Struct RadioButton 

pub struct RadioButton { /* private fields */ }

A single radio button option that writes value into a shared Signal<usize> on selection.

Implementations

impl RadioButton

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

Run f when the user selects this button and it was not already selected, with this button’s value and an EventContext, so it can do what a bare Signal write cannot (ctx.send_intent(...), ctx.set_locale(...), opening a window). Fires for the pointer, for Space, and for an assistive-technology Click.

Re-activating the selected button writes the signal, as every path does, but reports nothing: that is not a change. Programmatic writes to the bound signal report nothing either — there is no event in flight to carry. Observe the signal for those.

pub fn new(value: usize, selected: Signal<usize>) -> Self

Create a radio button with the given value and shared selection signal.

pub fn label(self, label: impl Into<LocalizedString>) -> Self

Set the visible label text displayed to the right of the radio circle.

pub fn caption(self, text: impl Into<LocalizedString>) -> Self

Secondary explanatory text rendered below the label, left-aligned with the label (not the radio circle). Uses the small / text_secondary style. Has no effect unless label(...) is also set.

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

Override the label’s text style (font, size, weight). Accepts a TextStyleRole, a TextStyle, or a Signal of either. Default is TextStyleRole::Body.

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

Override the label’s text color. Accepts Color, a theme role, or a Signal of either. Default is TextRole::Primary. A role still dims to the disabled color when the radio button is disabled; a literal Color stays as given.

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

Override the caption’s text style. Default is TextStyleRole::Small.

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

Override the caption’s text color. Accepts Color, a theme role, or a Signal of either. Default is TextRole::Secondary. A role still dims to the disabled color when the radio button is disabled; a literal Color stays as given.

pub fn enabled(self, enabled: impl Into<Prop<bool>>) -> Self

Set the enabled state, statically or reactively. Forwarded to the arena via ctx.enabled_when(self_id, self.enabled.clone()) at build time.

pub fn variant(self, variant: RadioVariant) -> Self

Pick the design-language variant. Default Circle. The active RadioStyle impl decides what the variant means visually.

pub fn style(self, style: impl RadioStyle) -> Self

Per-call style override. Replaces the theme-wide default RadioStyle for just this RadioButton instance.

pub fn tooltip(self, text: impl Into<LocalizedString>) -> Self

Attach a plain single-line tooltip shown on hover.

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

Attach a rich tooltip resolved from the app-wide tooltip registry. See Button::rich_tooltip.

pub fn rich_tooltip_content(self, content: TooltipContent) -> Self

Attach a rich tooltip driven by inline TooltipContent.

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

Attach a composite tooltip — third tier, hosting an arbitrary widget tree. See Button::composite_tooltip.

Trait Implementations

impl Debug for RadioButton

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

Formats the value using the given formatter.

impl Widget for RadioButton

Internal interaction state — local to this widget’s handlers; the active RadioStyle only sees the four derived boolean signals

fn hit_distance(&self, local_point: Point, bounds: Rect) -> Option<f32>

The first implementer of the hit-targeting shape hook: a labelled radio is its whole row, but a bare one is a disc inside a square box.

A RadioButton with a label is tappable across the label too — the row is the target — so the default rectangular distance is exactly right and this returns it unchanged. A bare radio (a cell in a table, a tight option grid) is a 19 dp disc centred in a 24 dp box, and measuring a near miss to the box would offer the same reach diagonally past its corner as straight out from its edge — where the corner is 3 dp further from the thing the user aimed at. Measuring to the disc makes the slop follow the silhouette, so a miss past the corner loses to a neighbour that is genuinely nearer.

This is consulted only by the miss-only slop pass, never by the exact one, so a click inside the box’s corner still selects the radio exactly as it always has — hit_shape is deliberately left alone.

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

Compose child widgets. Called once after the widget is placed in the arena, and again whenever the widget is marked for rebuild — a BindingLevel::Rebuild binding, rebuild_single_widget, or a density switch. A theme or locale switch does not rebuild: set_theme and set_locale mark layout + paint dirty and leave the built subtree standing, so anything derived from the theme or the locale must be read per pass or bound to a signal rather than captured here. 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 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 culls_children(&self) -> bool

Whether this widget decides, on every layout pass, which of its children exist at all.

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 accessible_title_node(&self) -> Option<WidgetId>

The widget that paints this one’s title, when it has one.

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_proxy(&self) -> Option<WidgetId>

The descendant whose accessibility node stands for this widget.

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

Which descendant a keyboard request for a context menu should target.

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 clips_children(&self) -> bool

Whether this widget clips its children to its bounds.

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 accepts_child_hit(&self, _child: WidgetId, _point: Point) -> bool

Veto a hit on one of this widget’s direct children, per point.

fn hit_outset(&self, _kind: PointerKind, _tokens: &InputTokens) -> EdgeInsets

How far outside its own bounds this widget still absorbs a press, per edge, for the pointer that is asking.

fn hit_slop(&self, _kind: PointerKind, _tokens: &InputTokens) -> Option<HitSlop>

This widget’s own say in the miss-only slop pass, overriding the density default for its node.

fn target_regions(&self, _bounds: Rect) -> Vec<TargetRegion>

The interactive sub-regions this widget paints inside its own single node — a scroll bar’s thumb, a slider’s knob, a header cell’s filter affordance.

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).