Qt 5.11 | Qt Widgets | Sub-Attaq | torpedo.cpp Example File

Qt 5.11.3 Reference Documentation

# torpedo.cpp Example File

animation/sub-attaq/torpedo.cpp

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      //Own
      #include "torpedo.h"
      #include "pixmapitem.h"
      #include "boat.h"
      #include "graphicsscene.h"
      #include "animationmanager.h"
      #include "qanimationstate.h"

      #include <QtCore/QPropertyAnimation>
      #include <QtCore/QStateMachine>
      #include <QtCore/QFinalState>

      Torpedo::Torpedo() : PixmapItem(QString::fromLatin1("torpedo"),GraphicsScene::Big),
          currentSpeed(0)
      {
          setZValue(2);
      }

      void Torpedo::launch()
      {
          QPropertyAnimation *launchAnimation = new QPropertyAnimation(this, "pos");
          AnimationManager::self()->registerAnimation(launchAnimation);
          launchAnimation->setEndValue(QPointF(x(),qobject_cast<GraphicsScene *>(scene())->sealLevel() - 15));
          launchAnimation->setEasingCurve(QEasingCurve::InQuad);
          launchAnimation->setDuration(y()/currentSpeed*10);
          connect(launchAnimation,SIGNAL(valueChanged(QVariant)),this,SLOT(onAnimationLaunchValueChanged(QVariant)));
          connect(this,SIGNAL(torpedoExploded()), launchAnimation, SLOT(stop()));

          //We setup the state machine of the torpedo
          QStateMachine *machine = new QStateMachine(this);

          //This state is when the launch animation is playing
          QAnimationState *launched = new QAnimationState(machine);
          launched->setAnimation(launchAnimation);

          //End
          QFinalState *final = new QFinalState(machine);

          machine->setInitialState(launched);

          //### Add a nice animation when the torpedo is destroyed
          launched->addTransition(this, SIGNAL(torpedoExploded()),final);

          //If the animation is finished, then we move to the final state
          launched->addTransition(launched, SIGNAL(animationFinished()), final);

          //The machine has finished to be executed, then the boat is dead
          connect(machine,SIGNAL(finished()),this, SIGNAL(torpedoExecutionFinished()));

          machine->start();
      }

      void Torpedo::setCurrentSpeed(int speed)
      {
          if (speed < 0) {
              qWarning("Torpedo::setCurrentSpeed : The speed is invalid");
              return;
          }
          currentSpeed = speed;
      }

      void Torpedo::onAnimationLaunchValueChanged(const QVariant &)
      {
          foreach (QGraphicsItem *item , collidingItems(Qt::IntersectsItemBoundingRect)) {
              if (Boat *b = qgraphicsitem_cast<Boat*>(item))
                  b->destroy();
          }
      }

      void Torpedo::destroy()
      {
          emit torpedoExploded();
      }