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 "core/rendering/svg/RenderSVGRoot.h"
  13 #include "platform/Partitions.h"
  14
  15 namespace blink {
  16
  17 PaintInvalidationState::PaintInvalidationState(const RenderView& renderView)
  18     : m_clipped(false)
  19     , m_cachedOffsetsEnabled(true)
  20     , m_forceCheckForPaintInvalidation(false)
  21     , m_paintInvalidationContainer(*renderView.containerForPaintInvalidation())
  22 {
  23     bool establishesPaintInvalidationContainer = renderView == m_paintInvalidationContainer;
  24     if (!establishesPaintInvalidationContainer) {
  25         if (!renderView.supportsPaintInvalidationStateCachedOffsets()) {
  26             m_cachedOffsetsEnabled = false;
  27             return;
  28         }
  29         FloatPoint point = renderView.localToContainerPoint(FloatPoint(), &m_paintInvalidationContainer, TraverseDocumentBoundaries);
  30         m_paintOffset = LayoutSize(point.x(), point.y());
  31     }
  32     m_clipRect = renderView.viewRect();
  33     m_clipRect.move(m_paintOffset);
  34     m_clipped = true;
  35 }
  36
  37 PaintInvalidationState::PaintInvalidationState(const PaintInvalidationState& next, RenderLayerModelObject& renderer, const RenderLayerModelObject& paintInvalidationContainer)
  38     : m_clipped(false)
  39     , m_cachedOffsetsEnabled(true)
  40     , m_forceCheckForPaintInvalidation(next.m_forceCheckForPaintInvalidation)
  41     , m_paintInvalidationContainer(paintInvalidationContainer)
  42 {
  43     // FIXME: SVG could probably benefit from a stack-based optimization like html does. crbug.com/391054
  44     bool establishesPaintInvalidationContainer = renderer == m_paintInvalidationContainer;
  45     bool fixed = renderer.style()->position() == FixedPosition;
  46
  47     if (establishesPaintInvalidationContainer) {
  48         // When we hit a new paint invalidation container, we don't need to
  49         // continue forcing a check for paint invalidation because movement
  50         // from our parents will just move the whole invalidation container.
  51         m_forceCheckForPaintInvalidation = false;
  52     } else {
  53         if (!renderer.supportsPaintInvalidationStateCachedOffsets() || !next.m_cachedOffsetsEnabled) {
  54             m_cachedOffsetsEnabled = false;
  55         } else {
  56             if (fixed) {
  57                 FloatPoint fixedOffset = renderer.localToContainerPoint(FloatPoint(), &m_paintInvalidationContainer, TraverseDocumentBoundaries);
  58                 m_paintOffset = LayoutSize(fixedOffset.x(), fixedOffset.y());
  59             } else {
  60                 LayoutSize offset = renderer.isBox() && !renderer.isTableRow() ? toRenderBox(renderer).locationOffset() : LayoutSize();
  61                 m_paintOffset = next.m_paintOffset + offset;
  62             }
  63
  64             if (renderer.isOutOfFlowPositioned() && !fixed) {
  65                 if (RenderObject* container = renderer.container()) {
  66                     if (container->style()->hasInFlowPosition() && container->isRenderInline())
  67                         m_paintOffset += toRenderInline(container)->offsetForInFlowPositionedInline(toRenderBox(renderer));
  68                 }
  69             }
  70
  71             if (renderer.style()->hasInFlowPosition() && renderer.hasLayer())
  72                 m_paintOffset += renderer.layer()->offsetForInFlowPosition();
  73         }
  74
  75         m_clipped = !fixed && next.m_clipped;
  76         if (m_clipped)
  77             m_clipRect = next.m_clipRect;
  78     }
  79
  80     if (m_cachedOffsetsEnabled && renderer.isSVGRoot()) {
  81         const RenderSVGRoot& svgRoot = toRenderSVGRoot(renderer);
  82         m_svgTransform = adoptPtr(new AffineTransform(svgRoot.localToBorderBoxTransform()));
  83         if (svgRoot.shouldApplyViewportClip())
  84             addClipRectRelativeToPaintOffset(svgRoot.pixelSnappedSize());
  85     }
  86
  87     applyClipIfNeeded(renderer);
  88
  89     // FIXME: <http://bugs.webkit.org/show_bug.cgi?id=13443> Apply control clip if present.
  90 }
  91
  92 PaintInvalidationState::PaintInvalidationState(const PaintInvalidationState& next, const RenderSVGModelObject& renderer)
  93     : m_clipped(next.m_clipped)
  94     , m_cachedOffsetsEnabled(next.m_cachedOffsetsEnabled)
  95     , m_forceCheckForPaintInvalidation(next.m_forceCheckForPaintInvalidation)
  96     , m_clipRect(next.m_clipRect)
  97     , m_paintOffset(next.m_paintOffset)
  98     , m_paintInvalidationContainer(next.m_paintInvalidationContainer)
  99 {
 100     ASSERT(renderer != m_paintInvalidationContainer);
 101
 102     if (m_cachedOffsetsEnabled)
 103         m_svgTransform = adoptPtr(new AffineTransform(next.svgTransform() * renderer.localToParentTransform()));
 104 }
 105
 106 void PaintInvalidationState::addClipRectRelativeToPaintOffset(const LayoutSize& clipSize)
 107 {
 108     LayoutRect clipRect(toPoint(m_paintOffset), clipSize);
 109     if (m_clipped) {
 110         m_clipRect.intersect(clipRect);
 111     } else {
 112         m_clipRect = clipRect;
 113         m_clipped = true;
 114     }
 115 }
 116
 117 void PaintInvalidationState::applyClipIfNeeded(const RenderObject& renderer)
 118 {
 119     if (!renderer.hasOverflowClip())
 120         return;
 121
 122     const RenderBox& box = toRenderBox(renderer);
 123
 124     // Do not clip scroll layer contents because the compositor expects the whole layer
 125     // to be always invalidated in-time.
 126     if (box.usesCompositedScrolling())
 127         ASSERT(!m_clipped); // The box should establish paint invalidation container, so no m_clipped inherited.
 128     else
 129         addClipRectRelativeToPaintOffset(box.layer()->size());
 130
 131     m_paintOffset -= box.scrolledContentOffset();
 132 }
 133
 134 } // namespace blink