nsresult
nsFloatManager::AddFloat(nsIFrame* aFloatFrame, const LogicalRect& aMarginRect,
                         WritingMode aWM, nscoord aContainerWidth)
{
  NS_ASSERTION(aMarginRect.ISize(aWM) >= 0, "negative inline size!");
  NS_ASSERTION(aMarginRect.BSize(aWM) >= 0, "negative block size!");

  FloatInfo info(aFloatFrame, aWM, aMarginRect + mOffset);

  // Set mLeftBEnd and mRightBEnd.
  if (HasAnyFloats()) {
    FloatInfo &tail = mFloats[mFloats.Length() - 1];
    info.mLeftBEnd = tail.mLeftBEnd;
    info.mRightBEnd = tail.mRightBEnd;
  } else {
    info.mLeftBEnd = nscoord_MIN;
    info.mRightBEnd = nscoord_MIN;
  }
  uint8_t floatStyle = aFloatFrame->StyleDisplay()->mFloats;
  NS_ASSERTION(floatStyle == NS_STYLE_FLOAT_LEFT ||
               floatStyle == NS_STYLE_FLOAT_RIGHT, "unexpected float");
  nscoord& sideBEnd =
    ((floatStyle == NS_STYLE_FLOAT_LEFT) == aWM.IsBidiLTR()) ? info.mLeftBEnd
                                                             : info.mRightBEnd;
  nscoord thisBEnd = info.mRect.BEnd(aWM);
  if (thisBEnd > sideBEnd)
    sideBEnd = thisBEnd;

  if (!mFloats.AppendElement(info))
    return NS_ERROR_OUT_OF_MEMORY;

  return NS_OK;
}

/* virtual */
LogicalSize
nsFieldSetFrame::ComputeSize(nsRenderingContext *aRenderingContext,
                             WritingMode aWM,
                             const LogicalSize& aCBSize,
                             nscoord aAvailableISize,
                             const LogicalSize& aMargin,
                             const LogicalSize& aBorder,
                             const LogicalSize& aPadding,
                             ComputeSizeFlags aFlags)
{
  LogicalSize result =
    nsContainerFrame::ComputeSize(aRenderingContext, aWM,
                                  aCBSize, aAvailableISize,
                                  aMargin, aBorder, aPadding, aFlags);

  // XXX The code below doesn't make sense if the caller's writing mode
  // is orthogonal to this frame's. Not sure yet what should happen then;
  // for now, just bail out.
  if (aWM.IsVertical() != GetWritingMode().IsVertical()) {
    return result;
  }

  // Fieldsets never shrink below their min width.

  // If we're a container for font size inflation, then shrink
  // wrapping inside of us should not apply font size inflation.
  AutoMaybeDisableFontInflation an(this);

  nscoord minISize = GetMinISize(aRenderingContext);
  if (minISize > result.ISize(aWM)) {
    result.ISize(aWM) = minISize;
  }

  return result;
}

nscoord
nsSubDocumentFrame::GetIntrinsicBSize()
{
  // <frame> processing does not use this routine, only <iframe>
  NS_ASSERTION(IsInline(), "Shouldn't have been called");

  if (mContent->IsXULElement()) {
    return 0;
  }

  NS_ASSERTION(ObtainIntrinsicSizeFrame() == nullptr,
               "Intrinsic bsize should come from the embedded document.");

  // Use size of 300px x 150px, for compatibility with IE, and per CSS2.1 draft.
  WritingMode wm = GetWritingMode();
  return nsPresContext::CSSPixelsToAppUnits(wm.IsVertical() ? 300 : 150);
}

void
nsSimplePageSequenceFrame::SetDesiredSize(ReflowOutput& aDesiredSize,
                                          const ReflowInput& aReflowInput,
                                          nscoord aWidth,
                                          nscoord aHeight)
{
  // Aim to fill the whole size of the document, not only so we
  // can act as a background in print preview but also handle overflow
  // in child page frames correctly.
  // Use availableISize so we don't cause a needless horizontal scrollbar.
  WritingMode wm = aReflowInput.GetWritingMode();
  nscoord scaledWidth = aWidth * PresContext()->GetPrintPreviewScale();
  nscoord scaledHeight = aHeight * PresContext()->GetPrintPreviewScale();

  nscoord scaledISize = (wm.IsVertical() ? scaledHeight : scaledWidth);
  nscoord scaledBSize = (wm.IsVertical() ? scaledWidth : scaledHeight);

  aDesiredSize.ISize(wm) = std::max(scaledISize, aReflowInput.AvailableISize());
  aDesiredSize.BSize(wm) = std::max(scaledBSize, aReflowInput.ComputedBSize());
}

/* virtual */ nscoord
nsSVGOuterSVGFrame::GetPrefISize(nsRenderingContext *aRenderingContext)
{
  nscoord result;
  DISPLAY_PREF_WIDTH(this, result);

  SVGSVGElement *svg = static_cast<SVGSVGElement*>(mContent);
  WritingMode wm = GetWritingMode();
  const nsSVGLength2& isize = wm.IsVertical()
    ? svg->mLengthAttributes[SVGSVGElement::ATTR_HEIGHT]
    : svg->mLengthAttributes[SVGSVGElement::ATTR_WIDTH];

  if (isize.IsPercentage()) {
    // It looks like our containing block's isize may depend on our isize. In
    // that case our behavior is undefined according to CSS 2.1 section 10.3.2.
    // As a last resort, we'll fall back to returning zero.
    result = nscoord(0);

