skia2/include/core/SkFlattenable.h
mdempsky 00d6e515e5 Eliminate some clutter in SkFlattenable
The Registrar class is unnecessary, as SkFlattenable factory
registration is now handled via initialization routines that can just
call the Register function directly.

Also, no need to lazily initialize gCount to 0, as initializing an int
to a constant value does not require dynamic initialization.  (C++
actually guarantees zero initialization of global ints anyway, but
existing practice in Skia appears to favor the explicit "= 0").

Relatedly, this requires removing the unused/unimplemented
SkLayerDrawLooper::MyRegistrar class.  And removing that allows Clang
to realize that SkLayerDrawLooper::fTopRec is unneeded too, so remove
that too to squelch the compiler warning/error.

This doesn't change any public API.
TBR=reed@google.com

Review URL: https://codereview.chromium.org/1361323002
2015-09-24 15:04:45 -07:00

120 lines
3.9 KiB
C++

/*
* 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.
*/
#ifndef SkFlattenable_DEFINED
#define SkFlattenable_DEFINED
#include "SkRefCnt.h"
class SkReadBuffer;
class SkWriteBuffer;
class SkPrivateEffectInitializer;
/*
* Flattening is straight-forward:
* 1. call getFactory() so we have a function-ptr to recreate the subclass
* 2. call flatten(buffer) to write out enough data for the factory to read
*
* Unflattening is easy for the caller: new_instance = factory(buffer)
*
* The complexity of supporting this is as follows.
*
* If your subclass wants to control unflattening, use this macro in your declaration:
* SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS
* This will provide a getFactory(), and require that the subclass implements CreateProc.
*
* For older buffers (before the DEEPFLATTENING change, the macros below declare
* a thin factory DeepCreateProc. It checks the version of the buffer, and if it is pre-deep,
* then it calls through to a (usually protected) constructor, passing the buffer.
* If the buffer is newer, then it directly calls the "real" factory: CreateProc.
*/
#define SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP() static void InitializeFlattenables();
#define SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(flattenable) \
void flattenable::InitializeFlattenables() {
#define SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END \
}
#define SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(flattenable) \
SkFlattenable::Register(#flattenable, flattenable::CreateProc, \
flattenable::GetFlattenableType());
#define SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(flattenable) \
private: \
static SkFlattenable* CreateProc(SkReadBuffer&); \
friend class ::SkPrivateEffectInitializer; \
public: \
Factory getFactory() const override { return CreateProc; }
/** For SkFlattenable derived objects with a valid type
This macro should only be used in base class objects in core
*/
#define SK_DEFINE_FLATTENABLE_TYPE(flattenable) \
static Type GetFlattenableType() { \
return k##flattenable##_Type; \
}
/** \class SkFlattenable
SkFlattenable is the base class for objects that need to be flattened
into a data stream for either transport or as part of the key to the
font cache.
*/
class SK_API SkFlattenable : public SkRefCnt {
public:
enum Type {
kSkColorFilter_Type,
kSkDrawLooper_Type,
kSkImageFilter_Type,
kSkMaskFilter_Type,
kSkPathEffect_Type,
kSkPixelRef_Type,
kSkRasterizer_Type,
kSkShader_Type,
kSkUnused_Type, // used to be SkUnitMapper
kSkXfermode_Type,
};
typedef SkFlattenable* (*Factory)(SkReadBuffer&);
SkFlattenable() {}
/** Implement this to return a factory function pointer that can be called
to recreate your class given a buffer (previously written to by your
override of flatten().
*/
virtual Factory getFactory() const = 0;
/** Returns the name of the object's class
*/
const char* getTypeName() const { return FactoryToName(getFactory()); }
static Factory NameToFactory(const char name[]);
static const char* FactoryToName(Factory);
static bool NameToType(const char name[], Type* type);
static void Register(const char name[], Factory, Type);
/**
* Override this if your subclass needs to record data that it will need to recreate itself
* from its CreateProc (returned by getFactory()).
*/
virtual void flatten(SkWriteBuffer&) const {}
private:
static void InitializeFlattenablesIfNeeded();
friend class SkGraphics;
typedef SkRefCnt INHERITED;
};
#endif