
      FinishReflowChild(childFrame, PresContext(), childSize, nullptr, dx, dy, 0);
      dx += childSize.Width();
    }
  }

  SetReference(nsPoint(0, aDesiredSize.TopAscent()));

  return NS_OK;
}
void
nsMathMLmspaceFrame::Reflow(nsPresContext*          aPresContext,
                            nsHTMLReflowMetrics&     aDesiredSize,
                            const nsHTMLReflowState& aReflowState,
                            nsReflowStatus&          aStatus)
{
  ProcessAttributes(aPresContext);

  mBoundingMetrics = nsBoundingMetrics();
  mBoundingMetrics.width = mWidth;
  mBoundingMetrics.ascent = mHeight;
  mBoundingMetrics.descent = mDepth;
  mBoundingMetrics.leftBearing = 0;
  mBoundingMetrics.rightBearing = mBoundingMetrics.width;

  aDesiredSize.SetTopAscent(mHeight);
  aDesiredSize.Width() = std::max(0, mBoundingMetrics.width);
  aDesiredSize.Height() = aDesiredSize.TopAscent() + mDepth;
  // Also return our bounding metrics
  aDesiredSize.mBoundingMetrics = mBoundingMetrics;

  aStatus = NS_FRAME_COMPLETE;
  NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
}
nsresult
nsFirstLetterFrame::Reflow(nsPresContext*          aPresContext,
                           nsHTMLReflowMetrics&     aMetrics,
                           const nsHTMLReflowState& aReflowState,
                           nsReflowStatus&          aReflowStatus)
{
  DO_GLOBAL_REFLOW_COUNT("nsFirstLetterFrame");
  DISPLAY_REFLOW(aPresContext, this, aReflowState, aMetrics, aReflowStatus);
  nsresult rv = NS_OK;

  // Grab overflow list
  DrainOverflowFrames(aPresContext);

  nsIFrame* kid = mFrames.FirstChild();

  // Setup reflow state for our child
  nsSize availSize(aReflowState.AvailableWidth(), aReflowState.AvailableHeight());
  const nsMargin& bp = aReflowState.ComputedPhysicalBorderPadding();
  nscoord lr = bp.left + bp.right;
  nscoord tb = bp.top + bp.bottom;
  NS_ASSERTION(availSize.width != NS_UNCONSTRAINEDSIZE,
               "should no longer use unconstrained widths");
  availSize.width -= lr;
  if (NS_UNCONSTRAINEDSIZE != availSize.height) {
    availSize.height -= tb;
  }

  // Reflow the child
  if (!aReflowState.mLineLayout) {
    // When there is no lineLayout provided, we provide our own. The
    // only time that the first-letter-frame is not reflowing in a
    // line context is when its floating.
    nsHTMLReflowState rs(aPresContext, aReflowState, kid, availSize);
    nsLineLayout ll(aPresContext, nullptr, &aReflowState, nullptr);

    ll.BeginLineReflow(bp.left, bp.top, availSize.width, NS_UNCONSTRAINEDSIZE,
                       false, true,
                       ll.LineContainerFrame()->GetWritingMode(kid),
                       aReflowState.AvailableWidth());
    rs.mLineLayout = &ll;
    ll.SetInFirstLetter(true);
    ll.SetFirstLetterStyleOK(true);

    kid->WillReflow(aPresContext);
    kid->Reflow(aPresContext, aMetrics, rs, aReflowStatus);

    ll.EndLineReflow();
    ll.SetInFirstLetter(false);

    // In the floating first-letter case, we need to set this ourselves;
    // nsLineLayout::BeginSpan will set it in the other case
    mBaseline = aMetrics.TopAscent();
  }
  else {
    // Pretend we are a span and reflow the child frame
    nsLineLayout* ll = aReflowState.mLineLayout;
    bool          pushedFrame;

    ll->SetInFirstLetter(
      mStyleContext->GetPseudo() == nsCSSPseudoElements::firstLetter);
    ll->BeginSpan(this, &aReflowState, bp.left, availSize.width, &mBaseline);
    ll->ReflowFrame(kid, aReflowStatus, &aMetrics, pushedFrame);
    ll->EndSpan(this);
    ll->SetInFirstLetter(false);
  }

  // Place and size the child and update the output metrics
  kid->SetRect(nsRect(bp.left, bp.top, aMetrics.Width(), aMetrics.Height()));
  kid->FinishAndStoreOverflow(&aMetrics);
  kid->DidReflow(aPresContext, nullptr, nsDidReflowStatus::FINISHED);

  aMetrics.Width() += lr;
  aMetrics.Height() += tb;
  aMetrics.SetTopAscent(aMetrics.TopAscent() + bp.top);

  // Ensure that the overflow rect contains the child textframe's overflow rect.
  // Note that if this is floating, the overline/underline drawable area is in
  // the overflow rect of the child textframe.
  aMetrics.UnionOverflowAreasWithDesiredBounds();
  ConsiderChildOverflow(aMetrics.mOverflowAreas, kid);

  if (!NS_INLINE_IS_BREAK_BEFORE(aReflowStatus)) {
    // Create a continuation or remove existing continuations based on
    // the reflow completion status.
    if (NS_FRAME_IS_COMPLETE(aReflowStatus)) {
      if (aReflowState.mLineLayout) {
        aReflowState.mLineLayout->SetFirstLetterStyleOK(false);
      }
      nsIFrame* kidNextInFlow = kid->GetNextInFlow();
      if (kidNextInFlow) {
        // Remove all of the childs next-in-flows
        static_cast<nsContainerFrame*>(kidNextInFlow->GetParent())
          ->DeleteNextInFlowChild(kidNextInFlow, true);
      }
    }
    else {
      // Create a continuation for the child frame if it doesn't already
      // have one.
      if (!IsFloating()) {
        nsIFrame* nextInFlow;
        rv = CreateNextInFlow(kid, nextInFlow);
        if (NS_FAILED(rv)) {
          return rv;
        }
    
        // And then push it to our overflow list
        const nsFrameList& overflow = mFrames.RemoveFramesAfter(kid);
        if (overflow.NotEmpty()) {
          SetOverflowFrames(overflow);
        }
      } else if (!kid->GetNextInFlow()) {
        // For floating first letter frames (if a continuation wasn't already
        // created for us) we need to put the continuation with the rest of the
        // text that the first letter frame was made out of.
        nsIFrame* continuation;
        rv = CreateContinuationForFloatingParent(aPresContext, kid,
                                                 &continuation, true);
      }
    }
  }

  FinishAndStoreOverflow(&aMetrics);

  NS_FRAME_SET_TRUNCATION(aReflowStatus, aReflowState, aMetrics);
  return rv;
}
Exemple #5
0
void
nsInlineFrame::ReflowFrames(nsPresContext* aPresContext,
                            const nsHTMLReflowState& aReflowState,
                            InlineReflowState& irs,
                            nsHTMLReflowMetrics& aMetrics,
                            nsReflowStatus& aStatus)
{
  aStatus = NS_FRAME_COMPLETE;

  nsLineLayout* lineLayout = aReflowState.mLineLayout;
  bool inFirstLine = aReflowState.mLineLayout->GetInFirstLine();
  RestyleManager* restyleManager = aPresContext->RestyleManager();
  WritingMode frameWM = aReflowState.GetWritingMode();
  WritingMode lineWM = aReflowState.mLineLayout->mRootSpan->mWritingMode;
  LogicalMargin framePadding = aReflowState.ComputedLogicalBorderPadding();
  nscoord startEdge = 0;
  const bool boxDecorationBreakClone =
    MOZ_UNLIKELY(StyleBorder()->mBoxDecorationBreak ==
                   NS_STYLE_BOX_DECORATION_BREAK_CLONE);
  // Don't offset by our start borderpadding if we have a prev continuation or
  // if we're in a part of an {ib} split other than the first one. For
  // box-decoration-break:clone we always offset our start since all
  // continuations have border/padding.
  if ((!GetPrevContinuation() && !FrameIsNonFirstInIBSplit()) ||
      boxDecorationBreakClone) {
    startEdge = framePadding.IStart(frameWM);
  }
  nscoord availableISize = aReflowState.AvailableISize();
  NS_ASSERTION(availableISize != NS_UNCONSTRAINEDSIZE,
               "should no longer use available widths");
  // Subtract off inline axis border+padding from availableISize
  availableISize -= startEdge;
  availableISize -= framePadding.IEnd(frameWM);
  lineLayout->BeginSpan(this, &aReflowState, startEdge,
                        startEdge + availableISize, &mBaseline);

  // First reflow our principal children.
  nsIFrame* frame = mFrames.FirstChild();
  bool done = false;
  while (frame) {
    // Check if we should lazily set the child frame's parent pointer.
    if (irs.mSetParentPointer) {
      bool havePrevBlock =
        irs.mLineContainer && irs.mLineContainer->GetPrevContinuation();
      nsIFrame* child = frame;
      do {
        // If our block is the first in flow, then any floats under the pulled
        // frame must already belong to our block.
        if (havePrevBlock) {
          // This has to happen before we update frame's parent; we need to
          // know frame's ancestry under its old block.
          // The blockChildren.ContainsFrame check performed by
          // ReparentFloatsForInlineChild here may be slow, but we can't
          // easily avoid it because we don't know where 'frame' originally
          // came from. If we really really have to optimize this we could
          // cache whether frame->GetParent() is under its containing blocks
          // overflowList or not.
          ReparentFloatsForInlineChild(irs.mLineContainer, child, false);
        }
        child->SetParent(this);
        if (inFirstLine) {
          restyleManager->ReparentStyleContext(child);
          nsLayoutUtils::MarkDescendantsDirty(child);
        }
        // We also need to do the same for |frame|'s next-in-flows that are in
        // the sibling list. Otherwise, if we reflow |frame| and it's complete
        // we'll crash when trying to delete its next-in-flow.
        // This scenario doesn't happen often, but it can happen.
        nsIFrame* nextSibling = child->GetNextSibling();
        child = child->GetNextInFlow();
        if (MOZ_UNLIKELY(child)) {
          while (child != nextSibling && nextSibling) {
            nextSibling = nextSibling->GetNextSibling();
          }
          if (!nextSibling) {
            child = nullptr;
          }
        }
        MOZ_ASSERT(!child || mFrames.ContainsFrame(child));
      } while (child);