    // Returning zero may be unhelpful, however, as it leads to unexpected
    // disappearance of %-sized SVGs in orthogonal contexts, where our
    // containing block wants to shrink-wrap. So let's look for an ancestor
    // with non-zero size in this dimension, and use that as a (somewhat
    // arbitrary) result instead.
    nsIFrame *parent = GetParent();
    while (parent) {
      nscoord parentISize = parent->GetLogicalSize(wm).ISize(wm);
      if (parentISize > 0 && parentISize != NS_UNCONSTRAINEDSIZE) {
        result = parentISize;
        break;
      }
      parent = parent->GetParent();
    }
  } else {
    result = nsPresContext::CSSPixelsToAppUnits(isize.GetAnimValue(svg));
    if (result < 0) {
      result = nscoord(0);
    }
  }

  return result;
}

nscoord
nsSubDocumentFrame::GetIntrinsicISize()
{
  if (!IsInline()) {
    return 0;  // HTML <frame> has no useful intrinsic isize
  }

  if (mContent->IsXULElement()) {
    return 0;  // XUL <iframe> and <browser> have no useful intrinsic isize
  }

  NS_ASSERTION(ObtainIntrinsicSizeFrame() == nullptr,
               "Intrinsic isize should come from the embedded document.");

  // We must be an HTML <iframe>.  Default to size of 300px x 150px, for IE
  // compat (and per CSS2.1 draft).
  // This depends on the applied styles, which the comments in nsLeafFrame.h
  // say it should not, but we know it cannot change during the lifetime of
  // the frame because changing writing-mode leads to frame reconstruction.
  WritingMode wm = GetWritingMode();
  return nsPresContext::CSSPixelsToAppUnits(wm.IsVertical() ? 150 : 300);
}

nscoord
nsFloatManager::ClearFloats(WritingMode aWM, nscoord aBCoord,
                            uint8_t aBreakType, nscoord aContainerWidth,
                            uint32_t aFlags) const
{
  if (!(aFlags & DONT_CLEAR_PUSHED_FLOATS) && ClearContinues(aBreakType)) {
    return nscoord_MAX;
  }
  if (!HasAnyFloats()) {
    return aBCoord;
  }

  LogicalPoint offset = mOffset.ConvertTo(aWM, mWritingMode, 0);
  nscoord blockEnd = aBCoord + offset.B(aWM);

  const FloatInfo &tail = mFloats[mFloats.Length() - 1];
  switch (aBreakType) {
    case NS_STYLE_CLEAR_BOTH:
      blockEnd = std::max(blockEnd, tail.mLeftBEnd);
      blockEnd = std::max(blockEnd, tail.mRightBEnd);
      break;
    case NS_STYLE_CLEAR_LEFT:
      blockEnd = std::max(blockEnd, aWM.IsBidiLTR() ? tail.mLeftBEnd
                                                    : tail.mRightBEnd);
      break;
    case NS_STYLE_CLEAR_RIGHT:
      blockEnd = std::max(blockEnd, aWM.IsBidiLTR() ? tail.mRightBEnd
                                                    : tail.mLeftBEnd);
      break;
    default:
      // Do nothing
      break;
  }

  blockEnd -= offset.B(aWM);

  return blockEnd;
}

LogicalSize
nsProgressFrame::ComputeAutoSize(nsRenderingContext *aRenderingContext,
                                 WritingMode aWM,
                                 const LogicalSize& aCBSize,
                                 nscoord aAvailableISize,
                                 const LogicalSize& aMargin,
                                 const LogicalSize& aBorder,
                                 const LogicalSize& aPadding,
                                 bool aShrinkWrap)
{
  const WritingMode wm = GetWritingMode();
  LogicalSize autoSize(wm);
  autoSize.BSize(wm) = autoSize.ISize(wm) =
    NSToCoordRound(StyleFont()->mFont.size *
                   nsLayoutUtils::FontSizeInflationFor(this)); // 1em

  if (ResolvedOrientationIsVertical() == wm.IsVertical()) {
    autoSize.ISize(wm) *= 10; // 10em
  } else {
    autoSize.BSize(wm) *= 10; // 10em
  }

  return autoSize.ConvertTo(aWM, wm);
}

nscoord
nsFormControlFrame::GetLogicalBaseline(WritingMode aWritingMode) const
{
  NS_ASSERTION(!NS_SUBTREE_DIRTY(this),
               "frame must not be dirty");
  // Treat radio buttons and checkboxes as having an intrinsic baseline
  // at the block-end of the control (use the block-end content edge rather
  // than the margin edge).
  // For "inverted" lines (typically in writing-mode:vertical-lr), use the
  // block-start end instead.
  return aWritingMode.IsLineInverted()
    ? GetLogicalUsedBorderAndPadding(aWritingMode).BStart(aWritingMode)
    : BSize(aWritingMode) -
         GetLogicalUsedBorderAndPadding(aWritingMode).BEnd(aWritingMode);
}

nscoord
nsTableWrapperFrame::ChildShrinkWrapISize(nsRenderingContext* aRenderingContext,
                                          nsIFrame*           aChildFrame,
                                          WritingMode         aWM,
                                          LogicalSize         aCBSize,
                                          nscoord             aAvailableISize,
                                          nscoord*            aMarginResult) const
{
  AutoMaybeDisableFontInflation an(aChildFrame);

