C++ WritingMode::IsBidiLTR方法代码示例

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;
}

LogicalRect
nsFloatManager::CalculateRegionFor(WritingMode          aWM,
                                   nsIFrame*            aFloat,
                                   const LogicalMargin& aMargin,
                                   nscoord              aContainerWidth)
{
  // We consider relatively positioned frames at their original position.
  LogicalRect region(aWM, nsRect(aFloat->GetNormalPosition(),
                                 aFloat->GetSize()),
                     aContainerWidth);

  // Float region includes its margin
  region.Inflate(aWM, aMargin);

  // Don't store rectangles with negative margin-box width or height in
  // the float manager; it can't deal with them.
  if (region.ISize(aWM) < 0) {
    // Preserve the right margin-edge for left floats and the left
    // margin-edge for right floats
    const nsStyleDisplay* display = aFloat->StyleDisplay();
    if ((NS_STYLE_FLOAT_LEFT == display->mFloats) == aWM.IsBidiLTR()) {
      region.IStart(aWM) = region.IEnd(aWM);
    }
    region.ISize(aWM) = 0;
  }
  if (region.BSize(aWM) < 0) {
    region.BSize(aWM) = 0;
  }
  return region;
}

void
nsMeterFrame::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;

  // NOTE: Introduce a new function getPosition in the content part ?
  HTMLMeterElement* meterElement = static_cast<HTMLMeterElement*>(mContent);

  double max = meterElement->Max();
  double min = meterElement->Min();
  double value = meterElement->Value();

  double position = max - min;
  position = position != 0 ? (value - min) / position : 1;

  size = NSToCoordRound(size * position);

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

  // The bar position is *always* constrained.
  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);
  }

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

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

bool
nsNativeTheme::IsFrameRTL(nsIFrame* aFrame)
{
  if (!aFrame) {
    return false;
  }
  WritingMode wm = aFrame->GetWritingMode();
  return !(wm.IsVertical() ? wm.IsVerticalLR() : wm.IsBidiLTR());
}

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;
}

//.........这里部分代码省略.........
  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.
      if ((fi.mFrame->StyleDisplay()->mFloats == NS_STYLE_FLOAT_LEFT) ==
          aWM.IsBidiLTR()) {
        // A left float in an ltr block or a right float in an rtl block
        nscoord inlineEndEdge = rect.IEnd(aWM);
        if (inlineEndEdge > inlineStart) {
          inlineStart = inlineEndEdge;
          // Only set haveFloats to true if the float is inside our
          // containing block.  This matches the spec for what some
          // callers want and disagrees for other callers, so we should
          // probably provide better information at some point.
          haveFloats = true;
        }
      } else {
        // A left float in an rtl block or a right float in an ltr block
        nscoord inlineStartEdge = rect.IStart(aWM);
        if (inlineStartEdge < inlineEnd) {
          inlineEnd = inlineStartEdge;
          // See above.
          haveFloats = true;
        }
      }
    }
  }

  nscoord blockSize = (blockEnd == nscoord_MAX) ?
                       nscoord_MAX : (blockEnd - blockStart);
  return nsFlowAreaRect(aWM,
                        inlineStart - offset.I(aWM), blockStart - offset.B(aWM),
                        inlineEnd - inlineStart, blockSize, haveFloats);
}

//.........这里部分代码省略.........
    FinishReflowChild(inner, aPresContext, kidDesiredSize,
                      &kidReflowState, wm, pt, containerSize, 0);
    NS_FRAME_TRACE_REFLOW_OUT("FieldSet::Reflow", aStatus);
  } else if (inner) {
    // |inner| didn't need to be reflowed but we do need to include its size
    // in containerSize.
    containerSize += inner->GetSize();
  }

  LogicalRect contentRect(wm);
  if (inner) {
    // We don't support margins on inner, so our content rect is just the
    // inner's border-box. (We don't really care about container size at this
    // point, as we'll figure out the actual positioning later.)
    contentRect = inner->GetLogicalRect(wm, containerSize);
  }

