1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef SKIA_EXT_LAZY_PIXEL_REF_H_ 6 #define SKIA_EXT_LAZY_PIXEL_REF_H_ 7 8 #include "third_party/skia/include/core/SkPixelRef.h" 9 #include "third_party/skia/include/core/SkRect.h" 10 11 namespace skia { 12 13 // This class extends SkPixelRef to facilitate lazy image decoding on the impl 14 // thread. 15 class SK_API LazyPixelRef : public SkPixelRef { 16 public: 17 explicit LazyPixelRef(const SkImageInfo& info); 18 virtual ~LazyPixelRef(); 19 20 struct PrepareParams { 21 // Clipping rect for this pixel ref. 22 SkIRect clip_rect; 23 }; 24 25 // Request the ImageDecodingStore to prepare image decoding for the 26 // given clipping rect. Returns true is succeeded, or false otherwise. 27 virtual bool PrepareToDecode(const PrepareParams& params) = 0; 28 29 // Returns true if this pixel ref is already in the ImageDecodingStore's 30 // cache, false otherwise. Much cheaper than PrepareToDecode(). 31 virtual bool MaybeDecoded() = 0; 32 33 // Start decoding the image. 34 virtual void Decode() = 0; 35 }; 36 37 } // namespace skia 38 39 #endif // SKIA_EXT_LAZY_PIXEL_REF_H_ 40