      // Fix the parent pointer for ::first-letter child frame next-in-flows,
      // so nsFirstLetterFrame::Reflow can destroy them safely (bug 401042).
      nsIFrame* realFrame = nsPlaceholderFrame::GetRealFrameFor(frame);
      if (realFrame->GetType() == nsGkAtoms::letterFrame) {
        nsIFrame* child = realFrame->GetFirstPrincipalChild();
        if (child) {
          NS_ASSERTION(child->GetType() == nsGkAtoms::textFrame,
                       "unexpected frame type");
          nsIFrame* nextInFlow = child->GetNextInFlow();
          for ( ; nextInFlow; nextInFlow = nextInFlow->GetNextInFlow()) {
            NS_ASSERTION(nextInFlow->GetType() == nsGkAtoms::textFrame,
                         "unexpected frame type");
            if (mFrames.ContainsFrame(nextInFlow)) {
              nextInFlow->SetParent(this);
              if (inFirstLine) {
                restyleManager->ReparentStyleContext(nextInFlow);
                nsLayoutUtils::MarkDescendantsDirty(nextInFlow);
              }
            }
            else {
#ifdef DEBUG              
              // Once we find a next-in-flow that isn't ours none of the
              // remaining next-in-flows should be either.
              for ( ; nextInFlow; nextInFlow = nextInFlow->GetNextInFlow()) {
                NS_ASSERTION(!mFrames.ContainsFrame(nextInFlow),
                             "unexpected letter frame flow");
              }
#endif
              break;
            }
          }
        }
      }
    }
    MOZ_ASSERT(frame->GetParent() == this);

    if (!done) {
      bool reflowingFirstLetter = lineLayout->GetFirstLetterStyleOK();
      ReflowInlineFrame(aPresContext, aReflowState, irs, frame, aStatus);
      done = NS_INLINE_IS_BREAK(aStatus) || 
             (!reflowingFirstLetter && NS_FRAME_IS_NOT_COMPLETE(aStatus));
      if (done) {
        if (!irs.mSetParentPointer) {
          break;
        }
        // Keep reparenting the remaining siblings, but don't reflow them.
        nsFrameList* pushedFrames = GetOverflowFrames();
        if (pushedFrames && pushedFrames->FirstChild() == frame) {
          // Don't bother if |frame| was pushed to our overflow list.
          break;
        }
      } else {
        irs.mPrevFrame = frame;
      }
    }
    frame = frame->GetNextSibling();
  }

  // Attempt to pull frames from our next-in-flow until we can't
  if (!done && GetNextInFlow()) {
    while (true) {
      bool reflowingFirstLetter = lineLayout->GetFirstLetterStyleOK();
      bool isComplete;
      if (!frame) { // Could be non-null if we pulled a first-letter frame and
                    // it created a continuation, since we don't push those.
        frame = PullOneFrame(aPresContext, irs, &isComplete);
      }
#ifdef NOISY_PUSHING
      printf("%p pulled up %p\n", this, frame);
#endif
      if (nullptr == frame) {
        if (!isComplete) {
          aStatus = NS_FRAME_NOT_COMPLETE;
        }
        break;
      }
      ReflowInlineFrame(aPresContext, aReflowState, irs, frame, aStatus);
      if (NS_INLINE_IS_BREAK(aStatus) || 
          (!reflowingFirstLetter && NS_FRAME_IS_NOT_COMPLETE(aStatus))) {
        break;
      }
      irs.mPrevFrame = frame;
      frame = frame->GetNextSibling();
    }
  }

  NS_ASSERTION(!NS_FRAME_IS_COMPLETE(aStatus) || !GetOverflowFrames(),
               "We can't be complete AND have overflow frames!");

  // If after reflowing our children they take up no area then make
  // sure that we don't either.
  //
  // Note: CSS demands that empty inline elements still affect the
  // line-height calculations. However, continuations of an inline
  // that are empty we force to empty so that things like collapsed
  // whitespace in an inline element don't affect the line-height.
  aMetrics.ISize(lineWM) = lineLayout->EndSpan(this);

  // Compute final width.

  // XXX Note that that the padding start and end are in the frame's
  //     writing mode, but the metrics' inline-size is in the line's
  //     writing mode. This makes sense if the line and frame are both
  //     vertical or both horizontal, but what should happen with
  //     orthogonal inlines?

  // Make sure to not include our start border and padding if we have a prev
  // continuation or if we're in a part of an {ib} split other than the first
  // one.  For box-decoration-break:clone we always include our start border
  // and padding since all continuations have them.
  if ((!GetPrevContinuation() && !FrameIsNonFirstInIBSplit()) ||
      boxDecorationBreakClone) {
    aMetrics.ISize(lineWM) += framePadding.IStart(frameWM);
  }

  /*
   * We want to only apply the end border and padding if we're the last
   * continuation and either not in an {ib} split or the last part of it.  To
   * be the last continuation we have to be complete (so that we won't get a
   * next-in-flow) and have no non-fluid continuations on our continuation
   * chain.  For box-decoration-break:clone we always apply the end border and
   * padding since all continuations have them.
   */
  if ((NS_FRAME_IS_COMPLETE(aStatus) &&
       !LastInFlow()->GetNextContinuation() &&
       !FrameIsNonLastInIBSplit()) ||
      boxDecorationBreakClone) {
    aMetrics.ISize(lineWM) += framePadding.IEnd(frameWM);
  }

  nsLayoutUtils::SetBSizeFromFontMetrics(this, aMetrics, aReflowState,
                                         framePadding, lineWM, frameWM);

  // For now our overflow area is zero. The real value will be
  // computed in |nsLineLayout::RelativePositionFrames|.
  aMetrics.mOverflowAreas.Clear();

#ifdef NOISY_FINAL_SIZE
  ListTag(stdout);
  printf(": metrics=%d,%d ascent=%d\n",
         aMetrics.Width(), aMetrics.Height(), aMetrics.TopAscent());
#endif
}
/* virtual */ nsresult
nsMathMLmpaddedFrame::Place(nsRenderingContext& aRenderingContext,
                            bool                 aPlaceOrigin,
                            nsHTMLReflowMetrics& aDesiredSize)
{
  nsresult rv =
    nsMathMLContainerFrame::Place(aRenderingContext, false, aDesiredSize);
  if (NS_MATHML_HAS_ERROR(mPresentationData.flags) || NS_FAILED(rv)) {
    DidReflowChildren(GetFirstPrincipalChild());
    return rv;
  }

  nscoord height = aDesiredSize.TopAscent();
  nscoord depth  = aDesiredSize.Height() - aDesiredSize.TopAscent();
  // The REC says:
  //
  // "The lspace attribute ('leading' space) specifies the horizontal location
  // of the positioning point of the child content with respect to the
  // positioning point of the mpadded element. By default they coincide, and
  // therefore absolute values for lspace have the same effect as relative
  // values."
  //
  // "MathML renderers should ensure that, except for the effects of the
  // attributes, the relative spacing between the contents of the mpadded
  // element and surrounding MathML elements would not be modified by replacing
  // an mpadded element with an mrow element with the same content, even if
  // linebreaking occurs within the mpadded element."
  //
  // (http://www.w3.org/TR/MathML/chapter3.html#presm.mpadded)
  // 
  // "In those discussions, the terms leading and trailing are used to specify
  // a side of an object when which side to use depends on the directionality;
  // ie. leading means left in LTR but right in RTL."
  // (http://www.w3.org/TR/MathML/chapter3.html#presm.bidi.math)
  nscoord lspace = 0;
  // In MathML3, "width" will be the bounding box width and "advancewidth" will
  // refer "to the horizontal distance between the positioning point of the
  // mpadded and the positioning point for the following content".  MathML2
  // doesn't make the distinction.
  nscoord width  = aDesiredSize.Width();
  nscoord voffset = 0;

  int32_t pseudoUnit;
  nscoord initialWidth = width;

  // update width
  pseudoUnit = (mWidthPseudoUnit == NS_MATHML_PSEUDO_UNIT_ITSELF)
             ? NS_MATHML_PSEUDO_UNIT_WIDTH : mWidthPseudoUnit;
  UpdateValue(mWidthSign, pseudoUnit, mWidth,
              aDesiredSize, width);
  width = std::max(0, width);

  // update "height" (this is the ascent in the terminology of the REC)
  pseudoUnit = (mHeightPseudoUnit == NS_MATHML_PSEUDO_UNIT_ITSELF)
             ? NS_MATHML_PSEUDO_UNIT_HEIGHT : mHeightPseudoUnit;
  UpdateValue(mHeightSign, pseudoUnit, mHeight,
              aDesiredSize, height);
  height = std::max(0, height);

  // update "depth" (this is the descent in the terminology of the REC)
  pseudoUnit = (mDepthPseudoUnit == NS_MATHML_PSEUDO_UNIT_ITSELF)
             ? NS_MATHML_PSEUDO_UNIT_DEPTH : mDepthPseudoUnit;
  UpdateValue(mDepthSign, pseudoUnit, mDepth,
              aDesiredSize, depth);
  depth = std::max(0, depth);

  // update lspace
  if (mLeadingSpacePseudoUnit != NS_MATHML_PSEUDO_UNIT_ITSELF) {
    pseudoUnit = mLeadingSpacePseudoUnit;
    UpdateValue(mLeadingSpaceSign, pseudoUnit, mLeadingSpace,
                aDesiredSize, lspace);
  }

  // update voffset
  if (mVerticalOffsetPseudoUnit != NS_MATHML_PSEUDO_UNIT_ITSELF) {
    pseudoUnit = mVerticalOffsetPseudoUnit;
    UpdateValue(mVerticalOffsetSign, pseudoUnit, mVerticalOffset,
                aDesiredSize, voffset);
  }
  // do the padding now that we have everything
  // The idea here is to maintain the invariant that <mpadded>...</mpadded> (i.e.,
  // with no attributes) looks the same as <mrow>...</mrow>. But when there are
  // attributes, tweak our metrics and move children to achieve the desired visual
  // effects.

  if ((StyleVisibility()->mDirection ?
       mWidthSign : mLeadingSpaceSign) != NS_MATHML_SIGN_INVALID) {
    // there was padding on the left. dismiss the left italic correction now
    // (so that our parent won't correct us)
    mBoundingMetrics.leftBearing = 0;
  }

  if ((StyleVisibility()->mDirection ?
       mLeadingSpaceSign : mWidthSign) != NS_MATHML_SIGN_INVALID) {
    // there was padding on the right. dismiss the right italic correction now
    // (so that our parent won't correct us)
    mBoundingMetrics.width = width;
    mBoundingMetrics.rightBearing = mBoundingMetrics.width;
  }

  nscoord dx = (StyleVisibility()->mDirection ?
                width - initialWidth - lspace : lspace);
    
  aDesiredSize.SetTopAscent(height);
  aDesiredSize.Width() = mBoundingMetrics.width;
  aDesiredSize.Height() = depth + aDesiredSize.TopAscent();
  mBoundingMetrics.ascent = height;
  mBoundingMetrics.descent = depth;
  aDesiredSize.mBoundingMetrics = mBoundingMetrics;

  mReference.x = 0;
  mReference.y = aDesiredSize.TopAscent();

  if (aPlaceOrigin) {
    // Finish reflowing child frames, positioning their origins.
    PositionRowChildFrames(dx, aDesiredSize.TopAscent() - voffset);
  }

  return NS_OK;
}
/* virtual */ nsresult
nsMathMLmencloseFrame::PlaceInternal(nsRenderingContext& aRenderingContext,
                                     bool                 aPlaceOrigin,
                                     nsHTMLReflowMetrics& aDesiredSize,
                                     bool                 aWidthOnly)
{
  ///////////////
  // Measure the size of our content using the base class to format like an
  // inferred mrow.
  nsHTMLReflowMetrics baseSize(aDesiredSize.GetWritingMode());
  nsresult rv =
    nsMathMLContainerFrame::Place(aRenderingContext, false, baseSize);

  if (NS_MATHML_HAS_ERROR(mPresentationData.flags) || NS_FAILED(rv)) {
      DidReflowChildren(GetFirstPrincipalChild());
      return rv;
    }

  nsBoundingMetrics bmBase = baseSize.mBoundingMetrics;
  nscoord dx_left = 0, dx_right = 0;
  nsBoundingMetrics bmLongdivChar, bmRadicalChar;
  nscoord radicalAscent = 0, radicalDescent = 0;
  nscoord longdivAscent = 0, longdivDescent = 0;
  nscoord psi = 0;

  ///////////////
  // Thickness of bars and font metrics
  nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);

  nscoord mEmHeight;
  nsRefPtr<nsFontMetrics> fm;
  nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
  aRenderingContext.SetFont(fm);
  GetRuleThickness(aRenderingContext, fm, mRuleThickness);
  GetEmHeight(fm, mEmHeight);

  char16_t one = '1';
  nsBoundingMetrics bmOne = aRenderingContext.GetBoundingMetrics(&one, 1);

  ///////////////
  // General rules: the menclose element takes the size of the enclosed content.
  // We add a padding when needed.

