[zarv1k]

Summary

On touch devices a finger could not scroll full-screen apps — Claude Code, vim, less, htop — while a mouse wheel could. Two separate causes:

1. Mouse reporting / alternate screen. These apps run on the alternate screen, usually with mouse tracking on. xterm.js skips its own touch handling entirely while mouse events are active (if (this.coreMouseService.areMouseEventsActive) return; in its touchstart/touchmove listeners), and the alternate buffer has no scrollback for a viewport scroll to move anyway. Such apps scroll themselves when the terminal forwards the wheel.

   New src/touch.ts: while the app owns scrolling (terminal.modes.mouseTrackingMode !== 'none' or the alternate buffer is active), a vertical drag is turned into WheelEvents on .xterm-screen. xterm then handles them exactly like a real wheel — SGR 64/65 with mouse reporting, arrow keys without it — and a flick keeps gliding briefly after the finger lifts. A plain shell on the normal buffer is left to xterm's own touch scrolling.

2. Native text selection on iOS. CloudCLI's mobile stylesheet sets .xterm, .xterm .xterm-viewport { user-select: text !important } (for the built-in Shell's tap-hold selection). That applies to the plugin's terminals too, and on iOS it lets WebKit claim a finger drag as native text selection — after which touchmove never reaches the terminal at all. The plugin's stylesheet now restores xterm's own user-select: none for .wt-root .xterm.

Testing

• npm run typecheck and npm run build pass.
• Headless Chromium with touch emulation (CDP touch events):
  • alternate screen + SGR mouse: swiping up/down sends ESC[<65;… / ESC[<64;… reports, with more arriving during the glide; a slow drag that parks before lifting does not glide;
  • alternate screen without mouse: swiping sends ESC[B / ESC[A;
  • normal buffer with scrollback: xterm scrolls the viewport itself and nothing is sent to the PTY.
• Checked on an iPhone (installed PWA): scrolling works in Claude Code, less and vim, and in a plain shell's scrollback.
• npm test: resize reaches the PTY and a dropped connection keeps the shell alive… fail on unmodified main too in my environment (Debian 13, Node 24). This change only touches the frontend.