Add currScanline() getter to SkCodec API

include/codec/SkCodec.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkCodec_DEFINED
 #define SkCodec_DEFINED
 
@@ skipping 495 matching lines @@
      */
 
     /**
      *  Most images types will be kTopDown and will not need to override this function.
      */
     virtual SkScanlineOrder onGetScanlineOrder() const { return kTopDown_SkScanlineOrder; }
 
     /**
      *  Update the next scanline. Used by interlaced png.
      */
     void updateNextScanline(int newY) { fCurrScanline = newY; }

[scroggo, 2015/12/02 15:24:41]

Maybe this should be updateCurrScanline, to match currScanline? (It currently
matches nextScanline, but really it seems more analogous to currScanline.)

[msarett, 2015/12/02 15:45:05]

Agreed.

 
     const SkImageInfo& dstInfo() const { return fDstInfo; }
 
     const SkCodec::Options& options() const { return fOptions; }
 
+    int currScanline() const { return fCurrScanline; }

[scroggo, 2015/12/02 15:24:41]

Add some comments? We now have:

currScanline()
nextScanline()
outputScanline()

It would be nice to distinguish them.

[msarett, 2015/12/02 15:45:05]

Yes this is confusing will do.

+
     virtual int onOutputScanline(int inputScanline) const;
 
 private:
     const SkImageInfo       fSrcInfo;
     SkAutoTDelete<SkStream> fStream;
     bool                    fNeedsRewind;
     // These fields are only meaningful during scanline decodes.
     SkImageInfo             fDstInfo;
     SkCodec::Options        fOptions;
     int                     fCurrScanline;
@@ skipping 55 matching lines @@
      *  May create a sampler, if one is not currently being used. Otherwise, does
      *  not affect ownership.
      *
      *  Only valid during scanline decoding.
      */
     virtual SkSampler* getSampler(bool /*createIfNecessary*/) { return nullptr; }
 
     friend class SkSampledCodec;
 };
 #endif // SkCodec_DEFINED