bool
nsColumnSetFrame::ReflowChildren(nsHTMLReflowMetrics&     aDesiredSize,
                                 const nsHTMLReflowState& aReflowState,
                                 nsReflowStatus&          aStatus,
                                 const ReflowConfig&      aConfig,
                                 bool                     aUnboundedLastColumn,
                                 nsCollapsingMargin*      aBottomMarginCarriedOut,
                                 ColumnBalanceData&       aColData)
{
  aColData.Reset();
  bool allFit = true;
  bool RTL = GetStyleVisibility()->mDirection == NS_STYLE_DIRECTION_RTL;
  bool shrinkingHeightOnly = !NS_SUBTREE_DIRTY(this) &&
    mLastBalanceHeight > aConfig.mColMaxHeight;
  
#ifdef DEBUG_roc
  printf("*** Doing column reflow pass: mLastBalanceHeight=%d, mColMaxHeight=%d, RTL=%d\n, mBalanceColCount=%d, mColWidth=%d, mColGap=%d\n",
         mLastBalanceHeight, aConfig.mColMaxHeight, RTL, aConfig.mBalanceColCount,
         aConfig.mColWidth, aConfig.mColGap);
#endif

  DrainOverflowColumns();
  
  if (mLastBalanceHeight != aConfig.mColMaxHeight) {
    mLastBalanceHeight = aConfig.mColMaxHeight;
    // 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
  const nsMargin &borderPadding = aReflowState.mComputedBorderPadding;
  
  nsRect contentRect(0, 0, 0, 0);
  nsOverflowAreas overflowRects;

  nsIFrame* child = mFrames.FirstChild();
  nsPoint childOrigin = nsPoint(borderPadding.left, borderPadding.top);
  // For RTL, figure out where the last column's left edge should be. 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 unnecessarily.
  nscoord targetX = borderPadding.left;
  if (RTL) {
    nscoord availWidth = aReflowState.availableWidth;
    if (aReflowState.ComputedWidth() != NS_INTRINSICSIZE) {
      availWidth = aReflowState.ComputedWidth();
    }
    if (availWidth != NS_INTRINSICSIZE) {
      childOrigin.x += availWidth - aConfig.mColWidth;
      targetX += aConfig.mExpectedWidthLeftOver;
#ifdef DEBUG_roc
      printf("*** childOrigin.x = %d\n", childOrigin.x);
#endif
    }
  }
  int columnCount = 0;
  int contentBottom = 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 = !aReflowState.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.
    // (It may also have overflowing content that doesn't care about the available height
    // boundary, but if so, too bad, this optimization is defeated.)
    // We want scrollable overflow here since this is a calculation that
    // affects layout.
    bool skipResizeHeightShrink = shrinkingHeightOnly
      && child->GetScrollableOverflowRect().YMost() <= aConfig.mColMaxHeight;

    nscoord childContentBottom = 0;
    if (!reflowNext && (skipIncremental || skipResizeHeightShrink)) {
      // This child does not need to be reflowed, but we may need to move it
      MoveChildTo(this, child, childOrigin);
      
      // If this is the last frame then make sure we get the right status
      nsIFrame* kidNext = child->GetNextSibling();
      if (kidNext) {
        aStatus = (kidNext->GetStateBits() & NS_FRAME_IS_OVERFLOW_CONTAINER)
                  ? NS_FRAME_OVERFLOW_INCOMPLETE
                  : NS_FRAME_NOT_COMPLETE;
      } else {
        aStatus = mLastFrameStatus;
      }
      childContentBottom = nsLayoutUtils::CalculateContentBottom(child);
#ifdef DEBUG_roc
      printf("*** Skipping child #%d %p (incremental %d, resize height shrink %d): status = %d\n",
             columnCount, (void*)child, skipIncremental, skipResizeHeightShrink, aStatus);
#endif
    } else {
      nsSize availSize(aConfig.mColWidth, aConfig.mColMaxHeight);
      
