fix(terminal): draw IME preview after local-echo text

With local echo on, committed text sits in the LocalEchoOverlay and does not
reach the PTY before Enter, so the PTY cursor that places the preview span
stays at the prompt start. The span's z-index 6 only counts inside
.xterm-helpers (its own z-index 5 stacking context), and the overlay is a
z-index 7 layer whose first line is opaque from the prompt column, so every
composition after the first one in a prompt was drawn under the overlay.

- xterm-zerolag-input: add setComposition(text) and a composition getter.
  The overlay draws the composition as an underlined, aria-hidden tail after
  its pending text, through the same wrapping and grow-upward layout. It is
  never part of pendingText, hasPending or anything sent; clear() and
  removeChar() drop it, and rerender()/refreshFont() keep it.
- terminal-ui.js: while local echo shows typed text (on, and not handed back
  to PTY echo by a nav key), render and clear the preview through
  setComposition. The helper span stays for local echo off, and as the
  fallback when the overlay cannot place the text (no prompt found).
- Browser test against real xterm 6, the overlay bundled from its source
  and styles.css: a second composition after pending text is the topmost
  element after that text, and the commit lands in the overlay once. Unit
  tests for setComposition in the package and for the routing in the
  structure test.
- CLAUDE.md and architecture-invariants: state the preview's effective layer.
This commit is contained in:
Aamer Akhter
2026-09-27 07:56:22 -04:00
parent 2d96472dbe
commit ee1a155e2c
9 changed files with 579 additions and 18 deletions
+164
View File
@@ -15,7 +15,9 @@
* npm run test:browser -- test/mobile-ime-preview.browser.test.ts
*/
import { readFileSync } from 'node:fs';
import { resolve } from 'node:path';
import { build } from 'esbuild';
import { afterAll, beforeAll, describe, expect, it } from 'vitest';
import { chromium, type Browser, type Page } from 'playwright';
@@ -126,3 +128,165 @@ describe('mobile IME preview with real xterm', () => {
expect(result.state).toMatchObject({ awaitingCommit: false, committed: false });
});
});
/**
* The preview with local echo ON, the default for Claude sessions on phones.
* Committed text then sits in the LocalEchoOverlay (a z-index 7 layer in
* `.xterm-screen`) and never reaches the PTY before Enter, so the PTY cursor,
* which is where the helper span sits, stays at the prompt start: under the
* overlay's own opaque text. So a composition that follows text already in the
* overlay must be drawn by the overlay itself, after that text.
*
* Loads the real pieces: xterm 6, the overlay bundled from its package source
* exactly as scripts/postinstall.js bundles it (plus the same LocalEchoOverlay
* alias), styles.css, mobile-ime-preview.js, and terminal-ui.js's own
* `_initMobileImePreview` on a bare CodemanApp prototype.
*/
describe('mobile IME preview over the local echo overlay', () => {
let browser: Browser;
let page: Page;
beforeAll(async () => {
const bundled = await build({
entryPoints: [resolve(root, 'packages/xterm-zerolag-input/src/zerolag-input-addon.ts')],
bundle: true,
format: 'iife',
globalName: 'XtermZerolagInput',
write: false,
logLevel: 'silent',
});
const overlayBundle =
bundled.outputFiles[0].text +
'\nwindow.ZerolagInputAddon=XtermZerolagInput.ZerolagInputAddon;' +
'window.LocalEchoOverlay=class extends XtermZerolagInput.ZerolagInputAddon{' +
'constructor(terminal){super({prompt:{type:"character",char:"\\u276f",offset:2}});this.activate(terminal);}};\n';
browser = await chromium.launch({ headless: true });
page = await browser.newPage({ viewport: { width: 800, height: 400 }, deviceScaleFactor: 1 });
await page.setContent(
'<html class="touch-device"><body><div id="t" style="width:600px;height:240px"></div></body></html>'
);
await page.addStyleTag({ path: resolve(root, 'node_modules/@xterm/xterm/css/xterm.css') });
await page.addStyleTag({ content: readFileSync(resolve(root, 'src/web/public/styles.css'), 'utf8') });
await page.addScriptTag({ path: resolve(root, 'node_modules/@xterm/xterm/lib/xterm.js') });
await page.addScriptTag({ content: overlayBundle });
await page.addScriptTag({ path: resolve(root, 'src/web/public/mobile-ime-preview.js') });
await page.addScriptTag({ content: 'window.CodemanApp = class CodemanApp {};' });
await page.addScriptTag({ path: resolve(root, 'src/web/public/terminal-ui.js') });
}, 60000);
afterAll(async () => {
if (browser) await browser.close();
});
/**
* Types `pending` into the overlay (as the printable/paste branch does), then
* composes `composing` and reports what is PAINTED at the cell right after
* the pending text and at the PTY cursor. Painted = topmost by hit-testing
* with pointer-events forced on, since the overlay and the preview are
* pointer-events:none.
