layout/tables/nsTableCellFrame.cpp
author Matt Woodrow <mwoodrow@mozilla.com>
Mon, 20 May 2019 23:16:09 +0000
changeset 474634 69b049f546226b6bcc288986bbf60d792f01bf8f
parent 474633 df9a4342bf9750ad45219104bfd25674260f6080
child 474635 1c9357112b30b32385452b1f8794980fd72fc4b4
permissions -rw-r--r--
Bug 1409114 - Part 8: Create column and column group background display items as part of the cell's BuildDisplayList. r=dbaron This is the main performance improvement, and means that we no longer have to iterate all the cells for each column. It has a couple of behaviour changes: The first is that we no longer apply stacking context effects (like opacity) to column and column group backgrounds. I believe this is correct as per both CSS2.1 Appendix E, and css-tables-3 (quoted in nsTableColFrame::BuildDisplayList). This matches the behaviour of blink and WebKit. We also previously created items in column,row ordering, whereas now they will be in row,column. In cases where two cells overlap (using rowspan and colspan to extend multiple neighbours in to the same place) this can render backgrounds in a different order, but the new behaviour matches blink and WebKit. Differential Revision: https://phabricator.services.mozilla.com/D29280

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsTableCellFrame.h"

#include "gfxContext.h"
#include "gfxUtils.h"
#include "mozilla/ComputedStyle.h"
#include "mozilla/PresShell.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/gfx/Helpers.h"
#include "nsTableFrame.h"
#include "nsTableColFrame.h"
#include "nsTableRowFrame.h"
#include "nsTableRowGroupFrame.h"
#include "nsStyleConsts.h"
#include "nsPresContext.h"
#include "nsCSSRendering.h"
#include "nsIContent.h"
#include "nsGenericHTMLElement.h"
#include "nsAttrValueInlines.h"
#include "nsHTMLParts.h"
#include "nsGkAtoms.h"
#include "nsIServiceManager.h"
#include "nsDisplayList.h"
#include "nsLayoutUtils.h"
#include "nsTextFrame.h"
#include "FrameLayerBuilder.h"
#include <algorithm>

// TABLECELL SELECTION
#include "nsFrameSelection.h"
#include "mozilla/LookAndFeel.h"

using namespace mozilla;
using namespace mozilla::gfx;
using namespace mozilla::image;

class nsDisplayTableCellSelection final : public nsPaintedDisplayItem {
 public:
  nsDisplayTableCellSelection(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
      : nsPaintedDisplayItem(aBuilder, aFrame) {
    MOZ_COUNT_CTOR(nsDisplayTableCellSelection);
  }
#ifdef NS_BUILD_REFCNT_LOGGING
  virtual ~nsDisplayTableCellSelection() {
    MOZ_COUNT_DTOR(nsDisplayTableCellSelection);
  }
#endif

  void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override {
    static_cast<nsTableCellFrame*>(mFrame)->DecorateForSelection(
        aCtx->GetDrawTarget(), ToReferenceFrame());
  }
  NS_DISPLAY_DECL_NAME("TableCellSelection", TYPE_TABLE_CELL_SELECTION)

  bool CreateWebRenderCommands(
      mozilla::wr::DisplayListBuilder& aBuilder,
      mozilla::wr::IpcResourceUpdateQueue& aResources,
      const StackingContextHelper& aSc,
      mozilla::layers::RenderRootStateManager* aManager,
      nsDisplayListBuilder* aDisplayListBuilder) override {
    RefPtr<nsFrameSelection> frameSelection =
        mFrame->PresShell()->FrameSelection();
    if (frameSelection->GetTableCellSelection()) {
      return false;
    }

    return true;
  }
};

nsTableCellFrame::nsTableCellFrame(ComputedStyle* aStyle,
                                   nsTableFrame* aTableFrame, ClassID aID)
    : nsContainerFrame(aStyle, aTableFrame->PresContext(), aID),
      mDesiredSize(aTableFrame->GetWritingMode()) {
  mColIndex = 0;
  mPriorAvailISize = 0;

  SetContentEmpty(false);
  SetHasPctOverBSize(false);
}

nsTableCellFrame::~nsTableCellFrame() {}

NS_IMPL_FRAMEARENA_HELPERS(nsTableCellFrame)

void nsTableCellFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
                            nsIFrame* aPrevInFlow) {
  // Let the base class do its initialization
  nsContainerFrame::Init(aContent, aParent, aPrevInFlow);

  if (HasAnyStateBits(NS_FRAME_FONT_INFLATION_CONTAINER)) {
    AddStateBits(NS_FRAME_FONT_INFLATION_FLOW_ROOT);
  }

  if (aPrevInFlow) {
    // Set the column index
    nsTableCellFrame* cellFrame = (nsTableCellFrame*)aPrevInFlow;
    uint32_t colIndex = cellFrame->ColIndex();
    SetColIndex(colIndex);
  } else {
    // Although the spec doesn't say that writing-mode is not applied to
    // table-cells, we still override style value here because we want to
    // make effective writing mode of table structure frames consistent
    // within a table. The content inside table cells is reflowed by an
    // anonymous block, hence their writing mode is not affected.
    mWritingMode = GetTableFrame()->GetWritingMode();
  }
}

void nsTableCellFrame::DestroyFrom(nsIFrame* aDestructRoot,
                                   PostDestroyData& aPostDestroyData) {
  if (HasAnyStateBits(NS_FRAME_CAN_HAVE_ABSPOS_CHILDREN)) {
    nsTableFrame::UnregisterPositionedTablePart(this, aDestructRoot);
  }

  nsContainerFrame::DestroyFrom(aDestructRoot, aPostDestroyData);
}

// nsIPercentBSizeObserver methods

void nsTableCellFrame::NotifyPercentBSize(const ReflowInput& aReflowInput) {
  // ReflowInput ensures the mCBReflowInput of blocks inside a
  // cell is the cell frame, not the inner-cell block, and that the
  // containing block of an inner table is the containing block of its
  // table wrapper.
  // XXXldb Given the now-stricter |NeedsToObserve|, many if not all of
  // these tests are probably unnecessary.

