third_party/WebKit/Source/core/layout/ImageQualityController.cpp

   1 /*
   2  * Copyright (C) 2013 Google Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include "config.h"
  32 #include "core/layout/ImageQualityController.h"
  33
  34 #include "core/frame/FrameView.h"
  35 #include "core/frame/LocalFrame.h"
  36 #include "platform/graphics/GraphicsContext.h"
  37
  38 namespace blink {
  39
  40 static const double cLowQualityTimeThreshold = 0.500; // 500 ms
  41
  42 static ImageQualityController* gImageQualityController = nullptr;
  43
  44 ImageQualityController* ImageQualityController::imageQualityController()
  45 {
  46     if (!gImageQualityController)
  47         gImageQualityController = new ImageQualityController;
  48
  49     return gImageQualityController;
  50 }
  51
  52 void ImageQualityController::remove(LayoutObject* layoutObject)
  53 {
  54     if (gImageQualityController) {
  55         gImageQualityController->objectDestroyed(layoutObject);
  56         if (gImageQualityController->isEmpty()) {
  57             delete gImageQualityController;
  58             gImageQualityController = nullptr;
  59         }
  60     }
  61 }
  62
  63 bool ImageQualityController::has(LayoutObject* layoutObject)
  64 {
  65     return gImageQualityController && gImageQualityController->m_objectLayerSizeMap.contains(layoutObject);
  66 }
  67
  68 InterpolationQuality ImageQualityController::chooseInterpolationQuality(GraphicsContext* context, LayoutObject* object, Image* image, const void* layer, const LayoutSize& layoutSize)
  69 {
  70     if (object->style()->imageRendering() == ImageRenderingPixelated)
  71         return InterpolationNone;
  72
  73     if (InterpolationDefault == InterpolationLow)
  74         return InterpolationLow;
  75
  76     if (shouldPaintAtLowQuality(context, object, image, layer, layoutSize))
  77         return InterpolationLow;
  78
  79     // For images that are potentially animated we paint them at medium quality.
  80     if (image && image->maybeAnimated())
  81         return InterpolationMedium;
  82
  83     return InterpolationDefault;
  84 }
  85
  86 ImageQualityController::~ImageQualityController()
  87 {
  88     // This will catch users of ImageQualityController that forget to call cleanUp.
  89     ASSERT(!gImageQualityController || gImageQualityController->isEmpty());
  90 }
  91
  92 ImageQualityController::ImageQualityController()
  93     : m_timer(adoptPtr(new Timer<ImageQualityController>(this, &ImageQualityController::highQualityRepaintTimerFired)))
  94     , m_animatedResizeIsActive(false)
  95     , m_liveResizeOptimizationIsActive(false)
  96 {
  97 }
  98
  99 void ImageQualityController::setTimer(Timer<ImageQualityController>* newTimer)
 100 {
 101     m_timer = adoptPtr(newTimer);
 102 }
 103
 104 void ImageQualityController::removeLayer(LayoutObject* object, LayerSizeMap* innerMap, const void* layer)
 105 {
 106     if (innerMap) {
 107         innerMap->remove(layer);
 108         if (innerMap->isEmpty())
 109             objectDestroyed(object);
 110     }
 111 }
 112
 113 void ImageQualityController::set(LayoutObject* object, LayerSizeMap* innerMap, const void* layer, const LayoutSize& size)
 114 {
 115     if (innerMap) {
 116         innerMap->set(layer, size);
 117     } else {
 118         LayerSizeMap newInnerMap;
 119         newInnerMap.set(layer, size);
 120         m_objectLayerSizeMap.set(object, newInnerMap);
 121     }
 122 }
 123
 124 void ImageQualityController::objectDestroyed(LayoutObject* object)
 125 {
 126     m_objectLayerSizeMap.remove(object);
 127     if (m_objectLayerSizeMap.isEmpty()) {
 128         m_animatedResizeIsActive = false;
 129         m_timer->stop();
 130     }
 131 }
 132
 133 void ImageQualityController::highQualityRepaintTimerFired(Timer<ImageQualityController>*)
 134 {
 135     if (!m_animatedResizeIsActive && !m_liveResizeOptimizationIsActive)
 136         return;
 137     m_animatedResizeIsActive = false;
 138
 139     for (auto* layoutObject : m_objectLayerSizeMap.keys()) {
 140         if (LocalFrame* frame = layoutObject->document().frame()) {
 141             // If this layoutObject's containing FrameView is in live resize, punt the timer and hold back for now.
