gecko-dev/layout/tables/nsTableRowFrame.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Netscape Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s): 
 */
#include "nsTableRowFrame.h"
#include "nsIRenderingContext.h"
#include "nsIPresShell.h"
#include "nsIPresContext.h"
#include "nsIStyleContext.h"
#include "nsStyleConsts.h"
#include "nsIHTMLAttributes.h"
#include "nsHTMLAtoms.h"
#include "nsIContent.h"
#include "nsTableFrame.h"
#include "nsTableCellFrame.h"
#include "nsIView.h"
#include "nsIReflowCommand.h"
#include "nsCSSRendering.h"
#include "nsHTMLIIDs.h"
#include "nsLayoutAtoms.h"
#include "nsHTMLParts.h"
#include "nsTableColGroupFrame.h"
#include "nsTableColFrame.h"
#include "nsCOMPtr.h"
// the following header files are required for style optimizations that work only when the child content is really a cell
#include "nsIHTMLTableCellElement.h"
// end includes for style optimizations that require real content knowledge


struct nsTableCellReflowState : public nsHTMLReflowState
{
  nsTableCellReflowState(nsIPresContext*          aPresContext,
                         const nsHTMLReflowState& aParentReflowState,
                         nsIFrame*                aFrame,
                         const nsSize&            aAvailableSpace,
                         nsReflowReason           aReason);

  nsTableCellReflowState(nsIPresContext*          aPresContext,
                         const nsHTMLReflowState& aParentReflowState,
                         nsIFrame*                aFrame,
                         const nsSize&            aAvailableSpace);

  void FixUp(const nsSize& aAvailSpace);
};

nsTableCellReflowState::nsTableCellReflowState(nsIPresContext*          aPresContext,
                                               const nsHTMLReflowState& aParentRS,
                                               nsIFrame*                aFrame,
                                               const nsSize&            aAvailSpace,
                                               nsReflowReason           aReason)
  :nsHTMLReflowState(aPresContext, aParentRS, aFrame, aAvailSpace, aReason)
{
  FixUp(aAvailSpace);
}

nsTableCellReflowState::nsTableCellReflowState(nsIPresContext*          aPresContext,
                                               const nsHTMLReflowState& aParentRS,
                                               nsIFrame*                aFrame,
                                               const nsSize&            aAvailSpace)
  :nsHTMLReflowState(aPresContext, aParentRS, aFrame, aAvailSpace)
{
  FixUp(aAvailSpace);
}

void nsTableCellReflowState::FixUp(const nsSize& aAvailSpace)
{
  // fix the mComputed values during a pass 2 reflow since the cell can be a percentage base
  if (NS_UNCONSTRAINEDSIZE != aAvailSpace.width) {
    if (NS_UNCONSTRAINEDSIZE != mComputedWidth) {
      mComputedWidth = aAvailSpace.width - mComputedBorderPadding.left - mComputedBorderPadding.right;
      mComputedWidth = PR_MAX(0, mComputedWidth);
    }
    if (NS_UNCONSTRAINEDSIZE != mComputedHeight) {
      if (NS_UNCONSTRAINEDSIZE != aAvailSpace.height) {
        mComputedHeight = aAvailSpace.height - mComputedBorderPadding.top - mComputedBorderPadding.bottom;
        mComputedHeight = PR_MAX(0, mComputedHeight);
      }
    }
  }
}

// 'old' is old cached cell's desired size
// 'new' is new cell's size including style constraints
static PRBool
TallestCellGotShorter(nscoord aOld,
                      nscoord aNew,
                      nscoord aTallest)
{
  return ((aNew < aOld) && (aOld == aTallest));
}

/* ----------- nsTableRowpFrame ---------- */

nsTableRowFrame::nsTableRowFrame()
  : nsHTMLContainerFrame(),
    mAllBits(0)
{
  mBits.mMinRowSpan = 1;
  mBits.mRowIndex   = 0;
  ResetTallestCell(0);
#ifdef DEBUG_TABLE_REFLOW_TIMING
  mTimer = new nsReflowTimer(this);
#endif
}

nsTableRowFrame::~nsTableRowFrame()
{
#ifdef DEBUG_TABLE_REFLOW_TIMING
  nsTableFrame::DebugReflowDone(this);
#endif
}

NS_IMETHODIMP
nsTableRowFrame::Init(nsIPresContext*  aPresContext,
                      nsIContent*      aContent,
                      nsIFrame*        aParent,
                      nsIStyleContext* aContext,
                      nsIFrame*        aPrevInFlow)
{
  nsresult  rv;

  // Let the the base class do its initialization
  rv = nsHTMLContainerFrame::Init(aPresContext, aContent, aParent, aContext,
                                  aPrevInFlow);

  // record that children that are ignorable whitespace should be excluded 
  mState |= NS_FRAME_EXCLUDE_IGNORABLE_WHITESPACE;

  if (aPrevInFlow) {
    // Set the row index
    nsTableRowFrame* rowFrame = (nsTableRowFrame*)aPrevInFlow;
    
    SetRowIndex(rowFrame->GetRowIndex());
  }

  return rv;
}


NS_IMETHODIMP
nsTableRowFrame::AppendFrames(nsIPresContext* aPresContext,
                              nsIPresShell&   aPresShell,
                              nsIAtom*        aListName,
                              nsIFrame*       aFrameList)
{
  // Append the frames
  mFrames.AppendFrames(nsnull, aFrameList);

  // Add the new cell frames to the table
  nsTableFrame *tableFrame = nsnull;
  nsTableFrame::GetTableFrame(this, tableFrame);
  for (nsIFrame* childFrame = aFrameList; childFrame; childFrame->GetNextSibling(&childFrame)) {
    nsCOMPtr<nsIAtom> frameType;
    childFrame->GetFrameType(getter_AddRefs(frameType));
    if (nsLayoutAtoms::tableCellFrame == frameType.get()) {
      // Add the cell to the cell map
      tableFrame->AppendCell(*aPresContext, (nsTableCellFrame&)*childFrame, GetRowIndex());
      // XXX this could be optimized with some effort
      tableFrame->SetNeedStrategyInit(PR_TRUE);
    }
  }

  // Reflow the new frames. They're already marked dirty, so generate a reflow
  // command that tells us to reflow our dirty child frames
  tableFrame->AppendDirtyReflowCommand(&aPresShell, this);

  return NS_OK;
}


NS_IMETHODIMP
nsTableRowFrame::InsertFrames(nsIPresContext* aPresContext,
                              nsIPresShell&   aPresShell,
                              nsIAtom*        aListName,
                              nsIFrame*       aPrevFrame,
                              nsIFrame*       aFrameList)
{
  // Get the table frame
  nsTableFrame* tableFrame = nsnull;
  nsTableFrame::GetTableFrame(this, tableFrame);
  
