Swaybg not setting backgrounds for all workspaces

[coleslawsalad]

I'm using swaybg to set my background image at autostart. But this only works at the first workspace, not the other ones.

[phkaeser]

Thanks for reporting, @coleslawsalad .

This is a problem of the wlr layer shell not being aware of workspaces. And, turns out, an area that I haven't thought through very well. Writing down the thoughts:

1. The wlr layer shell layers apply to specific workspace each. (current behaviour)

   • Using swaybg then publishes a background image to the current workspace. It would need to be called for each workspace separately.
   • Similar for panels, docks, ... .

   Problem: There is no way to set eg. a background for all. Also, permitting a tool to define a background for a specific workpace would need a protocol extension.

2. The wlr layer shell layers apply to all workspaces consistently.

   • Using swaybg would publish the background image to all workspaces.
   • Panels, dock, ... (using other layers) would also apply to and be visible on all workspaces.

   Problem: Setting a background image per workspace will need a protocol extension.

3. Alternatively, find a way to explicitly make swaybg background updates apply to all workspaces, but keep the other layers bound to the specific workspace each.

   Problem: Inconsistent behaviour.

Seems it'll probably be easier to work with existing tools if the latter approach is chosen. And (later on) potentially extend with the option to set backgrounds specific to workspaces.

Implementation wise:

• Needs a significant rework of wlmtk_workspace_t, to factor out the layers.
• Both dock and clip will need some rework.