Fatal 'getTextBeforeCursor on inactive InputConnection' error

[stemuk]

First of all, thanks a lot for this awesome project, I really appreciate the time and effort you must have put into zefyr to make this work!

In my own tests I ran into (only) one major issue that resolves around text input at a certain speed. If certain actions such as text input or or text deletion are preformed at a certain speed (for instance simply holding down the delete button on the keyboard) the entire application will crash and throw the following errors in frequent succession:

W/IInputConnectionWrapper( 5484): getTextBeforeCursor on inactive InputConnection
W/IInputConnectionWrapper( 5484): getSelectedText on inactive InputConnection
W/IInputConnectionWrapper( 5484): requestCursorAnchorInfo on inactive InputConnection

Even worse, the keybord will persist in its opened state even after the application has been closed by the user, as seen in this image, effectively rendering the device useless for several minutes.

The error might be caused by the race conditions you mentioned in #10 and seems to happen less frequently on more performant devices, which would suggest that performance optimizations might eliminate this issue for the most part.
Again, thanks a lot for creating this otherwise awesome widget, I think with the scope of this project issues like these are mostly unavoidable. 👍

[pulyaevskiy]

Thanks for reporting!

This does sound like possibly caused by a race condition.

Could you provide some more details, which would help me to reproduce it on my end:

1. Platform and device
2. Example code
3. A more detailed stack trace

You could also create a screen recording of the crash if it’s not too hard.

[pulyaevskiy]

So far I've found two issues in Flutter repo which refer to the same error: flutter/flutter#10498 and flutter/flutter#11198

Looks strange.

[stemuk]

The easiest way to reproduce the error is probably to spin up the zefyr example app on a local Android emulator and type or delete something quickly using the PC keyboard.
On my system the error occurs almost every time within a few seconds if I type or delete quickly enough. And while the error can be reproduced in release mode as well, it occurs much more frequently in slow mode which made me think that it is caused by a race condition.

[pulyaevskiy]

Oh, right, it's very easy to reproduce.

I also checked regular Flutter TextField and it doesn't suffer from this issue.
See #12 which should address this issue.

While debugging I noticed that even for every caret position change there were at least 3-4 exchanges between Dart and native sides, that was definitely not expected.

I'll publish an update later today.

[pulyaevskiy]

I just published 0.1.1 of zefyr package which should fix this issue. Please let me know how it goes for you!

[stemuk]

Ok, thanks a lot for the fix! 👍