      if (aUnboundedLastColumn && columnCount == aConfig.mBalanceColCount - 1) {
        availSize.height = GetAvailableContentHeight(aReflowState);
      }
  
      if (reflowNext)
        child->AddStateBits(NS_FRAME_IS_DIRTY);

      nsHTMLReflowState kidReflowState(PresContext(), aReflowState, child,
                                       availSize, availSize.width,
                                       aReflowState.ComputedHeight());
      kidReflowState.mFlags.mIsTopOfPage = true;
      kidReflowState.mFlags.mTableIsSplittable = false;
      kidReflowState.mFlags.mIsColumnBalancing = aConfig.mBalanceColCount < PR_INT32_MAX;

#ifdef DEBUG_roc
      printf("*** Reflowing child #%d %p: availHeight=%d\n",
             columnCount, (void*)child,availSize.height);
#endif

      // Note if the column's next in flow is not being changed by this incremental reflow.
      // This may allow the current column to avoid trying to pull lines from the next column.
      if (child->GetNextSibling() &&
          !(GetStateBits() & NS_FRAME_IS_DIRTY) &&
        !(child->GetNextSibling()->GetStateBits() & NS_FRAME_IS_DIRTY)) {
        kidReflowState.mFlags.mNextInFlowUntouched = true;
      }
    
      nsHTMLReflowMetrics kidDesiredSize(aDesiredSize.mFlags);

      // XXX it would be cool to consult the float manager for the
      // previous block to figure out the region of floats from the
      // previous column that extend into this column, and subtract
      // that region from the new float manager.  So you could stick a
      // really big float in the first column and text in following
      // columns would flow around it.

      // Reflow the frame
      ReflowChild(child, PresContext(), kidDesiredSize, kidReflowState,
                  childOrigin.x + kidReflowState.mComputedMargin.left,
                  childOrigin.y + kidReflowState.mComputedMargin.top,
                  0, aStatus);

      reflowNext = (aStatus & NS_FRAME_REFLOW_NEXTINFLOW) != 0;
    
#ifdef DEBUG_roc
      printf("*** Reflowed child #%d %p: status = %d, desiredSize=%d,%d CarriedOutBottomMargin=%d\n",
             columnCount, (void*)child, aStatus, kidDesiredSize.width, kidDesiredSize.height,
             kidDesiredSize.mCarriedOutBottomMargin.get());
#endif

      NS_FRAME_TRACE_REFLOW_OUT("Column::Reflow", aStatus);

      *aBottomMarginCarriedOut = kidDesiredSize.mCarriedOutBottomMargin;
      
      FinishReflowChild(child, PresContext(), &kidReflowState, 
                        kidDesiredSize, childOrigin.x, childOrigin.y, 0);

      childContentBottom = nsLayoutUtils::CalculateContentBottom(child);
      if (childContentBottom > aConfig.mColMaxHeight) {
        allFit = false;
      }
      if (childContentBottom > availSize.height) {
        aColData.mMaxOverflowingHeight = NS_MAX(childContentBottom,
            aColData.mMaxOverflowingHeight);
      }
    }

    contentRect.UnionRect(contentRect, child->GetRect());

    ConsiderChildOverflow(overflowRects, child);
    contentBottom = NS_MAX(contentBottom, childContentBottom);
    aColData.mLastHeight = childContentBottom;
    aColData.mSumHeight += childContentBottom;

    // Build a continuation column if necessary
    nsIFrame* kidNextInFlow = child->GetNextInFlow();

    if (NS_FRAME_IS_FULLY_COMPLETE(aStatus) && !NS_FRAME_IS_TRUNCATED(aStatus)) {
      NS_ASSERTION(!kidNextInFlow, "next in flow should have been deleted");
      child = nsnull;
      break;
    } else {
      ++columnCount;
      // Make sure that the column has a next-in-flow. If not, we must
      // create one to hold the overflowing stuff, even if we're just
      // going to put it on our overflow list and let *our*
      // next in flow handle it.
      if (!kidNextInFlow) {
        NS_ASSERTION(aStatus & NS_FRAME_REFLOW_NEXTINFLOW,
                     "We have to create a continuation, but the block doesn't want us to reflow it?");