  // Maybe the cell reflow input; we sure if we're inside the |if|.
  const ReflowInput* cellRI = aReflowInput.mCBReflowInput;

  if (cellRI && cellRI->mFrame == this &&
      (cellRI->ComputedBSize() == NS_UNCONSTRAINEDSIZE ||
       cellRI->ComputedBSize() == 0)) {  // XXXldb Why 0?
    // This is a percentage bsize on a frame whose percentage bsizes
    // are based on the bsize of the cell, since its containing block
    // is the inner cell frame.

    // We'll only honor the percent bsize if sibling-cells/ancestors
    // have specified/pct bsize. (Also, siblings only count for this if
    // both this cell and the sibling cell span exactly 1 row.)

    if (nsTableFrame::AncestorsHaveStyleBSize(*cellRI) ||
        (GetTableFrame()->GetEffectiveRowSpan(*this) == 1 &&
         cellRI->mParentReflowInput->mFrame->HasAnyStateBits(
             NS_ROW_HAS_CELL_WITH_STYLE_BSIZE))) {
      for (const ReflowInput* rs = aReflowInput.mParentReflowInput;
           rs != cellRI; rs = rs->mParentReflowInput) {
        rs->mFrame->AddStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE);
      }

      nsTableFrame::RequestSpecialBSizeReflow(*cellRI);
    }
  }
}

// The cell needs to observe its block and things inside its block but nothing
// below that
bool nsTableCellFrame::NeedsToObserve(const ReflowInput& aReflowInput) {
  const ReflowInput* rs = aReflowInput.mParentReflowInput;
  if (!rs) return false;
  if (rs->mFrame == this) {
    // We always observe the child block.  It will never send any
    // notifications, but we need this so that the observer gets
    // propagated to its kids.
    return true;
  }
  rs = rs->mParentReflowInput;
  if (!rs) {
    return false;
  }

  // We always need to let the percent bsize observer be propagated
  // from a table wrapper frame to an inner table frame.
  LayoutFrameType fType = aReflowInput.mFrame->Type();
  if (fType == LayoutFrameType::Table) {
    return true;
  }

  // We need the observer to be propagated to all children of the cell
  // (i.e., children of the child block) in quirks mode, but only to
  // tables in standards mode.
  // XXX This may not be true in the case of orthogonal flows within
  // the cell (bug 1174711 comment 8); we may need to observe isizes
  // instead of bsizes for orthogonal children.
  return rs->mFrame == this &&
         (PresContext()->CompatibilityMode() == eCompatibility_NavQuirks ||
          fType == LayoutFrameType::TableWrapper);
}

nsresult nsTableCellFrame::AttributeChanged(int32_t aNameSpaceID,
                                            nsAtom* aAttribute,
                                            int32_t aModType) {
  // We need to recalculate in this case because of the nowrap quirk in
  // BasicTableLayoutStrategy
  if (aNameSpaceID == kNameSpaceID_None && aAttribute == nsGkAtoms::nowrap &&
      PresContext()->CompatibilityMode() == eCompatibility_NavQuirks) {
    PresShell()->FrameNeedsReflow(this, IntrinsicDirty::TreeChange,
                                  NS_FRAME_IS_DIRTY);
  }

  if (aAttribute == nsGkAtoms::rowspan || aAttribute == nsGkAtoms::colspan) {
    nsLayoutUtils::PostRestyleEvent(mContent->AsElement(), RestyleHint{0},
                                    nsChangeHint_UpdateTableCellSpans);
  }
  return NS_OK;
}

/* virtual */
void nsTableCellFrame::DidSetComputedStyle(ComputedStyle* aOldComputedStyle) {
  nsContainerFrame::DidSetComputedStyle(aOldComputedStyle);

  if (!aOldComputedStyle)  // avoid this on init
    return;

  nsTableFrame* tableFrame = GetTableFrame();
  if (tableFrame->IsBorderCollapse() &&
      tableFrame->BCRecalcNeeded(aOldComputedStyle, Style())) {
    uint32_t colIndex = ColIndex();
    uint32_t rowIndex = RowIndex();
    // row span needs to be clamped as we do not create rows in the cellmap
    // which do not have cells originating in them
    TableArea damageArea(colIndex, rowIndex, GetColSpan(),
                         std::min(static_cast<uint32_t>(GetRowSpan()),
                                  tableFrame->GetRowCount() - rowIndex));
    tableFrame->AddBCDamageArea(damageArea);
  }
}

#ifdef DEBUG
void nsTableCellFrame::AppendFrames(ChildListID aListID,
                                    nsFrameList& aFrameList) {
  MOZ_CRASH("unsupported operation");
}

void nsTableCellFrame::InsertFrames(ChildListID aListID, nsIFrame* aPrevFrame,
                                    nsFrameList& aFrameList) {
  MOZ_CRASH("unsupported operation");
}

void nsTableCellFrame::RemoveFrame(ChildListID aListID, nsIFrame* aOldFrame) {
  MOZ_CRASH("unsupported operation");
}
#endif

void nsTableCellFrame::SetColIndex(int32_t aColIndex) { mColIndex = aColIndex; }

/* virtual */
nsMargin nsTableCellFrame::GetUsedMargin() const {
  return nsMargin(0, 0, 0, 0);
}

// ASSURE DIFFERENT COLORS for selection
inline nscolor EnsureDifferentColors(nscolor colorA, nscolor colorB) {
  if (colorA == colorB) {
    nscolor res;
    res = NS_RGB(NS_GET_R(colorA) ^ 0xff, NS_GET_G(colorA) ^ 0xff,
                 NS_GET_B(colorA) ^ 0xff);
    return res;
  }
  return colorA;
}

void nsTableCellFrame::DecorateForSelection(DrawTarget* aDrawTarget,
                                            nsPoint aPt) {
  NS_ASSERTION(IsSelected(), "Should only be called for selected cells");
  int16_t displaySelection;
  nsPresContext* presContext = PresContext();
  displaySelection = DisplaySelection(presContext);
  if (displaySelection) {
    RefPtr<nsFrameSelection> frameSelection =
        presContext->PresShell()->FrameSelection();

    if (frameSelection->GetTableCellSelection()) {
      nscolor bordercolor;
      if (displaySelection == nsISelectionController::SELECTION_DISABLED) {
        bordercolor = NS_RGB(176, 176, 176);  // disabled color
      } else {
        bordercolor =
            LookAndFeel::GetColor(LookAndFeel::eColorID_TextSelectBackground);
      }
      nscoord threePx = nsPresContext::CSSPixelsToAppUnits(3);
      if ((mRect.width > threePx) && (mRect.height > threePx)) {
        // compare bordercolor to background-color
        bordercolor = EnsureDifferentColors(
            bordercolor, StyleBackground()->BackgroundColor(this));

        int32_t appUnitsPerDevPixel = PresContext()->AppUnitsPerDevPixel();
        Point devPixelOffset = NSPointToPoint(aPt, appUnitsPerDevPixel);

