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/*
* Copyright (C) 2009 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef CanvasRenderingContext_h
#define CanvasRenderingContext_h
#include "core/CoreExport.h"
#include "core/html/HTMLCanvasElement.h"
#include "core/html/canvas/CanvasContextCreationAttributes.h"
#include "core/layout/HitTestCanvasResult.h"
#include "core/offscreencanvas/OffscreenCanvas.h"
#include "platform/graphics/ColorBehavior.h"
#include "third_party/skia/include/core/SkColorSpace.h"
#include "third_party/skia/include/core/SkImageInfo.h"
#include "wtf/HashSet.h"
#include "wtf/Noncopyable.h"
#include "wtf/text/StringHash.h"
class SkCanvas;
namespace blink {
class CanvasImageSource;
class HTMLCanvasElement;
class ImageData;
class ImageBitmap;
class WebLayer;
enum CanvasColorSpace {
kLegacyCanvasColorSpace,
kSRGBCanvasColorSpace,
kLinearRGBCanvasColorSpace,
};
class CORE_EXPORT CanvasRenderingContext
: public GarbageCollectedFinalized<CanvasRenderingContext>,
public ScriptWrappable {
WTF_MAKE_NONCOPYABLE(CanvasRenderingContext);
USING_PRE_FINALIZER(CanvasRenderingContext, dispose);
public:
virtual ~CanvasRenderingContext() {}
// A Canvas can either be "2D" or "webgl" but never both. If you request a 2D
// canvas and the existing context is already 2D, just return that. If the
// existing context is WebGL, then destroy it before creating a new 2D
// context. Vice versa when requesting a WebGL canvas. Requesting a context
// with any other type string will destroy any existing context.
enum ContextType {
// Do not change assigned numbers of existing items: add new features to the
// end of the list.
Context2d = 0,
ContextExperimentalWebgl = 2,
ContextWebgl = 3,
ContextWebgl2 = 4,
ContextImageBitmap = 5,
ContextTypeCount,
};
static ContextType contextTypeFromId(const String& id);
static ContextType resolveContextTypeAliases(ContextType);
HTMLCanvasElement* canvas() const { return m_canvas; }
CanvasColorSpace colorSpace() const { return m_colorSpace; };
WTF::String colorSpaceAsString() const;
sk_sp<SkColorSpace> skColorSpace() const;
SkColorType colorType() const;
ColorBehavior colorBehaviorForMediaDrawnToCanvas() const;
virtual PassRefPtr<Image> getImage(AccelerationHint,
SnapshotReason) const = 0;
virtual ImageData* toImageData(SnapshotReason reason) { return nullptr; }
virtual ContextType getContextType() const = 0;
virtual bool isAccelerated() const { return false; }
virtual bool shouldAntialias() const { return false; }
virtual void setIsHidden(bool) = 0;
virtual bool isContextLost() const { return true; }
virtual void setCanvasGetContextResult(RenderingContext&) { NOTREACHED(); };
virtual void setOffscreenCanvasGetContextResult(OffscreenRenderingContext&) {
NOTREACHED();
}
virtual bool isPaintable() const = 0;
// Return true if the content is updated.
virtual bool paintRenderingResultsToCanvas(SourceDrawingBuffer) {
return false;
}
virtual WebLayer* platformLayer() const { return nullptr; }
enum LostContextMode {
NotLostContext,
// Lost context occurred at the graphics system level.
RealLostContext,
// Lost context provoked by WEBGL_lose_context.
WebGLLoseContextLostContext,
// Lost context occurred due to internal implementation reasons.
SyntheticLostContext,
};
virtual void loseContext(LostContextMode) {}
// Canvas2D-specific interface
virtual bool is2d() const { return false; }
virtual void restoreCanvasMatrixClipStack(SkCanvas*) const {}
virtual void reset() {}
virtual void clearRect(double x, double y, double width, double height) {}
virtual void didSetSurfaceSize() {}
virtual void setShouldAntialias(bool) {}
virtual unsigned hitRegionsCount() const { return 0; }
virtual void setFont(const String&) {}
virtual void styleDidChange(const ComputedStyle* oldStyle,
const ComputedStyle& newStyle) {}
virtual HitTestCanvasResult* getControlAndIdIfHitRegionExists(
const LayoutPoint& location) {
NOTREACHED();
return HitTestCanvasResult::create(String(), nullptr);
}
virtual String getIdFromControl(const Element* element) { return String(); }
virtual bool isAccelerationOptimalForCanvasContent() const { return true; }
virtual void resetUsageTracking(){};
virtual void incrementFrameCount(){};
// WebGL-specific interface
virtual bool is3d() const { return false; }
virtual void setFilterQuality(SkFilterQuality) { NOTREACHED(); }
virtual void reshape(int width, int height) { NOTREACHED(); }
virtual void markLayerComposited() { NOTREACHED(); }
virtual ImageData* paintRenderingResultsToImageData(SourceDrawingBuffer) {
NOTREACHED();
return nullptr;
}
virtual int externallyAllocatedBytesPerPixel() {
NOTREACHED();
return 0;
}
// ImageBitmap-specific interface
virtual bool paint(GraphicsContext&, const IntRect&) { return false; }
// OffscreenCanvas-specific methods
OffscreenCanvas* offscreenCanvas() const { return m_offscreenCanvas; }
virtual ImageBitmap* transferToImageBitmap(ScriptState*) { return nullptr; }
bool wouldTaintOrigin(CanvasImageSource*, SecurityOrigin* = nullptr);
void didMoveToNewDocument(Document*);
void detachCanvas() { m_canvas = nullptr; }
void detachOffscreenCanvas() { m_offscreenCanvas = nullptr; }
const CanvasContextCreationAttributes& creationAttributes() const {
return m_creationAttributes;
}
protected:
CanvasRenderingContext(HTMLCanvasElement*,
OffscreenCanvas*,
const CanvasContextCreationAttributes&);
DECLARE_VIRTUAL_TRACE();
virtual void stop() = 0;
private:
void dispose();
Member<HTMLCanvasElement> m_canvas;
Member<OffscreenCanvas> m_offscreenCanvas;
HashSet<String> m_cleanURLs;
HashSet<String> m_dirtyURLs;
CanvasColorSpace m_colorSpace;
CanvasContextCreationAttributes m_creationAttributes;
};
} // namespace blink
#endif
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