1 /* 2 * Copyright 2009 The Android Open Source Project 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef sk_tools_Registry_DEFINED 9 #define sk_tools_Registry_DEFINED 10 11 #include "SkTypes.h" 12 13 namespace sk_tools { 14 15 /** Template class that registers itself (in the constructor) into a linked-list 16 and provides a function-pointer. This can be used to auto-register a set of 17 services, e.g. a set of image codecs. 18 */ 19 template <typename T> class Registry : SkNoncopyable { 20 public: 21 typedef T Factory; 22 23 explicit Registry(T fact) : fFact(fact) { 24 #ifdef SK_BUILD_FOR_ANDROID 25 // work-around for double-initialization bug 26 { 27 Registry* reg = gHead; 28 while (reg) { 29 if (reg == this) { 30 return; 31 } 32 reg = reg->fChain; 33 } 34 } 35 #endif 36 fChain = gHead; 37 gHead = this; 38 } 39 40 static const Registry* Head() { return gHead; } 41 42 const Registry* next() const { return fChain; } 43 const Factory& factory() const { return fFact; } 44 45 private: 46 Factory fFact; 47 Registry* fChain; 48 49 static Registry* gHead; 50 }; 51 52 // The caller still needs to declare an instance of this somewhere 53 template <typename T> Registry<T>* Registry<T>::gHead; 54 55 } // namespace sk_tools 56 57 #endif 58
