autocomplete: Options list can persistently lag behind query

[chrisbobbe]

It's normal for the options list to lag behind the query by some small amount, perhaps several milliseconds, because we do expensive filtering computations asynchronously.

The symptom here is different: for example, you type "@", and after waiting even multiple seconds, the list of @-mention autocomplete options doesn't come up. That's because RawAutocomplete updates the list with a listener on the TextEditingValue, not on the MentionAutocompleteView.

To recognize a change from one result set to another, we should have the UI listen and respond to MentionAutocompleteView, not TextEditingValue.

References

• Flutter issue for the needed upstream API: Rebuild Autocomplete options at arbitrary time flutter/flutter#159443

[chrisbobbe]

For a brain-dump of one possible approach, where we have RawAutocomplete grow a new feature, see discussion.

[chrisbobbe]

The symptom here is different: for example, you type "@", and after waiting even multiple seconds, the list of @-mention autocomplete options doesn't come up.

A user reported this symptom in beta feedback:

Also in the beta if you put the focus in the topic input you don’t get any propositions until you type something (and then remove it to see the list of all topics).

(They saw it with topic autocomplete, not @-mention autocomplete, but we use some of the same code for both and that code is where the bug is.)