tui-chat-bar — Workgraph live mirror

Metadata

Status	done
Assigned	`agent-917`
Agent identity	`f51439356729d112a6c404803d88015d5b44832c6c584c62b96732b63c2b0c7e`
Created	2026-04-28T20:16:18.339225070+00:00
Started	2026-04-28T20:17:59.772473296+00:00
Completed	2026-04-28T20:44:35.388011237+00:00
Tags	`eval-scheduled`
Eval score	0.78
└ blocking impact	0.85
└ completeness	0.82
└ constraint fidelity	0.70
└ coordination overhead	0.74
└ correctness	0.76
└ downstream usability	0.80
└ efficiency	0.77
└ intent fidelity	0.84
└ style adherence	0.85

Description

When the chat-tab bar runs out of horizontal room, hidden tabs become unreachable. With cap moving to 16 (separate task), this gets worse fast. Need a way to navigate beyond the visible slots.

What to build

Pagination or scrolling behavior on the chat bar when tab count > visible slots
Keyboard navigation: Ctrl+Tab / Ctrl+Shift+Tab to cycle, OR Ctrl+t then number, OR PgUp / PgDn on the bar — pick what fits ratatui idioms and what's already used elsewhere in the TUI
Visual indicator when there are off-screen tabs (e.g. ◀ chat-3 chat-4 chat-5 ▶ arrows or a '+N more' badge)
Click-drag is a stretch goal — only if the existing TUI already handles mouse drag elsewhere; don't introduce a whole mouse-event subsystem just for this

Out of scope

Reordering tabs (separate UX feature)
Closing tabs (already shipped — tui-cannot-retire / implement-tui-tabs)
Renaming tabs

Validation

With cap=16 and 16 chats spawned at narrow terminal width, every tab is reachable via keyboard
Visual indicator clearly shows when tabs are off-screen
No regression at wide terminal widths (all-visible case looks identical to today)
Manual smoke at terminal widths 80, 120, 200 — assert no clipping, no garbled output
cargo build + cargo test pass

## Description

When the chat-tab bar runs out of horizontal room, hidden tabs become unreachable. With cap moving to 16 (separate task), this gets worse fast. Need a way to navigate beyond the visible slots.

### What to build
- Pagination or scrolling behavior on the chat bar when tab count > visible slots
- Keyboard navigation: `Ctrl+Tab` / `Ctrl+Shift+Tab` to cycle, OR `Ctrl+t` then number, OR `PgUp` / `PgDn` on the bar — pick what fits ratatui idioms and what's already used elsewhere in the TUI
- Visual indicator when there are off-screen tabs (e.g. `◀ chat-3 chat-4 chat-5 ▶` arrows or a '+N more' badge)
- Click-drag is a stretch goal — only if the existing TUI already handles mouse drag elsewhere; don't introduce a whole mouse-event subsystem just for this

### Out of scope
- Reordering tabs (separate UX feature)
- Closing tabs (already shipped — `tui-cannot-retire` / `implement-tui-tabs`)
- Renaming tabs

## Validation

- [ ] With cap=16 and 16 chats spawned at narrow terminal width, every tab is reachable via keyboard
- [ ] Visual indicator clearly shows when tabs are off-screen
- [ ] No regression at wide terminal widths (all-visible case looks identical to today)
- [ ] Manual smoke at terminal widths 80, 120, 200 — assert no clipping, no garbled output
- [ ] cargo build + cargo test pass

Depends on

done .assign-tui-chat-bar

Required by

(none)

Log

2026-04-28T20:16:18.332800524+00:00 Task paused
2026-04-28T20:17:34.835023720+00:00 Task published
2026-04-28T20:17:58.671585832+00:00 Lightweight assignment: agent=Careful Programmer (f5143935), exec_mode=full, context_scope=task, reason=TUI feature implementation with keyboard navigation and multi-width regression testing matches the Programmer role; Careful tradeoff appropriate for correctness-sensitive UI work.
2026-04-28T20:17:59.772476552+00:00 Spawned by coordinator --executor claude --model opus
2026-04-28T20:18:30.776112178+00:00 Starting work — inspecting current TUI chat bar implementation
2026-04-28T20:42:07.183313630+00:00 Implementation complete: - Added chat_tab_scroll_offset to VizApp state with auto-scroll-to-active in renderer - Added compute_chat_bar_layout helper with 9 unit tests covering offset/arrow logic - Renderer draws ◀ (cyan) / ▶ (cyan) arrows when tabs are off-screen - Click handlers on arrows scroll bar by 1 (via VizApp::scroll_chat_tabs) - Existing Ctrl+Tab/Ctrl+Shift+Tab cycling + Alt+1..9 hotkeys now keep active tab visible (auto-scroll) - Added integration tests covering 16-chat narrow-width scenario and cycling - All 12 new tests pass; 3072/3079 binary tests pass (7 failing tests are pre-existing on main)
2026-04-28T20:44:18.389564159+00:00 Committed: 3cc7a1e13 — pushed to remote
2026-04-28T20:44:35.388024562+00:00 Task pending eval (agent reported done; awaiting `.evaluate-*` to score)
2026-04-28T20:46:58.301324828+00:00 PendingEval → Done (evaluator passed; downstream unblocks)