Source/WebCore/css/CSSCrossfadeValue.cpp

   1 /*
   2  * Copyright (C) 2011 Apple 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
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "CSSCrossfadeValue.h"
  28
  29 #include "CSSImageValue.h"
  30 #include "CachedImage.h"
  31 #include "CachedResourceLoader.h"
  32 #include "CrossfadeGeneratedImage.h"
  33 #include "ImageBuffer.h"
  34 #include "RenderObject.h"
  35 #include "StyleCachedImage.h"
  36 #include "StyleGeneratedImage.h"
  37
  38 namespace WebCore {
  39
  40 static bool subimageIsPending(CSSValue* value)
  41 {
  42     if (value->isImageValue())
  43         return static_cast<CSSImageValue*>(value)->cachedOrPendingImage()->isPendingImage();
  44
  45     if (value->isImageGeneratorValue())
  46         return static_cast<CSSImageGeneratorValue*>(value)->isPending();
  47
  48     ASSERT_NOT_REACHED();
  49
  50     return false;
  51 }
  52
  53 static CachedImage* cachedImageForCSSValue(CSSValue* value, CachedResourceLoader* cachedResourceLoader)
  54 {
  55     if (!value)
  56         return 0;
  57
  58     if (value->isImageValue()) {
  59         StyleCachedImage* styleCachedImage = static_cast<CSSImageValue*>(value)->cachedImage(cachedResourceLoader);
  60         if (!styleCachedImage)
  61             return 0;
  62
  63         return styleCachedImage->cachedImage();
  64     }
  65
  66     if (value->isImageGeneratorValue()) {
  67         static_cast<CSSImageGeneratorValue*>(value)->loadSubimages(cachedResourceLoader);
  68         // FIXME: Handle CSSImageGeneratorValue (and thus cross-fades with gradients and canvas).
  69         return 0;
  70     }
  71
  72     ASSERT_NOT_REACHED();
  73
  74     return 0;
  75 }
  76
  77 CSSCrossfadeValue::~CSSCrossfadeValue()
  78 {
  79     if (m_cachedFromImage)
  80         m_cachedFromImage->removeClient(&m_crossfadeSubimageObserver);
  81     if (m_cachedToImage)
  82         m_cachedToImage->removeClient(&m_crossfadeSubimageObserver);
  83 }
  84
  85 String CSSCrossfadeValue::customCssText() const
  86 {
  87     String result = "-webkit-cross-fade(";
  88     result += m_fromValue->cssText() + ", ";
  89     result += m_toValue->cssText() + ", ";
  90     result += m_percentageValue->cssText();
  91     result += ")";
  92     return result;
  93 }
  94
  95 IntSize CSSCrossfadeValue::fixedSize(const RenderObject* renderer)
  96 {
  97     float percentage = m_percentageValue->getFloatValue();
  98     float inversePercentage = 1 - percentage;
  99
 100     CachedResourceLoader* cachedResourceLoader = renderer->document()->cachedResourceLoader();
 101     CachedImage* cachedFromImage = cachedImageForCSSValue(m_fromValue.get(), cachedResourceLoader);
 102     CachedImage* cachedToImage = cachedImageForCSSValue(m_toValue.get(), cachedResourceLoader);
 103
 104     if (!cachedFromImage || !cachedToImage)
 105         return IntSize();
 106
 107     IntSize fromImageSize = cachedFromImage->imageForRenderer(renderer)->size();
 108     IntSize toImageSize = cachedToImage->imageForRenderer(renderer)->size();
 109
 110     // Rounding issues can cause transitions between images of equal size to return
 111     // a different fixed size; avoid performing the interpolation if the images are the same size.
 112     if (fromImageSize == toImageSize)
 113         return fromImageSize;
 114
 115     return IntSize(fromImageSize.width() * inversePercentage + toImageSize.width() * percentage,
 116         fromImageSize.height() * inversePercentage + toImageSize.height() * percentage);
 117 }
 118
 119 bool CSSCrossfadeValue::isPending() const
 120 {
 121     return subimageIsPending(m_fromValue.get()) || subimageIsPending(m_toValue.get());
 122 }
 123
 124 void CSSCrossfadeValue::loadSubimages(CachedResourceLoader* cachedResourceLoader)
 125 {
 126     m_cachedFromImage = cachedImageForCSSValue(m_fromValue.get(), cachedResourceLoader);
 127     m_cachedToImage = cachedImageForCSSValue(m_toValue.get(), cachedResourceLoader);
 128
 129     if (m_cachedFromImage)
 130         m_cachedFromImage->addClient(&m_crossfadeSubimageObserver);
 131     if (m_cachedToImage)
 132         m_cachedToImage->addClient(&m_crossfadeSubimageObserver);
 133
 134     m_crossfadeSubimageObserver.setReady(true);
 135 }
 136
 137 PassRefPtr<Image> CSSCrossfadeValue::image(RenderObject* renderer, const IntSize& size)
 138 {
 139     if (size.isEmpty())
 140         return 0;
 141
 142     CachedResourceLoader* cachedResourceLoader = renderer->document()->cachedResourceLoader();
 143     CachedImage* cachedFromImage = cachedImageForCSSValue(m_fromValue.get(), cachedResourceLoader);
 144     CachedImage* cachedToImage = cachedImageForCSSValue(m_toValue.get(), cachedResourceLoader);
 145
 146     if (!cachedFromImage || !cachedToImage)
 147         return Image::nullImage();
 148
 149     Image* fromImage = cachedFromImage->imageForRenderer(renderer);
 150     Image* toImage = cachedToImage->imageForRenderer(renderer);
 151
 152     if (!fromImage || !toImage)
 153         return Image::nullImage();
 154
 155     m_generatedImage = CrossfadeGeneratedImage::create(fromImage, toImage, m_percentageValue->getFloatValue(), fixedSize(renderer), size);
 156
 157     return m_generatedImage.release();
 158 }
 159
 160 void CSSCrossfadeValue::crossfadeChanged(const IntRect&)
 161 {
 162     RenderObjectSizeCountMap::const_iterator end = clients().end();
 163     for (RenderObjectSizeCountMap::const_iterator curr = clients().begin(); curr != end; ++curr) {
 164         RenderObject* client = const_cast<RenderObject*>(curr->first);
 165         client->imageChanged(static_cast<WrappedImagePtr>(this));
 166     }
 167 }
 168
 169 void CSSCrossfadeValue::CrossfadeSubimageObserverProxy::imageChanged(CachedImage*, const IntRect* rect)
 170 {
 171     if (m_ready)
 172         m_ownerValue->crossfadeChanged(*rect);
 173 }
 174
 175 } // namespace WebCore