Interface IOverlayService

Namespace

Nalu

Assembly

Nalu.Maui.Scaffold.dll

MVVM overlay presentation: shows model-first popups and bottom sheets registered via AddOverlay<TModel, TView>(), mirroring the navigation engine's conventions — intents delivered to OnEnteringAsync(TIntent), ILeavingAware and IAsyncDisposable/IDisposable honored on close, one DI scope per presentation.

public interface IOverlayService

Remarks

Construction: the model is created via ActivatorUtilities against a provider serving IOverlayRef; the view likewise, with the model additionally resolvable — each constructor declares only what it needs (services, the ref, the model). Keep ONE public constructor per model/view: multi-constructor selection is not service-aware.

The returned task completes when the overlay CLOSES, whatever the path: with the result the model reported via CloseAsync(object?), or default on dismissal (scrim tap, pull-down, system back, navigation). Closing from OnEnteringAsync skips the presentation entirely — the task completes without ever showing the overlay.

Whenever the app is not scaffold-hosted — a non-scaffold navigation host, or a platform without scaffold hosting (Windows, Mac Catalyst) — every call is a graceful no-op completing immediately with default: shared page models can inject and call the service unconditionally.

Methods

ShowBottomSheetAsync<TModel>(object?, ScaffoldBottomSheetOptions?)

Shows a registered overlay model as a bottom sheet with no result; the task completes when it closes.

Task ShowBottomSheetAsync<TModel>(object? intent = null, ScaffoldBottomSheetOptions? options = null) where TModel : class

Parameters

intent object

Optional intent delivered to the model's OnEnteringAsync(TIntent); falls back to the parameterless OnEnteringAsync() when no matching overload exists.

options ScaffoldBottomSheetOptions

Call-site presentation overrides (each set property wins over the view's attached values).

Returns

Task

Type Parameters

TModel

The registered overlay model.

ShowBottomSheetAsync<TModel, TResult>(object?, ScaffoldBottomSheetOptions?)

Shows a registered overlay model as a bottom sheet and awaits its result.

Task<TResult?> ShowBottomSheetAsync<TModel, TResult>(object? intent = null, ScaffoldBottomSheetOptions? options = null) where TModel : class

Parameters

intent object

Optional intent delivered to the model's OnEnteringAsync(TIntent); falls back to the parameterless OnEnteringAsync() when no matching overload exists.

options ScaffoldBottomSheetOptions

Call-site presentation overrides (each set property wins over the view's attached values).

Returns

Task<TResult>

Type Parameters

TModel

The registered overlay model.

TResult

The result type the model reports via CloseAsync(object?).

ShowPopupAsync<TModel>(object?, ScaffoldPopupOptions?)

Shows a registered overlay model as a popup with no result; the task completes when it closes.

Task ShowPopupAsync<TModel>(object? intent = null, ScaffoldPopupOptions? options = null) where TModel : class

Parameters

intent object

Optional intent delivered to the model's OnEnteringAsync(TIntent); falls back to the parameterless OnEnteringAsync() when no matching overload exists.

options ScaffoldPopupOptions

Call-site presentation overrides (each set property wins over the view's attached values).

Returns

Task

Type Parameters

TModel

The registered overlay model.

ShowPopupAsync<TModel, TResult>(object?, ScaffoldPopupOptions?)

Shows a registered overlay model as a popup and awaits its result.

Task<TResult?> ShowPopupAsync<TModel, TResult>(object? intent = null, ScaffoldPopupOptions? options = null) where TModel : class

Parameters

intent object

Optional intent delivered to the model's OnEnteringAsync(TIntent); falls back to the parameterless OnEnteringAsync() when no matching overload exists.

options ScaffoldPopupOptions

Call-site presentation overrides (each set property wins over the view's attached values).

Returns

Task<TResult>

Type Parameters

TModel

The registered overlay model.

TResult

The result type the model reports via CloseAsync(object?).