SkDecodingImageGenerator now uses SkStreamRewindable

src/images/SkDecodingImageGenerator.h

 /*
  * 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 SkDecodingImageGenerator_DEFINED
 #define SkDecodingImageGenerator_DEFINED
 
 #include "SkDiscardableMemory.h"
 #include "SkImageGenerator.h"
+#include "SkImageInfo.h"
 
 class SkBitmap;
+class SkStreamRewindable;
 
 /**
  * Calls into SkImageDecoder::DecodeMemoryToTarget to implement a
  * SkImageGenerator
  */
 class SkDecodingImageGenerator : public SkImageGenerator {
 public:
     /*
      *  The constructor will take a reference to the SkData.  The
      *  destructor will unref() it.
      */
-    SkDecodingImageGenerator(SkData* data);
+    explicit SkDecodingImageGenerator(SkData* data);
+
+    /*
+     *  The SkData version of this constructor is preferred.  If the
+     *  stream has an underlying SkData (such as a SkMemoryStream)
+     *  pass that in.
+     *
+     *  This object will unref the stream when done.  Since streams
+     *  have internal state (position), the caller should not pass a
+     *  shared stream in.  Pass either a new duplicated stream in or
+     *  transfer ownership of the stream.  In the latter case, be sure
+     *  that there are no other consumers of the stream who will
+     *  modify the stream's position.  This constructor asserts
+     *  stream->unique().
+     *
+     *  For example:
+     *    SkStreamRewindable* stream;
+     *    ...
+     *    SkImageGenerator* gen
+     *        = SkNEW_ARGS(SkDecodingImageGenerator,
+     *                     (stream->duplicate()));
+     *    ...
+     *    SkDELETE(gen);
+     */
+    explicit SkDecodingImageGenerator(SkStreamRewindable* stream);
+
     virtual ~SkDecodingImageGenerator();
 
     virtual SkData* refEncodedData() SK_OVERRIDE;
 
     virtual bool getInfo(SkImageInfo* info) SK_OVERRIDE;
 
     virtual bool getPixels(const SkImageInfo& info,
                            void* pixels,
                            size_t rowBytes) SK_OVERRIDE;
 
     /**
      *  Install the SkData into the destination bitmap, using a new
      *  SkDiscardablePixelRef and a new SkDecodingImageGenerator.
      *
      *  @param data Contains the encoded image data that will be used
      *  by the SkDecodingImageGenerator.  Will be ref()ed.
      *
      *  @param destination Upon success, this bitmap will be
      *  configured and have a pixelref installed.
      *
      *  @param factory If not NULL, this object will be used as a
      *  source of discardable memory when decoding.  If NULL, then
      *  SkDiscardableMemory::Create() will be called.
      *
      *  @return true iff successful.
      */
     static bool Install(SkData* data, SkBitmap* destination,
                         SkDiscardableMemory::Factory* factory = NULL);
+    /**
+     *  Install the stream into the destination bitmap, using a new
+     *  SkDiscardablePixelRef and a new SkDecodingImageGenerator.
+     *
+     *  The SkData version of this function is preferred.  If the
+     *  stream has an underlying SkData (such as a SkMemoryStream)
+     *  pass that in.
+     *
+     *  @param stream The source of encoded data that will be passed
+     *  to the decoder.  The installed SkDecodingImageGenerator will
+     *  unref the stream when done.  If false is returned, this
+     *  function will perform the unref.  Since streams have internal
+     *  state (position), the caller should not pass a shared stream
+     *  in.  Pass either a new duplicated stream in or transfer
+     *  ownership of the stream.  In the latter case, be sure that
+     *  there are no other consumers of the stream who will modify the
+     *  stream's position.  This function will fail if
+     *  (!stream->unique()).
+     *
+     *  @param destination Upon success, this bitmap will be
+     *  configured and have a pixelref installed.
+     *
+     *  @param factory If not NULL, this object will be used as a
+     *  source of discardable memory when decoding.  If NULL, then
+     *  SkDiscardableMemory::Create() will be called.
+     *
+     *  @return true iff successful.
+     */
+    static bool Install(SkStreamRewindable* stream, SkBitmap* destination,
+                        SkDiscardableMemory::Factory* factory = NULL);
 
 private:
-    SkData* fData;
+    SkData*             fData;
+    SkStreamRewindable* fStream;
+    SkImageInfo         fInfo;
+    bool                fHasInfo;
+    bool                fDoCopyTo;
 };
 #endif  // SkDecodingImageGenerator_DEFINED