Struct DropdownView 

pub struct DropdownView<State: 'static> { /* private fields */ }

A declarative dropdown: a dropdown_panel inside crate::overlay::anchored. See dropdown.

The host is composed fresh in each pass from the props below rather than retained: AnchoredOverlayView type-erases its content at construction, so there is no way to reach back into the panel and re-set one of its own props once it is inside — the same shape crate::menu::MenuView takes.

Implementations

impl<State: 'static> DropdownView<State>

pub fn anchor(self, anchor: &OverlayAnchor) -> Self

Anchor the panel to the rect anchor carries — the same cell the dropdown_field writes, which is also what width-matches the panel to the field.

pub fn selected(self, selected: Vec<String>) -> Self

Hand the panel the app-confirmed selection (option values).

pub fn multi(self, multi: bool) -> Self

Allow more than one option at a time (singleSelect: false). The default here is single-select, inverting the reference’s own default so the simpler mode is the one a caller gets for free.

pub fn max_selections(self, max: usize) -> Self

Cap a multi-select at max options (maxSelections); 0 is unlimited. Deselecting is never capped.

pub fn open(self, open: bool) -> Self

Hand a kept-mounted panel the app’s open flag, so closing it plays the host’s exit ramp instead of vanishing.

pub fn searchable(self, searchable: bool) -> Self

Show the search field above the option list (searchEnabled).

pub fn query(self, query: impl Into<String>) -> Self

Hand the panel the app-confirmed filter query. Only rendered when searchable is set; the filter itself applies regardless, so an app may drive it from its own field.

pub fn on_query<F: Fn(&mut State, String) + 'static>(self, on_query: F) -> Self

Set the query callback: each edit of the search field reports the text it requests (onSearchChanged).

pub fn loading(self, loading: bool) -> Self

Show the reference’s centered busy row instead of the option list — the panel half of the async poll seam (see the module docs).

pub fn error(self, error: Option<String>) -> Self

Show a load failure instead of the option list (m3e_dropdown_menu_panel.dart:148’s _errorMessage).

pub fn empty_text(self, text: impl Into<String>) -> Self

Replace the empty-state message (noItemsFoundText).

pub fn max_height(self, max_height: f64) -> Self

Cap the panel’s height, past which it scrolls (maxHeight).

pub fn side(self, side: OverlaySide) -> Self

Set the side the panel opens on (bottom by default). The reference’s expandDirection up/down map onto this; its auto is the anchored host’s own collision flip, which is on by default.

pub fn align(self, align: OverlayAlign) -> Self

Set the cross-axis alignment (start by default, the edge the reference’s CompositedTransformFollower pins).

pub fn offset(self, offset: f64) -> Self

Set the gap between field and panel (marginTop, 4dp by default).

pub fn on_open<F: Fn(&mut State, bool) + 'static>(self, on_open: F) -> Self

Set the open callback. Fired with false by a light dismiss, by Escape once the host holds focus, and by a single-select activation — the reference’s _selectSingleItem closes the dropdown after picking.

Trait Implementations

impl<State: 'static> View<State> for DropdownView<State>

type Element = AnchoredOverlayWidget

The retained widget this view produces.

fn build(&self, ctx: &mut BuildCtx<'_>) -> AnchoredOverlayWidget

Materialise a fresh widget for this view.

fn rebuild( &self, prev: &Self, element: &mut AnchoredOverlayWidget, ctx: &mut BuildCtx<'_>, ) -> ChangeFlags

Reconcile prev (the previous view of the same type) against the live element, mutating it in place and reporting what changed.

fn teardown(&self, element: &mut AnchoredOverlayWidget, ctx: &mut BuildCtx<'_>)

Tear down element when this view is being removed.

fn message(&self, _element: &mut Self::Element, _state: &mut State)

Deliver an event message to this view, mutating application state.