main.cpp Example File

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 #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();
 }