notepad++: Editing Chinese letters, NVDA fails to track caret movements within "uncommitted" IME composition strings

[surfer0627]

In Scintilla-based editors such as Notepad++, while editing Chinese characters, NVDA fails to announce caret movements or update the Braille display; specifically, this issue occurs only within the uncommitted text string during an active IME composition.

This issue was originally posted on this page comment 2.

Step to reproduce:

1. Open notepad++
2. Press alt + shift to switch input method
3. Press shift to native input
4. Typing Chinese letters 烏龜
   Note: Do not press Enter; keep the text in the "uncommitted" state (composition string).
5. Press left-arrow

Actual behavior:

speech: blank
braille: no feedback

Expected behavior:

Speech: Should report the character at the caret (e.g., "龜").

Braille: Should correctly display the composition character and its dot patterns (e.g., 13 1246 3).

NVDA logs

• nvda.log

line 690

System configuration

NVDA installed/portable/running from source:

portable

NVDA version:

alpha-54324,94ea0f6f (2026.2.0.54324)

Windows version:

Windows 11 24H2 (AMD64) build 26100.7462

Name and version of other software in use when reproducing the issue:

• Notepad++ 8.9.1 portable.x64

Technical Observations:

I suspect this issue is closely related to the changes introduced in PR 13364. While that PR successfully prevented crashes in 64-bit Notepad++ 8.3+ by implementing ScintillaTextInfoNpp83, it appears to have created an unintended conflict with NVDA's IME handling logic.

• TextInfo Precedence: In appModules/notepadPlusPlus.py, the NppEdit class explicitly returns ScintillaTextInfoNpp83 for version 8.3+. This seems to prevent NVDA from falling back to InputCompositionTextInfo during an active IME session.
• Proposed Logic: Would it be feasible to modify _get_TextInfo to prioritize InputCompositionTextInfo whenever compositionString is active, before falling back to the version-specific Scintilla logic?

Other questions

Does the issue still occur after restarting your computer?

Yes.

Have you tried any other versions of NVDA? If so, please report their behaviors.

This problem didn't occur with 2021.3.

It occurs with 2022.1 and later.

If addons are disabled, is your problem still occuring?

Yes.

Did you try to run the COM registry fixing tool in NVDA menu / tools?

No.

input method:

Chinese New Phonetic)

possible issues:

from the fixed issues, could we try to find one way to describe this bug?

• Editing Korean letters with NVDA and braille display issue. · Issue #5640
• Panning braille past the visible text in Scintilla doesn't update the braille display · Issue #5678

[Adriani90]

cc: @cary-rowen, @hwf1324, @surfer0627, @CrazySteve0605 is this issue still reproducible in NVDA last 64 bit alpha or NVDA from PR #19166 and last version of Notepad++?

[cary-rowen]

I have never encountered this bug before, and I am unable to reproduce it.

[Adriani90]

I am closing this issue as works for me given the comment above. if anyone on Windows 11 has this issue still, please comment and we can reopen. Support for Windows 10 has ended in Oktober 2025.

[surfer0627]

Preliminary technical findings regarding the Scintilla IME issue:

As a user affected by this issue, I’ve tried to perform some preliminary investigation using the Developer Info. I am not a developer, so please forgive any misunderstandings of the internal logic, but I hope these observations might be helpful for the team:

I noticed that InputCompositionTextInfo in inputComposition.py is responsible for fetching the uncommitted strings via _getStoryText. The NoneType exception I observed might be related to _getSelectionOffsets returning an unexpected value during _getCaretOffset calculation when running in the Notepad++ Scintilla environment.

• Event Consistency: Interestingly, the log still shows Caret move detected. This makes me wonder if the event is firing correctly, but the "bridge" to the actual text content is temporarily disconnected.

• Observation on Object MRO: I noticed the object is identified as Dynamic_NppEditInputCompositionInputComposition. It seems to be using ScintillaTextInfoNpp83 even during composition, which might be why it struggles to read the uncommitted text string.

• Note on the Exception: I encountered an error: displayText: exception: cannot unpack non-iterable NoneType object. My guess is that this might happen in inputComposition.py if a text offset or coordinate returns None during the composition update.

I hope these small clues can save you some time in investigating the problem. Thank you for all your hard work on NVDA!

[hwf1324]

I cannot reproduce this issue in SciTE version 5.5.8 Scintilla:5.5.8 Lexilla:5.4.6.