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(RenderObject& renderer)
  17     : m_clipped(false)
  18     , m_cachedOffsetsEnabled(true)
  19     , m_forceCheckForPaintInvalidation(false)
  20     , m_paintInvalidationContainer(*renderer.containerForPaintInvalidation())
  21     , m_renderer(renderer)
  22 {
  23     bool establishesPaintInvalidationContainer = &m_renderer == &m_paintInvalidationContainer;
  24     if (!establishesPaintInvalidationContainer) {
  25         if (!renderer.supportsPaintInvalidationStateCachedOffsets()) {
  26             m_cachedOffsetsEnabled = false;
  27             return;
  28         }
  29         bool invalidationContainerSkipped;
  30         RenderObject* container = renderer.container(&m_paintInvalidationContainer, &invalidationContainerSkipped);
  31         if (container && !invalidationContainerSkipped) {
  32             FloatPoint point = container->localToContainerPoint(FloatPoint(), &m_paintInvalidationContainer);
  33             if (container->isTableRow())
  34                 point = FloatPoint(point.x() - toRenderBox(container)->x().toFloat(), point.y() - toRenderBox(container)->y().toFloat());
  35             m_paintOffset = LayoutSize(point.x(), point.y());
  36
  37             applyClipIfNeeded(*container);
  38         }
  39     } else {
  40         applyClipIfNeeded(m_renderer);
  41     }
  42 }
  43
  44 PaintInvalidationState::PaintInvalidationState(const PaintInvalidationState& next, RenderLayerModelObject& renderer, const RenderLayerModelObject& paintInvalidationContainer)
  45     : m_clipped(false)
  46     , m_cachedOffsetsEnabled(true)
  47     , m_forceCheckForPaintInvalidation(next.m_forceCheckForPaintInvalidation)
  48     , m_paintInvalidationContainer(paintInvalidationContainer)
  49     , m_renderer(renderer)
  50 {
  51     // FIXME: SVG could probably benefit from a stack-based optimization like html does. crbug.com/391054
  52     bool establishesPaintInvalidationContainer = &m_renderer == &m_paintInvalidationContainer;
  53     bool fixed = m_renderer.isOutOfFlowPositioned() && m_renderer.style()->position() == FixedPosition;
  54
  55     if (establishesPaintInvalidationContainer) {
  56         // When we hit a new paint invalidation container, we don't need to
  57         // continue forcing a check for paint invalidation because movement
  58         // from our parents will just move the whole invalidation container.
  59         m_forceCheckForPaintInvalidation = false;
  60     } else {
  61         if (!renderer.supportsPaintInvalidationStateCachedOffsets() || !next.m_cachedOffsetsEnabled) {
  62             m_cachedOffsetsEnabled = false;
  63         } else {
  64             LayoutSize offset = m_renderer.isBox() && !m_renderer.isTableRow() ? toRenderBox(renderer).locationOffset() : LayoutSize();
  65             if (fixed) {
  66                 // FIXME: This doesn't work correctly with transforms.
  67                 FloatPoint fixedOffset = m_renderer.view()->localToAbsolute(FloatPoint(), IsFixed);
  68                 m_paintOffset = LayoutSize(fixedOffset.x(), fixedOffset.y()) + offset;
  69             } else {
  70                 m_paintOffset = next.m_paintOffset + offset;
  71             }
  72
  73             if (m_renderer.isOutOfFlowPositioned() && !fixed) {
  74                 if (RenderObject* container = m_renderer.container()) {
  75                     if (container->style()->hasInFlowPosition() && container->isRenderInline())
  76                         m_paintOffset += toRenderInline(container)->offsetForInFlowPositionedInline(toRenderBox(renderer));
  77                 }
  78             }
  79
  80             if (m_renderer.style()->hasInFlowPosition() && renderer.hasLayer())
  81                 m_paintOffset += renderer.layer()->offsetForInFlowPosition();
  82         }
  83
  84         m_clipped = !fixed && next.m_clipped;
  85         if (m_clipped)
  86             m_clipRect = next.m_clipRect;
  87     }
  88
  89     applyClipIfNeeded(renderer);
  90
  91     // FIXME: <http://bugs.webkit.org/show_bug.cgi?id=13443> Apply control clip if present.
  92 }
  93
  94 void PaintInvalidationState::applyClipIfNeeded(const RenderObject& renderer)
  95 {
  96     if (!renderer.hasOverflowClip())
  97         return;
  98
  99     const RenderBox& box = toRenderBox(renderer);
 100
 101     // Do not clip scroll layer contents because the compositor expects the whole layer
 102     // to be always invalidated in-time.
 103     if (box.usesCompositedScrolling()) {
 104         ASSERT(!m_clipped); // The box should establish paint invalidation container, so no m_clipped inherited.
 105     } else {
 106         LayoutRect clipRect(toPoint(m_paintOffset), box.layer()->size());
 107         if (m_clipped) {
 108             m_clipRect.intersect(clipRect);
 109         } else {
 110             m_clipRect = clipRect;
 111             m_clipped = true;
 112         }
 113     }
 114
 115     m_paintOffset -= box.scrolledContentOffset();
 116 }
 117
 118 } // namespace blink