Usually I have 3 external screens connected to a laptop with one panel on each screen (3 panels). After moving a laptop with 3 external screens to mobile use with internal screen only, the option "Output" of the panel settings has disappeared and there is no way to select the output of the 3 panels anymore. $ xfconf-query -c xfce4-panel -l |grep output /panels/panel-0/output-name /panels/panel-2/output-name /panels/panel-3/output-name These are all empty: $ for nr in 0 2 3;do xfconf-query -c xfce4-panel -p /panels/panel-$nr/output-name;done
This is not a bug. When there is only a single output connected what would you like to select there..?
For instance I would like to select that single current screen for my already configured panel that is not visible anymore.
I would say the problem is different from your original description then. Panels shall be moved back to the single output when all others are disabled.
Well, sometimes. To move all panels back to the new screen would be wrong. For instance: I like to move between multi-screen setup with screens A,B,C and mobile which is the internal screen D only. The internal screen is not part of the multi-screen setup. While having 3 panels for the multi-screen setup (1 panel per screen), I have a 4th panel for the mobile screen. Now on the road I notice I need a panel item from panel A that is already fully configured. For moving that item I need to display the panel A on screen D temporarily. I could re-create the panel item from scratch, but in order to add it to panel D I would need to delete it from the invisible panel A, and the configuration would be lost. So initially I just wondered that I can't get hold of that invisible panel A, just because I have only screen D available at the moment.
I think what actually covers your use case is not the output option of the panel, but xfpanel-switch: https://launchpad.net/xfpanel-switch It's already packaged in several distros and allows you to re/store panel configurations so you can e.g. quickly switch between your docking station and travelling setup.