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      1 
      2 /*
      3  * Copyright 2006 The Android Open Source Project
      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 
      9 
     10 #ifndef SkFlattenable_DEFINED
     11 #define SkFlattenable_DEFINED
     12 
     13 #include "SkRefCnt.h"
     14 
     15 class SkReadBuffer;
     16 class SkWriteBuffer;
     17 
     18 #define SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(flattenable) \
     19         SkFlattenable::Registrar(#flattenable, flattenable::CreateProc, \
     20                                  flattenable::GetFlattenableType());
     21 
     22 #define SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP() static void InitializeFlattenables();
     23 
     24 #define SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(flattenable) \
     25     void flattenable::InitializeFlattenables() {
     26 
     27 #define SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END \
     28     }
     29 
     30 #define SK_DECLARE_UNFLATTENABLE_OBJECT() \
     31     virtual Factory getFactory() const SK_OVERRIDE { return NULL; }
     32 
     33 #define SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(flattenable) \
     34     virtual Factory getFactory() const SK_OVERRIDE { return CreateProc; } \
     35     static SkFlattenable* CreateProc(SkReadBuffer& buffer) { \
     36         return SkNEW_ARGS(flattenable, (buffer)); \
     37     }
     38 
     39 /** For SkFlattenable derived objects with a valid type
     40     This macro should only be used in base class objects in core
     41   */
     42 #define SK_DEFINE_FLATTENABLE_TYPE(flattenable) \
     43     static Type GetFlattenableType() { \
     44         return k##flattenable##_Type; \
     45     }
     46 
     47 /** \class SkFlattenable
     48 
     49  SkFlattenable is the base class for objects that need to be flattened
     50  into a data stream for either transport or as part of the key to the
     51  font cache.
     52  */
     53 class SK_API SkFlattenable : public SkRefCnt {
     54 public:
     55     enum Type {
     56         kSkColorFilter_Type,
     57         kSkDrawLooper_Type,
     58         kSkImageFilter_Type,
     59         kSkMaskFilter_Type,
     60         kSkPathEffect_Type,
     61         kSkPixelRef_Type,
     62         kSkRasterizer_Type,
     63         kSkShader_Type,
     64         kSkUnused_Type,     // used to be SkUnitMapper
     65         kSkXfermode_Type,
     66     };
     67 
     68     SK_DECLARE_INST_COUNT(SkFlattenable)
     69 
     70     typedef SkFlattenable* (*Factory)(SkReadBuffer&);
     71 
     72     SkFlattenable() {}
     73 
     74     /** Implement this to return a factory function pointer that can be called
     75      to recreate your class given a buffer (previously written to by your
     76      override of flatten().
     77      */
     78     virtual Factory getFactory() const = 0;
     79 
     80     /** Returns the name of the object's class
     81       */
     82     const char* getTypeName() const { return FactoryToName(getFactory()); }
     83 
     84     static Factory NameToFactory(const char name[]);
     85     static const char* FactoryToName(Factory);
     86     static bool NameToType(const char name[], Type* type);
     87 
     88     static void Register(const char name[], Factory, Type);
     89 
     90     class Registrar {
     91     public:
     92         Registrar(const char name[], Factory factory, Type type) {
     93             SkFlattenable::Register(name, factory, type);
     94         }
     95     };
     96 
     97     /** Override this to write data specific to your subclass into the buffer,
     98      being sure to call your super-class' version first. This data will later
     99      be passed to your Factory function, returned by getFactory().
    100      */
    101     virtual void flatten(SkWriteBuffer&) const;
    102 
    103 protected:
    104     SkFlattenable(SkReadBuffer&) {}
    105 
    106 private:
    107     static void InitializeFlattenablesIfNeeded();
    108 
    109     friend class SkGraphics;
    110 
    111     typedef SkRefCnt INHERITED;
    112 };
    113 
    114 #endif
    115