        // We need to create a continuing column
        nsresult rv = CreateNextInFlow(PresContext(), child, kidNextInFlow);
        
        if (NS_FAILED(rv)) {
          NS_NOTREACHED("Couldn't create continuation");
          child = nsnull;
          break;
        }
      }

      // Make sure we reflow a next-in-flow when it switches between being
      // normal or overflow container
      if (NS_FRAME_OVERFLOW_IS_INCOMPLETE(aStatus)) {
        if (!(kidNextInFlow->GetStateBits() & NS_FRAME_IS_OVERFLOW_CONTAINER)) {
          aStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
          reflowNext = true;
          kidNextInFlow->AddStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER);
        }
      }
      else if (kidNextInFlow->GetStateBits() & NS_FRAME_IS_OVERFLOW_CONTAINER) {
        aStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
        reflowNext = true;
        kidNextInFlow->RemoveStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER);
      }
        
      if (columnCount >= aConfig.mBalanceColCount) {
        // No more columns allowed here. Stop.
        aStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
        kidNextInFlow->AddStateBits(NS_FRAME_IS_DIRTY);
        
        // Move any of our leftover columns to our overflow list. Our
        // next-in-flow will eventually pick them up.
        const nsFrameList& continuationColumns = mFrames.RemoveFramesAfter(child);
        if (continuationColumns.NotEmpty()) {
          SetOverflowFrames(PresContext(), continuationColumns);
        }
        child = nsnull;
        break;
      }
    }

    if (PresContext()->HasPendingInterrupt()) {
      // Stop the loop now while |child| still points to the frame that bailed
      // out.  We could keep going here and condition a bunch of the code in
      // this loop on whether there's an interrupt, or even just keep going and
      // trying to reflow the blocks (even though we know they'll interrupt
      // right after their first line), but stopping now is conceptually the
      // simplest (and probably fastest) thing.
      break;
    }

    // Advance to the next column
    child = child->GetNextSibling();

    if (child) {
      if (!RTL) {
        childOrigin.x += aConfig.mColWidth + aConfig.mColGap;
      } else {
        childOrigin.x -= aConfig.mColWidth + aConfig.mColGap;
      }
      
#ifdef DEBUG_roc
      printf("*** NEXT CHILD ORIGIN.x = %d\n", childOrigin.x);
#endif
    }
  }

  if (PresContext()->CheckForInterrupt(this) &&
      (GetStateBits() & NS_FRAME_IS_DIRTY)) {
    // Mark all our kids starting with |child| dirty

    // Note that this is a CheckForInterrupt call, not a HasPendingInterrupt,
    // because we might have interrupted while reflowing |child|, and since
    // we're about to add a dirty bit to |child| we need to make sure that
    // |this| is scheduled to have dirty bits marked on it and its ancestors.
    // Otherwise, when we go to mark dirty bits on |child|'s ancestors we'll
    // bail out immediately, since it'll already have a dirty bit.
    for (; child; child = child->GetNextSibling()) {
      child->AddStateBits(NS_FRAME_IS_DIRTY);
    }
  }
  
