I think we really should clean up the injected View fields. Touching the View fields in a background task is a very bad idea, also i think it is very rare. If somebody's app will break, he/she can examine the generated code. For clarification, i suggest to add some javadocs to the generated onDestroyView to explain the reason.

The background thread does not need to access views directly, it may just call a @UiThread-decorated method that will. I'll try to make the change you propose, but since I don't yet have deep understanding of how does AndroidAnnotations work, this may take a while.

Yes, you are right. To almost properly fix that issue, the developer can add @IgnoreWhenDetached annotation to the @UiThread decorated method, so it won't be called if the Fragment is detached. It will be still a problem if the method is called between onDestroyView and onDetach.

What would be the safe way then? A new annotation like @IgnoreWhenViewDestroyed?

Please review this commit carefully, as I may have missed something important.

I think this is good. But i would not merge without @yDelouis taking a look at this.

Wait, I think I did indeed miss something. Will push a commit in few minutes.

Good point, actually i was thinking about, too, but forgot to mention.
Can you squash the last two commits?

By cleaning injected views, we will make some existing app crash.
I'm ok with cleaning contentView_. But, shouldn't we wait for version 4.0 to be released to clean the injected views ?

@yDelouis, i guess you are right.

But we have to release 4.0.0 with the new plugin system. When do you have time to continue work on that?

Shall I make another PR only with the first (safe) commit then?

Yes, please.

Here it is: #1171

Great. Could you rebase this branch (since the first PR got merged)?

Rebased onto wrong branch, should be fine now.

Can you rebase this?

Rebased and merged as of faaaae5.