1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/include/core/SkImageGenerator.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,101 @@
1.4 +/*
1.5 + * Copyright 2013 Google Inc.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#ifndef SkImageGenerator_DEFINED
1.12 +#define SkImageGenerator_DEFINED
1.13 +
1.14 +#include "SkDiscardableMemory.h"
1.15 +#include "SkImageInfo.h"
1.16 +
1.17 +class SkBitmap;
1.18 +class SkData;
1.19 +class SkImageGenerator;
1.20 +
1.21 +/**
1.22 + * Takes ownership of SkImageGenerator. If this method fails for
1.23 + * whatever reason, it will return false and immediatetely delete
1.24 + * the generator. If it succeeds, it will modify destination
1.25 + * bitmap.
1.26 + *
1.27 + * If generator is NULL, will safely return false.
1.28 + *
1.29 + * If this fails or when the SkDiscardablePixelRef that is
1.30 + * installed into destination is destroyed, it will call
1.31 + * SkDELETE() on the generator. Therefore, generator should be
1.32 + * allocated with SkNEW() or SkNEW_ARGS().
1.33 + *
1.34 + * @param destination Upon success, this bitmap will be
1.35 + * configured and have a pixelref installed.
1.36 + *
1.37 + * @param factory If not NULL, this object will be used as a
1.38 + * source of discardable memory when decoding. If NULL, then
1.39 + * SkDiscardableMemory::Create() will be called.
1.40 + *
1.41 + * @return true iff successful.
1.42 + */
1.43 +SK_API bool SkInstallDiscardablePixelRef(SkImageGenerator* generator,
1.44 + SkBitmap* destination,
1.45 + SkDiscardableMemory::Factory* factory = NULL);
1.46 +
1.47 +
1.48 +/**
1.49 + * An interface that allows a purgeable PixelRef (such as a
1.50 + * SkDiscardablePixelRef) to decode and re-decode an image as needed.
1.51 + */
1.52 +class SK_API SkImageGenerator {
1.53 +public:
1.54 + /**
1.55 + * The PixelRef which takes ownership of this SkImageGenerator
1.56 + * will call the image generator's destructor.
1.57 + */
1.58 + virtual ~SkImageGenerator() { }
1.59 +
1.60 + /**
1.61 + * Return a ref to the encoded (i.e. compressed) representation,
1.62 + * of this data.
1.63 + *
1.64 + * If non-NULL is returned, the caller is responsible for calling
1.65 + * unref() on the data when it is finished.
1.66 + */
1.67 + virtual SkData* refEncodedData() { return NULL; }
1.68 +
1.69 + /**
1.70 + * Return some information about the image, allowing the owner of
1.71 + * this object to allocate pixels.
1.72 + *
1.73 + * Repeated calls to this function should give the same results,
1.74 + * allowing the PixelRef to be immutable.
1.75 + *
1.76 + * @return false if anything goes wrong.
1.77 + */
1.78 + virtual bool getInfo(SkImageInfo* info) = 0;
1.79 +
1.80 + /**
1.81 + * Decode into the given pixels, a block of memory of size at
1.82 + * least (info.fHeight - 1) * rowBytes + (info.fWidth *
1.83 + * bytesPerPixel)
1.84 + *
1.85 + * Repeated calls to this function should give the same results,
1.86 + * allowing the PixelRef to be immutable.
1.87 + *
1.88 + * @param info A description of the format (config, size)
1.89 + * expected by the caller. This can simply be identical
1.90 + * to the info returned by getInfo().
1.91 + *
1.92 + * This contract also allows the caller to specify
1.93 + * different output-configs, which the implementation can
1.94 + * decide to support or not.
1.95 + *
1.96 + * @return false if anything goes wrong or if the image info is
1.97 + * unsupported.
1.98 + */
1.99 + virtual bool getPixels(const SkImageInfo& info,
1.100 + void* pixels,
1.101 + size_t rowBytes) = 0;
1.102 +};
1.103 +
1.104 +#endif // SkImageGenerator_DEFINED
