# TASK-059: From a function in the header to its definition in the source

Status: implemented; required checks pass; installed on the product owner's Z Fold7, awaiting their confirmation
Owner: Claude
Reviewer: human product owner

## Outcome

The human product owner confirmed the outline now appears for their C++ files (TASK-058) and asked
whether choosing a function in a `.h` could go to where it is written in the `.cpp`.

## Scope

- Included: in the outline (the side pane and the outline sheet), every function of a file that
  has a counterpart carries a button named after the counterpart's extension (`.cpp ›` in a
  header, `.h ›` in a source file). It opens the counterpart at the function of the same name.
  Choosing the row itself still goes to the function in the file being read.
- Excluded:
  - Tapping a function's name in the code itself.
  - Side by side: the two panes already move to the same function together, so no button there.
  - Telling overloads apart: the first function of that name is the one opened.

## Writable paths

- `app/src/main/java/com/ubisam/ubgitea/feature/codebrowser/CodeViewerScreen.kt`
- `tasks/`, `docs/`

## Acceptance criteria

- [x] The button appears only on functions, and only when the file has a counterpart that is not
      already beside it.
- [x] The drawer or sheet closes and the counterpart opens at the function.
- [x] A function with no definition in the counterpart (inline, pure virtual) opens the counterpart
      at its top rather than failing.

## Security and privacy

No additional concerns.

## Required checks

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

## Evidence

- Required checks pass: 435 unit tests, 0 failures; lint 0 errors. No test was added: the change
  is wiring in the screen, and the lookup it uses (`findSymbolNamed`, `openSibling` with a symbol)
  was already covered.
- Installed on the SM-F966N over wireless `adb`. Not seen working on a screen by the implementer.

## Review findings

None yet.