  // For the caption frame, child's WM may differ from the table's main WM.
  WritingMode childWM = aChildFrame->GetWritingMode();

  SizeComputationInput offsets(aChildFrame, aRenderingContext, aWM,
                               aCBSize.ISize(aWM));
  LogicalSize marginSize =
    offsets.ComputedLogicalMargin().Size(childWM).ConvertTo(aWM, childWM);
  LogicalSize paddingSize =
    offsets.ComputedLogicalPadding().Size(childWM).ConvertTo(aWM, childWM);
  LogicalSize bpSize =
    offsets.ComputedLogicalBorderPadding().Size(childWM).ConvertTo(aWM, childWM);

  // Shrink-wrap aChildFrame by default, except if we're a stretched grid item.
  auto flags = ComputeSizeFlags::eShrinkWrap;
  auto parent = GetParent();
  nsIAtom* parentFrameType = parent ? parent->GetType() : nullptr;
  bool isGridItem = (parentFrameType == nsGkAtoms::gridContainerFrame &&
                     !HasAnyStateBits(NS_FRAME_OUT_OF_FLOW));
  if (MOZ_UNLIKELY(isGridItem) &&
      !StyleMargin()->HasInlineAxisAuto(aWM)) {
    auto inlineAxisAlignment = aWM.IsOrthogonalTo(parent->GetWritingMode()) ?
                     StylePosition()->UsedAlignSelf(parent->StyleContext()) :
                     StylePosition()->UsedJustifySelf(parent->StyleContext());
    if (inlineAxisAlignment == NS_STYLE_ALIGN_NORMAL ||
        inlineAxisAlignment == NS_STYLE_ALIGN_STRETCH) {
      flags = nsIFrame::ComputeSizeFlags::eDefault;
    }
  }

  LogicalSize size =
    aChildFrame->ComputeSize(aRenderingContext, aWM, aCBSize, aAvailableISize,
                             marginSize, bpSize - paddingSize, paddingSize,
                             flags);
  if (aMarginResult) {
    *aMarginResult = offsets.ComputedLogicalMargin().IStartEnd(aWM);
  }
  return size.ISize(aWM) + marginSize.ISize(aWM) + bpSize.ISize(aWM);
}

LogicalSize
nsTextControlFrame::ComputeAutoSize(nsRenderingContext *aRenderingContext,
                                    WritingMode aWM,
                                    const LogicalSize& aCBSize,
                                    nscoord aAvailableISize,
                                    const LogicalSize& aMargin,
                                    const LogicalSize& aBorder,
                                    const LogicalSize& aPadding,
                                    bool aShrinkWrap)
{
  float inflation = nsLayoutUtils::FontSizeInflationFor(this);
  LogicalSize autoSize(aWM);
  nsresult rv = CalcIntrinsicSize(aRenderingContext, aWM, autoSize, inflation);
  if (NS_FAILED(rv)) {
    // What now?
    autoSize.SizeTo(aWM, 0, 0);
  }
#ifdef DEBUG
  // Note: Ancestor ComputeAutoSize only computes a width if we're auto-width
  else {
    const nsStyleCoord& inlineStyleCoord =
      aWM.IsVertical() ? StylePosition()->mHeight : StylePosition()->mWidth;
    if (inlineStyleCoord.GetUnit() == eStyleUnit_Auto) {
      LogicalSize ancestorAutoSize =
        nsContainerFrame::ComputeAutoSize(aRenderingContext, aWM,
                                          aCBSize, aAvailableISize,
                                          aMargin, aBorder,
                                          aPadding, aShrinkWrap);
      // Disabled when there's inflation; see comment in GetPrefSize.
      MOZ_ASSERT(inflation != 1.0f ||
                 ancestorAutoSize.ISize(aWM) == autoSize.ISize(aWM),
                 "Incorrect size computed by ComputeAutoSize?");
    }
  }
#endif

  return autoSize;
}

bool
nsColumnSetFrame::ReflowChildren(ReflowOutput&     aDesiredSize,
                                 const ReflowInput& aReflowInput,
                                 nsReflowStatus&          aStatus,
                                 const ReflowConfig&      aConfig,
                                 bool                     aUnboundedLastColumn,
                                 nsCollapsingMargin*      aCarriedOutBEndMargin,
                                 ColumnBalanceData&       aColData)
{
  aColData.Reset();
  bool allFit = true;
  WritingMode wm = GetWritingMode();
  bool isVertical = wm.IsVertical();
  bool isRTL = !wm.IsBidiLTR();
  bool shrinkingBSizeOnly = !NS_SUBTREE_DIRTY(this) &&
    mLastBalanceBSize > aConfig.mColMaxBSize;

