blob: 6a3c2ef7402bdf9203ef350dcff740f806d1210d [file] [log] [blame]
/*
* Copyright 2004 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.
*/
#ifndef WEBRTC_BASE_MESSAGEHANDLER_H_
#define WEBRTC_BASE_MESSAGEHANDLER_H_
#include <memory>
#include <utility>
#include "webrtc/base/constructormagic.h"
namespace rtc {
struct Message;
// Messages get dispatched to a MessageHandler
class MessageHandler {
public:
virtual ~MessageHandler();
virtual void OnMessage(Message* msg) = 0;
protected:
MessageHandler() {}
private:
RTC_DISALLOW_COPY_AND_ASSIGN(MessageHandler);
};
// Helper class to facilitate executing a functor on a thread.
template <class ReturnT, class FunctorT>
class FunctorMessageHandler : public MessageHandler {
public:
explicit FunctorMessageHandler(const FunctorT& functor)
: functor_(functor) {}
virtual void OnMessage(Message* msg) {
result_ = functor_();
}
const ReturnT& result() const { return result_; }
private:
FunctorT functor_;
ReturnT result_;
};
// Specialization for std::unique_ptr<ReturnT>.
template <class ReturnT, class FunctorT>
class FunctorMessageHandler<class std::unique_ptr<ReturnT>, FunctorT>
: public MessageHandler {
public:
explicit FunctorMessageHandler(const FunctorT& functor) : functor_(functor) {}
virtual void OnMessage(Message* msg) { result_ = std::move(functor_()); }
std::unique_ptr<ReturnT> result() { return std::move(result_); }
private:
FunctorT functor_;
std::unique_ptr<ReturnT> result_;
};
// Specialization for ReturnT of void.
template <class FunctorT>
class FunctorMessageHandler<void, FunctorT> : public MessageHandler {
public:
explicit FunctorMessageHandler(const FunctorT& functor)
: functor_(functor) {}
virtual void OnMessage(Message* msg) {
functor_();
}
void result() const {}
private:
FunctorT functor_;
};
} // namespace rtc
#endif // WEBRTC_BASE_MESSAGEHANDLER_H_