Improvement handling of background and outline 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)
+        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);
         paintObject(paintInfo, adjustedPaintOffset);
     }
 
-    if ((paintInfo.phase == PaintPhaseOutline || paintInfo.phase == PaintPhaseSelfOutline) && m_layoutTableSection.style()->visibility() == VISIBLE)
+    if (shouldPaintSelfOutline(paintInfo.phase))
         ObjectPainter(m_layoutTableSection).paintOutline(paintInfo, adjustedPaintOffset);
 }
 
 static inline bool compareCellPositions(LayoutTableCell* elem1, LayoutTableCell* elem2)
 {
     return elem1->rowIndex() < elem2->rowIndex();
 }
 
 // This comparison is used only when we have overflowing cells as we have an unsorted array to sort. We thus need
 // to sort both on rows and columns to properly issue paint invalidations.
@@ skipping 46 matching lines @@
     localPaintInvalidationRect.moveBy(-paintOffset);
 
     LayoutRect tableAlignedRect = m_layoutTableSection.logicalRectForWritingModeAndDirection(localPaintInvalidationRect);
 
     CellSpan dirtiedRows = m_layoutTableSection.dirtiedRows(tableAlignedRect);
     CellSpan dirtiedColumns = m_layoutTableSection.dirtiedColumns(tableAlignedRect);
 
     if (dirtiedColumns.start() >= dirtiedColumns.end())
         return;
 
+    PaintInfo paintInfoForCells = paintInfo.forDescendants();
     const HashSet<LayoutTableCell*>& overflowingCells = m_layoutTableSection.overflowingCells();
     if (!m_layoutTableSection.hasMultipleCellLevels() && !overflowingCells.size()) {
         // Draw the dirty cells in the order that they appear.
         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, paintInfo, paintOffset);
+                paintCell(*cell, 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
 
         // To make sure we properly paint invalidate the section, we paint invalidated all the overflowing cells that we collected.
         Vector<LayoutTableCell*> cells;
         copyToVector(overflowingCells, cells);
 
         HashSet<LayoutTableCell*> spanningCells;
 
         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);
                 if (!current.hasCells())
                     continue;
                 for (unsigned i = 0; i < current.cells.size(); ++i) {
                     if (overflowingCells.contains(current.cells[i]))
                         continue;
 
                     if (current.cells[i]->rowSpan() > 1 || current.cells[i]->colSpan() > 1) {
                         if (!spanningCells.add(current.cells[i]).isNewEntry)
                             continue;
                     }
 
                     cells.append(current.cells[i]);
                 }
             }
         }
 
         // 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], paintInfo, paintOffset);
+            paintCell(*cells[i], paintInfoForCells, paintOffset);
     }
 }
 
 void TableSectionPainter::paintCell(const LayoutTableCell& cell, const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     LayoutPoint cellPoint = m_layoutTableSection.flipForWritingModeForChild(&cell, paintOffset);
     PaintPhase paintPhase = paintInfo.phase;
     const LayoutTableRow* row = toLayoutTableRow(cell.parent());
 
-    if ((paintPhase == PaintPhaseSelfBlockBackground || paintPhase == PaintPhaseBlockBackground)
+    if (shouldPaintSelfBlockBackground(paintPhase)
         && BlockPainter(cell).intersectsPaintRect(paintInfo, paintOffset)) {
         // 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.
@@ skipping 13 matching lines @@
         // 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);
     }
     if ((!cell.hasSelfPaintingLayer() && !row->hasSelfPaintingLayer()))
         cell.paint(paintInfo, cellPoint);
 }
 
 } // namespace blink