iced_widget/
row.rs

1//! Distribute content horizontally.
2use crate::core::alignment::{self, Alignment};
3use crate::core::layout::{self, Layout};
4use crate::core::mouse;
5use crate::core::overlay;
6use crate::core::renderer;
7use crate::core::widget::{Operation, Tree};
8use crate::core::{
9    Clipboard, Element, Event, Length, Padding, Pixels, Rectangle, Shell, Size,
10    Vector, Widget,
11};
12
13/// A container that distributes its contents horizontally.
14///
15/// # Example
16/// ```no_run
17/// # mod iced { pub mod widget { pub use iced_widget::*; } }
18/// # pub type State = ();
19/// # pub type Element<'a, Message> = iced_widget::core::Element<'a, Message, iced_widget::Theme, iced_widget::Renderer>;
20/// use iced::widget::{button, row};
21///
22/// #[derive(Debug, Clone)]
23/// enum Message {
24///     // ...
25/// }
26///
27/// fn view(state: &State) -> Element<'_, Message> {
28///     row![
29///         "I am to the left!",
30///         button("I am in the middle!"),
31///         "I am to the right!",
32///     ].into()
33/// }
34/// ```
35#[allow(missing_debug_implementations)]
36pub struct Row<'a, Message, Theme = crate::Theme, Renderer = crate::Renderer> {
37    spacing: f32,
38    padding: Padding,
39    width: Length,
40    height: Length,
41    align: Alignment,
42    clip: bool,
43    children: Vec<Element<'a, Message, Theme, Renderer>>,
44}
45
46impl<'a, Message, Theme, Renderer> Row<'a, Message, Theme, Renderer>
47where
48    Renderer: crate::core::Renderer,
49{
50    /// Creates an empty [`Row`].
51    pub fn new() -> Self {
52        Self::from_vec(Vec::new())
53    }
54
55    /// Creates a [`Row`] with the given capacity.
56    pub fn with_capacity(capacity: usize) -> Self {
57        Self::from_vec(Vec::with_capacity(capacity))
58    }
59
60    /// Creates a [`Row`] with the given elements.
61    pub fn with_children(
62        children: impl IntoIterator<Item = Element<'a, Message, Theme, Renderer>>,
63    ) -> Self {
64        let iterator = children.into_iter();
65
66        Self::with_capacity(iterator.size_hint().0).extend(iterator)
67    }
68
69    /// Creates a [`Row`] from an already allocated [`Vec`].
70    ///
71    /// Keep in mind that the [`Row`] will not inspect the [`Vec`], which means
72    /// it won't automatically adapt to the sizing strategy of its contents.
73    ///
74    /// If any of the children have a [`Length::Fill`] strategy, you will need to
75    /// call [`Row::width`] or [`Row::height`] accordingly.
76    pub fn from_vec(
77        children: Vec<Element<'a, Message, Theme, Renderer>>,
78    ) -> Self {
79        Self {
80            spacing: 0.0,
81            padding: Padding::ZERO,
82            width: Length::Shrink,
83            height: Length::Shrink,
84            align: Alignment::Start,
85            clip: false,
86            children,
87        }
88    }
89
90    /// Sets the horizontal spacing _between_ elements.
91    ///
92    /// Custom margins per element do not exist in iced. You should use this
93    /// method instead! While less flexible, it helps you keep spacing between
94    /// elements consistent.
95    pub fn spacing(mut self, amount: impl Into<Pixels>) -> Self {
96        self.spacing = amount.into().0;
97        self
98    }
99
100    /// Sets the [`Padding`] of the [`Row`].
101    pub fn padding<P: Into<Padding>>(mut self, padding: P) -> Self {
102        self.padding = padding.into();
103        self
104    }
105
106    /// Sets the width of the [`Row`].
107    pub fn width(mut self, width: impl Into<Length>) -> Self {
108        self.width = width.into();
109        self
110    }
111
112    /// Sets the height of the [`Row`].
113    pub fn height(mut self, height: impl Into<Length>) -> Self {
114        self.height = height.into();
115        self
116    }
117
118    /// Sets the vertical alignment of the contents of the [`Row`] .
