fix(mobile): prevent terminal tap selection

src/web/public/styles.css

@@ -2246,6 +2246,23 @@ body.solo-mode .btn-lifecycle-log {
   touch-action: none;
 }
 
+/* Mobile terminal taps are cursor-positioning gestures, not text-selection gestures.
+   xterm re-enables selectable DOM text in its accessibility tree, so force the
+   whole terminal subtree back to non-selectable on touch devices. Synthetic mouse
+   events for tap-to-position still dispatch normally through JavaScript. */
+body.touch-device .terminal-container .xterm,
+body.touch-device .terminal-container .xterm .xterm-viewport,
+body.touch-device .terminal-container .xterm .xterm-screen,
+body.touch-device .terminal-container .xterm .xterm-rows,
+body.touch-device .terminal-container .xterm .xterm-accessibility-tree,
+body.touch-device .terminal-container .xterm .xterm-accessibility-tree *,
+body.touch-device .terminal-container .xterm .xterm-selection,
+body.touch-device .terminal-container .xterm .xterm-helper-textarea {
+  user-select: none !important;
+  -webkit-user-select: none !important;
+  -webkit-touch-callout: none !important;
+}
+
 /* Welcome Overlay */
 .welcome-overlay {
   position: absolute;

src/web/public/terminal-ui.js

@@ -19,6 +19,10 @@
   // suppressed, so high-frequency Codex status redraws don't snap the viewport
   // back to the bottom while the user is inspecting earlier output.
   const USER_SCROLL_STICKY_SUPPRESS_MS = 1500;
+  // Mobile browsers synthesize trusted mouse events after touchend. During this
+  // short window, only the app's synthetic tap-to-position mouse event should
+  // reach xterm.
+  const TOUCH_COMPAT_MOUSE_SUPPRESS_MS = 450;
 
   function isTerminalQueryResponse(data) {
     return TERMINAL_QUERY_RESPONSE_PATTERN.test(data) || TERMINAL_OSC_RESPONSE_PATTERN.test(data);
@@ -46,6 +50,7 @@
     isTerminalQueryResponse,
     shouldSuppressTerminalQueryResponse,
     USER_SCROLL_STICKY_SUPPRESS_MS,
+    TOUCH_COMPAT_MOUSE_SUPPRESS_MS,
   };
   global.CODEMAN_XTERM_THEMES = CODEMAN_XTERM_THEMES;
   global.codemanCurrentXtermTheme = currentXtermTheme;
@@ -107,6 +112,7 @@ Object.assign(CodemanApp.prototype, {
 
     const container = document.getElementById('terminalContainer');
     this.terminal.open(container);
+    this._installMobileTapMouseGuard();
 
     // Suppress xterm key handling during CJK IME composition.
     // Without this, xterm processes raw keyDown events (e.g., "Process" key)
@@ -425,16 +431,32 @@ Object.assign(CodemanApp.prototype, {
             scrollFrame = requestAnimationFrame(scrollLoop);
           }
           if (!didScroll && this.terminal) {
+            // ── Tap-to-position cursor ──────────────────────────────────
+            // Synthesize a click from the real touch point so the foreground app
+            // moves its cursor to the tapped cell (iOS doesn't reliably do this
+            // itself under touch-action:none). CRITICAL: only when mouse tracking
+            // is ON. xterm disables its local SelectionService while mouse events
+            // are active, so the synthetic click is forwarded to the PTY as an SGR
+            // report (cursor moves). But when tracking is OFF, that same click
+            // drives xterm's LOCAL selection (detail 1/2/3 → char/word/line) — a
+            // tap on CJK text would select & copy it instead of positioning. So
+            // gate strictly on the live mouse-tracking mode.
+            const touch = ev.changedTouches && ev.changedTouches[0];
+            const mouseMode = this.terminal.modes?.mouseTrackingMode;
+            const mouseTrackingOn = !!mouseMode && mouseMode !== 'none';
+            if (touch) {
+              this._suppressTrustedTapMouseEvents();
+            }
+            if (touch && mouseTrackingOn) {
+              this._dispatchSyntheticTerminalClick(touch.clientX, touch.clientY);
+            }
+            this._syncMobileHelperTextareaToCursor();
+            // Route subsequent typing to the right place: keep the CJK input
+            // field focused when Chinese input is on, otherwise the terminal.
             const cjkInput = document.getElementById('cjkInput');
             if (cjkInput?.classList.contains('cjk-input-visible')) {
               cjkInput.focus();
             } else {
-              // Don't synthesize mousedown — the browser does it naturally
-              // because we don't preventDefault() for taps (< TAP_THRESHOLD).
-              // touch-action:none blocks native scroll but NOT click synthesis.
-              // The browser's mousedown carries detail:1 + correct coordinates,
-              // so xterm's SelectionService._handleSingleClick picks it up.
-              this._syncMobileHelperTextareaToCursor();
               this.terminal.focus();
             }
           }
@@ -596,8 +618,13 @@ Object.assign(CodemanApp.prototype, {
     // survives tab switches and reconnects.
 
