[Development] Problem porting app from Qt4 to Qt5 with multiple X-screen

[Christian Ehrlicher]

Am 09.02.2015 um 15:35 schrieb Friedemann Kleint:
> Hi,
>
>   >we've multiple X-screens configured (:0.0 ... :0.3) but Qt5 seems to
> have lost the ability to display something on another screen than the
> default
>   > QMainWindow *wm = new QMainWindow(dw->screen(1));
>
> Change https://codereview.qt-project.org/#/c/105285/ for
> https://bugreports.qt.io/browse/QTBUG-44070 should improve that.
Thx for the info. I'll check this out tomorrow and report back if my 
issues are all gone :)
>
>   >embedding an application window into another application doesn't work
> correct - the embeded window gets resized with the master but as soon as
> I click somewhere in the master, the >embedded window is hidden by the
> master.
>
> How do you "embed" the window?
In Qt4 I'm using QX11EmbedWidget/EmbedContainer. In Qt5 I use 
QWidget::createWindowContainer() + QWindow::fromWinId(). The simple 
testcase (a QWidget on client and server side) works as expected but I 
my application it does not work. I could not yet figure out which side 
is the problem - on the server site I want to use it as centralWidget() 
of a QMainWindow, on the client side it's a QWidget with custom 
paintings outside the paintevent. I hope to get to this tomorrow evening.

Christian