torpedo.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtCore module of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
 ** and conditions see https://www.qt.io/terms-conditions. For further
 ** information use the contact form at https://www.qt.io/contact-us.
 **
 ** BSD License Usage
 ** Alternatively, you may use this file under the terms of the BSD license
 ** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
 ** met:
 **   * Redistributions of source code must retain the above copyright
 **     notice, this list of conditions and the following disclaimer.
 **   * Redistributions in binary form must reproduce the above copyright
 **     notice, this list of conditions and the following disclaimer in
 **     the documentation and/or other materials provided with the
 **     distribution.
 **   * Neither the name of The Qt Company Ltd nor the names of its
 **     contributors may be used to endorse or promote products derived
 **     from this software without specific prior written permission.
 **
 **
 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 //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();
 }