| Index: base/scoped_callback_factory.h
|
| ===================================================================
|
| --- base/scoped_callback_factory.h (revision 0)
|
| +++ base/scoped_callback_factory.h (revision 0)
|
| @@ -0,0 +1,133 @@
|
| +// Copyright (c) 2010 The Chromium Authors. All rights reserved.
|
| +// Use of this source code is governed by a BSD-style license that can be
|
| +// found in the LICENSE file.
|
| +
|
| +// ScopedCallbackFactory helps in cases where you wish to allocate a Callback
|
| +// (see base/callback.h), but need to prevent any pending callbacks from
|
| +// executing when your object gets destroyed.
|
| +//
|
| +// EXAMPLE:
|
| +//
|
| +// void GatherDataAsynchronously(Callback1<Data>::Type* callback);
|
| +//
|
| +// class MyClass {
|
| +// public:
|
| +// MyClass() : factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
|
| +// }
|
| +//
|
| +// void Process() {
|
| +// GatherDataAsynchronously(factory_.NewCallback(&MyClass::GotData));
|
| +// }
|
| +//
|
| +// private:
|
| +// void GotData(const Data& data) {
|
| +// ...
|
| +// }
|
| +//
|
| +// base::ScopedCallbackFactory<MyClass> factory_;
|
| +// };
|
| +//
|
| +// In the above example, the Process function calls GatherDataAsynchronously to
|
| +// kick off some asynchronous processing that upon completion will notify a
|
| +// callback. If in the meantime, the MyClass instance is destroyed, when the
|
| +// callback runs, it will notice that the MyClass instance is dead, and it will
|
| +// avoid calling the GotData method.
|
| +
|
| +#ifndef BASE_SCOPED_CALLBACK_FACTORY_H_
|
| +#define BASE_SCOPED_CALLBACK_FACTORY_H_
|
| +
|
| +#include "base/callback.h"
|
| +#include "base/weak_ptr.h"
|
| +
|
| +namespace base {
|
| +
|
| +template <class T>
|
| +class ScopedCallbackFactory {
|
| + public:
|
| + explicit ScopedCallbackFactory(T* obj) : weak_factory_(obj) {
|
| + }
|
| +
|
| + typename Callback0::Type* NewCallback(
|
| + void (T::*method)()) {
|
| + return new CallbackImpl<void (T::*)(), Tuple0 >(
|
| + weak_factory_.GetWeakPtr(), method);
|
| + }
|
| +
|
| + template <typename Arg1>
|
| + typename Callback1<Arg1>::Type* NewCallback(
|
| + void (T::*method)(Arg1)) {
|
| + return new CallbackImpl<void (T::*)(Arg1), Tuple1<Arg1> >(
|
| + weak_factory_.GetWeakPtr(), method);
|
| + }
|
| +
|
| + template <typename Arg1, typename Arg2>
|
| + typename Callback2<Arg1, Arg2>::Type* NewCallback(
|
| + void (T::*method)(Arg1, Arg2)) {
|
| + return new CallbackImpl<void (T::*)(Arg1, Arg2), Tuple2<Arg1, Arg2> >(
|
| + weak_factory_.GetWeakPtr(), method);
|
| + }
|
| +
|
| + template <typename Arg1, typename Arg2, typename Arg3>
|
| + typename Callback3<Arg1, Arg2, Arg3>::Type* NewCallback(
|
| + void (T::*method)(Arg1, Arg2, Arg3)) {
|
| + return new CallbackImpl<void (T::*)(Arg1, Arg2, Arg3),
|
| + Tuple3<Arg1, Arg2, Arg3> >(
|
| + weak_factory_.GetWeakPtr(), method);
|
| + }
|
| +
|
| + template <typename Arg1, typename Arg2, typename Arg3, typename Arg4>
|
| + typename Callback4<Arg1, Arg2, Arg3, Arg4>::Type* NewCallback(
|
| + void (T::*method)(Arg1, Arg2, Arg3, Arg4)) {
|
| + return new CallbackImpl<void (T::*)(Arg1, Arg2, Arg3, Arg4),
|
| + Tuple4<Arg1, Arg2, Arg3, Arg4> >(
|
| + weak_factory_.GetWeakPtr(), method);
|
| + }
|
| +
|
| + template <typename Arg1, typename Arg2, typename Arg3, typename Arg4,
|
| + typename Arg5>
|
| + typename Callback5<Arg1, Arg2, Arg3, Arg4, Arg5>::Type* NewCallback(
|
| + void (T::*method)(Arg1, Arg2, Arg3, Arg4, Arg5)) {
|
| + return new CallbackImpl<void (T::*)(Arg1, Arg2, Arg3, Arg4, Arg5),
|
| + Tuple5<Arg1, Arg2, Arg3, Arg4, Arg5> >(
|
| + weak_factory_.GetWeakPtr(), method);
|
| + }
|
| +
|
| + void RevokeAll() { weak_factory_.InvalidateWeakPtrs(); }
|
| + bool HasPendingCallbacks() const { return weak_factory_.HasWeakPtrs(); }
|
| +
|
| + private:
|
| + template <typename Method>
|
| + class CallbackStorage {
|
| + public:
|
| + CallbackStorage(const WeakPtr<T>& obj, Method meth)
|
| + : obj_(obj),
|
| + meth_(meth) {
|
| + }
|
| +
|
| + protected:
|
| + WeakPtr<T> obj_;
|
| + Method meth_;
|
| + };
|
| +
|
| + template <typename Method, typename Params>
|
| + class CallbackImpl : public CallbackStorage<Method>,
|
| + public CallbackRunner<Params> {
|
| + public:
|
| + CallbackImpl(const WeakPtr<T>& obj, Method meth)
|
| + : CallbackStorage<Method>(obj, meth) {
|
| + }
|
| + virtual void RunWithParams(const Params& params) {
|
| + // Use "this->" to force C++ to look inside our templatized base class;
|
| + // see Effective C++, 3rd Ed, item 43, p210 for details.
|
| + if (!this->obj_)
|
| + return;
|
| + DispatchToMethod(this->obj_.get(), this->meth_, params);
|
| + }
|
| + };
|
| +
|
| + WeakPtrFactory<T> weak_factory_;
|
| +};
|
| +
|
| +} // namespace base
|
| +
|
| +#endif // BASE_SCOPED_CALLBACK_FACTORY_H_
|
|
|
| Property changes on: base\scoped_callback_factory.h
|
| ___________________________________________________________________
|
| Added: svn:eol-style
|
| + LF
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