moz-skia/include/core/SkTRegistry.h

64 строки
1.8 KiB
C++

/*
* Copyright 2009, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SkTRegistry_DEFINED
#define SkTRegistry_DEFINED
#include "SkTypes.h"
/** Template class that registers itself (in the constructor) into a linked-list
and provides a function-pointer. This can be used to auto-register a set of
services, e.g. a set of image codecs.
*/
template <typename T, typename P> class SkTRegistry : SkNoncopyable {
public:
typedef T (*Factory)(P);
SkTRegistry(Factory fact) {
#ifdef ANDROID
// work-around for double-initialization bug
{
SkTRegistry* reg = gHead;
while (reg) {
if (reg == this) {
return;
}
reg = reg->fChain;
}
}
#endif
fFact = fact;
fChain = gHead;
gHead = this;
}
static const SkTRegistry* Head() { return gHead; }
const SkTRegistry* next() const { return fChain; }
Factory factory() const { return fFact; }
private:
Factory fFact;
SkTRegistry* fChain;
static SkTRegistry* gHead;
};
// The caller still needs to declare an instance of this somewhere
template <typename T, typename P> SkTRegistry<T, P>* SkTRegistry<T, P>::gHead;
#endif