/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtCore module of the Qt Toolkit.

**

**

**

** $QT_END_LICENSE$

**

****************************************************************************/

#include <QtCore>

#include <QtGui>

//![15]

class StateSwitchEvent: public QEvent

{

public:

    StateSwitchEvent()

        : QEvent(Type(StateSwitchType))

    {

    }

    StateSwitchEvent(int rand)

        : QEvent(Type(StateSwitchType)),

          m_rand(rand)

    {

    }

    enum { StateSwitchType = QEvent::User + 256 };

    int rand() const { return m_rand; }

private:

    int m_rand;

};

//![15]

//![16]

class QGraphicsRectWidget : public QGraphicsWidget

{

public:

    void paint(QPainter *painter, const QStyleOptionGraphicsItem *,

               QWidget *)

    {

        painter->fillRect(rect(), Qt::blue);

    }

};

//![16]

class StateSwitchTransition: public QAbstractTransition

{

public:

    StateSwitchTransition(int rand)

        : QAbstractTransition(),

          m_rand(rand)

    {

    }

protected:

//![14]

    virtual bool eventTest(QEvent *event)

    {

        return (event->type() == QEvent::Type(StateSwitchEvent::StateSwitchType))

            && (static_cast<StateSwitchEvent *>(event)->rand() == m_rand);

    }

//![14]

    virtual void onTransition(QEvent *) {}

private:

    int m_rand;

};

//![10]

class StateSwitcher : public QState

{

    Q_OBJECT

public:

    StateSwitcher(QStateMachine *machine)

        : QState(machine), m_stateCount(0), m_lastIndex(0)

    { }

//![10]

//![11]

    virtual void onEntry(QEvent *)

    {

        int n;

        while ((n = (qrand() % m_stateCount + 1)) == m_lastIndex)

        { }

        m_lastIndex = n;

        machine()->postEvent(new StateSwitchEvent(n));

    }

    virtual void onExit(QEvent *) {}

//![11]

//![12]

    void addState(QState *state, QAbstractAnimation *animation) {

        StateSwitchTransition *trans = new StateSwitchTransition(++m_stateCount);

        trans->setTargetState(state);

        addTransition(trans);

        trans->addAnimation(animation);

    }

//![12]

private:

    int m_stateCount;

    int m_lastIndex;

};

//![13]

QState *createGeometryState(QObject *w1, const QRect &rect1,

                            QObject *w2, const QRect &rect2,

                            QObject *w3, const QRect &rect3,

                            QObject *w4, const QRect &rect4,

                            QState *parent)

{

    QState *result = new QState(parent);

    result->assignProperty(w1, "geometry", rect1);

    result->assignProperty(w2, "geometry", rect2);

    result->assignProperty(w3, "geometry", rect3);

    result->assignProperty(w4, "geometry", rect4);

    return result;

}

//![13]

int main(int argc, char **argv)

{

    QApplication app(argc, argv);

#if 0

    QWidget window;

    QPalette palette;

    palette.setBrush(QPalette::Window, Qt::black);

    window.setPalette(palette);

    QPushButton *button1 = new QPushButton("A", &window);

    QPushButton *button2 = new QPushButton("B", &window);

    QPushButton *button3 = new QPushButton("C", &window);

    QPushButton *button4 = new QPushButton("D", &window);

    button1->setObjectName("button1");

    button2->setObjectName("button2");

    button3->setObjectName("button3");

    button4->setObjectName("button4");

#else

//![1]

    QGraphicsRectWidget *button1 = new QGraphicsRectWidget;

    QGraphicsRectWidget *button2 = new QGraphicsRectWidget;

    QGraphicsRectWidget *button3 = new QGraphicsRectWidget;

    QGraphicsRectWidget *button4 = new QGraphicsRectWidget;

    button2->setZValue(1);

    button3->setZValue(2);

    button4->setZValue(3);

    QGraphicsScene scene(0, 0, 300, 300);

    scene.setBackgroundBrush(Qt::black);

    scene.addItem(button1);

    scene.addItem(button2);

    scene.addItem(button3);

    scene.addItem(button4);

//![1]

    QGraphicsView window(&scene);

    window.setFrameStyle(0);

    window.setAlignment(Qt::AlignLeft | Qt::AlignTop);

    window.setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

    window.setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

#endif

//![2]

    QStateMachine machine;

    QState *group = new QState();

    group->setObjectName("group");

