force_english_ime 0.0.4

A Windows plugin for Flutter that forces English input mode by completely disabling IME. Prevents users from switching input methods via shortcuts like Shift or Ctrl+Space.

force_english_ime

中文文档

A Windows plugin for Flutter that forces English input mode by completely disabling IME. Prevents users from switching input methods via shortcuts like Shift or Ctrl+Space.

Features

• ✅ Complete IME Disable - Uses ImmAssociateContext to completely disable IME
• ✅ Automatic State Management - Auto-save and restore IME state
• ✅ Accurate Detection - Precise input mode detection using ImmGetConversionStatus
• ✅ Real-time Monitoring - Listen to IME state changes via onImeStateChanged stream
• ✅ Emergency Recovery - Use cancelForceEnglish() to re-enable IME when stuck
• ✅ Zero Dependencies - Only uses Windows IMM API
• ✅ Easy Integration - Simple API with Focus widget support

Platform Support

Platform	Support
Windows	✅
macOS	❌
Linux	❌
Android	❌
iOS	❌

Installation

Add to pubspec.yaml:

dependencies:
  force_english_ime: ^0.0.4

Then run:

flutter pub get

Quick Start

Basic Usage

import 'package:force_english_ime/force_english_ime.dart';

final _imePlugin = ForceEnglishIme();

// Check if English IME
bool isEnglish = await _imePlugin.isEnglishIme();

// Force English input
await _imePlugin.forceEnglishInput();

// Restore original IME
await _imePlugin.restoreOriginalIme();

// Emergency: re-enable IME with a fresh context (when restoreOriginalIme fails)
await _imePlugin.cancelForceEnglish();

Use with TextField

class EmailInput extends StatefulWidget {
  @override
  State<EmailInput> createState() => _EmailInputState();
}

class _EmailInputState extends State<EmailInput> {
  final _imePlugin = ForceEnglishIme();
  final _controller = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Focus(
      onFocusChange: (hasFocus) {
        if (hasFocus) {
          _imePlugin.forceEnglishInput();
        } else {
          _imePlugin.restoreOriginalIme();
        }
      },
      child: TextField(
        controller: _controller,
        decoration: const InputDecoration(
          labelText: 'Email',
          hintText: '[e-mail]',
        ),
      ),
    );
  }
}

Listen to IME State Changes

final ime = ForceEnglishIme();

ime.onImeStateChanged.listen((event) {
  switch (event['type']) {
    case 'conversionModeChanged':
      print('Alphanumeric: ${event['isAlphanumeric']}');
      break;
    case 'openStatusChanged':
      print('IME open: ${event['isOpen']}');
      break;
    case 'inputLanguageChanged':
      print('Language: ${event['languageTag']}');
      break;
  }
});

API Reference

Methods

Future<bool> isEnglishIme()

Check if current IME is in English mode.

Returns: true if in English mode, false otherwise.

Future<bool> forceEnglishInput()

Force English input by completely disabling IME.

Returns: true if successful, false otherwise.

Future<bool> restoreOriginalIme()

Restore the original IME state.

Returns: true if successful, false otherwise.

Future<bool> cancelForceEnglish()

Re-enable IME by creating a fresh IME context. Unlike restoreOriginalIme, this does not attempt to restore the previous state.

Returns: true if successful, false otherwise.

Streams

Stream<Map<String, dynamic>> onImeStateChanged

A stream of real-time IME state change events.

Event types:

Type	Description	Data
conversionModeChanged	Input mode toggled (English ↔ native)	{ isAlphanumeric: bool }
openStatusChanged	IME opened or closed	{ isOpen: bool }
inputLanguageChanged	System input language changed	{ languageId: int, languageTag: String }

Use Cases

• 📧 Email input
• 👤 Username input
• 🔗 URL input
• 💻 Code editor
• 🔑 API key input
• And more...

How It Works

This plugin uses Windows IMM (Input Method Manager) API:

• ImmAssociateContext(hwnd, NULL) - Completely disables IME
• ImmCreateContext() - Creates a fresh IME context for recovery
• ImmGetConversionStatus() - Detects input mode
• GetFocus() - Gets current focused control
• SetWindowSubclass - Intercepts WM_IME_NOTIFY and WM_INPUTLANGCHANGE for real-time monitoring

When IME is disabled, users cannot switch input methods via any shortcuts (Shift, Ctrl+Space, etc.).

Examples

Check out the example directory for a complete demo app.

Requirements

• Flutter SDK: >= 3.0.0
• Dart SDK: >= 2.17.0
• Windows 10 or higher recommended

License

MIT License - see LICENSE file for details.

Contributing

Issues and Pull Requests are welcome!

Links

• pub.dev
• GitHub Repository
• Issue Tracker