 142             if (frame->view() && frame->view()->inLiveResize()) {
 143                 restartTimer();
 144                 return;
 145             }
 146         }
 147         layoutObject->setShouldDoFullPaintInvalidation();
 148     }
 149
 150     m_liveResizeOptimizationIsActive = false;
 151 }
 152
 153 void ImageQualityController::restartTimer()
 154 {
 155     m_timer->startOneShot(cLowQualityTimeThreshold, FROM_HERE);
 156 }
 157
 158 bool ImageQualityController::shouldPaintAtLowQuality(GraphicsContext* context, LayoutObject* object, Image* image, const void *layer, const LayoutSize& layoutSize)
 159 {
 160     // If the image is not a bitmap image, then none of this is relevant and we just paint at high
 161     // quality.
 162     if (!image || !image->isBitmapImage())
 163         return false;
 164
 165     if (!layer)
 166         return false;
 167
 168     if (object->style()->imageRendering() == ImageRenderingOptimizeContrast)
 169         return true;
 170
 171     // Look ourselves up in the hashtables.
 172     ObjectLayerSizeMap::iterator i = m_objectLayerSizeMap.find(object);
 173     LayerSizeMap* innerMap = i != m_objectLayerSizeMap.end() ? &i->value : 0;
 174     LayoutSize oldSize;
 175     bool isFirstResize = true;
 176     if (innerMap) {
 177         LayerSizeMap::iterator j = innerMap->find(layer);
 178         if (j != innerMap->end()) {
 179             isFirstResize = false;
 180             oldSize = j->value;
 181         }
 182     }
 183
 184     // If the containing FrameView is being resized, paint at low quality until resizing is finished.
 185     if (LocalFrame* frame = object->document().frame()) {
 186         bool frameViewIsCurrentlyInLiveResize = frame->view() && frame->view()->inLiveResize();
 187         if (frameViewIsCurrentlyInLiveResize) {
 188             set(object, innerMap, layer, layoutSize);
 189             restartTimer();
 190             m_liveResizeOptimizationIsActive = true;
 191             return true;
 192         }
 193         if (m_liveResizeOptimizationIsActive) {
 194             // Live resize has ended, paint in HQ and remove this object from the list.
 195             removeLayer(object, innerMap, layer);
 196             return false;
 197         }
 198     }
 199
 200     if (layoutSize == image->size()) {
 201         // There is no scale in effect. If we had a scale in effect before, we can just remove this object from the list.
 202         removeLayer(object, innerMap, layer);
 203         return false;
 204     }
 205
 206     // If an animated resize is active, paint in low quality and kick the timer ahead.
 207     if (m_animatedResizeIsActive) {
 208         set(object, innerMap, layer, layoutSize);
 209         if (oldSize != layoutSize)
 210             restartTimer();
 211         return true;
 212     }
 213     // If this is the first time resizing this image, or its size is the
 214     // same as the last resize, draw at high res, but record the paint
 215     // size and set the timer.
 216     if (isFirstResize || oldSize == layoutSize) {
 217         restartTimer();
 218         set(object, innerMap, layer, layoutSize);
 219         return false;
 220     }
 221     // If the timer is no longer active, draw at high quality and don't
 222     // set the timer.
 223     if (!m_timer->isActive()) {
 224         removeLayer(object, innerMap, layer);
 225         return false;
 226     }
 227
 228     // This object has been resized to two different sizes while the timer
 229     // is active, so draw at low quality, set the flag for animated resizes and
 230     // the object to the list for high quality redraw.
 231     set(object, innerMap, layer, layoutSize);
 232     m_animatedResizeIsActive = true;
 233     restartTimer();
 234     return true;
 235 }
 236
 237 } // namespace blink