Want to receive event even if not with focus
===

I have a QGraphicsScene inside a QGraphicView.
I want it to receive my keyboard event even if i didn't pressed on the screen.
Because if i click anywhere on the screen with a key held i need to do another action, but now i need to click first, so i need to capture the event even if i'm not with the focus on the QGraphicsScene.
I tried to put the event on the MainWindow, but it dont work.

I get the event like that:

    void AreaScene::keyPressEvent(QKeyEvent *event){
        if(event->key()==Qt::Key_Control){
            MapData::controlPress=true;
        }
    }
    void AreaScene::keyReleaseEvent(QKeyEvent *event){
        if(event->key()==Qt::Key_Control){
                MapData::controlPress=false;
                this->renderArea=false;
        }
    }

Thanks People.