Struct Accordion 

pub struct Accordion { /* private fields */ }

A collapsible section widget whose header button shows or hides attached content.

Supply the title and a Signal<bool> for the expanded state, then attach content via .content(w) or .content_id(id). The signal can be toggled externally (e.g. from a “collapse all” button) and the disclosure animation will follow.

Implementations

impl Accordion

pub fn new(title: impl Into<LocalizedString>, expanded: Signal<bool>) -> Self

Create a new accordion with the given title and an external expanded signal.

The accordion starts collapsed or expanded according to the initial value of expanded. Toggling the signal later drives the disclosure animation.

pub fn orientation(self, orientation: AccordionOrientation) -> Self

Set the header orientation (default AccordionOrientation::Vertical).

pub fn horizontal(self) -> Self

Shorthand for Accordion::orientation(AccordionOrientation::Horizontal).

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

Make the expanded content fill the accordion’s allotted space (the leftover after the header) — instead of the default natural-height disclosure — while keeping the collapse/expand animated. Use when the accordion lives in a fixed-size slot such as a Splitter pane (a dock panel): the content lays out at exactly the available size (no narrow content, no overflow) and the header tween still plays. Default false.

pub fn on_header_drag(self, f: impl Fn(&mut EventContext<'_>) + 'static) -> Self

Make the header a drag source: a drag gesture starting on it fires f (which should begin a drag, e.g. ctx.start_drag(source, payload)). Tap-to-toggle is unaffected — the gesture arena tells a tap from a drag.

pub fn trailing(self, widget: impl Widget + 'static) -> Self

Place a widget at the trailing end of the header, before the disclosure chevron — an options (⋮) button, an inline action toolbar, etc. The slot’s own controls capture their gestures (innermost hit wins), so clicking them does not toggle the accordion. Mirrors ToolBoxItem::trailing / TabWidget::bar_trailing_slot.

pub fn trailing_id(self, id: WidgetId) -> Self

Like trailing but takes a pre-registered widget id — for callers that must build the slot in-context (e.g. a slot that itself adds boxed children). Takes precedence over trailing.

pub fn title_color(self, color: impl Into<ColorProp>) -> Self

Override the header foreground color used for the title text and chevron icon. Defaults to [TextRole::Primary]. Accepts a literal Color, a TextRole/SurfaceRole, or a Signal<Color>.

pub fn title_style(self, style: impl Into<TextStyleProp>) -> Self

Override the header title’s text style. Use this to make the disclosure label smaller (e.g. inside a tooltip) or to match a non-body typography role. Accepts a static TextStyle or a [TextStyleRole].

pub fn content_id(self, id: WidgetId) -> Self

Set the content widget by pre-registered ID.

pub fn content(self, widget: impl Widget + 'static) -> Self

Set an inline content widget (deferred insertion).

Trait Implementations

impl Debug for Accordion

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Widget for Accordion

fn build(&mut self, ctx: &mut BuildContext<'_>) -> Vec<WidgetId>

Compose child widgets. Called once after the widget is placed in the arena, and again on environment change (theme switch, locale switch). Takes &mut self — store child IDs, signal handles, any state needed later. Returns the list of root child IDs (empty for leaf widgets).

fn layout_response( &self, proposal: SizeProposal, ctx: &LayoutContext<'_>, ) -> LayoutResponse

Respond to the parent’s size proposal with this widget’s wanted size, grow/shrink weights, and compression floor (see [LayoutResponse]).

fn place_children( &self, bounds: Rect, _proposal: SizeProposal, children: &mut [WidgetPlacement], ctx: &LayoutContext<'_>, )

Position children within the allocated bounds.

fn accessibility(&self, builder: &mut AccessNodeBuilder)

Declare this widget’s accessibility identity.

fn children(&self) -> Vec<WidgetId>

Return the child widget IDs that this widget manages.

fn clips_children(&self) -> bool

Whether this widget clips its children to its bounds.

fn type_name(&self) -> &'static str

Concrete type name of this widget (e.g. "teksilo_widgets::button::Button"). The default implementation resolves at the impl site via std::any::type_name::<Self>(), so calls through &dyn Widget correctly dispatch to the monomorphized fn for the concrete type — getting the concrete name through the vtable without per-impl boilerplate.

fn cacheable_layout(&self) -> bool

Whether this widget’s layout_response may be memoized by the per-pass layout cache. Defaults to true.