119    pub fn align_y(mut self, align: impl Into<alignment::Vertical>) -> Self {
120        self.align = Alignment::from(align.into());
121        self
122    }
123
124    /// Sets whether the contents of the [`Row`] should be clipped on
125    /// overflow.
126    pub fn clip(mut self, clip: bool) -> Self {
127        self.clip = clip;
128        self
129    }
130
131    /// Adds an [`Element`] to the [`Row`].
132    pub fn push(
133        mut self,
134        child: impl Into<Element<'a, Message, Theme, Renderer>>,
135    ) -> Self {
136        let child = child.into();
137        let child_size = child.as_widget().size_hint();
138
139        self.width = self.width.enclose(child_size.width);
140        self.height = self.height.enclose(child_size.height);
141
142        self.children.push(child);
143        self
144    }
145
146    /// Adds an element to the [`Row`], if `Some`.
147    pub fn push_maybe(
148        self,
149        child: Option<impl Into<Element<'a, Message, Theme, Renderer>>>,
150    ) -> Self {
151        if let Some(child) = child {
152            self.push(child)
153        } else {
154            self
155        }
156    }
157
158    /// Extends the [`Row`] with the given children.
159    pub fn extend(
160        self,
161        children: impl IntoIterator<Item = Element<'a, Message, Theme, Renderer>>,
162    ) -> Self {
163        children.into_iter().fold(self, Self::push)
164    }
165
166    /// Turns the [`Row`] into a [`Wrapping`] row.
167    ///
168    /// The original alignment of the [`Row`] is preserved per row wrapped.
169    pub fn wrap(self) -> Wrapping<'a, Message, Theme, Renderer> {
170        Wrapping { row: self }
171    }
172}
173
174impl<Message, Renderer> Default for Row<'_, Message, Renderer>
175where
176    Renderer: crate::core::Renderer,
177{
178    fn default() -> Self {
179        Self::new()
180    }
181}
182
183impl<'a, Message, Theme, Renderer: crate::core::Renderer>
184    FromIterator<Element<'a, Message, Theme, Renderer>>
185    for Row<'a, Message, Theme, Renderer>
186{
187    fn from_iter<
188        T: IntoIterator<Item = Element<'a, Message, Theme, Renderer>>,
189    >(
190        iter: T,
191    ) -> Self {
192        Self::with_children(iter)
193    }
194}
195
196impl<Message, Theme, Renderer> Widget<Message, Theme, Renderer>
197    for Row<'_, Message, Theme, Renderer>
198where
199    Renderer: crate::core::Renderer,
200{
201    fn children(&self) -> Vec<Tree> {
202        self.children.iter().map(Tree::new).collect()
203    }
204
205    fn diff(&self, tree: &mut Tree) {
206        tree.diff_children(&self.children);
207    }
208
209    fn size(&self) -> Size<Length> {
210        Size {
211            width: self.width,
212            height: self.height,
213        }
214    }
215
216    fn layout(
217        &self,
218        tree: &mut Tree,
219        renderer: &Renderer,
220        limits: &layout::Limits,
221    ) -> layout::Node {
222        layout::flex::resolve(
223            layout::flex::Axis::Horizontal,
224            renderer,
225            limits,
226            self.width,
227            self.height,
228            self.padding,
229            self.spacing,
230            self.align,
231            &self.children,
232            &mut tree.children,
233        )
234    }
235
236    fn operate(
237        &self,
238        tree: &mut Tree,
239        layout: Layout<'_>,
240        renderer: &Renderer,
241        operation: &mut dyn Operation,
242    ) {
243        operation.container(None, layout.bounds(), &mut |operation| {
244            self.children
245                .iter()
246                .zip(&mut tree.children)
247                .zip(layout.children())
248                .for_each(|((child, state), layout)| {
249                    child
250                        .as_widget()
251                        .operate(state, layout, renderer, operation);
252                });
253        });
254    }
255
256    fn update(
257        &mut self,
258        tree: &mut Tree,
259        event: &Event,
260        layout: Layout<'_>,
261        cursor: mouse::Cursor,
262        renderer: &Renderer,
263        clipboard: &mut dyn Clipboard,
264        shell: &mut Shell<'_, Message>,
265        viewport: &Rectangle,
266    ) {