  // If we're doing RTL, we need to make sure our last column is at the left-hand side of the frame.
  if (RTL && childOrigin.x != targetX) {
    overflowRects.Clear();
    contentRect = nsRect(0, 0, 0, 0);
    PRInt32 deltaX = targetX - childOrigin.x;
#ifdef DEBUG_roc
    printf("*** CHILDORIGIN.x = %d, targetX = %d, DELTAX = %d\n", childOrigin.x, targetX, deltaX);
#endif
    for (child = mFrames.FirstChild(); child; child = child->GetNextSibling()) {
      MoveChildTo(this, child, child->GetPosition() + nsPoint(deltaX, 0));
      ConsiderChildOverflow(overflowRects, child);
      contentRect.UnionRect(contentRect, child->GetRect());
    }
  }
  aColData.mMaxHeight = contentBottom;
  contentRect.height = NS_MAX(contentRect.height, contentBottom);
  mLastFrameStatus = aStatus;
  
  // contentRect included the borderPadding.left,borderPadding.top of the child rects
  contentRect -= nsPoint(borderPadding.left, borderPadding.top);
  
  nsSize contentSize = nsSize(contentRect.XMost(), contentRect.YMost());

  // Apply computed and min/max values
  if (aReflowState.ComputedHeight() != NS_INTRINSICSIZE) {
    contentSize.height = aReflowState.ComputedHeight();
  } else {
    if (NS_UNCONSTRAINEDSIZE != aReflowState.mComputedMaxHeight) {
      contentSize.height = NS_MIN(aReflowState.mComputedMaxHeight, contentSize.height);
    }
    if (NS_UNCONSTRAINEDSIZE != aReflowState.mComputedMinHeight) {
      contentSize.height = NS_MAX(aReflowState.mComputedMinHeight, contentSize.height);
    }
  }
  if (aReflowState.ComputedWidth() != NS_INTRINSICSIZE) {
    contentSize.width = aReflowState.ComputedWidth();
  } else {
    if (NS_UNCONSTRAINEDSIZE != aReflowState.mComputedMaxWidth) {
      contentSize.width = NS_MIN(aReflowState.mComputedMaxWidth, contentSize.width);
    }
    if (NS_UNCONSTRAINEDSIZE != aReflowState.mComputedMinWidth) {
      contentSize.width = NS_MAX(aReflowState.mComputedMinWidth, contentSize.width);
    }
  }
    
  aDesiredSize.height = borderPadding.top + contentSize.height +
    borderPadding.bottom;
  aDesiredSize.width = contentSize.width + borderPadding.left + borderPadding.right;
  aDesiredSize.mOverflowAreas = overflowRects;
  aDesiredSize.UnionOverflowAreasWithDesiredBounds();

#ifdef DEBUG_roc
  printf("*** DONE PASS feasible=%d\n", allFit && NS_FRAME_IS_FULLY_COMPLETE(aStatus)
         && !NS_FRAME_IS_TRUNCATED(aStatus));
#endif
  return allFit && NS_FRAME_IS_FULLY_COMPLETE(aStatus)
    && !NS_FRAME_IS_TRUNCATED(aStatus);
}
Ejemplo n.º 2
0
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.
    // (It may also have overflowing content that doesn't care about the available height
    // boundary, but if so, too bad, this optimization is defeated.)
    // We want scrollable overflow here since this is a calculation that
    // affects layout.
    bool skipResizeBSizeShrink = false;
    if (shrinkingBSizeOnly) {
      switch (wm.GetBlockDir()) {
      case WritingMode::eBlockTB:
        if (child->GetScrollableOverflowRect().YMost() <= aConfig.mColMaxBSize) {
          skipResizeBSizeShrink = true;
        }
        break;
      case WritingMode::eBlockLR:
        if (child->GetScrollableOverflowRect().XMost() <= aConfig.mColMaxBSize) {
          skipResizeBSizeShrink = true;
        }
        break;
      case WritingMode::eBlockRL:
        // XXX not sure how to handle this, so for now just don't attempt
        // the optimization
        break;
      default:
        NS_NOTREACHED("unknown block direction");
        break;
      }
    }

    nscoord childContentBEnd = 0;
    if (!reflowNext && (skipIncremental || skipResizeBSizeShrink)) {
      // This child does not need to be reflowed, but we may need to move it
      MoveChildTo(child, childOrigin, wm, containerSize);

