main.cpp Example File

  /****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the QtCore module of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, 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 The Qt Company Ltd 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 *) Q_DECL_OVERRIDE
      {
          machine()->postEvent(new PingEvent());
          fprintf(stdout, "ping?\n");
      }
  };

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

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

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

  protected:
      virtual bool eventTest(QEvent *e) Q_DECL_OVERRIDE {
          return (e->type() == QEvent::User+2);
      }
      virtual void onTransition(QEvent *) Q_DECL_OVERRIDE
      {
          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();
  }