Add automatic Downloads

[MidnightNerd]

This Pull request is related to #674.
There's one Problem the .pot file and the .po files aren't updated as i don't know where i can get the xml2po program.

[Lurux]

What happens if a user starts updating while the packages are still downloading in the background?

[MidnightNerd]

There is a lock in /var/cache/apt/archives/ so updates will fail.
A solution could be to download the files in a different directory and move them afterwards in /var/cache/apt/archives.
However this isn't the best solution as packages are downloaded twice in the case that updates are manually applied at the same as the automatic-download scripts downloads them.

The best solution would be to make apt wait for the lock to disappear.

By the way there's the same problem with automatic upgrades. When the automatic upgrades script is running it's nearly impossible to install new packages.

[Lurux]

Ok, I guess that makes sense. Ideally we'd want to hide the tray icon while the packages are downloading.

[Lurux]

Hey, just thought about something else. When the user starts installing updates, the update manager could interrupt the automatic download script and release the lock.

If everything goes well this should mean that the downloaded packages won't be downloaded twice, but this would prevent the updates from failing because of conflicting processes.

[clefebvre]

Is this ready for review? It looks ready to me.

I might mark it as Next for now (for Mint 21) since we've big WIP (flatpak support) coming up in the next release and we'll be doing a lot of testing.

I'm wondering also whether or not we need multiple timers for this. This feature is only useful when automatic upgrades are OFF right? So it would make sense from a user point of view to look at a combo here...

Apply updates automatically?

• No
• Download Only
• Yes

And a single timer would suffice to take care of that job. If the service can find the chosen policy, we don't even need to play with the timer, it can remain active all the time.

[carlosmintfan]

@MidnightNerd could you make one switch with a combo here instead of these two toggles? (Or let me do the job...) 😃

[MidnightNerd]

@carlosmintfan @clefebvre Sorry for not answering so long. The ComboBox is now implemented.