Ubisam-MobileGit/tasks/025-branch-detail-tabs.md

TASK-025: Tabbed branch detail screen (Files + History), repository row commit time, swipeable repository/favorites tabs, and live-testing follow-up fixes

Status: implemented; all required checks pass; device verification pending Owner: Claude Reviewer: Codex

Outcome

Three more live requests from the same testing session:

1. Tapping a branch/tag now opens one screen with two swipeable tabs — 파일 (Files, the code browser, default) and 히스토리 (History) — over the same ref, restoring file/folder browsing (removed from the UI by TASK-024) while keeping the direct-to-history behavior the human product owner asked for, by making history the second tab instead of the only destination.
2. Each repository row on the repository list now shows its last-commit time (reusing the existing updatedAtEpochMillis field and the shared formatInstant helper from TASK-024 — no new API data needed).
3. The repository list's 전체(All)/즐겨찾기(Favorites) tabs are now swipeable (swipe right from All → Favorites, swipe left from Favorites → All), not just tap-to-switch.

Plus seven more follow-up fixes/changes found or requested during the same live-testing pass on the same branch, kept in this task rather than split out since they're all small, tightly related touch-ups to screens this task already modifies or reuses:

4. Overlap bug fix: the narrow-layout (non-Z-Fold-unfolded) branch of CommitDetailScreen's BoxWithConstraints had Header(...) and its content as bare siblings instead of children of a Column, so BoxWithConstraints (which behaves like Box — it does not arrange multi-child branches vertically on its own) rendered them stacked on top of each other. Reported twice by the human product owner via screenshot before being root-caused; fixed by wrapping each branch's contents in Column(Modifier.fillMaxSize()) { ... }.
5. Status-bar padding fix: BranchDetailScreen's TabRow was jammed against the status bar because, unlike every other top-level screen in the app, it wasn't wrapped in its own Scaffold. Fixed with Modifier.statusBarsPadding() on the outer Column (not a nested Scaffold, to avoid double-padding since CodeBrowserScreen/HistoryScreen already have their own Scaffolds internally).
6. Diff horizontal-scroll fix, in two passes: DiffSideLine (in the History tab's file-diff view) originally had Modifier.fillMaxWidth().horizontalScroll(state) and no softWrap = false, so long lines wrapped instead of overflowing — nothing to scroll. First pass fixed that by removing fillMaxWidth() and adding softWrap = false, matching the already-working PatchText composable's modifier pattern — but that pattern shares one ScrollState across every row in the panel (so dragging any line moves them all together), and a single ScrollState's scroll bound is set from whichever row's layout pass ran most recently; with many differently-wide lines in the same list, that bound kept getting overwritten mid-drag, snapping the visible offset back and forth ("글자가 춤을 추네" — reported live, with a screenshot, after the first pass had already been installed). Second pass replaced the shared ScrollState with a hand-rolled scroll: one Modifier.scrollable(...) per row feeding a single shared offset value, clamped against one bound computed once up front (via TextMeasurer, from the longest line in the file) instead of recomputed per row, then applied to each row with a plain Modifier.offset { ... } — so no per-row layout pass can stomp on another row's bound anymore.
7. Loading-text simplification: the references-loading message on the repository screen previously interpolated the repository name into a longer sentence; simplified to a plain "로딩 중" per direct request, and the now-unused %1$s placeholder removed from repositories_references_loading.
8. In-app back buttons removed: every screen-header back button (CodeBrowserScreen's BrowserHeader, HistoryScreen's Header, NotificationsScreen's FilterTabs, WorkItemsScreen's ModeTabs and DetailHeader, RepositoryListScreen's ReferencesContent header) removed, since every screen already has a BackHandler wired to the system back gesture and the human product owner asked to rely on that instead. WorkItemsScreen's DetailHeader composable (which consisted only of a back button) removed entirely along with all 5 call sites. Now-unused history_back/notifications_back/workitems_back/codebrowser_back string resources removed; repositories_back kept, since it's a distinct recovery action on the references-error state's secondary button, not a header back button.
9. Pull-to-refresh replaces manual refresh buttons: RepositoryListScreen's RepositoryContent and ReferencesContent each had a manual "새로고침" OutlinedButton; both replaced with PullToRefreshBox (Material3, @OptIn(ExperimentalMaterial3Api::class)) wrapping their LazyColumns, so pulling down from the top refreshes instead.
10. Tab-swipe vs. code-scroll gesture conflict fixed: the Files/History HorizontalPager and the diff view's horizontal code scroll (item 6) are both horizontal gestures over the same screen; nested, they fought over every drag — reported live as visible "trembling" and, separately, source text intermittently scrolling out of view entirely. Root-caused (by the human product owner, from directly watching it happen) as the pager and the inner scroll both trying to consume the same drag. Fixed by disabling the pager's own swipe gesture (userScrollEnabled = false) whenever the currently-visible tab is showing horizontally-scrollable source text — a code file's contents on the Files tab, or a selected diff on the History tab — and re-enabling it everywhere else (folder listings, the commit list, a commit's changed-file list), so tab-swiping still works right up to the point actual code is on screen. Tapping a tab always still works regardless, since that's a direct animateScrollToPage call, not a gesture. Verified in both directions live via scripted adb shell input swipe (an earlier same-session test of this had looked like a regression, but was actually just a swipe fired in the wrong direction from the last page, which has nowhere further to go — not a real bug).