#ifdef DEBUG_roc
  printf("*** Doing column reflow pass: mLastBalanceBSize=%d, mColMaxBSize=%d, RTL=%d\n"
         "    mBalanceColCount=%d, mColISize=%d, mColGap=%d\n",
         mLastBalanceBSize, aConfig.mColMaxBSize, isRTL, aConfig.mBalanceColCount,
         aConfig.mColISize, aConfig.mColGap);
#endif

  DrainOverflowColumns();

  const bool colBSizeChanged = mLastBalanceBSize != aConfig.mColMaxBSize;

  if (colBSizeChanged) {
    mLastBalanceBSize = aConfig.mColMaxBSize;
    // XXX Seems like this could fire if incremental reflow pushed the column set
    // down so we reflow incrementally with a different available height.
    // We need a way to do an incremental reflow and be sure availableHeight
    // changes are taken account of! Right now I think block frames with absolute
    // children might exit early.
    //NS_ASSERTION(aKidReason != eReflowReason_Incremental,
    //             "incremental reflow should not have changed the balance height");
  }

  // get our border and padding
  LogicalMargin borderPadding = aReflowInput.ComputedLogicalBorderPadding();
  borderPadding.ApplySkipSides(GetLogicalSkipSides(&aReflowInput));

  nsRect contentRect(0, 0, 0, 0);
  nsOverflowAreas overflowRects;

  nsIFrame* child = mFrames.FirstChild();
  LogicalPoint childOrigin(wm, borderPadding.IStart(wm),
                           borderPadding.BStart(wm));
  // In vertical-rl mode, columns will not be correctly placed if the
  // reflowInput's ComputedWidth() is UNCONSTRAINED (in which case we'll get
  // a containerSize.width of zero here). In that case, the column positions
  // will be adjusted later, after our correct contentSize is known.
  nsSize containerSize = aReflowInput.ComputedSizeAsContainerIfConstrained();

  // For RTL, since the columns might not fill the frame exactly, we
  // need to account for the slop. Otherwise we'll waste time moving the
  // columns by some tiny amount

  // XXX when all of layout is converted to logical coordinates, we
  //     probably won't need to do this hack any more. For now, we
  //     confine it to the legacy horizontal-rl case
  if (!isVertical && isRTL) {
    nscoord availISize = aReflowInput.AvailableISize();
    if (aReflowInput.ComputedISize() != NS_INTRINSICSIZE) {
      availISize = aReflowInput.ComputedISize();
    }
    if (availISize != NS_INTRINSICSIZE) {
      childOrigin.I(wm) = containerSize.width - borderPadding.Left(wm) -
                          availISize;
#ifdef DEBUG_roc
      printf("*** childOrigin.iCoord = %d\n", childOrigin.I(wm));
#endif
    }
  }

  int columnCount = 0;
  int contentBEnd = 0;
  bool reflowNext = false;

  while (child) {
    // Try to skip reflowing the child. We can't skip if the child is dirty. We also can't
    // skip if the next column is dirty, because the next column's first line(s)
    // might be pullable back to this column. We can't skip if it's the last child
    // because we need to obtain the bottom margin. We can't skip
    // if this is the last column and we're supposed to assign unbounded
    // height to it, because that could change the available height from
    // the last time we reflowed it and we should try to pull all the
    // content from its next sibling. (Note that it might be the last
    // column, but not be the last child because the desired number of columns
    // has changed.)
    bool skipIncremental = !aReflowInput.ShouldReflowAllKids()
      && !NS_SUBTREE_DIRTY(child)
      && child->GetNextSibling()
      && !(aUnboundedLastColumn && columnCount == aConfig.mBalanceColCount - 1)
      && !NS_SUBTREE_DIRTY(child->GetNextSibling());
    // If we need to pull up content from the prev-in-flow then this is not just
    // a height shrink. The prev in flow will have set the dirty bit.
    // Check the overflow rect YMost instead of just the child's content height. The child
    // may have overflowing content that cares about the available height boundary.
//.........这里部分代码省略.........

bool
nsAbsoluteContainingBlock::FrameDependsOnContainer(nsIFrame* f,
                                                   bool aCBWidthChanged,
                                                   bool aCBHeightChanged)
{
  const nsStylePosition* pos = f->StylePosition();
  // See if f's position might have changed because it depends on a
  // placeholder's position
  // This can happen in the following cases:
  // 1) Vertical positioning.  "top" must be auto and "bottom" must be auto
  //    (otherwise the vertical position is completely determined by
  //    whichever of them is not auto and the height).
  // 2) Horizontal positioning.  "left" must be auto and "right" must be auto
  //    (otherwise the horizontal position is completely determined by
  //    whichever of them is not auto and the width).
  // See nsHTMLReflowState::InitAbsoluteConstraints -- these are the
  // only cases when we call CalculateHypotheticalBox().
  if ((pos->mOffset.GetTopUnit() == eStyleUnit_Auto &&
       pos->mOffset.GetBottomUnit() == eStyleUnit_Auto) ||
      (pos->mOffset.GetLeftUnit() == eStyleUnit_Auto &&
       pos->mOffset.GetRightUnit() == eStyleUnit_Auto)) {
    return true;
  }
  if (!aCBWidthChanged && !aCBHeightChanged) {
    // skip getting style data
    return false;
  }
  const nsStylePadding* padding = f->StylePadding();
  const nsStyleMargin* margin = f->StyleMargin();
  WritingMode wm = f->GetWritingMode();
  if (wm.IsVertical() ? aCBHeightChanged : aCBWidthChanged) {
    // See if f's inline-size might have changed.
    // If margin-inline-start/end, padding-inline-start/end,
    // inline-size, min/max-inline-size are all lengths, 'none', or enumerated,
    // then our frame isize does not depend on the parent isize.
    // Note that borders never depend on the parent isize.
    // XXX All of the enumerated values except -moz-available are ok too.
    if (pos->ISizeDependsOnContainer(wm) ||
        pos->MinISizeDependsOnContainer(wm) ||
        pos->MaxISizeDependsOnContainer(wm) ||
        !IsFixedPaddingSize(padding->mPadding.GetIStart(wm)) ||
        !IsFixedPaddingSize(padding->mPadding.GetIEnd(wm))) {
      return true;
    }

