#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>
#include <QtCore>
#include <QtGui>

namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
    Q_OBJECT

public:
    explicit Dialog(QWidget *parent = 0);
    ~Dialog();

private slots:
    void on_pushButton_2_clicked();

    void on_pushButton_clicked();

private:
    Ui::Dialog *ui;
    QGraphicsScene *escena;
    QGraphicsEllipseItem *elipse;
    QGraphicsRectItem *rectangulo;

};

#endif // DIALOG_H

******************************************************************************************


#include "dialog.h"
#include "ui_dialog.h"

Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);
    escena = new QGraphicsScene(this);
    ui->graphicsView->setScene(escena);

    QBrush redBrush(Qt::red);
    QBrush blueBrush(Qt::blue);
    QPen blackpen(Qt::black);

    elipse = escena->addEllipse(10,10,100,100,blackpen,redBrush);
    elipse->setFlag(QGraphicsItem::ItemIsMovable);
    rectangulo = escena->addRect(-100,-100,50,50,blackpen,blueBrush);
    rectangulo->setFlag(QGraphicsItem::ItemIsMovable);

}

Dialog::~Dialog()
{
    delete ui;
}

void Dialog::on_pushButton_2_clicked()
{
    ui->graphicsView->rotate(15);
}

void Dialog::on_pushButton_clicked()
{
    ui->graphicsView->rotate(-15);
}