I've been very happy to see kiosk-shell get introduced in the past year or so.
It seems to tick nearly every box that I frequently find myself wanting when
trying to do embedded deployment of pre-existing Wayland apps which expect to
use the customary desktop-centric shells:
* declarative control over which output gets which surface
* force the apps full-screen by default
* no new protocols needed
So this is really nice. Much lower barrier to entry than IVI Shell, and
certainly a better re-use story for off-the-rack applications.
But there's a niche that doesn't have any obvious answer yet: controlling the
stacking order of different toplevel apps. It's fairly common to construct an
embedded system using distributed rendering from separate programs. This means
you need a way to control which things go above or below each other to achieve
the overall effect.
Would there be any interest in a contribution to enhance kiosk-shell to support
configurable stacking orders? This might take the form of either relative
specifications ("desktop surface XYZ always goes above desktop surface UWV") or
absolute z-order specifications ("desktop surface XYZ's surfaces go into
weston_layer #17").
I haven't thought deeply yet about how the syntax for setting the
stacking-order configuration in weston.ini would look. Maybe some kind of
subscript annotation following the surface ID?
[output]
name=LVDS1
# app1 goes in weston_layer 0. app2 goes in weston_layer 1
app-ids=org.domain.app1[0],com.domain.app2[1]
Or maybe allow more than one "app-ids" line, keyed by a subscript?
[output]
name=LVDS1
app-ids[layer0]=org.domain.app1,...
app-ids[layer1]=org.domain.app3,...
-Matt
