[Windows 7][Desktop]: Unable to input chinese from TextFormField widget on win7 OS with Sogou IME

[wujing-gxl]

Steps to Reproduce

Always fail on win7 system，win10 is ok，see the gif：

Expected results:
TextFormField input：“好的”

Actual results:
TextFormField input：“hd”

Logs

flutter doctor -v
[√] Flutter (Channel stable, 2.5.3, on Microsoft Windows [Version 10.0.17763.2183], locale zh-CN)
    • Flutter version 2.5.3 at D:\thirdsdk\flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 18116933e7 (5 days ago), 2021-10-15 10:46:35 -0700
    • Engine revision d3ea636dc5
    • Dart version 2.14.4

[!] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
    • Android SDK at C:\Users\wujing\AppData\Local\Android\sdk
    X cmdline-tools component is missing
      Run `path/to/sdkmanager --install "cmdline-tools;latest"`
      See https://developer.android.com/studio/command-line for more details.
    X Android license status unknown.
      Run `flutter doctor --android-licenses` to accept the SDK licenses.
      See https://flutter.dev/docs/get-started/install/windows#android-setup for more details.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Visual Studio - develop for Windows (Visual Studio Community 2019 16.10.4)
    • Visual Studio at C:\Program Files (x86)\Microsoft Visual Studio\2019\Community
    • Visual Studio Community 2019 version 16.10.31515.178
    • Windows 10 SDK version 10.0.19041.0

[√] Android Studio (version 2020.3)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin can be installed from:
       https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
       https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7249189)

[√] VS Code (version 1.61.1)
    • VS Code at C:\Users\wujing\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.27.0

[√] Connected device (2 available)
    • Windows (desktop) • windows • windows-x64    • Microsoft Windows [Version 10.0.17763.2183]
    • Chrome (web)      • chrome  • web-javascript • Google Chrome 94.0.4606.81

! Doctor found issues in 1 category.

[darshankawar]

Since I don't have Windows 7 to verify, I can't replicate this. Keeping it open for further insights from the team.

/cc @cbracken

[cbracken]

Copying from #85878:

@Jasonnnn wrote:
When I use Sogou input method to input text on win7, I can only get composition string instead of Chinese characters.
I'm using flutter 2.2.0 now;
However, it works fine on flutter 1.22.4.

When I am sure of the Chinese characters I want, this method
Future _ Handletextinputinvocation (methodcall methodcall) async {},only gives me composition string.
So I guess it's related to flutter Engine.
This problem only appears on win7, and win10 runs very well

Since this has a video and repro steps, keeping this one open and closing the other.

[cbracken]

Tagging #92050 for x-reference. That one is a cosmetic issue affecting Win10, but also Sogou input method.

For anyone working on this, the Sogou IME can be installed from https://pinyin.sogou.com/

[cbracken]

@wujing-gxl can you:

• attach a code sample that reproduces this
• paste your flutter doctor output from the Windows 7 machine where this fails?

I was able to get a Windows 7 SP1 machine set up running Flutter and with Sogou installed, but it appears to work for me:

Here's my Flutter doctor output:

PS C:\src\jp_flutter> flutter doctor
Building flutter tool...
Running pub upgrade...
Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel master, 2.6.0-12.0.pre.478, on Microsoft Windows [Version 6.1.7601], locale en-US)
[X] Android toolchain - develop for Android devices
    X Unable to locate Android SDK.
      Install Android Studio from: https://developer.android.com/studio/index.html
      On first launch it will assist you in installing the Android SDK components.
      (or visit https://flutter.dev/docs/get-started/install/windows#android-setup for detailed instructions).
      If the Android SDK has been installed to a custom location, please use
      `flutter config --android-sdk` to update to that location.

[X] Chrome - develop for the web (Cannot find Chrome executable at .\Google\Chrome\Application\chrome.exe)
    ! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.
[√] Visual Studio - develop for Windows (Visual Studio Community 2019 16.11.5)
[!] Android Studio (not installed)
[√] Connected device (1 available)

! Doctor found issues in 3 categories.

[cbracken]

Update here -- I misread part of the original report. I am now able to repro this. The IME candidates list comes up and is keyboard-navigable, but selecting a candidate (either by pressing space, or clicking it in the IME) seems to just end composing instead of replacing the composing range with the result string from the candidates list.

Steps:

1. Focus the text field
2. Ensure IME is set to sogou
3. Input some text (e.g. nihao). The candidates list will appear. Arrow keys work for navigating the candidates list.
4. Either click the candidate or press enter.

Expected behaviour: Composing text is replaced with the selected candidate
Actual behaviour: Composing ends. Text remains unchanged.

A couple notes to myself or whoever implements this fix:

• We currently update the composing range on every WM_IME_COMPOSITION event.
• We do NOT update the composing range on WM_IME_ENDCOMPOSITION events.
• It's probably worth checking whether it makes a difference if we invoke the OnImeComposition handler in the WM_IME_ENDCOMPOSITION event handler.

[cbracken]

I did try out blindly patching in an OnImeComposition call in the WM_IME_ENDCOMPOSITION handler as discussed above, but this didn't work. I haven't looked into this further than that or tried debugging. Just a quick update since I'm jumping back to another bug.

[gspencergoog]

When I try to reproduce this with Sogou, the candidate list disappears when a candidate is selected, but the composing text is also removed from the field (if I started typing with an empty field, it remains empty once I select a candidate). The candidate text does appear in the field while the candidate list is up.

If I use the Windows IME (PRC Simplified, "New Experience" mode), then things appear to operate correctly (although I'm far from an experienced IME user).

(Windows 7 Professional SP1)

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.