1 /* 2 * Copyright 2009, The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef SkTRegistry_DEFINED 18 #define SkTRegistry_DEFINED 19 20 #include "SkTypes.h" 21 22 /** Template class that registers itself (in the constructor) into a linked-list 23 and provides a function-pointer. This can be used to auto-register a set of 24 services, e.g. a set of image codecs. 25 */ 26 template <typename T, typename P> class SkTRegistry : SkNoncopyable { 27 public: 28 typedef T (*Factory)(P); 29 30 SkTRegistry(Factory fact) { 31 #ifdef ANDROID 32 // work-around for double-initialization bug 33 { 34 SkTRegistry* reg = gHead; 35 while (reg) { 36 if (reg == this) { 37 return; 38 } 39 reg = reg->fChain; 40 } 41 } 42 #endif 43 fFact = fact; 44 fChain = gHead; 45 gHead = this; 46 } 47 48 static const SkTRegistry* Head() { return gHead; } 49 50 const SkTRegistry* next() const { return fChain; } 51 Factory factory() const { return fFact; } 52 53 private: 54 Factory fFact; 55 SkTRegistry* fChain; 56 57 static SkTRegistry* gHead; 58 }; 59 60 // The caller still needs to declare an instance of this somewhere 61 template <typename T, typename P> SkTRegistry<T, P>* SkTRegistry<T, P>::gHead; 62 63 #endif 64