        AutoRestoreTransform autoRestoreTransform(aDrawTarget);
        aDrawTarget->SetTransform(
            aDrawTarget->GetTransform().PreTranslate(devPixelOffset));

        ColorPattern color(ToDeviceColor(bordercolor));

        nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);

        StrokeLineWithSnapping(nsPoint(onePixel, 0), nsPoint(mRect.width, 0),
                               appUnitsPerDevPixel, *aDrawTarget, color);
        StrokeLineWithSnapping(nsPoint(0, onePixel), nsPoint(0, mRect.height),
                               appUnitsPerDevPixel, *aDrawTarget, color);
        StrokeLineWithSnapping(nsPoint(onePixel, mRect.height),
                               nsPoint(mRect.width, mRect.height),
                               appUnitsPerDevPixel, *aDrawTarget, color);
        StrokeLineWithSnapping(nsPoint(mRect.width, onePixel),
                               nsPoint(mRect.width, mRect.height),
                               appUnitsPerDevPixel, *aDrawTarget, color);
        // middle
        nsRect r(onePixel, onePixel, mRect.width - onePixel,
                 mRect.height - onePixel);
        Rect devPixelRect =
            NSRectToSnappedRect(r, appUnitsPerDevPixel, *aDrawTarget);
        aDrawTarget->StrokeRect(devPixelRect, color);
        // shading
        StrokeLineWithSnapping(
            nsPoint(2 * onePixel, mRect.height - 2 * onePixel),
            nsPoint(mRect.width - onePixel, mRect.height - (2 * onePixel)),
            appUnitsPerDevPixel, *aDrawTarget, color);
        StrokeLineWithSnapping(
            nsPoint(mRect.width - (2 * onePixel), 2 * onePixel),
            nsPoint(mRect.width - (2 * onePixel), mRect.height - onePixel),
            appUnitsPerDevPixel, *aDrawTarget, color);
      }
    }
  }
}

ImgDrawResult nsTableCellFrame::PaintBackground(gfxContext& aRenderingContext,
                                                const nsRect& aDirtyRect,
                                                nsPoint aPt, uint32_t aFlags) {
  nsRect rect(aPt, GetSize());
  nsCSSRendering::PaintBGParams params =
      nsCSSRendering::PaintBGParams::ForAllLayers(*PresContext(), aDirtyRect,
                                                  rect, this, aFlags);
  return nsCSSRendering::PaintStyleImageLayer(params, aRenderingContext);
}

nsresult nsTableCellFrame::ProcessBorders(nsTableFrame* aFrame,
                                          nsDisplayListBuilder* aBuilder,
                                          const nsDisplayListSet& aLists) {
  const nsStyleBorder* borderStyle = StyleBorder();
  if (aFrame->IsBorderCollapse() || !borderStyle->HasBorder()) return NS_OK;

  if (!GetContentEmpty() ||
      StyleTableBorder()->mEmptyCells == NS_STYLE_TABLE_EMPTY_CELLS_SHOW) {
    aLists.BorderBackground()->AppendNewToTop<nsDisplayBorder>(aBuilder, this);
  }

  return NS_OK;
}

class nsDisplayTableCellBackground : public nsDisplayTableItem {
 public:
  nsDisplayTableCellBackground(nsDisplayListBuilder* aBuilder,
                               nsTableCellFrame* aFrame)
      : nsDisplayTableItem(aBuilder, aFrame) {
    MOZ_COUNT_CTOR(nsDisplayTableCellBackground);
  }
#ifdef NS_BUILD_REFCNT_LOGGING
  virtual ~nsDisplayTableCellBackground() {
    MOZ_COUNT_DTOR(nsDisplayTableCellBackground);
  }
#endif

  virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
                       HitTestState* aState,
                       nsTArray<nsIFrame*>* aOutFrames) override {
    aOutFrames->AppendElement(mFrame);
  }
  virtual void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
  virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder,
                           bool* aSnap) const override;
  NS_DISPLAY_DECL_NAME("TableCellBackground", TYPE_TABLE_CELL_BACKGROUND)
};

void nsDisplayTableCellBackground::Paint(nsDisplayListBuilder* aBuilder,
                                         gfxContext* aCtx) {
  ImgDrawResult result =
      static_cast<nsTableCellFrame*>(mFrame)->PaintBackground(
          *aCtx, GetPaintRect(), ToReferenceFrame(),
          aBuilder->GetBackgroundPaintFlags());

  nsDisplayTableItemGeometry::UpdateDrawResult(this, result);
}

nsRect nsDisplayTableCellBackground::GetBounds(nsDisplayListBuilder* aBuilder,
                                               bool* aSnap) const {
  // revert from nsDisplayTableItem's implementation ... cell backgrounds
  // don't overflow the cell
  return nsDisplayItem::GetBounds(aBuilder, aSnap);
}

void nsTableCellFrame::InvalidateFrame(uint32_t aDisplayItemKey,
                                       bool aRebuildDisplayItems) {
  nsIFrame::InvalidateFrame(aDisplayItemKey, aRebuildDisplayItems);
  if (GetTableFrame()->IsBorderCollapse()) {
    GetParent()->InvalidateFrameWithRect(
        GetVisualOverflowRect() + GetPosition(), aDisplayItemKey, false);
  }
}

void nsTableCellFrame::InvalidateFrameWithRect(const nsRect& aRect,
                                               uint32_t aDisplayItemKey,
                                               bool aRebuildDisplayItems) {
  nsIFrame::InvalidateFrameWithRect(aRect, aDisplayItemKey,
                                    aRebuildDisplayItems);
  // If we have filters applied that would affects our bounds, then
  // we get an inactive layer created and this is computed
  // within FrameLayerBuilder
  GetParent()->InvalidateFrameWithRect(aRect + GetPosition(), aDisplayItemKey,
                                       false);
}

bool nsTableCellFrame::ShouldPaintBordersAndBackgrounds() const {
  // If we're not visible, we don't paint.
  if (!StyleVisibility()->IsVisible()) {
    return false;
  }

