| /* |
| * 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 "SkImage.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 pure-virtual functions onDecodeInfo() |
| * and onDecodePixels(). Subclasses of this class need only provide |
| * those two functions. |
| */ |
| class SkCachingPixelRef : public SkPixelRef { |
| public: |
| SkCachingPixelRef(); |
| virtual ~SkCachingPixelRef(); |
| |
| protected: |
| virtual void* onLockPixels(SkColorTable** colorTable) SK_OVERRIDE; |
| virtual void onUnlockPixels() SK_OVERRIDE; |
| virtual bool onLockPixelsAreWritable() const SK_OVERRIDE { return false; } |
| virtual bool onImplementsDecodeInto() SK_OVERRIDE { return true; } |
| virtual bool onDecodeInto(int pow2, SkBitmap*) SK_OVERRIDE; |
| |
| /** |
| * Configure the supplied bitmap for this pixelRef, based on |
| * information provided by onDecodeInfo(). Does not set the |
| * bitmap's pixelRef. */ |
| bool configure(SkBitmap* bitmap); |
| |
| /** |
| * Cache info from onDecodeInfo(). Returns false on failure. |
| */ |
| bool getInfo(SkImageInfo* info); |
| |
| /** |
| * Return some information about the pixels, allowing this class |
| * to allocate pixels. @return false if anything goes wrong. |
| */ |
| virtual bool onDecodeInfo(SkImageInfo* info) = 0; |
| /** |
| * Decode into the given pixels, a block of memory of size |
| * (info.fHeight - 1) * rowBytes + (info.fWidth * bytesPerPixel) |
| * |
| * @param info Should be identical to the info returned by |
| * onDecodeInfo so that the implementation can confirm |
| * that the caller knows what it is asking for (config, |
| * size). Thiscontract also allows the caller to specify |
| * different output-configs, which the implementation can |
| * decide to support or not. |
| * |
| * @return false if anything goes wrong. |
| */ |
| virtual bool onDecodePixels(const SkImageInfo& info, |
| void* pixels, |
| size_t rowBytes) = 0; |
| |
| private: |
| bool fErrorInDecoding; |
| void* fScaledCacheId; |
| SkImageInfo fInfo; |
| |
| typedef SkPixelRef INHERITED; |
| }; |
| |
| #endif // SkCachingPixelRef_DEFINED |
| |