  // Our content rect must fill up the available width
  LogicalSize availSize = aReflowState.ComputedSizeWithPadding(wm);
  if (availSize.ISize(wm) > contentRect.ISize(wm)) {
    contentRect.ISize(wm) = innerAvailSize.ISize(wm);
  }

  if (legend) {
    // The legend is positioned inline-wards within the inner's content rect
    // (so that padding on the fieldset affects the legend position).
    LogicalRect innerContentRect = contentRect;
    innerContentRect.Deflate(wm, aReflowState.ComputedLogicalPadding());
    // If the inner content rect is larger than the legend, we can align the
    // legend.
    if (innerContentRect.ISize(wm) > mLegendRect.ISize(wm)) {
      int32_t align = static_cast<nsLegendFrame*>
        (legend->GetContentInsertionFrame())->GetAlign();
      if (!wm.IsBidiLTR()) {
        if (align == NS_STYLE_TEXT_ALIGN_LEFT ||
            align == NS_STYLE_TEXT_ALIGN_MOZ_LEFT) {
          align = NS_STYLE_TEXT_ALIGN_END;
        } else if (align == NS_STYLE_TEXT_ALIGN_RIGHT ||
                   align == NS_STYLE_TEXT_ALIGN_MOZ_RIGHT) {
          align = NS_STYLE_TEXT_ALIGN_DEFAULT;
        }
      }
      switch (align) {
        case NS_STYLE_TEXT_ALIGN_END:
          mLegendRect.IStart(wm) =
            innerContentRect.IEnd(wm) - mLegendRect.ISize(wm);
          break;
        case NS_STYLE_TEXT_ALIGN_CENTER:
        case NS_STYLE_TEXT_ALIGN_MOZ_CENTER:
          // Note: rounding removed; there doesn't seem to be any need
          mLegendRect.IStart(wm) = innerContentRect.IStart(wm) +
            (innerContentRect.ISize(wm) - mLegendRect.ISize(wm)) / 2;
          break;
        default:
          mLegendRect.IStart(wm) = innerContentRect.IStart(wm);
          break;
      }
    } else {
      // otherwise make place for the legend
      mLegendRect.IStart(wm) = innerContentRect.IStart(wm);
      innerContentRect.ISize(wm) = mLegendRect.ISize(wm);
      contentRect.ISize(wm) = mLegendRect.ISize(wm) +
        aReflowState.ComputedLogicalPadding().IStartEnd(wm);
    }

    // place the legend

nsresult
nsTableWrapperFrame::GetCaptionOrigin(uint32_t             aCaptionSide,
                                      const LogicalSize&   aContainBlockSize,
                                      const LogicalSize&   aInnerSize,
                                      const LogicalMargin& aInnerMargin,
                                      const LogicalSize&   aCaptionSize,
                                      LogicalMargin&       aCaptionMargin,
                                      LogicalPoint&        aOrigin,
                                      WritingMode          aWM)
{
  aOrigin.I(aWM) = aOrigin.B(aWM) = 0;
  if ((NS_UNCONSTRAINEDSIZE == aInnerSize.ISize(aWM)) ||
      (NS_UNCONSTRAINEDSIZE == aInnerSize.BSize(aWM)) ||
      (NS_UNCONSTRAINEDSIZE == aCaptionSize.ISize(aWM)) ||
      (NS_UNCONSTRAINEDSIZE == aCaptionSize.BSize(aWM))) {
    return NS_OK;
  }
  if (mCaptionFrames.IsEmpty()) {
    return NS_OK;
  }
  
  NS_ASSERTION(NS_AUTOMARGIN != aCaptionMargin.IStart(aWM) &&
               NS_AUTOMARGIN != aCaptionMargin.BStart(aWM) &&
               NS_AUTOMARGIN != aCaptionMargin.BEnd(aWM),
               "The computed caption margin is auto?");