    // See if f's position might have changed. If we're RTL then the
    // rules are slightly different. We'll assume percentage or auto
    // margins will always induce a dependency on the size
    if (!IsFixedMarginSize(margin->mMargin.GetIStart(wm)) ||
        !IsFixedMarginSize(margin->mMargin.GetIEnd(wm))) {
      return true;
    }
    if (!wm.IsBidiLTR()) {
      // Note that even if 'istart' is a length, our position can
      // still depend on the containing block isze, because if
      // 'iend' is also a length we will discard 'istart' and be
      // positioned relative to the containing block iend edge.
      // 'istart' length and 'iend' auto is the only combination
      // we can be sure of.
      if (!IsFixedOffset(pos->mOffset.GetIStart(wm)) ||
          pos->mOffset.GetIEndUnit(wm) != eStyleUnit_Auto) {
        return true;
      }
    } else {
      if (!IsFixedOffset(pos->mOffset.GetIStart(wm))) {
        return true;
      }
    }
  }
  if (wm.IsVertical() ? aCBWidthChanged : aCBHeightChanged) {
    // See if f's block-size might have changed.
    // If margin-block-start/end, padding-block-start/end,
    // min-block-size, and max-block-size are all lengths or 'none',
    // and bsize is a length or bsize and bend are auto and bstart is not auto,
    // then our frame bsize does not depend on the parent bsize.
    // Note that borders never depend on the parent bsize.
    if ((pos->BSizeDependsOnContainer(wm) &&
         !(pos->BSize(wm).GetUnit() == eStyleUnit_Auto &&
           pos->mOffset.GetBEndUnit(wm) == eStyleUnit_Auto &&
           pos->mOffset.GetBStartUnit(wm) != eStyleUnit_Auto)) ||
        pos->MinBSizeDependsOnContainer(wm) ||
        pos->MaxBSizeDependsOnContainer(wm) ||
        !IsFixedPaddingSize(padding->mPadding.GetBStart(wm)) ||
        !IsFixedPaddingSize(padding->mPadding.GetBEnd(wm))) {
      return true;
    }
      
    // See if f's position might have changed.
    if (!IsFixedMarginSize(margin->mMargin.GetBStart(wm)) ||
        !IsFixedMarginSize(margin->mMargin.GetBEnd(wm))) {
      return true;
    }
    if (!IsFixedOffset(pos->mOffset.GetBStart(wm))) {
      return true;
    }
  }
  return false;
}

void
nsProgressFrame::ReflowBarFrame(nsIFrame*                aBarFrame,
                                nsPresContext*           aPresContext,
                                const nsHTMLReflowState& aReflowState,
                                nsReflowStatus&          aStatus)
{
  bool vertical = ResolvedOrientationIsVertical();
  WritingMode wm = aBarFrame->GetWritingMode();
  LogicalSize availSize = aReflowState.ComputedSize(wm);
  availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
  nsHTMLReflowState reflowState(aPresContext, aReflowState,
                                aBarFrame, availSize);
  nscoord size = vertical ? aReflowState.ComputedHeight()
                          : aReflowState.ComputedWidth();
  nscoord xoffset = aReflowState.ComputedPhysicalBorderPadding().left;
  nscoord yoffset = aReflowState.ComputedPhysicalBorderPadding().top;

  double position = static_cast<HTMLProgressElement*>(mContent)->Position();

  // Force the bar's size to match the current progress.
  // When indeterminate, the progress' size will be 100%.
  if (position >= 0.0) {
    size *= position;
  }

  if (!vertical && (wm.IsVertical() ? wm.IsVerticalRL() : !wm.IsBidiLTR())) {
    xoffset += aReflowState.ComputedWidth() - size;
  }