      // If this is the last frame then make sure we get the right status
      nsIFrame* kidNext = child->GetNextSibling();
      if (kidNext) {
        aStatus = (kidNext->GetStateBits() & NS_FRAME_IS_OVERFLOW_CONTAINER)
                  ? NS_FRAME_OVERFLOW_INCOMPLETE
                  : NS_FRAME_NOT_COMPLETE;
      } else {
        aStatus = mLastFrameStatus;
      }
      childContentBEnd = nsLayoutUtils::CalculateContentBEnd(wm, child);
#ifdef DEBUG_roc
      printf("*** Skipping child #%d %p (incremental %d, resize block-size shrink %d): status = %d\n",
             columnCount, (void*)child, skipIncremental, skipResizeBSizeShrink, aStatus);
#endif
    } else {
      LogicalSize availSize(wm, aConfig.mColISize, aConfig.mColMaxBSize);
      if (aUnboundedLastColumn && columnCount == aConfig.mBalanceColCount - 1) {
        availSize.BSize(wm) = GetAvailableContentBSize(aReflowInput);
      }

      LogicalSize computedSize = aReflowInput.ComputedSize(wm);

      if (reflowNext)
        child->AddStateBits(NS_FRAME_IS_DIRTY);

      LogicalSize kidCBSize(wm, availSize.ISize(wm), computedSize.BSize(wm));
      ReflowInput kidReflowInput(PresContext(), aReflowInput, child,
                                       availSize, &kidCBSize);
      kidReflowInput.mFlags.mIsTopOfPage = true;
      kidReflowInput.mFlags.mTableIsSplittable = false;
      kidReflowInput.mFlags.mIsColumnBalancing = aConfig.mBalanceColCount < INT32_MAX;

      // We need to reflow any float placeholders, even if our column height
      // hasn't changed.
      kidReflowInput.mFlags.mMustReflowPlaceholders = !colBSizeChanged;

#ifdef DEBUG_roc
      printf("*** Reflowing child #%d %p: availHeight=%d\n",
             columnCount, (void*)child,availSize.BSize(wm));
#endif

      // Note if the column's next in flow is not being changed by this incremental reflow.
      // This may allow the current column to avoid trying to pull lines from the next column.
      if (child->GetNextSibling() &&
          !(GetStateBits() & NS_FRAME_IS_DIRTY) &&
        !(child->GetNextSibling()->GetStateBits() & NS_FRAME_IS_DIRTY)) {
        kidReflowInput.mFlags.mNextInFlowUntouched = true;
      }

      ReflowOutput kidDesiredSize(wm, aDesiredSize.mFlags);

      // XXX it would be cool to consult the float manager for the
      // previous block to figure out the region of floats from the
      // previous column that extend into this column, and subtract
      // that region from the new float manager.  So you could stick a
      // really big float in the first column and text in following
      // columns would flow around it.

      // Reflow the frame
      LogicalPoint origin(wm,
                          childOrigin.I(wm) +
                          kidReflowInput.ComputedLogicalMargin().IStart(wm),
                          childOrigin.B(wm) +
                          kidReflowInput.ComputedLogicalMargin().BStart(wm));
      ReflowChild(child, PresContext(), kidDesiredSize, kidReflowInput,
                  wm, origin, containerSize, 0, aStatus);

      reflowNext = (aStatus & NS_FRAME_REFLOW_NEXTINFLOW) != 0;

#ifdef DEBUG_roc
      printf("*** Reflowed child #%d %p: status = %d, desiredSize=%d,%d CarriedOutBEndMargin=%d\n",
             columnCount, (void*)child, aStatus, kidDesiredSize.Width(), kidDesiredSize.Height(),
             kidDesiredSize.mCarriedOutBEndMargin.get());
#endif

      NS_FRAME_TRACE_REFLOW_OUT("Column::Reflow", aStatus);

