System bars

System bars are the persistent chrome of the AAOS experience: navigation affordances, app entry points, and system-level actions that frame application content.

MVP implementable spec: specs/system-bar.md (Views-first). This page is the overview; the spec is the contract.

Purpose

• Provide consistent wayfinding across OEM launchers and system UI.
• Remain usable under driving restrictions with large targets.
• Host OEM brand marks via tokens without custom forks.

Typical contents

Element	Notes
Home / map / app grid entry	Core navigation
HVAC peek / shortcut	May deep-link to HVAC
Media mini controls	Optional; see media
Notifications shade entry	Restriction-aware
OEM Quick controls	Extension slots

Exact layout is OEM-specific; Cabin standardizes slots, sizes, and compliance behavior.

States

• Default / scrolled (if content influences chrome)
• Driving-restricted (hide or substitute dense entries)
• Night / day schemes
• Focused (rotary)

Compliance

Concern	Rule
Driving	Limit entries that open setup/keyboard-heavy flows (driving)
UX	Min touch targets for all tappable slots (ux)
Safety class	Convenience chrome; do not bury safety controls exclusively here
Glance	Icons + short labels; stable positions

Token dependencies

• cabin.component.systemBar.height
• cabin.component.systemBar.iconSize
• cabin.color.semantic.surface / onSurface
• cabin.size.touch.minimum

Planned Compose API

// Planned — often used in app-level mock system UI / embedded chrome
@Composable
fun CabinSystemBar(
    slots: CabinSystemBarSlots,
    compliance: CabinCompliance = LocalCabinCompliance.current,
    modifier: Modifier = Modifier,
)

Planned Views API

<!-- Planned -->
<dev.decoupled.cabin.views.CabinSystemBarView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:cabinSlots="@xml/oem_system_bar_slots" />

System UI integrations typically prefer the Views path.

Parity notes

Slot model and restriction substitution must match. Visual height and icon sizes resolve from the same tokens.

Acceptance criteria

• Slot configuration without core fork
• Driving substitutes applied
• Touch minima enforced
• Day/night correct
• Dual-stack parity for shared apps / previews

Related

• Status bars
• Extension model
• Views platform