Scope

• Included: ui/navigation/Route.kt/RouteStackSaver.kt (Route.CodeBrowser/Route.History replaced by one Route.BranchDetail), new feature/branchdetail/BranchDetailScreen.kt, MainActivity.kt wiring, strings_branchdetail.xml, plus the follow-up touch-ups (items 4-10 above) to feature/branchdetail/BranchDetailScreen.kt (item 10), feature/history/HistoryScreen.kt, feature/codebrowser/CodeBrowserScreen.kt, feature/notifications/NotificationsScreen.kt, feature/workitems/WorkItemsScreen.kt, feature/repositories/RepositoryListScreen.kt, and their string resources.
• Excluded: No change to CodeBrowserViewModel/HistoryViewModel internals — both are reused exactly as they were, including their own internal drill-down (subfolder navigation, commit detail) and their own per-state BackHandlers. This screen only adds the TabRow + HorizontalPager chrome around them. No change to actual refresh/pagination/network logic — item 9 only changes the trigger UI, not what onRefresh does.

Design notes

• Both tabs' ViewModels (codeBrowserViewModel, historyViewModel) are opened together when Route.BranchDetail becomes current, and closed together when either tab's internal back-handling has nothing left to unwind (onCodeBrowserBack/onHistoryBack both close both ViewModels and pop the route) — a single shared exit point rather than two independently-tracked one.
• HorizontalPager's default beyondViewportPageCount (0) means only the currently visible tab is composed, so each tab's own internal BackHandlers never conflict with each other — the system back button always applies to whichever tab is actually on screen, with no extra coordination code needed.
• CodeBrowserScreen's existing "히스토리" header button is kept, repurposed to animate the pager to the History tab instead of pushing a route — a working existing affordance, not dead code.
• Route.CodeBrowser and Route.History are fully removed (not left dead), since Route.BranchDetail is now the only way either screen is reached.

Acceptance criteria

• Tapping a branch/tag opens Route.BranchDetail, defaulting to the Files tab.
• Files tab supports folder drill-down and reading file contents (the restored TASK-006 code browser, unmodified).
• Swiping left/right between tabs works (HorizontalPager); tapping a tab also works (TabRow).
• System back: within a subfolder/commit-detail, back unwinds that tab's own internal state first; only at each tab's own root does back exit the branch-detail screen entirely.
• RouteEncoding/RouteStackSaver round-trip Route.BranchDetail including a ref containing a slash, and fall back to Repositories on truncated/malformed persisted data.
• Commit-detail screen renders correctly (no overlapping content) in the narrow/folded layout.
• BranchDetailScreen's tab row sits below the status bar, not jammed against it.
• Diff view supports horizontal scroll on long lines (synced across before/after panels).
• References-loading message reads a plain "로딩 중".
• No in-app back buttons remain on any screen header; system back gesture still exits each screen/subview correctly.
• Pulling down from the top of the repository list or references list triggers a refresh; no manual refresh button remains.
• Build, unit tests, and lint pass.
• Full device confirmation of the tab UI, swipe gesture, back-button removal, and pull-to-refresh together in one pass.