  // determine padding & psi
  nscoord padding = 3 * mRuleThickness;
  nscoord delta = padding % onePixel;
  if (delta)
    padding += onePixel - delta; // round up

  if (IsToDraw(NOTATION_LONGDIV) || IsToDraw(NOTATION_RADICAL)) {
      nscoord phi;
      // Rule 11, App. G, TeXbook
      // psi = clearance between rule and content
      if (NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags))
        phi = fm->XHeight();
      else
        phi = mRuleThickness;
      psi = mRuleThickness + phi / 4;

      delta = psi % onePixel;
      if (delta)
        psi += onePixel - delta; // round up
    }

  if (mRuleThickness < onePixel)
    mRuleThickness = onePixel;
 
  // Set horizontal parameters
  if (IsToDraw(NOTATION_ROUNDEDBOX) ||
      IsToDraw(NOTATION_TOP) ||
      IsToDraw(NOTATION_LEFT) ||
      IsToDraw(NOTATION_BOTTOM) ||
      IsToDraw(NOTATION_CIRCLE))
    dx_left = padding;

  if (IsToDraw(NOTATION_ROUNDEDBOX) ||
      IsToDraw(NOTATION_TOP) ||
      IsToDraw(NOTATION_RIGHT) ||
      IsToDraw(NOTATION_BOTTOM) ||
      IsToDraw(NOTATION_CIRCLE))
    dx_right = padding;

  // Set vertical parameters
  if (IsToDraw(NOTATION_RIGHT) ||
      IsToDraw(NOTATION_LEFT) ||
      IsToDraw(NOTATION_UPDIAGONALSTRIKE) ||
      IsToDraw(NOTATION_UPDIAGONALARROW) ||
      IsToDraw(NOTATION_DOWNDIAGONALSTRIKE) ||
      IsToDraw(NOTATION_VERTICALSTRIKE) ||
      IsToDraw(NOTATION_CIRCLE) ||
      IsToDraw(NOTATION_ROUNDEDBOX) ||
      IsToDraw(NOTATION_RADICAL) ||
      IsToDraw(NOTATION_LONGDIV)) {
      // set a minimal value for the base height
      bmBase.ascent = std::max(bmOne.ascent, bmBase.ascent);
      bmBase.descent = std::max(0, bmBase.descent);
  }

  mBoundingMetrics.ascent = bmBase.ascent;
  mBoundingMetrics.descent = bmBase.descent;
    
  if (IsToDraw(NOTATION_ROUNDEDBOX) ||
      IsToDraw(NOTATION_TOP) ||
      IsToDraw(NOTATION_LEFT) ||
      IsToDraw(NOTATION_RIGHT) ||
      IsToDraw(NOTATION_CIRCLE))
    mBoundingMetrics.ascent += padding;
  
  if (IsToDraw(NOTATION_ROUNDEDBOX) ||
      IsToDraw(NOTATION_LEFT) ||
      IsToDraw(NOTATION_RIGHT) ||
      IsToDraw(NOTATION_BOTTOM) ||
      IsToDraw(NOTATION_CIRCLE))
    mBoundingMetrics.descent += padding;

  ///////////////
  // updiagonal arrow notation. We need enough space at the top right corner to
  // draw the arrow head.
  if (IsToDraw(NOTATION_UPDIAGONALARROW)) {
    // This is an estimate, see nsDisplayNotation::Paint for the exact head size
    nscoord arrowHeadSize = kArrowHeadSize * mRuleThickness;

    // We want that the arrow shaft strikes the menclose content and that the
    // arrow head does not overlap with that content. Hence we add some space
    // on the right. We don't add space on the top but only ensure that the
    // ascent is large enough.
    dx_right = std::max(dx_right, arrowHeadSize);
    mBoundingMetrics.ascent = std::max(mBoundingMetrics.ascent, arrowHeadSize);
  }

  ///////////////
  // circle notation: we don't want the ellipse to overlap the enclosed
  // content. Hence, we need to increase the size of the bounding box by a
  // factor of at least sqrt(2).
  if (IsToDraw(NOTATION_CIRCLE)) {
    double ratio = (sqrt(2.0) - 1.0) / 2.0;
    nscoord padding2;

    // Update horizontal parameters
    padding2 = ratio * bmBase.width;

    dx_left = std::max(dx_left, padding2);
    dx_right = std::max(dx_right, padding2);

    // Update vertical parameters
    padding2 = ratio * (bmBase.ascent + bmBase.descent);

    mBoundingMetrics.ascent = std::max(mBoundingMetrics.ascent,
                                     bmBase.ascent + padding2);
    mBoundingMetrics.descent = std::max(mBoundingMetrics.descent,
                                      bmBase.descent + padding2);
  }

  ///////////////
  // longdiv notation:
  if (IsToDraw(NOTATION_LONGDIV)) {
    if (aWidthOnly) {
        nscoord longdiv_width = mMathMLChar[mLongDivCharIndex].
          GetMaxWidth(PresContext(), aRenderingContext);

        // Update horizontal parameters
        dx_left = std::max(dx_left, longdiv_width);
    } else {
      // Stretch the parenthesis to the appropriate height if it is not
      // big enough.
      nsBoundingMetrics contSize = bmBase;
      contSize.ascent = mRuleThickness;
      contSize.descent = bmBase.ascent + bmBase.descent + psi;

      // height(longdiv) should be >= height(base) + psi + mRuleThickness
      mMathMLChar[mLongDivCharIndex].Stretch(PresContext(), aRenderingContext,
                                             NS_STRETCH_DIRECTION_VERTICAL,
                                             contSize, bmLongdivChar,
                                             NS_STRETCH_LARGER, false);
      mMathMLChar[mLongDivCharIndex].GetBoundingMetrics(bmLongdivChar);

      // Update horizontal parameters
      dx_left = std::max(dx_left, bmLongdivChar.width);

      // Update vertical parameters
      longdivAscent = bmBase.ascent + psi + mRuleThickness;
      longdivDescent = std::max(bmBase.descent,
                              (bmLongdivChar.ascent + bmLongdivChar.descent -
                               longdivAscent));

      mBoundingMetrics.ascent = std::max(mBoundingMetrics.ascent,
                                       longdivAscent);
      mBoundingMetrics.descent = std::max(mBoundingMetrics.descent,
                                        longdivDescent);
    }
  }

  ///////////////
  // radical notation:
  if (IsToDraw(NOTATION_RADICAL)) {
    nscoord *dx_leading = StyleVisibility()->mDirection ? &dx_right : &dx_left;
    
    if (aWidthOnly) {
      nscoord radical_width = mMathMLChar[mRadicalCharIndex].
        GetMaxWidth(PresContext(), aRenderingContext);
      
      // Update horizontal parameters
      *dx_leading = std::max(*dx_leading, radical_width);
    } else {
      // Stretch the radical symbol to the appropriate height if it is not
      // big enough.
      nsBoundingMetrics contSize = bmBase;
      contSize.ascent = mRuleThickness;
      contSize.descent = bmBase.ascent + bmBase.descent + psi;

      // height(radical) should be >= height(base) + psi + mRuleThickness
      mMathMLChar[mRadicalCharIndex].Stretch(PresContext(), aRenderingContext,
                                             NS_STRETCH_DIRECTION_VERTICAL,
                                             contSize, bmRadicalChar,
                                             NS_STRETCH_LARGER,
                                             StyleVisibility()->mDirection);
      mMathMLChar[mRadicalCharIndex].GetBoundingMetrics(bmRadicalChar);

      // Update horizontal parameters
      *dx_leading = std::max(*dx_leading, bmRadicalChar.width);

      // Update vertical parameters
      radicalAscent = bmBase.ascent + psi + mRuleThickness;
      radicalDescent = std::max(bmBase.descent,
                              (bmRadicalChar.ascent + bmRadicalChar.descent -
                               radicalAscent));

      mBoundingMetrics.ascent = std::max(mBoundingMetrics.ascent,
                                       radicalAscent);
      mBoundingMetrics.descent = std::max(mBoundingMetrics.descent,
                                        radicalDescent);
    }
  }

  ///////////////
  //
  if (IsToDraw(NOTATION_CIRCLE) ||
      IsToDraw(NOTATION_ROUNDEDBOX) ||
      (IsToDraw(NOTATION_LEFT) && IsToDraw(NOTATION_RIGHT))) {
    // center the menclose around the content (horizontally)
    dx_left = dx_right = std::max(dx_left, dx_right);
  }

  ///////////////
  // The maximum size is now computed: set the remaining parameters
  mBoundingMetrics.width = dx_left + bmBase.width + dx_right;

  mBoundingMetrics.leftBearing = std::min(0, dx_left + bmBase.leftBearing);
  mBoundingMetrics.rightBearing =
    std::max(mBoundingMetrics.width, dx_left + bmBase.rightBearing);
  
  aDesiredSize.Width() = mBoundingMetrics.width;

  aDesiredSize.SetTopAscent(std::max(mBoundingMetrics.ascent, baseSize.TopAscent()));
  aDesiredSize.Height() = aDesiredSize.TopAscent() +
    std::max(mBoundingMetrics.descent, baseSize.Height() - baseSize.TopAscent());

  if (IsToDraw(NOTATION_LONGDIV) || IsToDraw(NOTATION_RADICAL)) {
    // get the leading to be left at the top of the resulting frame
    // this seems more reliable than using fm->GetLeading() on suspicious
    // fonts
    nscoord leading = nscoord(0.2f * mEmHeight);
    nscoord desiredSizeAscent = aDesiredSize.TopAscent();
    nscoord desiredSizeDescent = aDesiredSize.Height() - aDesiredSize.TopAscent();
    
    if (IsToDraw(NOTATION_LONGDIV)) {
      desiredSizeAscent = std::max(desiredSizeAscent,
                                 longdivAscent + leading);
      desiredSizeDescent = std::max(desiredSizeDescent,
                                  longdivDescent + mRuleThickness);
    }
    
    if (IsToDraw(NOTATION_RADICAL)) {
      desiredSizeAscent = std::max(desiredSizeAscent,
                                 radicalAscent + leading);
      desiredSizeDescent = std::max(desiredSizeDescent,
                                  radicalDescent + mRuleThickness);
    }

    aDesiredSize.SetTopAscent(desiredSizeAscent);
    aDesiredSize.Height() = desiredSizeAscent + desiredSizeDescent;
  }
    
  if (IsToDraw(NOTATION_CIRCLE) ||
      IsToDraw(NOTATION_ROUNDEDBOX) ||
      (IsToDraw(NOTATION_TOP) && IsToDraw(NOTATION_BOTTOM))) {
    // center the menclose around the content (vertically)
    nscoord dy = std::max(aDesiredSize.TopAscent() - bmBase.ascent,
                        aDesiredSize.Height() - aDesiredSize.TopAscent() -
                        bmBase.descent);

    aDesiredSize.SetTopAscent(bmBase.ascent + dy);
    aDesiredSize.Height() = aDesiredSize.TopAscent() + bmBase.descent + dy;
  }

