* fix(mobile): passthrough TUI rendering + touch-scroll
Two related mobile-UI fixes for cli_passthrough sessions, both
filed in #1031.
1. task-center-panel.tsx: align isPassthroughMode with the rest
of the codebase by checking session.is_passthrough first. The
memo previously only consulted agent_profile_snapshot.cli_passthrough,
which can be undefined in the Redux store on re-mount (the snapshot
isn't always present on the leaner session-list responses). When
that happened on mobile, the chat panel rendered the persisted-
messages TaskChatPanel fallback instead of the live PassthroughTerminal.
Desktop was immune because dockview-desktop-layout.tsx already uses
the session.is_passthrough field directly. is_passthrough is the
source of truth used by manager_startup.go's StartAgentProcess
routing — keeping the frontend consistent with that invariant.
2. passthrough-terminal.tsx: wire touch-drag scrolling on the xterm
viewport. xterm.js handles mouse wheel natively but not touch
gestures, so swiping inside the terminal on mobile bubbled up
and scrolled the page instead of the terminal scrollback —
effectively making everything that scrolled off-screen unreachable
on mobile. The new hook attaches touchstart/touchmove/touchend
handlers that map vertical drag delta to term.scrollLines(),
gated on (pointer: coarse) so desktop xterm behaviour stays
identical. Row-height comes from xterm's internal render dimensions
with a measured fallback (xterm 5.x layout) and a 16px constant
fallback if both fail.
Closes#1031
* fix(mobile): also fix useSessionLayoutState's isPassthroughMode + tighten touch-handling
Three follow-on fixes after Dan's mobile QA surfaced more cases:
1. apps/web/hooks/use-session-layout-state.ts — the mobile layout actually
uses THIS hook's isPassthroughMode memo (not the one in
task-center-panel.tsx that I previously fixed). It had the identical
snapshot-only bug. Aligned with the same is_passthrough-first priority.
2. apps/web/components/task/passthrough-terminal.tsx — always preventDefault
on touchmove (was only doing so when the row-delta calculation rounded
to non-zero, so sub-row drags slipped through to parent scroll). Added
touch-action: none + overscroll-behavior: contain inline on the terminal
element so the browser never claims the gesture.
3. apps/web/app/globals.css — overscroll-behavior: none on body to block
pull-to-refresh. iOS Safari ignores this in some configurations but
blocking it where possible reduces the page-reload race that was
triggering the stuck-on-loading-messages state.
* fix(mobile): trim PR to minimum required changes
After QA showed the user-visible mobile bug is fully addressed by the
useSessionLayoutState memo fix alone, revert the parallel changes to
the desktop hook (task-center-panel.tsx's useSessionApprove) and the
body-level overscroll-behavior — neither was required for the
reported bug, and Dan asked for the smallest possible diff.
Remaining changes:
- apps/web/hooks/use-session-layout-state.ts — actual mobile fix
- apps/web/components/task/passthrough-terminal.tsx — touch-scroll feature
* fix(mobile): tighten isPassthroughMode + drop terminal touch-scroll from this PR
Adversarial-review feedback applied:
- Change `is_passthrough === true` to `!== undefined` so an explicit
server-side false isn't overridden by a stale snapshot.
- Comment now cites the specific WS handler quirk in
ws/handlers/agent-session.ts where snapshot writes are truthy-guarded
but is_passthrough writes are !== undefined-guarded — that's the
concrete path where partial events land one without the other.
Dropped: the useMobileTouchScroll hook. Terminal scroll on mobile is a
separate feature that deserves its own discussion (xterm renders the
canvas above the scrollable viewport so native scroll doesn't reach the
viewport; the right fix likely lives in xterm itself or a small
event-redirect addon). Keeping this PR scoped to the rendering bug.
* fix(mobile): add minimal touch-scroll fallback for xterm viewport
xterm.js renders .xterm-screen (canvas) above .xterm-viewport, so iOS /
Android native scroll on the viewport never sees the touches and the
terminal is unscrollable on mobile.
useTouchScrollFallback wires touchstart/touchmove/touchend to
Terminal.scrollLines via an accumulated fractional-row delta. No
inertia — the proper fix is upstream in xterm-js. Gated on
(pointer: coarse) so desktop xterm behaviour is unchanged.
Sets touch-action: none + overscroll-behavior: contain inline on the
terminal element so the browser doesn't claim the gesture for
pull-to-refresh.
* fix(mobile): inertia decay on touch-scroll release for native-scroll feel
* fix(mobile): address adversarial review of touch-scroll hook
- Read xterm from ref inside each handler so renderer recreate doesn't
strand the handlers on a stale Terminal instance (React refs are
stable so dep array doesn't catch .current swaps).
- Drop the internal _core._renderService private-API path for row
height in favor of public term.rows + measured element height. The
internal path was API-unstable across xterm majors.
- Velocity window 80ms → 50ms so a direction reversal at the tail of
the gesture is the release velocity, not averaged against the early
motion.
- Reset pendingRows fractional accumulator on direction reversal — was
causing perceptible stickiness when reversing from slow-up to fast-down.
- Style restoration now uses removeProperty when the inline style was
never set, rather than leaking an empty string in its place.
* fix(mobile): revert touch-scroll hook from this PR — separate concern
After several iterations the touch-scroll fallback kept surfacing new
issues (iOS pull-to-refresh leaking through preventDefault, scroll
direction reversal edge cases) that suggest a more involved upstream
discussion is needed about whether to ship a workaround in
PassthroughTerminal at all vs fixing xterm.js's mobile story upstream.
Splitting that work out so this PR can land the rendering bug fix
cleanly. Will file a separate issue for the touch-scroll work with
the diagnosis + alternatives we explored.
* fix(mobile): honor is_passthrough when snapshot missing
---------
Co-authored-by: Carlos Florêncio <carlosmflorencio@gmail.com>
Daniel Brown