eventqueue.h

/*
 * Orca-Robotics Project: Components for robotics 
 *               http://orca-robotics.sf.net/
 * Copyright (c) 2004-2009 Alex Brooks, Alexei Makarenko, Tobias Kaupp
 *
 * This distribution is licensed to you under the terms described in
 * the LICENSE file included in this distribution.
 *
 */

#ifndef HYDROICEUTIL_EVENT_QUEUE_H
#define HYDROICEUTIL_EVENT_QUEUE_H

#include <list>
#include <IceUtil/Monitor.h>
#include <IceUtil/Mutex.h>
#include <IceUtil/Handle.h>
#include <IceUtil/Shared.h>
#include <hydroiceutil/event.h>

namespace hydroiceutil
{

class EventQueueOptimizer : public IceUtil::Shared
{
public:
    virtual bool combine( EventPtr& existing, const EventPtr& extra ) { return false; };
};

typedef IceUtil::Handle<EventQueueOptimizer> EventQueueOptimizerPtr;

class EventQueue : public IceUtil::Shared, public IceUtil::Monitor<IceUtil::Mutex>
{
public:
    EventQueue( bool traceAddEvents=false, bool traceGetEvents=false );

    void setOptimizer( EventQueueOptimizerPtr optimizer );

    void add( const EventPtr& e );

    void add( int type );

    void optimizedAdd( const EventPtr& e );

    void get( EventPtr& e );

    bool timedGet( EventPtr& e, int timeoutMs );

    void clear();

    int size() const;

private:
    std::list<EventPtr> events_;
    EventQueueOptimizerPtr optimizer_;
    bool traceAddEvents_;
    bool traceGetEvents_;
};
typedef IceUtil::Handle<EventQueue> EventQueuePtr;

class EventQueueHolder : public IceUtil::Shared
{
public:
    virtual ~EventQueueHolder() {};
    virtual void postEvent( const EventPtr& e )=0;

    // implementation note:
    // I'd prefer to make this function polymorphic, postEvent(int), but ...
    // it will be hidden by the derived class's implementation of postEvent(const EventPtr&)
    // see http://www.parashift.com/c++-faq-lite/strange-inheritance.html#faq-23.9
    // It could be "unhidden" with 'using' in the derived class, but this is super ugly.
    //      using hydroiceutil::EventQueueHolder::postEvent;
    virtual void postEventWithType( int type ) { postEvent( new hydroiceutil::Event(type) ); };
};
typedef IceUtil::Handle<EventQueueHolder> EventQueueHolderPtr;

} // namespace

#endif