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/*
* Copyright (c) 2003 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __CALLBACK_HH__
#define __CALLBACK_HH__
#include <list>
/**
* Generic callback class. This base class provides a virtual process
* function that gets called when the callback queue is processed.
*/
class Callback
{
public:
/**
* virtualize the destructor to make sure that the correct one
* gets called.
*/
virtual ~Callback() {}
/**
* virtual process function that is invoked when the callback
* queue is executed.
*/
virtual void process() = 0;
};
class CallbackQueue
{
protected:
/**
* Simple typedef for the data structure that stores all of the
* callbacks.
*/
typedef std::list<Callback *> queue;
/**
* List of all callbacks. To be called in fifo order.
*/
queue callbacks;
public:
/**
* Add a callback to the end of the queue
* @param callback the callback to be added to the queue
*/
void add(Callback *callback)
{
callbacks.push_back(callback);
}
/**
* Find out if there are any callbacks in the queue
*/
bool empty() const { return callbacks.empty(); }
/**
* process all callbacks
*/
void process()
{
queue::iterator i = callbacks.begin();
queue::iterator end = callbacks.end();
while (i != end) {
(*i)->process();
++i;
}
}
/**
* clear the callback queue
*/
void clear()
{
callbacks.clear();
}
};
/// Helper template class to turn a simple class member function into
/// a callback.
template <class T, void (T::* F)()>
class MakeCallback : public Callback
{
private:
T *object;
public:
MakeCallback(T *o)
: object(o)
{ }
void process() { (object->*F)(); }
};
#endif // __CALLBACK_HH__
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