Required checks

./gradlew assembleDebug
./gradlew testDebugUnitTest
./gradlew lintDebug

Evidence

• feature/branchdetail/BranchDetailScreen.kt (new): TabRow + HorizontalPager(pageCount = { 2 }), page 0 = CodeBrowserScreen, page 1 = HistoryScreen, both passed through unmodified with their full existing parameter lists.
• ui/navigation/Route.kt: CodeBrowser/History replaced by BranchDetail(owner, name, refKind, ref). RouteStackSaver.kt's RouteEncoding updated to match (TYPE_BRANCH_DETAIL replaces TYPE_CODE_BROWSER/TYPE_HISTORY).
• MainActivity.kt: onReferenceSelected now maps the tapped reference's ReferenceKind (branch/tag) to CodeReferenceKind and pushes one Route.BranchDetail, matching what previously only fed Route.CodeBrowser's refKind field — this mapping had been temporarily lost when TASK-024 redirected the tap straight to Route.History (which didn't need a ref kind); this task restores it.
• RouteEncodingTest.kt updated: code browser route round-trips and history route round-trips tests replaced by one branch detail route round-trips including a ref containing a slash test; the truncated-route and full-back-stack tests updated to match.
• HistoryScreen.kt's CommitDetailScreen: each BoxWithConstraints branch now wraps Header(...) + content in Column(Modifier.fillMaxSize()) { ... } instead of leaving them as bare siblings.
• BranchDetailScreen.kt: outer Column gained Modifier.statusBarsPadding().
• HistoryScreen.kt's DiffSideLine (first pass, superseded — see below): Modifier.horizontalScroll(horizontalScrollState).padding(...) with softWrap = false, no fillMaxWidth().
• HistoryScreen.kt's DiffSideLine/FileDiffView (second pass, current): shared ScrollState replaced by a manually-driven offset — rememberScrollableState { delta -> ... } updates one MutableFloatState clamped to [0, maxHorizontalOffsetPx], where maxHorizontalOffsetPx is computed once per selected file via rememberTextMeasurer().measure(...) against the longest line's character count (monospace, so any character stands in for the widest line's glyph width). Each row applies Modifier.scrollable(sharedScrollableState, Orientation.Horizontal) for gesture capture and Modifier.offset { IntOffset(-horizontalOffsetPx.value.roundToInt(), 0) } for rendering, wrapped in Box(Modifier.fillMaxWidth().clipToBounds()) since a plain offset (unlike horizontalScroll) doesn't clip overflow on its own.
• strings_repositories.xml: repositories_references_loading simplified to a fixed "로딩 중" string (no %1$s placeholder); call site in RepositoryListScreen.kt updated to match.
• Back buttons removed from CodeBrowserScreen.BrowserHeader, HistoryScreen.Header, NotificationsScreen.FilterTabs, WorkItemsScreen.ModeTabs; WorkItemsScreen.DetailHeader composable and its 5 call sites removed entirely; ReferencesContent's header back button removed. history_back/notifications_back/workitems_back/codebrowser_back string resources removed as now-unused.
• RepositoryListScreen.kt: RepositoryContent/ReferencesContent wrapped in PullToRefreshBox (@OptIn(ExperimentalMaterial3Api::class)), manual "새로고침" OutlinedButtons removed from both.
• ./gradlew compileDebugKotlin: BUILD SUCCESSFUL, both after the @OptIn(ExperimentalMaterial3Api::class) fix for PullToRefreshBox and again after the diff-scroll rewrite.
• ./gradlew assembleDebug testDebugUnitTest lintDebug (--rerun-tasks on the first full pass, incremental on the diff-scroll-rewrite follow-up): BUILD SUCCESSFUL both times, all unit tests passing, 0 lint errors.
• HistoryScreen.kt's diff-scroll rememberScrollableState (third pass): verified live (by directly swiping the device over adb) that the jitter-free scroll from the second pass ran in the wrong direction — dragging left revealed the start of the line instead of further along it, backwards from every other horizontally-scrollable surface on Android. Root cause: newOffset = horizontalOffsetPx + delta had the sign backwards for this gesture; fixed to newOffset = horizontalOffsetPx - delta, confirmed correct by the same live-swipe method (drag left now reveals later content, drag right returns toward the start, both panels stay in sync).
• BranchDetailScreen.kt: HorizontalPager gained userScrollEnabled = !currentPageShowsScrollableCode, where currentPageShowsScrollableCode checks codeBrowserState is CodeBrowserUiState.File && codeBrowserState.content is ContentClassification.Text on page 0, or historyState is HistoryUiState.CommitDetailContent && historyState.selectedFile != null on page 1 — both states were already being collected in MainActivity and passed into this screen, so no new state plumbing was needed.
• Live device: build installed over wireless adb (adb-RFCYA0RD1CZ-ztOzAA._adb-tls-connect._tcp, Galaxy Z Fold) five times across this task — initial batch, after the diff-scroll jitter fix, after the direction fix, and after the tab-swipe/code-scroll conflict fix. The last two were verified directly via scripted adb shell input swipe plus before/after screenshots (the human product owner requested this directly — "좌우 스크롤 해서 이상한걸 감지해볼래?" — rather than reporting a symptom first) instead of waiting on a live report; the human product owner then separately diagnosed the tab-swipe/scroll conflict's root cause from watching it happen and directed the fix. Human product owner asked to confirm the rest of the batch (tabs, overlap fix, status-bar padding, back-button removal, pull-to-refresh) together — result pending as of this commit.

Review findings

None yet — no Codex review pending (Codex retired, 2026-09-29).