     this.terminal.onData((data) => {
-      // CJK input has focus — block xterm from sending to PTY
+      // Mouse SGR reports (tap-to-position) are NOT IME input — they must reach
-      if (window.cjkActive || document.activeElement?.id === 'cjkInput') return;
+      // the PTY even while the CJK input field owns focus. Without this exception
+      // tapping to move the cursor silently does nothing whenever Chinese input
+      // is on, because cjkActive stays true the whole time the field is visible.
+      const isMouseReport = /^\x1b\[<\d+;\d+;\d+[Mm]$/.test(data);
+      // CJK input has focus — block xterm from sending keystrokes to PTY
+      if (!isMouseReport && (window.cjkActive || document.activeElement?.id === 'cjkInput')) return;
       if (this.activeSessionId) {
         // Filter terminal query replies generated by xterm.js itself.
         // Forwarding them through the WebSocket injects DA/DSR/CPR replies
@@ -2005,6 +2032,62 @@ Object.assign(CodemanApp.prototype, {
     } catch {}
   },
 
+  // ═══════════════════════════════════════════════════════════════
+  // Synthetic tap → mouse report
+  // ═══════════════════════════════════════════════════════════════
+  // Dispatch a mousedown+mouseup pair at viewport coords (clientX/clientY) to
+  // xterm's root element. xterm's mouse-reporting handler reads the event's
+  // client coords, maps them to a terminal cell relative to .xterm-screen, and
+  // — when the foreground app has mouse tracking active (DECSET 1000/1002/1006,
+  // which Claude's input enables) — encodes an SGR mouse report to the PTY.
+  // That is the same path a real desktop click takes; on touch devices the
+  // browser's own compatibility-event synthesis is unreliable (and suppressed
+  // by touch-action:none), so we drive it explicitly. With mouse tracking off
+  // it degrades to a harmless zero-length click (no drag → no text selection).
+  _dispatchSyntheticTerminalClick(clientX, clientY) {
+    const el = this.terminal?.element;
+    if (!el || !Number.isFinite(clientX) || !Number.isFinite(clientY)) return;
+    // xterm registers its mouseup listener on document during mousedown, so a
+    // bubbling mouseup reaches it; dispatch both to the root element in order.
+    const base = {
+      bubbles: true,
+      cancelable: true,
+      view: window,
+      clientX,
+      clientY,
+      screenX: clientX,
+      screenY: clientY,
+      button: 0,
+      detail: 1,
+    };
+    try {
+      el.dispatchEvent(new MouseEvent('mousedown', { ...base, buttons: 1 }));
+      el.dispatchEvent(new MouseEvent('mouseup', { ...base, buttons: 0 }));
+    } catch {
+      /* MouseEvent constructor unavailable — tap-to-position simply no-ops */
+    }
+  },
+
+  _installMobileTapMouseGuard() {
+    const el = this.terminal?.element;
+    if (!el || el._codemanTapMouseGuardInstalled) return;
+    if (typeof MobileDetection !== 'undefined' && MobileDetection.isTouchDevice && !MobileDetection.isTouchDevice()) return;
+    el._codemanTapMouseGuardInstalled = true;
+    const suppressTrustedCompatMouse = (ev) => {
+      const suppressUntil = this._trustedTapMouseSuppressUntil || 0;
+      if (!ev.isTrusted || performance.now() > suppressUntil) return;
+      ev.preventDefault();
+      ev.stopImmediatePropagation();
+    };
+    el.addEventListener('mousedown', suppressTrustedCompatMouse, true);
+    el.addEventListener('mouseup', suppressTrustedCompatMouse, true);
+  },
+
+  _suppressTrustedTapMouseEvents() {
+    const ms = window.CodemanTerminalInput?.TOUCH_COMPAT_MOUSE_SUPPRESS_MS || 450;
+    this._trustedTapMouseSuppressUntil = performance.now() + ms;
+  },
+
   increaseFontSize() {
     const current = this.terminal.options.fontSize || 14;
     this.setFontSize(Math.min(current + 2, 24));

