Qt Reference Documentation

# main.cpp Example File

statemachine/pingpong/main.cpp

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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();
     }