  // inline-dir computation
  switch (aCaptionSide) {
    case NS_STYLE_CAPTION_SIDE_BOTTOM:
    case NS_STYLE_CAPTION_SIDE_BOTTOM_OUTSIDE:
      aOrigin.I(aWM) = aCaptionMargin.IStart(aWM);
      if (aCaptionSide == NS_STYLE_CAPTION_SIDE_BOTTOM) {
        // We placed the caption using only the table's isize as available
        // isize, and we should position it this way as well.
        aOrigin.I(aWM) += aInnerMargin.IStart(aWM);
      }
      break;
    case NS_STYLE_CAPTION_SIDE_LEFT:
    case NS_STYLE_CAPTION_SIDE_RIGHT:
      aOrigin.I(aWM) = aCaptionMargin.IStart(aWM);
      if (aWM.IsBidiLTR() == (aCaptionSide == NS_STYLE_CAPTION_SIDE_RIGHT)) {
        aOrigin.I(aWM) += aInnerMargin.IStart(aWM) + aInnerSize.ISize(aWM);
      }
      break;
    default: // block-start
      NS_ASSERTION(aCaptionSide == NS_STYLE_CAPTION_SIDE_TOP ||
                   aCaptionSide == NS_STYLE_CAPTION_SIDE_TOP_OUTSIDE,
                   "unexpected caption side");
      aOrigin.I(aWM) = aCaptionMargin.IStart(aWM);
      if (aCaptionSide == NS_STYLE_CAPTION_SIDE_TOP) {
        // We placed the caption using only the table's isize as available
        // isize, and we should position it this way as well.
        aOrigin.I(aWM) += aInnerMargin.IStart(aWM);
      }
      break;
  }
  // block-dir computation
  switch (aCaptionSide) {
    case NS_STYLE_CAPTION_SIDE_RIGHT:
    case NS_STYLE_CAPTION_SIDE_LEFT:
      aOrigin.B(aWM) = aInnerMargin.BStart(aWM);
      switch (GetCaptionVerticalAlign()) {
        case NS_STYLE_VERTICAL_ALIGN_MIDDLE:
          aOrigin.B(aWM) = std::max(0, aInnerMargin.BStart(aWM) +
                                       ((aInnerSize.BSize(aWM) -
                                         aCaptionSize.BSize(aWM)) / 2));
          break;
        case NS_STYLE_VERTICAL_ALIGN_BOTTOM:
          aOrigin.B(aWM) = std::max(0, aInnerMargin.BStart(aWM) +
                                       aInnerSize.BSize(aWM) -
                                       aCaptionSize.BSize(aWM));
          break;
        default:
          break;
      }
      break;
    case NS_STYLE_CAPTION_SIDE_BOTTOM_OUTSIDE:
    case NS_STYLE_CAPTION_SIDE_BOTTOM:
      aOrigin.B(aWM) = aInnerMargin.BStart(aWM) + aInnerSize.BSize(aWM) +
                       aCaptionMargin.BStart(aWM);
      break;
    case NS_STYLE_CAPTION_SIDE_TOP_OUTSIDE:
    case NS_STYLE_CAPTION_SIDE_TOP:
      aOrigin.B(aWM) = aInnerMargin.BStart(aWM) + aCaptionMargin.BStart(aWM);
      break;
    default:
      NS_NOTREACHED("Unknown caption alignment type");
      break;
  }
  return NS_OK;
}

//.........这里部分代码省略.........
              // since we cannot evangelize the world
              break;
            }
          }
        }
      }

      // the table does not fit anymore in this line so advance to next band 
      mBCoord += floatAvailableSpace.mRect.BSize(wm);
      // To match nsBlockFrame::AdjustFloatAvailableSpace, we have to
      // get a new width for the new band.
      floatAvailableSpace = GetFloatAvailableSpace(mBCoord);
      adjustedAvailableSpace = mBlock->AdjustFloatAvailableSpace(*this,
                                 floatAvailableSpace.mRect, aFloat);
      floatMarginISize = FloatMarginISize(mReflowState,
                                          adjustedAvailableSpace.ISize(wm),
                                          aFloat, offsets);
    }

    mustPlaceFloat = false;
  }

  // If the float is continued, it will get the same absolute x value as its prev-in-flow

  // We don't worry about the geometry of the prev in flow, let the continuation
  // place and size itself as required.

  // Assign inline and block dir coordinates to the float. We don't use
  // LineLeft() and LineRight() here, because we would only have to
  // convert the result back into this block's writing mode.
  LogicalPoint floatPos(wm);
  bool leftFloat = NS_STYLE_FLOAT_LEFT == floatStyle;

  if (leftFloat == wm.IsBidiLTR()) {
    floatPos.I(wm) = floatAvailableSpace.mRect.IStart(wm);
  }
  else {
    if (!keepFloatOnSameLine) {
      floatPos.I(wm) = floatAvailableSpace.mRect.IEnd(wm) - floatMarginISize;
    }
    else {
      // this is the IE quirk (see few lines above)
      // the table is kept in the same line: don't let it overlap the
      // previous float
      floatPos.I(wm) = floatAvailableSpace.mRect.IStart(wm);
    }
  }
  // CSS2 spec, 9.5.1 rule [4]: "A floating box's outer top may not
  // be higher than the top of its containing block."  (Since the
  // containing block is the content edge of the block box, this
  // means the margin edge of the float can't be higher than the
  // content edge of the block that contains it.)
  floatPos.B(wm) = std::max(mBCoord, ContentBStart());

