Fix positioning on multiple screens

[guillaumeboehm]

The change to browser.py should fix issues on multiple screens such as in issue #29.

I also added a cursor resize to the Xgreeter which seems reasonable to me, but I guess you can remove it if you think it shouldn't be here.

[JezerM]

Looks nice! I didn't know about QGuiApplication existence and that it's a superclass of QApplication. So, Application.desktop property could be removed to use QGuiApplication methods instead. Also, this could even make possible a multi-monitor support in a future~

[guillaumeboehm]

I'm not sure what you mean by multiple monitor support If it's not what I added in browser.py? So I searched for the use of Application.desktop in the code and couldn't find any, I would be happy to work on this a little bit if it's in my capabilities. Could you detail quickly what you mean ?

[JezerM]

What this PR does is to set the primary window in the primary screen/display, which should fix the #29 issue by setting web-greeter's window in the main monitor. However, this is not a multi-monitor support, as the rest of monitors would still be blank without any window.

By Multi-Monitor support I mean something like JezerM/nody-greeter#11 does, which creates multiple IPC-interconnected windows for each monitor, and allows to set a primary and secondary HTML files whether the monitor is primary or not with a index.yml configuration inside the theme directory.

The Application.desktop property, a QDesktopWidget, was previously used to get the screen properties (like geometry), which is now unused with this PR. Also, the PyQt5 documentation declares most of its methods as deprecated, so I was just saying that this property could be removed~

web-greeter/src/browser/browser.py

Line 118 in 26de61e

desktop: QDesktopWidget

[JezerM]

However, if this PR is just meant to fix the positioning on multiple screens, this should be done~

[guillaumeboehm]

I see! Well that's interesting, I think I'll try to look into multi-monitor support then. Not sure I'll get somewhere but I'll create a PR if I manage something!

[JezerM]

Nice~ Then, this PR will be merged. Thanks!