  // gather the new frames (only those which are cells) into an array
  nsTableCellFrame* prevCellFrame = (nsTableCellFrame *)nsTableFrame::GetFrameAtOrBefore(aPresContext, this, aPrevFrame, nsLayoutAtoms::tableCellFrame);
  nsVoidArray cellChildren;
  for (nsIFrame* childFrame = aFrameList; childFrame; childFrame->GetNextSibling(&childFrame)) {
    nsCOMPtr<nsIAtom> frameType;
    childFrame->GetFrameType(getter_AddRefs(frameType));
    if (nsLayoutAtoms::tableCellFrame == frameType.get()) {
      cellChildren.AppendElement(childFrame);
      // XXX this could be optimized with some effort
      tableFrame->SetNeedStrategyInit(PR_TRUE);
    }
  }
  // insert the cells into the cell map
  PRInt32 colIndex = -1;
  if (prevCellFrame) {
    prevCellFrame->GetColIndex(colIndex);
  }
  tableFrame->InsertCells(*aPresContext, cellChildren, GetRowIndex(), colIndex);

  // Insert the frames in the frame list
  mFrames.InsertFrames(nsnull, aPrevFrame, aFrameList);
  
  // Reflow the new frames. They're already marked dirty, so generate a reflow
  // command that tells us to reflow our dirty child frames
  tableFrame->AppendDirtyReflowCommand(&aPresShell, this);

  return NS_OK;
}

NS_IMETHODIMP
nsTableRowFrame::RemoveFrame(nsIPresContext* aPresContext,
                             nsIPresShell&   aPresShell,
                             nsIAtom*        aListName,
                             nsIFrame*       aOldFrame)
{
  // Get the table frame
  nsTableFrame* tableFrame=nsnull;
  nsTableFrame::GetTableFrame(this, tableFrame);
  if (tableFrame) {
    nsCOMPtr<nsIAtom> frameType;
    aOldFrame->GetFrameType(getter_AddRefs(frameType));
    if (nsLayoutAtoms::tableCellFrame == frameType.get()) {
      nsTableCellFrame* cellFrame = (nsTableCellFrame*)aOldFrame;
      PRInt32 colIndex;
      cellFrame->GetColIndex(colIndex);
      // remove the cell from the cell map
      tableFrame->RemoveCell(*aPresContext, cellFrame, GetRowIndex());
      // XXX this could be optimized with some effort
      tableFrame->SetNeedStrategyInit(PR_TRUE);

      // Remove the frame and destroy it
      mFrames.DestroyFrame(aPresContext, aOldFrame);

      // XXX This could probably be optimized with much effort
      tableFrame->SetNeedStrategyInit(PR_TRUE);
      // Generate a reflow command so we reflow the table itself.
      // Target the row so that it gets a dirty reflow before a resize reflow
      // in case another cell gets added to the row during a reflow coallesce.
      tableFrame->AppendDirtyReflowCommand(&aPresShell, this);
    }
  }

  return NS_OK;
}

nscoord 
GetHeightOfRowsSpannedBelowFirst(nsTableCellFrame& aTableCellFrame,
                                 nsTableFrame&     aTableFrame)
{
  nscoord height = 0;
  nscoord cellSpacingY = aTableFrame.GetCellSpacingY();
  PRInt32 rowSpan = aTableFrame.GetEffectiveRowSpan(aTableCellFrame);
  // add in height of rows spanned beyond the 1st one
  nsIFrame* nextRow = nsnull;
  aTableCellFrame.GetParent((nsIFrame **)&nextRow);
  nextRow->GetNextSibling(&nextRow);
  for (PRInt32 rowX = 1; ((rowX < rowSpan) && nextRow);) {
    nsCOMPtr<nsIAtom> frameType;
    nextRow->GetFrameType(getter_AddRefs(frameType));
    if (nsLayoutAtoms::tableRowFrame == frameType.get()) {
      nsRect rect;
      nextRow->GetRect(rect);
      height += rect.height;
      rowX++;
    }
    height += cellSpacingY;
    nextRow->GetNextSibling(&nextRow);
  }
  return height;
}


/**
 * Post-reflow hook. This is where the table row does its post-processing
 */
void
nsTableRowFrame::DidResize(nsIPresContext*          aPresContext,
                           const nsHTMLReflowState& aReflowState)
{
  // Resize and re-align the cell frames based on our row height
  nsTableFrame* tableFrame;
  nsTableFrame::GetTableFrame(this, tableFrame);
  if (!tableFrame) return;

  nsTableIterator iter(aPresContext, *this, eTableDIR);
  nsIFrame* childFrame = iter.First();

  while (childFrame) {
    nsCOMPtr<nsIAtom> frameType;
    childFrame->GetFrameType(getter_AddRefs(frameType));
    if (nsLayoutAtoms::tableCellFrame == frameType.get()) {
      nsTableCellFrame* cellFrame = (nsTableCellFrame*)childFrame;
      nscoord cellHeight = mRect.height + GetHeightOfRowsSpannedBelowFirst(*cellFrame, *tableFrame);

      // resize the cell's height
      nsSize  cellFrameSize;
      cellFrame->GetSize(cellFrameSize);
      //if (cellFrameSize.height!=cellHeight)
      {
        // XXX If the cell frame has a view, then we need to resize
        // it as well. We would like to only do that if the cell's size
        // is changing. Why is the 'if' stmt above commented out?
        cellFrame->SizeTo(aPresContext, cellFrameSize.width, cellHeight);
        // realign cell content based on the new height
        /*nsHTMLReflowMetrics desiredSize(nsnull);
        nsHTMLReflowState kidReflowState(aPresContext, aReflowState,
                                         cellFrame,
                                         nsSize(cellFrameSize.width, cellHeight),
                                         eReflowReason_Resize);*/
        //XXX: the following reflow is necessary for any content of the cell
        //     whose height is a percent of the cell's height (maybe indirectly.)
        //     But some content crashes when this reflow is issued, to be investigated
        //XXX nsReflowStatus status;
        //ReflowChild(cellFrame, aPresContext, desiredSize, kidReflowState, status);

        cellFrame->VerticallyAlignChild(aPresContext, aReflowState, mMaxCellAscent);
      }
    }
    // Get the next child
    childFrame = iter.Next();
  }

  // Let our base class do the usual work
}

// returns max-ascent amongst all cells that have 'vertical-align: baseline'
// *including* cells with rowspans
nscoord nsTableRowFrame::GetMaxCellAscent() const
{
  return mMaxCellAscent;
}

#if 0 // nobody uses this
// returns max-descent amongst all cells that have 'vertical-align: baseline'
// does *not* include cells with rowspans
nscoord nsTableRowFrame::GetMaxCellDescent() const
{
  return mMaxCellDescent;
}
#endif

