vizia_core/views/
switch.rs

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            .role(Role::Switch)
121            .navigable(true)
122    }
123}
124
125impl Handle<'_, Switch> {
126    /// Set the callback triggered when the Switch is pressed.
127    ///
128    /// # Examples
129    ///
130    /// ```
131    /// # use vizia_core::prelude::*;
132    /// #
133    /// # #[derive(Lens)]
134    /// # struct AppData {
135    /// #     value: bool,
136    /// # }
137    /// #
138    /// # impl Model for AppData {}
139    /// #
140    /// # enum AppEvent {
141    /// #     ToggleValue,
142    /// # }
143    /// #
144    /// # let cx = &mut Context::default();
145    /// #
146    /// # AppData { value: false }.build(cx);
147    /// #
148    /// Switch::new(cx, AppData::value)
149    ///     .on_toggle(|cx| cx.emit(AppEvent::ToggleValue));
150    /// ```
151    pub fn on_toggle<F>(self, callback: F) -> Self
152    where
153        F: 'static + Fn(&mut EventContext),
154    {
155        self.modify(|switch| switch.on_toggle = Some(Box::new(callback)))
156    }
157}
158
159impl View for Switch {
160    fn element(&self) -> Option<&'static str> {
161        Some("switch")
162    }
163
164    fn event(&mut self, cx: &mut EventContext, event: &mut Event) {
165        event.map(|window_event, meta| match window_event {
166            WindowEvent::Press { mouse } => {
167                let over = if *mouse { cx.mouse.left.pressed } else { cx.focused() };
168                if over == cx.current() && meta.target == cx.current() && !cx.is_disabled() {
169                    if let Some(callback) = &self.on_toggle {
170                        (callback)(cx);
171                    }
172                }
173            }
174            WindowEvent::ActionRequest(action) => match action.action {
175                Action::Click if !cx.is_disabled() => {
176                    if let Some(callback) = &self.on_toggle {
177                        (callback)(cx);
178                    }
179                }
180                _ => {}
181            },
182            _ => {}
183        });
184    }
185}
vizia_core/views/switch.rs

vizia_core/views/
switch.rs
