michael@0: /*
michael@0:  * Copyright 2013 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #ifndef SkDiscardablePixelRef_DEFINED
michael@0: #define SkDiscardablePixelRef_DEFINED
michael@0: 
michael@0: #include "SkDiscardableMemory.h"
michael@0: #include "SkImageGenerator.h"
michael@0: #include "SkImageInfo.h"
michael@0: #include "SkPixelRef.h"
michael@0: 
michael@0: /**
michael@0:  *  A PixelRef backed by SkDiscardableMemory, with the ability to
michael@0:  *  re-generate the pixels (via a SkImageGenerator) if the DM is
michael@0:  *  purged.
michael@0:  *
michael@0:  *  Since SkColorTable is reference-counted, we do not support indexed
michael@0:  *  color with this class; there would be no way for the discardable
michael@0:  *  memory system to unref the color table.
michael@0:  */
michael@0: class SkDiscardablePixelRef : public SkPixelRef {
michael@0: public:
michael@0:     SK_DECLARE_INST_COUNT(SkDiscardablePixelRef)
michael@0:     SK_DECLARE_UNFLATTENABLE_OBJECT()
michael@0: 
michael@0: protected:
michael@0:     ~SkDiscardablePixelRef();
michael@0: 
michael@0:     virtual bool onNewLockPixels(LockRec*) SK_OVERRIDE;
michael@0:     virtual void onUnlockPixels() SK_OVERRIDE;
michael@0:     virtual bool onLockPixelsAreWritable() const SK_OVERRIDE { return false; }
michael@0: 
michael@0:     virtual SkData* onRefEncodedData() SK_OVERRIDE {
michael@0:         return fGenerator->refEncodedData();
michael@0:     }
michael@0: 
michael@0: private:
michael@0:     SkImageGenerator* const fGenerator;
michael@0:     SkDiscardableMemory::Factory* const fDMFactory;
michael@0:     const size_t fRowBytes;
michael@0:     // These const members should not change over the life of the
michael@0:     // PixelRef, since the SkBitmap doesn't expect them to change.
michael@0: 
michael@0:     SkDiscardableMemory* fDiscardableMemory;
michael@0: 
michael@0:     /* Takes ownership of SkImageGenerator. */
michael@0:     SkDiscardablePixelRef(const SkImageInfo&, SkImageGenerator*,
michael@0:                           size_t rowBytes,
michael@0:                           SkDiscardableMemory::Factory* factory);
michael@0: 
michael@0:     friend bool SkInstallDiscardablePixelRef(SkImageGenerator*,
michael@0:                                              SkBitmap*,
michael@0:                                              SkDiscardableMemory::Factory*);
michael@0: 
michael@0:     typedef SkPixelRef INHERITED;
michael@0: };
michael@0: 
michael@0: #endif  // SkDiscardablePixelRef_DEFINED