  // The bar size is fixed in these cases:
  // - the progress position is determined: the bar size is fixed according
  //   to it's value.
  // - the progress position is indeterminate and the bar appearance should be
  //   shown as native: the bar size is forced to 100%.
  // Otherwise (when the progress is indeterminate and the bar appearance isn't
  // native), the bar size isn't fixed and can be set by the author.
  if (position != -1 || ShouldUseNativeStyle()) {
    if (vertical) {
      // We want the bar to begin at the bottom.
      yoffset += aReflowState.ComputedHeight() - size;

      size -= reflowState.ComputedPhysicalMargin().TopBottom() +
              reflowState.ComputedPhysicalBorderPadding().TopBottom();
      size = std::max(size, 0);
      reflowState.SetComputedHeight(size);
    } else {
      size -= reflowState.ComputedPhysicalMargin().LeftRight() +
              reflowState.ComputedPhysicalBorderPadding().LeftRight();
      size = std::max(size, 0);
      reflowState.SetComputedWidth(size);
    }
  } else if (vertical) {
    // For vertical progress bars, we need to position the bar specificly when
    // the width isn't constrained (position == -1 and !ShouldUseNativeStyle())
    // because aReflowState.ComputedHeight() - size == 0.
    yoffset += aReflowState.ComputedHeight() - reflowState.ComputedHeight();
  }

  xoffset += reflowState.ComputedPhysicalMargin().left;
  yoffset += reflowState.ComputedPhysicalMargin().top;

  nsHTMLReflowMetrics barDesiredSize(aReflowState);
  ReflowChild(aBarFrame, aPresContext, barDesiredSize, reflowState, xoffset,
              yoffset, 0, aStatus);
  FinishReflowChild(aBarFrame, aPresContext, barDesiredSize, &reflowState,
                    xoffset, yoffset, 0);
}

void
nsRubyFrame::ReflowSegment(nsPresContext* aPresContext,
                           const ReflowInput& aReflowInput,
                           nsRubyBaseContainerFrame* aBaseContainer,
                           nsReflowStatus& aStatus)
{
  WritingMode lineWM = aReflowInput.mLineLayout->GetWritingMode();
  LogicalSize availSize(lineWM, aReflowInput.AvailableISize(),
                        aReflowInput.AvailableBSize());
  WritingMode rubyWM = GetWritingMode();
  NS_ASSERTION(!rubyWM.IsOrthogonalTo(lineWM),
               "Ruby frame writing-mode shouldn't be orthogonal to its line");

  AutoRubyTextContainerArray textContainers(aBaseContainer);
  const uint32_t rtcCount = textContainers.Length();

  ReflowOutput baseMetrics(aReflowInput);
  bool pushedFrame;
  aReflowInput.mLineLayout->ReflowFrame(aBaseContainer, aStatus,
                                        &baseMetrics, pushedFrame);

  if (NS_INLINE_IS_BREAK_BEFORE(aStatus)) {
    if (aBaseContainer != mFrames.FirstChild()) {
      // Some segments may have been reflowed before, hence it is not
      // a break-before for the ruby container.
      aStatus = NS_INLINE_LINE_BREAK_AFTER(NS_FRAME_NOT_COMPLETE);
      PushChildren(aBaseContainer, aBaseContainer->GetPrevSibling());
      aReflowInput.mLineLayout->SetDirtyNextLine();
    }
    // This base container is not placed at all, we can skip all
    // text containers paired with it.
    return;
  }
  if (NS_FRAME_IS_NOT_COMPLETE(aStatus)) {
    // It always promise that if the status is incomplete, there is a
    // break occurs. Break before has been processed above. However,
    // it is possible that break after happens with the frame reflow
    // completed. It happens if there is a force break at the end.
    MOZ_ASSERT(NS_INLINE_IS_BREAK_AFTER(aStatus));
    // Find the previous sibling which we will
    // insert new continuations after.
    nsIFrame* lastChild;
    if (rtcCount > 0) {
      lastChild = textContainers.LastElement();
    } else {
      lastChild = aBaseContainer;
    }

    // Create continuations for the base container
    nsIFrame* newBaseContainer = CreateNextInFlow(aBaseContainer);
    // newBaseContainer is null if there are existing next-in-flows.
    // We only need to move and push if there were not.
    if (newBaseContainer) {
      // Move the new frame after all the text containers
      mFrames.RemoveFrame(newBaseContainer);
      mFrames.InsertFrame(nullptr, lastChild, newBaseContainer);

      // Create continuations for text containers
      nsIFrame* newLastChild = newBaseContainer;
      for (uint32_t i = 0; i < rtcCount; i++) {
        nsIFrame* newTextContainer = CreateNextInFlow(textContainers[i]);
        MOZ_ASSERT(newTextContainer, "Next-in-flow of rtc should not exist "
                   "if the corresponding rbc does not");
        mFrames.RemoveFrame(newTextContainer);
        mFrames.InsertFrame(nullptr, newLastChild, newTextContainer);
        newLastChild = newTextContainer;
      }
    }
    if (lastChild != mFrames.LastChild()) {
      // Always push the next frame after the last child in this segment.
      // It is possible that we pulled it back before our next-in-flow
      // drain our overflow.
      PushChildren(lastChild->GetNextSibling(), lastChild);
      aReflowInput.mLineLayout->SetDirtyNextLine();
    }
  } else {
    // If the ruby base container is reflowed completely, the line
    // layout will remove the next-in-flows of that frame. But the
    // line layout is not aware of the ruby text containers, hence
    // it is necessary to remove them here.
    for (uint32_t i = 0; i < rtcCount; i++) {
      nsIFrame* nextRTC = textContainers[i]->GetNextInFlow();
      if (nextRTC) {
        nextRTC->GetParent()->DeleteNextInFlowChild(nextRTC, true);
      }
    }
  }

