iced_widget/
radio.rs

1//! Radio buttons let users choose a single option from a bunch of options.
2//!
3//! # Example
4//! ```no_run
5//! # mod iced { pub mod widget { pub use iced_widget::*; } pub use iced_widget::Renderer; pub use iced_widget::core::*; }
6//! # pub type Element<'a, Message> = iced_widget::core::Element<'a, Message, iced_widget::Theme, iced_widget::Renderer>;
7//! #
8//! use iced::widget::{column, radio};
9//!
10//! struct State {
11//!    selection: Option<Choice>,
12//! }
13//!
14//! #[derive(Debug, Clone, Copy)]
15//! enum Message {
16//!     RadioSelected(Choice),
17//! }
18//!
19//! #[derive(Debug, Clone, Copy, PartialEq, Eq)]
20//! enum Choice {
21//!     A,
22//!     B,
23//!     C,
24//!     All,
25//! }
26//!
27//! fn view(state: &State) -> Element<'_, Message> {
28//!     let a = radio(
29//!         "A",
30//!         Choice::A,
31//!         state.selection,
32//!         Message::RadioSelected,
33//!     );
34//!
35//!     let b = radio(
36//!         "B",
37//!         Choice::B,
38//!         state.selection,
39//!         Message::RadioSelected,
40//!     );
41//!
42//!     let c = radio(
43//!         "C",
44//!         Choice::C,
45//!         state.selection,
46//!         Message::RadioSelected,
47//!     );
48//!
49//!     let all = radio(
50//!         "All of the above",
51//!         Choice::All,
52//!         state.selection,
53//!         Message::RadioSelected
54//!     );
55//!
56//!     column![a, b, c, all].into()
57//! }
58//! ```
59use crate::core::alignment;
60use crate::core::border::{self, Border};
61use crate::core::layout;
62use crate::core::mouse;
63use crate::core::renderer;
64use crate::core::text;
65use crate::core::touch;
66use crate::core::widget;
67use crate::core::widget::tree::{self, Tree};
68use crate::core::window;
69use crate::core::{
70    Background, Color, Element, Event, Layout, Length, Pixels, Rectangle, Shell, Size, Theme,
71    Widget,
72};
73
74/// A circular button representing a choice.
75///
76/// # Example
77/// ```no_run
78/// # mod iced { pub mod widget { pub use iced_widget::*; } pub use iced_widget::Renderer; pub use iced_widget::core::*; }
79/// # pub type Element<'a, Message> = iced_widget::core::Element<'a, Message, iced_widget::Theme, iced_widget::Renderer>;
80/// #
81/// use iced::widget::{column, radio};
82///
83/// struct State {
84///    selection: Option<Choice>,
85/// }
86///
87/// #[derive(Debug, Clone, Copy)]
88/// enum Message {
89///     RadioSelected(Choice),
90/// }
91///
92/// #[derive(Debug, Clone, Copy, PartialEq, Eq)]
93/// enum Choice {
94///     A,
95///     B,
96///     C,
97///     All,
98/// }
99///
100/// fn view(state: &State) -> Element<'_, Message> {
101///     let a = radio(
102///         "A",
103///         Choice::A,
104///         state.selection,
105///         Message::RadioSelected,
106///     );
107///
108///     let b = radio(
109///         "B",
110///         Choice::B,
111///         state.selection,
112///         Message::RadioSelected,
113///     );
114///
115///     let c = radio(
116///         "C",
117///         Choice::C,
118///         state.selection,
119///         Message::RadioSelected,
120///     );
121///
122///     let all = radio(
123///         "All of the above",
124///         Choice::All,
125///         state.selection,
126///         Message::RadioSelected
127///     );
128///
129///     column![a, b, c, all].into()
130/// }
131/// ```
132pub struct Radio<'a, Message, Theme = crate::Theme, Renderer = crate::Renderer>
133where
134    Theme: Catalog,
135    Renderer: text::Renderer,
136{
137    is_selected: bool,
138    on_click: Message,
139    label: String,
140    width: Length,
141    size: f32,
142    spacing: f32,
143    text_size: Option<Pixels>,
144    text_line_height: text::LineHeight,
145    text_shaping: text::Shaping,
146    text_wrapping: text::Wrapping,
147    font: Option<Renderer::Font>,
148    class: Theme::Class<'a>,
149    last_status: Option<Status>,
150}
151
152impl<'a, Message, Theme, Renderer> Radio<'a, Message, Theme, Renderer>
153where
154    Message: Clone,
155    Theme: Catalog,
156    Renderer: text::Renderer,
157{
158    /// The default size of a [`Radio`] button.