      *aCarriedOutBEndMargin = kidDesiredSize.mCarriedOutBEndMargin;

      FinishReflowChild(child, PresContext(), kidDesiredSize,
                        &kidReflowInput, wm, childOrigin, containerSize, 0);

      childContentBEnd = nsLayoutUtils::CalculateContentBEnd(wm, child);
      if (childContentBEnd > aConfig.mColMaxBSize) {
        allFit = false;
      }
      if (childContentBEnd > availSize.BSize(wm)) {
        aColData.mMaxOverflowingBSize = std::max(childContentBEnd,
            aColData.mMaxOverflowingBSize);
      }
    }

    contentRect.UnionRect(contentRect, child->GetRect());

    ConsiderChildOverflow(overflowRects, child);
    contentBEnd = std::max(contentBEnd, childContentBEnd);
    aColData.mLastBSize = childContentBEnd;
    aColData.mSumBSize += childContentBEnd;

    // Build a continuation column if necessary
    nsIFrame* kidNextInFlow = child->GetNextInFlow();

    if (NS_FRAME_IS_FULLY_COMPLETE(aStatus) && !NS_FRAME_IS_TRUNCATED(aStatus)) {
      NS_ASSERTION(!kidNextInFlow, "next in flow should have been deleted");
      child = nullptr;
      break;
    } else {
      ++columnCount;
      // Make sure that the column has a next-in-flow. If not, we must
      // create one to hold the overflowing stuff, even if we're just
      // going to put it on our overflow list and let *our*
      // next in flow handle it.
      if (!kidNextInFlow) {
        NS_ASSERTION(aStatus & NS_FRAME_REFLOW_NEXTINFLOW,
                     "We have to create a continuation, but the block doesn't want us to reflow it?");

        // We need to create a continuing column
        kidNextInFlow = CreateNextInFlow(child);
      }

      // Make sure we reflow a next-in-flow when it switches between being
      // normal or overflow container
      if (NS_FRAME_OVERFLOW_IS_INCOMPLETE(aStatus)) {
        if (!(kidNextInFlow->GetStateBits() & NS_FRAME_IS_OVERFLOW_CONTAINER)) {
          aStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
          reflowNext = true;
          kidNextInFlow->AddStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER);
        }
      }
      else if (kidNextInFlow->GetStateBits() & NS_FRAME_IS_OVERFLOW_CONTAINER) {
        aStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
        reflowNext = true;
        kidNextInFlow->RemoveStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER);
      }

      if ((contentBEnd > aReflowInput.ComputedMaxBSize() ||
           contentBEnd > aReflowInput.ComputedBSize()) &&
           aConfig.mBalanceColCount < INT32_MAX) {
        // We overflowed vertically, but have not exceeded the number of
        // columns. We're going to go into overflow columns now, so balancing
        // no longer applies.
        aColData.mHasExcessBSize = true;
      }

      if (columnCount >= aConfig.mBalanceColCount) {
        // No more columns allowed here. Stop.
        aStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
        kidNextInFlow->AddStateBits(NS_FRAME_IS_DIRTY);
        // Move any of our leftover columns to our overflow list. Our
        // next-in-flow will eventually pick them up.
        const nsFrameList& continuationColumns = mFrames.RemoveFramesAfter(child);
        if (continuationColumns.NotEmpty()) {
          SetOverflowFrames(continuationColumns);
        }
        child = nullptr;
        break;
      }
    }

    if (PresContext()->HasPendingInterrupt()) {
      // Stop the loop now while |child| still points to the frame that bailed
      // out.  We could keep going here and condition a bunch of the code in
      // this loop on whether there's an interrupt, or even just keep going and
      // trying to reflow the blocks (even though we know they'll interrupt
      // right after their first line), but stopping now is conceptually the
      // simplest (and probably fastest) thing.
      break;
    }

