Adding png scanline decoding to kIndex8

include/codec/SkCodec.h

Index: include/codec/SkCodec.h
diff --git a/include/codec/SkCodec.h b/include/codec/SkCodec.h
index 6f313a1c7058715c8e7c95a82ca1448b152b245e..26134b61ded220abdec797311430a1566bc68c24 100644
--- a/include/codec/SkCodec.h
+++ b/include/codec/SkCodec.h
@@ -70,6 +70,13 @@ public:
      *
      *  @param dstInfo Info of the destination. If the dimensions do not match
      *      those of getInfo, this implies a scale.
+     *  @param options Contains decoding options, including if memory is zero
+     *      initialized.
+     *  @param ctable A pointer to a color table.  This color table will be
+     *      populated if the png has a color palette and we ask to decode in

[scroggo, 2015/04/21 21:43:05]

nit: "we ask to decode in" -> dstInfo.colorType() is

[msarett, 2015/04/22 14:32:52]

Done.

+     *      kIndex8 mode.
+     *  @param ctableCount A pointer to the size of the color table.  Will be
+     *      modified in kIndex8 mode if we have a color palette.

[scroggo, 2015/04/21 21:43:04]

modified to what?

[msarett, 2015/04/22 14:32:52]

Done.

      *  @return New SkScanlineDecoder, or NULL on failure.
      *
      *  NOTE: If any rows were previously decoded, this requires rewinding the
@@ -78,7 +85,8 @@ public:
      *  NOTE: The scanline decoder is owned by the SkCodec and will delete it
      *  when the SkCodec is deleted.
      */
-    SkScanlineDecoder* getScanlineDecoder(const SkImageInfo& dstInfo);
+    SkScanlineDecoder* getScanlineDecoder(const SkImageInfo& dstInfo, const Options* options,

[scroggo, 2015/04/21 21:43:05]

Should we have a version that does not take Options or color table stuff, like
getPixels?

[msarett, 2015/04/22 14:32:52]

I have added this version.

+                                          SkPMColor ctable[], int* ctableCount);
 
     /**
      *  Some images may initially report that they have alpha due to the format
@@ -126,10 +134,20 @@ protected:
      *
      *  @param dstInfo Info of the destination. If the dimensions do not match
      *      those of getInfo, this implies a scale.
+     *  @param options Contains decoding options, including if memory is zero
+     *      initialized.
+     *  @param ctable A pointer to a color table.  This color table will be
+     *      populated if the png has a color palette and we ask to decode in

[scroggo, 2015/04/21 21:43:05]

same wording nit.

[msarett, 2015/04/22 14:32:52]

Done.

+     *      kIndex8 mode.
+     *  @param ctableCount A pointer to the size of the color table.  Will be
+     *      modified in kIndex8 mode if we have a color palette.

[scroggo, 2015/04/21 21:43:05]

same question

[msarett, 2015/04/22 14:32:52]

Done.

      *  @return New SkScanlineDecoder on success, NULL otherwise. The SkCodec
      *      will take ownership of the returned scanline decoder.
      */
-    virtual SkScanlineDecoder* onGetScanlineDecoder(const SkImageInfo& dstInfo) {
+    virtual SkScanlineDecoder* onGetScanlineDecoder(const SkImageInfo& dstInfo,
+                                                    const Options& options,
+                                                    SkPMColor ctable[],
+                                                    int* ctableCount) {
         return NULL;
     }