Let table rows and sections paint their backgrounds in proper paint phases

third_party/WebKit/Source/core/paint/TableSectionPainter.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/TableSectionPainter.h"
 
 #include "core/layout/LayoutTable.h"
 #include "core/layout/LayoutTableCell.h"
 #include "core/layout/LayoutTableCol.h"
 #include "core/layout/LayoutTableRow.h"
 #include "core/paint/BlockPainter.h"
 #include "core/paint/BoxClipper.h"
 #include "core/paint/LayoutObjectDrawingRecorder.h"
 #include "core/paint/ObjectPainter.h"
 #include "core/paint/PaintInfo.h"
 #include "core/paint/TableCellPainter.h"
 #include "core/paint/TableRowPainter.h"
 #include <algorithm>
 
 namespace blink {
 
 void TableSectionPainter::paint(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     ASSERT(!m_layoutTableSection.needsLayout());
     // avoid crashing on bugs that cause us to paint with dirty layout
     if (m_layoutTableSection.needsLayout())
         return;
 
-    // Table sections don't paint self background. The cells paint table section's background
-    // behind them when needed during PaintPhaseBlockBackground or PaintPhaseDescendantBlockBackgroundOnly.
-    if (paintInfo.phase == PaintPhaseSelfBlockBackgroundOnly)

[chrishtr, 2016/01/28 18:14:33]

How did this work? I don't see calls into table cells painting the background,
in the code before this patch. Is the comment
incorrect?

[Xianzhu, 2016/01/28 18:34:36]

This method is called from PaintLayerPainter::paintLayerContents() via
PaintLayerPainter::paintBackgroundForFragments() and LayoutObject::paint()
interface when the table cell is self painting layer. The comment is correct.

[chrishtr, 2016/01/28 18:53:26]

TableSectionPainter::paint is called from LayoutTableSection::paint. Did you
mean when the table section is self-painting?

-        return;
-
     unsigned totalRows = m_layoutTableSection.numRows();
     unsigned totalCols = m_layoutTableSection.table()->columns().size();
 
     if (!totalRows || !totalCols)
         return;
 
     LayoutPoint adjustedPaintOffset = paintOffset + m_layoutTableSection.location();
 
     if (paintInfo.phase != PaintPhaseSelfOutlineOnly) {
-        BoxClipper boxClipper(m_layoutTableSection, paintInfo, adjustedPaintOffset, ForceContentsClip);
+        Optional<BoxClipper> boxClipper;
+        if (paintInfo.phase != PaintPhaseSelfBlockBackgroundOnly)
+            boxClipper.emplace(m_layoutTableSection, paintInfo, adjustedPaintOffset, ForceContentsClip);
         paintObject(paintInfo, adjustedPaintOffset);
     }
 
     if (shouldPaintSelfOutline(paintInfo.phase))
         ObjectPainter(m_layoutTableSection).paintOutline(paintInfo, adjustedPaintOffset);
 }
 
 static inline bool compareCellPositions(LayoutTableCell* elem1, LayoutTableCell* elem2)
 {
     return elem1->rowIndex() < elem2->rowIndex();
@@ skipping 64 matching lines @@
         for (unsigned r = dirtiedRows.start(); r < dirtiedRows.end(); r++) {
             const LayoutTableRow* row = m_layoutTableSection.rowLayoutObjectAt(r);
             // TODO(wangxianzhu): This painting order is inconsistent with other outlines. crbug.com/577282.
             if (row && !row->hasSelfPaintingLayer())
                 TableRowPainter(*row).paintOutlineForRowIfNeeded(paintInfo, paintOffset);
             for (unsigned c = dirtiedColumns.start(); c < dirtiedColumns.end(); c++) {
                 const LayoutTableSection::CellStruct& current = m_layoutTableSection.cellAt(r, c);
                 const LayoutTableCell* cell = current.primaryCell();
                 if (!cell || (r > dirtiedRows.start() && m_layoutTableSection.primaryCellAt(r - 1, c) == cell) || (c > dirtiedColumns.start() && m_layoutTableSection.primaryCellAt(r, c - 1) == cell))
                     continue;
-                paintCell(*cell, paintInfoForCells, paintOffset);
+                paintCell(*cell, paintInfo.phase, paintInfoForCells, paintOffset);
             }
         }
     } else {
         // The overflowing cells should be scarce to avoid adding a lot of cells to the HashSet.
 #if ENABLE(ASSERT)
         unsigned totalRows = m_layoutTableSection.numRows();
         unsigned totalCols = m_layoutTableSection.table()->columns().size();
         ASSERT(overflowingCells.size() < totalRows * totalCols * gMaxAllowedOverflowingCellRatioForFastPaintPath);
 #endif
 
