src/third_party/WebKit/Source/core/rendering/PaintInvalidationState.cpp

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "config.h"
   6 #include "core/rendering/PaintInvalidationState.h"
   7
   8 #include "core/rendering/RenderInline.h"
   9 #include "core/rendering/RenderLayer.h"
  10 #include "core/rendering/RenderView.h"
  11 #include "core/rendering/svg/RenderSVGModelObject.h"
  12 #include "platform/Partitions.h"
  13
  14 namespace blink {
  15
  16 PaintInvalidationState::PaintInvalidationState(const RenderView& renderView)
  17     : m_clipped(false)
  18     , m_cachedOffsetsEnabled(true)
  19     , m_forceCheckForPaintInvalidation(false)
  20     , m_paintInvalidationContainer(*renderView.containerForPaintInvalidation())
  21 {
  22     bool establishesPaintInvalidationContainer = renderView == m_paintInvalidationContainer;
  23     if (!establishesPaintInvalidationContainer) {
  24         if (!renderView.supportsPaintInvalidationStateCachedOffsets()) {
  25             m_cachedOffsetsEnabled = false;
  26             return;
  27         }
  28         FloatPoint point = renderView.localToContainerPoint(FloatPoint(), &m_paintInvalidationContainer, TraverseDocumentBoundaries);
  29         m_paintOffset = LayoutSize(point.x(), point.y());
  30     }
  31     m_clipRect = renderView.viewRect();
  32     m_clipRect.move(m_paintOffset);
  33     m_clipped = true;
  34 }
  35
  36 PaintInvalidationState::PaintInvalidationState(const PaintInvalidationState& next, RenderLayerModelObject& renderer, const RenderLayerModelObject& paintInvalidationContainer)
  37     : m_clipped(false)
  38     , m_cachedOffsetsEnabled(true)
  39     , m_forceCheckForPaintInvalidation(next.m_forceCheckForPaintInvalidation)
  40     , m_paintInvalidationContainer(paintInvalidationContainer)
  41 {
  42     // FIXME: SVG could probably benefit from a stack-based optimization like html does. crbug.com/391054
  43     bool establishesPaintInvalidationContainer = renderer == m_paintInvalidationContainer;
  44     bool fixed = renderer.style()->position() == FixedPosition;
  45
  46     if (establishesPaintInvalidationContainer) {
  47         // When we hit a new paint invalidation container, we don't need to
  48         // continue forcing a check for paint invalidation because movement
  49         // from our parents will just move the whole invalidation container.
  50         m_forceCheckForPaintInvalidation = false;
  51     } else {
  52         if (!renderer.supportsPaintInvalidationStateCachedOffsets() || !next.m_cachedOffsetsEnabled) {
  53             m_cachedOffsetsEnabled = false;
  54         } else {
  55             if (fixed) {
  56                 FloatPoint fixedOffset = renderer.localToContainerPoint(FloatPoint(), &m_paintInvalidationContainer, TraverseDocumentBoundaries);
  57                 m_paintOffset = LayoutSize(fixedOffset.x(), fixedOffset.y());
  58             } else {
  59                 LayoutSize offset = renderer.isBox() && !renderer.isTableRow() ? toRenderBox(renderer).locationOffset() : LayoutSize();
  60                 m_paintOffset = next.m_paintOffset + offset;
  61             }
  62
  63             if (renderer.isOutOfFlowPositioned() && !fixed) {
  64                 if (RenderObject* container = renderer.container()) {
  65                     if (container->style()->hasInFlowPosition() && container->isRenderInline())
  66                         m_paintOffset += toRenderInline(container)->offsetForInFlowPositionedInline(toRenderBox(renderer));
  67                 }
  68             }
  69
  70             if (renderer.style()->hasInFlowPosition() && renderer.hasLayer())
  71                 m_paintOffset += renderer.layer()->offsetForInFlowPosition();
  72         }
  73
  74         m_clipped = !fixed && next.m_clipped;
  75         if (m_clipped)
  76             m_clipRect = next.m_clipRect;
  77     }
  78
  79     applyClipIfNeeded(renderer);
  80
  81     // FIXME: <http://bugs.webkit.org/show_bug.cgi?id=13443> Apply control clip if present.
  82 }
  83
  84 void PaintInvalidationState::applyClipIfNeeded(const RenderObject& renderer)
  85 {
  86     if (!renderer.hasOverflowClip())
  87         return;
  88
  89     const RenderBox& box = toRenderBox(renderer);
  90
  91     // Do not clip scroll layer contents because the compositor expects the whole layer
  92     // to be always invalidated in-time.
  93     if (box.usesCompositedScrolling()) {
  94         ASSERT(!m_clipped); // The box should establish paint invalidation container, so no m_clipped inherited.
  95     } else {
  96         LayoutRect clipRect(toPoint(m_paintOffset), box.layer()->size());
  97         if (m_clipped) {
  98             m_clipRect.intersect(clipRect);
  99         } else {
 100             m_clipRect = clipRect;
 101             m_clipped = true;
 102         }
 103     }
 104
 105     m_paintOffset -= box.scrolledContentOffset();
 106 }
 107
 108 } // namespace blink