SkScaledCodec class

src/codec/SkJpegCodec.h

Index: src/codec/SkJpegCodec.h
diff --git a/src/codec/SkJpegCodec.h b/src/codec/SkJpegCodec.h
index 1844269e6b3eff13a2e53dd636a8845e299c8739..505411a14468bd7b2bb6471f2daedaaf49c307ed 100644
--- a/src/codec/SkJpegCodec.h
+++ b/src/codec/SkJpegCodec.h
@@ -59,7 +59,18 @@ protected:
     SkScanlineDecoder* onGetScanlineDecoder(const SkImageInfo& dstInfo, const Options& options,
             SkPMColor ctable[], int* ctableCount) override;
 
+    /*
+     * Checks if we can patially natively scale to the desiredScale, and partially natively scales 
+     * the dimensions if possible.
+     * Returns the new sampleSize, which is used to finish scaling to the desiredScale
+     * Ex: desiredScale = 1/6. Natively can scale by 1/2. New sampleSize = 3, as there is still 
+     * 1/3 scaling left to do, which is done by sampling. 
+     * Returns -1 if partial native scaling is not supported.
+     */
+    int onPartiallyNativelyScale(float desiredScale) override; 
+
 private:
+    SkAutoTDelete<SkSwizzler>   fSwizzler;
 
     /*
      * Read enough of the stream to initialize the SkJpegCodec.
@@ -94,6 +105,11 @@ private:
      */
     SkJpegCodec(const SkImageInfo& srcInfo, SkStream* stream, JpegDecoderMgr* decoderMgr);
 
+    // Helper to set up swizzler.
+    Result initializeSwizzler(const SkImageInfo& requestedInfo, void* dst,
+                              size_t rowBytes, const Options&, SkPMColor*, 
+                              int* ctableCount, int dstWidth);
+
     /*
      * Handles rewinding the input stream if it is necessary
      */
@@ -107,10 +123,10 @@ private:
     bool setOutputColorSpace(const SkImageInfo& dst);
 
     /*
-     * Checks if we can scale to the requested dimensions and scales the dimensions
-     * if possible
+     * Checks if we can natively scale to the requested dimensions and natively scales the 
+     * dimensions if possible
      */
-    bool scaleToDimensions(uint32_t width, uint32_t height);
+    bool nativelyScaleToDimensions(uint32_t width, uint32_t height); 
 
     /*
      * Create the swizzler based on the encoded format
@@ -119,7 +135,8 @@ private:
             const Options& options);
 
     SkAutoTDelete<JpegDecoderMgr> fDecoderMgr;
-
+    int                           fPartialDenom;
+    int                           fPartialNum;
     friend class SkJpegScanlineDecoder;
 
     typedef SkCodec INHERITED;