  // Consider 'empty-cells', but only in separated borders mode.
  if (!GetContentEmpty()) {
    return true;
  }

  nsTableFrame* tableFrame = GetTableFrame();
  if (tableFrame->IsBorderCollapse()) {
    return true;
  }

  return StyleTableBorder()->mEmptyCells == NS_STYLE_TABLE_EMPTY_CELLS_SHOW;
}

bool nsTableCellFrame::ShouldPaintBackground(nsDisplayListBuilder* aBuilder) {
  return ShouldPaintBordersAndBackgrounds();
}

void nsTableCellFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
                                        const nsDisplayListSet& aLists) {
  DO_GLOBAL_REFLOW_COUNT_DSP("nsTableCellFrame");
  if (ShouldPaintBordersAndBackgrounds()) {
    // display outset box-shadows if we need to.
    bool hasBoxShadow = !StyleEffects()->mBoxShadow.IsEmpty();
    if (hasBoxShadow) {
      aLists.BorderBackground()->AppendNewToTop<nsDisplayBoxShadowOuter>(
          aBuilder, this);
    }

    nsRect bgRect = GetRectRelativeToSelf() + aBuilder->ToReferenceFrame(this);

    // display background if we need to.
    if (aBuilder->IsForEventDelivery() ||
        !StyleBackground()->IsTransparent(this) ||
        StyleDisplay()->HasAppearance()) {
      nsDisplayBackgroundImage::AppendBackgroundItemsToTop(
          aBuilder, this, bgRect, aLists.BorderBackground());
    }

    // display inset box-shadows if we need to.
    if (hasBoxShadow) {
      aLists.BorderBackground()->AppendNewToTop<nsDisplayBoxShadowInner>(
          aBuilder, this);
    }

    // display borders if we need to
    ProcessBorders(GetTableFrame(), aBuilder, aLists);

    // and display the selection border if we need to
    if (IsSelected()) {
      aLists.BorderBackground()->AppendNewToTop<nsDisplayTableCellSelection>(
          aBuilder, this);
    }

    // This can be null if display list building initiated in the middle
    // of the table, which can happen with background-clip:text and
    // -moz-element.
    nsDisplayTableBackgroundSet* backgrounds =
        aBuilder->GetTableBackgroundSet();
    if (backgrounds) {
      // Compute bgRect relative to reference frame, but using the
      // normal (without position:relative offsets) positions for the
      // cell, row and row group.
      bgRect = GetRectRelativeToSelf() + GetNormalPosition();

      nsTableRowFrame* row = GetTableRowFrame();
      bgRect += row->GetNormalPosition();

      nsTableRowGroupFrame* rowGroup = row->GetTableRowGroupFrame();
      bgRect += rowGroup->GetNormalPosition();

      bgRect += backgrounds->TableToReferenceFrame();

      // Create backgrounds items as needed for the column and column
      // group that this cell occupies.
      nsTableColFrame* col = backgrounds->GetColForIndex(ColIndex());
      nsDisplayBackgroundImage::AppendBackgroundItemsToTop(
          aBuilder, col, bgRect, backgrounds->ColBackgrounds(), false, nullptr,
          col->GetRectRelativeToSelf() + aBuilder->ToReferenceFrame(col), this);

      nsIFrame* colGroup = col->GetParent();
      nsDisplayBackgroundImage::AppendBackgroundItemsToTop(
          aBuilder, colGroup, bgRect, backgrounds->ColGroupBackgrounds(), false,
          nullptr,
          colGroup->GetRectRelativeToSelf() +
              aBuilder->ToReferenceFrame(colGroup),
          this);
    }
  }

  // the 'empty-cells' property has no effect on 'outline'
  DisplayOutline(aBuilder, aLists);

  nsIFrame* kid = mFrames.FirstChild();
  NS_ASSERTION(kid && !kid->GetNextSibling(),
               "Table cells should have just one child");
  // The child's background will go in our BorderBackground() list.
  // This isn't a problem since it won't have a real background except for
  // event handling. We do not call BuildDisplayListForNonBlockChildren
  // because that/ would put the child's background in the Content() list
  // which isn't right (e.g., would end up on top of our child floats for
  // event handling).
  BuildDisplayListForChild(aBuilder, kid, aLists);
}

nsIFrame::LogicalSides nsTableCellFrame::GetLogicalSkipSides(
    const ReflowInput* aReflowInput) const {
  if (MOZ_UNLIKELY(StyleBorder()->mBoxDecorationBreak ==
                   StyleBoxDecorationBreak::Clone)) {
    return LogicalSides();
  }

  LogicalSides skip;
  if (nullptr != GetPrevInFlow()) {
    skip |= eLogicalSideBitsBStart;
  }
  if (nullptr != GetNextInFlow()) {
    skip |= eLogicalSideBitsBEnd;
  }
  return skip;
}

/* virtual */
nsMargin nsTableCellFrame::GetBorderOverflow() { return nsMargin(0, 0, 0, 0); }

// Align the cell's child frame within the cell

void nsTableCellFrame::BlockDirAlignChild(WritingMode aWM, nscoord aMaxAscent) {
  /* It's the 'border-collapse' on the table that matters */
  LogicalMargin borderPadding = GetLogicalUsedBorderAndPadding(aWM);

  nscoord bStartInset = borderPadding.BStart(aWM);
  nscoord bEndInset = borderPadding.BEnd(aWM);

  nscoord bSize = BSize(aWM);
  nsIFrame* firstKid = mFrames.FirstChild();
  nsSize containerSize = mRect.Size();
  NS_ASSERTION(firstKid,
               "Frame construction error, a table cell always has "
               "an inner cell frame");
  LogicalRect kidRect = firstKid->GetLogicalRect(aWM, containerSize);
  nscoord childBSize = kidRect.BSize(aWM);

