QGraphicsItem Mouse-handling

In my subclassed QGraphicsItem I'd like to draw some points with my mouse. One click with the mouse will result in one point showing up at the screen.When I doubleclick the item will be added to the scene. Is this possible or must the item be added to the scene and then updated? Can anybody help me understand how I can get the mousepressed-event to my Item?

MyScene.cpp

Code:

void MyScene::mousePressEvent(QGraphicsSceneMouseEvent *mouseEvent)
{
    QGraphicsScene::mousePressEvent(mouseEvent);
    QPointF curPos= mouseEvent->lastScenePos();
 
    //Create new item
    if(Mouse.iClicks == 0)
    {
        qDebug("Creating new spline.");
        newSpline = new itemSpline();
    }
 
    newSpline->setVertices(curPos);
 
    Mouse.iClicks++;
}
 
void MyScene::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *mouseEvent)
{
    //TODO: Remove last point because dblclick takes one position.
 
    qDebug("MyScene: DoubleClickEvent");
    if(newSpline->size() > 1)
    {
        qDebug("Adding item");
        this->addItem(newSpline);
        this->addRect(newSpline->boundingRect());
    }
    Mouse.iClicks = 0;
}

MyItem.cpp

Code:

void item::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    painter->setRenderHint(QPainter::Antialiasing);
    painter->setBrush(Qt::lightGray);
    //Draw line.
}
 
void item::hoverEnterEvent(QGraphicsSceneHoverEvent* event)
{
    //Catch mouse pos.
    QMessageBox m;
    m.setText("Test");
    m.exec();
}
 
void item::mousePressEvent(QGraphicsSceneMouseEvent* event)
{
    QMessageBox m;
    m.setText("Test");
    m.exec();
}
 
void item::mouseMoveEvent(QGraphicsSceneEvent *event)
{
    //Draw line from start pos to current pos.
}