Inrtoduce BrightnessManager dbus interface

[garaevdi]

With gnome 49 screen brightness management was moved into mutter. This is a simple and naive implementation of backlight interface which could be controlled via DBus.

Note: to build this you would need to compile mutter from git

[leolost2605]

Did you check whether it might already be exposed via org.gnome.mutter.displayconfig ?

[garaevdi]

Did you check whether it might already be exposed via org.gnome.mutter.displayconfig ?

Yes, but I think it's better to abstract it with a gala interface. Otherwise both switchboard-plug-power and wingpanel-power would need to implement the same things (handling monitors changes, converting raw brightness values to percentages).

_{Also you won't have to deal with complicated dbus types}