/** returns the height of the tallest child in this row (ignoring any cell with rowspans) */
nscoord nsTableRowFrame::GetTallestCell() const
{
  return mTallestCell;
}

void 
nsTableRowFrame::ResetTallestCell(nscoord aRowStyleHeight)
{
  mTallestCell = (NS_UNCONSTRAINEDSIZE == aRowStyleHeight) ? 0 : aRowStyleHeight;
  mMaxCellAscent = 0;
  mMaxCellDescent = 0;
}

void
nsTableRowFrame::SetTallestCell(nscoord           aHeight,
                                nscoord           aAscent,
                                nscoord           aDescent,
                                nsTableFrame*     aTableFrame,
                                nsTableCellFrame* aCellFrame)
{
  NS_ASSERTION((aTableFrame && aCellFrame) , "invalid call");
  if (aHeight != NS_UNCONSTRAINEDSIZE) {
    if (!(aCellFrame->HasVerticalAlignBaseline())) { // only the cell's height matters
      if (mTallestCell < aHeight) {
        PRInt32 rowSpan = aTableFrame->GetEffectiveRowSpan(*aCellFrame);
        if (rowSpan == 1) {
          mTallestCell = aHeight;
        }
      }
    }
    else { // the alignment on the baseline can change the height
      NS_ASSERTION((aAscent != NS_UNCONSTRAINEDSIZE) && (aDescent != NS_UNCONSTRAINEDSIZE), "invalid call");
      // see if this is a long ascender
      if (mMaxCellAscent < aAscent) {
        mMaxCellAscent = aAscent;
      }
      // see if this is a long descender and without rowspan
      if (mMaxCellDescent < aDescent) {
        PRInt32 rowSpan = aTableFrame->GetEffectiveRowSpan(*aCellFrame);
        if (rowSpan == 1) {
          mMaxCellDescent = aDescent;
        }
      }
      // keep the tallest height in sync
      if (mTallestCell < mMaxCellAscent + mMaxCellDescent) {
        mTallestCell = mMaxCellAscent + mMaxCellDescent;
      }
    }
  }
}

void 
nsTableRowFrame::CalcTallestCell()
{
  nsTableFrame* tableFrame = nsnull;
  nsresult rv = nsTableFrame::GetTableFrame(this, tableFrame);
  if (NS_FAILED(rv)) return;

  ResetTallestCell(0);

  for (nsIFrame* kidFrame = mFrames.FirstChild(); kidFrame; kidFrame->GetNextSibling(&kidFrame)) {
    nsCOMPtr<nsIAtom> frameType;
    kidFrame->GetFrameType(getter_AddRefs(frameType));
    if (nsLayoutAtoms::tableCellFrame == frameType.get()) {
      nscoord availWidth = ((nsTableCellFrame *)kidFrame)->GetPriorAvailWidth();
      nsSize desSize = ((nsTableCellFrame *)kidFrame)->GetDesiredSize();
      CalculateCellActualSize(kidFrame, desSize.width, desSize.height, availWidth);
      // height may have changed, adjust descent to absorb any excess difference
      nscoord ascent = ((nsTableCellFrame *)kidFrame)->GetDesiredAscent();
      nscoord descent = desSize.height - ascent;
      SetTallestCell(desSize.height, ascent, descent, tableFrame, (nsTableCellFrame*)kidFrame);
    }
  }
}

#if 0
static
PRBool IsFirstRow(nsIPresContext*  aPresContext,
                  nsTableFrame&    aTable,
                  nsTableRowFrame& aRow)
{
  nsIFrame* firstRowGroup = nsnull;
  aTable.FirstChild(aPresContext, nsnull, &firstRowGroup);
  nsIFrame* rowGroupFrame = nsnull;
  nsresult rv = aRow.GetParent(&rowGroupFrame);
  if (NS_SUCCEEDED(rv) && (rowGroupFrame == firstRowGroup)) {
    nsIFrame* firstRow;
    rowGroupFrame->FirstChild(aPresContext, nsnull, &firstRow);
    return (&aRow == firstRow);
  }
  return PR_FALSE;
}
#endif

NS_METHOD nsTableRowFrame::Paint(nsIPresContext*      aPresContext,
                                 nsIRenderingContext& aRenderingContext,
                                 const nsRect&        aDirtyRect,
                                 nsFramePaintLayer    aWhichLayer,
                                 PRUint32             aFlags)
{
  PRBool isVisible;
  if (NS_SUCCEEDED(IsVisibleForPainting(aPresContext, aRenderingContext, PR_FALSE, &isVisible)) && !isVisible) {
    return NS_OK;
  }
  if ((NS_FRAME_PAINT_LAYER_BACKGROUND == aWhichLayer) &&
      !(aFlags && (NS_ROW_FRAME_PAINT_SKIP_ROW == aFlags))) {
    nsCompatibility mode;
    aPresContext->GetCompatibilityMode(&mode);
    if (eCompatibility_Standard == mode) {
      const nsStyleVisibility* vis = 
      (const nsStyleVisibility*)mStyleContext->GetStyleData(eStyleStruct_Visibility);
      if (vis->IsVisibleOrCollapsed()) {
        const nsStyleBorder* border =
          (const nsStyleBorder*)mStyleContext->GetStyleData(eStyleStruct_Border);
        const nsStyleBackground* color =
          (const nsStyleBackground*)mStyleContext->GetStyleData(eStyleStruct_Background);        
        nsRect rect(0, 0, mRect.width, mRect.height);
        nsCSSRendering::PaintBackground(aPresContext, aRenderingContext, this,
                                        aDirtyRect, rect, *color, *border, 0, 0);
      }
    }
  }

#ifdef DEBUG
  // for debug...
  if ((NS_FRAME_PAINT_LAYER_DEBUG == aWhichLayer) && GetShowFrameBorders()) {
    aRenderingContext.SetColor(NS_RGB(0,255,0));
    aRenderingContext.DrawRect(0, 0, mRect.width, mRect.height);
  }
#endif

  if (!(aFlags && (NS_ROW_FRAME_PAINT_SKIP_CELLS == aFlags))) {
    PaintChildren(aPresContext, aRenderingContext, aDirtyRect, aWhichLayer);
  }
  return NS_OK;

}

PRIntn
nsTableRowFrame::GetSkipSides() const
{
  PRIntn skip = 0;
  if (nsnull != mPrevInFlow) {
    skip |= 1 << NS_SIDE_TOP;
  }
  if (nsnull != mNextInFlow) {
    skip |= 1 << NS_SIDE_BOTTOM;
  }
  return skip;
}

/** overloaded method from nsContainerFrame.  The difference is that 
  * we don't want to clip our children, so a cell can do a rowspan
  */
void nsTableRowFrame::PaintChildren(nsIPresContext*      aPresContext,
                                    nsIRenderingContext& aRenderingContext,
                                    const nsRect&        aDirtyRect,
                                    nsFramePaintLayer    aWhichLayer,
                                    PRUint32             aFlags)
{
  nsIFrame* kid = mFrames.FirstChild();
  while (nsnull != kid) {
    nsIView *pView;
     
    kid->GetView(aPresContext, &pView);
    if (nsnull == pView) {
      nsRect kidRect;
      kid->GetRect(kidRect);
      nsRect damageArea;
      PRBool overlap = damageArea.IntersectRect(aDirtyRect, kidRect);
      if (overlap) {
        PRBool clipState;
        // Translate damage area into kid's coordinate system
        nsRect kidDamageArea(damageArea.x - kidRect.x,
                             damageArea.y - kidRect.y,
                             damageArea.width, damageArea.height);
        aRenderingContext.PushState();
        aRenderingContext.Translate(kidRect.x, kidRect.y);
        kid->Paint(aPresContext, aRenderingContext, kidDamageArea,
                   aWhichLayer);
#ifdef DEBUG
        if ((NS_FRAME_PAINT_LAYER_DEBUG == aWhichLayer) &&
            GetShowFrameBorders()) {
          aRenderingContext.SetColor(NS_RGB(255,0,0));
          aRenderingContext.DrawRect(0, 0, kidRect.width, kidRect.height);
        }
#endif
        aRenderingContext.PopState(clipState);
      }
    }
    kid->GetNextSibling(&kid);
  }
}

/* we overload this here because rows have children that can span outside of themselves.
 * so the default "get the child rect, see if it contains the event point" action isn't
 * sufficient.  We have to ask the row if it has a child that contains the point.
 */
NS_IMETHODIMP
nsTableRowFrame::GetFrameForPoint(nsIPresContext*        aPresContext,
                                       const nsPoint&    aPoint,
                                       nsFramePaintLayer aWhichLayer,
                                       nsIFrame**        aFrame)
{
  // XXX This would not need to exist (except as a one-liner, to make this
  // frame work like a block frame) if rows with rowspan cells made the
  // the NS_FRAME_OUTSIDE_CHILDREN bit of mState set correctly (see
  // nsIFrame.h).

