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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include <QtCore/QEvent>
#include <QtCore/QParallelAnimationGroup>
#include <QtCore/QPropertyAnimation>
#include <QtCore/QRandomGenerator>
#include <QtCore/QSequentialAnimationGroup>
#include <QtCore/QTimer>
#include <QtGui/QPainter>
#include <QtStateMachine/QAbstractTransition>
#include <QtStateMachine/QState>
#include <QtStateMachine/QStateMachine>
#include <QtWidgets/QApplication>
#include <QtWidgets/QGraphicsView>
#include <QtWidgets/QGraphicsWidget>
//![15]
class StateSwitchEvent: public QEvent
{
public:
explicit StateSwitchEvent(int rand) : QEvent(StateSwitchType), m_rand(rand) { }
static constexpr QEvent::Type StateSwitchType = QEvent::Type(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 *) override
{
painter->fillRect(rect(), Qt::blue);
}
};
//![16]
class StateSwitchTransition: public QAbstractTransition
{
public:
explicit StateSwitchTransition(int rand) : QAbstractTransition(), m_rand(rand) { }
protected:
//![14]
bool eventTest(QEvent *event) override
{
return (event->type() == QEvent::Type(StateSwitchEvent::StateSwitchType))
&& (static_cast<StateSwitchEvent *>(event)->rand() == m_rand);
}
//![14]
void onTransition(QEvent *) override {}
private:
int m_rand;
};
//![10]
class StateSwitcher : public QState
{
Q_OBJECT
public:
explicit StateSwitcher(QStateMachine *machine) : QState(machine) { }
//![10]
//![11]
void onEntry(QEvent *) override
{
int n;
while ((n = QRandomGenerator::global()->bounded(m_stateCount) + 1) == m_lastIndex)
{ }
m_lastIndex = n;
machine()->postEvent(new StateSwitchEvent(n));
}
void onExit(QEvent *) override {}
//![11]
//![12]
void addState(QState *state, QAbstractAnimation *animation) {
auto trans = new StateSwitchTransition(++m_stateCount);
trans->setTargetState(state);
addTransition(trans);
trans->addAnimation(animation);
}
//![12]
private:
int m_stateCount = 0;
int m_lastIndex = 0;
};
//![13]
static QState *createGeometryState(QObject *w1, const QRect &rect1, QObject *w2, const QRect &rect2,
QObject *w3, const QRect &rect3, QObject *w4, const QRect &rect4,
QState *parent)
{
auto 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]
class GraphicsView : public QGraphicsView
{
Q_OBJECT
public:
explicit GraphicsView(QGraphicsScene *scene, QWidget *parent = nullptr)
: QGraphicsView(scene, parent)
{
}
protected:
void resizeEvent(QResizeEvent *event) override
{
fitInView(scene()->sceneRect());
QGraphicsView::resizeEvent(event);
}
};
int main(int argc, char **argv)
{
QApplication app(argc, argv);
//![1]
auto button1 = new QGraphicsRectWidget;
auto button2 = new QGraphicsRectWidget;
auto button3 = new QGraphicsRectWidget;
auto 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]
GraphicsView window(&scene);
window.setFrameStyle(0);
window.setAlignment(Qt::AlignLeft | Qt::AlignTop);
window.setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
window.setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
//![2]
QStateMachine machine;
auto group = new QState;
group->setObjectName("group");
QTimer timer;
timer.setInterval(1250);
timer.setSingleShot(true);
QObject::connect(group, &QState::entered, &timer, QOverload<>::of(&QTimer::start));
//![2]
//![3]
auto 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]
auto 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);
auto 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);
auto 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);
auto 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);
auto 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]
auto 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;
auto anim = new QPropertyAnimation(button4, "geometry");
anim->setDuration(1000);
anim->setEasingCurve(QEasingCurve::OutElastic);
animationGroup.addAnimation(anim);
//![5]
//![6]
auto 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]
auto stateSwitcher = new StateSwitcher(&machine);
stateSwitcher->setObjectName("stateSwitcher");
group->addTransition(&timer, &QTimer::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();
return app.exec();
}
#include "main.moc"
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