formalize generate->bitmap

include/core/SkImageGenerator.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 SkImageGenerator_DEFINED
 #define SkImageGenerator_DEFINED
 
@@ skipping 147 matching lines @@
     static SkImageGenerator* NewFromEncoded(SkData*);
 
     /** Return a new image generator backed by the specified picture.  If the size is empty or
      *  the picture is NULL, this returns NULL.
      *  The optional matrix and paint arguments are passed to drawPicture() at rasterization
      *  time.
      */
     static SkImageGenerator* NewFromPicture(const SkISize&, const SkPicture*, const SkMatrix*,
                                             const SkPaint*);
 
+    bool tryGenerateBitmap(SkBitmap* bm) {
+        return this->tryGenerateBitmap(bm, nullptr);
+    }
+    bool tryGenerateBitmap(SkBitmap* bm, const SkImageInfo& info) {
+        return this->tryGenerateBitmap(bm, &info);
+    }
+    void generateBitmap(SkBitmap* bm) {
+        if (!this->tryGenerateBitmap(bm, nullptr)) {
+            sk_throw();
+        }
+    }
+    void generateBitmap(SkBitmap* bm, const SkImageInfo& info) {
+        if (!this->tryGenerateBitmap(bm, &info)) {
+            sk_throw();
+        }
+    }
+
 protected:
     SkImageGenerator(const SkImageInfo& info);
 
     virtual SkData* onRefEncodedData();
 
     virtual bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
                              SkPMColor ctable[], int* ctableCount);
     virtual bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3]);
     virtual bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3],
                                  SkYUVColorSpace* colorSpace);
 
     virtual GrTexture* onGenerateTexture(GrContext*, SkImageUsageType, const SkIRect*) {
         return nullptr;
     }
 
+    bool tryGenerateBitmap(SkBitmap* bm, const SkImageInfo* optionalInfo);
+
 private:
     const SkImageInfo fInfo;
     const uint32_t fUniqueID;
 
     // This is our default impl, which may be different on different platforms.
     // It is called from NewFromEncoded() after it has checked for any runtime factory.
     // The SkData will never be NULL, as that will have been checked by NewFromEncoded.
     static SkImageGenerator* NewFromEncodedImpl(SkData*);
 };
 
 #endif  // SkImageGenerator_DEFINED