1 /* 2 * Copyright (C) 2004, 2006, 2009, 2010 Apple Inc. All rights reserved. 3 * Copyright (C) 2007 Alp Toker <alp (at) atoker.com> 4 * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY 16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 22 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 23 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #ifndef HTMLCanvasElement_h 29 #define HTMLCanvasElement_h 30 31 #include "core/dom/Document.h" 32 #include "core/html/HTMLElement.h" 33 #include "core/html/canvas/CanvasImageSource.h" 34 #include "platform/geometry/FloatRect.h" 35 #include "platform/geometry/IntSize.h" 36 #include "platform/graphics/Canvas2DLayerBridge.h" 37 #include "platform/graphics/GraphicsTypes.h" 38 #include "platform/graphics/ImageBufferClient.h" 39 #include "platform/heap/Handle.h" 40 #include "public/platform/WebThread.h" 41 #include "wtf/Forward.h" 42 43 #define CanvasDefaultInterpolationQuality InterpolationLow 44 45 namespace blink { 46 47 class AffineTransform; 48 class CanvasContextAttributes; 49 class CanvasRenderingContext; 50 class GraphicsContext; 51 class GraphicsContextStateSaver; 52 class HTMLCanvasElement; 53 class Image; 54 class ImageData; 55 class ImageBuffer; 56 class ImageBufferSurface; 57 class IntSize; 58 59 class CanvasObserver : public WillBeGarbageCollectedMixin { 60 DECLARE_EMPTY_VIRTUAL_DESTRUCTOR_WILL_BE_REMOVED(CanvasObserver); 61 public: 62 virtual void canvasChanged(HTMLCanvasElement*, const FloatRect& changedRect) = 0; 63 virtual void canvasResized(HTMLCanvasElement*) = 0; 64 #if !ENABLE(OILPAN) 65 virtual void canvasDestroyed(HTMLCanvasElement*) = 0; 66 #endif 67 68 virtual void trace(Visitor*) { } 69 }; 70 71 class HTMLCanvasElement FINAL : public HTMLElement, public DocumentVisibilityObserver, public CanvasImageSource, public ImageBufferClient, public blink::WebThread::TaskObserver { 72 DEFINE_WRAPPERTYPEINFO(); 73 WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(HTMLCanvasElement); 74 public: 75 DECLARE_NODE_FACTORY(HTMLCanvasElement); 76 virtual ~HTMLCanvasElement(); 77 78 void addObserver(CanvasObserver*); 79 void removeObserver(CanvasObserver*); 80 81 // Attributes and functions exposed to script 82 int width() const { return size().width(); } 83 int height() const { return size().height(); } 84 85 const IntSize& size() const { return m_size; } 86 87 void setWidth(int); 88 void setHeight(int); 89 void setAccelerationDisabled(bool accelerationDisabled) { m_accelerationDisabled = accelerationDisabled; } 90 bool accelerationDisabled() const { return m_accelerationDisabled; } 91 92 void setSize(const IntSize& newSize) 93 { 94 if (newSize == size()) 95 return; 96 m_ignoreReset = true; 97 setWidth(newSize.width()); 98 setHeight(newSize.height()); 99 m_ignoreReset = false; 100 reset(); 101 } 102 103 CanvasRenderingContext* getContext(const String&, CanvasContextAttributes* attributes = 0); 104 105 static String toEncodingMimeType(const String& mimeType); 106 String toDataURL(const String& mimeType, const double* quality, ExceptionState&) const; 107 String toDataURL(const String& mimeType, ExceptionState& exceptionState) const { return toDataURL(mimeType, 0, exceptionState); } 108 109 // Used for rendering 110 void didDraw(const FloatRect&); 111 void notifyObserversCanvasChanged(const FloatRect&); 112 113 void paint(GraphicsContext*, const LayoutRect&); 114 115 GraphicsContext* drawingContext() const; 116 GraphicsContext* existingDrawingContext() const; 117 118 