cranpose_ui/modifier/
toggleable.rs

1use std::rc::Rc;
2
3use cranpose_foundation::{SemanticsWidgetRole, ToggleableState};
4
5use super::{Modifier, SemanticsConfiguration, inspector_metadata};
6
7impl Modifier {
8    /// Make the component a two-state control.
9    ///
10    /// This is Compose's `Modifier.toggleable(value, enabled, role,
11    /// onValueChange)`: a click hands the callback the **new** value, so a
12    /// caller writes `.toggleable(checked, None, None, move |next|
13    /// state.set(next))` and never has to read the old one back out of its own
14    /// state to invert it.
15    ///
16    /// `role` is what a screen reader announces the control **as** — "switch",
17    /// "checkbox" — before it is acted on, and it is genuinely optional: a
18    /// toggleable row could be either, so Compose's parameter defaults to
19    /// `null` and so does passing `None` here. Wear's own `SwitchButton` leaves
20    /// it unset on the row and puts `Role.Switch` on the `Switch` control
21    /// inside, which merges up into the same node; naming it on the row reaches
22    /// the same announcement without leaning on a merge rule.
23    ///
24    /// A toggleable control with no role is not silent — the description and
25    /// the state below still speak — but it is announced as an unnamed
26    /// something the reader cannot say is toggleable, which is the whole of the
27    /// difference.
28    ///
29    /// The **state** it publishes regardless: `toggled`, Compose's
30    /// `toggleableState`, so a reader landing on the row says whether it is on
31    /// without the caller spelling it into the description. `description` stays
32    /// because a row still needs a name, and a caller that wants the state
33    /// spoken a particular way ("Haptics, on") can still say it there.
34    pub fn toggleable(
35        self,
36        value: bool,
37        description: Option<String>,
38        role: Option<SemanticsWidgetRole>,
39        on_value_change: impl Fn(bool) + 'static,
40    ) -> Self {
41        self.tri_state_toggleable(value.into(), description, role, move || {
42            on_value_change(!value);
43        })
44    }
45
46    /// Makes the component a control that is on, off or partly on, such as
47    /// a check box over a list whose items are partly checked. A click calls
48    /// `on_click`, which decides the next state.
49    ///
50    /// This is Compose's `Modifier.triStateToggleable(state, enabled, role,
51    /// onClick)`. Readers hear the state: a partly checked box reads as
52    /// "mixed" or "partially checked".
53    pub fn tri_state_toggleable(
54        self,
55        state: ToggleableState,
56        description: Option<String>,
57        role: Option<SemanticsWidgetRole>,
58        on_click: impl Fn() + 'static,
59    ) -> Self {
60        let on_click = Rc::new(on_click);
61        let modifier = Modifier::empty()
62            .clickable(move |_point| on_click())
63            .with_inspector_metadata(inspector_metadata("toggleable", move |info| {
64                info.add_property("state", format!("{state:?}"));
65                info.add_property("onClick", "provided");
66            }))
67            .then(Modifier::empty().stable_semantics(
68                move |config: &mut SemanticsConfiguration| {
69                    config.is_clickable = true;
70                    config.toggled = Some(state);
71                    if let Some(description) = &description {
72                        config.content_description = Some(description.clone());
73                    }
74                    if let Some(role) = role {
75                        config.role = Some(role);
76                    }
77                },
78            ));
79        self.then(modifier)
80    }
81}
82
83#[cfg(test)]
84#[path = "tests/toggleable_tests.rs"]
85mod tests;
cranpose_ui/modifier/toggleable.rs

cranpose_ui/modifier/
toggleable.rs
