Periodic discovery

[azymohliad]

A very basic periodic discovery is implemented. The current logic is the following:

• Periodic discovery is used only when running in the background, otherwise (if Devices view is open) it scans continuously as before.
• The intervals are hard-coded for now: 5 seconds scanning, 60 seconds pause.

TODO:

• Review the logic: is it adequate to switch between periodic and continuous discovery based solely on the UI visibility? Are there cases where we want periodic discovery in the foreground, or continuous discovery in the background?
• Review the default intervals. Should they be constant or ramp up over time? Should the first scan duration after startup or loosing the connection be longer than others?
• Add interval settings (maybe without a UI, gsettings backend only).
• Test thoroughly.
• (maybe) Make a Flathub CI build and ask more people to test before releasing.

[azymohliad]

Waiting to get some answers and gather a bit more information before continuing:

• StackOverflow
• Bluez Github Discussions