CanvasRenderingContext* renderingContext() const { return m_context.get(); } 119 120 void ensureUnacceleratedImageBuffer(); 121 ImageBuffer* buffer() const; 122 Image* copiedImage() const; 123 void clearCopiedImage(); 124 PassRefPtrWillBeRawPtr<ImageData> getImageData() const; 125 void makePresentationCopy(); 126 void clearPresentationCopy(); 127 128 SecurityOrigin* securityOrigin() const; 129 bool originClean() const { return m_originClean; } 130 void setOriginTainted() { m_originClean = false; } 131 132 AffineTransform baseTransform() const; 133 134 bool is3D() const; 135 136 bool hasImageBuffer() const { return m_imageBuffer; } 137 bool hasValidImageBuffer() const; 138 void discardImageBuffer(); 139 140 bool shouldAccelerate(const IntSize&) const; 141 142 virtual const AtomicString imageSourceURL() const OVERRIDE; 143 144 virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE; 145 146 // DocumentVisibilityObserver implementation 147 virtual void didChangeVisibilityState(PageVisibilityState) OVERRIDE; 148 149 // CanvasImageSource implementation 150 virtual PassRefPtr<Image> getSourceImageForCanvas(SourceImageMode, SourceImageStatus*) const OVERRIDE; 151 virtual bool wouldTaintOrigin(SecurityOrigin*) const OVERRIDE; 152 virtual FloatSize sourceSize() const OVERRIDE; 153 154 // ImageBufferClient implementation 155 virtual void notifySurfaceInvalid() OVERRIDE; 156 virtual bool isDirty() OVERRIDE { return !m_dirtyRect.isEmpty(); } 157 virtual void didFinalizeFrame() OVERRIDE; 158 159 // Implementation of WebThread::TaskObserver methods 160 virtual void willProcessTask() OVERRIDE; 161 virtual void didProcessTask() OVERRIDE; 162 163 virtual void trace(Visitor*) OVERRIDE; 164 165 protected: 166 virtual void didMoveToNewDocument(Document& oldDocument) OVERRIDE; 167 168 private: 169 explicit HTMLCanvasElement(Document&); 170 171 virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE; 172 virtual RenderObject* createRenderer(RenderStyle*) OVERRIDE; 173 virtual bool areAuthorShadowsAllowed() const OVERRIDE { return false; } 174 175 void reset(); 176 177 PassOwnPtr<ImageBufferSurface> createImageBufferSurface(const IntSize& deviceSize, int* msaaSampleCount); 178 void createImageBuffer(); 179 void createImageBufferInternal(); 180 void clearImageBuffer(); 181 182 void resetDirtyRect(); 183 184 void setSurfaceSize(const IntSize&); 185 186 bool paintsIntoCanvasBuffer() const; 187 188 void updateExternallyAllocatedMemory() const; 189 190 String toDataURLInternal(const String& mimeType, const double* quality, bool isSaving = false) const; 191 192 WillBeHeapHashSet<RawPtrWillBeWeakMember<CanvasObserver> > m_observers; 193 194 IntSize m_size; 195 196 OwnPtrWillBeMember<CanvasRenderingContext> m_context; 197 198 bool m_ignoreReset; 199 bool m_accelerationDisabled; 200 FloatRect m_dirtyRect; 201 202 mutable intptr_t m_externallyAllocatedMemory; 203 204 bool m_originClean; 205 206 // It prevents HTMLCanvasElement::buffer() from continuously re-attempting to allocate an imageBuffer 207 // after the first attempt failed. 208 mutable bool m_didFailToCreateImageBuffer; 209 mutable bool m_didClearImageBuffer; 210 OwnPtr<ImageBuffer> m_imageBuffer; 211 mutable OwnPtr<GraphicsContextStateSaver> m_contextStateSaver; 212 213 mutable RefPtr<Image> m_presentedImage; 214 mutable RefPtr<Image> m_copiedImage; // FIXME: This is temporary for platforms that have to copy the image buffer to render (and for CSSCanvasValue). 215 }; 216 217 } // namespace blink 218 219 #endif // HTMLCanvasElement_h 220