    // Advance to the next column
    child = child->GetNextSibling();

    if (child) {
      childOrigin.I(wm) += aConfig.mColISize + aConfig.mColGap;

#ifdef DEBUG_roc
      printf("*** NEXT CHILD ORIGIN.icoord = %d\n", childOrigin.I(wm));
#endif
    }
  }

  if (PresContext()->CheckForInterrupt(this) &&
      (GetStateBits() & NS_FRAME_IS_DIRTY)) {
    // Mark all our kids starting with |child| dirty

    // Note that this is a CheckForInterrupt call, not a HasPendingInterrupt,
    // because we might have interrupted while reflowing |child|, and since
    // we're about to add a dirty bit to |child| we need to make sure that
    // |this| is scheduled to have dirty bits marked on it and its ancestors.
    // Otherwise, when we go to mark dirty bits on |child|'s ancestors we'll
    // bail out immediately, since it'll already have a dirty bit.
    for (; child; child = child->GetNextSibling()) {
      child->AddStateBits(NS_FRAME_IS_DIRTY);
    }
  }

  aColData.mMaxBSize = contentBEnd;
  LogicalSize contentSize = LogicalSize(wm, contentRect.Size());
  contentSize.BSize(wm) = std::max(contentSize.BSize(wm), contentBEnd);
  mLastFrameStatus = aStatus;

  // Apply computed and min/max values
  if (aConfig.mComputedBSize != NS_INTRINSICSIZE) {
    if (aReflowInput.AvailableBSize() != NS_INTRINSICSIZE) {
      contentSize.BSize(wm) = std::min(contentSize.BSize(wm),
                                       aConfig.mComputedBSize);
    } else {
      contentSize.BSize(wm) = aConfig.mComputedBSize;
    }
  } else {
    // We add the "consumed" block-size back in so that we're applying
    // constraints to the correct bSize value, then subtract it again
    // after we've finished with the min/max calculation. This prevents us from
    // having a last continuation that is smaller than the min bSize. but which
    // has prev-in-flows, trigger a larger bSize than actually required.
    contentSize.BSize(wm) =
      aReflowInput.ApplyMinMaxBSize(contentSize.BSize(wm),
                                    aConfig.mConsumedBSize);
  }
  if (aReflowInput.ComputedISize() != NS_INTRINSICSIZE) {
    contentSize.ISize(wm) = aReflowInput.ComputedISize();
  } else {
    contentSize.ISize(wm) =
      aReflowInput.ApplyMinMaxISize(contentSize.ISize(wm));
  }

  contentSize.ISize(wm) += borderPadding.IStartEnd(wm);
  contentSize.BSize(wm) += borderPadding.BStartEnd(wm);
  aDesiredSize.SetSize(wm, contentSize);
  aDesiredSize.mOverflowAreas = overflowRects;
  aDesiredSize.UnionOverflowAreasWithDesiredBounds();

  // In vertical-rl mode, make a second pass if necessary to reposition the
  // columns with the correct container width. (In other writing modes,
  // correct containerSize was not required for column positioning so we don't
  // need this fixup.)
  if (wm.IsVerticalRL() && containerSize.width != contentSize.Width(wm)) {
    const nsSize finalContainerSize = aDesiredSize.PhysicalSize();
    for (nsIFrame* child : mFrames) {
      // Get the logical position as set previously using a provisional or
      // dummy containerSize, and reset with the correct container size.
      child->SetPosition(wm, child->GetLogicalPosition(wm, containerSize),
                         finalContainerSize);
    }
  }

#ifdef DEBUG_roc
  printf("*** DONE PASS feasible=%d\n", allFit && NS_FRAME_IS_FULLY_COMPLETE(aStatus)
         && !NS_FRAME_IS_TRUNCATED(aStatus));
#endif
  return allFit && NS_FRAME_IS_FULLY_COMPLETE(aStatus)
    && !NS_FRAME_IS_TRUNCATED(aStatus);
}