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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 MOZILLA_DOM_OFFSCREENCANVAS_H_
#define MOZILLA_DOM_OFFSCREENCANVAS_H_
#include "mozilla/DOMEventTargetHelper.h"
#include "mozilla/layers/LayersTypes.h"
#include "mozilla/RefPtr.h"
#include "CanvasRenderingContextHelper.h"
#include "nsCycleCollectionParticipant.h"
struct JSContext;
namespace mozilla {
class ErrorResult;
namespace layers {
class AsyncCanvasRenderer;
class CanvasClient;
} // namespace layers
namespace dom {
class Blob;
class ImageBitmap;
// This is helper class for transferring OffscreenCanvas to worker thread.
// Because OffscreenCanvas is not thread-safe. So we cannot pass Offscreen-
// Canvas to worker thread directly. Thus, we create this helper class and
// store necessary data in it then pass it to worker thread.
struct OffscreenCanvasCloneData final
{
OffscreenCanvasCloneData(layers::AsyncCanvasRenderer* aRenderer,
uint32_t aWidth, uint32_t aHeight,
layers::LayersBackend aCompositorBackend,
bool aNeutered, bool aIsWriteOnly);
~OffscreenCanvasCloneData();
RefPtr<layers::AsyncCanvasRenderer> mRenderer;
uint32_t mWidth;
uint32_t mHeight;
layers::LayersBackend mCompositorBackendType;
bool mNeutered;
bool mIsWriteOnly;
};
class OffscreenCanvas final : public DOMEventTargetHelper
, public CanvasRenderingContextHelper
{
public:
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(OffscreenCanvas, DOMEventTargetHelper)
OffscreenCanvas(nsIGlobalObject* aGlobal,
uint32_t aWidth,
uint32_t aHeight,
layers::LayersBackend aCompositorBackend,
layers::AsyncCanvasRenderer* aRenderer);
nsCOMPtr<nsIGlobalObject> GetParentObject() const { return GetOwnerGlobal(); }
virtual JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) override;
static already_AddRefed<OffscreenCanvas>
Constructor(const GlobalObject& aGlobal,
uint32_t aWidth,
uint32_t aHeight,
ErrorResult& aRv);
void ClearResources();
uint32_t Width() const
{
return mWidth;
}
uint32_t Height() const
{
return mHeight;
}
void SetWidth(uint32_t aWidth, ErrorResult& aRv)
{
if (mNeutered) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
if (mWidth != aWidth) {
mWidth = aWidth;
CanvasAttrChanged();
}
}
void SetHeight(uint32_t aHeight, ErrorResult& aRv)
{
if (mNeutered) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
if (mHeight != aHeight) {
mHeight = aHeight;
CanvasAttrChanged();
}
}
already_AddRefed<ImageBitmap>
TransferToImageBitmap();
already_AddRefed<Promise>
ToBlob(JSContext* aCx,
const nsAString& aType,
JS::Handle<JS::Value> aParams,
ErrorResult& aRv);
nsICanvasRenderingContextInternal* GetContext() const
{
return mCurrentContext;
}
already_AddRefed<gfx::SourceSurface> GetSurfaceSnapshot(bool* aPremultAlpha = nullptr);
static already_AddRefed<OffscreenCanvas>
CreateFromCloneData(nsIGlobalObject* aGlobal, OffscreenCanvasCloneData* aData);
static bool PrefEnabled(JSContext* aCx, JSObject* aObj);
// Return true on main-thread, and return gfx.offscreencanvas.enabled
// on worker thread.
static bool PrefEnabledOnWorkerThread(JSContext* aCx, JSObject* aObj);
OffscreenCanvasCloneData* ToCloneData();
void CommitFrameToCompositor();
virtual bool GetOpaqueAttr() override
{
return false;
}
virtual nsIntSize GetWidthHeight() override
{
return nsIntSize(mWidth, mHeight);
}
virtual already_AddRefed<nsICanvasRenderingContextInternal>
CreateContext(CanvasContextType aContextType) override;
virtual already_AddRefed<nsISupports>
GetContext(JSContext* aCx,
const nsAString& aContextId,
JS::Handle<JS::Value> aContextOptions,
ErrorResult& aRv) override;
void SetNeutered()
{
mNeutered = true;
}
bool IsNeutered() const
{
return mNeutered;
}
void SetWriteOnly()
{
mIsWriteOnly = true;
}
bool IsWriteOnly() const
{
return mIsWriteOnly;
}
layers::LayersBackend GetCompositorBackendType() const
{
return mCompositorBackendType;
}
private:
~OffscreenCanvas();
nsCOMPtr<nsIGlobalObject> GetGlobalObject();
void CanvasAttrChanged()
{
mAttrDirty = true;
ErrorResult dummy;
UpdateContext(nullptr, JS::NullHandleValue, dummy);
}
bool mAttrDirty;
bool mNeutered;
bool mIsWriteOnly;
uint32_t mWidth;
uint32_t mHeight;
layers::LayersBackend mCompositorBackendType;
RefPtr<layers::CanvasClient> mCanvasClient;
RefPtr<layers::AsyncCanvasRenderer> mCanvasRenderer;
};
} // namespace dom
} // namespace mozilla
#endif // MOZILLA_DOM_OFFSCREENCANVAS_H_
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