Struct Radio

pub struct Radio<Msg: Clone> {
    pub selected: bool,
    pub on_select: Option<Msg>,
    pub label: Option<String>,
    pub id: Option<WidgetId>,
}

One option inside a mutually-exclusive group.

Renders a circle with a centred dot when selected. Unlike Checkbox, a radio is meaningful only as part of a group: the group is the application’s responsibility — define an enum for the choices, store the current value, and build one Radio per variant with selected = current == this_variant.

#[ derive( Clone, PartialEq ) ]
enum Priority { Low, Medium, High }
// In view():
column()
    .push( radio( self.priority == Priority::Low    ).label( "Low"    ).on_select( Msg::SetPriority( Priority::Low    ) ) )
    .push( radio( self.priority == Priority::Medium ).label( "Medium" ).on_select( Msg::SetPriority( Priority::Medium ) ) )
    .push( radio( self.priority == Priority::High   ).label( "High"   ).on_select( Msg::SetPriority( Priority::High   ) ) )
.into()

ltk does not enforce mutual exclusion automatically; the application’s update decides which variant becomes active when a radio is selected.

Fields

selected: bool

Whether this option is currently selected. Drawn from this field every frame.

on_select: Option<Msg>

Message emitted when the user picks this option. None leaves the radio inert.

label: Option<String>

Optional label drawn to the right of the circle.

id: Option<WidgetId>

Optional stable identifier for focus management.

Implementations

impl<Msg: Clone> Radio<Msg>

pub fn new(selected: bool) -> Self

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

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

Set the message emitted when this option is picked. The application’s update is responsible for flipping the group’s current value.

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

Set a text label rendered to the right of the circle.

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

Assign a stable identifier for focus management.

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

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

Focus ring on the outer circle extends FOCUS_W + 2 + FOCUS_W/2 ≈ 6.5 px beyond the circle (which sits flush with the widget’s left edge).

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

Trait Implementations

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

fn from(r: Radio<Msg>) -> Self

Converts to this type from the input type.