blob: b1f2fcd6692b2c7e5297213cac11018d19cdec97 [file] [log] [blame]
/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkCachingPixelRef_DEFINED
#define SkCachingPixelRef_DEFINED
#include "SkImageInfo.h"
#include "SkImageGenerator.h"
#include "SkPixelRef.h"
class SkColorTable;
/**
* PixelRef which defers decoding until SkBitmap::lockPixels() is
* called. Caches the decoded images in the global
* SkScaledImageCache. When the pixels are unlocked, this cache may
* or be destroyed before the next lock. If so, onLockPixels will
* attempt to re-decode.
*
* Decoding is handled by the SkImageGenerator
*/
class SkCachingPixelRef : public SkPixelRef {
public:
/**
* Takes ownership of SkImageGenerator. If this method fails for
* whatever reason, it will return false and immediatetely delete
* the generator. If it succeeds, it will modify destination
* bitmap.
*
* If Install fails or when the SkCachingPixelRef that is
* installed into destination is destroyed, it will call
* SkDELETE() on the generator. Therefore, generator should be
* allocated with SkNEW() or SkNEW_ARGS().
*/
static bool Install(SkImageGenerator* gen, SkBitmap* dst);
protected:
virtual ~SkCachingPixelRef();
virtual void* onLockPixels(SkColorTable** colorTable) SK_OVERRIDE;
virtual void onUnlockPixels() SK_OVERRIDE;
virtual bool onLockPixelsAreWritable() const SK_OVERRIDE { return false; }
virtual SkData* onRefEncodedData() SK_OVERRIDE {
return fImageGenerator->refEncodedData();
}
// No need to flatten this object. When flattening an SkBitmap,
// SkOrderedWriteBuffer will check the encoded data and write that
// instead.
// Future implementations of SkFlattenableWriteBuffer will need to
// special case for onRefEncodedData as well.
SK_DECLARE_UNFLATTENABLE_OBJECT()
private:
SkImageGenerator* const fImageGenerator;
bool fErrorInDecoding;
void* fScaledCacheId;
const size_t fRowBytes;
SkCachingPixelRef(const SkImageInfo&, SkImageGenerator*, size_t rowBytes);
typedef SkPixelRef INHERITED;
};
#endif // SkCachingPixelRef_DEFINED