  // I imagine fixing this would help performance of GetFrameForPoint in
  // tables.  It may also fix problems with relative positioning.

  // This is basically copied from nsContainerFrame::GetFrameForPointUsing,
  // except for one bit removed

  nsIFrame *kid, *hit;
  nsPoint tmp;

  PRBool inThisFrame = mRect.Contains(aPoint);

  FirstChild(aPresContext, nsnull, &kid);
  *aFrame = nsnull;
  tmp.MoveTo(aPoint.x - mRect.x, aPoint.y - mRect.y);
  while (nsnull != kid) {
    nsresult rv = kid->GetFrameForPoint(aPresContext, tmp, aWhichLayer, &hit);

    if (NS_SUCCEEDED(rv) && hit) {
      *aFrame = hit;
    }
    kid->GetNextSibling(&kid);
  }

  if (*aFrame) {
    return NS_OK;
  }

  if ( inThisFrame && (aWhichLayer == NS_FRAME_PAINT_LAYER_BACKGROUND)) {
    const nsStyleVisibility* vis = 
      (const nsStyleVisibility*)mStyleContext->GetStyleData(eStyleStruct_Visibility);
    if (vis->IsVisible()) {
      *aFrame = this;
      return NS_OK;
    }
  }

  return NS_ERROR_FAILURE;
}

/* GetMinRowSpan is needed for deviant cases where every cell in a row has a rowspan > 1.
 * It sets mMinRowSpan, which is used in FixMinCellHeight 
 */
void nsTableRowFrame::GetMinRowSpan(nsTableFrame *aTableFrame)
{
  PRInt32 minRowSpan=-1;
  nsIFrame* frame = mFrames.FirstChild();
  while (frame)
  {
    const nsStyleDisplay *kidDisplay;
    frame->GetStyleData(eStyleStruct_Display, ((const nsStyleStruct *&)kidDisplay));
    if (NS_STYLE_DISPLAY_TABLE_CELL == kidDisplay->mDisplay)
    {
      PRInt32 rowSpan = aTableFrame->GetEffectiveRowSpan((nsTableCellFrame &)*frame);
      if (-1==minRowSpan)
        minRowSpan = rowSpan;
      else if (minRowSpan>rowSpan)
        minRowSpan = rowSpan;
    }
    frame->GetNextSibling(&frame);
  }
  mBits.mMinRowSpan = unsigned(minRowSpan);
}

void nsTableRowFrame::FixMinCellHeight(nsTableFrame *aTableFrame)
{
  nsIFrame* frame = mFrames.FirstChild();
  while (frame) {
    nsCOMPtr<nsIAtom> frameType;
    frame->GetFrameType(getter_AddRefs(frameType));
    if (nsLayoutAtoms::tableCellFrame == frameType.get()) {
      PRInt32 rowSpan = aTableFrame->GetEffectiveRowSpan((nsTableCellFrame &)*frame);
      if (PRInt32(mBits.mMinRowSpan) == rowSpan) {
        nsRect rect;
        frame->GetRect(rect);
        if (rect.height > mTallestCell)
          mTallestCell = rect.height;
      }
    }
    frame->GetNextSibling(&frame);
  }
}

// Calculate the cell's actual size given its pass2 desired width and height.
// Takes into account the specified height (in the style), and any special logic
// needed for backwards compatibility.
// Modifies the desired width and height that are passed in.
nsresult
nsTableRowFrame::CalculateCellActualSize(nsIFrame* aCellFrame,
                                         nscoord&  aDesiredWidth,
                                         nscoord&  aDesiredHeight,
                                         nscoord   aAvailWidth)
{
  nscoord                specifiedHeight = 0;
  const nsStylePosition* position;
  
  // Get the height specified in the style information
  aCellFrame->GetStyleData(eStyleStruct_Position, (const nsStyleStruct*&)position);
  
  switch (position->mHeight.GetUnit()) {
    case eStyleUnit_Coord:
      specifiedHeight = position->mHeight.GetCoordValue();
      break;
    case eStyleUnit_Percent: {
      nsTableFrame* table = nsnull;
      nsTableFrame::GetTableFrame(this, table);
      if (table) {
        nscoord basis = table->GetPercentBasisForRows();
        if (basis > 0) {
          float percent = position->mHeight.GetPercentValue();
          specifiedHeight = NSToCoordRound(percent * ((float)basis));
        }
      }
      break;
    }
    case eStyleUnit_Inherit:
      // XXX for now, do nothing
    case eStyleUnit_Auto:
    default:
      break;
  }

  // If the specified height is greater than the desired height, then use the
  // specified height
  if (specifiedHeight > aDesiredHeight)
    aDesiredHeight = specifiedHeight;
 
  if (0 == aDesiredWidth) { // special Nav4 compatibility code for the width
    aDesiredWidth = aAvailWidth;
  } 

  return NS_OK;
}

// Calculates the available width for the table cell based on the known
// column widths taking into account column spans and column spacing
nscoord 
CalcCellAvailWidth(nsTableFrame&     aTableFrame,
                   nsTableCellFrame& aCellFrame,
                   nscoord           aCellSpacingX)
{
  nscoord cellWidth = 0;
  PRInt32 colIndex;
  aCellFrame.GetColIndex(colIndex);
  PRInt32 colspan = aTableFrame.GetEffectiveColSpan(aCellFrame);

  for (PRInt32 spanX = 0; spanX < colspan; spanX++) {
    nscoord colWidth = aTableFrame.GetColumnWidth(colIndex + spanX);
    if (colWidth > 0) {
      cellWidth += colWidth;
    }
    if ((spanX > 0) && (aTableFrame.GetNumCellsOriginatingInCol(colIndex + spanX) > 0)) {
      cellWidth += aCellSpacingX;
    }
  }

  return cellWidth;
}

nscoord
GetSpaceBetween(PRInt32       aPrevColIndex,
                PRInt32       aColIndex,
                PRInt32       aColSpan,
                nsTableFrame& aTableFrame,
                nscoord       aCellSpacingX,
                PRBool        aIsLeftToRight)
{
  nscoord space = 0;
  PRInt32 colX;
  if (aIsLeftToRight) {
    for (colX = aPrevColIndex + 1; aColIndex > colX; colX++) {
      space += aTableFrame.GetColumnWidth(colX);
      if (aTableFrame.GetNumCellsOriginatingInCol(colX) > 0) {
        space += aCellSpacingX;
      }
    }
  } 
  else {
    PRInt32 lastCol = aColIndex + aColSpan - 1;
    for (colX = aPrevColIndex - 1; colX > lastCol; colX--) {
      space += aTableFrame.GetColumnWidth(colX);
      if (aTableFrame.GetNumCellsOriginatingInCol(colX) > 0) {
        space += aCellSpacingX;
      }
    }
  }
  return space;
}


