On slow internet, Mark article as read action is blocking UI

[Strubbl]

When i am on a real unresponsive, slow internet network connection (2G) and i hit the button to mark an article as read, the UI is frozen until the article is marked as read. In the meantime Android system suggests to wait or close the app. If you wait, some more seconds later the article is marked as read and you can go on using the app.

Is there any improvement in this issue when #621 is implemented?

[di72nn]

I can't remember all the details now, but some operations are mutually-exclusive in terms of DB access, so in some cases actions stuck waiting for the previous operation to complete. I think the article lists should load regardless of other operations, but it is the "mark as read" action that is stuck (maybe there is a sync in the background). So the test case should be something like that:

1. Start sync on a slow network.
2. Open an article.
3. Perform some modifying action ("mark as read", "favorite", "delete", etc.).

Result: the UI is stuck. More precisely, the ArticleReadActivity is waiting for the operation from step 3 to complete, the operation is waiting for the sync to complete.

The fix for that is a bit complex. Some long operations should probably be rewritten into a bunch of smaller ones ("article downloading", "queue sync"), some mutual exclusiveness should be checked and maybe eliminated (like "queue sync" should not block adding to local queue).

#621 doesn't touch that.

[di72nn]

Fixed in #931.