agent-device refuses to tap an on-screen TopAppBar action above a scrolling Column

A Material3 TopAppBar action button (e.g. a navigationIcon back arrow, or an actions icon) is rejected by click/press with:

Selector id=header-action resolved to an off-screen element and is not safe to click

…even though the button is plainly on-screen — uiautomator dump reports it inside the display, and a raw adb shell input tap on the same point activates it.

The trigger is the idiomatic Android layout Scaffold { topBar = TopAppBar{…} } { Column(Modifier.verticalScroll(…)) {…} }. snapshot -i models the whole screen as the scrolling Column ([scroll-area] [scrollable]) and folds the app bar into content above scroll-area hidden, so the off-screen guard treats the app-bar icons as outside the scroll viewport.

Environment

• agent-device 0.20.0 (also reproduces on 0.19.3)
• Android emulator, API 35 (Pixel 8), 1080×2400
• Jetpack Compose BOM 2026.06.01, Material3, androidx.activity 1.13.0, compileSdk 36 / targetSdk 35
• Kotlin 2.4.0, AGP 8.13.2 (the bug is layout-structural, not version-specific)

Reproduce

./repro.sh        # builds, installs, drives agent-device, asserts the mismatch

Requires one running Android emulator/device, the Android SDK, and Node (for npx agent-device).

Observed

### ground truth — header-action IS on-screen
screen 1080x2400
header-action bounds: [944,154][1070,280]      # top-right, well inside the display

### agent-device snapshot -i
@e1 [scroll-area] [scrollable]
  [content above scroll-area hidden]           # <-- the TopAppBar is folded in here
  [content below scroll-area hidden]

### click a content row (inside the scroll area)
Tapped id=row-3 (540, 668)                      # works

### click the TopAppBar action
Error (COMMAND_FAILED): Selector id=header-action resolved to an off-screen element and is not safe to click

### raw `adb shell input tap 1007 217` (center of header-action)
text="last tap: header-action"                  # the app registers it fine — not an app bug

Expected

click id=header-action should tap the button (as the raw tap and uiautomator confirm it is on-screen and hittable), the same way it taps content rows.

Minimal trigger (verified by A/B)

The screen is a bare ComponentActivity (no Nav3, no ViewModel — see MainActivity.kt):

Scaffold(
    topBar = { TopAppBar(actions = { IconButton(Modifier.testTag("header-action")) { … } }) }
) { padding ->
    Column(Modifier.fillMaxSize().padding(padding).verticalScroll(rememberScrollState())) { … }
}

• Column(Modifier.verticalScroll(...)) content → snapshot -i reports [scroll-area] + content above scroll-area hidden, and click id=header-action is refused as off-screen.
• Swap that one line for a LazyColumn → snapshot -i lists the rows flat (no "content above" folding) and the same header tap succeeds.

Not required to reproduce: Nav3 / NavDisplay, isTraversalGroup/paneTitle, a collapsing LargeTopAppBar. A plain TopAppBar above a verticalScroll Column is enough. The repro uses enableEdgeToEdge() (the modern targetSdk 35 default); whether that is required was not tested.

Why it matters

"TopAppBar above a scrolling content column" is one of the most common Android screen shapes, and a top-bar back/overflow/action icon is often the only way to leave or act on a screen. Under this layout those actions can't be driven by selector/@ref, and the only workaround is a raw coordinate tap (which defeats self-locating, resolution-independent flows).

Likely related

• #1075 — introduced "refuse off-screen selector taps" (the guard raising this message).
• #1366 / #1374 — open work on the off-screen-rejection guard (recovery in scrollable forms). This report is a different facet: a non-scrolled app-bar action, above the scroll area, being classified as hidden/off-screen.