third_party/WebKit/Source/core/layout/PaintContainmentTest.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/layout/LayoutBlock.h"
#include "core/layout/LayoutInline.h"
#include "core/layout/LayoutTestHelper.h"
#include "core/paint/PaintLayer.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace blink {

class PaintContainmentTest : public RenderingTest {
 private:
  void SetUp() override {
    RenderingTest::SetUp();
    enableCompositing();
  }
};

static void checkIsClippingStackingContextAndContainer(
    LayoutBoxModelObject& obj) {
  EXPECT_TRUE(obj.canContainFixedPositionObjects());
  EXPECT_TRUE(obj.hasClipRelatedProperty());
  EXPECT_TRUE(obj.style()->containsPaint());

  // TODO(leviw): Ideally, we wouldn't require a paint layer to handle the
  // clipping and stacking performed by paint containment.
  ASSERT(obj.layer());
  PaintLayer* layer = obj.layer();
  EXPECT_TRUE(layer->stackingNode() &&
              layer->stackingNode()->isStackingContext());
}

TEST_F(PaintContainmentTest, BlockPaintContainment) {
  setBodyInnerHTML("<div id='div' style='contain: paint'></div>");
  Element* div = document().getElementById(AtomicString("div"));
  ASSERT(div);
  LayoutObject* obj = div->layoutObject();
  ASSERT(obj && obj->isLayoutBlock());
  LayoutBlock& block = toLayoutBlock(*obj);
  EXPECT_TRUE(block.createsNewFormattingContext());
  EXPECT_FALSE(block.canBeScrolledAndHasScrollableArea());
  checkIsClippingStackingContextAndContainer(block);
}

TEST_F(PaintContainmentTest, InlinePaintContainment) {
  setBodyInnerHTML(
      "<div><span id='test' style='contain: paint'>Foo</span></div>");
  Element* span = document().getElementById(AtomicString("test"));
  ASSERT(span);
  // The inline should have been coerced into a block in StyleAdjuster.
  LayoutObject* obj = span->layoutObject();
  ASSERT(obj && obj->isLayoutBlock());
  LayoutBlock& layoutBlock = toLayoutBlock(*obj);
  checkIsClippingStackingContextAndContainer(layoutBlock);
}

TEST_F(PaintContainmentTest, SvgWithContainmentShouldNotCrash) {
  // SVG doesn't currently support PaintLayers and should not crash with
  // layer-related properties.
  setBodyInnerHTML("<svg><text y='20' style='contain: paint'>Foo</text></svg>");
  setBodyInnerHTML(
      "<svg><foreignObject style='contain: paint'>Foo</foreignObject></svg>");
  setBodyInnerHTML(
      "<svg><foreignObject><span style='contain: "
      "paint'>Foo</span></foreignObject></svg>");
}

}  // namespace blink