Paint collapsed borders of a table as one display item

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

+// Copyright 2015 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/PaintControllerPaintTest.h"
+#include "platform/graphics/paint/DrawingDisplayItem.h"
+
+namespace blink {
+
+using TablePainterTest = PaintControllerPaintTest;
+
+TEST_F(TablePainterTest, CollapsedBorderInterestRectChange) {
+  setBodyInnerHTML(
+      "<style>"
+      "  table { border-collapse: collapse; position: absolute; }"
+      "  td { width: 100px; height: 100px; border: 2px solid blue; }"
+      "</style>"
+      "<table id='table'>"
+      "  <tr><td></td><td></td><td></td><td></td></tr>"
+      "  <tr><td></td><td></td><td></td><td></td></tr>"
+      "  <tr><td></td><td></td><td></td><td></td></tr>"
+      "  <tr><td></td><td></td><td></td><td></td></tr>"
+      "</table>");
+
+  PaintLayer& htmlLayer =
+      *toLayoutBoxModelObject(document().documentElement()->layoutObject())
+           ->layer();
+  LayoutObject& table = *getLayoutObjectByElementId("table");
+
+  rootPaintController().invalidateAll();
+  document().view()->updateAllLifecyclePhasesExceptPaint();
+  IntRect interestRect(300, 300, 300, 300);
+  paint(&interestRect);
+
+  EXPECT_DISPLAY_LIST(
+      rootPaintController().getDisplayItemList(), 4,
+      TestDisplayItem(layoutView(), documentBackgroundType),
+      TestDisplayItem(htmlLayer, DisplayItem::kSubsequence),
+      TestDisplayItem(table, DisplayItem::kTableCollapsedBorders),
+      TestDisplayItem(htmlLayer, DisplayItem::kEndSubsequence));
+  // Painted collapsed borders of the central 4 cells, each 4 operations.
+  EXPECT_EQ(16, static_cast<const DrawingDisplayItem&>(
+                    rootPaintController().getDisplayItemList()[2])
+                    .picture()
+                    ->approximateOpCount());
+
+  // Should repaint collapsed borders if the previous paint didn't fully paint
+  // and interest rect changes.
+  document().view()->updateAllLifecyclePhasesExceptPaint();
+  interestRect = IntRect(0, 0, 1000, 1000);
+  EXPECT_TRUE(paintWithoutCommit(&interestRect));
+  EXPECT_EQ(1, numCachedNewItems());
+  commit();
+  EXPECT_DISPLAY_LIST(
+      rootPaintController().getDisplayItemList(), 4,
+      TestDisplayItem(layoutView(), documentBackgroundType),
+      TestDisplayItem(htmlLayer, DisplayItem::kSubsequence),
+      TestDisplayItem(table, DisplayItem::kTableCollapsedBorders),
+      TestDisplayItem(htmlLayer, DisplayItem::kEndSubsequence));
+  // Painted collapsed borders of all 16 cells, each 4 operations.
+  EXPECT_EQ(64, static_cast<const DrawingDisplayItem&>(
+                    rootPaintController().getDisplayItemList()[2])
+                    .picture()
+                    ->approximateOpCount());
+
+  // Should not repaint collapsed borders if the previous paint fully painted
+  // and interest rect changes.
+  document().view()->updateAllLifecyclePhasesExceptPaint();
+  interestRect = IntRect(0, 0, 400, 400);
+  EXPECT_TRUE(paintWithoutCommit(&interestRect));
+  EXPECT_EQ(4, numCachedNewItems());
+  commit();
+}
+
+}  // namespace blink