Set a minHeight and a minWidth for the main window

[waterflow80]

Is your suggestion for improvement related to a problem? Please describe.
The JabRef main window has no minimum width or height. So you can decrease the
size until it can be no longer seen. Which I think is not a good thing.
(See 'Window before change' in the Additional context below ↓)

Describe the solution you'd like
I simply suggest to add a setMinHeight and a setMinWidth in the openWindow() method under
JabRefGui class.

I have chosen the values of minWidth and minHeight as follows:

• minWidth:

  • 
  • I've chosen the width in a way that the up menu bar keeps displaying all its
    content (File, Edit, ...) after resize (after decreasing the size).
  • It's about 580px (Using Ubuntu 20.04).

• minHeight:

  • 
  • I've chosen the height in a way that the element OpenOffice/LibreOffice is shown entirely after resize (after decreasing the size).
    I chosen OpenOffice/LibreOffice as a reference, because I found that it has the highest height among other elements under
    the view option menu (compared to Web search and Groups).

• It's about 330px (Using Ubuntu 20.04).

Additional context

• Window before change
  

• Minimum window size after change
  

Other
Looking forward to hear your feedback, and to make a PR on this.

[Siedlerchr]

Thanks. Seems like a good idea!. Btw as you also are using Ubuntu, can you reproduce #9607 ?

[waterflow80]

@Siedlerchr Yeah sure, I'll give it a try.

[koppor]

We discussed in the DevCall. The feature improves the state of the art and thus we take it.

We accept that JabRef will have issues with tiling window managers at small screen resolutions. We hope that we will find the point in the code as soon as a user of dwm or similar tools will raise their voice.