  // Vertically align the child
  nscoord kidBStart = 0;
  switch (GetVerticalAlign()) {
    case StyleVerticalAlignKeyword::Baseline:
      // Align the baselines of the child frame with the baselines of
      // other children in the same row which have 'vertical-align: baseline'
      kidBStart = bStartInset + aMaxAscent - GetCellBaseline();
      break;

    case StyleVerticalAlignKeyword::Top:
      // Align the top of the child frame with the top of the content area,
      kidBStart = bStartInset;
      break;

    case StyleVerticalAlignKeyword::Bottom:
      // Align the bottom of the child frame with the bottom of the content
      // area,
      kidBStart = bSize - childBSize - bEndInset;
      break;

    default:
    case StyleVerticalAlignKeyword::Middle:
      // Align the middle of the child frame with the middle of the content
      // area,
      kidBStart = (bSize - childBSize - bEndInset + bStartInset) / 2;
  }
  // If the content is larger than the cell bsize, align from bStartInset
  // (cell's content-box bstart edge).
  kidBStart = std::max(bStartInset, kidBStart);

  if (kidBStart != kidRect.BStart(aWM)) {
    // Invalidate at the old position first
    firstKid->InvalidateFrameSubtree();
  }

  firstKid->SetPosition(aWM, LogicalPoint(aWM, kidRect.IStart(aWM), kidBStart),
                        containerSize);
  ReflowOutput desiredSize(aWM);
  desiredSize.SetSize(aWM, GetLogicalSize(aWM));

  nsRect overflow(nsPoint(0, 0), GetSize());
  overflow.Inflate(GetBorderOverflow());
  desiredSize.mOverflowAreas.SetAllTo(overflow);
  ConsiderChildOverflow(desiredSize.mOverflowAreas, firstKid);
  FinishAndStoreOverflow(&desiredSize);
  if (kidBStart != kidRect.BStart(aWM)) {
    // Make sure any child views are correctly positioned. We know the inner
    // table cell won't have a view
    nsContainerFrame::PositionChildViews(firstKid);

    // Invalidate new overflow rect
    firstKid->InvalidateFrameSubtree();
  }
  if (HasView()) {
    nsContainerFrame::SyncFrameViewAfterReflow(PresContext(), this, GetView(),
                                               desiredSize.VisualOverflow(), 0);
  }
}

bool nsTableCellFrame::ComputeCustomOverflow(nsOverflowAreas& aOverflowAreas) {
  nsRect bounds(nsPoint(0, 0), GetSize());
  bounds.Inflate(GetBorderOverflow());

  aOverflowAreas.UnionAllWith(bounds);
  return nsContainerFrame::ComputeCustomOverflow(aOverflowAreas);
}

// Per CSS 2.1, we map 'sub', 'super', 'text-top', 'text-bottom',
// length, percentage, and calc() values to 'baseline'.
StyleVerticalAlignKeyword nsTableCellFrame::GetVerticalAlign() const {
  const StyleVerticalAlign& verticalAlign = StyleDisplay()->mVerticalAlign;
  if (verticalAlign.IsKeyword()) {
    auto value = verticalAlign.AsKeyword();
    if (value == StyleVerticalAlignKeyword::Top ||
        value == StyleVerticalAlignKeyword::Middle ||
        value == StyleVerticalAlignKeyword::Bottom) {
      return value;
    }
  }
  return StyleVerticalAlignKeyword::Baseline;
}

bool nsTableCellFrame::CellHasVisibleContent(nscoord height,
                                             nsTableFrame* tableFrame,
                                             nsIFrame* kidFrame) {
  // see  http://www.w3.org/TR/CSS21/tables.html#empty-cells
  if (height > 0) return true;
  if (tableFrame->IsBorderCollapse()) return true;
  for (nsIFrame* innerFrame : kidFrame->PrincipalChildList()) {
    LayoutFrameType frameType = innerFrame->Type();
    if (LayoutFrameType::Text == frameType) {
      nsTextFrame* textFrame = static_cast<nsTextFrame*>(innerFrame);
      if (textFrame->HasNoncollapsedCharacters()) return true;
    } else if (LayoutFrameType::Placeholder != frameType) {
      return true;
    } else {
      nsIFrame* floatFrame = nsLayoutUtils::GetFloatFromPlaceholder(innerFrame);
      if (floatFrame) return true;
    }
  }
  return false;
}

nscoord nsTableCellFrame::GetCellBaseline() const {
  // Ignore the position of the inner frame relative to the cell frame
  // since we want the position as though the inner were top-aligned.
  nsIFrame* inner = mFrames.FirstChild();
  nscoord borderPadding = GetUsedBorderAndPadding().top;
  nscoord result;
  if (nsLayoutUtils::GetFirstLineBaseline(GetWritingMode(), inner, &result))
    return result + borderPadding;
  return inner->GetContentRectRelativeToSelf().YMost() + borderPadding;
}

int32_t nsTableCellFrame::GetRowSpan() {
  int32_t rowSpan = 1;

  // Don't look at the content's rowspan if we're a pseudo cell
  if (!Style()->IsPseudoOrAnonBox()) {
    dom::Element* elem = mContent->AsElement();
    const nsAttrValue* attr = elem->GetParsedAttr(nsGkAtoms::rowspan);
    // Note that we don't need to check the tag name, because only table cells
    // (including MathML <mtd>) and table headers parse the "rowspan" attribute
    // into an integer.
    if (attr && attr->Type() == nsAttrValue::eInteger) {
      rowSpan = attr->GetIntegerValue();
    }
  }
  return rowSpan;
}

int32_t nsTableCellFrame::GetColSpan() {
  int32_t colSpan = 1;

