new API for retrieving YUV data

src/images/SkDecodingImageGenerator.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkData.h"
 #include "SkDecodingImageGenerator.h"
 #include "SkImageDecoder.h"
@@ skipping 24 matching lines @@
                            const SkImageInfo& info,
                            int sampleSize,
                            bool ditherImage);
 
 protected:
     SkData* onRefEncodedData() SK_OVERRIDE;
     bool onGetInfo(SkImageInfo* info) SK_OVERRIDE {
         *info = fInfo;
         return true;
     }
-    virtual bool onGetPixels(const SkImageInfo& info,
-                             void* pixels, size_t rowBytes,
-                             SkPMColor ctable[], int* ctableCount) SK_OVERRIDE;
-    virtual bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3],
-                                 SkYUVColorSpace* colorSpace) SK_OVERRIDE;
+    bool onGetPixels(const SkImageInfo&, void* pixels, size_t rowBytes, SkPMColor ctable[],
+                     int* ctableCount) SK_OVERRIDE;
+    bool onQueryYUV8(SkISize logical[3], SkISize optimal[3]) SK_OVERRIDE;
+    bool onGetYUV8(const SkISize sizes[3], void* planes[3], SkYUVColorSpace*) SK_OVERRIDE;
 
 private:
     typedef SkImageGenerator INHERITED;
 };
 
 /**
  *  Special allocator used by getPixels(). Uses preallocated memory
  *  provided if possible, else fall-back on the default allocator
  */
 class TargetAllocator : public SkBitmap::Allocator {
@@ skipping 137 matching lines @@
         if (NULL == ctable) {
             return false;
         }
         const int count = ctable->count();
         memcpy(ctableEntries, ctable->readColors(), count * sizeof(SkPMColor));
         *ctableCount = count;
     }
     return true;
 }
 
-bool DecodingImageGenerator::onGetYUV8Planes(SkISize sizes[3], void* planes[3],
-                                             size_t rowBytes[3], SkYUVColorSpace* colorSpace) {
+bool DecodingImageGenerator::onQueryYUV8(SkISize logical[3], SkISize optimal[3]) {
     if (!fStream->rewind()) {
         return false;
     }
 
     SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(fStream));
     if (NULL == decoder.get()) {
         return false;
     }
 
-    return decoder->decodeYUV8Planes(fStream, sizes, planes, rowBytes, colorSpace);
+    return false;//decoder->decodeYUV8Planes(fStream, sizes, planes, rowBytes, colorSpace);
 }
 
+bool DecodingImageGenerator::onGetYUV8(const SkISize sizes[3], void* planes[3],
+                                       SkYUVColorSpace* colorSpace) {
+    if (!fStream->rewind()) {
+        return false;
+    }
+
+    SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(fStream));
+    if (NULL == decoder.get()) {
+        return false;
+    }
+
+    return false;//decoder->decodeYUV8Planes(fStream, sizes, planes, rowBytes, colorSpace);
+}
+    
 // A contructor-type function that returns NULL on failure.  This
 // prevents the returned SkImageGenerator from ever being in a bad
 // state.  Called by both Create() functions
 SkImageGenerator* CreateDecodingImageGenerator(
         SkData* data,
         SkStreamRewindable* stream,
         const SkDecodingImageGenerator::Options& opts) {
     SkASSERT(stream);
     SkAutoTDelete<SkStreamRewindable> autoStream(stream);  // always delete this
     SkAssertResult(autoStream->rewind());
@@ skipping 53 matching lines @@
 
 SkImageGenerator* SkDecodingImageGenerator::Create(
         SkStreamRewindable* stream,
         const SkDecodingImageGenerator::Options& opts) {
     SkASSERT(stream != NULL);
     if (stream == NULL) {
         return NULL;
     }
     return CreateDecodingImageGenerator(NULL, stream, opts);
 }