  // Update mBoundingMetrics ascent/descent
  if (IsToDraw(NOTATION_TOP) ||
      IsToDraw(NOTATION_RIGHT) ||
      IsToDraw(NOTATION_LEFT) ||
      IsToDraw(NOTATION_UPDIAGONALSTRIKE) ||
      IsToDraw(NOTATION_UPDIAGONALARROW) ||
      IsToDraw(NOTATION_DOWNDIAGONALSTRIKE) ||
      IsToDraw(NOTATION_VERTICALSTRIKE) ||
      IsToDraw(NOTATION_CIRCLE) ||
      IsToDraw(NOTATION_ROUNDEDBOX))
    mBoundingMetrics.ascent = aDesiredSize.TopAscent();
  
  if (IsToDraw(NOTATION_BOTTOM) ||
      IsToDraw(NOTATION_RIGHT) ||
      IsToDraw(NOTATION_LEFT) ||
      IsToDraw(NOTATION_UPDIAGONALSTRIKE) ||
      IsToDraw(NOTATION_UPDIAGONALARROW) ||
      IsToDraw(NOTATION_DOWNDIAGONALSTRIKE) ||
      IsToDraw(NOTATION_VERTICALSTRIKE) ||
      IsToDraw(NOTATION_CIRCLE) ||
      IsToDraw(NOTATION_ROUNDEDBOX))
    mBoundingMetrics.descent = aDesiredSize.Height() - aDesiredSize.TopAscent();

  aDesiredSize.mBoundingMetrics = mBoundingMetrics;
  
  mReference.x = 0;
  mReference.y = aDesiredSize.TopAscent();

  if (aPlaceOrigin) {
    //////////////////
    // Set position and size of MathMLChars
    if (IsToDraw(NOTATION_LONGDIV))
      mMathMLChar[mLongDivCharIndex].SetRect(nsRect(dx_left -
                                                    bmLongdivChar.width,
                                                    aDesiredSize.TopAscent() -
                                                    longdivAscent,
                                                    bmLongdivChar.width,
                                                    bmLongdivChar.ascent +
                                                    bmLongdivChar.descent));

    if (IsToDraw(NOTATION_RADICAL)) {
      nscoord dx = (StyleVisibility()->mDirection ?
                    dx_left + bmBase.width : dx_left - bmRadicalChar.width);

      mMathMLChar[mRadicalCharIndex].SetRect(nsRect(dx,
                                                    aDesiredSize.TopAscent() -
                                                    radicalAscent,
                                                    bmRadicalChar.width,
                                                    bmRadicalChar.ascent +
                                                    bmRadicalChar.descent));
    }

    mContentWidth = bmBase.width;

    //////////////////
    // Finish reflowing child frames
    PositionRowChildFrames(dx_left, aDesiredSize.TopAscent());
  }

  return NS_OK;
}
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.GetWritingMode(),
                                         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,
                          0, /* i.e., without embellishments */
                          stretchDir, containerSize);
  childFrame = firstChild;
  while (childFrame) {
    nsIMathMLFrame* mathmlChild = do_QueryFrame(childFrame);
    if (mathmlChild) {
      nsHTMLReflowMetrics childDesiredSize(aReflowState.GetWritingMode());
      // 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.GetWritingMode());
    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;
}
Exemple #9
0
NS_IMETHODIMP
nsMathMLmrootFrame::Reflow(nsPresContext*          aPresContext,
                           nsHTMLReflowMetrics&     aDesiredSize,
                           const nsHTMLReflowState& aReflowState,
                           nsReflowStatus&          aStatus)
{
  nsresult rv = NS_OK;
  nsSize availSize(aReflowState.ComputedWidth(), NS_UNCONSTRAINEDSIZE);
  nsReflowStatus childStatus;

  aDesiredSize.Width() = aDesiredSize.Height() = 0;
  aDesiredSize.SetTopAscent(0);

  nsBoundingMetrics bmSqr, bmBase, bmIndex;
  nsRenderingContext& renderingContext = *aReflowState.rendContext;

  //////////////////
  // Reflow Children

  int32_t count = 0;
  nsIFrame* baseFrame = nullptr;
  nsIFrame* indexFrame = nullptr;
  nsHTMLReflowMetrics baseSize(aReflowState.GetWritingMode());
  nsHTMLReflowMetrics indexSize(aReflowState.GetWritingMode());
  nsIFrame* childFrame = mFrames.FirstChild();
  while (childFrame) {
    // ask our children to compute their bounding metrics 
    nsHTMLReflowMetrics childDesiredSize(aReflowState.GetWritingMode(),
                                         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(mFrames.FirstChild(), childFrame);
      return rv;
    }
    if (0 == count) {
      // base 
      baseFrame = childFrame;
      baseSize = childDesiredSize;
      bmBase = childDesiredSize.mBoundingMetrics;
    }
    else if (1 == count) {
      // index
      indexFrame = childFrame;
      indexSize = childDesiredSize;
      bmIndex = childDesiredSize.mBoundingMetrics;
    }
    count++;
    childFrame = childFrame->GetNextSibling();
  }
  if (2 != count) {
    // report an error, encourage people to get their markups in order
    ReportChildCountError();
    rv = ReflowError(renderingContext, aDesiredSize);
    aStatus = NS_FRAME_COMPLETE;
    NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
    // Call DidReflow() for the child frames we successfully did reflow.
    DidReflowChildren(mFrames.FirstChild(), childFrame);
    return rv;
  }

  ////////////
  // Prepare the radical symbol and the overline bar

  nsRefPtr<nsFontMetrics> fm;
  nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
  renderingContext.SetFont(fm);

  // For radical glyphs from TeX fonts and some of the radical glyphs from
  // Mathematica fonts, the thickness of the overline can be obtained from the
  // ascent of the glyph.  Most fonts however have radical glyphs above the
  // baseline so no assumption can be made about the meaning of the ascent.
  nscoord ruleThickness, leading, em;
  GetRuleThickness(renderingContext, fm, ruleThickness);

  char16_t one = '1';
  nsBoundingMetrics bmOne = renderingContext.GetBoundingMetrics(&one, 1);

  // get the leading to be left at the top of the resulting frame
  // this seems more reliable than using fm->GetLeading() on suspicious fonts
  GetEmHeight(fm, em);
  leading = nscoord(0.2f * em); 

  // Rule 11, App. G, TeXbook
  // psi = clearance between rule and content
  nscoord phi = 0, psi = 0;
  if (StyleFont()->mMathDisplay == NS_MATHML_DISPLAYSTYLE_BLOCK)
    phi = fm->XHeight();
  else
    phi = ruleThickness;
  psi = ruleThickness + phi/4;

  // built-in: adjust clearance psi to emulate \mathstrut using '1' (TexBook, p.131)
  if (bmOne.ascent > bmBase.ascent)
    psi += bmOne.ascent - bmBase.ascent;

  // make sure that the rule appears on on screen
  nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
  if (ruleThickness < onePixel) {
    ruleThickness = onePixel;
  }

  // adjust clearance psi to get an exact number of pixels -- this
  // gives a nicer & uniform look on stacked radicals (bug 130282)
  nscoord delta = psi % onePixel;
  if (delta)
    psi += onePixel - delta; // round up

  // Stretch the radical symbol to the appropriate height if it is not big enough.
  nsBoundingMetrics contSize = bmBase;
  contSize.descent = bmBase.ascent + bmBase.descent + psi;
  contSize.ascent = ruleThickness;

  // height(radical) should be >= height(base) + psi + ruleThickness
  nsBoundingMetrics radicalSize;
  mSqrChar.Stretch(aPresContext, renderingContext,
                   NS_STRETCH_DIRECTION_VERTICAL, 
                   contSize, radicalSize,
                   NS_STRETCH_LARGER,
                   StyleVisibility()->mDirection);
  // radicalSize have changed at this point, and should match with
  // the bounding metrics of the char
  mSqrChar.GetBoundingMetrics(bmSqr);

  // Update the desired size for the container (like msqrt, index is not yet included)
  // the baseline will be that of the base.
  mBoundingMetrics.ascent = bmBase.ascent + psi + ruleThickness;
  mBoundingMetrics.descent = 
    std::max(bmBase.descent,
           (bmSqr.ascent + bmSqr.descent - mBoundingMetrics.ascent));
  mBoundingMetrics.width = bmSqr.width + bmBase.width;
  mBoundingMetrics.leftBearing = bmSqr.leftBearing;
  mBoundingMetrics.rightBearing = bmSqr.width + 
    std::max(bmBase.width, bmBase.rightBearing); // take also care of the rule

  aDesiredSize.SetTopAscent(mBoundingMetrics.ascent + leading);
  aDesiredSize.Height() = aDesiredSize.TopAscent() +
    std::max(baseSize.Height() - baseSize.TopAscent(),
           mBoundingMetrics.descent + ruleThickness);
  aDesiredSize.Width() = mBoundingMetrics.width;

  /////////////
  // Re-adjust the desired size to include the index.
  
  // the index is raised by some fraction of the height
  // of the radical, see \mroot macro in App. B, TexBook
  nscoord raiseIndexDelta = NSToCoordRound(0.6f * (bmSqr.ascent + bmSqr.descent));
  nscoord indexRaisedAscent = mBoundingMetrics.ascent // top of radical 
    - (bmSqr.ascent + bmSqr.descent) // to bottom of radical
    + raiseIndexDelta + bmIndex.ascent + bmIndex.descent; // to top of raised index

  nscoord indexClearance = 0;
  if (mBoundingMetrics.ascent < indexRaisedAscent) {
    indexClearance = 
      indexRaisedAscent - mBoundingMetrics.ascent; // excess gap introduced by a tall index 
    mBoundingMetrics.ascent = indexRaisedAscent;
    nscoord descent = aDesiredSize.Height() - aDesiredSize.TopAscent();
    aDesiredSize.SetTopAscent(mBoundingMetrics.ascent + leading);
    aDesiredSize.Height() = aDesiredSize.TopAscent() + descent;
  }

  nscoord dxIndex, dxSqr;
  GetRadicalXOffsets(bmIndex.width, bmSqr.width, fm, &dxIndex, &dxSqr);

  mBoundingMetrics.width = dxSqr + bmSqr.width + bmBase.width;
  mBoundingMetrics.leftBearing = 
    std::min(dxIndex + bmIndex.leftBearing, dxSqr + bmSqr.leftBearing);
  mBoundingMetrics.rightBearing = dxSqr + bmSqr.width +
    std::max(bmBase.width, bmBase.rightBearing);

  aDesiredSize.Width() = mBoundingMetrics.width;
  aDesiredSize.mBoundingMetrics = mBoundingMetrics;
  GatherAndStoreOverflow(&aDesiredSize);

  // place the index
  nscoord dx = dxIndex;
  nscoord dy = aDesiredSize.TopAscent() - (indexRaisedAscent + indexSize.TopAscent() - bmIndex.ascent);
  FinishReflowChild(indexFrame, aPresContext, indexSize, nullptr,
                    MirrorIfRTL(aDesiredSize.Width(), indexSize.Width(), dx),
                    dy, 0);