test/terminal-touch-tap.test.ts

@@ -0,0 +1,116 @@
+import { readFileSync } from 'node:fs';
+import { resolve } from 'node:path';
+import vm from 'node:vm';
+import { describe, expect, it, vi } from 'vitest';
+
+function loadTerminalUiHarness() {
+  const CodemanApp = function CodemanApp(this: any) {};
+  let now = 1_000;
+  const context = vm.createContext({
+    window: {},
+    CodemanApp,
+    console: { warn: vi.fn(), log: vi.fn() },
+    _crashDiag: { log: vi.fn() },
+    performance: { now: () => now },
+    requestAnimationFrame: (_fn: () => void) => 1,
+    setTimeout: (_fn: () => void) => 1,
+    Blob: function Blob() {},
+    URL: {
+      createObjectURL: () => 'blob:yield',
+      revokeObjectURL: () => {},
+    },
+    Worker: function Worker(this: any) {
+      this.postMessage = () => {};
+    },
+    MobileDetection: {
+      isTouchDevice: () => true,
+    },
+    DEC_SYNC_STRIP_RE: /\x1b\[\?2026[hl]/g,
+    TERMINAL_CHUNK_SIZE: 32 * 1024,
+  });
+
+  const code = readFileSync(resolve(import.meta.dirname, '../src/web/public/terminal-ui.js'), 'utf8');
+  vm.runInContext(code, context, { filename: 'terminal-ui.js' });
+
+  const app = new (CodemanApp as any)();
+  return {
+    app,
+    setNow: (value: number) => {
+      now = value;
+    },
+  };
+}
+
+function createElementHarness() {
+  const listeners = new Map<string, (ev: any) => void>();
+  return {
+    element: {
+      addEventListener: vi.fn((type: string, listener: (ev: any) => void) => {
+        listeners.set(type, listener);
+      }),
+    },
+    dispatch(type: string, event: any) {
+      listeners.get(type)?.(event);
+    },
+  };
+}
+
+describe('terminal touch tap mouse guard', () => {
+  it('suppresses browser trusted compatibility mouse events during the tap window', () => {
+    const { app } = loadTerminalUiHarness();
+    const { element, dispatch } = createElementHarness();
+    app.terminal = { element };
+
+    app._installMobileTapMouseGuard();
+    app._suppressTrustedTapMouseEvents();
+
+    const event = {
+      isTrusted: true,
+      preventDefault: vi.fn(),
+      stopImmediatePropagation: vi.fn(),
+    };
+    dispatch('mousedown', event);
+
+    expect(event.preventDefault).toHaveBeenCalledOnce();
+    expect(event.stopImmediatePropagation).toHaveBeenCalledOnce();
+  });
+
+  it('allows the app synthetic mouse event through the tap window', () => {
+    const { app } = loadTerminalUiHarness();
+    const { element, dispatch } = createElementHarness();
+    app.terminal = { element };
+
+    app._installMobileTapMouseGuard();
+    app._suppressTrustedTapMouseEvents();
+
+    const event = {
+      isTrusted: false,
+      preventDefault: vi.fn(),
+      stopImmediatePropagation: vi.fn(),
+    };
+    dispatch('mousedown', event);
+
+    expect(event.preventDefault).not.toHaveBeenCalled();
+    expect(event.stopImmediatePropagation).not.toHaveBeenCalled();
+  });
+
+  it('allows trusted mouse events after the tap window expires', () => {
+    const { app, setNow } = loadTerminalUiHarness();
+    const { element, dispatch } = createElementHarness();
+    app.terminal = { element };
+
+    app._installMobileTapMouseGuard();
+    app._suppressTrustedTapMouseEvents();
+    setNow(2_000);
+
+    const event = {
+      isTrusted: true,
+      preventDefault: vi.fn(),
+      stopImmediatePropagation: vi.fn(),
+    };
+    dispatch('mousedown', event);
+
+    expect(event.preventDefault).not.toHaveBeenCalled();
+    expect(event.stopImmediatePropagation).not.toHaveBeenCalled();
+  });
+});