// Called for a dirty or resize reflow. Reflows all the existing table cell 
// frames unless aDirtyOnly is PR_TRUE in which case only reflow the dirty frames

NS_METHOD 
nsTableRowFrame::ReflowChildren(nsIPresContext*          aPresContext,
                                nsHTMLReflowMetrics&     aDesiredSize,
                                const nsHTMLReflowState& aReflowState,
                                nsTableFrame&            aTableFrame,
                                nsReflowStatus&          aStatus,
                                PRBool                   aDirtyOnly)
{
  aStatus = NS_FRAME_COMPLETE;
  if (!mFrames.FirstChild()) return NS_OK;

  nsTableFrame* tableFrame = &aTableFrame;
  if (!tableFrame) return NS_ERROR_NULL_POINTER;
  nsIFrame* tablePrevInFlow;
  tableFrame->GetPrevInFlow(&tablePrevInFlow);
  PRBool isPaginated;
  aPresContext->IsPaginated(&isPaginated);

  nsresult rv = NS_OK;

  nscoord cellSpacingX = tableFrame->GetCellSpacingX();
  PRInt32 cellColSpan = 1;  // must be defined here so it's set properly for non-cell kids
  
  nsTableIteration dir = (aReflowState.availableWidth == NS_UNCONSTRAINEDSIZE)
                         ? eTableLTR : eTableDIR;
  nsTableIterator iter(aPresContext, *this, dir);
  // remember the col index of the previous cell to handle rowspans into this row
  PRInt32 firstPrevColIndex = (iter.IsLeftToRight()) ? -1 : tableFrame->GetColCount();
  PRInt32 prevColIndex  = firstPrevColIndex;
  nscoord x = 0; // running total of children x offset

  PRBool isAutoLayout = tableFrame->IsAutoLayout();
  PRBool needToNotifyTable = PR_TRUE;
  // Reflow each of our existing cell frames
  nsIFrame* kidFrame = iter.First();
  while (kidFrame) {
    // Get the frame state bits
    nsFrameState  frameState;
    kidFrame->GetFrameState(&frameState);
    
    // See if we should only reflow the dirty child frames
    PRBool doReflowChild = PR_TRUE;
    if (aDirtyOnly && ((frameState & NS_FRAME_IS_DIRTY) == 0)) {
      doReflowChild = PR_FALSE;
    }

    nsCOMPtr<nsIAtom> frameType;
    kidFrame->GetFrameType(getter_AddRefs(frameType));

    // Reflow the child frame
    if (doReflowChild) {
      if (nsLayoutAtoms::tableCellFrame == frameType.get()) {
        nsTableCellFrame* cellFrame = (nsTableCellFrame*)kidFrame;
        PRInt32 cellColIndex;
        cellFrame->GetColIndex(cellColIndex);
        cellColSpan = tableFrame->GetEffectiveColSpan(*cellFrame);
   
        x += cellSpacingX;
        // If the adjacent cell is in a prior row (because of a rowspan) add in the space
        if ((iter.IsLeftToRight() && (prevColIndex != (cellColIndex - 1))) ||
            (!iter.IsLeftToRight() && (prevColIndex != cellColIndex + cellColSpan))) {
          x += GetSpaceBetween(prevColIndex, cellColIndex, cellColSpan, *tableFrame, 
                               cellSpacingX, iter.IsLeftToRight());
        }
        // Calculate the available width for the table cell using the known column widths
        nscoord availWidth = CalcCellAvailWidth(*tableFrame, *cellFrame, cellSpacingX);
        if (0 == availWidth) {
          availWidth = NS_UNCONSTRAINEDSIZE;
        }

        // remember the rightmost (ltr) or leftmost (rtl) column this cell spans into
        prevColIndex = (iter.IsLeftToRight()) ? cellColIndex + (cellColSpan - 1) : cellColIndex;
        nsHTMLReflowMetrics desiredSize(nsnull);
  
        // If the avail width is not the same as last time we reflowed the cell or
        // the cell wants to be bigger than what was available last time or
        // it is a style change reflow or we are printing, then we must reflow the
        // cell. Otherwise we can skip the reflow.
        nsIFrame* kidNextInFlow;
        kidFrame->GetNextInFlow(&kidNextInFlow);
        nsSize cellDesiredSize = cellFrame->GetDesiredSize();
        if ((availWidth != cellFrame->GetPriorAvailWidth())           ||
            (cellDesiredSize.width > cellFrame->GetPriorAvailWidth()) ||
            (eReflowReason_StyleChange == aReflowState.reason)        ||
            isPaginated) {
          // Reflow the cell to fit the available width, height
          nsSize  kidAvailSize(availWidth, aReflowState.availableHeight);
          nsReflowReason reason = eReflowReason_Resize;
          PRBool cellToWatch = PR_FALSE;
          nsSize maxElementSize;
          // If it's a dirty frame, then check whether it's the initial reflow
          if (frameState & NS_FRAME_FIRST_REFLOW) {
            reason = eReflowReason_Initial;
            cellToWatch = PR_TRUE;
          }
          else if (eReflowReason_StyleChange == aReflowState.reason) {
            reason = eReflowReason_StyleChange;
            cellToWatch = PR_TRUE;
          }
          if (cellToWatch) {
            cellFrame->DidSetStyleContext(aPresContext); // XXX check this
            if (!tablePrevInFlow && isAutoLayout) {
              // request the maximum width if availWidth is constrained
              // XXX we could just do this always, but blocks have some problems
              if (NS_UNCONSTRAINEDSIZE != availWidth) {
                desiredSize.mFlags |= NS_REFLOW_CALC_MAX_WIDTH; 
              }
              // request to get the max element size 
              desiredSize.maxElementSize = &maxElementSize;
            }
            else {
              cellToWatch = PR_FALSE;
            }
          }
  
          nscoord oldMaxWidth     = cellFrame->GetMaximumWidth();
          nscoord oldMaxElemWidth = cellFrame->GetPass1MaxElementSize().width;

          // Reflow the child
          nsTableCellReflowState kidReflowState(aPresContext, aReflowState, 
                                                kidFrame, kidAvailSize, reason);
          nsReflowStatus status;
          rv = ReflowChild(kidFrame, aPresContext, desiredSize, kidReflowState,
                           x, 0, 0, status);

          if (cellToWatch) { 
            nscoord maxWidth = (NS_UNCONSTRAINEDSIZE == availWidth) 
                                ? desiredSize.width : desiredSize.mMaximumWidth;
            // save the max element width and max width
            cellFrame->SetPass1MaxElementSize(desiredSize.width, *desiredSize.maxElementSize);
            if (desiredSize.maxElementSize->width > desiredSize.width) {
              NS_ASSERTION(PR_FALSE, "max element width exceeded desired width");
              desiredSize.width = desiredSize.maxElementSize->width;
            }
            cellFrame->SetMaximumWidth(maxWidth);
          }

          // allow the table to determine if/how the table needs to be rebalanced
          if (cellToWatch && needToNotifyTable) {
            needToNotifyTable = !tableFrame->CellChangedWidth(*cellFrame, oldMaxWidth, oldMaxElemWidth);
          }