  // place the radical symbol and the radical bar
  dx = dxSqr;
  dy = indexClearance + leading; // leave a leading at the top
  mSqrChar.SetRect(nsRect(MirrorIfRTL(aDesiredSize.Width(), bmSqr.width, dx),
                          dy, bmSqr.width, bmSqr.ascent + bmSqr.descent));
  dx += bmSqr.width;
  mBarRect.SetRect(MirrorIfRTL(aDesiredSize.Width(), bmBase.width, dx),
                   dy, bmBase.width, ruleThickness);

  // place the base
  dy = aDesiredSize.TopAscent() - baseSize.TopAscent();
  FinishReflowChild(baseFrame, aPresContext, baseSize, nullptr,
                    MirrorIfRTL(aDesiredSize.Width(), baseSize.Width(), dx),
                    dy, 0);

  mReference.x = 0;
  mReference.y = aDesiredSize.TopAscent();

  aStatus = NS_FRAME_COMPLETE;
  NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
  return NS_OK;
}
Exemple #10
0
// exported routine that both munderover and mmultiscripts share.
// munderover uses this when movablelimits is set.
nsresult
nsMathMLmmultiscriptsFrame::PlaceMultiScript(nsPresContext*      aPresContext,
                                        nsRenderingContext& aRenderingContext,
                                        bool                 aPlaceOrigin,
                                        nsHTMLReflowMetrics& aDesiredSize,
                                        nsMathMLContainerFrame* aFrame,
                                        nscoord              aUserSubScriptShift,
                                        nscoord              aUserSupScriptShift,
                                        nscoord              aScriptSpace)
{
  nsIAtom* tag = aFrame->GetContent()->Tag();

  // This function deals with both munderover etc. as well as msubsup etc.
  // As the former behaves identically to the later, we treat it as such
  // to avoid additional checks later.
  if (tag == nsGkAtoms::mover_)
    tag = nsGkAtoms::msup_;
  else if (tag == nsGkAtoms::munder_)
    tag = nsGkAtoms::msub_;
  else if (tag  == nsGkAtoms::munderover_)
    tag = nsGkAtoms::msubsup_;

  nsBoundingMetrics bmFrame;

  nscoord minShiftFromXHeight, subDrop, supDrop;

  ////////////////////////////////////////
  // Initialize super/sub shifts that
  // depend only on the current font
  ////////////////////////////////////////

  nsIFrame* baseFrame = aFrame->GetFirstPrincipalChild();

  if (!baseFrame) {
    if (tag == nsGkAtoms::mmultiscripts_)
      aFrame->ReportErrorToConsole("NoBase");
    else
      aFrame->ReportChildCountError();
    return aFrame->ReflowError(aRenderingContext, aDesiredSize);
  }


  // get x-height (an ex)
  const nsStyleFont* font = aFrame->StyleFont();
  nsRefPtr<nsFontMetrics> fm;
  nsLayoutUtils::GetFontMetricsForFrame(baseFrame, getter_AddRefs(fm));
  aRenderingContext.SetFont(fm);

  nscoord xHeight = fm->XHeight();

  nscoord ruleSize;
  GetRuleThickness (aRenderingContext, fm, ruleSize);

  // force the scriptSpace to be at least 1 pixel
  nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
  aScriptSpace = std::max(onePixel, aScriptSpace);

  /////////////////////////////////////
  // first the shift for the subscript

  // subScriptShift{1,2}
  // = minimum amount to shift the subscript down
  // = sub{1,2} in TeXbook
  // subScriptShift1 = subscriptshift attribute * x-height
  nscoord subScriptShift1, subScriptShift2;

  // Get subScriptShift{1,2} default from font
  GetSubScriptShifts (fm, subScriptShift1, subScriptShift2);
  nscoord subScriptShift;
  if (tag == nsGkAtoms::msub_) {
    subScriptShift = subScriptShift1;
  } else {
    subScriptShift = std::max(subScriptShift1, subScriptShift2);
  }
  if (0 < aUserSubScriptShift) {
    // the user has set the subscriptshift attribute
    subScriptShift = std::max(subScriptShift, aUserSubScriptShift);
  }

  /////////////////////////////////////
  // next the shift for the superscript

  // supScriptShift{1,2,3}
  // = minimum amount to shift the supscript up
  // = sup{1,2,3} in TeX
  // supScriptShift1 = superscriptshift attribute * x-height
  // Note that there are THREE values for supscript shifts depending
  // on the current style
  nscoord supScriptShift1, supScriptShift2, supScriptShift3;
  // Set supScriptShift{1,2,3} default from font
  GetSupScriptShifts (fm, supScriptShift1, supScriptShift2, supScriptShift3);

  // get sup script shift depending on current script level and display style
  // Rule 18c, App. G, TeXbook
  nsPresentationData presentationData;
  aFrame->GetPresentationData(presentationData);
  nscoord supScriptShift;
  if (font->mScriptLevel == 0 &&
      font->mMathDisplay == NS_MATHML_DISPLAYSTYLE_BLOCK &&
      !NS_MATHML_IS_COMPRESSED(presentationData.flags)) {
    // Style D in TeXbook
    supScriptShift = supScriptShift1;
  } else if (NS_MATHML_IS_COMPRESSED(presentationData.flags)) {
    // Style C' in TeXbook = D',T',S',SS'
    supScriptShift = supScriptShift3;
  } else {
    // everything else = T,S,SS
    supScriptShift = supScriptShift2;
  }

  if (0 < aUserSupScriptShift) {
    // the user has set the supscriptshift attribute
    supScriptShift = std::max(supScriptShift, aUserSupScriptShift);
  }

  ////////////////////////////////////
  // Get the children's sizes
  ////////////////////////////////////

  const WritingMode wm(aDesiredSize.GetWritingMode());
  nscoord width = 0, prescriptsWidth = 0, rightBearing = 0;
  nscoord minSubScriptShift = 0, minSupScriptShift = 0;
  nscoord trySubScriptShift = subScriptShift;
  nscoord trySupScriptShift = supScriptShift;
  nscoord maxSubScriptShift = subScriptShift;
  nscoord maxSupScriptShift = supScriptShift;
  nsHTMLReflowMetrics baseSize(wm);
  nsHTMLReflowMetrics subScriptSize(wm);
  nsHTMLReflowMetrics supScriptSize(wm);
  nsHTMLReflowMetrics multiSubSize(wm), multiSupSize(wm);
  baseFrame = nullptr;
  nsIFrame* subScriptFrame = nullptr;
  nsIFrame* supScriptFrame = nullptr;
  nsIFrame* prescriptsFrame = nullptr; // frame of <mprescripts/>, if there.

  bool firstPrescriptsPair = false;
  nsBoundingMetrics bmBase, bmSubScript, bmSupScript, bmMultiSub, bmMultiSup;
  multiSubSize.SetTopAscent(-0x7FFFFFFF);
  multiSupSize.SetTopAscent(-0x7FFFFFFF);
  bmMultiSub.ascent = bmMultiSup.ascent = -0x7FFFFFFF;
  bmMultiSub.descent = bmMultiSup.descent = -0x7FFFFFFF;
  nscoord italicCorrection = 0;

  nsBoundingMetrics boundingMetrics;
  boundingMetrics.width = 0;
  boundingMetrics.ascent = boundingMetrics.descent = -0x7FFFFFFF;
  aDesiredSize.Width() = aDesiredSize.Height() = 0;

  int32_t count = 0;
  bool foundNoneTag = false;

  // Boolean to determine whether the current child is a subscript.
  // Note that only msup starts with a superscript.
  bool isSubScript = (tag != nsGkAtoms::msup_);

  nsIFrame* childFrame = aFrame->GetFirstPrincipalChild();
  while (childFrame) {
    nsIAtom* childTag = childFrame->GetContent()->Tag();
    if (childTag == nsGkAtoms::mprescripts_) {
      if (tag != nsGkAtoms::mmultiscripts_) {
        if (aPlaceOrigin) {
          aFrame->ReportInvalidChildError(childTag);
        }
        return aFrame->ReflowError(aRenderingContext, aDesiredSize);
      }
      if (prescriptsFrame) {
        // duplicate <mprescripts/> found
        // report an error, encourage people to get their markups in order
        if (aPlaceOrigin) {
          aFrame->ReportErrorToConsole("DuplicateMprescripts");
        }
        return aFrame->ReflowError(aRenderingContext, aDesiredSize);
      }
      if (!isSubScript) {
        if (aPlaceOrigin) {
          aFrame->ReportErrorToConsole("SubSupMismatch");
        }
        return aFrame->ReflowError(aRenderingContext, aDesiredSize);
      }

      prescriptsFrame = childFrame;
      firstPrescriptsPair = true;
    } else if (0 == count) {
      // base

      if (childTag == nsGkAtoms::none) {
        if (tag == nsGkAtoms::mmultiscripts_) {
          if (aPlaceOrigin) {
            aFrame->ReportErrorToConsole("NoBase");
          }
          return aFrame->ReflowError(aRenderingContext, aDesiredSize);
        } else {
          //A different error message is triggered later for the other tags
          foundNoneTag = true;
        }
      }
      baseFrame = childFrame;
      GetReflowAndBoundingMetricsFor(baseFrame, baseSize, bmBase);

      if (tag != nsGkAtoms::msub_) {
        // Apply italics correction if there is the potential for a 
        // postsupscript.
        GetItalicCorrection(bmBase, italicCorrection);
        // If italics correction is applied, we always add "a little to spare"
        // (see TeXbook Ch.11, p.64), as we estimate the italic creation
        // ourselves and it isn't the same as TeX.
        italicCorrection += onePixel;
      }

      // we update boundingMetrics.{ascent,descent} with that
      // of the baseFrame only after processing all the sup/sub pairs
      // XXX need italic correction only *if* there are postscripts ?
      boundingMetrics.width = bmBase.width + italicCorrection;
      boundingMetrics.rightBearing = bmBase.rightBearing;
      boundingMetrics.leftBearing = bmBase.leftBearing; // until overwritten
    } else {
      // super/subscript block
      if ( childTag == nsGkAtoms::none) {
        foundNoneTag = true;
      }

      if (isSubScript) {
        // subscript
        subScriptFrame = childFrame;
        GetReflowAndBoundingMetricsFor(subScriptFrame, subScriptSize, bmSubScript);
        // get the subdrop from the subscript font
        GetSubDropFromChild (subScriptFrame, subDrop);
        // parameter v, Rule 18a, App. G, TeXbook
        minSubScriptShift = bmBase.descent + subDrop;
        trySubScriptShift = std::max(minSubScriptShift,subScriptShift);
        multiSubSize.SetTopAscent(std::max(multiSubSize.TopAscent(),
                                       subScriptSize.TopAscent()));
        bmMultiSub.ascent = std::max(bmMultiSub.ascent, bmSubScript.ascent);
        bmMultiSub.descent = std::max(bmMultiSub.descent, bmSubScript.descent);
        multiSubSize.Height() = 
          std::max(multiSubSize.Height(),
                   subScriptSize.Height() - subScriptSize.TopAscent());
        if (bmSubScript.width)
          width = bmSubScript.width + aScriptSpace;
        rightBearing = bmSubScript.rightBearing;

        if (tag == nsGkAtoms::msub_) {
          boundingMetrics.rightBearing = boundingMetrics.width + rightBearing;
          boundingMetrics.width += width;

