# TASK-053: Code viewer: full screen, search, outline, Visual Studio colors

Status: implemented; required checks pass; not yet confirmed on a device
Owner: Claude
Reviewer: human product owner

## Outcome

Reading code was what the product owner was most concerned about on a phone. The team reads C#
and C++, in Visual Studio. A file now opens full screen, outside the Files/Commit pager, with the
tools for getting to the part that matters: search within the file, an outline, a strip that says
which method the top line is in, a font size, and wrapping on by default. Colors follow Visual
Studio's defaults; the background and plain text follow the app theme.

## Scope

- Included: `CodeViewerScreen`, `CodePane` (lazily composed lines), `SymbolOutline`, `CodeSearch`, type /
  method / control-keyword coloring in `SyntaxHighlighter`, the code settings in `AppSettingsStore`,
  a compact landscape layout, and the unified diff of `FileDiffScreen` on a narrow window.
- Excluded: code folding; blame; a real parser. Multi-line strings are still colored only on the line they
  start on.

## Writable paths

- `app/src/main/java/com/ubisam/ubgitea/feature/codebrowser/`
- `app/src/main/java/com/ubisam/ubgitea/feature/branchdetail/`
- `app/src/main/java/com/ubisam/ubgitea/feature/history/`
- `app/src/main/java/com/ubisam/ubgitea/domain/history/UnifiedDiffParser.kt`
- `app/src/main/java/com/ubisam/ubgitea/core/settings/AppSettingsStore.kt`

## Acceptance criteria

- [x] A file opens full screen with a back button; the tabs and the app navigation step aside.
- [x] Wrapping is on by default; a wrapped line continues indented past the line's own indentation.
- [x] With wrapping off, the whole pane scrolls sideways together, not line by line.
- [x] Search highlights every match, starts from what is on screen, and moves to the next and previous match.
- [x] The outline lists namespaces, types, methods and fields for C#, C++, Java and Kotlin; a line number can be entered for any file.
- [x] Comments and string literals do not confuse the outline.
- [x] Word wrap and font size are remembered.
- [x] Lines are composed lazily, so a long file costs only what is on screen.
- [x] In landscape the chrome is one row.
- [x] A diff marks added and removed lines with + and − as well as color, and can jump between changes and files.
- [x] Build, unit tests and lint pass.
- [ ] Confirmed on the human product owner's device (phone and unfolded Z Fold).

## Security and privacy

No additional concerns. File content is shown, never logged or stored.

## Required checks

```text
./gradlew compileDebugKotlin compileDebugUnitTestKotlin testDebugUnitTest assembleDebug lintDebug
```

## Evidence

Recorded on 2026-09-28 in the worktree `awesome-pascal-3f2ada`, with Android Studio's bundled JDK (`D:\AndroidStudio\jbr`, OpenJDK 21). TASK-050 to TASK-054 were built together and checked together:

- `./gradlew compileDebugKotlin compileDebugUnitTestKotlin testDebugUnitTest assembleDebug lintDebug` -- passed.
- Unit tests: 409 in 45 suites, 0 failures, 0 errors (289 before this work).
- Lint: 0 errors, 55 warnings (dependency updates, unused resources, KTX suggestions).
- Emulator (API 36, `sdk_gphone64_x86_64`): the debug APK installs and launches without a crash and shows the sign-in screen with the logo and the new palette. Nothing past sign-in could be reached: that needs a company account.
- Not done: any check on a physical device. None was visible to `adb` during this work.
- New and extended tests: `SyntaxHighlighterTest` (34), `SymbolOutlineTest` (11), `CodeSearchTest` (25), `UnifiedDiffParserTest` (10), `FileDiffChangesTest` (4).
- Unit tests were written by a delegated worker from `handoff/2026-09-28_unit-tests-redesign.md`; the full run above was repeated here afterwards.

## Known limitations

- The outline recognizes declarations by their shape on the line they start on. It is right for code written the usual way and can miss a declaration written unusually or produced by a macro.
- Type and method coloring is by naming convention, not by resolving symbols: a PascalCase property after a dot is left plain, a PascalCase local would be colored as a type.
- Two light-theme colors are darker than Visual Studio's (type, comment) because the originals fall below 4.5:1 on white at code size.
- Sideways scrolling, text selection across lazily composed lines and the bottom sheet could not be exercised without a device.

## Review findings

None yet.