Xfce Forum

JEIhrig

Member

Registered: 2023-04-13

Posts: 1

How can I configure output to be per-output connection instead of per

Hello, new forum member here. Running into a bit of trouble getting the display setup I want and I am hoping someone can point me in the right direction.

I have a laptop with two external displays connected. (So 3 total.)

I want all displays to be forced to HD (Downscaled if needed)

DP-0 and DP-2 to be forced to primary display, and mirror respectively. 
HDMI-0 to be extended desktop to the right.

This is a laptop with the primary display being the built-in display that does NOT support any resolution but 2560x1440, so it must be scaled to get to HD.

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The problem I have, is that if I plug in a new display that has never been connected to the computer before, the configuration is all switched around, and sometimes unusable requiring manual editing of "displays.xml". They will use it to run our application, only our application and nothing else. The customer cannot be expected to even know that the command line exists, but they should be able to plug in any display and have the system work consistently.

I have tried enabling "Configure new displays when connected" as a workaround, and that is usually unable to cope with the changes. It will sometimes list a screen as disabled with no way to enable it, and it really does not like to scale the screen in increments of less than a tenth. (So 2560x1440 * 0.75 = 1920x1080 needs to be added to the "displays.xml" directly.) It will usually refuse to mirror displays.

I've completely given up on xorg.conf. If I set the viewport, the computer fails to boot completely, and must be recovered via live-usb. If I set it up with 3 displays, and unplug all but the primary display, then the primary display becomes the second screen, and there is no primary screen connected. So, that's why I'm focusing on xfce4-display-settings.

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All I want to do is make sure:

DP-0 is always the primary display and always 1920x1080 
DP-2 is always the mirror of the primary display and always 1920x1080 
HDMI-0 is always the extended to the right of the primary display and always 1920x1080 

I don't want anything to change if I swap out a Samsung TV for an ASUS Monitor or an HDMI switch that has never been connected before, but I should also be able to unplug anything but the primary display.

How can I make this work?