[juliusmarminge]

Problem

Typing in the composer, pressing Cmd/Ctrl+Alt+B to open the right panel (focus moves into it) and pressing it again to close leaves focus on the right panel's toggle button, so you have to click back into the composer to keep typing. Reproduced on main e455200077 in the web app with an empty panel and with a Terminal surface: after the close, document.activeElement is BUTTON "Toggle right panel".

Change

PreviewPanelShell remembers the element focus entered the panel from, through React onFocus/onBlur on the host. React focus events also see content that focuses itself while mounting, which a terminal surface does from its ref. A move through a menu portalled from the panel counts as inside the panel and keeps the origin. When the panel collapses or unmounts while it holds focus, focus goes back to that element with preventScroll. Otherwise it falls back to the panel toggle as before (https://git.cafe/pingdotgg/t3code/pulls/14786). The remembered element is cleared on collapse, so each open records its own.

A new canReturnFocusTo in workspaceFocus.ts decides whether that element can take focus back. The element must still be in a visible workspace area, which a drawer animating closed has already left, and it must be in view in its scrolling list, the same rule F6 uses, so the timeline never scrolls back to an old control. Focus already outside the panel is never moved. A panel opened by clicking the toggle still returns focus to the toggle.

Scope and approval

Fixes #32538

Verification

• vp test run apps/web/src/components/preview/PreviewPanelShell.browser.test.tsx: 8 passed. Against main's PreviewPanelShell.tsx and workspaceFocus.ts, 5 fail with focus on the toggle (collapse, unmount, content that focuses itself on mount, focus through a portalled menu, an origin from an earlier open); the 3 fallback guards pass on both.
• vp run check:changed on the head: format, lint, knip, typecheck, tests and React compiler pass.
• Two independent review rounds found no defects.

Evidence

Real app on both sides: before ac5e48c612 (merge-base), after c5c4a2170e (the head 215cda1806 only adds a merge of main), each with its own server and a fresh database seeded with synthetic data and the free Replay provider. Web: Chromium 157, 1280×800, DPR 2, no emulation, 100% font scale. Desktop: Electron 44 on Linux (Xvfb), 1280×800, DPR 1, real OS Ctrl+Alt+B. An on-screen overlay prints document.activeElement; recordings end by typing xyz to show where it lands (the Pull Requests row skips typing so search results stay loaded). Diff0 = zero threshold, amplified; DiffT = 8/255 per channel.

Row	Before	After	Diff0	DiffT	Recordings
Empty panel, composer → Ctrl+Alt+B → Ctrl+Alt+B → type 1280×800 dark	ac5e48c612	c5c4a2170e	ac5e48c612 → c5c4a2170e	ac5e48c612 → c5c4a2170e	before · after
Terminal surface autofocus, no animation 1280×800 light	ac5e48c612	c5c4a2170e	ac5e48c612 → c5c4a2170e	ac5e48c612 → c5c4a2170e	before · after
Pull Requests page right panel 1280×800 dark	ac5e48c612	c5c4a2170e	ac5e48c612 → c5c4a2170e	ac5e48c612 → c5c4a2170e	before · after
Linux desktop app, 400 ms animation 1280×800 dark	ac5e48c612	c5c4a2170e	ac5e48c612 → c5c4a2170e	ac5e48c612 → c5c4a2170e	before · after
Desktop Browser surface, focus in URL bar 1280×800 dark	ac5e48c612	c5c4a2170e	ac5e48c612 → c5c4a2170e	ac5e48c612 → c5c4a2170e	before · after

Before ends on "Toggle right panel" in every row above; after ends on the element focus came from (composer, or the Pull Requests search field). All 22 rows of the fixture matrix (animated close and rapid reopen, opened from the toggle, pointer close, focus already outside, stale origins, portalled menus, overflowing tabs and resizing, maximized, timeline and terminal-drawer origins, scrolled-out origin, medium and compact sheets, a labelled component harness for invalid origins and guarded unmount) are in the full evidence index, with driver and seed scripts.

