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Diffstat (limited to 'chromium/third_party/webrtc/base/callback.h')
-rw-r--r-- | chromium/third_party/webrtc/base/callback.h | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/chromium/third_party/webrtc/base/callback.h b/chromium/third_party/webrtc/base/callback.h new file mode 100644 index 00000000000..949510e9505 --- /dev/null +++ b/chromium/third_party/webrtc/base/callback.h @@ -0,0 +1,261 @@ +// This file was GENERATED by command: +// pump.py callback.h.pump +// DO NOT EDIT BY HAND!!! + +/* + * Copyright 2012 The WebRTC Project Authors. All rights reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +// To generate callback.h from callback.h.pump, execute: +// /home/build/google3/third_party/gtest/scripts/pump.py callback.h.pump + +// Callbacks are callable object containers. They can hold a function pointer +// or a function object and behave like a value type. Internally, data is +// reference-counted, making copies and pass-by-value inexpensive. +// +// Callbacks are typed using template arguments. The format is: +// CallbackN<ReturnType, ParamType1, ..., ParamTypeN> +// where N is the number of arguments supplied to the callable object. +// Callbacks are invoked using operator(), just like a function or a function +// object. Default-constructed callbacks are "empty," and executing an empty +// callback does nothing. A callback can be made empty by assigning it from +// a default-constructed callback. +// +// Callbacks are similar in purpose to std::function (which isn't available on +// all platforms we support) and a lightweight alternative to sigslots. Since +// they effectively hide the type of the object they call, they're useful in +// breaking dependencies between objects that need to interact with one another. +// Notably, they can hold the results of Bind(), std::bind*, etc, without +// needing +// to know the resulting object type of those calls. +// +// Sigslots, on the other hand, provide a fuller feature set, such as multiple +// subscriptions to a signal, optional thread-safety, and lifetime tracking of +// slots. When these features are needed, choose sigslots. +// +// Example: +// int sqr(int x) { return x * x; } +// struct AddK { +// int k; +// int operator()(int x) const { return x + k; } +// } add_k = {5}; +// +// Callback1<int, int> my_callback; +// cout << my_callback.empty() << endl; // true +// +// my_callback = Callback1<int, int>(&sqr); +// cout << my_callback.empty() << endl; // false +// cout << my_callback(3) << endl; // 9 +// +// my_callback = Callback1<int, int>(add_k); +// cout << my_callback(10) << endl; // 15 +// +// my_callback = Callback1<int, int>(); +// cout << my_callback.empty() << endl; // true + +#ifndef WEBRTC_BASE_CALLBACK_H_ +#define WEBRTC_BASE_CALLBACK_H_ + +#include "webrtc/base/logging.h" +#include "webrtc/base/refcount.h" +#include "webrtc/base/scoped_ref_ptr.h" + +namespace rtc { + +template <class R> +class Callback0 { + public: + // Default copy operations are appropriate for this class. + Callback0() {} + template <class T> Callback0(const T& functor) + : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {} + R operator()() { + if (empty()) + return R(); + return helper_->Run(); + } + bool empty() const { return !helper_; } + + private: + struct Helper : RefCountInterface { + virtual ~Helper() {} + virtual R Run() = 0; + }; + template <class T> struct HelperImpl : Helper { + explicit HelperImpl(const T& functor) : functor_(functor) {} + virtual R Run() { + return functor_(); + } + T functor_; + }; + scoped_refptr<Helper> helper_; +}; + +template <class R, + class P1> +class Callback1 { + public: + // Default copy operations are appropriate for this class. + Callback1() {} + template <class T> Callback1(const T& functor) + : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {} + R operator()(P1 p1) { + if (empty()) + return R(); + return helper_->Run(p1); + } + bool empty() const { return !helper_; } + + private: + struct Helper : RefCountInterface { + virtual ~Helper() {} + virtual R Run(P1 p1) = 0; + }; + template <class T> struct HelperImpl : Helper { + explicit HelperImpl(const T& functor) : functor_(functor) {} + virtual R Run(P1 p1) { + return functor_(p1); + } + T functor_; + }; + scoped_refptr<Helper> helper_; +}; + +template <class R, + class P1, + class P2> +class Callback2 { + public: + // Default copy operations are appropriate for this class. + Callback2() {} + template <class T> Callback2(const T& functor) + : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {} + R operator()(P1 p1, P2 p2) { + if (empty()) + return R(); + return helper_->Run(p1, p2); + } + bool empty() const { return !helper_; } + + private: + struct Helper : RefCountInterface { + virtual ~Helper() {} + virtual R Run(P1 p1, P2 p2) = 0; + }; + template <class T> struct HelperImpl : Helper { + explicit HelperImpl(const T& functor) : functor_(functor) {} + virtual R Run(P1 p1, P2 p2) { + return functor_(p1, p2); + } + T functor_; + }; + scoped_refptr<Helper> helper_; +}; + +template <class R, + class P1, + class P2, + class P3> +class Callback3 { + public: + // Default copy operations are appropriate for this class. + Callback3() {} + template <class T> Callback3(const T& functor) + : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {} + R operator()(P1 p1, P2 p2, P3 p3) { + if (empty()) + return R(); + return helper_->Run(p1, p2, p3); + } + bool empty() const { return !helper_; } + + private: + struct Helper : RefCountInterface { + virtual ~Helper() {} + virtual R Run(P1 p1, P2 p2, P3 p3) = 0; + }; + template <class T> struct HelperImpl : Helper { + explicit HelperImpl(const T& functor) : functor_(functor) {} + virtual R Run(P1 p1, P2 p2, P3 p3) { + return functor_(p1, p2, p3); + } + T functor_; + }; + scoped_refptr<Helper> helper_; +}; + +template <class R, + class P1, + class P2, + class P3, + class P4> +class Callback4 { + public: + // Default copy operations are appropriate for this class. + Callback4() {} + template <class T> Callback4(const T& functor) + : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {} + R operator()(P1 p1, P2 p2, P3 p3, P4 p4) { + if (empty()) + return R(); + return helper_->Run(p1, p2, p3, p4); + } + bool empty() const { return !helper_; } + + private: + struct Helper : RefCountInterface { + virtual ~Helper() {} + virtual R Run(P1 p1, P2 p2, P3 p3, P4 p4) = 0; + }; + template <class T> struct HelperImpl : Helper { + explicit HelperImpl(const T& functor) : functor_(functor) {} + virtual R Run(P1 p1, P2 p2, P3 p3, P4 p4) { + return functor_(p1, p2, p3, p4); + } + T functor_; + }; + scoped_refptr<Helper> helper_; +}; + +template <class R, + class P1, + class P2, + class P3, + class P4, + class P5> +class Callback5 { + public: + // Default copy operations are appropriate for this class. + Callback5() {} + template <class T> Callback5(const T& functor) + : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {} + R operator()(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5) { + if (empty()) + return R(); + return helper_->Run(p1, p2, p3, p4, p5); + } + bool empty() const { return !helper_; } + + private: + struct Helper : RefCountInterface { + virtual ~Helper() {} + virtual R Run(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5) = 0; + }; + template <class T> struct HelperImpl : Helper { + explicit HelperImpl(const T& functor) : functor_(functor) {} + virtual R Run(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5) { + return functor_(p1, p2, p3, p4, p5); + } + T functor_; + }; + scoped_refptr<Helper> helper_; +}; +} // namespace rtc + +#endif // WEBRTC_BASE_CALLBACK_H_ |