1/// A trait for elements that can be toggled.
 2///
 3/// Implement this for elements that are visually distinct
 4/// when in two opposing states, like checkboxes or switches.
 5pub trait Toggleable {
 6    /// Sets whether the element is selected.
 7    fn toggle_state(self, selected: bool) -> Self;
 8}
 9
10/// Represents the selection status of an element.
11#[derive(Debug, Default, PartialEq, Eq, Hash, Clone, Copy)]
12pub enum ToggleState {
13    /// The element is not selected.
14    #[default]
15    Unselected,
16    /// The selection state of the element is indeterminate.
17    Indeterminate,
18    /// The element is selected.
19    Selected,
20}
21
22impl ToggleState {
23    /// Returns the inverse of the current selection status.
24    ///
25    /// Indeterminate states become selected if inverted.
26    pub fn inverse(&self) -> Self {
27        match self {
28            Self::Unselected | Self::Indeterminate => Self::Selected,
29            Self::Selected => Self::Unselected,
30        }
31    }
32}
33
34impl From<bool> for ToggleState {
35    fn from(selected: bool) -> Self {
36        if selected {
37            Self::Selected
38        } else {
39            Self::Unselected
40        }
41    }
42}
43
44impl From<Option<bool>> for ToggleState {
45    fn from(selected: Option<bool>) -> Self {
46        match selected {
47            Some(true) => Self::Selected,
48            Some(false) => Self::Unselected,
49            None => Self::Unselected,
50        }
51    }
52}