159    pub const DEFAULT_SIZE: f32 = 16.0;
160
161    /// The default spacing of a [`Radio`] button.
162    pub const DEFAULT_SPACING: f32 = 8.0;
163
164    /// Creates a new [`Radio`] button.
165    ///
166    /// It expects:
167    ///   * the value related to the [`Radio`] button
168    ///   * the label of the [`Radio`] button
169    ///   * the current selected value
170    ///   * a function that will be called when the [`Radio`] is selected. It
171    ///     receives the value of the radio and must produce a `Message`.
172    pub fn new<F, V>(label: impl Into<String>, value: V, selected: Option<V>, f: F) -> Self
173    where
174        V: Eq + Copy,
175        F: FnOnce(V) -> Message,
176    {
177        Radio {
178            is_selected: Some(value) == selected,
179            on_click: f(value),
180            label: label.into(),
181            width: Length::Shrink,
182            size: Self::DEFAULT_SIZE,
183            spacing: Self::DEFAULT_SPACING,
184            text_size: None,
185            text_line_height: text::LineHeight::default(),
186            text_shaping: text::Shaping::default(),
187            text_wrapping: text::Wrapping::default(),
188            font: None,
189            class: Theme::default(),
190            last_status: None,
191        }
192    }
193
194    /// Sets the size of the [`Radio`] button.
195    pub fn size(mut self, size: impl Into<Pixels>) -> Self {
196        self.size = size.into().0;
197        self
198    }
199
200    /// Sets the width of the [`Radio`] button.
201    pub fn width(mut self, width: impl Into<Length>) -> Self {
202        self.width = width.into();
203        self
204    }
205
206    /// Sets the spacing between the [`Radio`] button and the text.
207    pub fn spacing(mut self, spacing: impl Into<Pixels>) -> Self {
208        self.spacing = spacing.into().0;
209        self
210    }
211
212    /// Sets the text size of the [`Radio`] button.
213    pub fn text_size(mut self, text_size: impl Into<Pixels>) -> Self {
214        self.text_size = Some(text_size.into());
215        self
216    }
217
218    /// Sets the text [`text::LineHeight`] of the [`Radio`] button.
219    pub fn text_line_height(mut self, line_height: impl Into<text::LineHeight>) -> Self {
220        self.text_line_height = line_height.into();
221        self
222    }
223
224    /// Sets the [`text::Shaping`] strategy of the [`Radio`] button.
225    pub fn text_shaping(mut self, shaping: text::Shaping) -> Self {
226        self.text_shaping = shaping;
227        self
228    }
229
230    /// Sets the [`text::Wrapping`] strategy of the [`Radio`] button.
231    pub fn text_wrapping(mut self, wrapping: text::Wrapping) -> Self {
232        self.text_wrapping = wrapping;
233        self
234    }
235
236    /// Sets the text font of the [`Radio`] button.
237    pub fn font(mut self, font: impl Into<Renderer::Font>) -> Self {
238        self.font = Some(font.into());
239        self
240    }
241
242    /// Sets the style of the [`Radio`] button.
243    #[must_use]
244    pub fn style(mut self, style: impl Fn(&Theme, Status) -> Style + 'a) -> Self
245    where
246        Theme::Class<'a>: From<StyleFn<'a, Theme>>,
247    {
248        self.class = (Box::new(style) as StyleFn<'a, Theme>).into();
249        self
250    }
251
252    /// Sets the style class of the [`Radio`] button.
