Table cell background painting

third_party/WebKit/Source/core/layout/LayoutTableSection.cpp

Index: third_party/WebKit/Source/core/layout/LayoutTableSection.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutTableSection.cpp b/third_party/WebKit/Source/core/layout/LayoutTableSection.cpp
index 89b925af6f41a1551f1d609cd14bd23c85fada16..c1b7f242e64dff22bf96ede4555ec74f425a9260 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableSection.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutTableSection.cpp
@@ -1647,4 +1647,81 @@ void LayoutTableSection::setLogicalPositionForCell(LayoutTableCell* cell, unsign
     cell->setLogicalLocation(cellLocation);
 }
 
+// Returns position ideal cell relative to section
+// Ideal cell is a cell that spans single row/column.
+// It is used to calculate position of colgroup/col/row
+// It is needed because actual cells can be arbitrary rectangles, or non-existent
+// Position is relative to section

[Xianzhu, 2016/03/09 18:40:56]

Move comments into header file.

[atotic1, 2016/03/15 16:50:48]

Done.

+LayoutRect LayoutTableSection::positionOfIdealCell(unsigned row, unsigned effectiveCol) const
+{
+    LayoutTable * table = this->table();
+
+    LayoutUnit left = LayoutUnit(table->effectiveColumnPositions()[effectiveCol]);
+    LayoutUnit top = LayoutUnit(m_rowPos[row]);
+    LayoutUnit right = LayoutUnit(table->effectiveColumnPositions()[effectiveCol+1]);
+    LayoutUnit bottom = LayoutUnit(m_rowPos[row+1]);
+    left += LayoutUnit(table->hBorderSpacing());
+
+    LayoutRect position(LayoutPoint(left, top), LayoutSize(right - left, bottom - top));

[Xianzhu, 2016/03/09 18:40:56]

Change to: LayoutRect position(left, top, right - left, bottom - top);

[atotic1, 2016/03/15 16:50:48]

Done.

[atotic1, 2016/03/15 16:50:48]

Done.

+
+    // we get mode/position from row
+    const LayoutTableRow* rowLayout = rowLayoutObjectAt(row);
+    WritingMode writingMode = rowLayout ? rowLayout->style()->getWritingMode() : TopToBottomWritingMode;

[Xianzhu, 2016/03/09 18:40:56]

Why fallback to TopToBottomWritingMode if there is no row?

[atotic1, 2016/03/15 16:50:48]

Just defensive coding because I have no guarantees when any pointer returning
routine will return null. 
I can just ASSERT(rowLayout)

+    bool isLTR = style()->isLeftToRightDirection();

[Xianzhu, 2016/03/09 18:40:56]

The code below can be simplified by reusing existing writing mode and direction
handling code. You can check
LayoutTableSection::logicalRectForWritingModeAndDirection() (which seems the
inversion of the code below) to see how and what can be reused.

BTW I guess you would be interested in fixing the FIXME in
LayoutTableSection::logicalRectForWritingModeAndDirection(). You can look at the
patch that Julien created in https://bugs.webkit.org/show_bug.cgi?id=96691 if
you are interested.

+
+    // LOG(INFO) << "ideal [" << row << ", " << col << "] " <<
+    //     position.x().toInt() << ", " << position.y().toInt() << " " <<
+    //     position.width().toInt() << " x " << position.height().toInt();
+
+    if (blink::isHorizontalWritingMode(writingMode)) {
+        if (isLTR) {
+            position.setLocation(LayoutPoint(left, top));
+            position.setSize(LayoutSize(right - left, bottom - top));
+        } else {
+            LayoutUnit width = size().width();
+            left = width - left;
+            right = width - right;
+            std::swap(left, right);
+            position.setLocation(LayoutPoint(left, top));
+            position.setSize(LayoutSize(right - left, bottom - top));
+        }
+    } else if (isFlippedLinesWritingMode(writingMode)) {
+        if (isLTR) {
+            position = position.transposedRect();
+        } else {
+            LayoutUnit height = size().height();
+            auto tmpTop = top;
+            auto tmpBottom = bottom;
+            top = height - right;
+            bottom = height -left;
+            left = tmpTop;
+            right = tmpBottom;
+            position.setLocation(LayoutPoint(left, top));
+            position.setSize(LayoutSize(right - left, bottom - top));
+        }
+    } else if (isFlippedBlocksWritingMode(writingMode)) {
+        if (isLTR) {
+            LayoutUnit width = size().width();
+            position.setLocation(LayoutPoint(width - bottom, left));
+            position.setSize(LayoutSize(bottom - top, right - left));
+        } else {
+            LayoutUnit width = size().width();
+            LayoutUnit height = size().height();
+            auto tmpLeft = left;
+            auto tmpRight = right;
+            left = width - bottom;
+            right = width - top;
+            top = height - tmpRight;
+            bottom = height - tmpLeft;
+            position.setLocation(LayoutPoint(left, top));
+            position.setSize(LayoutSize(right - left, bottom - top));
+        }
+    }
+
+    // LOG(INFO) << "after [" << row << ", " << col << "] " <<
+        // position.x().toInt() << ", " << position.y().toInt() << " " <<
+        // position.width().toInt() << " x " << position.height().toInt();

[Xianzhu, 2016/03/09 18:40:56]

Please remove temporary debug code before sending out a CL for review.

[atotic1, 2016/03/15 16:50:48]

Done. Rewrote as a much simpler version.

+    return position;
+}
+
 } // namespace blink