fn paint(&self, _bounds: Rect, _canvas: &mut Canvas, _ctx: &PaintContext<'_>)

Draw the widget’s visual representation.

fn wants_after_paint(&self) -> bool

Whether this widget wants its after_paint hook to fire each frame. Returning false (the default) saves a virtual call per widget per frame for the vast majority of widgets that don’t aggregate descendant geometry.

fn after_paint(&self, _view: &WidgetTreeView<'_>, _ctx: &PaintContext<'_>)

Called once per frame after this widget’s subtree has finished painting. Receives a read-only view of the layout-resolved arena so a parent can read its descendants’ final bounds — e.g. TitleBar aggregates its drag region and control-button rects into a single HitRegions payload for the Windows backend’s WM_NCHITTEST.

fn wants_post_paint(&self) -> bool

Whether this widget wants its post_paint hook to fire each frame. Returning false (the default) saves a virtual call per widget per frame for the vast majority of widgets that don’t draw a foreground over their children.

fn post_paint( &self, _bounds: Rect, _canvas: &mut Canvas, _ctx: &PaintContext<'_>, )

Draw a foreground layer over this widget’s children.

fn wants_descendant_redirects(&self) -> bool

Whether this widget wants the AT walker to consult its a11y_redirect_descendant hook for every descendant during AT tree emission, not just its direct arena children.

fn a11y_redirect_descendant( &self, _self_id: WidgetId, _descendant: WidgetId, ) -> Option<NodeId>

Optional redirection hook for AT-tree placement of a child.

fn accessible_title_hint(&self) -> Option<String>

Suggest an accessible title to an enclosing container that wraps this widget as content — typically a modal / dialog shell that wants to propagate the inner content’s visible title as the shell’s own accessible name.

fn initial_focus_hint(&self) -> Option<WidgetId>

Optional hint that directs initial focus to a specific descendant when this widget is the root of a deferred-built modal surface.

fn accessibility_children(&self) -> Option<Vec<WidgetId>>

Optional override for the child ORDER presented to assistive technology, when it must differ from the paint / z-order child order returned by children.

fn as_any(&self) -> Option<&(dyn Any + 'static)>

Downcast hook. Default implementation returns None; concrete widgets override with Some(self) when they want to expose their concrete type to test-level introspection or reflection. The trait already bounds on std::any::Any so concrete types satisfy the 'static requirement.

fn as_any_mut(&mut self) -> Option<&mut (dyn Any + 'static)>

Mutable counterpart of as_any. Default returns None; widgets that want to expose mutable state to tests (e.g. so a test can mutate a Scene inside a SceneView post-layout) override with Some(self). Should follow the same opt-in pattern as as_any: only widgets that opt into & introspection should opt into &mut.

fn focus_reveal_rect(&self, _bounds: Rect) -> Option<Rect>

The rectangle (in absolute tree coordinates) that best represents this widget when the framework reveals it into an ancestor scroll area on focus gain. Returning None (the default) reveals the widget’s whole bounds — correct for most controls.

fn hit_shape(&self, _local_point: Point, _bounds: Rect) -> bool

Whether the point lies inside this widget’s actual shape, not just its rectangular bounds. Consulted by hit-testing right after the bounds check: returning false for a point that is inside the bounding box makes the widget transparent to the click there, so it falls through to whatever sibling is painted underneath (the same machinery as a fully pass-through node, but shape-aware).

fn preserves_children_on_rebuild(&self) -> bool

How rebuild_single_widget treats this widget’s existing children when re-running its build().

fn tooltip_has_content(&self) -> bool

Whether this widget, used as tooltip content, currently has anything worth showing.

fn declare_shortcuts(&self) -> Vec<Shortcut>

Declare the rebindable keyboard shortcuts this widget exposes, without installing handlers. The framework calls this at arena insertion time (before build()) and at certain lazy boundaries (e.g. Switcher walks declarations on its not-yet-mounted Pending slots), so settings UIs and the ShortcutRegistry see the keystrokes the moment the owning container mounts — even if build() hasn’t run.

fn take_handler_set(&mut self) -> Option<HandlerSet>

Extract attached handler set from a WidgetWithHandlers wrapper. Called during arena insertion to transfer handlers to the WidgetNode. Default: returns None (no attached handlers).