Windows Browse: Show the current folder path and preserve the view on navigation failure #121

이전 전체 재설계의 합성 UI 제안입니다. 실제 Windows 앱 캡처가 아니며, 주변 메뉴나 breadcrumb·추가 조작 요소의 구현 승인을 뜻하지 않습니다. 이번에는 위의 축소 설계가 우선합니다.

Browse: show the current folder path and preserve the view on navigation failure

Scope decision: 2026-10-19. The user agreed to retain the existing parent/drive navigation and reduce #121 to two changes. This body proposes the detailed design. The current request authorizes updating the issue/design, not implementing, merging or releasing the app.

Coordination: #112. Preservation contracts: #110. Prerequisite #120 is complete.

Plain-language outcome

Keep the current way of navigating folders and drives. Add a small path line above Browse so the user knows which folder the list represents. If a destination cannot be opened, keep the previous view and explain why.

The image may still come from folder A while Browse shows folder B. The path line must identify B, not the image document's folder.

Already implemented: [..] first in real directories including drive/share roots; logical-drive choices such as [C:]/[D:]; mouse, Enter, Backspace and Alt+Up; existing UNC boundaries. These are regression contracts, not new work. The evidence is existing code, changelog v2.7.20/v2.7.23 and Gallery integration assertions; no new native run is claimed for this design update.

A. Read-only path line

Browse region only
┌─────────────────────────────────┐
│ D:\00\_temp                      │ New: current Browse folder
├─────────────────────────────────┤
│ [..]                            │ Existing parent item
│ [Travel photos]                 │
│ Thumbnails / file list           │
└─────────────────────────────────┘

At drive root: path D:\, first item [..]
At drive chooser: path Drives, items [C:\], [D:\], …

This is a layout explanation, not a native screenshot or a requirement to add a boxed card/title.

• One fixed path line above both compact list and grid, hidden with Browse. Do not change the image canvas, top menu or bottom status.
• Derive it from the successfully committed Browse directory, not document title or selected file. Explicitly distinguish uninitialized browsing from the actual logical-drive chooser.
• Show normal directory paths, roots such as D:\ and Drives for the chooser. Middle-elide long paths, prioritizing the drive/UNC prefix and current leaf; elide an oversized leaf only when necessary. Never shrink the font to fit. Preserve the exact full string.
• Hover exposes the full path. Keyboard focus exposes selectable/copyable full text using a read-only text presentation; screen readers receive the full value and Current folder name. This is not an editable address bar or clickable breadcrumb. Clicking/focusing does not navigate or open images.
• Reuse current Pretendard, theme, DPI and Windows text-size services; measure height from text plus padding. No new icon, link-blue treatment or heavy border.
• In the focused path text, Ctrl+A/Ctrl+C select/copy the path, not files. Esc returns focus to the list without navigation. Retain E, parent-navigation and other nonconflicting application shortcuts.

On successful navigation, path and items change together while the image remains unchanged. On failure, both remain at the previous folder. Root [..] shows Drives; successfully opening [D:] shows D:\ and its existing parent item.

B. Preserve state when navigation fails

• Missing/moved folders, access-denied targets and unavailable/disconnected drives must not replace the previous path, entries, selection, scroll or focus context.
• Do not close/reopen the active image or modify its pixels, zoom, pan, ROI or playback state to recover.
• For explicit failed navigation, use one standard error dialog through the existing message path. Include target, readable cause and next action; use Can't open folder in the current English UI, and retain the Windows code for unknown errors. Restore Browse focus after dismissal. No permanent error panel or new Retry button; reactivating the item retries.
• Background/watch refresh failures must not repeatedly open dialogs, empty the view or force navigation elsewhere. Recheck on the next explicit access.
• An accessible empty directory is a successful destination, with its normal [..] item.

Implementation boundary: prepare, then commit

The current Populate changes the old list/selection/cache state before directory enumeration is known to succeed. PathIsDirectory alone cannot handle access denial or deletion/disconnection after preflight.

1. Reuse NavigateTo/GoToParent/drive entry points; separate requested destination from committed browsing state.
2. Enumerate into a temporary result and capture the actual outcome/error. Distinguish an accessible empty directory from failure. A partially enumerated result with an error is not success.
3. Commit directory, path display and entries together only on success. Preserve existing ordering, filtering, parent items, child selection after going up, cache/generation and directory-watch behavior. A failed attempt must not invalidate all previous thumbnail work.
4. On failure leave the old snapshot untouched and report the cause. With no previous folder, retain the initial view. Never clear first and reconstruct the previous view as recovery.
5. Review other Populate callers: presentation switches, current-file synchronization and directory refresh. Preserve an existing snapshot on refresh failure. Document-open success is independent; the path line must match the actual Browse contents.
6. Review slow-device/UNC execution so preparation does not block UI for a long time. If preparation is asynchronous, use navigation request IDs, accept only the latest result, discard stale success/errors and stop publication after destruction. Keep previous contents until success. Do not add full-image reads or overload thumbnail decoding.

This is a small safety boundary plus a path display, not a replacement file browser/image loader.

Out of scope

Rebuilding existing [..]/drive/UNC navigation; an additional Up button; clickable breadcrumbs, address input, Ctrl+L, Back/Forward history, search/network discovery; folder-card/context/recycle/top-menu redesign; image transforms, RAW interpretation or autoplay; Comparator/Qt changes; version bump, merge, release tag or Store submission.

Small implementation/review steps and acceptance

Keep A and B evidence separate so A can be reviewed before B.

• A: consistent path in list/grid, independent of the active image folder.
• A: long Unicode/Korean/space-containing paths, UNC, narrow Browse and enlarged text remain discoverable; full text is available through keyboard, tooltip and accessibility.
• A: path text selection/copy does not select files or trigger image/navigation commands.
• B: missing/access-denied/not-ready/disconnected/mid-enumeration errors preserve previous directory, entries, selection, scroll and image, with one actionable explicit-failure message.
• B: accessible empty folders work; background refresh does not spam dialogs.
• Regression: D:\00_temp → D:\00 → D:\ → drives → D:\ works with mouse/keyboard in list/grid, preserving UNC boundaries and child selection after going up.
• Regression: compare document, displayed pixels, zoom, pan, ROI and playback before/after navigation/failure; retain E, Page Up/Down, thumbnail and GPU-recreation checks.
• If asynchronous: cover out-of-order completion, failure then success, closing the window and late errors after newer success.
• Verify the actual Windows Viewer in Light/Dark/high contrast and supported DPI/text-size cases; run relevant core tests/local builds and record evidence/limitations. Mockups do not count as native verification.

Use deterministic failure injection for permission/device races plus safely reproducible temporary native fixtures. Do not change permissions on the user's actual folders or forcibly disconnect working drives.

Agreed: reduced scope and unchanged navigation. Proposed for review: path-line interaction and error presentation above. Not done in this update: app implementation, new validation, merge or release. Keep the issue open. Start a focused branch from current origin/master when implementation is authorized, following AGENTS.md and #110. This issue takes precedence over controls illustrated in the earlier broader mockup.

Existing population/navigation implementation, existing root/drive/missing-path integration assertions.