gecko-dev/dom/canvas/ImageBitmapRenderingContext.h

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3.8 KiB
C++

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef ImageBitmapRenderingContext_h
#define ImageBitmapRenderingContext_h
#include "mozilla/dom/ImageBitmap.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/gfx/DataSurfaceHelpers.h"
#include "mozilla/gfx/Point.h"
#include "mozilla/layers/WebRenderUserData.h"
#include "imgIEncoder.h"
#include "ImageEncoder.h"
#include "nsICanvasRenderingContextInternal.h"
#include "nsWrapperCache.h"
namespace mozilla {
namespace gfx {
class DataSourceSurface;
class DrawTarget;
class SourceSurface;
} // namespace gfx
namespace layers {
class Image;
class ImageContainer;
} // namespace layers
namespace dom {
/**
* The purpose of ImageBitmapRenderingContext is to provide a faster and
* efficient way to display ImageBitmap. Simply call TransferFromImageBitmap()
* then we'll transfer the surface of ImageBitmap to this context and then to
* use it to display.
*
* See more details in spec: https://wiki.whatwg.org/wiki/OffscreenCanvas
*/
class ImageBitmapRenderingContext final
: public nsICanvasRenderingContextInternal,
public nsWrapperCache {
virtual ~ImageBitmapRenderingContext();
public:
ImageBitmapRenderingContext();
virtual JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) override;
// nsISupports interface + CC
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(ImageBitmapRenderingContext)
void GetCanvas(
Nullable<OwningHTMLCanvasElementOrOffscreenCanvas>& retval) const;
void TransferImageBitmap(ImageBitmap& aImageBitmap, ErrorResult& aRv);
void TransferFromImageBitmap(ImageBitmap* aImageBitmap, ErrorResult& aRv);
// nsICanvasRenderingContextInternal
virtual int32_t GetWidth() override { return mWidth; }
virtual int32_t GetHeight() override { return mHeight; }
NS_IMETHOD SetDimensions(int32_t aWidth, int32_t aHeight) override;
NS_IMETHOD InitializeWithDrawTarget(
nsIDocShell* aDocShell, NotNull<gfx::DrawTarget*> aTarget) override;
virtual mozilla::UniquePtr<uint8_t[]> GetImageBuffer(
int32_t* out_format, gfx::IntSize* out_imageSize) override;
NS_IMETHOD GetInputStream(const char* aMimeType,
const nsAString& aEncoderOptions,
nsIInputStream** aStream) override;
virtual already_AddRefed<mozilla::gfx::SourceSurface> GetSurfaceSnapshot(
gfxAlphaType* aOutAlphaType) override;
virtual void SetOpaqueValueFromOpaqueAttr(bool aOpaqueAttrValue) override;
virtual bool GetIsOpaque() override;
void ResetBitmap() override;
virtual already_AddRefed<layers::Image> GetAsImage() override {
return ClipToIntrinsicSize();
}
bool UpdateWebRenderCanvasData(nsDisplayListBuilder* aBuilder,
WebRenderCanvasData* aCanvasData) override;
virtual void MarkContextClean() override;
NS_IMETHOD Redraw(const gfxRect& aDirty) override;
virtual void DidRefresh() override;
void MarkContextCleanForFrameCapture() override {
mFrameCaptureState = FrameCaptureState::CLEAN;
}
Watchable<FrameCaptureState>* GetFrameCaptureState() override {
return &mFrameCaptureState;
}
protected:
already_AddRefed<gfx::DataSourceSurface> MatchWithIntrinsicSize();
already_AddRefed<layers::Image> ClipToIntrinsicSize();
int32_t mWidth;
int32_t mHeight;
RefPtr<layers::Image> mImage;
/**
* Flag to avoid unnecessary surface copies to FrameCaptureListeners in the
* case when the canvas is not currently being drawn into and not rendered
* but canvas capturing is still ongoing.
*/
Watchable<FrameCaptureState> mFrameCaptureState;
};
} // namespace dom
} // namespace mozilla
#endif /* ImageBitmapRenderingContext_h */