  // Don't look at the content's colspan if we're a pseudo cell
  if (!Style()->IsPseudoOrAnonBox()) {
    dom::Element* elem = mContent->AsElement();
    const nsAttrValue* attr = elem->GetParsedAttr(
        MOZ_UNLIKELY(elem->IsMathMLElement()) ? nsGkAtoms::columnspan_
                                              : nsGkAtoms::colspan);
    // Note that we don't need to check the tag name, because only table cells
    // (including MathML <mtd>) and table headers parse the "colspan" attribute
    // into an integer.
    if (attr && attr->Type() == nsAttrValue::eInteger) {
      colSpan = attr->GetIntegerValue();
    }
  }
  return colSpan;
}

/* virtual */
nscoord nsTableCellFrame::GetMinISize(gfxContext* aRenderingContext) {
  nscoord result = 0;
  DISPLAY_MIN_INLINE_SIZE(this, result);

  nsIFrame* inner = mFrames.FirstChild();
  result = nsLayoutUtils::IntrinsicForContainer(aRenderingContext, inner,
                                                nsLayoutUtils::MIN_ISIZE);
  return result;
}

/* virtual */
nscoord nsTableCellFrame::GetPrefISize(gfxContext* aRenderingContext) {
  nscoord result = 0;
  DISPLAY_PREF_INLINE_SIZE(this, result);

  nsIFrame* inner = mFrames.FirstChild();
  result = nsLayoutUtils::IntrinsicForContainer(aRenderingContext, inner,
                                                nsLayoutUtils::PREF_ISIZE);
  return result;
}

/* virtual */ nsIFrame::IntrinsicISizeOffsetData
nsTableCellFrame::IntrinsicISizeOffsets(nscoord aPercentageBasis) {
  IntrinsicISizeOffsetData result =
      nsContainerFrame::IntrinsicISizeOffsets(aPercentageBasis);

  result.hMargin = 0;

  WritingMode wm = GetWritingMode();
  result.hBorder = GetBorderWidth(wm).IStartEnd(wm);

  return result;
}

#ifdef DEBUG
#  define PROBABLY_TOO_LARGE 1000000
static void DebugCheckChildSize(nsIFrame* aChild, ReflowOutput& aMet) {
  WritingMode wm = aMet.GetWritingMode();
  if ((aMet.ISize(wm) < 0) || (aMet.ISize(wm) > PROBABLY_TOO_LARGE)) {
    printf("WARNING: cell content %p has large inline size %d \n",
           static_cast<void*>(aChild), int32_t(aMet.ISize(wm)));
  }
}
#endif

// the computed bsize for the cell, which descendants use for percent bsize
// calculations it is the bsize (minus border, padding) of the cell's first in
// flow during its final reflow without an unconstrained bsize.
static nscoord CalcUnpaginatedBSize(nsTableCellFrame& aCellFrame,
                                    nsTableFrame& aTableFrame,
                                    nscoord aBlockDirBorderPadding) {
  const nsTableCellFrame* firstCellInFlow =
      static_cast<nsTableCellFrame*>(aCellFrame.FirstInFlow());
  nsTableFrame* firstTableInFlow =
      static_cast<nsTableFrame*>(aTableFrame.FirstInFlow());
  nsTableRowFrame* row =
      static_cast<nsTableRowFrame*>(firstCellInFlow->GetParent());
  nsTableRowGroupFrame* firstRGInFlow =
      static_cast<nsTableRowGroupFrame*>(row->GetParent());

  uint32_t rowIndex = firstCellInFlow->RowIndex();
  int32_t rowSpan = aTableFrame.GetEffectiveRowSpan(*firstCellInFlow);

  nscoord computedBSize =
      firstTableInFlow->GetRowSpacing(rowIndex, rowIndex + rowSpan - 1);
  computedBSize -= aBlockDirBorderPadding;
  uint32_t rowX;
  for (row = firstRGInFlow->GetFirstRow(), rowX = 0; row;
       row = row->GetNextRow(), rowX++) {
    if (rowX > rowIndex + rowSpan - 1) {
      break;
    } else if (rowX >= rowIndex) {
      computedBSize += row->GetUnpaginatedBSize();
    }
  }
  return computedBSize;
}

void nsTableCellFrame::Reflow(nsPresContext* aPresContext,
                              ReflowOutput& aDesiredSize,
                              const ReflowInput& aReflowInput,
                              nsReflowStatus& aStatus) {
  MarkInReflow();
  DO_GLOBAL_REFLOW_COUNT("nsTableCellFrame");
  DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, aStatus);
  MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");

  if (aReflowInput.mFlags.mSpecialBSizeReflow) {
    FirstInFlow()->AddStateBits(NS_TABLE_CELL_HAD_SPECIAL_REFLOW);
  }

  // see if a special bsize reflow needs to occur due to having a pct height
  nsTableFrame::CheckRequestSpecialBSizeReflow(aReflowInput);

  WritingMode wm = aReflowInput.GetWritingMode();
  LogicalSize availSize = aReflowInput.AvailableSize();

  LogicalMargin borderPadding = aReflowInput.ComputedLogicalPadding();
  LogicalMargin border = GetBorderWidth(wm);
  borderPadding += border;

  // reduce available space by insets, if we're in a constrained situation
  availSize.ISize(wm) -= borderPadding.IStartEnd(wm);
  if (NS_UNCONSTRAINEDSIZE != availSize.BSize(wm)) {
    availSize.BSize(wm) -= borderPadding.BStartEnd(wm);
  }

  // Try to reflow the child into the available space. It might not
  // fit or might need continuing.
  if (availSize.BSize(wm) < 0) {
    availSize.BSize(wm) = 1;
  }

