Updates to skimage tool to use it for testing.

src/images/SkImageDecoder_libico.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkImageDecoder.h"
 #include "SkStream.h"
 #include "SkColorPriv.h"
 #include "SkTypes.h"
 
 class SkICOImageDecoder : public SkImageDecoder {
 public:
     SkICOImageDecoder();
 
     virtual Format getFormat() const SK_OVERRIDE {
         return kICO_Format;
     }
 
+    virtual Format onGetFormat(SkStream*) const SK_OVERRIDE;
+
 protected:
     virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE;
 
 private:
     typedef SkImageDecoder INHERITED;
 };
 
 /////////////////////////////////////////////////////////////////////////////////////////
 
 //read bytes starting from the begin-th index in the buffer
@@ skipping 329 matching lines @@
     int green = readByte(buf, xorOffset + 4*pixelNo + 1);
     int red = readByte(buf, xorOffset + 4*pixelNo + 2);
     int alphaBit = (alphaByte & m) >> shift;
 #if 1 // don't trust the alphaBit for 32bit images <mrr>
     alphaBit = 0;
 #endif
     int alpha = readByte(buf, xorOffset + 4*pixelNo + 3) & ((alphaBit-1)&0xFF);
     *address = SkPreMultiplyARGB(alpha, red, green, blue);
 }
 
-///////////////////////////////////////////////////////////////////////////////
-DEFINE_DECODER_CREATOR(ICOImageDecoder);
-/////////////////////////////////////////////////////////////////////////////////////////
-
-#include "SkTRegistry.h"
-
-static SkImageDecoder* sk_libico_dfactory(SkStream* stream) {
+static bool is_ico(SkStream* stream) {
     // Check to see if the first four bytes are 0,0,1,0
     // FIXME: Is that required and sufficient?
     SkAutoMalloc autoMal(4);
     unsigned char* buf = (unsigned char*)autoMal.get();
     stream->read((void*)buf, 4);
     int reserved = read2Bytes(buf, 0);
     int type = read2Bytes(buf, 2);
     if (reserved != 0 || type != 1) {
         // This stream does not represent an ICO image.
-        return NULL;
+        return false;
     }
-    return SkNEW(SkICOImageDecoder);
+    return true;
+}
+
+SkImageDecoder::Format SkICOImageDecoder::onGetFormat(SkStream* stream) const {
+    if (is_ico(stream)) {
+        return kICO_Format;
+    }
+    return kUnknown_Format;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+DEFINE_DECODER_CREATOR(ICOImageDecoder);
+/////////////////////////////////////////////////////////////////////////////////////////
+
+#include "SkTRegistry.h"
+
+static SkImageDecoder* sk_libico_dfactory(SkStream* stream) {
+    if (is_ico(stream)) {
+        return SkNEW(SkICOImageDecoder);
+    }
+    return NULL;
 }
 
 static SkTRegistry<SkImageDecoder*, SkStream*> gReg(sk_libico_dfactory);