main.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation (qt-info@nokia.com)
 **
 ** This file is part of the QtCore module of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** You may use this file under the terms of the BSD license as follows:
 **
 ** "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 Nokia Corporation and its Subsidiary(-ies) 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."
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include <QtCore>
 #include <stdio.h>

 class PingEvent : public QEvent
 {
 public:
     PingEvent() : QEvent(QEvent::Type(QEvent::User+2))
         {}
 };

 class PongEvent : public QEvent
 {
 public:
     PongEvent() : QEvent(QEvent::Type(QEvent::User+3))
         {}
 };

 class Pinger : public QState
 {
 public:
     Pinger(QState *parent)
         : QState(parent) {}

 protected:
     virtual void onEntry(QEvent *)
     {
         machine()->postEvent(new PingEvent());
         fprintf(stdout, "ping?\n");
     }
 };

 class PongTransition : public QAbstractTransition
 {
 public:
     PongTransition() {}

 protected:
     virtual bool eventTest(QEvent *e) {
         return (e->type() == QEvent::User+3);
     }
     virtual void onTransition(QEvent *)
     {
         machine()->postDelayedEvent(new PingEvent(), 500);
         fprintf(stdout, "ping?\n");
     }
 };

 class PingTransition : public QAbstractTransition
 {
 public:
     PingTransition() {}

 protected:
     virtual bool eventTest(QEvent *e) {
         return (e->type() == QEvent::User+2);
     }
     virtual void onTransition(QEvent *)
     {
         machine()->postDelayedEvent(new PongEvent(), 500);
         fprintf(stdout, "pong!\n");
     }
 };

 int main(int argc, char **argv)
 {
     QCoreApplication app(argc, argv);

     QStateMachine machine;
     QState *group = new QState(QState::ParallelStates);
     group->setObjectName("group");

     Pinger *pinger = new Pinger(group);
     pinger->setObjectName("pinger");
     pinger->addTransition(new PongTransition());

     QState *ponger = new QState(group);
     ponger->setObjectName("ponger");
     ponger->addTransition(new PingTransition());

     machine.addState(group);
     machine.setInitialState(group);
     machine.start();

     return app.exec();
 }