  ReflowOutput kidSize(wm);
  kidSize.ClearSize();
  SetPriorAvailISize(aReflowInput.AvailableISize());
  nsIFrame* firstKid = mFrames.FirstChild();
  NS_ASSERTION(
      firstKid,
      "Frame construction error, a table cell always has an inner cell frame");
  nsTableFrame* tableFrame = GetTableFrame();

  if (aReflowInput.mFlags.mSpecialBSizeReflow) {
    const_cast<ReflowInput&>(aReflowInput)
        .SetComputedBSize(BSize(wm) - borderPadding.BStartEnd(wm));
    DISPLAY_REFLOW_CHANGE();
  } else if (aPresContext->IsPaginated()) {
    nscoord computedUnpaginatedBSize = CalcUnpaginatedBSize(
        (nsTableCellFrame&)*this, *tableFrame, borderPadding.BStartEnd(wm));
    if (computedUnpaginatedBSize > 0) {
      const_cast<ReflowInput&>(aReflowInput)
          .SetComputedBSize(computedUnpaginatedBSize);
      DISPLAY_REFLOW_CHANGE();
    }
  } else {
    SetHasPctOverBSize(false);
  }

  WritingMode kidWM = firstKid->GetWritingMode();
  ReflowInput kidReflowInput(aPresContext, aReflowInput, firstKid,
                             availSize.ConvertTo(kidWM, wm));

  // Don't be a percent height observer if we're in the middle of
  // special-bsize reflow, in case we get an accidental NotifyPercentBSize()
  // call (which we shouldn't honor during special-bsize reflow)
  if (!aReflowInput.mFlags.mSpecialBSizeReflow) {
    // mPercentBSizeObserver is for children of cells in quirks mode,
    // but only those than are tables in standards mode.  NeedsToObserve
    // will determine how far this is propagated to descendants.
    kidReflowInput.mPercentBSizeObserver = this;
  }
  // Don't propagate special bsize reflow input to our kids
  kidReflowInput.mFlags.mSpecialBSizeReflow = false;

  if (aReflowInput.mFlags.mSpecialBSizeReflow ||
      FirstInFlow()->HasAnyStateBits(NS_TABLE_CELL_HAD_SPECIAL_REFLOW)) {
    // We need to force the kid to have mBResize set if we've had a
    // special reflow in the past, since the non-special reflow needs to
    // resize back to what it was without the special bsize reflow.
    kidReflowInput.SetBResize(true);
  }

  nsSize containerSize = aReflowInput.ComputedSizeAsContainerIfConstrained();

  LogicalPoint kidOrigin(wm, borderPadding.IStart(wm),
                         borderPadding.BStart(wm));
  nsRect origRect = firstKid->GetRect();
  nsRect origVisualOverflow = firstKid->GetVisualOverflowRect();
  bool firstReflow = firstKid->HasAnyStateBits(NS_FRAME_FIRST_REFLOW);

  ReflowChild(firstKid, aPresContext, kidSize, kidReflowInput, wm, kidOrigin,
              containerSize, 0, aStatus);
  if (aStatus.IsOverflowIncomplete()) {
    // Don't pass OVERFLOW_INCOMPLETE through tables until they can actually
    // handle it
    // XXX should paginate overflow as overflow, but not in this patch (bug
    // 379349)
    aStatus.SetIncomplete();
    printf("Set table cell incomplete %p\n", static_cast<void*>(this));
  }

  // XXXbz is this invalidate actually needed, really?
  if (HasAnyStateBits(NS_FRAME_IS_DIRTY)) {
    InvalidateFrameSubtree();
  }

#ifdef DEBUG
  DebugCheckChildSize(firstKid, kidSize);
#endif

  // 0 dimensioned cells need to be treated specially in Standard/NavQuirks mode
  // see testcase "emptyCells.html"
  nsIFrame* prevInFlow = GetPrevInFlow();
  bool isEmpty;
  if (prevInFlow) {
    isEmpty = static_cast<nsTableCellFrame*>(prevInFlow)->GetContentEmpty();
  } else {
    isEmpty = !CellHasVisibleContent(kidSize.Height(), tableFrame, firstKid);
  }
  SetContentEmpty(isEmpty);

  // Place the child
  FinishReflowChild(firstKid, aPresContext, kidSize, &kidReflowInput, wm,
                    kidOrigin, containerSize, 0);

  if (tableFrame->IsBorderCollapse()) {
    nsTableFrame::InvalidateTableFrame(firstKid, origRect, origVisualOverflow,
                                       firstReflow);
  }
  // first, compute the bsize which can be set w/o being restricted by
  // available bsize
  LogicalSize cellSize(wm);
  cellSize.BSize(wm) = kidSize.BSize(wm);

  if (NS_UNCONSTRAINEDSIZE != cellSize.BSize(wm)) {
    cellSize.BSize(wm) += borderPadding.BStartEnd(wm);
  }

  // next determine the cell's isize
  cellSize.ISize(wm) = kidSize.ISize(
      wm);  // at this point, we've factored in the cell's style attributes

  // factor in border and padding
  if (NS_UNCONSTRAINEDSIZE != cellSize.ISize(wm)) {
    cellSize.ISize(wm) += borderPadding.IStartEnd(wm);
  }

  // set the cell's desired size and max element size
  aDesiredSize.SetSize(wm, cellSize);

  // the overflow area will be computed when BlockDirAlignChild() gets called

  if (aReflowInput.mFlags.mSpecialBSizeReflow) {
    if (aDesiredSize.BSize(wm) > BSize(wm)) {
      // set a bit indicating that the pct bsize contents exceeded
      // the height that they could honor in the pass 2 reflow
      SetHasPctOverBSize(true);
    }
    if (NS_UNCONSTRAINEDSIZE == aReflowInput.AvailableBSize()) {
      aDesiredSize.BSize(wm) = BSize(wm);
    }
  }

  // If our parent is in initial reflow, it'll handle invalidating our
  // entire overflow rect.
  if (!GetParent()->HasAnyStateBits(NS_FRAME_FIRST_REFLOW) &&
      nsSize(aDesiredSize.Width(), aDesiredSize.Height()) != mRect.Size()) {
    InvalidateFrame();
  }

  // remember the desired size for this reflow
  SetDesiredSize(aDesiredSize);

  // Any absolutely-positioned children will get reflowed in
  // nsFrame::FixupPositionedTableParts in another pass, so propagate our
  // dirtiness to them before our parent clears our dirty bits.
  PushDirtyBitToAbsoluteFrames();