*/
async function composeAfter(pending: string, composing: string, commit: boolean) {
return page.evaluate(
async ({ pending, composing, commit }) => {
const w = window as any;
const host = document.getElementById('t') as HTMLElement;
host.innerHTML = '';
const term = new w.Terminal({
cols: 40,
rows: 8,
fontSize: 14,
fontFamily: 'monospace',
allowProposedApi: true,
});
term.open(host);
await new Promise<void>((r) => term.write('\u276f ', () => r()));
const app = new w.CodemanApp();
app.terminal = term;
app._localEchoEnabled = true;
app._localEchoOverlay = new w.LocalEchoOverlay(term);
w.MobileImePreview.isIosWebKitTouch = () => true;
app._initMobileImePreview();
// The helper textarea and span follow the PTY cursor (col 2, row 0), as
// _syncMobileHelperTextareaToCursor places them.
const screen = term.element.querySelector('.xterm-screen') as HTMLElement;
const dims = term._core._renderService.dimensions.css.cell;
term.element.style.setProperty('--xterm-helper-left', 2 * dims.width + 'px');
term.element.style.setProperty('--xterm-helper-top', '0px');
if (pending) app._localEchoOverlay.appendText(pending);
const textarea = term.textarea as HTMLTextAreaElement;
textarea.focus();
textarea.dispatchEvent(new CompositionEvent('compositionstart', { data: '' }));
textarea.value = composing;
textarea.dispatchEvent(new CompositionEvent('compositionupdate', { data: composing }));
await new Promise((r) => requestAnimationFrame(() => setTimeout(r, 20)));
const force = document.createElement('style');
force.textContent = '.xterm * { pointer-events: auto !important; }';
document.head.appendChild(force);
const rect = screen.getBoundingClientRect();
const widthOf = (s: string) => term._core.unicodeService.getStringCellWidth(s);
const paintedAt = (col: number) => {
const el = document.elementFromPoint(
rect.left + (col + 0.5) * dims.width,
rect.top + 0.5 * dims.height
) as HTMLElement | null;
return {
text: el?.textContent ?? null,
composition: !!el?.closest?.('[data-zerolag-composition]'),
preview: !!el?.closest?.('.codeman-ime-preview'),
};
};
const afterPending = paintedAt(2 + widthOf(pending));
force.remove();
let afterCommit = null;
if (commit) {
textarea.dispatchEvent(new CompositionEvent('compositionend', { data: composing }));
// What the printable/paste branch of terminal-ui.js's onData does.
if (app._consumeMobileImeTerminalData(composing)) {
app._localEchoOverlay.appendText(composing);
app._transferMobileImeCommitToLocalEcho();
}
await new Promise((r) => requestAnimationFrame(() => setTimeout(r, 20)));
afterCommit = {
pendingText: app._localEchoOverlay.pendingText,
compositionSpans: term.element.querySelectorAll('[data-zerolag-composition]').length,
overlayText: app._localEchoOverlay._overlay?.textContent,
};
}
const result = {
afterPending,
pendingText: app._localEchoOverlay.pendingText,
afterCommit,
};
app._destroyMobileImePreview();
app._localEchoOverlay.dispose();
term.dispose();
return result;
},
{ pending, composing, commit }
);
}
it('first composition on an empty prompt: the overlay draws it at the prompt', async () => {
const result = await composeAfter('', '今日は', false);
expect(result.afterPending).toEqual({ text: '今', composition: true, preview: false });
expect(result.pendingText).toBe('');
});
it('a second composition is painted after the text already in the overlay, not under it', async () => {
const result = await composeAfter('今日は', '天気', false);
expect(result.afterPending.text).toBe('天');
expect(result.afterPending.composition).toBe(true);
// Provisional text is never taken into the overlay's pending (unsent) text.
expect(result.pendingText).toBe('今日は');
});
it('the commit lands once in the overlay and the composition tail is gone', async () => {
const result = await composeAfter('今日は', '天気', true);
expect(result.afterCommit).toEqual({ pendingText: '今日は天気', compositionSpans: 0, overlayText: '今日は天気' });
});
});