What else changed, besides where focus lands: focus rings and tooltips follow the new focus target, the overlay text differs, and relative timestamps in the synthetic sidebar differ. Two behaviours are the same on both sides and come from main: closing the panel reflows the timeline (scrollTop 966 → 1010 → 966 on both; focus return adds no scroll), and when the terminal drawer closes in the same step, ChatView's existing drawer-close effect moves focus from the toggle to the composer. With focus inside a native Browser page, both sides end on the composer.

Not run on macOS (no macOS host); the diff has no platform-specific code, and the desktop rows ran on Linux Electron.

AI-assisted; verified with the tests and tools listed above.

[macroscopeapp]

Approvability

Verdict: Approved at 75be918

Macroscope's review found this PR approvable — Closing the right panel restores focus to its prior workspace control when that control remains visible and reachable, otherwise falling back to the panel toggle. The change is limited to browser focus handling and carries no obvious material risk.

No code changes detected at 215cda1. Prior analysis still applies.

^{You can add or adjust custom eligibility rules. Learn more.}

[coderabbitai]

No actionable comments were generated in the recent review.

Walkthrough

PreviewPanelShell now restores focus to the eligible element that preceded panel focus when the panel collapses or unmounts. It falls back to the panel toggle when that element cannot receive focus. Workspace focus checks and browser tests cover visibility, scrolling, drawer state, and focus-origin cases.

Changes: Panel focus restoration

Layer / File(s)	Summary
Focus origin restoration and validation apps/web/src/components/preview/PreviewPanelShell.tsx, apps/web/src/lib/workspaceFocus.ts, apps/web/src/components/preview/PreviewPanelShell.browser.test.tsx	PreviewPanelShell records the focus origin and returns focus there when it remains eligible. Otherwise, it uses the panel toggle. Browser tests cover collapse, unmount, and fallback scenarios.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Bug fix · Severity of issue fixed: Low

Possibly related issues

• pingdotgg/t3code#32532 reports the same right-panel focus restoration behavior addressed here.

Possibly related PRs

• pingdotgg/t3code#24818: Changes right-panel focus restoration on unmount and collapse.
• pingdotgg/t3code#19669: Adds workspace-area focus management and recovery when the right panel closes.

Suggested reviewers: t3dotgg

Merge Risk: Minimal · up to 75be9

The focus-restoration change is ready to merge after normal checks.

Pre-merge checks: 4

Check name	Status	Explanation
Title check		The title clearly describes the focus restoration change.
Linked Issues check		[ #32538 ] PreviewPanelShell records the focus origin and restores it on collapse or unmount when the target is eligible. It falls back to the toggle, including when the toggle opened the panel. Brows…
Out of Scope Changes check		[ #32538 ] The focus restoration, workspace visibility checks, and browser tests support the right-panel focus fix. The summary shows no unrelated changes.
Description check		The description covers the problem, change, linked issue, focused verification, and UI evidence. It is mostly complete. It does not state whether the linked issue has maintainer approval, and the AI-a…

Full details: Linked Issues check

Explanation

[ #32538 ] PreviewPanelShell records the focus origin and restores it on collapse or unmount when the target is eligible. It falls back to the toggle, including when the toggle opened the panel. Browser tests cover the composer, toggle, mounting focus, and portalled menus.

Full details: Description check

Explanation

The description covers the problem, change, linked issue, focused verification, and UI evidence. It is mostly complete. It does not state whether the linked issue has maintainer approval, and the AI-assistance note omits the model and harness.

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Recent review info

Run configuration

• Source mode: Auto
• Repository: pingdotgg/t3code
• Branch: fix/issue-32538
• File: .coderabbit.config.ts
• Commit: 75be918
• Layers: Repository TS config
• Review profile: CHILL
• Plan: Team
• Run ID: 1526fe7d-a415-4207-9e99-0c6f309ec331

Commits

Reviewing files that changed from the base of the PR and between 25bf84a and 75be918.

Files selected for processing: 3

• apps/web/src/components/preview/PreviewPanelShell.browser.test.tsx
• apps/web/src/components/preview/PreviewPanelShell.tsx
• apps/web/src/lib/workspaceFocus.ts

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