@@ skipping 26 matching lines @@
             }
         }
 
         // Sort the dirty cells by paint order.
         if (!overflowingCells.size())
             std::stable_sort(cells.begin(), cells.end(), compareCellPositions);
         else
             std::sort(cells.begin(), cells.end(), compareCellPositionsWithOverflowingCells);
 
         for (unsigned i = 0; i < cells.size(); ++i)
-            paintCell(*cells[i], paintInfoForCells, paintOffset);
+            paintCell(*cells[i], paintInfo.phase, paintInfoForCells, paintOffset);
     }
 }
 
-void TableSectionPainter::paintCell(const LayoutTableCell& cell, const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
+void TableSectionPainter::paintCell(const LayoutTableCell& cell, PaintPhase originalPaintPhase, const PaintInfo& paintInfoForCells, const LayoutPoint& paintOffset)
 {
     LayoutPoint cellPoint = m_layoutTableSection.flipForWritingModeForChild(&cell, paintOffset);
-    PaintPhase paintPhase = paintInfo.phase;
     const LayoutTableRow* row = toLayoutTableRow(cell.parent());
 
-    if (shouldPaintSelfBlockBackground(paintPhase)
-        && BlockPainter(cell).intersectsPaintRect(paintInfo, paintOffset + cell.location())) {
+    if (!BlockPainter(cell).intersectsPaintRect(paintInfoForCells, paintOffset + cell.location()))
+        return;
+
+    if (shouldPaintSelfBlockBackground(originalPaintPhase)) {
         // We need to handle painting a stack of backgrounds. This stack (from bottom to top) consists of
         // the column group, column, row group, row, and then the cell.
 
         LayoutTable::ColAndColGroup colAndColGroup = m_layoutTableSection.table()->colElement(cell.col());
         LayoutTableCol* column = colAndColGroup.col;
         LayoutTableCol* columnGroup = colAndColGroup.colgroup;
         TableCellPainter tableCellPainter(cell);
 
         // Column groups and columns first.
         // FIXME: Columns and column groups do not currently support opacity, and they are being painted "too late" in
         // the stack, since we have already opened a transparency layer (potentially) for the table row group.
         // Note that we deliberately ignore whether or not the cell has a layer, since these backgrounds paint "behind" the
         // cell.
         if (columnGroup && columnGroup->hasBackground())
-            tableCellPainter.paintBackgroundsBehindCell(paintInfo, cellPoint, columnGroup, DisplayItem::TableCellBackgroundFromColumnGroup);
+            tableCellPainter.paintBackgroundsBehindCell(paintInfoForCells, cellPoint, columnGroup, DisplayItem::TableCellBackgroundFromColumnGroup);
         if (column && column->hasBackground())
-            tableCellPainter.paintBackgroundsBehindCell(paintInfo, cellPoint, column, DisplayItem::TableCellBackgroundFromColumn);
+            tableCellPainter.paintBackgroundsBehindCell(paintInfoForCells, cellPoint, column, DisplayItem::TableCellBackgroundFromColumn);
 
         // Paint the row group next.
         if (m_layoutTableSection.hasBackground())
-            tableCellPainter.paintBackgroundsBehindCell(paintInfo, cellPoint, &m_layoutTableSection, DisplayItem::TableCellBackgroundFromSection);
+            tableCellPainter.paintBackgroundsBehindCell(paintInfoForCells, cellPoint, &m_layoutTableSection, DisplayItem::TableCellBackgroundFromSection);
+    }
 
+    if (shouldPaintDescendantBlockBackgrounds(originalPaintPhase)) {
         // Paint the row next, but only if it doesn't have a layer. If a row has a layer, it will be responsible for
         // painting the row background for the cell.
         if (row->hasBackground() && !row->hasSelfPaintingLayer())
-            tableCellPainter.paintBackgroundsBehindCell(paintInfo, cellPoint, row, DisplayItem::TableCellBackgroundFromRow);
+            TableCellPainter(cell).paintBackgroundsBehindCell(paintInfoForCells, cellPoint, row, DisplayItem::TableCellBackgroundFromRow);
     }
-    if ((!cell.hasSelfPaintingLayer() && !row->hasSelfPaintingLayer()))
-        cell.paint(paintInfo, cellPoint);
+
+    if (originalPaintPhase != PaintPhaseSelfBlockBackgroundOnly && !cell.hasSelfPaintingLayer() && !row->hasSelfPaintingLayer())
+        cell.paint(paintInfoForCells, cellPoint);
 }
 
 } // namespace blink