C++ (Qt)
void MyItem::keyPressEvent(QKeyEvent *event)
{
   auto key = event->key();
   if (key == Qt::Key_Up && speed<maxSpeed)
        if (speed < 0)  speed += dec;
        else  speed += acc;
 
    if (key == Qt::Key_Down && speed>-maxSpeed)
        if (speed > 0) speed -= dec;
        else  speed -= acc;
 
    if (key != Qt::Key_Up && key != Qt::Key_Down)
        if (speed - dec > 0) speed -= dec;
        else if (speed + dec < 0) speed += dec;
        else speed = 0;
 
    if (key == Qt::Key_Right && speed!=0)  angle += turnSpeed * speed/maxSpeed;
    if (key == Qt::Key_Left && speed!=0)   angle -= turnSpeed * speed/maxSpeed;
 
    car[0].speed = speed;
    car[0].angle = angle;
}