Qt Reference Documentation

# main.cpp Example File

statemachine/eventtransitions/main.cpp

     /****************************************************************************
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     ** All rights reserved.
     ** Contact: Nokia Corporation (qt-info@nokia.com)
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     ** This file is part of the QtCore module of the Qt Toolkit.
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     ** You may use this file under the terms of the BSD license as follows:
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     #include <QtGui>

     class Window : public QWidget
     {
     public:
         Window(QWidget *parent = 0)
             : QWidget(parent)
         {
             QPushButton *button = new QPushButton(this);
             button->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);

             QVBoxLayout *layout = new QVBoxLayout;
             layout->addWidget(button);
             layout->setContentsMargins(80, 80, 80, 80);
             setLayout(layout);

             QStateMachine *machine = new QStateMachine(this);

             QState *s1 = new QState();
             s1->assignProperty(button, "text", "Outside");

             QState *s2 = new QState();
             s2->assignProperty(button, "text", "Inside");

             QEventTransition *enterTransition = new QEventTransition(button, QEvent::Enter);
             enterTransition->setTargetState(s2);
             s1->addTransition(enterTransition);

             QEventTransition *leaveTransition = new QEventTransition(button, QEvent::Leave);
             leaveTransition->setTargetState(s1);
             s2->addTransition(leaveTransition);

             QState *s3 = new QState();
             s3->assignProperty(button, "text", "Pressing...");

             QEventTransition *pressTransition = new QEventTransition(button, QEvent::MouseButtonPress);
             pressTransition->setTargetState(s3);
             s2->addTransition(pressTransition);

             QEventTransition *releaseTransition = new QEventTransition(button, QEvent::MouseButtonRelease);
             releaseTransition->setTargetState(s2);
             s3->addTransition(releaseTransition);

             machine->addState(s1);
             machine->addState(s2);
             machine->addState(s3);

             machine->setInitialState(s1);
             machine->start();
         }
     };

     int main(int argc, char **argv)
     {
         QApplication app(argc, argv);
         Window window;
         window.resize(300, 300);
     #if defined(Q_OS_SYMBIAN)
         window.showMaximized();
     #else
         window.show();
     #endif

         return app.exec();
     }