fischman@chromium.org | dc221a7 | 2012-03-25 05:37:27 +0900 | [diff] [blame] | 1 | // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | // This defines helpful methods for dealing with Callbacks. Because Callbacks |
| 6 | // are implemented using templates, with a class per callback signature, adding |
| 7 | // methods to Callback<> itself is unattractive (lots of extra code gets |
| 8 | // generated). Instead, consider adding methods here. |
| 9 | // |
| 10 | // ResetAndReturn(&cb) is like cb.Reset() but allows executing a callback (via a |
| 11 | // copy) after the original callback is Reset(). This can be handy if Run() |
| 12 | // reads/writes the variable holding the Callback. |
| 13 | |
| 14 | #ifndef BASE_CALLBACK_HELPERS_H_ |
| 15 | #define BASE_CALLBACK_HELPERS_H_ |
| 16 | |
avi@chromium.org | b74bab8 | 2013-08-30 11:04:04 +0900 | [diff] [blame] | 17 | #include "base/basictypes.h" |
fischman@chromium.org | dc221a7 | 2012-03-25 05:37:27 +0900 | [diff] [blame] | 18 | #include "base/callback.h" |
avi@chromium.org | b74bab8 | 2013-08-30 11:04:04 +0900 | [diff] [blame] | 19 | #include "base/compiler_specific.h" |
fischman@chromium.org | dc221a7 | 2012-03-25 05:37:27 +0900 | [diff] [blame] | 20 | |
| 21 | namespace base { |
| 22 | |
| 23 | template <typename Sig> |
| 24 | base::Callback<Sig> ResetAndReturn(base::Callback<Sig>* cb) { |
| 25 | base::Callback<Sig> ret(*cb); |
| 26 | cb->Reset(); |
| 27 | return ret; |
| 28 | } |
| 29 | |
avi@chromium.org | b74bab8 | 2013-08-30 11:04:04 +0900 | [diff] [blame] | 30 | // ScopedClosureRunner is akin to scoped_ptr for Closures. It ensures that the |
| 31 | // Closure is executed and deleted no matter how the current scope exits. |
| 32 | class BASE_EXPORT ScopedClosureRunner { |
| 33 | public: |
| 34 | ScopedClosureRunner(); |
| 35 | explicit ScopedClosureRunner(const Closure& closure); |
| 36 | ~ScopedClosureRunner(); |
| 37 | |
| 38 | void Reset(); |
| 39 | void Reset(const Closure& closure); |
| 40 | Closure Release() WARN_UNUSED_RESULT; |
| 41 | |
| 42 | private: |
| 43 | Closure closure_; |
| 44 | |
| 45 | DISALLOW_COPY_AND_ASSIGN(ScopedClosureRunner); |
| 46 | }; |
| 47 | |
fischman@chromium.org | dc221a7 | 2012-03-25 05:37:27 +0900 | [diff] [blame] | 48 | } // namespace base |
| 49 | |
| 50 | #endif // BASE_CALLBACK_HELPERS_H_ |