Feature discussion: DBus interface for monitoring/controlling app installations/states
In the Hack project we have currently a requirement for showing in an app (Flatpak) whether there's a new version of it available or not; and if a new version is being installed, then it should also display the percentage. The specific use-case is that for the Clubhouse app, we need to let the user know that they have a new version available, then direct them to update it in GNOME Software (or start the update from the Clubhouse app itself), and show that it's being updated (showing the percentage).
Very briefly summarized, currently there's no easy way to do this, so one solution would be to add a DBus interface for installing/removing apps, as well as monitoring their state/progress. This could be either implemented in GNOME Software or in Flatpak itself. If it is in Flatpak itself, then the feature will of source cover cases where apps are installed by other actors than GNOME Software (e.g. scripts, other app centers, etc.), and may somehow be easier to implement in that code-base than in GNOME Software, but I see pros and cons in both cases.
Since there's maybe some more interested parties in a feature like this, I would like to check the interest and opinions of the community, both GNOME Software and also Flatpak (if we can do it all here) regarding this functionality, and how feasible it seems.
CCing @hughsie , @alexl , @matthiasc , @klember .