Closing Element closes background services

Hello,

I’m using Android 10 with Element from F-Droid store. When I’m closing the app from “Recent apps” menu, this also stops any background activity, such as listening for events. This was not the case for Android 8 + RiotX. Also, for example, Telegram FOSS (which also has custom push notifications mechanism and not firebase) doesn’t cancel event listening in this case.

Also Element does not appear in Developer options -> Running services unlike mentioned Telegram FOSS.

[andrewaylett]

My current understanding of this issue is that Element schedules synchronisation using a Worker or an Alarm, has a notification active while actually syncing, then schedules the next synchronisation. But if the system declines to run your worker, there’s no mechanism for restarting. I’ve had a play about with trying to add one (in #2921) but I’m not entirely clear that’s the direction to go in.

Also, we currently run the SyncService as a background service which runs a thread doing long-polling only while the application is in the foreground. From https://developer.android.com/guide/components/foreground-services?hl=en#start I think that it should be possible to run the SyncService as a foreground service even when not actively running the application. This would result in a persistent notification (which can be hidden) and an ongoing sync. As we’re long-polling, this wouldn’t use (much) more battery than FCM, even, and should help avoid the delay of restarting synchronisation when returning to the app.

[immanuelfodor]

Gotify Android (https://github.com/gotify/android), the self-hosted notification system, uses a websocket connection with its server + recommends disabling battery optimizations + utilizes a foreground notification for keepalive. In my experience, it uses minuscule battery over the day, doesn’t even show up on the battery stats page in Settings. However, I always receive every notification instantaneously.

Two takeaways:

• Maybe an optional minimized notification can keep Element running (could be turned on in app settings)
• A websocket-based notification method could be tudned on if Synapse or another used Matrix homeserver supported it. It could be a viable alternative to FCM notifications for users without Play services. It could also provide an alternative to privacy minded self-hosters even when they have Play services and even if they know that the notifications are also E2E encrypted but want to go for the all-selfhosted way.