Struct Checkbox 

pub struct Checkbox<S, M> { /* private fields */ }

A boolean control: marker left, label right, the whole row one hit target.

A click anywhere on the row toggles, as do Enter and Space while focused. Hover and focus raise the row the way a small ghost button raises, so pointer and keyboard users both always see what they are on.

The checked state lives in app state and arrives through checked; without that binding the checkbox paints but is not focusable and answers no events. With the markers chosen freely, the same component serves as a switch ([ON]/[off]) or an ASCII toggle ([x]/[ ]) — see the checkbox demo.

Its markers answer to checked/unchecked where the selection controls say selected/unselected: a checkbox holds one row whose two states are its content, not a choice among many.

Implementations

impl<S, M> Checkbox<S, M>

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

Construct a checkbox labelled label.

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

The marker shown while checked.

Any string works, including multi-character pairs like [x]; the marker column takes the wider of the pair, so the label holds still as the state flips. Pair it with unchecked_marker so both states read as one control — [ON]/[off] is a switch, [x]/[ ] an ASCII checkbox.

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

The marker shown while unchecked.

pub fn checked( self, read: impl Fn(&S) -> bool + 'static, on_change: impl Fn(bool) -> M + 'static, ) -> Self

Bind the checked state and the message that flips it.

read runs against current app state during rendering and event handling. on_change receives the requested state — true after a toggle onto checked, false after one onto unchecked. Without this binding the checkbox is not focusable and answers no events.

pub const fn disabled(self, disabled: bool) -> Self

Paint and answer muted, ignoring every event.

pub fn style(self, style: impl Fn(&Theme) -> CheckboxStyle + 'static) -> Self

Supply exact colors, taking precedence over the theme.

pub fn width(&self) -> u16

Columns this checkbox paints: the marker column (the wider of the two markers), one space, the label — the same in both states, so a row sized from this holds its label still. See CheckboxWidget::width.

Trait Implementations

impl<S: 'static, M: 'static> Component<S, M> for Checkbox<S, M>

fn prepare(&mut self, state: &S)

Prepare this component from the state it is being declared with.

fn declare(&mut self, _ctx: &mut DeclareCtx<'_, S, M>)

Declare the component: lay out its area, declare its descendants, and record whatever handle_event will need to read back.

fn paint(&mut self, ctx: &mut PaintCtx<'_, S>)

Paint the component. ctx carries the paint surface, area, app state, theme, and interaction state.

fn handle_event( &mut self, event: &Event, _state: &S, _ctx: &mut EventCtx<'_>, ) -> EventResult<M>

Offer this component an event.

fn scope_options(&self) -> ScopeOptions

The scope this component opens around its descendants. Read once, before declare, so it cannot depend on paint.

fn interaction_area(&self, area: Rect) -> Rect

Return the area used for focus, hit-testing, and event routing.

fn reveal_in_viewport( &mut self, _target: Rect, _state: &State, _ctx: &mut EventCtx<'_>, )

Bring target into view inside this component’s viewport.

impl<S, M> Debug for Checkbox<S, M>

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

Formats the value using the given formatter.

impl<S: 'static, M: 'static> MeasuredComponent<S, M> for Checkbox<S, M>

fn measure(&self) -> Size

The component’s preferred width and height in terminal cells.