    QTimer timer;

    timer.setInterval(1250);

    timer.setSingleShot(true);

    QObject::connect(group, SIGNAL(entered()), &timer, SLOT(start()));

//![2]

//![3]

    QState *state1;

    QState *state2;

    QState *state3;

    QState *state4;

    QState *state5;

    QState *state6;

    QState *state7;

    state1 = createGeometryState(button1, QRect(100, 0, 50, 50),

                                 button2, QRect(150, 0, 50, 50),

                                 button3, QRect(200, 0, 50, 50),

                                 button4, QRect(250, 0, 50, 50),

                                 group);

//![3]

    state2 = createGeometryState(button1, QRect(250, 100, 50, 50),

                                 button2, QRect(250, 150, 50, 50),

                                 button3, QRect(250, 200, 50, 50),

                                 button4, QRect(250, 250, 50, 50),

                                 group);

    state3 = createGeometryState(button1, QRect(150, 250, 50, 50),

                                 button2, QRect(100, 250, 50, 50),

                                 button3, QRect(50, 250, 50, 50),

                                 button4, QRect(0, 250, 50, 50),

                                 group);

    state4 = createGeometryState(button1, QRect(0, 150, 50, 50),

                                 button2, QRect(0, 100, 50, 50),

                                 button3, QRect(0, 50, 50, 50),

                                 button4, QRect(0, 0, 50, 50),

                                 group);

    state5 = createGeometryState(button1, QRect(100, 100, 50, 50),

                                 button2, QRect(150, 100, 50, 50),

                                 button3, QRect(100, 150, 50, 50),

                                 button4, QRect(150, 150, 50, 50),

                                 group);

    state6 = createGeometryState(button1, QRect(50, 50, 50, 50),

                                 button2, QRect(200, 50, 50, 50),

                                 button3, QRect(50, 200, 50, 50),

                                 button4, QRect(200, 200, 50, 50),

                                 group);

//![4]

    state7 = createGeometryState(button1, QRect(0, 0, 50, 50),

                                 button2, QRect(250, 0, 50, 50),

                                 button3, QRect(0, 250, 50, 50),

                                 button4, QRect(250, 250, 50, 50),

                                 group);

    group->setInitialState(state1);

//![4]

//![5]

    QParallelAnimationGroup animationGroup;

    QSequentialAnimationGroup *subGroup;

    QPropertyAnimation *anim = new QPropertyAnimation(button4, "geometry");

    anim->setDuration(1000);

    anim->setEasingCurve(QEasingCurve::OutElastic);

    animationGroup.addAnimation(anim);

//![5]

//![6]

    subGroup = new QSequentialAnimationGroup(&animationGroup);

    subGroup->addPause(100);

    anim = new QPropertyAnimation(button3, "geometry");

    anim->setDuration(1000);

    anim->setEasingCurve(QEasingCurve::OutElastic);

    subGroup->addAnimation(anim);

//![6]

    subGroup = new QSequentialAnimationGroup(&animationGroup);

    subGroup->addPause(150);

    anim = new QPropertyAnimation(button2, "geometry");

    anim->setDuration(1000);

    anim->setEasingCurve(QEasingCurve::OutElastic);

    subGroup->addAnimation(anim);

    subGroup = new QSequentialAnimationGroup(&animationGroup);

    subGroup->addPause(200);

    anim = new QPropertyAnimation(button1, "geometry");

    anim->setDuration(1000);

    anim->setEasingCurve(QEasingCurve::OutElastic);

    subGroup->addAnimation(anim);

//![7]

    StateSwitcher *stateSwitcher = new StateSwitcher(&machine);

    stateSwitcher->setObjectName("stateSwitcher");

    group->addTransition(&timer, SIGNAL(timeout()), stateSwitcher);

    stateSwitcher->addState(state1, &animationGroup);

    stateSwitcher->addState(state2, &animationGroup);

//![7]

    stateSwitcher->addState(state3, &animationGroup);

    stateSwitcher->addState(state4, &animationGroup);

    stateSwitcher->addState(state5, &animationGroup);

    stateSwitcher->addState(state6, &animationGroup);

//![8]

    stateSwitcher->addState(state7, &animationGroup);

//![8]

//![9]

    machine.addState(group);

    machine.setInitialState(group);

    machine.start();

//![9]

    window.resize(300, 300);

    window.show();

    qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));

    return app.exec();

}

#include "main.moc"