253    #[cfg(feature = "advanced")]
254    #[must_use]
255    pub fn class(mut self, class: impl Into<Theme::Class<'a>>) -> Self {
256        self.class = class.into();
257        self
258    }
259}
260
261impl<Message, Theme, Renderer> Widget<Message, Theme, Renderer>
262    for Radio<'_, Message, Theme, Renderer>
263where
264    Message: Clone,
265    Theme: Catalog,
266    Renderer: text::Renderer,
267{
268    fn tag(&self) -> tree::Tag {
269        tree::Tag::of::<widget::text::State<Renderer::Paragraph>>()
270    }
271
272    fn state(&self) -> tree::State {
273        tree::State::new(widget::text::State::<Renderer::Paragraph>::default())
274    }
275
276    fn size(&self) -> Size<Length> {
277        Size {
278            width: self.width,
279            height: Length::Shrink,
280        }
281    }
282
283    fn layout(
284        &mut self,
285        tree: &mut Tree,
286        renderer: &Renderer,
287        limits: &layout::Limits,
288    ) -> layout::Node {
289        layout::next_to_each_other(
290            &limits.width(self.width),
291            self.spacing,
292            |_| layout::Node::new(Size::new(self.size, self.size)),
293            |limits| {
294                let state = tree
295                    .state
296                    .downcast_mut::<widget::text::State<Renderer::Paragraph>>();
297
298                widget::text::layout(
299                    state,
300                    renderer,
301                    limits,
302                    &self.label,
303                    widget::text::Format {
304                        width: self.width,
305                        height: Length::Shrink,
306                        line_height: self.text_line_height,
307                        size: self.text_size,
308                        font: self.font,
309                        align_x: text::Alignment::Default,
310                        align_y: alignment::Vertical::Top,
311                        shaping: self.text_shaping,
312                        wrapping: self.text_wrapping,
313                    },
314                )
315            },
316        )
317    }
318
319    fn update(
320        &mut self,
321        _tree: &mut Tree,
322        event: &Event,
323        layout: Layout<'_>,
324        cursor: mouse::Cursor,
325        _renderer: &Renderer,
326        shell: &mut Shell<'_, Message>,
327        _viewport: &Rectangle,
328    ) {
329        match event {
330            Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
331            | Event::Touch(touch::Event::FingerPressed { .. }) => {
332                if cursor.is_over(layout.bounds()) {
333                    shell.publish(self.on_click.clone());
334                    shell.capture_event();
335                }
336            }
337            _ => {}
338        }
339
340        let current_status = {
341            let is_mouse_over = cursor.is_over(layout.bounds());
342            let is_selected = self.is_selected;
343
344            if is_mouse_over {
345                Status::Hovered { is_selected }
346            } else {
347                Status::Active { is_selected }
348            }
349        };
350
351        if let Event::Window(window::Event::RedrawRequested(_now)) = event {
352            self.last_status = Some(current_status);
353        } else if self
354            .last_status
355            .is_some_and(|last_status| last_status != current_status)
356        {
357            shell.request_redraw();
358        }
359    }
360
361    fn mouse_interaction(
362        &self,
363        _tree: &Tree,
364        layout: Layout<'_>,
365        cursor: mouse::Cursor,
366        _viewport: &Rectangle,
367        _renderer: &Renderer,
368    ) -> mouse::Interaction {
369        if cursor.is_over(layout.bounds()) {
370            mouse::Interaction::Pointer
371        } else {
372            mouse::Interaction::default()
373        }
374    }
375
376    fn draw(
377        &self,
378        tree: &Tree,
379        renderer: &mut Renderer,
380        theme: &Theme,
381        defaults: &renderer::Style,
382        layout: Layout<'_>,
383        _cursor: mouse::Cursor,
384        viewport: &Rectangle,
385    ) {
386        let mut children = layout.children();
387
388        let style = theme.style(
389            &self.class,
390            self.last_status.unwrap_or(Status::Active {
391                is_selected: self.is_selected,
392            }),
393        );
394
395        {
396            let layout = children.next().unwrap();
397            let bounds = layout.bounds();
398
399            let size = bounds.width;
400            let dot_size = size / 2.0;
