- Qt 5.5
- Qt Widgets
- Stickman Example
- lifecycle.cpp Example File
- Qt 5.5.1 Reference Documentation

# lifecycle.cpp Example File

animation/stickman/lifecycle.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the QtCore module of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
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    #include "lifecycle.h"
    #include "stickman.h"
    #include "node.h"
    #include "animation.h"
    #include "graphicsview.h"

    #include <QtCore>
    #include <QtWidgets>

    class KeyPressTransition: public QSignalTransition
    {
    public:
        KeyPressTransition(GraphicsView *receiver, Qt::Key key)
            : QSignalTransition(receiver, SIGNAL(keyPressed(int))), m_key(key)
        {
        }
        KeyPressTransition(GraphicsView *receiver, Qt::Key key, QAbstractState *target)
            : QSignalTransition(receiver, SIGNAL(keyPressed(int))), m_key(key)
        {
            setTargetState(target);
        }

        virtual bool eventTest(QEvent *e) Q_DECL_OVERRIDE
        {
            if (QSignalTransition::eventTest(e)) {
                QVariant key = static_cast<QStateMachine::SignalEvent*>(e)->arguments().at(0);
                return (key.toInt() == int(m_key));
            }

            return false;
        }
    private:
        Qt::Key m_key;
    };

    class LightningStrikesTransition: public QEventTransition
    {
    public:
        LightningStrikesTransition(QAbstractState *target)
            : QEventTransition(this, QEvent::Timer)
        {
            setTargetState(target);
            qsrand((uint)QDateTime::currentDateTime().toTime_t());
            startTimer(1000);
        }

        virtual bool eventTest(QEvent *e) Q_DECL_OVERRIDE
        {
            return QEventTransition::eventTest(e) && ((qrand() % 50) == 0);
        }
    };

    LifeCycle::LifeCycle(StickMan *stickMan, GraphicsView *keyReceiver)
        : m_stickMan(stickMan), m_keyReceiver(keyReceiver)
    {
        // Create animation group to be used for all transitions
        m_animationGroup = new QParallelAnimationGroup();
        const int stickManNodeCount = m_stickMan->nodeCount();
        for (int i=0; i<stickManNodeCount; ++i) {
            QPropertyAnimation *pa = new QPropertyAnimation(m_stickMan->node(i), "pos");
            m_animationGroup->addAnimation(pa);
        }

        // Set up initial state graph
        m_machine = new QStateMachine();
        m_machine->addDefaultAnimation(m_animationGroup);

        m_alive = new QState(m_machine);
        m_alive->setObjectName("alive");

        // Make it blink when lightning strikes before entering dead animation
        QState *lightningBlink = new QState(m_machine);
        lightningBlink->assignProperty(m_stickMan->scene(), "backgroundBrush", QColor(Qt::white));
        lightningBlink->assignProperty(m_stickMan, "penColor", QColor(Qt::black));
        lightningBlink->assignProperty(m_stickMan, "fillColor", QColor(Qt::white));
        lightningBlink->assignProperty(m_stickMan, "isDead", true);

        QTimer *timer = new QTimer(lightningBlink);
        timer->setSingleShot(true);
        timer->setInterval(100);
        QObject::connect(lightningBlink, SIGNAL(entered()), timer, SLOT(start()));
        QObject::connect(lightningBlink, SIGNAL(exited()), timer, SLOT(stop()));

        m_dead = new QState(m_machine);
        m_dead->assignProperty(m_stickMan->scene(), "backgroundBrush", QColor(Qt::black));
        m_dead->assignProperty(m_stickMan, "penColor", QColor(Qt::white));
        m_dead->assignProperty(m_stickMan, "fillColor", QColor(Qt::black));
        m_dead->setObjectName("dead");

        // Idle state (sets no properties)
        m_idle = new QState(m_alive);
        m_idle->setObjectName("idle");

        m_alive->setInitialState(m_idle);

        // Lightning strikes at random
        m_alive->addTransition(new LightningStrikesTransition(lightningBlink));
        lightningBlink->addTransition(timer, SIGNAL(timeout()), m_dead);

        m_machine->setInitialState(m_alive);
    }

    void LifeCycle::setDeathAnimation(const QString &fileName)
    {
        QState *deathAnimation = makeState(m_dead, fileName);
        m_dead->setInitialState(deathAnimation);
    }

    void LifeCycle::start()
    {
        m_machine->start();
    }

    void LifeCycle::addActivity(const QString &fileName, Qt::Key key, QObject *sender, const char *signal)
    {
        QState *state = makeState(m_alive, fileName);
        m_alive->addTransition(new KeyPressTransition(m_keyReceiver, key, state));

        if((sender != NULL) || (signal != NULL)) {
            m_alive->addTransition(sender, signal, state);
        }
    }

    QState *LifeCycle::makeState(QState *parentState, const QString &animationFileName)
    {
        QState *topLevel = new QState(parentState);

        Animation animation;
        {
            QFile file(animationFileName);
            if (file.open(QIODevice::ReadOnly))
                animation.load(&file);
        }

        const int frameCount = animation.totalFrames();
        QState *previousState = 0;
        for (int i=0; i<frameCount; ++i) {
            animation.setCurrentFrame(i);

            QState *frameState = new QState(topLevel);
            const int nodeCount = animation.nodeCount();
            for (int j=0; j<nodeCount; ++j)
                frameState->assignProperty(m_stickMan->node(j), "pos", animation.nodePos(j));

            frameState->setObjectName(QString::fromLatin1("frame %0").arg(i));
            if (previousState == 0)
                topLevel->setInitialState(frameState);
            else
                previousState->addTransition(previousState, SIGNAL(propertiesAssigned()), frameState);

            previousState = frameState;
        }

        // Loop
        previousState->addTransition(previousState, SIGNAL(propertiesAssigned()), topLevel->initialState());

        return topLevel;

    }

    LifeCycle::~LifeCycle()
    {
        delete m_machine;
        delete m_animationGroup;
    }