267        for ((child, state), layout) in self
268            .children
269            .iter_mut()
270            .zip(&mut tree.children)
271            .zip(layout.children())
272        {
273            child.as_widget_mut().update(
274                state, event, layout, cursor, renderer, clipboard, shell,
275                viewport,
276            );
277        }
278    }
279
280    fn mouse_interaction(
281        &self,
282        tree: &Tree,
283        layout: Layout<'_>,
284        cursor: mouse::Cursor,
285        viewport: &Rectangle,
286        renderer: &Renderer,
287    ) -> mouse::Interaction {
288        self.children
289            .iter()
290            .zip(&tree.children)
291            .zip(layout.children())
292            .map(|((child, state), layout)| {
293                child.as_widget().mouse_interaction(
294                    state, layout, cursor, viewport, renderer,
295                )
296            })
297            .max()
298            .unwrap_or_default()
299    }
300
301    fn draw(
302        &self,
303        tree: &Tree,
304        renderer: &mut Renderer,
305        theme: &Theme,
306        style: &renderer::Style,
307        layout: Layout<'_>,
308        cursor: mouse::Cursor,
309        viewport: &Rectangle,
310    ) {
311        if let Some(clipped_viewport) = layout.bounds().intersection(viewport) {
312            let viewport = if self.clip {
313                &clipped_viewport
314            } else {
315                viewport
316            };
317
318            for ((child, state), layout) in self
319                .children
320                .iter()
321                .zip(&tree.children)
322                .zip(layout.children())
323                .filter(|(_, layout)| layout.bounds().intersects(viewport))
324            {
325                child.as_widget().draw(
326                    state, renderer, theme, style, layout, cursor, viewport,
327                );
328            }
329        }
330    }
331
332    fn overlay<'b>(
333        &'b mut self,
334        tree: &'b mut Tree,
335        layout: Layout<'_>,
336        renderer: &Renderer,
337        translation: Vector,
338    ) -> Option<overlay::Element<'b, Message, Theme, Renderer>> {
339        overlay::from_children(
340            &mut self.children,
341            tree,
342            layout,
343            renderer,
344            translation,
345        )
346    }
347}
348
349impl<'a, Message, Theme, Renderer> From<Row<'a, Message, Theme, Renderer>>
350    for Element<'a, Message, Theme, Renderer>
351where
352    Message: 'a,
353    Theme: 'a,
354    Renderer: crate::core::Renderer + 'a,
355{
356    fn from(row: Row<'a, Message, Theme, Renderer>) -> Self {
357        Self::new(row)
358    }
359}
360
361/// A [`Row`] that wraps its contents.
362///
363/// Create a [`Row`] first, and then call [`Row::wrap`] to
364/// obtain a [`Row`] that wraps its contents.
365///
366/// The original alignment of the [`Row`] is preserved per row wrapped.
367#[allow(missing_debug_implementations)]
368pub struct Wrapping<
369    'a,
370    Message,
371    Theme = crate::Theme,
372    Renderer = crate::Renderer,
373> {
374    row: Row<'a, Message, Theme, Renderer>,
375}
376
377impl<Message, Theme, Renderer> Widget<Message, Theme, Renderer>
378    for Wrapping<'_, Message, Theme, Renderer>
379where
380    Renderer: crate::core::Renderer,
381{
382    fn children(&self) -> Vec<Tree> {
383        self.row.children()
384    }
385
386    fn diff(&self, tree: &mut Tree) {
387        self.row.diff(tree);
388    }
389
390    fn size(&self) -> Size<Length> {
391        self.row.size()
392    }
393
394    fn layout(
395        &self,
396        tree: &mut Tree,
397        renderer: &Renderer,
398        limits: &layout::Limits,
399    ) -> layout::Node {
400        let limits = limits
401            .width(self.row.width)
402            .height(self.row.height)
403            .shrink(self.row.padding);
404
405        let spacing = self.row.spacing;
406        let max_width = limits.max().width;
407
408        let mut children: Vec<layout::Node> = Vec::new();
409        let mut intrinsic_size = Size::ZERO;
410        let mut row_start = 0;
411        let mut row_height = 0.0;
412        let mut x = 0.0;
413        let mut y = 0.0;