  nscoord segmentISize = baseMetrics.ISize(lineWM);
  const nsSize dummyContainerSize;
  LogicalRect baseRect =
    aBaseContainer->GetLogicalRect(lineWM, dummyContainerSize);
  // We need to position our rtc frames on one side or the other of the
  // base container's rect, using a coordinate space that's relative to
  // the ruby frame. Right now, the base container's rect's block-axis
  // position is relative to the block container frame containing the
  // lines, so we use 0 instead. (i.e. we assume that the base container
  // is adjacent to the ruby frame's block-start edge.)
  // XXX We may need to add border/padding here. See bug 1055667.
  baseRect.BStart(lineWM) = 0;
//.........这里部分代码省略.........

nsFlowAreaRect
nsFloatManager::GetFlowArea(WritingMode aWM, nscoord aBOffset,
                            BandInfoType aInfoType, nscoord aBSize,
                            LogicalRect aContentArea, SavedState* aState,
                            nscoord aContainerWidth) const
{
  NS_ASSERTION(aBSize >= 0, "unexpected max block size");
  NS_ASSERTION(aContentArea.ISize(aWM) >= 0,
               "unexpected content area inline size");

  LogicalPoint offset = mOffset.ConvertTo(aWM, mWritingMode, 0);
  nscoord blockStart = aBOffset + offset.B(aWM);
  if (blockStart < nscoord_MIN) {
    NS_WARNING("bad value");
    blockStart = nscoord_MIN;
  }

  // Determine the last float that we should consider.
  uint32_t floatCount;
  if (aState) {
    // Use the provided state.
    floatCount = aState->mFloatInfoCount;
    NS_ABORT_IF_FALSE(floatCount <= mFloats.Length(), "bad state");
  } else {
    // Use our current state.
    floatCount = mFloats.Length();
  }

  // If there are no floats at all, or we're below the last one, return
  // quickly.
  if (floatCount == 0 ||
      (mFloats[floatCount-1].mLeftBEnd <= blockStart &&
       mFloats[floatCount-1].mRightBEnd <= blockStart)) {
    return nsFlowAreaRect(aWM, aContentArea.IStart(aWM), aBOffset,
                          aContentArea.ISize(aWM), aBSize, false);
  }

  nscoord blockEnd;
  if (aBSize == nscoord_MAX) {
    // This warning (and the two below) are possible to hit on pages
    // with really large objects.
    NS_WARN_IF_FALSE(aInfoType == BAND_FROM_POINT,
                     "bad height");
    blockEnd = nscoord_MAX;
  } else {
    blockEnd = blockStart + aBSize;
    if (blockEnd < blockStart || blockEnd > nscoord_MAX) {
      NS_WARNING("bad value");
      blockEnd = nscoord_MAX;
    }
  }
  nscoord inlineStart = offset.I(aWM) + aContentArea.IStart(aWM);
  nscoord inlineEnd = offset.I(aWM) + aContentArea.IEnd(aWM);
  if (inlineEnd < inlineStart) {
    NS_WARNING("bad value");
    inlineEnd = inlineStart;
  }

  // Walk backwards through the floats until we either hit the front of
  // the list or we're above |blockStart|.
  bool haveFloats = false;
  for (uint32_t i = floatCount; i > 0; --i) {
    const FloatInfo &fi = mFloats[i-1];
    if (fi.mLeftBEnd <= blockStart && fi.mRightBEnd <= blockStart) {
      // There aren't any more floats that could intersect this band.
      break;
    }
    if (fi.mRect.IsEmpty()) {
      // For compatibility, ignore floats with empty rects, even though it
      // disagrees with the spec.  (We might want to fix this in the
      // future, though.)
      continue;
    }

    LogicalRect rect = fi.mRect.ConvertTo(aWM, fi.mWritingMode,
                                          aContainerWidth);
    nscoord floatBStart = rect.BStart(aWM);
    nscoord floatBEnd = rect.BEnd(aWM);
    if (blockStart < floatBStart && aInfoType == BAND_FROM_POINT) {
      // This float is below our band.  Shrink our band's height if needed.
      if (floatBStart < blockEnd) {
        blockEnd = floatBStart;
      }
    }
    // If blockStart == blockEnd (which happens only with WIDTH_WITHIN_HEIGHT),
    // we include floats that begin at our 0-height vertical area.  We
    // need to to this to satisfy the invariant that a
    // WIDTH_WITHIN_HEIGHT call is at least as narrow on both sides as a
    // BAND_WITHIN_POINT call beginning at its blockStart.
    else if (blockStart < floatBEnd &&
             (floatBStart < blockEnd ||
              (floatBStart == blockEnd && blockStart == blockEnd))) {
      // This float is in our band.