401
402            renderer.fill_quad(
403                renderer::Quad {
404                    bounds,
405                    border: Border {
406                        radius: (size / 2.0).into(),
407                        width: style.border_width,
408                        color: style.border_color,
409                    },
410                    ..renderer::Quad::default()
411                },
412                style.background,
413            );
414
415            if self.is_selected {
416                renderer.fill_quad(
417                    renderer::Quad {
418                        bounds: Rectangle {
419                            x: bounds.x + dot_size / 2.0,
420                            y: bounds.y + dot_size / 2.0,
421                            width: bounds.width - dot_size,
422                            height: bounds.height - dot_size,
423                        },
424                        border: border::rounded(dot_size / 2.0),
425                        ..renderer::Quad::default()
426                    },
427                    style.dot_color,
428                );
429            }
430        }
431
432        {
433            let label_layout = children.next().unwrap();
434            let state: &widget::text::State<Renderer::Paragraph> = tree.state.downcast_ref();
435
436            crate::text::draw(
437                renderer,
438                defaults,
439                label_layout.bounds(),
440                state.raw(),
441                crate::text::Style {
442                    color: style.text_color,
443                },
444                viewport,
445            );
446        }
447    }
448}
449
450impl<'a, Message, Theme, Renderer> From<Radio<'a, Message, Theme, Renderer>>
451    for Element<'a, Message, Theme, Renderer>
452where
453    Message: 'a + Clone,
454    Theme: 'a + Catalog,
455    Renderer: 'a + text::Renderer,
456{
457    fn from(radio: Radio<'a, Message, Theme, Renderer>) -> Element<'a, Message, Theme, Renderer> {
458        Element::new(radio)
459    }
460}
461
462/// The possible status of a [`Radio`] button.
463#[derive(Debug, Clone, Copy, PartialEq, Eq)]
464pub enum Status {
465    /// The [`Radio`] button can be interacted with.
466    Active {
467        /// Indicates whether the [`Radio`] button is currently selected.
468        is_selected: bool,
469    },
470    /// The [`Radio`] button is being hovered.
471    Hovered {
472        /// Indicates whether the [`Radio`] button is currently selected.
473        is_selected: bool,
474    },
475}
476
477/// The appearance of a radio button.
478#[derive(Debug, Clone, Copy, PartialEq)]
479pub struct Style {
480    /// The [`Background`] of the radio button.
481    pub background: Background,
482    /// The [`Color`] of the dot of the radio button.
483    pub dot_color: Color,
484    /// The border width of the radio button.
485    pub border_width: f32,
486    /// The border [`Color`] of the radio button.
487    pub border_color: Color,
488    /// The text [`Color`] of the radio button.
489    pub text_color: Option<Color>,
490}
491
492/// The theme catalog of a [`Radio`].
493pub trait Catalog {
494    /// The item class of the [`Catalog`].
495    type Class<'a>;
496
497    /// The default class produced by the [`Catalog`].
498    fn default<'a>() -> Self::Class<'a>;
499
500    /// The [`Style`] of a class with the given status.
501    fn style(&self, class: &Self::Class<'_>, status: Status) -> Style;
502}
503
504/// A styling function for a [`Radio`].
505pub type StyleFn<'a, Theme> = Box<dyn Fn(&Theme, Status) -> Style + 'a>;
506
507impl Catalog for Theme {
508    type Class<'a> = StyleFn<'a, Self>;
509
510    fn default<'a>() -> Self::Class<'a> {
511        Box::new(default)
512    }
513
514    fn style(&self, class: &Self::Class<'_>, status: Status) -> Style {
515        class(self, status)
516    }
517}
518
519/// The default style of a [`Radio`] button.
520pub fn default(theme: &Theme, status: Status) -> Style {
521    let palette = theme.extended_palette();
522
523    let active = Style {
524        background: Color::TRANSPARENT.into(),
525        dot_color: palette.primary.strong.color,
526        border_width: 1.0,
527        border_color: palette.primary.strong.color,
528        text_color: None,
529    };
530
531    match status {
532        Status::Active { .. } => active,
533        Status::Hovered { .. } => Style {
534            dot_color: palette.primary.strong.color,
535            background: palette.primary.weak.color.into(),
536            ..active
537        },
538    }
539}
iced_widget/radio.rs

iced_widget/
radio.rs