          // get min subscript shift limit from x-height
          // = h(x) - 4/5 * sigma_5, Rule 18b, App. G, TeXbook
          nscoord minShiftFromXHeight = (nscoord) 
            (bmSubScript.ascent - (4.0f/5.0f) * xHeight);
          maxSubScriptShift = std::max(trySubScriptShift,minShiftFromXHeight);

          maxSubScriptShift = std::max(maxSubScriptShift, trySubScriptShift);
          trySubScriptShift = subScriptShift;
        }
      } else {
        // supscript
        supScriptFrame = childFrame;
        GetReflowAndBoundingMetricsFor(supScriptFrame, supScriptSize, bmSupScript);
        // get the supdrop from the supscript font
        GetSupDropFromChild (supScriptFrame, supDrop);
        // parameter u, Rule 18a, App. G, TeXbook
        minSupScriptShift = bmBase.ascent - supDrop;
        // get min supscript shift limit from x-height
        // = d(x) + 1/4 * sigma_5, Rule 18c, App. G, TeXbook
        minShiftFromXHeight = NSToCoordRound
          ((bmSupScript.descent + (1.0f/4.0f) * xHeight));
        trySupScriptShift = std::max(minSupScriptShift,
                                     std::max(minShiftFromXHeight,
                                              supScriptShift));
        multiSupSize.SetTopAscent(std::max(multiSupSize.TopAscent(),
                                       supScriptSize.TopAscent()));
        bmMultiSup.ascent = std::max(bmMultiSup.ascent, bmSupScript.ascent);
        bmMultiSup.descent = std::max(bmMultiSup.descent, bmSupScript.descent);
        multiSupSize.Height() = 
          std::max(multiSupSize.Height(),
                   supScriptSize.Height() - supScriptSize.TopAscent());

        if (bmSupScript.width)
          width = std::max(width, bmSupScript.width + aScriptSpace);
        rightBearing = std::max(rightBearing, bmSupScript.rightBearing);

        if (!prescriptsFrame) { // we are still looping over base & postscripts
          boundingMetrics.rightBearing = boundingMetrics.width + rightBearing;
          boundingMetrics.width += width;
        } else {
          prescriptsWidth += width;
          if (firstPrescriptsPair) {
            firstPrescriptsPair = false;
            boundingMetrics.leftBearing =
              std::min(bmSubScript.leftBearing, bmSupScript.leftBearing);
          }
        }
        width = rightBearing = 0;

        // negotiate between the various shifts so that
        // there is enough gap between the sup and subscripts
        // Rule 18e, App. G, TeXbook
        if (tag == nsGkAtoms::mmultiscripts_ || 
            tag == nsGkAtoms::msubsup_) {
          nscoord gap =
            (trySupScriptShift - bmSupScript.descent) -
            (bmSubScript.ascent - trySubScriptShift);
          if (gap < 4.0f * ruleSize) {
            // adjust trySubScriptShift to get a gap of (4.0 * ruleSize)
            trySubScriptShift += NSToCoordRound ((4.0f * ruleSize) - gap);
          }

          // next we want to ensure that the bottom of the superscript
          // will be > (4/5) * x-height above baseline
          gap = NSToCoordRound ((4.0f/5.0f) * xHeight -
                  (trySupScriptShift - bmSupScript.descent));
          if (gap > 0) {
            trySupScriptShift += gap;
            trySubScriptShift -= gap;
          }
        }

        maxSubScriptShift = std::max(maxSubScriptShift, trySubScriptShift);
        maxSupScriptShift = std::max(maxSupScriptShift, trySupScriptShift);

        trySubScriptShift = subScriptShift;
        trySupScriptShift = supScriptShift;
      }

      isSubScript = !isSubScript;
    }
    count++;
    childFrame = childFrame->GetNextSibling();
  }

  //NoBase error may also have been reported above
  if ((count != 2 && (tag == nsGkAtoms::msup_ || tag == nsGkAtoms::msub_)) ||
      (count != 3 && tag == nsGkAtoms::msubsup_) || !baseFrame ||
      (foundNoneTag && tag != nsGkAtoms::mmultiscripts_) ||
      (!isSubScript && tag == nsGkAtoms::mmultiscripts_)) {
    // report an error, encourage people to get their markups in order
    if (aPlaceOrigin) {
      if ((count != 2 && (tag == nsGkAtoms::msup_ || 
          tag == nsGkAtoms::msub_)) ||
          (count != 3 && tag == nsGkAtoms::msubsup_ )) {
        aFrame->ReportChildCountError();
      } else if (foundNoneTag && tag != nsGkAtoms::mmultiscripts_) {
        aFrame->ReportInvalidChildError(nsGkAtoms::none);
      } else if (!baseFrame) {
        aFrame->ReportErrorToConsole("NoBase");
      } else {
        aFrame->ReportErrorToConsole("SubSupMismatch");
      }
    }
    return aFrame->ReflowError(aRenderingContext, aDesiredSize);
  }

  // we left out the width of prescripts, so ...
  boundingMetrics.rightBearing += prescriptsWidth;
  boundingMetrics.width += prescriptsWidth;

  // Zero out the shifts in where a frame isn't present to avoid the potential
  // for overflow.
  if (!subScriptFrame)
    maxSubScriptShift = 0;
  if (!supScriptFrame)
    maxSupScriptShift = 0;

  // we left out the base during our bounding box updates, so ...
  if (tag == nsGkAtoms::msub_) {
    boundingMetrics.ascent = std::max(bmBase.ascent,
                                      bmMultiSub.ascent - maxSubScriptShift);
  } else {
    boundingMetrics.ascent =
      std::max(bmBase.ascent, (bmMultiSup.ascent + maxSupScriptShift));
  }
  if (tag == nsGkAtoms::msup_) {
    boundingMetrics.descent = std::max(bmBase.descent,
                                       bmMultiSup.descent - maxSupScriptShift);
  } else {
    boundingMetrics.descent =
      std::max(bmBase.descent, (bmMultiSub.descent + maxSubScriptShift));
  }
  aFrame->SetBoundingMetrics(boundingMetrics);

  // get the reflow metrics ...
  aDesiredSize.SetTopAscent( 
    std::max(baseSize.TopAscent(), 
             std::max(multiSubSize.TopAscent() - maxSubScriptShift,
                      multiSupSize.TopAscent() + maxSupScriptShift)));
  aDesiredSize.Height() = aDesiredSize.TopAscent() +
    std::max(baseSize.Height() - baseSize.TopAscent(),
             std::max(multiSubSize.Height() + maxSubScriptShift,
                      multiSupSize.Height() - maxSupScriptShift));
  aDesiredSize.Width() = boundingMetrics.width;
  aDesiredSize.mBoundingMetrics = boundingMetrics;

  aFrame->SetReference(nsPoint(0, aDesiredSize.TopAscent()));

  //////////////////
  // Place Children

  // Place prescripts, followed by base, and then postscripts.
  // The list of frames is in the order: {base} {postscripts} {prescripts}
  // We go over the list in a circular manner, starting at <prescripts/>

  if (aPlaceOrigin) {
    nscoord dx = 0, dy = 0;

    // With msub and msup there is only one element and 
    // subscriptFrame/supScriptFrame have already been set above where
    // relevant.  In these cases we skip to the reflow part.
    if (tag == nsGkAtoms::msub_ || tag == nsGkAtoms::msup_)
      count = 1;
    else
      count = 0;
    childFrame = prescriptsFrame;
    bool isPreScript = true;
    do {
      if (!childFrame) { // end of prescripts,
        isPreScript = false;
        // place the base ...
        childFrame = baseFrame;
        dy = aDesiredSize.TopAscent() - baseSize.TopAscent();
        FinishReflowChild (baseFrame, aPresContext, baseSize, nullptr,
                           aFrame->MirrorIfRTL(aDesiredSize.Width(),
                                               baseSize.Width(),
                                               dx),
                           dy, 0);
        dx += bmBase.width + italicCorrection;
      } else if (prescriptsFrame != childFrame) {
        // process each sup/sub pair
        if (0 == count) {
          subScriptFrame = childFrame;
          count = 1;
        } else if (1 == count) {
          if (tag != nsGkAtoms::msub_)
            supScriptFrame = childFrame;
          count = 0;

          // get the ascent/descent of sup/subscripts stored in their rects
          // rect.x = descent, rect.y = ascent
          if (subScriptFrame)
            GetReflowAndBoundingMetricsFor(subScriptFrame, subScriptSize, bmSubScript);
          if (supScriptFrame)
            GetReflowAndBoundingMetricsFor(supScriptFrame, supScriptSize, bmSupScript);

          width = std::max(subScriptSize.Width(), supScriptSize.Width());

          if (subScriptFrame) {
            nscoord x = dx;
            // prescripts should be right aligned
            // https://bugzilla.mozilla.org/show_bug.cgi?id=928675
            if (isPreScript)
              x += width - subScriptSize.Width();
            dy = aDesiredSize.TopAscent() - subScriptSize.TopAscent() +
              maxSubScriptShift;
            FinishReflowChild (subScriptFrame, aPresContext, subScriptSize,
                               nullptr,
                               aFrame->MirrorIfRTL(aDesiredSize.Width(),
                                                   subScriptSize.Width(),
                                                   x),
                               dy, 0);
          }

          if (supScriptFrame) {
            nscoord x = dx;
            if (isPreScript)
              x += width - supScriptSize.Width();
            dy = aDesiredSize.TopAscent() - supScriptSize.TopAscent() -
              maxSupScriptShift;
            FinishReflowChild (supScriptFrame, aPresContext, supScriptSize,
                               nullptr,
                               aFrame->MirrorIfRTL(aDesiredSize.Width(),
                                                   supScriptSize.Width(),
                                                   x),
                               dy, 0);
          }
          dx += width + aScriptSpace;
        }
      }
      childFrame = childFrame->GetNextSibling();
    } while (prescriptsFrame != childFrame);
  }

  return NS_OK;
}
Exemple #11
0
// NOTE: aDesiredStretchSize is an IN/OUT parameter
//       On input  - it contains our current size
//       On output - the same size or the new size that we want
NS_IMETHODIMP
nsMathMLmoFrame::Stretch(nsRenderingContext& aRenderingContext,
                         nsStretchDirection   aStretchDirection,
                         nsBoundingMetrics&   aContainerSize,
                         nsHTMLReflowMetrics& aDesiredStretchSize)
{
  if (NS_MATHML_STRETCH_WAS_DONE(mPresentationData.flags)) {
    NS_WARNING("it is wrong to fire stretch more than once on a frame");
    return NS_OK;
  }
  mPresentationData.flags |= NS_MATHML_STRETCH_DONE;

  nsIFrame* firstChild = mFrames.FirstChild();

  // get the axis height;
  nsRefPtr<nsFontMetrics> fm;
  nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
  aRenderingContext.SetFont(fm);
  nscoord axisHeight, height;
  GetAxisHeight(aRenderingContext, fm, axisHeight);

  // get the leading to be left at the top and the bottom of the stretched char
  // this seems more reliable than using fm->GetLeading() on suspicious fonts
  nscoord em;
  GetEmHeight(fm, em);
  nscoord leading = NSToCoordRound(0.2f * em);