  // Reflow the float after computing its vertical position so it knows
  // where to break.
  if (!earlyFloatReflow) {
    bool pushedDown = mBCoord != saveBCoord;
    mBlock->ReflowFloat(*this, adjustedAvailableSpace, aFloat, floatMargin,
                        floatOffsets, pushedDown, reflowStatus);
  }
  if (aFloat->GetPrevInFlow())
    floatMargin.BStart(wm) = 0;
  if (NS_FRAME_IS_NOT_COMPLETE(reflowStatus))
    floatMargin.BEnd(wm) = 0;

void
nsColumnSetFrame::PaintColumnRule(nsRenderingContext* aCtx,
                                  const nsRect& aDirtyRect,
                                  const nsPoint& aPt)
{
  nsIFrame* child = mFrames.FirstChild();
  if (!child)
    return;  // no columns

  nsIFrame* nextSibling = child->GetNextSibling();
  if (!nextSibling)
    return;  // 1 column only - this means no gap to draw on

  WritingMode wm = GetWritingMode();
  bool isVertical = wm.IsVertical();
  bool isRTL = !wm.IsBidiLTR();
  const nsStyleColumn* colStyle = StyleColumn();

  uint8_t ruleStyle;
  // Per spec, inset => ridge and outset => groove
  if (colStyle->mColumnRuleStyle == NS_STYLE_BORDER_STYLE_INSET)
    ruleStyle = NS_STYLE_BORDER_STYLE_RIDGE;
  else if (colStyle->mColumnRuleStyle == NS_STYLE_BORDER_STYLE_OUTSET)
    ruleStyle = NS_STYLE_BORDER_STYLE_GROOVE;
  else
    ruleStyle = colStyle->mColumnRuleStyle;

  nsPresContext* presContext = PresContext();
  nscoord ruleWidth = colStyle->GetComputedColumnRuleWidth();
  if (!ruleWidth)
    return;

  nscolor ruleColor =
    GetVisitedDependentColor(eCSSProperty_column_rule_color);

  // In order to re-use a large amount of code, we treat the column rule as a border.
  // We create a new border style object and fill in all the details of the column rule as
  // the left border. PaintBorder() does all the rendering for us, so we not
  // only save an enormous amount of code but we'll support all the line styles that
  // we support on borders!
  nsStyleBorder border(presContext);
  Sides skipSides;
  if (isVertical) {
    border.SetBorderWidth(eSideTop, ruleWidth);
    border.SetBorderStyle(eSideTop, ruleStyle);
    border.mBorderTopColor = StyleComplexColor::FromColor(ruleColor);
    skipSides |= mozilla::eSideBitsLeftRight;
    skipSides |= mozilla::eSideBitsBottom;
  } else {
    border.SetBorderWidth(eSideLeft, ruleWidth);
    border.SetBorderStyle(eSideLeft, ruleStyle);
    border.mBorderLeftColor = StyleComplexColor::FromColor(ruleColor);
    skipSides |= mozilla::eSideBitsTopBottom;
    skipSides |= mozilla::eSideBitsRight;
  }

  // Get our content rect as an absolute coordinate, not relative to
  // our parent (which is what the X and Y normally is)
  nsRect contentRect = GetContentRect() - GetRect().TopLeft() + aPt;
  nsSize ruleSize = isVertical ? nsSize(contentRect.width, ruleWidth)
                               : nsSize(ruleWidth, contentRect.height);

  while (nextSibling) {
    // The frame tree goes RTL in RTL.
    // The |prevFrame| and |nextFrame| frames here are the visually preceding
    // (left/above) and following (right/below) frames, not in logical writing-
    // mode direction.
    nsIFrame* prevFrame = isRTL ? nextSibling : child;
    nsIFrame* nextFrame = isRTL ? child : nextSibling;

