iced_widget/
rule.rs

1//! Rules divide space horizontally or vertically.
2//!
3//! # Example
4//! ```no_run
5//! # mod iced { pub mod widget { pub use iced_widget::*; } }
6//! # pub type State = ();
7//! # pub type Element<'a, Message> = iced_widget::core::Element<'a, Message, iced_widget::Theme, iced_widget::Renderer>;
8//! use iced::widget::rule;
9//!
10//! #[derive(Clone)]
11//! enum Message {
12//!     // ...,
13//! }
14//!
15//! fn view(state: &State) -> Element<'_, Message> {
16//!     rule::horizontal(2).into()
17//! }
18//! ```
19use crate::core;
20use crate::core::border;
21use crate::core::layout;
22use crate::core::mouse;
23use crate::core::renderer;
24use crate::core::widget::Tree;
25use crate::core::{Color, Element, Layout, Length, Pixels, Rectangle, Size, Theme, Widget};
26
27/// Creates a new horizontal [`Rule`] with the given height.
28pub fn horizontal<'a, Theme>(height: impl Into<Pixels>) -> Rule<'a, Theme>
29where
30    Theme: Catalog,
31{
32    Rule {
33        thickness: Length::Fixed(height.into().0),
34        is_vertical: false,
35        class: Theme::default(),
36    }
37}
38
39/// Creates a new vertical [`Rule`] with the given width.
40pub fn vertical<'a, Theme>(width: impl Into<Pixels>) -> Rule<'a, Theme>
41where
42    Theme: Catalog,
43{
44    Rule {
45        thickness: Length::Fixed(width.into().0),
46        is_vertical: true,
47        class: Theme::default(),
48    }
49}
50
51/// Display a horizontal or vertical rule for dividing content.
52///
53/// # Example
54/// ```no_run
55/// # mod iced { pub mod widget { pub use iced_widget::*; } }
56/// # pub type State = ();
57/// # pub type Element<'a, Message> = iced_widget::core::Element<'a, Message, iced_widget::Theme, iced_widget::Renderer>;
58/// use iced::widget::rule;
59///
60/// #[derive(Clone)]
61/// enum Message {
62///     // ...,
63/// }
64///
65/// fn view(state: &State) -> Element<'_, Message> {
66///     rule::horizontal(2).into()
67/// }
68/// ```
69pub struct Rule<'a, Theme = crate::Theme>
70where
71    Theme: Catalog,
72{
73    thickness: Length,
74    is_vertical: bool,
75    class: Theme::Class<'a>,
76}
77
78impl<'a, Theme> Rule<'a, Theme>
79where
80    Theme: Catalog,
81{
82    /// Sets the style of the [`Rule`].
83    #[must_use]
84    pub fn style(mut self, style: impl Fn(&Theme) -> Style + 'a) -> Self
85    where
86        Theme::Class<'a>: From<StyleFn<'a, Theme>>,
87    {
88        self.class = (Box::new(style) as StyleFn<'a, Theme>).into();
89        self
90    }
91
92    /// Sets the style class of the [`Rule`].
93    #[cfg(feature = "advanced")]
94    #[must_use]
95    pub fn class(mut self, class: impl Into<Theme::Class<'a>>) -> Self {
96        self.class = class.into();
97        self
98    }
99}
100
101impl<Message, Theme, Renderer> Widget<Message, Theme, Renderer> for Rule<'_, Theme>
102where
103    Renderer: core::Renderer,
104    Theme: Catalog,
105{
106    fn size(&self) -> Size<Length> {
107        if self.is_vertical {
108            Size {
109                width: self.thickness,
110                height: Length::Fill,
111            }
112        } else {
113            Size {
114                width: Length::Fill,
115                height: self.thickness,
116            }
117        }
118    }
119
120    fn layout(
121        &mut self,
122        _tree: &mut Tree,
123        _renderer: &Renderer,
124        limits: &layout::Limits,
125    ) -> layout::Node {
126        let size = <Self as Widget<(), Theme, Renderer>>::size(self);
127
128        layout::atomic(limits, size.width, size.height)
129    }
130
131    fn draw(
132        &self,
133        _tree: &Tree,
134        renderer: &mut Renderer,
135        theme: &Theme,
136        _style: &renderer::Style,
137        layout: Layout<'_>,
138        _cursor: mouse::Cursor,
139        _viewport: &Rectangle,
140    ) {
141        let bounds = layout.bounds();
142        let style = theme.style(&self.class);
143
144        let mut bounds = if self.is_vertical {
145            let line_x = bounds.x;
146
147            let (offset, line_height) = style.fill_mode.fill(bounds.height);
148            let line_y = bounds.y + offset;
149
150            Rectangle {
151                x: line_x,
152                y: line_y,
153                width: bounds.width,
154                height: line_height,
155            }
156        } else {
157            let line_y = bounds.y;
158
159            let (offset, line_width) = style.fill_mode.fill(bounds.width);
160            let line_x = bounds.x + offset;
161
162            Rectangle {
163                x: line_x,
164                y: line_y,
165                width: line_width,
166                height: bounds.height,
167            }
168        };
169
170        if style.snap {
171            let unit = 1.0 / renderer.scale_factor().unwrap_or(1.0);
172
173            bounds.width = bounds.width.max(unit);
174            bounds.height = bounds.height.max(unit);
175        }
176
177        renderer.fill_quad(
178            renderer::Quad {
179                bounds,
180                border: border::rounded(style.radius),
181                snap: style.snap,
182                ..renderer::Quad::default()
183            },
184            style.color,
185        );
186    }
187}
188
189impl<'a, Message, Theme, Renderer> From<Rule<'a, Theme>> for Element<'a, Message, Theme, Renderer>
190where
191    Message: 'a,
192    Theme: 'a + Catalog,
193    Renderer: 'a + core::Renderer,
194{
195    fn from(rule: Rule<'a, Theme>) -> Element<'a, Message, Theme, Renderer> {
196        Element::new(rule)
197    }
198}
199
200/// The appearance of a rule.
