Struct Toggle

pub struct Toggle<Msg: Clone> { /* private fields */ }

A two-state on / off switch.

Renders as a horizontal pill with a circular thumb that slides between the off (left, divider colour) and on (right, accent colour) positions. The widget is stateless: the application owns value and rebuilds the toggle from its current state on every frame. Tapping or pressing Enter / Space while focused emits the message configured with Self::on_toggle — the app’s update is then expected to flip the bool and re-render.

// In view():
toggle( self.wifi_enabled )
    .label( "Wi-Fi" )
    .on_toggle( Msg::ToggleWifi )

See also Checkbox for binary opt-in controls (terms acceptance, multi-select form fields) where the pill-style affordance is too prominent.

Implementations

impl<Msg: Clone> Toggle<Msg>

pub fn new(value: bool) -> Self

Create a toggle in the given state, with no label and no callback.

Wire activation through Self::on_toggle before adding it to a widget tree, otherwise the toggle is decorative.

pub fn on_toggle(self, msg: Msg) -> Self

Set the message emitted when the toggle is activated (tap, Enter or Space while focused). The application’s update is responsible for flipping value in response.

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

Set a text label rendered to the left of the track. The toggle’s preferred width grows to fit label_width + gap + track_width, capped at the parent-supplied max_width.

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

Assign a stable identifier so the application can target this toggle through crate::App::take_focus_request.

pub fn height(self, h: impl Into<Length>) -> Self

Override the preferred height (default: the theme row height, theme::HEIGHT design px). Accepts any Length so dense layouts can tie the row height to the viewport. When the resolved value falls below the theme row height, the pill (track and thumb) scales down proportionally so it never clips; it never grows beyond its theme size.

pub fn preferred_size(&self, max_width: f32, canvas: &Canvas) -> (f32, f32)

Return the preferred (width, height) given available max_width.

Width is track_width for an unlabelled toggle, or label_width + gap + track_width (clamped to max_width) when a label is set. Height is the theme-defined row height.

pub fn paint_bounds(&self, rect: Rect) -> Rect

Bounding box of everything painted at rect across all states. The focus ring is drawn as track_rect.expand( FOCUS_W + 2 ) with a stroke of width FOCUS_W, so it extends FOCUS_W + 2 + FOCUS_W/2 ≈ 6.5 px beyond the track. Since the track sits at the right edge of rect, the ring can extend that far outside the widget’s layout rect.

pub fn draw(&self, canvas: &mut Canvas, rect: Rect, focused: bool)

Trait Implementations

impl<Msg: Clone + 'static> From<Toggle<Msg>> for Element<Msg>

fn from(t: Toggle<Msg>) -> Self

Converts to this type from the input type.