    // Each child frame's position coordinates is actually relative to this
    // nsColumnSetFrame.
    // linePt will be at the top-left edge to paint the line.
    nsPoint linePt;
    if (isVertical) {
      nscoord edgeOfPrev = prevFrame->GetRect().YMost() + aPt.y;
      nscoord edgeOfNext = nextFrame->GetRect().Y() + aPt.y;
      linePt = nsPoint(contentRect.x,
                       (edgeOfPrev + edgeOfNext - ruleSize.height) / 2);
    } else {
      nscoord edgeOfPrev = prevFrame->GetRect().XMost() + aPt.x;
      nscoord edgeOfNext = nextFrame->GetRect().X() + aPt.x;
      linePt = nsPoint((edgeOfPrev + edgeOfNext - ruleSize.width) / 2,
                       contentRect.y);
    }

    nsRect lineRect(linePt, ruleSize);

    // Assert that we're not drawing a border-image here; if we were, we
    // couldn't ignore the DrawResult that PaintBorderWithStyleBorder returns.
    MOZ_ASSERT(border.mBorderImageSource.GetType() == eStyleImageType_Null);

    Unused <<
      nsCSSRendering::PaintBorderWithStyleBorder(presContext, *aCtx, this,
                                                 aDirtyRect, lineRect, border,
                                                 StyleContext(),
                                                 PaintBorderFlags::SYNC_DECODE_IMAGES,
                                                 skipSides);

    child = nextSibling;
//.........这里部分代码省略.........

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.........

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);
}

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;
}

/* virtual */ bool
nsInlineFrame::IsSelfEmpty()
{
#if 0
  // I used to think inline frames worked this way, but it seems they
  // don't.  At least not in our codebase.
  if (GetPresContext()->CompatibilityMode() == eCompatibility_FullStandards) {
    return false;
  }
#endif
  const nsStyleMargin* margin = StyleMargin();
  const nsStyleBorder* border = StyleBorder();
  const nsStylePadding* padding = StylePadding();
  // Block-start and -end ignored, since they shouldn't affect things, but this
  // doesn't really match with nsLineLayout.cpp's setting of
  // ZeroEffectiveSpanBox, anymore, so what should this really be?
  WritingMode wm = GetWritingMode();
  bool haveStart, haveEnd;
  // Initially set up haveStart and haveEnd in terms of visual (LTR/TTB)
  // coordinates; we'll exchange them later if bidi-RTL is in effect to
  // get logical start and end flags.
  if (wm.IsVertical()) {
    haveStart =
      border->GetComputedBorderWidth(eSideTop) != 0 ||
      !nsLayoutUtils::IsPaddingZero(padding->mPadding.GetTop()) ||
      !IsMarginZero(margin->mMargin.GetTop());
    haveEnd =
      border->GetComputedBorderWidth(eSideBottom) != 0 ||
      !nsLayoutUtils::IsPaddingZero(padding->mPadding.GetBottom()) ||
      !IsMarginZero(margin->mMargin.GetBottom());
  } else {
    haveStart =
      border->GetComputedBorderWidth(eSideLeft) != 0 ||
      !nsLayoutUtils::IsPaddingZero(padding->mPadding.GetLeft()) ||
      !IsMarginZero(margin->mMargin.GetLeft());
    haveEnd =
      border->GetComputedBorderWidth(eSideRight) != 0 ||
      !nsLayoutUtils::IsPaddingZero(padding->mPadding.GetRight()) ||
      !IsMarginZero(margin->mMargin.GetRight());
  }
  if (haveStart || haveEnd) {
    // We skip this block and return false for box-decoration-break:clone since
    // in that case all the continuations will have the border/padding/margin.
    if ((GetStateBits() & NS_FRAME_PART_OF_IBSPLIT) &&
        StyleBorder()->mBoxDecorationBreak == StyleBoxDecorationBreak::Slice) {
      // When direction=rtl, we need to consider logical rather than visual
      // start and end, so swap the flags.
      if (!wm.IsBidiLTR()) {
        Swap(haveStart, haveEnd);
      }
      // For ib-split frames, ignore things we know we'll skip in GetSkipSides.
      // XXXbz should we be doing this for non-ib-split frames too, in a more
      // general way?

      // Get the first continuation eagerly, as a performance optimization, to
      // avoid having to get it twice..
      nsIFrame* firstCont = FirstContinuation();
      return
        (!haveStart || firstCont->FrameIsNonFirstInIBSplit()) &&
        (!haveEnd || firstCont->FrameIsNonLastInIBSplit());
    }
    return false;
  }
  return true;
}