Make SkAndroidCodec support ico

src/codec/SkCodec_libico.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.
  */
 
 #include "SkCodec.h"
 #include "SkImageInfo.h"
 #include "SkStream.h"
@@ skipping 29 matching lines @@
     /*
      * Initiates the Ico decode
      */
     Result onGetPixels(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes, const Options&,
             SkPMColor*, int*, int*) override;
 
     SkEncodedFormat onGetEncodedFormat() const override {
         return kICO_SkEncodedFormat;
     }
 
+    SkScanlineOrder onGetScanlineOrder() const override;
+
 private:
 
+    Result onStartScanlineDecode(const SkImageInfo& dstInfo, const SkCodec::Options& options,
+            SkPMColor inputColorPtr[], int* inputColorCount) override;
+
+    int onGetScanlines(void* dst, int count, size_t rowBytes) override;
+
+    bool onSkipScanlines(int count) override;
+
+    SkSampler* getSampler(bool createIfNecessary) override;
+
+    /*
+     * Searches fEmbeddedCodecs for a codec that matches requestedSize.
+     * The search starts at startIndex and ends when an appropriate codec
+     * is found, or we have reached the end of the SkTArray.

[scroggo, 2015/12/02 16:27:03]

SkTArray is an implementation detail that isn't necessary in this comment.

[msarett, 2015/12/03 19:19:16]

Done.

+     *
+     * @return the index of the matching codec or -1 if there is no
+     *         matching codec between startIndex and the end of
+     *         the SkTArray.
+     */
+    int chooseCodec(const SkISize& requestedSize, int startIndex);
+
     /*
      * Constructor called by NewFromStream
      * @param embeddedCodecs codecs for the embedded images, takes ownership
      */
-    SkIcoCodec(const SkImageInfo& srcInfo,
-               SkTArray<SkAutoTDelete<SkCodec>, true>* embeddedCodecs);
+    SkIcoCodec(const SkImageInfo& srcInfo, SkTArray<SkAutoTDelete<SkCodec>, true>* embeddedCodecs);
 
-    SkAutoTDelete<SkTArray<SkAutoTDelete<SkCodec>, true>>
-            fEmbeddedCodecs; // owned
+    SkAutoTDelete<SkTArray<SkAutoTDelete<SkCodec>, true>> fEmbeddedCodecs; // owned
+
+    // Only used by the scanline decoder.  onStartScanlineDecode() will set
+    // fCodec to one of the fEmbeddedCodecs, if it can find a codec of the
+    // appropriate size.  We will use fCodec for subsequent calls to
+    // onGetScanlines() or onSkipScanlines().
+    // fCodec is owned by this class, but should not be an SkAutoTDelete.
+    // It will be deleted by the destructor of fEmbeddedCodecs.
+    SkCodec* fCodec;

[scroggo, 2015/12/02 16:27:03]

I think this should have a name that indicates that this is used for scanline
decoding (or for an in progress decode). Maybe fCurrScanlineCodec? That's
awfully cumbersome :(

[msarett, 2015/12/03 19:19:16]

Agreed.  fCurrScanlineCodec it is...I can't think of anything better.

 
     typedef SkCodec INHERITED;
 };