fix: handle insertReplacementText for Korean IME on WKWebView/Safari#5704
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minemos wants to merge 4 commits into
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fix: handle insertReplacementText for Korean IME on WKWebView/Safari#5704minemos wants to merge 4 commits into
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WKWebView (used by Tauri, Capacitor, and Safari-based apps) does not fire
compositionstart/compositionupdate/compositionend events for Korean IME input.
Instead, it fires:
- insertText for initial jamo (e.g. 'ㅎ')
- insertReplacementText for composition updates (e.g. 'ㅎ' → '하' → '한')
Since _inputEvent only handles insertText, composed Korean syllables were
silently dropped, causing only raw jamo to reach the terminal.
This patch:
1. Buffers insertReplacementText data and shows composition preview
2. Intercepts Hangul insertText to buffer instead of sending immediately
3. Flushes the composed syllable on next non-IME keydown or new character
4. Adds wkImeComposing flag to CompositionHelper to suppress
_handleAnyTextareaChanges during synthetic WK composition
Tested with Korean (Hangul) IME in Tauri v2 (macOS WKWebView).
|
Thanks. This patch works fine for tauri 2.0. macos 26.3(25D125), safari, rust and tauri env. hope to merge this on later version xterm.js 6.x.x. |
Tyriar
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Mar 10, 2026
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| /** | ||
| * WKWebView IME workaround: holds the latest composed text from | ||
| * insertReplacementText events, flushed on next insertText or non-IME keydown. | ||
| */ | ||
| private _wkImeComposing: boolean = false; | ||
| private _wkImePending: string = ''; |
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I looked at how the events work Safari and it's unfortunate. How about instead of hardcoding this stuff into CoreBrowserTerminal, have a WkHangulCompositionEventEmulator that maps insertText/insertReplacementText events into compositionstart/update/end events? This class could then also be created only when it looks like webkit.
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I notice when finishing a character and moving onto the next, the next doesn't show until the second part is typed:
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Pressing ctrl+c while composing seems to duplicate the composing character:
bang9
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Mar 17, 2026
Apply changes from xtermjs/xterm.js#5704 as a pnpm patch. Adds WKWebView IME workaround that handles insertReplacementText events for Korean (Hangul) composition input, which WKWebView/Safari fires instead of standard composition events. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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dong-park
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Apr 16, 2026
WKWebView는 한글 IME에 compositionstart/end 이벤트를 발화하지 않아 xterm.js가 자모를 개별 전송하는 문제를 wk-hangul-ime 모듈로 해결. - wk-hangul-ime 모듈 추가 (github:thedalbee/wk-hangul-ime) - terminalManager.ts에 IME 핸들러 연결 - PTY spawn 시 LANG/LC_ALL UTF-8 로케일 설정 추가 Ref: xtermjs/xterm.js#5704 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
mvhenten
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Apr 28, 2026
Monkey-patch xterm.js 5.3.0 to fix three bugs on mobile: 1. Composition-based autocomplete: keyboards select all textarea content via compositionstart then replace it. xterm.js _finalizeComposition computes wrong substring offset, sending garbled partial text. Fix: detect selection at compositionstart, send proper diff at compositionend, block xterm.js stale send for 50ms. 2. Broken diff in _handleAnyTextareaChanges: uses String.replace which fails when autocorrect changes characters (not just appends). Fix: proper character-level prefix diff. 3. Backspace flood on Enter: _handleAnyTextareaChanges timer fires after xterm.js clears textarea, sending massive backspace sequence. Fix: skip when newValue is empty. Includes diagnostic logging to /api/debug endpoint (POST to debug-input.log) for ongoing mobile input debugging. Refs: xtermjs/xterm.js#5704, xtermjs/xterm.js#2403 Closes: #9
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Summary
WKWebView (used by Tauri, Capacitor, and Safari-based apps on macOS/iOS) does not fire
compositionstart/compositionupdate/compositionendevents for Korean IME input. Instead, it fires:insertTextwithinputType === 'insertText'for the initial jamo (e.g.ㅎ)insertReplacementTextfor composition updates (e.g.ㅎ→하→한)Since
_inputEvent()only handlesinputType === 'insertText', the composed Korean syllables frominsertReplacementTextwere silently dropped, causing only raw jamo to reach the terminal.Changes
CoreBrowserTerminal.ts(main fix):insertReplacementTextdata instead of dropping it, and show composition previewinsertText(before thecomposed/keyDownSeenguard) to buffer instead of sending immediately — WKWebView may setcomposed=trueon Hangul syllablesCompositionHelper.ts(minimal):wkImeComposingflag to suppress_handleAnyTextareaChanges()during synthetic WK composition (keyCode 229 would otherwise send individual jamo viasetTimeout)Types.ts/TestUtils.test.ts:wkImeComposingtoICompositionHelperinterface and mockHow it works
insertText "ㅎ"ㅎsent to PTYinsertReplacementText "하"하, preview updatedinsertReplacementText "한"한, preview updatedinsertText "..."한flushed to PTY, new buffer startedTesting
Tested with Korean (Hangul) IME in:
This fix is scoped to
insertReplacementTexthandling and Hangul detection, so it should not affect existing composition flows on Chrome/Firefox where standard composition events are fired.Fixes input for Korean IME users on Safari/WKWebView-based terminal applications.