vizia_core/views/
switch.rs

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1use crate::prelude::*;
2
3/// A Switch used to display and toggle a boolean state.
4///
5/// Clicking on the Switch with the left mouse button triggers the `on_toggle` callback.
6///
7/// # Examples
8///
9/// ## Basic Switch
10///
11/// The Switch must bound to some boolean data.
12///
13/// ```
14/// # use vizia_core::prelude::*;
15/// #
16/// # #[derive(Lens)]
17/// # struct AppData {
18/// #     value: bool,
19/// # }
20/// #
21/// # impl Model for AppData {}
22/// #
23/// # let cx = &mut Context::default();
24/// #
25/// # AppData { value: false }.build(cx);
26/// #
27/// Switch::new(cx, AppData::value);
28/// ```
29///
30/// ## Switch with an action
31///
32/// A Switch can be used to trigger a callback when toggled. Usually this is emitting an
33/// event responsible for changing the data the Switch is bound to.
34///
35/// ```
36/// # use vizia_core::prelude::*;
37/// #
38/// # #[derive(Lens)]
39/// # struct AppData {
40/// #     value: bool,
41/// # }
42/// #
43/// # impl Model for AppData {}
44/// #
45/// # enum AppEvent {
46/// #     ToggleValue,
47/// # }
48/// #
49/// # let cx = &mut Context::default();
50/// #
51/// # AppData { value: false }.build(cx);
52/// #
53/// Switch::new(cx, AppData::value).on_toggle(|cx| cx.emit(AppEvent::ToggleValue));
54/// ```
55///
56/// ## Switch with a label
57///
58/// A Switch is usually used with a label next to it describing what data the Switch
59/// is bound to or what the Switch does when pressed. This can be done, for example, by
60/// wrapping the Switch in an [`HStack`](crate::prelude::HStack) and adding a [`Label`](crate::prelude::Label)
61/// to it.
62///
63/// ```
64/// # use vizia_core::prelude::*;
65/// #
66/// # #[derive(Lens)]
67/// # struct AppData {
68/// #     value: bool,
69/// # }
70/// #
71/// # impl Model for AppData {}
72/// #
73/// # let cx = &mut Context::default();
74/// #
75/// # AppData { value: false }.build(cx);
76/// #
77/// HStack::new(cx, |cx| {
78///     Switch::new(cx, AppData::value);
79///     Label::new(cx, "Press me");
80/// });
81/// ```
82pub struct Switch {
83    on_toggle: Option<Box<dyn Fn(&mut EventContext)>>,
84}
85
86impl Switch {
87    /// Creates a new Switch.
88    ///
89    /// # Examples
90    ///
91    /// ```
92    /// # use vizia_core::prelude::*;
93    /// #
94    /// # #[derive(Lens)]
95    /// # struct AppData {
96    /// #     value: bool,
97    /// # }
98    /// #
99    /// # impl Model for AppData {}
100    /// #
101    /// # let cx = &mut Context::default();
102    /// #
103    /// # AppData { value: false }.build(cx);
104    /// #
105    /// Switch::new(cx, AppData::value);
106    /// ```
107    pub fn new(cx: &mut Context, checked: impl Lens<Target = bool>) -> Handle<Self> {
108        Self { on_toggle: None }
109            .build(cx, |cx| {
110                Element::new(cx)
111                    .class("switch-handle-bg")
112                    .hoverable(false)
113                    .position_type(PositionType::Absolute);
114                Element::new(cx)
115                    .class("switch-handle")
116                    .hoverable(false)
117                    .position_type(PositionType::Absolute);
118            })
119            .checked(checked)
120            .navigable(true)
121    }
122}
123
124impl Handle<'_, Switch> {
125    /// Set the callback triggered when the Switch is pressed.
126    ///
127    /// # Examples
128    ///
129    /// ```
130    /// # use vizia_core::prelude::*;
131    /// #
132    /// # #[derive(Lens)]
133    /// # struct AppData {
134    /// #     value: bool,
135    /// # }
136    /// #
137    /// # impl Model for AppData {}
138    /// #
139    /// # enum AppEvent {
140    /// #     ToggleValue,
141    /// # }
142    /// #
143    /// # let cx = &mut Context::default();
144    /// #
145    /// # AppData { value: false }.build(cx);
146    /// #
147    /// Switch::new(cx, AppData::value)
148    ///     .on_toggle(|cx| cx.emit(AppEvent::ToggleValue));
149    /// ```
150    pub fn on_toggle<F>(self, callback: F) -> Self
151    where
152        F: 'static + Fn(&mut EventContext),
153    {
154        self.modify(|switch| switch.on_toggle = Some(Box::new(callback)))
155    }
156}
157
158impl View for Switch {
159    fn element(&self) -> Option<&'static str> {
160        Some("switch")
161    }
162
163    fn event(&mut self, cx: &mut EventContext, event: &mut Event) {
164        event.map(|window_event, meta| match window_event {
165            WindowEvent::Press { mouse } => {
166                let over = if *mouse { cx.mouse.left.pressed } else { cx.focused() };
167                if over == cx.current() && meta.target == cx.current() && !cx.is_disabled() {
168                    if let Some(callback) = &self.on_toggle {
169                        (callback)(cx);
170                    }
171                }
172            }
173
174            _ => {}
175        });
176    }
177}
vizia_core/views/switch.rs

vizia_core/views/
switch.rs
