SpaceShip game

Hello,
I got a project to make SpaceShip game.
MainWindow.cc:

Code:

---

// Create scene for the game
    scene_ = std::make_shared<QGraphicsScene>();
 
    // Add player to the galaxy
    //std::shared_ptr<PlayerShip> player = std::make_shared<PlayerShip>(galaxy_);
    PlayerShip *player = new PlayerShip(scene_, galaxy_);
    scene_->addItem(player);
 
    // Add scene to the view
    ui->graphicsView->setScene(scene_.get());

---

Playership.cc:

Code:

---

PlayerShip::PlayerShip(std::shared_ptr<QGraphicsScene> scene, std::shared_ptr<Student::Galaxy> galaxy)
{
    galaxy_ = galaxy;
    scene_ = scene;
}
 
void PlayerShip::keyPressEvent(QKeyEvent *event)
{
    if(event->key() == Qt::Key_Left)
    {
        qDebug() << "Left";
        setPos(x()-10, y());
    }
    else if(event->key() == Qt::Key_Right)
    {
        qDebug() << "Right";
        setPos(x()+10, y());
    }
    else if(event->key() == Qt::Key_Up)
    {
        qDebug() << "Up";
        setPos(x(), y()-10);
    }
    else if(event->key() == Qt::Key_Down)
    {
        qDebug() << "Down";
        setPos(x(), y()+10);
    }
    else if(event->key() == Qt::Key_Space)
    {
        qDebug() << "Space";
        // shoot
    }
 
}

---

I can't figure out how to keep scene - the player in the middle of the scene, I mean, when the player is moving I want to also move the scene, so the game space will be endless. I added scene_ to the PlayerShip class, so e.g. I can set new x/y coordinates after player move, but Im not sure if is it correct way.
Second problem, I don't know, why does not work this code - does not work mean, the player ship will not show:

Code:

---

std::shared_ptr<PlayerShip> player = std::make_shared<PlayerShip>(scene_, galaxy_);
    scene_->addItem(player.get());

---

Thank you for your advice.


Edit:
Well, here is my keyPressEvent function, but Im not sure about the implementation.

Code:

---

void PlayerShip::keyPressEvent(QKeyEvent *event)
{
    if(event->key() == Qt::Key_Left)
    {
        setTransformOriginPoint(QPoint(18,7));
        setRotation(rotation()-5);
    }
    else if(event->key() == Qt::Key_Right)
    {
        setTransformOriginPoint(QPoint(18,7));
        setRotation(rotation()+5);
    }
    else if(event->key() == Qt::Key_Up)
    {   // ToDo: movement is not correct
        qreal diffX = 0, diffY = 0;
        diffX = rect().width()-rect().x();
        diffY = rect().height()-rect().y();
        diffX *= cos( rotation() * PI / 180.0 );
        diffY *= sin( rotation() * PI / 180.0 );
        setPos(x() + diffX, y() + diffY);
        // ToDo: check calculations
        scene_->setSceneRect(scene_->sceneRect().x()+diffX, scene_->sceneRect().y()+diffY, scene_->sceneRect().width(), scene_->sceneRect().height());
    }
    else if(event->key() == Qt::Key_Down)
    {   // ToDo: movement is not correct
        qreal diffX = 0, diffY = 0;
        diffX = rect().width()-rect().x();
        diffY = rect().height()-rect().y();
        diffX *= cos( rotation() * PI / 180.0 );
        diffY *= sin( rotation() * PI / 180.0 );
        setPos(x() - diffX, y() - diffY);
        // ToDo: check calculations
        scene_->setSceneRect(scene_->sceneRect().x()-diffX, scene_->sceneRect().y()-diffY, scene_->sceneRect().width(), scene_->sceneRect().height());
    }
    else if(event->key() == Qt::Key_Space)
    {
        qDebug() << "Space";
        // shoot
    }
}

---