Let PackageKit trigger check_for_updates

[carniz]

An attempt at fixing #233

[leolost2605]

Hi @carniz, thanks for the PR!

A few notes:

• I think you can use Pk.offline_get_prepared_monitor instead of defining the file path to get the file monitor
• Instead of introducing revalidate_restart_required wouldn't it be enough to just force an update check? I.e. check_for_updates (true, true)
• get_current_state is called repeatedly when an operation is ongoing while the settings page is open so I wouldn't do something expensive there. Is that required? Shouldn't the file monitor be enough?

[carniz]

• I think you can use Pk.offline_get_prepared_monitor instead of defining the file path to get the file monitor

D'oh, that reduces the complexity. Good catch!

• Instead of introducing revalidate_restart_required wouldn't it be enough to just force an update check? I.e. check_for_updates (true, true)

Indeed, that's easier/simpler. I'll just let the monitor fire the update-check method.

• get_current_state is called repeatedly when an operation is ongoing while the settings page is open so I wouldn't do something expensive there. Is that required? Shouldn't the file monitor be enough?

Yeah, it's probably enough. The important thing is that PackageKit gets to be in charge, since failing to do so previously was what allowed for the inconsistent state.