Warning: Calling move() inside moveEvent() can lead to infinite recursion

[babu198649]

hi
i have a qlabel which has to be moved when the mouse receives the mouse move event.

but the documentation warns like this

Warning: Calling move() or setGeometry() inside moveEvent() can lead to infinite recursion.


Then how to achieve movement of a widget

[jpn]

You're interested of QWidget::mouseMoveEvent(), not QWidget::moveEvent(). See http://wiki.qtcentre.org/index.php?title=Moving_widgets for tips.

[babu198649]

thanks
but the t QWidget::mouseMoveEvent does not perform as expected.

here is the code, i dont know what is the bug in it

void IV_label::mouseMoveEvent ( QMouseEvent * event )
{
        //the distance moved by mouse is mapped to top left of widget
	this->move(mapToGlobal(event->pos()) - this->mapToGlobal(this->pos()));
}

void IV_label::mouseMoveEvent ( QMouseEvent * event )
{
        //the distance moved by mouse is mapped to top left of widget
	this->move(mapToGlobal(event->pos()) - this->mapToGlobal(this->pos()));
}

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the widget(label) moves and becomes invisble

i want to move a label using mouse

[jpn]

Well actually, it's you who moves the label widget to a non-sense location. Would you mind taking a look at the wiki article I gave link to?

[babu198649]

i read the article and it works because it takes the reference coordinate of its parents(
else
move(mapToParent(event->pos() - offset));
)

but i have a qscrollarea as my labels parent so i am going for global referencing.

cant we use move function for positioning the child widgets using global reference system.

[babu198649]

oh thanks it works actually there was a mix between the global and parent coordinates.