qt - QRubberBand on a definite label -

strange things happening: need use rubberband on label. here's code:

    qrubberband *rubberband;     qpoint mypoint;  void mainwindow::mousepressevent(qmouseevent *event){      mypoint = event->pos();     rubberband = new qrubberband(qrubberband::rectangle, ui->label_2);//new rectangle band     rubberband->setgeometry(qrect(mypoint, ui->label_2->size()));     rubberband->show(); }  void mainwindow::mousemoveevent(qmouseevent *event){     rubberband->setgeometry(qrect(mypoint, event->pos()).normalized());//area bounding }  void mainwindow::mousereleaseevent(qmouseevent *event){     rubberband->hide();// hide on mouse release     rubberband->clearmask(); } 

everything works there's 1 trouble - rubberbound starts paint little bit lower coursor set around 100-150px.

what doing wrong ?

the event->pos() in different coordinate system of label, , rubberband.

http://qt-project.org/doc/qt-4.8/qwidget.html#mapfrom

http://qt-project.org/doc/qt-4.8/qwidget.html#mapfromglobal

http://qt-project.org/doc/qt-4.8/qwidget.html#mapfromglobal

http://qt-project.org/doc/qt-4.8/application-windows.html

http://qt-project.org/doc/qt-4.8/qwidget.html#geometry-prop

http://qt-project.org/doc/qt-4.8/qwidget.html#rect-prop

you need map event->pos() different coordinate system compensate offset.

edit: here example.

// in constructor set rubberband zero. rubberband = 0;  void mainwindow::mousepressevent(qmouseevent *event){      mypoint = ui->label->mapfromglobal(this->maptoglobal(event->pos()));     // mypoint = ui->label->mapfrom(this, event->pos());     // mypoint = this->mapto(ui->label, event->pos());     if(rubberband == 0) // should add not have memory leak         rubberband = new qrubberband(qrubberband::rectangle, ui->label_2);//new rectangle band     rubberband->setgeometry(qrect(mypoint, ui->label_2->size()));     rubberband->show(); } 

in qrubberband description shows how implemented if being used on widget mouseevents triggered with. since using on different widget widgets mouse events, have map coordinates.

hope helps.