          // If any of the cells are not complete, then we're not complete
          if (NS_FRAME_IS_NOT_COMPLETE(status)) {
            aStatus = NS_FRAME_NOT_COMPLETE;
          }
        }
        else { 
          nsSize priorSize = cellFrame->GetDesiredSize();
          desiredSize.width = priorSize.width;
          desiredSize.height = priorSize.height;

          // Because we may have moved the frame we need to make sure any views are
          // positioned properly. We have to do this, because any one of our parent
          // frames could have moved and we have no way of knowing...
          nsTableFrame::RePositionViews(aPresContext, kidFrame);
        }
  
        // Calculate the cell's actual size given its pass2 size. This function
        // takes into account the specified height (in the style), and any special
        // logic needed for backwards compatibility
        CalculateCellActualSize(kidFrame, desiredSize.width, 
                                desiredSize.height, availWidth);

        // height may have changed, adjust descent to absorb any excess difference
        nscoord ascent = cellFrame->GetDesiredAscent();
        nscoord descent = desiredSize.height - ascent;
        SetTallestCell(desiredSize.height, ascent, descent, tableFrame, cellFrame);

        // Place the child
        FinishReflowChild(kidFrame, aPresContext, desiredSize, x, 0, 0);
        x += desiredSize.width;  
      }
      else {// it's an unknown frame type, give it a generic reflow and ignore the results
        nsTableCellReflowState kidReflowState(aPresContext, aReflowState,
                                              kidFrame, nsSize(0,0), eReflowReason_Resize);
        nsHTMLReflowMetrics desiredSize(nsnull);
        nsReflowStatus  status;
        ReflowChild(kidFrame, aPresContext, desiredSize, kidReflowState, 0, 0, 0, status);
        kidFrame->DidReflow(aPresContext, NS_FRAME_REFLOW_FINISHED);
      }
    }
    else if (nsLayoutAtoms::tableCellFrame == frameType.get()) {
      // we need to account for the cell's width even if it isn't reflowed
      nsRect rect;
      kidFrame->GetRect(rect);
      x += rect.width;
    }

    kidFrame = iter.Next(); // Get the next child
    // if this was the last child, and it had a colspan>1, add in the cellSpacing for the colspan
    // if the last kid wasn't a colspan, then we still have the colspan of the last real cell
    if (!kidFrame && (cellColSpan > 1))
      x += cellSpacingX;
  }

  // just set our width to what was available. The table will calculate the width and not use our value.
  aDesiredSize.width = aReflowState.availableWidth;
  CalcTallestCell();
  aDesiredSize.height = GetTallestCell();  

  return rv;
}

NS_METHOD nsTableRowFrame::IncrementalReflow(nsIPresContext*          aPresContext,
                                             nsHTMLReflowMetrics&     aDesiredSize,
                                             const nsHTMLReflowState& aReflowState,
                                             nsTableFrame&            aTableFrame,
                                             nsReflowStatus&          aStatus)
{
  nsresult rv = NS_OK;
  CalcTallestCell(); // need to recalculate it based on last reflow sizes
 
  // determine if this frame is the target or not
  nsIFrame* target = nsnull;
  rv = aReflowState.reflowCommand->GetTarget(target);
  if (target) {
    if (this == target)
      rv = IR_TargetIsMe(aPresContext, aDesiredSize, aReflowState, aTableFrame, aStatus);
    else {
      // Get the next frame in the reflow chain
      nsIFrame* nextFrame;
      aReflowState.reflowCommand->GetNext(nextFrame);
      rv = IR_TargetIsChild(aPresContext, aDesiredSize, aReflowState, aTableFrame, aStatus, nextFrame);
    }
  }
  return rv;
}

NS_METHOD 
nsTableRowFrame::IR_TargetIsMe(nsIPresContext*          aPresContext,
                               nsHTMLReflowMetrics&     aDesiredSize,
                               const nsHTMLReflowState& aReflowState,
                               nsTableFrame&            aTableFrame,
                               nsReflowStatus&          aStatus)
{
  nsresult rv = NS_FRAME_COMPLETE;

  nsIReflowCommand::ReflowType type;
  aReflowState.reflowCommand->GetType(type);
  switch (type) {
    case nsIReflowCommand::ReflowDirty: {
      // Reflow the dirty child frames. Typically this is newly added frames.
      rv = ReflowChildren(aPresContext, aDesiredSize, aReflowState, aTableFrame, aStatus, PR_TRUE);
      break;
    }
    case nsIReflowCommand::StyleChanged :
      rv = IR_StyleChanged(aPresContext, aDesiredSize, aReflowState, aTableFrame, aStatus);
      break;
    case nsIReflowCommand::ContentChanged :
      NS_ASSERTION(PR_FALSE, "illegal reflow type: ContentChanged");
      rv = NS_ERROR_ILLEGAL_VALUE;
      break;
    default:
      NS_NOTYETIMPLEMENTED("unexpected reflow command type");
      rv = NS_ERROR_NOT_IMPLEMENTED;
      break;
  }

  return rv;
}

NS_METHOD 
nsTableRowFrame::IR_StyleChanged(nsIPresContext*          aPresContext,
                                 nsHTMLReflowMetrics&     aDesiredSize,
                                 const nsHTMLReflowState& aReflowState,
                                 nsTableFrame&            aTableFrame,
                                 nsReflowStatus&          aStatus)
{
  nsresult rv = NS_OK;
  // we presume that all the easy optimizations were done in the nsHTMLStyleSheet before we were called here
  // XXX: we can optimize this when we know which style attribute changed
  aTableFrame.SetNeedStrategyInit(PR_TRUE);
  return rv;
}

NS_METHOD 
nsTableRowFrame::IR_TargetIsChild(nsIPresContext*          aPresContext,
                                  nsHTMLReflowMetrics&     aDesiredSize,
                                  const nsHTMLReflowState& aReflowState,
                                  nsTableFrame&            aTableFrame,
                                  nsReflowStatus&          aStatus,
                                  nsIFrame*                aNextFrame)

{
  if (!aNextFrame) return NS_ERROR_NULL_POINTER;
  nsresult rv = NS_OK;

  PRBool isAutoLayout = aTableFrame.IsAutoLayout();
  const nsStyleDisplay *childDisplay;
  aNextFrame->GetStyleData(eStyleStruct_Display, ((const nsStyleStruct *&)childDisplay));
  if (NS_STYLE_DISPLAY_TABLE_CELL == childDisplay->mDisplay) {
    nsTableCellFrame* cellFrame = (nsTableCellFrame*)aNextFrame;
    // Get the x coord of the cell
    nsPoint cellOrigin;
    cellFrame->GetOrigin(cellOrigin);

    // At this point, we know the column widths. Compute the cell available width
    PRInt32 cellColIndex;
    cellFrame->GetColIndex(cellColIndex);
    PRInt32 cellColSpan = aTableFrame.GetEffectiveColSpan(*cellFrame);
    nscoord cellSpacingX = aTableFrame.GetCellSpacingX();

    nscoord cellAvailWidth = CalcCellAvailWidth(aTableFrame, *cellFrame, cellSpacingX);

    // Always let the cell be as high as it wants. We ignore the height that's
    // passed in and always place the entire row. Let the row group decide
    // whether we fit or wehther the entire row is pushed
    nsSize  cellAvailSize(cellAvailWidth, NS_UNCONSTRAINEDSIZE);