  // Operators that are stretchy, or those that are to be centered
  // to cater for fonts that are not math-aware, are handled by the MathMLChar
  // ('form' is reset if stretch fails -- i.e., we don't bother to stretch next time)
  bool useMathMLChar = UseMathMLChar();

  nsBoundingMetrics charSize;
  nsBoundingMetrics container = aDesiredStretchSize.mBoundingMetrics;
  bool isVertical = false;

  if (((aStretchDirection == NS_STRETCH_DIRECTION_VERTICAL) ||
       (aStretchDirection == NS_STRETCH_DIRECTION_DEFAULT))  &&
      (mEmbellishData.direction == NS_STRETCH_DIRECTION_VERTICAL)) {
    isVertical = true;
  }

  uint32_t stretchHint =
    GetStretchHint(mFlags, mPresentationData, isVertical, StyleFont());

  if (useMathMLChar) {
    nsBoundingMetrics initialSize = aDesiredStretchSize.mBoundingMetrics;

    if (stretchHint != NS_STRETCH_NONE) {

      container = aContainerSize;

      // some adjustments if the operator is symmetric and vertical

      if (isVertical && NS_MATHML_OPERATOR_IS_SYMMETRIC(mFlags)) {
        // we need to center about the axis
        nscoord delta = std::max(container.ascent - axisHeight,
                               container.descent + axisHeight);
        container.ascent = delta + axisHeight;
        container.descent = delta - axisHeight;

        // get ready in case we encounter user-desired min-max size
        delta = std::max(initialSize.ascent - axisHeight,
                       initialSize.descent + axisHeight);
        initialSize.ascent = delta + axisHeight;
        initialSize.descent = delta - axisHeight;
      }

      // check for user-desired min-max size

      if (mMaxSize != NS_MATHML_OPERATOR_SIZE_INFINITY && mMaxSize > 0.0f) {
        // if we are here, there is a user defined maxsize ...
        //XXX Set stretchHint = NS_STRETCH_NORMAL? to honor the maxsize as close as possible?
        if (NS_MATHML_OPERATOR_MAXSIZE_IS_ABSOLUTE(mFlags)) {
          // there is an explicit value like maxsize="20pt"
          // try to maintain the aspect ratio of the char
          float aspect = mMaxSize / float(initialSize.ascent + initialSize.descent);
          container.ascent =
            std::min(container.ascent, nscoord(initialSize.ascent * aspect));
          container.descent =
            std::min(container.descent, nscoord(initialSize.descent * aspect));
          // below we use a type cast instead of a conversion to avoid a VC++ bug
          // see http://support.microsoft.com/support/kb/articles/Q115/7/05.ASP
          container.width =
            std::min(container.width, (nscoord)mMaxSize);
        }
        else { // multiplicative value
          container.ascent =
            std::min(container.ascent, nscoord(initialSize.ascent * mMaxSize));
          container.descent =
            std::min(container.descent, nscoord(initialSize.descent * mMaxSize));
          container.width =
            std::min(container.width, nscoord(initialSize.width * mMaxSize));
        }

        if (isVertical && !NS_MATHML_OPERATOR_IS_SYMMETRIC(mFlags)) {
          // re-adjust to align the char with the bottom of the initial container
          height = container.ascent + container.descent;
          container.descent = aContainerSize.descent;
          container.ascent = height - container.descent;
        }
      }

      if (mMinSize > 0.0f) {
        // if we are here, there is a user defined minsize ...
        // always allow the char to stretch in its natural direction,
        // even if it is different from the caller's direction 
        if (aStretchDirection != NS_STRETCH_DIRECTION_DEFAULT &&
            aStretchDirection != mEmbellishData.direction) {
          aStretchDirection = NS_STRETCH_DIRECTION_DEFAULT;
          // but when we are not honoring the requested direction
          // we should not use the caller's container size either
          container = initialSize;
        }
        if (NS_MATHML_OPERATOR_MINSIZE_IS_ABSOLUTE(mFlags)) {
          // there is an explicit value like minsize="20pt"
          // try to maintain the aspect ratio of the char
          float aspect = mMinSize / float(initialSize.ascent + initialSize.descent);
          container.ascent =
            std::max(container.ascent, nscoord(initialSize.ascent * aspect));
          container.descent =
            std::max(container.descent, nscoord(initialSize.descent * aspect));
          container.width =
            std::max(container.width, (nscoord)mMinSize);
        }
        else { // multiplicative value
          container.ascent =
            std::max(container.ascent, nscoord(initialSize.ascent * mMinSize));
          container.descent =
            std::max(container.descent, nscoord(initialSize.descent * mMinSize));
          container.width =
            std::max(container.width, nscoord(initialSize.width * mMinSize));
        }

        if (isVertical && !NS_MATHML_OPERATOR_IS_SYMMETRIC(mFlags)) {
          // re-adjust to align the char with the bottom of the initial container
          height = container.ascent + container.descent;
          container.descent = aContainerSize.descent;
          container.ascent = height - container.descent;
        }
      }
    }

    // let the MathMLChar stretch itself...
    nsresult res = mMathMLChar.Stretch(PresContext(), aRenderingContext,
                                       aStretchDirection, container, charSize,
                                       stretchHint,
                                       StyleVisibility()->mDirection);
    if (NS_FAILED(res)) {
      // gracefully handle cases where stretching the char failed (i.e., GetBoundingMetrics failed)
      // clear our 'form' to behave as if the operator wasn't in the dictionary
      mFlags &= ~NS_MATHML_OPERATOR_FORM;
      useMathMLChar = false;
    }
  }

  // Place our children using the default method
  // This will allow our child text frame to get its DidReflow()
  nsresult rv = Place(aRenderingContext, true, aDesiredStretchSize);
  if (NS_MATHML_HAS_ERROR(mPresentationData.flags) || NS_FAILED(rv)) {
    // Make sure the child frames get their DidReflow() calls.
    DidReflowChildren(mFrames.FirstChild());
  }

  if (useMathMLChar) {
    // update our bounding metrics... it becomes that of our MathML char
    mBoundingMetrics = charSize;

    // if the returned direction is 'unsupported', the char didn't actually change. 
    // So we do the centering only if necessary
    if (mMathMLChar.GetStretchDirection() != NS_STRETCH_DIRECTION_UNSUPPORTED ||
        NS_MATHML_OPERATOR_IS_CENTERED(mFlags)) {

      bool largeopOnly =
        (NS_STRETCH_LARGEOP & stretchHint) != 0 &&
        (NS_STRETCH_VARIABLE_MASK & stretchHint) == 0;

      if (isVertical || NS_MATHML_OPERATOR_IS_CENTERED(mFlags)) {
        // the desired size returned by mMathMLChar maybe different
        // from the size of the container.
        // the mMathMLChar.mRect.y calculation is subtle, watch out!!!

        height = mBoundingMetrics.ascent + mBoundingMetrics.descent;
        if (NS_MATHML_OPERATOR_IS_SYMMETRIC(mFlags) ||
            NS_MATHML_OPERATOR_IS_CENTERED(mFlags)) {
          // For symmetric and vertical operators, or for operators that are always
          // centered ('+', '*', etc) we want to center about the axis of the container
          mBoundingMetrics.descent = height/2 - axisHeight;
        } else if (!largeopOnly) {
          // Align the center of the char with the center of the container
          mBoundingMetrics.descent = height/2 +
            (container.ascent + container.descent)/2 - container.ascent;
        } // else align the baselines
        mBoundingMetrics.ascent = height - mBoundingMetrics.descent;
      }
    }
  }

  // Fixup for the final height.
  // On one hand, our stretchy height can sometimes be shorter than surrounding
  // ASCII chars, e.g., arrow symbols have |mBoundingMetrics.ascent + leading|
  // that is smaller than the ASCII's ascent, hence when painting the background
  // later, it won't look uniform along the line.
  // On the other hand, sometimes we may leave too much gap when our glyph happens
  // to come from a font with tall glyphs. For example, since CMEX10 has very tall
  // glyphs, its natural font metrics are large, even if we pick a small glyph
  // whose size is comparable to the size of a normal ASCII glyph.
  // So to avoid uneven spacing in either of these two cases, we use the height
  // of the ASCII font as a reference and try to match it if possible.

  // special case for accents... keep them short to improve mouse operations...
  // an accent can only be the non-first child of <mover>, <munder>, <munderover>
  bool isAccent =
    NS_MATHML_EMBELLISH_IS_ACCENT(mEmbellishData.flags);
  if (isAccent) {
    nsEmbellishData parentData;
    GetEmbellishDataFrom(mParent, parentData);
    isAccent =
       (NS_MATHML_EMBELLISH_IS_ACCENTOVER(parentData.flags) ||
        NS_MATHML_EMBELLISH_IS_ACCENTUNDER(parentData.flags)) &&
       parentData.coreFrame != this;
  }
  if (isAccent && firstChild) {
    // see bug 188467 for what is going on here
    nscoord dy = aDesiredStretchSize.TopAscent() - (mBoundingMetrics.ascent + leading);
    aDesiredStretchSize.SetTopAscent(mBoundingMetrics.ascent + leading);
    aDesiredStretchSize.Height() = aDesiredStretchSize.TopAscent() + mBoundingMetrics.descent;

    firstChild->SetPosition(firstChild->GetPosition() - nsPoint(0, dy));
  }
  else if (useMathMLChar) {
    nscoord ascent = fm->MaxAscent();
    nscoord descent = fm->MaxDescent();
    aDesiredStretchSize.SetTopAscent(std::max(mBoundingMetrics.ascent + leading, ascent));
    aDesiredStretchSize.Height() = aDesiredStretchSize.TopAscent() +
                                 std::max(mBoundingMetrics.descent + leading, descent);
  }
  aDesiredStretchSize.Width() = mBoundingMetrics.width;
  aDesiredStretchSize.mBoundingMetrics = mBoundingMetrics;
  mReference.x = 0;
  mReference.y = aDesiredStretchSize.TopAscent();
  // Place our mMathMLChar, its origin is in our coordinate system
  if (useMathMLChar) {
    nscoord dy = aDesiredStretchSize.TopAscent() - mBoundingMetrics.ascent;
    mMathMLChar.SetRect(nsRect(0, dy, charSize.width, charSize.ascent + charSize.descent));
  }

  // Before we leave... there is a last item in the check-list:
  // If our parent is not embellished, it means we are the outermost embellished
  // container and so we put the spacing, otherwise we don't include the spacing,
  // the outermost embellished container will take care of it.

