[Feature Request] Allow manual setting of default display

[jzetterman]

This is probably something that needs to be facilitated by the compositor, but the visual part of it would be in settings so I am requesting this here, but I can move it to the compositor repo if necessary.

In have one monitor in vertical layout on the left and another which is horizontal on the right. I am guessing that the default display order is based on left to right, however in this case I would prefer my horizontal monitor which is my "main" monitor to be the default.

Current Behavior
Impacts of the current behavior are that games open in the vertical monitor by default and when logging in the vertical has focus, so opening the launcher opens on that monitor which is a minor annoyance.

Workaround
I can run xrandr --output DP-1 --primary to set the horizontal monitor to the default temporarily, but that does not persist through sessions.

Expected behavior
In Cosmic settings I would be able to toggle the default display on each display and have it retain the setting permanently.

I appreciate your consideration and love what you're doing!

[Drakulix]

I guess Xwayland is simply using the first advertised output by default, we certainly don't tell it, which monitor to consider "primary".

In fact COSMIC doesn't really have a concept of a "primary" output, new windows should be spawned on the currently focused one. However games might try to explicitly detect a "primary" display through Xwayland...

So I guess this needs to be a setting for legacy support, given this is something Xwayland supports, but I don't think we want to add this concept in general.

@pop-os/ux This needs designs, if we want to fix it.

[jzetterman]

The interesting thing there then is that my vertically oriented monitor is detected as DP-2 (at least by xrandr) but it's still the default primary monitor.

xrandr --listactivemonitors Monitors: 2 0: +*DP-1 3072/1050x1728/590+1440+832 DP-1 1: +DP-2 1440/700x2560/390+0+0 DP-2