gecko-dev/image/AnimationSurfaceProvider.h

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3.8 KiB
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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/. */
/**
* An ISurfaceProvider for animated images.
*/
#ifndef mozilla_image_AnimationSurfaceProvider_h
#define mozilla_image_AnimationSurfaceProvider_h
#include "FrameAnimator.h"
#include "IDecodingTask.h"
#include "ISurfaceProvider.h"
#include "AnimationFrameBuffer.h"
namespace mozilla {
namespace image {
/**
* An ISurfaceProvider that manages the decoding of animated images and
* dynamically generates surfaces for the current playback state of the
* animation.
*/
class AnimationSurfaceProvider final
: public ISurfaceProvider
, public IDecodingTask
{
public:
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(AnimationSurfaceProvider, override)
AnimationSurfaceProvider(NotNull<RasterImage*> aImage,
const SurfaceKey& aSurfaceKey,
NotNull<Decoder*> aDecoder,
size_t aCurrentFrame);
//////////////////////////////////////////////////////////////////////////////
// ISurfaceProvider implementation.
//////////////////////////////////////////////////////////////////////////////
public:
// We use the ISurfaceProvider constructor of DrawableSurface to indicate that
// our surfaces are computed lazily.
DrawableSurface Surface() override { return DrawableSurface(WrapNotNull(this)); }
bool IsFinished() const override;
bool IsFullyDecoded() const override;
size_t LogicalSizeInBytes() const override;
void AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,
size_t& aHeapSizeOut,
size_t& aNonHeapSizeOut,
size_t& aExtHandlesOut) override;
void Reset() override;
void Advance(size_t aFrame) override;
protected:
DrawableFrameRef DrawableRef(size_t aFrame) override;
RawAccessFrameRef RawAccessRef(size_t aFrame) override;
// Animation frames are always locked. This is because we only want to release
// their memory atomically (due to the surface cache discarding them). If they
// were unlocked, the OS could end up releasing the memory of random frames
// from the middle of the animation, which is not worth the complexity of
// dealing with.
bool IsLocked() const override { return true; }
void SetLocked(bool) override { }
//////////////////////////////////////////////////////////////////////////////
// IDecodingTask implementation.
//////////////////////////////////////////////////////////////////////////////
public:
void Run() override;
bool ShouldPreferSyncRun() const override;
// Full decodes are low priority compared to metadata decodes because they
// don't block layout or page load.
TaskPriority Priority() const override { return TaskPriority::eLow; }
private:
virtual ~AnimationSurfaceProvider();
void DropImageReference();
void AnnounceSurfaceAvailable();
void FinishDecoding();
// @returns Whether or not we should continue decoding.
bool CheckForNewFrameAtYield();
// @returns Whether or not we should restart decoding.
bool CheckForNewFrameAtTerminalState();
/// The image associated with our decoder.
RefPtr<RasterImage> mImage;
/// A mutex to protect mDecoder. Always taken before mFramesMutex.
mutable Mutex mDecodingMutex;
/// The decoder used to decode this animation.
RefPtr<Decoder> mDecoder;
/// A mutex to protect mFrames. Always taken after mDecodingMutex.
mutable Mutex mFramesMutex;
/// The frames of this animation, in order.
AnimationFrameBuffer mFrames;
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_AnimationSurfaceProvider_h