  if (!NS_MATHML_OPERATOR_HAS_EMBELLISH_ANCESTOR(mFlags)) {

    // Account the spacing if we are not an accent with explicit attributes
    nscoord leadingSpace = mEmbellishData.leadingSpace;
    if (isAccent && !NS_MATHML_OPERATOR_HAS_LSPACE_ATTR(mFlags)) {
      leadingSpace = 0;
    }
    nscoord trailingSpace = mEmbellishData.trailingSpace;
    if (isAccent && !NS_MATHML_OPERATOR_HAS_RSPACE_ATTR(mFlags)) {
      trailingSpace = 0;
    }

    mBoundingMetrics.width += leadingSpace + trailingSpace;
    aDesiredStretchSize.Width() = mBoundingMetrics.width;
    aDesiredStretchSize.mBoundingMetrics.width = mBoundingMetrics.width;

    nscoord dx = (StyleVisibility()->mDirection ?
                  trailingSpace : leadingSpace);
    if (dx) {
      // adjust the offsets
      mBoundingMetrics.leftBearing += dx;
      mBoundingMetrics.rightBearing += dx;
      aDesiredStretchSize.mBoundingMetrics.leftBearing += dx;
      aDesiredStretchSize.mBoundingMetrics.rightBearing += dx;

      if (useMathMLChar) {
        nsRect rect;
        mMathMLChar.GetRect(rect);
        mMathMLChar.SetRect(nsRect(rect.x + dx, rect.y,
                                   rect.width, rect.height));
      }
      else {
        nsIFrame* childFrame = firstChild;
        while (childFrame) {
          childFrame->SetPosition(childFrame->GetPosition() +
                                  nsPoint(dx, 0));
          childFrame = childFrame->GetNextSibling();
        }
      }
    }
  }

  // Finished with these:
  ClearSavedChildMetrics();
  // Set our overflow area
  GatherAndStoreOverflow(&aDesiredStretchSize);

  // There used to be code here to change the height of the child frame to
  // change the caret height, but the text frame that manages the caret is now
  // not a direct child but wrapped in a block frame.  See also bug 412033.

  return NS_OK;
}
Exemple #12
0
nsresult
nsInlineFrame::ReflowFrames(nsPresContext* aPresContext,
                            const nsHTMLReflowState& aReflowState,
                            InlineReflowState& irs,
                            nsHTMLReflowMetrics& aMetrics,
                            nsReflowStatus& aStatus)
{
  nsresult rv = NS_OK;
  aStatus = NS_FRAME_COMPLETE;

  nsLineLayout* lineLayout = aReflowState.mLineLayout;
  bool inFirstLine = aReflowState.mLineLayout->GetInFirstLine();
  RestyleManager* restyleManager = aPresContext->RestyleManager();
  bool ltr = (NS_STYLE_DIRECTION_LTR == aReflowState.mStyleVisibility->mDirection);
  nscoord leftEdge = 0;
  // Don't offset by our start borderpadding if we have a prev continuation or
  // if we're in a part of an {ib} split other than the first one.
  if (!GetPrevContinuation() && !FrameIsNonFirstInIBSplit()) {
    leftEdge = ltr ? aReflowState.ComputedPhysicalBorderPadding().left
                   : aReflowState.ComputedPhysicalBorderPadding().right;
  }
  nscoord availableWidth = aReflowState.AvailableWidth();
  NS_ASSERTION(availableWidth != NS_UNCONSTRAINEDSIZE,
               "should no longer use available widths");
  // Subtract off left and right border+padding from availableWidth
  availableWidth -= leftEdge;
  availableWidth -= ltr ? aReflowState.ComputedPhysicalBorderPadding().right
                        : aReflowState.ComputedPhysicalBorderPadding().left;
  lineLayout->BeginSpan(this, &aReflowState, leftEdge,
                        leftEdge + availableWidth, &mBaseline);

  // First reflow our principal children.
  nsIFrame* frame = mFrames.FirstChild();
  bool done = false;
  while (frame) {
    // Check if we should lazily set the child frame's parent pointer.
    if (irs.mSetParentPointer) {
      bool havePrevBlock =
        irs.mLineContainer && irs.mLineContainer->GetPrevContinuation();
      nsIFrame* child = frame;
      do {
        // If our block is the first in flow, then any floats under the pulled
        // frame must already belong to our block.
        if (havePrevBlock) {
          // This has to happen before we update frame's parent; we need to
          // know frame's ancestry under its old block.
          // The blockChildren.ContainsFrame check performed by
          // ReparentFloatsForInlineChild here may be slow, but we can't
          // easily avoid it because we don't know where 'frame' originally
          // came from. If we really really have to optimize this we could
          // cache whether frame->GetParent() is under its containing blocks
          // overflowList or not.
          ReparentFloatsForInlineChild(irs.mLineContainer, child, false);
        }
        child->SetParent(this);
        if (inFirstLine) {
          restyleManager->ReparentStyleContext(child);
        }
        // We also need to do the same for |frame|'s next-in-flows that are in
        // the sibling list. Otherwise, if we reflow |frame| and it's complete
        // we'll crash when trying to delete its next-in-flow.
        // This scenario doesn't happen often, but it can happen.
        nsIFrame* nextSibling = child->GetNextSibling();
        child = child->GetNextInFlow();
        if (MOZ_UNLIKELY(child)) {
          while (child != nextSibling && nextSibling) {
            nextSibling = nextSibling->GetNextSibling();
          }
          if (!nextSibling) {
            child = nullptr;
          }
        }
        MOZ_ASSERT(!child || mFrames.ContainsFrame(child));
      } while (child);

      // Fix the parent pointer for ::first-letter child frame next-in-flows,
      // so nsFirstLetterFrame::Reflow can destroy them safely (bug 401042).
      nsIFrame* realFrame = nsPlaceholderFrame::GetRealFrameFor(frame);
      if (realFrame->GetType() == nsGkAtoms::letterFrame) {
        nsIFrame* child = realFrame->GetFirstPrincipalChild();
        if (child) {
          NS_ASSERTION(child->GetType() == nsGkAtoms::textFrame,
                       "unexpected frame type");
          nsIFrame* nextInFlow = child->GetNextInFlow();
          for ( ; nextInFlow; nextInFlow = nextInFlow->GetNextInFlow()) {
            NS_ASSERTION(nextInFlow->GetType() == nsGkAtoms::textFrame,
                         "unexpected frame type");
            if (mFrames.ContainsFrame(nextInFlow)) {
              nextInFlow->SetParent(this);
              if (inFirstLine) {
                restyleManager->ReparentStyleContext(nextInFlow);
              }
            }
            else {
#ifdef DEBUG              
              // Once we find a next-in-flow that isn't ours none of the
              // remaining next-in-flows should be either.
              for ( ; nextInFlow; nextInFlow = nextInFlow->GetNextInFlow()) {
                NS_ASSERTION(!mFrames.ContainsFrame(nextInFlow),
                             "unexpected letter frame flow");
              }
#endif
              break;
            }
          }
        }
      }
    }
    MOZ_ASSERT(frame->GetParent() == this);

    if (!done) {
      bool reflowingFirstLetter = lineLayout->GetFirstLetterStyleOK();
      rv = ReflowInlineFrame(aPresContext, aReflowState, irs, frame, aStatus);
      done = NS_FAILED(rv) ||
             NS_INLINE_IS_BREAK(aStatus) || 
             (!reflowingFirstLetter && NS_FRAME_IS_NOT_COMPLETE(aStatus));
      if (done) {
        if (!irs.mSetParentPointer) {
          break;
        }
        // Keep reparenting the remaining siblings, but don't reflow them.
        nsFrameList* pushedFrames = GetOverflowFrames();
        if (pushedFrames && pushedFrames->FirstChild() == frame) {
          // Don't bother if |frame| was pushed to our overflow list.
          break;
        }
      } else {
        irs.mPrevFrame = frame;
      }
    }
    frame = frame->GetNextSibling();
  }

  // Attempt to pull frames from our next-in-flow until we can't
  if (!done && GetNextInFlow()) {
    while (true) {
      bool reflowingFirstLetter = lineLayout->GetFirstLetterStyleOK();
      bool isComplete;
      if (!frame) { // Could be non-null if we pulled a first-letter frame and
                    // it created a continuation, since we don't push those.
        frame = PullOneFrame(aPresContext, irs, &isComplete);
      }
#ifdef NOISY_PUSHING
      printf("%p pulled up %p\n", this, frame);
#endif
      if (nullptr == frame) {
        if (!isComplete) {
          aStatus = NS_FRAME_NOT_COMPLETE;
        }
        break;
      }
      rv = ReflowInlineFrame(aPresContext, aReflowState, irs, frame, aStatus);
      if (NS_FAILED(rv) ||
          NS_INLINE_IS_BREAK(aStatus) || 
          (!reflowingFirstLetter && NS_FRAME_IS_NOT_COMPLETE(aStatus))) {
        break;
      }
      irs.mPrevFrame = frame;
      frame = frame->GetNextSibling();
    }
  }

  NS_ASSERTION(!NS_FRAME_IS_COMPLETE(aStatus) || !GetOverflowFrames(),
               "We can't be complete AND have overflow frames!");

  // If after reflowing our children they take up no area then make
  // sure that we don't either.
  //
  // Note: CSS demands that empty inline elements still affect the
  // line-height calculations. However, continuations of an inline
  // that are empty we force to empty so that things like collapsed
  // whitespace in an inline element don't affect the line-height.
  aMetrics.Width() = lineLayout->EndSpan(this);

  // Compute final width.

  // Make sure to not include our start border and padding if we have a prev
  // continuation or if we're in a part of an {ib} split other than the first
  // one.
  if (!GetPrevContinuation() && !FrameIsNonFirstInIBSplit()) {
    aMetrics.Width() += ltr ? aReflowState.ComputedPhysicalBorderPadding().left
                          : aReflowState.ComputedPhysicalBorderPadding().right;
  }

  /*
   * We want to only apply the end border and padding if we're the last
   * continuation and either not in an {ib} split or the last part of it.  To
   * be the last continuation we have to be complete (so that we won't get a
   * next-in-flow) and have no non-fluid continuations on our continuation
   * chain.
   */
  if (NS_FRAME_IS_COMPLETE(aStatus) &&
      !LastInFlow()->GetNextContinuation() &&
      !FrameIsNonLastInIBSplit()) {
    aMetrics.Width() += ltr ? aReflowState.ComputedPhysicalBorderPadding().right
                          : aReflowState.ComputedPhysicalBorderPadding().left;
  }

  nsRefPtr<nsFontMetrics> fm;
  float inflation = nsLayoutUtils::FontSizeInflationFor(this);
  nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm), inflation);
  aReflowState.rendContext->SetFont(fm);

  if (fm) {
    // Compute final height of the frame.
    //
    // Do things the standard css2 way -- though it's hard to find it
    // in the css2 spec! It's actually found in the css1 spec section
    // 4.4 (you will have to read between the lines to really see
    // it).
    //
    // The height of our box is the sum of our font size plus the top
    // and bottom border and padding. The height of children do not
    // affect our height.
    aMetrics.SetTopAscent(fm->MaxAscent());
    aMetrics.Height() = fm->MaxHeight();
  } else {
    NS_WARNING("Cannot get font metrics - defaulting sizes to 0");
    aMetrics.SetTopAscent(aMetrics.Height() = 0);
  }
  aMetrics.SetTopAscent(aMetrics.TopAscent() + aReflowState.ComputedPhysicalBorderPadding().top);
  aMetrics.Height() += aReflowState.ComputedPhysicalBorderPadding().top +
    aReflowState.ComputedPhysicalBorderPadding().bottom;

  // For now our overflow area is zero. The real value will be
  // computed in |nsLineLayout::RelativePositionFrames|.
  aMetrics.mOverflowAreas.Clear();

#ifdef NOISY_FINAL_SIZE
  ListTag(stdout);
  printf(": metrics=%d,%d ascent=%d\n",
         aMetrics.Width(), aMetrics.Height(), aMetrics.TopAscent());
#endif

  return rv;
}