[Development] Updated high-DPI support for Qt 5.14

[Shawn Rutledge]

On Sep 26, 2019, at 9:08, Allan Sandfeld Jensen <kde at carewolf.com> wrote:

> On Thursday, 26 September 2019 04:48:26 CEST Thiago Macieira wrote:
>>> If possible, I’d like us to move away from relying on setting environment
>>> variables, and/or switch to specifying per-screen DPI instead of a scale
>>> factor.
>> 
>> Sure, but where, on X11?
> 
> xrandr?
> 
> We read the X11 setting there. Though if you use GNOME they will override the 
> values to something meaningless, and we don't currently read the GNOME per 
> screen settings. For KDE it should work though.

Can you be more specific?  Which values become meaningless, and what sort of values are we talking about?

Which ones does KDE get right?

KDE also needs to set env variables to get correct behavior, right?  Which ones does it do right?  Which ones are wrong or unnecessary in 5.14?

Ultimately my goals are 1) figure out how to configure a plain X11/openbox session to get what I want (arbitrary scaling on each display) 2) figure out how to do it in a wayland compositor (which should probably be done in the same way that KDE does or should do it).