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#include <QtGui/QApplication>
#include <QGraphicsView>
#include <QGraphicsScene>
#include <QObject>
#include <QTimer>

#include "stick.h"
#include "mainview.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainView mView;

    QGraphicsScene scene;
    scene.setSceneRect(0, 0, 495, 495);
    scene.setItemIndexMethod(QGraphicsScene::NoIndex);

    Stick *userStick = new Stick;

    userStick->setPos(300, 200);
    scene.addItem(userStick);
    
    mView.setScene(&scene);
    mView.setBackgroundBrush(QPixmap("images/background-space.jpg"));
    mView.setCacheMode(QGraphicsView::CacheBackground);
    mView.setWindowTitle(QT_TRANSLATE_NOOP(QGraphicsView, "Space Bouncing"));
    mView.resize(500, 500);
    mView.show();

    QObject::connect( &mView, SIGNAL(keyPressed(QKeyEvent*)), &scene, SLOT(advance()) );

    return a.exec();
}

#ifndef MAINVIEW_H
#define MAINVIEW_H

#include <QGraphicsView>
#include <QObject>

class MainView : public QGraphicsView
{
    Q_OBJECT

public:
    MainView();

protected:
    // Events
    void keyPressEvent(QKeyEvent *event);

signals:
    void keyPressed(QKeyEvent *event);

};
#endif // MAINVIEW_H

#include <QMessageBox>
#include <QKeyEvent>
#include <QGraphicsItem>
#include "mainview.h"

MainView::MainView()
{}

void MainView::keyPressEvent(QKeyEvent *event) {

    emit keyPressed(event);
}

#ifndef STICK_H
#define STICK_H

#include <QGraphicsItem>
#include <QKeyEvent>

class Stick : public QGraphicsItem
{
public:
    Stick();

    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
    QPainterPath shape() const;
    QRectF boundingRect() const;

protected:
    void advance(int step);
};

#endif // STICK_H

#include <QPainter>
#include <QMessageBox>

#include "stick.h"

Stick::Stick()
{
}

void Stick::paint(QPainter *painter, const QStyleOptionGraphicsItem*, QWidget*) {

    QRect qRect;
    painter->setBrush(Qt::white);

    qRect.setWidth(100);
    qRect.setHeight(30);

    painter->drawRect(qRect);
}

void Stick::advance(int step) {

    if(step==1)
        moveBy(10, 0);
}

// Не понял до конца зачем эта функция...
QPainterPath Stick::shape() const
{
    QPainterPath path;
    path.addEllipse(boundingRect());
    return path;
}

// Не понятно до конца зачем эта функция
QRectF Stick::boundingRect() const
{
    qreal adjust = 0.5;
    return QRectF(-18 - adjust, -22 - adjust,
                  36 + adjust, 60 + adjust);
}