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Material 3 Android Overlay Adapter

viewcompose-overlay-material3-android is the narrow Material presentation adapter for ViewCompose overlays. It supplies Material Components Snackbar and modal-bottom-sheet presenters to the neutral viewcompose-overlay-android transport. It does not own generic Android Dialog, PopupWindow, Toast, anchor positioning, nested render containers, or service-provider selection.

Artifact and stability​

dependencies {
    implementation("com.viewcompose:viewcompose-overlay-material3-android:0.1.0-alpha01")
}
  • Stability: Alpha.
  • API dependencies: UI Contract and UI Foundation because AndroidOverlayHost exposes their overlay contracts.
  • Implementation dependencies: the neutral Android overlay transport, Host Android, Android Renderer shape bridge, AppCompat, and Material Components.
  • Normal Material applications receive this artifact transitively from viewcompose-material3-android.

API quality: the Material AndroidOverlayHost remains a Q3 root-integration API. Its public attribution snapshot is diagnostic evidence, not a mutable presenter registry.

Explicit Material assembly​

com.viewcompose.overlay.material3.android.host.AndroidOverlayHost(rootView) composes:

  • neutral Android Dialog, PopupWindow, Toast, nested-session, and cleanup behavior;
  • Material Snackbar presentation and terminal callback mapping;
  • Material BottomSheetDialog presentation and behavior; and
  • the accepted 24dp dialog window inset used by the Material adapter.

The adapter registers no AndroidOverlayHostFactoryProvider. Material selection is explicit in setMaterial3UiContent, so merely placing this artifact on a One UI or neutral application's classpath cannot change its overlay behavior.

integrationAttribution reports the neutral transport separately from the Material presenter for each capability. Dialog and popup content keep the Material token/recipe snapshot captured at declaration. Snackbar and modal bottom sheet report their Material Components backends as Equivalent; Android Toast remains an explicit degraded platform fallback.

Material presenter behavior​

Material Snackbar maps action, timeout, swipe, replacement, and generic platform terminal events to the UI Foundation transient queue. An explicit framework dismissal reason wins over a later Material callback.

Material modal bottom sheet preserves its platform dialog and nested surface for same-key updates. It applies the complete Foundation-resolved container color, content role, logical shape, scrim, expansion policy, and exact-versus-platform-default navigation-bar treatment without moving session ownership into this adapter. Every changed same-key update reapplies that complete snapshot. Changing skipPartiallyExpanded from true to false clears the old Material skipCollapsed policy rather than retaining stale behavior.

Logical shapes are converted by the neutral Android Renderer bridge; this adapter does not contain Material-only shape interpretation. Restoring PlatformDefault also restores Android Q+ contrast enforcement after an exact color disabled it.

All root, window, presenter, callback, and cleanup work is confined to the Android main thread. The adapter must not outlive its root View's window.

The generated reference is available in the viewcompose-overlay-material3-android API tree.

Compatibility notes​

The initial alpha registered a whole Material host through ServiceLoader and also implemented generic Android overlay transport. The current hard cut removes that registration and moves all generic transport to the reactivated viewcompose-overlay-android coordinate. Custom hosts that need Material behavior must construct this adapter explicitly.