  NS_FRAME_SET_TRUNCATION(aStatus, aReflowInput, aDesiredSize);
}

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

NS_QUERYFRAME_HEAD(nsTableCellFrame)
  NS_QUERYFRAME_ENTRY(nsTableCellFrame)
  NS_QUERYFRAME_ENTRY(nsITableCellLayout)
  NS_QUERYFRAME_ENTRY(nsIPercentBSizeObserver)
NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)

#ifdef ACCESSIBILITY
a11y::AccType nsTableCellFrame::AccessibleType() {
  return a11y::eHTMLTableCellType;
}
#endif

/* This is primarily for editor access via nsITableLayout */
NS_IMETHODIMP
nsTableCellFrame::GetCellIndexes(int32_t& aRowIndex, int32_t& aColIndex) {
  aRowIndex = RowIndex();
  aColIndex = mColIndex;
  return NS_OK;
}

nsTableCellFrame* NS_NewTableCellFrame(PresShell* aPresShell,
                                       ComputedStyle* aStyle,
                                       nsTableFrame* aTableFrame) {
  if (aTableFrame->IsBorderCollapse())
    return new (aPresShell) nsBCTableCellFrame(aStyle, aTableFrame);
  else
    return new (aPresShell) nsTableCellFrame(aStyle, aTableFrame);
}

NS_IMPL_FRAMEARENA_HELPERS(nsBCTableCellFrame)

LogicalMargin nsTableCellFrame::GetBorderWidth(WritingMode aWM) const {
  return LogicalMargin(aWM, StyleBorder()->GetComputedBorder());
}

void nsTableCellFrame::AppendDirectlyOwnedAnonBoxes(
    nsTArray<OwnedAnonBox>& aResult) {
  nsIFrame* kid = mFrames.FirstChild();
  MOZ_ASSERT(kid && !kid->GetNextSibling(),
             "Table cells should have just one child");
  aResult.AppendElement(OwnedAnonBox(kid));
}

#ifdef DEBUG_FRAME_DUMP
nsresult nsTableCellFrame::GetFrameName(nsAString& aResult) const {
  return MakeFrameName(NS_LITERAL_STRING("TableCell"), aResult);
}
#endif

// nsBCTableCellFrame

nsBCTableCellFrame::nsBCTableCellFrame(ComputedStyle* aStyle,
                                       nsTableFrame* aTableFrame)
    : nsTableCellFrame(aStyle, aTableFrame, kClassID) {
  mBStartBorder = mIEndBorder = mBEndBorder = mIStartBorder = 0;
}

nsBCTableCellFrame::~nsBCTableCellFrame() {}

/* virtual */
nsMargin nsBCTableCellFrame::GetUsedBorder() const {
  WritingMode wm = GetWritingMode();
  return GetBorderWidth(wm).GetPhysicalMargin(wm);
}

#ifdef DEBUG_FRAME_DUMP
nsresult nsBCTableCellFrame::GetFrameName(nsAString& aResult) const {
  return MakeFrameName(NS_LITERAL_STRING("BCTableCell"), aResult);
}
#endif

LogicalMargin nsBCTableCellFrame::GetBorderWidth(WritingMode aWM) const {
  int32_t d2a = PresContext()->AppUnitsPerDevPixel();
  return LogicalMargin(aWM, BC_BORDER_END_HALF_COORD(d2a, mBStartBorder),
                       BC_BORDER_START_HALF_COORD(d2a, mIEndBorder),
                       BC_BORDER_START_HALF_COORD(d2a, mBEndBorder),
                       BC_BORDER_END_HALF_COORD(d2a, mIStartBorder));
}

BCPixelSize nsBCTableCellFrame::GetBorderWidth(LogicalSide aSide) const {
  switch (aSide) {
    case eLogicalSideBStart:
      return BC_BORDER_END_HALF(mBStartBorder);
    case eLogicalSideIEnd:
      return BC_BORDER_START_HALF(mIEndBorder);
    case eLogicalSideBEnd:
      return BC_BORDER_START_HALF(mBEndBorder);
    default:
      return BC_BORDER_END_HALF(mIStartBorder);
  }
}

void nsBCTableCellFrame::SetBorderWidth(LogicalSide aSide, BCPixelSize aValue) {
  switch (aSide) {
    case eLogicalSideBStart:
      mBStartBorder = aValue;
      break;
    case eLogicalSideIEnd:
      mIEndBorder = aValue;
      break;
    case eLogicalSideBEnd:
      mBEndBorder = aValue;
      break;
    default:
      mIStartBorder = aValue;
  }
}

/* virtual */
nsMargin nsBCTableCellFrame::GetBorderOverflow() {
  WritingMode wm = GetWritingMode();
  int32_t d2a = PresContext()->AppUnitsPerDevPixel();
  LogicalMargin halfBorder(wm, BC_BORDER_START_HALF_COORD(d2a, mBStartBorder),
                           BC_BORDER_END_HALF_COORD(d2a, mIEndBorder),
                           BC_BORDER_END_HALF_COORD(d2a, mBEndBorder),
                           BC_BORDER_START_HALF_COORD(d2a, mIStartBorder));
  return halfBorder.GetPhysicalMargin(wm);
}

ImgDrawResult nsBCTableCellFrame::PaintBackground(gfxContext& aRenderingContext,
                                                  const nsRect& aDirtyRect,
                                                  nsPoint aPt,
                                                  uint32_t aFlags) {
  // make border-width reflect the half of the border-collapse
  // assigned border that's inside the cell
  WritingMode wm = GetWritingMode();
  nsMargin borderWidth = GetBorderWidth(wm).GetPhysicalMargin(wm);

  nsStyleBorder myBorder(*StyleBorder());

  NS_FOR_CSS_SIDES(side) {
    myBorder.SetBorderWidth(side, borderWidth.Side(side));
  }

  // bypassing nsCSSRendering::PaintBackground is safe because this kind
  // of frame cannot be used for the root element
  nsRect rect(aPt, GetSize());
  nsCSSRendering::PaintBGParams params =
      nsCSSRendering::PaintBGParams::ForAllLayers(*PresContext(), aDirtyRect,
                                                  rect, this, aFlags);
  return nsCSSRendering::PaintStyleImageLayerWithSC(params, aRenderingContext,
                                                    Style(), myBorder);
}