Rujia Liu <rujia.liu@gmail.com> writes:

> Hi!
>
> I found a strange thing. QGraphicsScene's mousemove event would not be
> triggered if the scene is empty. Actually if I only add a line item,
> mousemove event will not be triggered either. Only after a text is added,
> mousemove event is ok.
>
> It's no big deal because I could add an empty text to get everything work,
> but I'd like to know what's wrong (perhaps I've misunderstood something?)
>
> I can send you relavent codes if you need, but they're too big to post here.

As I replied in a private email, for posterity here:
http://qt-project.org/doc/qt-4.8/qwidget.html#mouseTracking-prop
setMouseTracking need to be set on QGraphicsView.

--
With best regards, Stas.