Scanline decoding for bmp

src/codec/SkBmpCodec.h

Index: src/codec/SkBmpCodec.h
diff --git a/src/codec/SkBmpCodec.h b/src/codec/SkBmpCodec.h
index 71006f73153ea3028529b0c51daa999b498bc86e..c187b31271eebfbeba85c7816c100720c46b7bf2 100644
--- a/src/codec/SkBmpCodec.h
+++ b/src/codec/SkBmpCodec.h
@@ -11,6 +11,7 @@
 #include "SkColorTable.h"
 #include "SkImageInfo.h"
 #include "SkMaskSwizzler.h"
+#include "SkScanlineDecoder.h"
 #include "SkStream.h"
 #include "SkSwizzler.h"
 #include "SkTypes.h"
@@ -31,6 +32,16 @@ public:
     };
 
     /*
+     * Used to define the input format of the bmp
+     */
+    enum BmpInputFormat {
+        kStandard_BmpInputFormat,
+        kRLE_BmpInputFormat,
+        kBitMask_BmpInputFormat,
+        kUnknown_BmpInputFormat
+    };
+
+    /*
      * Checks the start of the stream to see if the image is a bmp
      */
     static bool IsBmp(SkStream*);
@@ -48,6 +59,13 @@ public:
      */
     static SkCodec* NewFromIco(SkStream*);
 
+    /*
+     * Assumes IsBmp was called and returned true
+     * Creates a bmp scanline decoder
+     * Takes ownership of the stream
+     */
+    static SkScanlineDecoder* NewSDFromStream(SkStream* stream);
+
 protected:
 
     SkBmpCodec(const SkImageInfo& info, SkStream* stream, uint16_t bitsPerPixel,
@@ -104,8 +122,23 @@ private:
      */
     static SkCodec* NewFromStream(SkStream*, bool inIco);
 
-    const uint16_t fBitsPerPixel;
-    const RowOrder fRowOrder;
+    /*
+     * Calls unique bmp subclass implementations of onStart()
+     */
+    virtual SkCodec::Result onStart(const SkImageInfo& dstInfo, const SkCodec::Options& options,
+            SkPMColor inputColorPtr[], int* inputColorCount) = 0;
+
+    /*
+     * Performs the row by row decode
+     * Unique for each of the bmp subclasses
+     */
+    virtual Result decode(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes,
+            const Options& opts) = 0;
+
+    const uint16_t       fBitsPerPixel;
+    const RowOrder       fRowOrder;
+
+    friend class SkBmpScanlineDecoder;
 
     typedef SkCodec INHERITED;
 };