1  MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
2  {
3    ui->setupUi(this);
4    scene = new QGraphicsScene(this);
5    ui->graphicsView->setScene(scene);
6    QBrush redBrush(Qt::red);
7    QBrush blueBrush(Qt::blue);
8    QPen blackpen(Qt::black);
9    blackpen.setWidth(5);
10   ellipse = scene->addEllipse(10, 10, 160, 100, blackpen, blueBrush);
11   rectangle = scene->addRect(-100, -100, 50, 50, blackpen, redBrush);
12   rectangle->setFlag(QGraphicsItem::ItemIsMovable);
13   ellipse->setFlag(QGraphicsItem::ItemIsMovable);
14 }