    // Pass along the reflow command
    nsSize              kidMaxElementSize;
    // Unless this is a fixed-layout table, then have the cell incrementally
    // update its maximum width. 
    nsHTMLReflowMetrics cellMet(&kidMaxElementSize, isAutoLayout ? 
                                                    NS_REFLOW_CALC_MAX_WIDTH : 0);
    nsTableCellReflowState kidRS(aPresContext, aReflowState, aNextFrame, cellAvailSize);

    // Remember the current desired size, we'll need it later
    nsSize  oldCellMinSize      = cellFrame->GetPass1MaxElementSize();
    nscoord oldCellMaximumWidth = cellFrame->GetMaximumWidth();
    nsSize  oldCellDesSize      = cellFrame->GetDesiredSize();
    nscoord oldCellDesAscent    = cellFrame->GetDesiredAscent();
    nscoord oldCellDesDescent   = oldCellDesSize.height - oldCellDesAscent;
    
    // Reflow the cell passing it the incremental reflow command. We can't pass
    // in a max width of NS_UNCONSTRAINEDSIZE, because the max width must match
    // the width of the previous reflow...
    rv = ReflowChild(aNextFrame, aPresContext, cellMet, kidRS,
                     cellOrigin.x, 0, 0, aStatus);
    nsSize initCellDesSize(cellMet.width, cellMet.height);
    nscoord initCellDesAscent = cellMet.ascent;
    nscoord initCellDesDescent = cellMet.descent;
    
    // cache the max-elem and maximum widths
    cellFrame->SetPass1MaxElementSize(cellMet.width, kidMaxElementSize);
    cellFrame->SetMaximumWidth(cellMet.mMaximumWidth);

    // Calculate the cell's actual size given its pass2 size. This function
    // takes into account the specified height (in the style), and any special
    // logic needed for backwards compatibility
    CalculateCellActualSize(aNextFrame, cellMet.width, cellMet.height, cellAvailWidth);

    // height may have changed, adjust descent to absorb any excess difference
    cellMet.descent = cellMet.height - cellMet.ascent;

    // if the cell got shorter and it may have been the tallest, recalc the tallest cell
    PRBool tallestCellGotShorter = PR_FALSE;
    PRBool hasVerticalAlignBaseline = cellFrame->HasVerticalAlignBaseline();
    if (!hasVerticalAlignBaseline) { 
      // only the height matters
      tallestCellGotShorter = 
        TallestCellGotShorter(oldCellDesSize.height, cellMet.height, mTallestCell);
    }
    else {
      // the ascent matters
      tallestCellGotShorter = 
        TallestCellGotShorter(oldCellDesAscent, cellMet.ascent, mMaxCellAscent);
      // the descent of cells without rowspan also matters
      if (!tallestCellGotShorter) {
        PRInt32 rowSpan = aTableFrame.GetEffectiveRowSpan(*cellFrame);
        if (rowSpan == 1) {
         tallestCellGotShorter = 
           TallestCellGotShorter(oldCellDesAscent, cellMet.descent, mMaxCellDescent);
        }
      }
    }
    if (tallestCellGotShorter) {
      CalcTallestCell();
    }
    else {
      SetTallestCell(cellMet.height, cellMet.ascent, cellMet.descent, &aTableFrame, cellFrame);
    }

    // if the cell's desired size didn't changed, our height is unchanged
    aDesiredSize.mNothingChanged = PR_FALSE;
    PRInt32 rowSpan = aTableFrame.GetEffectiveRowSpan(*cellFrame);
    if ((initCellDesSize.width  == oldCellDesSize.width)  &&
        (initCellDesSize.height == oldCellDesSize.height) &&
        (oldCellMaximumWidth    == cellMet.mMaximumWidth)) {
      if (!hasVerticalAlignBaseline) { // only the cell's height matters
        aDesiredSize.mNothingChanged = PR_TRUE;
      }
      else { // cell's ascent and cell's descent matter
        if (initCellDesAscent == oldCellDesAscent) {
          if ((rowSpan == 1) && (initCellDesDescent == oldCellDesDescent)) {
            aDesiredSize.mNothingChanged = PR_TRUE;
          }
        }
      }
    }
    aDesiredSize.height = (aDesiredSize.mNothingChanged) ? mRect.height : GetTallestCell();
    if (1 == rowSpan) {
      cellMet.height = aDesiredSize.height;
    }
    else {
      nscoord heightOfRows = aDesiredSize.height + GetHeightOfRowsSpannedBelowFirst(*cellFrame, aTableFrame); 
      cellMet.height = PR_MAX(cellMet.height, heightOfRows); 
      // XXX need to check what happens when this height differs from height of the cell's previous mRect.height
    }

    // Now place the child
    FinishReflowChild(aNextFrame, aPresContext, cellMet, cellOrigin.x, 0, 0);

    // Notify the table if the cell width changed so it can decide whether to rebalance
    if (!aDesiredSize.mNothingChanged) {
      aTableFrame.CellChangedWidth(*cellFrame, oldCellMinSize.width, oldCellMaximumWidth); 
    } 

    // Return our desired size. Note that our desired width is just whatever width
    // we were given by the row group frame
    aDesiredSize.width  = aReflowState.availableWidth;
    if (!aDesiredSize.mNothingChanged) {
      if (aDesiredSize.height == mRect.height) { // our height didn't change
        cellFrame->VerticallyAlignChild(aPresContext, aReflowState, mMaxCellAscent);
        nsRect dirtyRect;
        cellFrame->GetRect(dirtyRect);
        dirtyRect.height = mRect.height;
        Invalidate(aPresContext, dirtyRect);
      }
    }
  }
  else
  { // pass reflow to unknown frame child
    // aDesiredSize does not change
  }

  // When returning whether we're complete we need to look at each of our cell
  // frames. If any of them has a continuing frame, then we're not complete. We
  // can't just return the status of the cell frame we just reflowed...
  aStatus = NS_FRAME_COMPLETE;
  if (mNextInFlow) {
    for (nsIFrame* cell = mFrames.FirstChild(); cell; cell->GetNextSibling(&cell)) {
      nsIFrame* contFrame;
  
      cell->GetNextInFlow(&contFrame);
      if (contFrame) {
        aStatus =  NS_FRAME_NOT_COMPLETE;
        break;
      }
    }
  }
  return rv;
}


