Qt 5.11 | Qt Widgets | Move Blocks Example | main.cpp Example File

Qt 5.11.3 Reference Documentation

# main.cpp Example File

animation/moveblocks/main.cpp

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      #include <QtCore>
      #include <QtWidgets>

      class StateSwitchEvent: public QEvent
      {
      public:
          StateSwitchEvent()
              : QEvent(Type(StateSwitchType))
          {
          }

          explicit StateSwitchEvent(int rand)
              : QEvent(Type(StateSwitchType)),
                m_rand(rand)
          {
          }

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

          int rand() const { return m_rand; }

      private:
          int m_rand;
      };

      class QGraphicsRectWidget : public QGraphicsWidget
      {
      public:
          void paint(QPainter *painter, const QStyleOptionGraphicsItem *,
                     QWidget *) override
          {
              painter->fillRect(rect(), Qt::blue);
          }
      };

      class StateSwitchTransition: public QAbstractTransition
      {
      public:
          StateSwitchTransition(int rand)
              : QAbstractTransition(),
                m_rand(rand)
          {
          }

      protected:
          bool eventTest(QEvent *event) override
          {
              return (event->type() == QEvent::Type(StateSwitchEvent::StateSwitchType))
                  && (static_cast<StateSwitchEvent *>(event)->rand() == m_rand);
          }

          void onTransition(QEvent *) override {}

      private:
          int m_rand;
      };

      class StateSwitcher : public QState
      {
          Q_OBJECT
      public:
          StateSwitcher(QStateMachine *machine)
              : QState(machine), m_stateCount(0), m_lastIndex(0)
          { }

          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 {}

          void addState(QState *state, QAbstractAnimation *animation) {
              StateSwitchTransition *trans = new StateSwitchTransition(++m_stateCount);
              trans->setTargetState(state);
              addTransition(trans);
              trans->addAnimation(animation);
          }

      private:
          int m_stateCount;
          int m_lastIndex;
      };

      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;
      }

      class GraphicsView : public QGraphicsView
      {
          Q_OBJECT
      public:
          GraphicsView(QGraphicsScene *scene, QWidget *parent = NULL) : 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);

          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);
          GraphicsView window(&scene);
          window.setFrameStyle(0);
          window.setAlignment(Qt::AlignLeft | Qt::AlignTop);
          window.setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
          window.setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
          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()));

          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);
          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);
          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);

          QParallelAnimationGroup animationGroup;
          QSequentialAnimationGroup *subGroup;

          QPropertyAnimation *anim = new QPropertyAnimation(button4, "geometry");
          anim->setDuration(1000);
          anim->setEasingCurve(QEasingCurve::OutElastic);
          animationGroup.addAnimation(anim);

          subGroup = new QSequentialAnimationGroup(&animationGroup);
          subGroup->addPause(100);
          anim = new QPropertyAnimation(button3, "geometry");
          anim->setDuration(1000);
          anim->setEasingCurve(QEasingCurve::OutElastic);
          subGroup->addAnimation(anim);

          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);

          StateSwitcher *stateSwitcher = new StateSwitcher(&machine);
          stateSwitcher->setObjectName("stateSwitcher");
          group->addTransition(&timer, SIGNAL(timeout()), stateSwitcher);
          stateSwitcher->addState(state1, &animationGroup);
          stateSwitcher->addState(state2, &animationGroup);
          stateSwitcher->addState(state3, &animationGroup);
          stateSwitcher->addState(state4, &animationGroup);
          stateSwitcher->addState(state5, &animationGroup);
          stateSwitcher->addState(state6, &animationGroup);
          stateSwitcher->addState(state7, &animationGroup);

          machine.addState(group);
          machine.setInitialState(group);
          machine.start();

          window.resize(300, 300);
          window.show();

          return app.exec();
      }

      #include "main.moc"