| // Copyright (c) 2012 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. |
| |
| // This defines helpful methods for dealing with Callbacks. Because Callbacks |
| // are implemented using templates, with a class per callback signature, adding |
| // methods to Callback<> itself is unattractive (lots of extra code gets |
| // generated). Instead, consider adding methods here. |
| // |
| // ResetAndReturn(&cb) is like cb.Reset() but allows executing a callback (via a |
| // copy) after the original callback is Reset(). This can be handy if Run() |
| // reads/writes the variable holding the Callback. |
| |
| #ifndef BASE_CALLBACK_HELPERS_H_ |
| #define BASE_CALLBACK_HELPERS_H_ |
| |
| #include "base/basictypes.h" |
| #include "base/callback.h" |
| #include "base/compiler_specific.h" |
| |
| namespace base { |
| |
| template <typename Sig> |
| base::Callback<Sig> ResetAndReturn(base::Callback<Sig>* cb) { |
| base::Callback<Sig> ret(*cb); |
| cb->Reset(); |
| return ret; |
| } |
| |
| // ScopedClosureRunner is akin to scoped_ptr for Closures. It ensures that the |
| // Closure is executed and deleted no matter how the current scope exits. |
| class BASE_EXPORT ScopedClosureRunner { |
| public: |
| ScopedClosureRunner(); |
| explicit ScopedClosureRunner(const Closure& closure); |
| ~ScopedClosureRunner(); |
| |
| void Reset(); |
| void Reset(const Closure& closure); |
| Closure Release() WARN_UNUSED_RESULT; |
| |
| private: |
| Closure closure_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ScopedClosureRunner); |
| }; |
| |
| } // namespace base |
| |
| #endif // BASE_CALLBACK_HELPERS_H_ |