414
415        let align_factor = match self.row.align {
416            Alignment::Start => 0.0,
417            Alignment::Center => 2.0,
418            Alignment::End => 1.0,
419        };
420
421        let align = |row_start: std::ops::Range<usize>,
422                     row_height: f32,
423                     children: &mut Vec<layout::Node>| {
424            if align_factor != 0.0 {
425                for node in &mut children[row_start] {
426                    let height = node.size().height;
427
428                    node.translate_mut(Vector::new(
429                        0.0,
430                        (row_height - height) / align_factor,
431                    ));
432                }
433            }
434        };
435
436        for (i, child) in self.row.children.iter().enumerate() {
437            let node = child.as_widget().layout(
438                &mut tree.children[i],
439                renderer,
440                &limits,
441            );
442
443            let child_size = node.size();
444
445            if x != 0.0 && x + child_size.width > max_width {
446                intrinsic_size.width = intrinsic_size.width.max(x - spacing);
447
448                align(row_start..i, row_height, &mut children);
449
450                y += row_height + spacing;
451                x = 0.0;
452                row_start = i;
453                row_height = 0.0;
454            }
455
456            row_height = row_height.max(child_size.height);
457
458            children.push(node.move_to((
459                x + self.row.padding.left,
460                y + self.row.padding.top,
461            )));
462
463            x += child_size.width + spacing;
464        }
465
466        if x != 0.0 {
467            intrinsic_size.width = intrinsic_size.width.max(x - spacing);
468        }
469
470        intrinsic_size.height = y + row_height;
471        align(row_start..children.len(), row_height, &mut children);
472
473        let size =
474            limits.resolve(self.row.width, self.row.height, intrinsic_size);
475
476        layout::Node::with_children(size.expand(self.row.padding), children)
477    }
478
479    fn operate(
480        &self,
481        tree: &mut Tree,
482        layout: Layout<'_>,
483        renderer: &Renderer,
484        operation: &mut dyn Operation,
485    ) {
486        self.row.operate(tree, layout, renderer, operation);
487    }
488
489    fn update(
490        &mut self,
491        tree: &mut Tree,
492        event: &Event,
493        layout: Layout<'_>,
494        cursor: mouse::Cursor,
495        renderer: &Renderer,
496        clipboard: &mut dyn Clipboard,
497        shell: &mut Shell<'_, Message>,
498        viewport: &Rectangle,
499    ) {
500        self.row.update(
501            tree, event, layout, cursor, renderer, clipboard, shell, viewport,
502        );
503    }
504
505    fn mouse_interaction(
506        &self,
507        tree: &Tree,
508        layout: Layout<'_>,
509        cursor: mouse::Cursor,
510        viewport: &Rectangle,
511        renderer: &Renderer,
512    ) -> mouse::Interaction {
513        self.row
514            .mouse_interaction(tree, layout, cursor, viewport, renderer)
515    }
516
517    fn draw(
518        &self,
519        tree: &Tree,
520        renderer: &mut Renderer,
521        theme: &Theme,
522        style: &renderer::Style,
523        layout: Layout<'_>,
524        cursor: mouse::Cursor,
525        viewport: &Rectangle,
526    ) {
527        self.row
528            .draw(tree, renderer, theme, style, layout, cursor, viewport);
529    }
530
531    fn overlay<'b>(
532        &'b mut self,
533        tree: &'b mut Tree,
534        layout: Layout<'_>,
535        renderer: &Renderer,
536        translation: Vector,
537    ) -> Option<overlay::Element<'b, Message, Theme, Renderer>> {
538        self.row.overlay(tree, layout, renderer, translation)
539    }
540}
541
542impl<'a, Message, Theme, Renderer> From<Wrapping<'a, Message, Theme, Renderer>>
543    for Element<'a, Message, Theme, Renderer>
544where
545    Message: 'a,
546    Theme: 'a,
547    Renderer: crate::core::Renderer + 'a,
548{
549    fn from(row: Wrapping<'a, Message, Theme, Renderer>) -> Self {
550        Self::new(row)
551    }
552}
iced_widget/row.rs

iced_widget/
row.rs
