Qt 4.8: lifecycle.cpp Example File (animation/stickman/lifecycle.cpp)

Qt Reference Documentation

# lifecycle.cpp Example File

animation/stickman/lifecycle.cpp

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     #include "lifecycle.h"
     #include "stickman.h"
     #include "node.h"
     #include "animation.h"
     #include "graphicsview.h"

     #include <QtCore>
     #include <QtGui>

     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)
         {
             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)
         {
             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", Qt::white);
         lightningBlink->assignProperty(m_stickMan, "penColor", Qt::black);
         lightningBlink->assignProperty(m_stickMan, "fillColor", 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", Qt::black);
         m_dead->assignProperty(m_stickMan, "penColor", Qt::white);
         m_dead->assignProperty(m_stickMan, "fillColor", 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;
     }