halcanary@google.com | ad04eb4 | 2013-11-21 15:32:08 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2013 Google Inc. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license that can be |
| 5 | * found in the LICENSE file. |
| 6 | */ |
| 7 | |
| 8 | #ifndef SkDiscardablePixelRef_DEFINED |
| 9 | #define SkDiscardablePixelRef_DEFINED |
| 10 | |
| 11 | #include "SkPixelRef.h" |
| 12 | #include "SkImageGenerator.h" |
| 13 | #include "SkImageInfo.h" |
| 14 | |
| 15 | class SkDiscardableMemory; |
| 16 | |
| 17 | /** |
| 18 | * An interface that allows a purgable PixelRef to re-decode an image. |
| 19 | */ |
| 20 | |
| 21 | class SkDiscardablePixelRef : public SkPixelRef { |
| 22 | public: |
| 23 | /** |
| 24 | * Takes ownership of SkImageGenerator. If this method fails for |
| 25 | * whatever reason, it will return false and immediatetely delete |
| 26 | * the generator. If it succeeds, it will modify destination |
| 27 | * bitmap. |
| 28 | * |
| 29 | * If Install fails or when the SkDiscardablePixelRef that is |
| 30 | * installed into destination is destroyed, it will call |
| 31 | * SkDELETE() on the generator. Therefore, generator should be |
| 32 | * allocated with SkNEW() or SkNEW_ARGS(). |
| 33 | */ |
| 34 | static bool Install(SkImageGenerator* generator, SkBitmap* destination); |
| 35 | |
| 36 | SK_DECLARE_UNFLATTENABLE_OBJECT() |
| 37 | |
| 38 | protected: |
| 39 | ~SkDiscardablePixelRef(); |
| 40 | virtual void* onLockPixels(SkColorTable**) SK_OVERRIDE; |
| 41 | virtual void onUnlockPixels() SK_OVERRIDE; |
| 42 | virtual bool onLockPixelsAreWritable() const SK_OVERRIDE { return false; } |
| 43 | |
| 44 | virtual SkData* onRefEncodedData() SK_OVERRIDE { |
| 45 | return fGenerator->refEncodedData(); |
| 46 | } |
| 47 | |
| 48 | private: |
| 49 | SkImageGenerator* const fGenerator; |
| 50 | const SkImageInfo fInfo; |
| 51 | const size_t fSize; // size of memory to be allocated |
| 52 | const size_t fRowBytes; |
| 53 | // These const members should not change over the life of the |
| 54 | // PixelRef, since the SkBitmap doesn't expect them to change. |
| 55 | |
| 56 | SkDiscardableMemory* fDiscardableMemory; |
| 57 | |
| 58 | /* Takes ownership of SkImageGenerator. */ |
| 59 | SkDiscardablePixelRef(SkImageGenerator* generator, |
| 60 | const SkImageInfo& info, |
| 61 | size_t size, |
| 62 | size_t rowBytes); |
| 63 | }; |
| 64 | #endif // SkDiscardablePixelRef_DEFINED |