      // Shrink our band's height if needed.
      if (floatBEnd < blockEnd && aInfoType == BAND_FROM_POINT) {
        blockEnd = floatBEnd;
      }

      // Shrink our band's width if needed.
//.........这里部分代码省略.........

void
nsFieldSetFrame::Reflow(nsPresContext*           aPresContext,
                        nsHTMLReflowMetrics&     aDesiredSize,
                        const nsHTMLReflowState& aReflowState,
                        nsReflowStatus&          aStatus)
{
  MarkInReflow();
  DO_GLOBAL_REFLOW_COUNT("nsFieldSetFrame");
  DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);

  NS_PRECONDITION(aReflowState.ComputedISize() != NS_INTRINSICSIZE,
                  "Should have a precomputed inline-size!");

  // Initialize OUT parameter
  aStatus = NS_FRAME_COMPLETE;

  nsOverflowAreas ocBounds;
  nsReflowStatus ocStatus = NS_FRAME_COMPLETE;
  if (GetPrevInFlow()) {
    ReflowOverflowContainerChildren(aPresContext, aReflowState, ocBounds, 0,
                                    ocStatus);
  }

  //------------ Handle Incremental Reflow -----------------
  bool reflowInner;
  bool reflowLegend;
  nsIFrame* legend = GetLegend();
  nsIFrame* inner = GetInner();
  if (aReflowState.ShouldReflowAllKids()) {
    reflowInner = inner != nullptr;
    reflowLegend = legend != nullptr;
  } else {
    reflowInner = inner && NS_SUBTREE_DIRTY(inner);
    reflowLegend = legend && NS_SUBTREE_DIRTY(legend);
  }

  // We don't allow fieldsets to break vertically. If we did, we'd
  // need logic here to push and pull overflow frames.
  // Since we're not applying our padding in this frame, we need to add it here
  // to compute the available width for our children.
  WritingMode wm = GetWritingMode();
  WritingMode innerWM = inner ? inner->GetWritingMode() : wm;
  WritingMode legendWM = legend ? legend->GetWritingMode() : wm;
  LogicalSize innerAvailSize = aReflowState.ComputedSizeWithPadding(innerWM);
  LogicalSize legendAvailSize = aReflowState.ComputedSizeWithPadding(legendWM);
  innerAvailSize.BSize(innerWM) = legendAvailSize.BSize(legendWM) =
    NS_UNCONSTRAINEDSIZE;
  NS_ASSERTION(!inner ||
      nsLayoutUtils::IntrinsicForContainer(aReflowState.rendContext,
                                           inner,
                                           nsLayoutUtils::MIN_ISIZE) <=
               innerAvailSize.ISize(innerWM),
               "Bogus availSize.ISize; should be bigger");
  NS_ASSERTION(!legend ||
      nsLayoutUtils::IntrinsicForContainer(aReflowState.rendContext,
                                           legend,
                                           nsLayoutUtils::MIN_ISIZE) <=
               legendAvailSize.ISize(legendWM),
               "Bogus availSize.ISize; should be bigger");

  // get our border and padding
  LogicalMargin border = aReflowState.ComputedLogicalBorderPadding() -
                         aReflowState.ComputedLogicalPadding();

  // Figure out how big the legend is if there is one.
  // get the legend's margin
  LogicalMargin legendMargin(wm);
  // reflow the legend only if needed
  Maybe<nsHTMLReflowState> legendReflowState;
  if (legend) {
    legendReflowState.emplace(aPresContext, aReflowState, legend,
                                legendAvailSize);
  }
  if (reflowLegend) {
    nsHTMLReflowMetrics legendDesiredSize(aReflowState);

    // We'll move the legend to its proper place later, so the position
    // and containerSize passed here are unimportant.
    const nsSize dummyContainerSize;
    ReflowChild(legend, aPresContext, legendDesiredSize, *legendReflowState,
                wm, LogicalPoint(wm), dummyContainerSize,
                NS_FRAME_NO_MOVE_FRAME, aStatus);
#ifdef NOISY_REFLOW
    printf("  returned (%d, %d)\n",
           legendDesiredSize.Width(), legendDesiredSize.Height());
#endif
    // figure out the legend's rectangle
    legendMargin = legend->GetLogicalUsedMargin(wm);
    mLegendRect =
      LogicalRect(wm, 0, 0,
                  legendDesiredSize.ISize(wm) + legendMargin.IStartEnd(wm),
                  legendDesiredSize.BSize(wm) + legendMargin.BStartEnd(wm));
    nscoord oldSpace = mLegendSpace;
    mLegendSpace = 0;
    if (mLegendRect.BSize(wm) > border.BStart(wm)) {
      // center the border on the legend
      mLegendSpace = mLegendRect.BSize(wm) - border.BStart(wm);
    } else {
      mLegendRect.BStart(wm) =
        (border.BStart(wm) - mLegendRect.BSize(wm)) / 2;
//.........这里部分代码省略.........

void
BRFrame::Reflow(nsPresContext* aPresContext,
                ReflowOutput& aMetrics,
                const ReflowInput& aReflowInput,
                nsReflowStatus& aStatus)
{
  MarkInReflow();
  DO_GLOBAL_REFLOW_COUNT("BRFrame");
  DISPLAY_REFLOW(aPresContext, this, aReflowInput, aMetrics, aStatus);
  WritingMode wm = aReflowInput.GetWritingMode();
  LogicalSize finalSize(wm);
  finalSize.BSize(wm) = 0; // BR frames with block size 0 are ignored in quirks
                           // mode by nsLineLayout::VerticalAlignFrames .
                           // However, it's not always 0.