/** Layout the entire row.
  * This method stacks cells horizontally according to HTML 4.0 rules.
  */
NS_METHOD
nsTableRowFrame::Reflow(nsIPresContext*          aPresContext,
                        nsHTMLReflowMetrics&     aDesiredSize,
                        const nsHTMLReflowState& aReflowState,
                        nsReflowStatus&          aStatus)
{
  DO_GLOBAL_REFLOW_COUNT("nsTableRowFrame", aReflowState.reason);
#if defined DEBUG_TABLE_REFLOW | DEBUG_TABLE_REFLOW_TIMING
  nsTableFrame::DebugReflow(this, (nsHTMLReflowState&)aReflowState);
#endif
  nsresult rv = NS_OK;

  nsTableFrame* tableFrame = nsnull;
  rv = nsTableFrame::GetTableFrame(this, tableFrame);
  if (!tableFrame) return NS_ERROR_NULL_POINTER;

  switch (aReflowState.reason) {
  case eReflowReason_Initial:
    rv = ReflowChildren(aPresContext, aDesiredSize, aReflowState, *tableFrame, aStatus, PR_FALSE);
#ifdef WHY
    if (!tableFrame->IsAutoLayout()) {
      // this resize reflow is necessary to place the cells correctly in the case of rowspans and colspans.  
      // It is very efficient.  It does not actually need to pass a reflow down to the cells.
      nsSize  availSpace(aReflowState.availableWidth, aReflowState.availableHeight);
      nsHTMLReflowState  resizeReflowState(aPresContext,
                                           (const nsHTMLReflowState&)(*(aReflowState.parentReflowState)),
                                           (nsIFrame *)this,
                                           availSpace,
                                           eReflowReason_Resize);
      RowReflowState rowResizeReflowState(resizeReflowState, tableFrame);
      rv = ReflowChildren(aPresContext, aDesiredSize, rowResizeReflowState, aStatus);
    }
#endif
    //GetMinRowSpan(tableFrame);
    //FixMinCellHeight(tableFrame);
    aStatus = NS_FRAME_COMPLETE;
    break;

  case eReflowReason_Resize:
  case eReflowReason_StyleChange:
    rv = ReflowChildren(aPresContext, aDesiredSize, aReflowState, *tableFrame, aStatus, PR_FALSE);
    break;

  case eReflowReason_Incremental:
    rv = IncrementalReflow(aPresContext, aDesiredSize, aReflowState, *tableFrame, aStatus);
    break;
  }

  // just set our width to what was available. The table will calculate the width and not use our value.
  aDesiredSize.width = aReflowState.availableWidth;

#if defined DEBUG_TABLE_REFLOW | DEBUG_TABLE_REFLOW_TIMING
  nsTableFrame::DebugReflow(this, (nsHTMLReflowState&)aReflowState, &aDesiredSize, aStatus);
#endif
  return rv;
}

/* we overload this here because rows have children that can span outside of themselves.
 * so the default "get the child rect, see if it contains the event point" action isn't
 * sufficient.  We have to ask the row if it has a child that contains the point.
 */
PRBool 
nsTableRowFrame::Contains(nsIPresContext* aPresContext, 
                          const nsPoint&  aPoint)
{
  PRBool result = PR_FALSE;
  // first, check the row rect and see if the point is in their
  if (mRect.Contains(aPoint)) {
    result = PR_TRUE;
  }
  // if that fails, check the cells, they might span outside the row rect
  else {
    nsIFrame* kid;
    FirstChild(aPresContext, nsnull, &kid);
    while (nsnull != kid) {
      nsRect kidRect;
      kid->GetRect(kidRect);
      nsPoint point(aPoint);
      point.MoveBy(-mRect.x, -mRect.y); // offset the point to check by the row container
      if (kidRect.Contains(point)) {
        result = PR_TRUE;
        break;
      }
      kid->GetNextSibling(&kid);
    }
  }
  return result;
}

/**
 * This function is called by the row group frame's SplitRowGroup() code when
 * pushing a row frame that has cell frames that span into it. The cell frame
 * should be reflowed with the specified height
 */
nscoord 
nsTableRowFrame::ReflowCellFrame(nsIPresContext*          aPresContext,
                                 const nsHTMLReflowState& aReflowState,
                                 nsTableCellFrame*        aCellFrame,
                                 nscoord                  aAvailableHeight,
                                 nsReflowStatus&          aStatus)
{
  // Reflow the cell frame with the specified height. Use the existing width
  nsSize  cellSize;
  aCellFrame->GetSize(cellSize);
  
  nsSize  availSize(cellSize.width, aAvailableHeight);
  nsTableCellReflowState cellReflowState(aPresContext, aReflowState, aCellFrame, availSize,
                                         eReflowReason_Resize);
  nsHTMLReflowMetrics desiredSize(nsnull);

  ReflowChild(aCellFrame, aPresContext, desiredSize, cellReflowState,
              0, 0, NS_FRAME_NO_MOVE_FRAME, aStatus);
  aCellFrame->SizeTo(aPresContext, cellSize.width, aAvailableHeight);

  // XXX What happens if this cell has 'vertical-align: baseline' ?
  // XXX Why is it assumed that the cell's ascent hasn't changed ?
  aCellFrame->VerticallyAlignChild(aPresContext, aReflowState, mMaxCellAscent);
  aCellFrame->DidReflow(aPresContext, NS_FRAME_REFLOW_FINISHED);

  return desiredSize.height;
}

/**
 * These 3 functions are called by the row group frame's SplitRowGroup() code when
 * it creates a continuing cell frame and wants to insert it into the row's child list
 */
void 
nsTableRowFrame::InsertCellFrame(nsTableCellFrame* aFrame,
                                 nsTableCellFrame* aPrevSibling)
{
  mFrames.InsertFrame(nsnull, aPrevSibling, aFrame);
  aFrame->SetParent(this);
}

void 
nsTableRowFrame::InsertCellFrame(nsTableCellFrame* aFrame,
                                 PRInt32           aColIndex)
{
  // Find the cell frame where col index < aColIndex
  nsTableCellFrame* priorCell = nsnull;
  for (nsIFrame* child = mFrames.FirstChild(); child; child->GetNextSibling(&child)) {
    nsCOMPtr<nsIAtom> frameType;
    child->GetFrameType(getter_AddRefs(frameType));
    if (nsLayoutAtoms::tableCellFrame != frameType.get()) {
      nsTableCellFrame* cellFrame = (nsTableCellFrame*)child;
      PRInt32 colIndex;
      cellFrame->GetColIndex(colIndex);
      if (colIndex < aColIndex) {
        priorCell = cellFrame;
      }
      else break;
    }
  }
  InsertCellFrame(aFrame, priorCell);
}

void 
nsTableRowFrame::RemoveCellFrame(nsTableCellFrame* aFrame)
{
  mFrames.RemoveFrame(aFrame);
}

NS_IMETHODIMP
nsTableRowFrame::GetFrameType(nsIAtom** aType) const
{
  NS_PRECONDITION(nsnull != aType, "null OUT parameter pointer");
  *aType = nsLayoutAtoms::tableRowFrame; 
  NS_ADDREF(*aType);
  return NS_OK;
}


/* ----- global methods ----- */

nsresult 
NS_NewTableRowFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame)
{
  NS_PRECONDITION(aNewFrame, "null OUT ptr");
  if (nsnull == aNewFrame) {
    return NS_ERROR_NULL_POINTER;
  }
  nsTableRowFrame* it = new (aPresShell) nsTableRowFrame;
  if (nsnull == it) {
    return NS_ERROR_OUT_OF_MEMORY;
  }
  *aNewFrame = it;
  return NS_OK;
}

#ifdef DEBUG
NS_IMETHODIMP
nsTableRowFrame::GetFrameName(nsString& aResult) const
{
  return MakeFrameName("TableRow", aResult);
}

NS_IMETHODIMP
nsTableRowFrame::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
{
  if (!aResult) {
    return NS_ERROR_NULL_POINTER;
  }
  PRUint32 sum = sizeof(*this);
  *aResult = sum;
  return NS_OK;
}
#endif