main.cpp 范例文件

statemachine/trafficlight/main.cpp
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#include <QtWidgets> class LightWidget : public QWidget { Q_OBJECT Q_PROPERTY(bool on READ isOn WRITE setOn) public: LightWidget(const QColor &color, QWidget *parent = 0) : QWidget(parent), m_color(color), m_on(false) {} bool isOn() const { return m_on; } void setOn(bool on) { if (on == m_on) return; m_on = on; update(); } public slots: void turnOff() { setOn(false); } void turnOn() { setOn(true); } protected: void paintEvent(QPaintEvent *) override { if (!m_on) return; QPainter painter(this); painter.setRenderHint(QPainter::Antialiasing); painter.setBrush(m_color); painter.drawEllipse(0, 0, width(), height()); } private: QColor m_color; bool m_on; }; class TrafficLightWidget : public QWidget { public: TrafficLightWidget(QWidget *parent = 0) : QWidget(parent) { QVBoxLayout *vbox = new QVBoxLayout(this); m_red = new LightWidget(Qt::red); vbox->addWidget(m_red); m_yellow = new LightWidget(Qt::yellow); vbox->addWidget(m_yellow); m_green = new LightWidget(Qt::green); vbox->addWidget(m_green); QPalette pal = palette(); pal.setColor(QPalette::Background, Qt::black); setPalette(pal); setAutoFillBackground(true); } LightWidget *redLight() const { return m_red; } LightWidget *yellowLight() const { return m_yellow; } LightWidget *greenLight() const { return m_green; } private: LightWidget *m_red; LightWidget *m_yellow; LightWidget *m_green; }; QState *createLightState(LightWidget *light, int duration, QState *parent = 0) { QState *lightState = new QState(parent); QTimer *timer = new QTimer(lightState); timer->setInterval(duration); timer->setSingleShot(true); QState *timing = new QState(lightState); QObject::connect(timing, SIGNAL(entered()), light, SLOT(turnOn())); QObject::connect(timing, SIGNAL(entered()), timer, SLOT(start())); QObject::connect(timing, SIGNAL(exited()), light, SLOT(turnOff())); QFinalState *done = new QFinalState(lightState); timing->addTransition(timer, SIGNAL(timeout()), done); lightState->setInitialState(timing); return lightState; } class TrafficLight : public QWidget { public: TrafficLight(QWidget *parent = 0) : QWidget(parent) { QVBoxLayout *vbox = new QVBoxLayout(this); TrafficLightWidget *widget = new TrafficLightWidget(); vbox->addWidget(widget); vbox->setMargin(0); QStateMachine *machine = new QStateMachine(this); QState *redGoingYellow = createLightState(widget->redLight(), 3000); redGoingYellow->setObjectName("redGoingYellow"); QState *yellowGoingGreen = createLightState(widget->yellowLight(), 1000); yellowGoingGreen->setObjectName("yellowGoingGreen"); redGoingYellow->addTransition(redGoingYellow, SIGNAL(finished()), yellowGoingGreen); QState *greenGoingYellow = createLightState(widget->greenLight(), 3000); greenGoingYellow->setObjectName("greenGoingYellow"); yellowGoingGreen->addTransition(yellowGoingGreen, SIGNAL(finished()), greenGoingYellow); QState *yellowGoingRed = createLightState(widget->yellowLight(), 1000); yellowGoingRed->setObjectName("yellowGoingRed"); greenGoingYellow->addTransition(greenGoingYellow, SIGNAL(finished()), yellowGoingRed); yellowGoingRed->addTransition(yellowGoingRed, SIGNAL(finished()), redGoingYellow); machine->addState(redGoingYellow); machine->addState(yellowGoingGreen); machine->addState(greenGoingYellow); machine->addState(yellowGoingRed); machine->setInitialState(redGoingYellow); machine->start(); } }; int main(int argc, char **argv) { QApplication app(argc, argv); TrafficLight widget; widget.resize(110, 300); widget.show(); return app.exec(); } #include "main.moc"