lifecycle.cpp Example File | Qt Widgets 5.12.6

Qt 5.12 | Qt Widgets | Stickman Example | lifecycle.cpp Example File

Qt 5.12.6 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 <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);
          }

          bool eventTest(QEvent *e) 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);
              startTimer(1000);
          }

          bool eventTest(QEvent *e) override
          {
              return QEventTransition::eventTest(e) && QRandomGenerator::global()->bounded(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;
      }