201#[derive(Debug, Clone, Copy, PartialEq)]
202pub struct Style {
203    /// The color of the rule.
204    pub color: Color,
205    /// The radius of the line corners.
206    pub radius: border::Radius,
207    /// The [`FillMode`] of the rule.
208    pub fill_mode: FillMode,
209    /// Whether the rule should be snapped to the pixel grid.
210    pub snap: bool,
211}
212
213/// The fill mode of a rule.
214#[derive(Debug, Clone, Copy, PartialEq)]
215pub enum FillMode {
216    /// Fill the whole length of the container.
217    Full,
218    /// Fill a percent of the length of the container. The rule
219    /// will be centered in that container.
220    ///
221    /// The range is `[0.0, 100.0]`.
222    Percent(f32),
223    /// Uniform offset from each end, length units.
224    Padded(u16),
225    /// Different offset on each end of the rule, length units.
226    /// First = top or left.
227    AsymmetricPadding(u16, u16),
228}
229
230impl FillMode {
231    /// Return the starting offset and length of the rule.
232    ///
233    /// * `space` - The space to fill.
234    ///
235    /// # Returns
236    ///
237    /// * (`starting_offset`, `length`)
238    pub fn fill(&self, space: f32) -> (f32, f32) {
239        match *self {
240            FillMode::Full => (0.0, space),
241            FillMode::Percent(percent) => {
242                if percent >= 100.0 {
243                    (0.0, space)
244                } else {
245                    let percent_width = (space * percent / 100.0).round();
246
247                    (((space - percent_width) / 2.0).round(), percent_width)
248                }
249            }
250            FillMode::Padded(padding) => {
251                if padding == 0 {
252                    (0.0, space)
253                } else {
254                    let padding = padding as f32;
255                    let mut line_width = space - (padding * 2.0);
256                    if line_width < 0.0 {
257                        line_width = 0.0;
258                    }
259
260                    (padding, line_width)
261                }
262            }
263            FillMode::AsymmetricPadding(first_pad, second_pad) => {
264                let first_pad = first_pad as f32;
265                let second_pad = second_pad as f32;
266                let mut line_width = space - first_pad - second_pad;
267                if line_width < 0.0 {
268                    line_width = 0.0;
269                }
270
271                (first_pad, line_width)
272            }
273        }
274    }
275}
276
277/// The theme catalog of a [`Rule`].
278pub trait Catalog: Sized {
279    /// The item class of the [`Catalog`].
280    type Class<'a>;
281
282    /// The default class produced by the [`Catalog`].
283    fn default<'a>() -> Self::Class<'a>;
284
285    /// The [`Style`] of a class with the given status.
286    fn style(&self, class: &Self::Class<'_>) -> Style;
287}
288
289/// A styling function for a [`Rule`].
290///
291/// This is just a boxed closure: `Fn(&Theme, Status) -> Style`.
292pub type StyleFn<'a, Theme> = Box<dyn Fn(&Theme) -> Style + 'a>;
293
294impl Catalog for Theme {
295    type Class<'a> = StyleFn<'a, Self>;
296
297    fn default<'a>() -> Self::Class<'a> {
298        Box::new(default)
299    }
300
301    fn style(&self, class: &Self::Class<'_>) -> Style {
302        class(self)
303    }
304}
305
306/// The default styling of a [`Rule`].
307pub fn default(theme: &Theme) -> Style {
308    let palette = theme.extended_palette();
309
310    Style {
311        color: palette.background.strong.color,
312        radius: 0.0.into(),
313        fill_mode: FillMode::Full,
314        snap: true,
315    }
316}
317
318/// A [`Rule`] styling using the weak background color.
319pub fn weak(theme: &Theme) -> Style {
320    let palette = theme.extended_palette();
321
322    Style {
323        color: palette.background.weak.color,
324        radius: 0.0.into(),
325        fill_mode: FillMode::Full,
326        snap: true,
327    }
328}
iced_widget/rule.rs

iced_widget/
rule.rs
