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      1 
      2 /*
      3  * Copyright 2011 Google Inc.
      4  *
      5  * Use of this source code is governed by a BSD-style license that can be
      6  * found in the LICENSE file.
      7  */
      8 #ifndef SkImageEncoder_DEFINED
      9 #define SkImageEncoder_DEFINED
     10 
     11 #include "SkTypes.h"
     12 #include "SkTRegistry.h"
     13 
     14 class SkBitmap;
     15 class SkData;
     16 class SkWStream;
     17 
     18 class SkImageEncoder {
     19 public:
     20     enum Type {
     21         kUnknown_Type,
     22         kBMP_Type,
     23         kGIF_Type,
     24         kICO_Type,
     25         kJPEG_Type,
     26         kPNG_Type,
     27         kWBMP_Type,
     28         kWEBP_Type,
     29     };
     30     static SkImageEncoder* Create(Type);
     31 
     32     virtual ~SkImageEncoder();
     33 
     34     /*  Quality ranges from 0..100 */
     35     enum {
     36         kDefaultQuality = 80
     37     };
     38 
     39     /**
     40      *  Encode bitmap 'bm', returning the results in an SkData, at quality level
     41      *  'quality' (which can be in range 0-100). If the bitmap cannot be
     42      *  encoded, return null. On success, the caller is responsible for
     43      *  calling unref() on the data when they are finished.
     44      */
     45     SkData* encodeData(const SkBitmap&, int quality);
     46 
     47     /**
     48      * Encode bitmap 'bm' in the desired format, writing results to
     49      * file 'file', at quality level 'quality' (which can be in range
     50      * 0-100). Returns false on failure.
     51      */
     52     bool encodeFile(const char file[], const SkBitmap& bm, int quality);
     53 
     54     /**
     55      * Encode bitmap 'bm' in the desired format, writing results to
     56      * stream 'stream', at quality level 'quality' (which can be in
     57      * range 0-100). Returns false on failure.
     58      */
     59     bool encodeStream(SkWStream* stream, const SkBitmap& bm, int quality);
     60 
     61     static SkData* EncodeData(const SkBitmap&, Type, int quality);
     62     static bool EncodeFile(const char file[], const SkBitmap&, Type,
     63                            int quality);
     64     static bool EncodeStream(SkWStream*, const SkBitmap&, Type,
     65                            int quality);
     66 
     67 protected:
     68     /**
     69      * Encode bitmap 'bm' in the desired format, writing results to
     70      * stream 'stream', at quality level 'quality' (which can be in
     71      * range 0-100).
     72      *
     73      * This must be overridden by each SkImageEncoder implementation.
     74      */
     75     virtual bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality) = 0;
     76 };
     77 
     78 // This macro declares a global (i.e., non-class owned) creation entry point
     79 // for each encoder (e.g., CreateJPEGImageEncoder)
     80 #define DECLARE_ENCODER_CREATOR(codec)          \
     81     SkImageEncoder *Create ## codec ();
     82 
     83 // This macro defines the global creation entry point for each encoder. Each
     84 // encoder implementation that registers with the encoder factory must call it.
     85 #define DEFINE_ENCODER_CREATOR(codec)           \
     86     SkImageEncoder *Create ## codec () {        \
     87         return SkNEW( Sk ## codec );            \
     88     }
     89 
     90 // All the encoders known by Skia. Note that, depending on the compiler settings,
     91 // not all of these will be available
     92 /** An ARGBImageEncoder will always write out
     93  *  bitmap.width() * bitmap.height() * 4
     94  *  bytes.
     95  */
     96 DECLARE_ENCODER_CREATOR(ARGBImageEncoder);
     97 DECLARE_ENCODER_CREATOR(JPEGImageEncoder);
     98 DECLARE_ENCODER_CREATOR(PNGImageEncoder);
     99 DECLARE_ENCODER_CREATOR(WEBPImageEncoder);
    100 
    101 // Typedef to make registering encoder callback easier
    102 // This has to be defined outside SkImageEncoder. :(
    103 typedef SkTRegistry<SkImageEncoder*(*)(SkImageEncoder::Type)> SkImageEncoder_EncodeReg;
    104 #endif
    105