cosmic/widget/dropdown/
widget.rs

1// Copyright 2023 System76 <info@system76.com>
2// Copyright 2019 Héctor Ramón, Iced contributors
3// SPDX-License-Identifier: MPL-2.0 AND MIT
4
5use super::menu::{self, Menu};
6use crate::widget::icon::{self, Handle};
7use crate::{Element, surface};
8use derive_setters::Setters;
9use iced::window;
10use iced_core::event::{self, Event};
11use iced_core::text::{self, Paragraph, Text};
12use iced_core::widget::tree::{self, Tree};
13use iced_core::{
14    Clipboard, Layout, Length, Padding, Pixels, Rectangle, Shell, Size, Vector, Widget,
15};
16use iced_core::{Shadow, alignment, keyboard, layout, mouse, overlay, renderer, svg, touch};
17use iced_widget::pick_list::{self, Catalog};
18use std::borrow::Cow;
19use std::ffi::OsStr;
20use std::hash::{DefaultHasher, Hash, Hasher};
21use std::marker::PhantomData;
22use std::sync::atomic::{AtomicBool, Ordering};
23use std::sync::{Arc, LazyLock, Mutex};
24
25pub type DropdownView<Message> = Arc<dyn Fn() -> Element<'static, Message> + Send + Sync>;
26static AUTOSIZE_ID: LazyLock<crate::widget::Id> =
27    LazyLock::new(|| crate::widget::Id::new("cosmic-applet-autosize"));
28/// A widget for selecting a single value from a list of selections.
29#[derive(Setters)]
30pub struct Dropdown<'a, S: AsRef<str> + Send + Sync + Clone + 'static, Message, AppMessage>
31where
32    [S]: std::borrow::ToOwned,
33{
34    #[setters(skip)]
35    on_selected: Arc<dyn Fn(usize) -> Message + Send + Sync>,
36    #[setters(skip)]
37    selections: Cow<'a, [S]>,
38    #[setters]
39    icons: Cow<'a, [icon::Handle]>,
40    #[setters(skip)]
41    selected: Option<usize>,
42    #[setters(into)]
43    width: Length,
44    gap: f32,
45    #[setters(into)]
46    padding: Padding,
47    #[setters(strip_option)]
48    text_size: Option<f32>,
49    text_line_height: text::LineHeight,
50    #[setters(strip_option)]
51    font: Option<crate::font::Font>,
52    #[setters(skip)]
53    on_surface_action: Option<Arc<dyn Fn(surface::Action) -> Message + Send + Sync + 'static>>,
54    #[setters(skip)]
55    action_map: Option<Arc<dyn Fn(Message) -> AppMessage + 'static + Send + Sync>>,
56    #[setters(strip_option)]
57    window_id: Option<window::Id>,
58    #[cfg(all(feature = "winit", feature = "wayland"))]
59    positioner: iced_runtime::platform_specific::wayland::popup::SctkPositioner,
60}
61
62impl<'a, S: AsRef<str> + Send + Sync + Clone + 'static, Message: 'static, AppMessage: 'static>
63    Dropdown<'a, S, Message, AppMessage>
64where
65    [S]: std::borrow::ToOwned,
66{
67    /// The default gap.
68    pub const DEFAULT_GAP: f32 = 4.0;
69
70    /// The default padding.
71    pub const DEFAULT_PADDING: Padding = Padding::new(8.0);
72
73    /// Creates a new [`Dropdown`] with the given list of selections, the current
74    /// selected value, and the message to produce when an option is selected.
75    pub fn new(
76        selections: Cow<'a, [S]>,
77        selected: Option<usize>,
78        on_selected: impl Fn(usize) -> Message + 'static + Send + Sync,
79    ) -> Self {
80        Self {
81            on_selected: Arc::new(on_selected),
82            selections,
83            icons: Cow::Borrowed(&[]),
84            selected,
85            width: Length::Shrink,
86            gap: Self::DEFAULT_GAP,
87            padding: Self::DEFAULT_PADDING,
88            text_size: None,
89            text_line_height: text::LineHeight::Relative(1.2),
90            font: None,
91            window_id: None,
92            #[cfg(all(feature = "winit", feature = "wayland"))]
93            positioner: iced_runtime::platform_specific::wayland::popup::SctkPositioner::default(),
94            on_surface_action: None,
95            action_map: None,
96        }
97    }
98
99    #[cfg(all(feature = "winit", feature = "wayland"))]
100    /// Handle dropdown requests for popup creation.
101    /// Intended to be used with [`crate::app::message::get_popup`]
102    pub fn with_popup<NewAppMessage>(
103        mut self,
104        parent_id: window::Id,
105        on_surface_action: impl Fn(surface::Action) -> Message + Send + Sync + 'static,
106        action_map: impl Fn(Message) -> NewAppMessage + Send + Sync + 'static,
107    ) -> Dropdown<'a, S, Message, NewAppMessage> {
108        let Self {
109            on_selected,
110            selections,
111            icons,
112            selected,
113            width,
114            gap,
115            padding,
116            text_size,
117            text_line_height,
118            font,
119            positioner,
120            ..
121        } = self;
122
123        Dropdown::<'a, S, Message, NewAppMessage> {
124            on_selected,
125            selections,
126            icons,
127            selected,
128            width,
129            gap,
130            padding,
131            text_size,
132            text_line_height,
133            font,
134            on_surface_action: Some(Arc::new(on_surface_action)),
135            action_map: Some(Arc::new(action_map)),
136            window_id: Some(parent_id),
137            positioner,
138        }
139    }
140
141    #[cfg(all(feature = "winit", feature = "wayland"))]
142    pub fn with_positioner(
143        mut self,
144        positioner: iced_runtime::platform_specific::wayland::popup::SctkPositioner,
145    ) -> Self {
146        self.positioner = positioner;
147        self
148    }
149}
150
151impl<
152    S: AsRef<str> + Send + Sync + Clone + 'static,
153    Message: 'static + Clone,
154    AppMessage: 'static + Clone,
155> Widget<Message, crate::Theme, crate::Renderer> for Dropdown<'_, S, Message, AppMessage>
156where
157    [S]: std::borrow::ToOwned,
158{
159    fn tag(&self) -> tree::Tag {
160        tree::Tag::of::<State>()
161    }
162
163    fn state(&self) -> tree::State {
164        tree::State::new(State::new())
165    }
166
167    fn diff(&mut self, tree: &mut Tree) {
168        let state = tree.state.downcast_mut::<State>();
169
170        state
171            .selections
172            .resize_with(self.selections.len(), crate::Plain::default);
173        state.hashes.resize(self.selections.len(), 0);
174
175        for (i, selection) in self.selections.iter().enumerate() {
176            let mut hasher = DefaultHasher::new();
177            selection.as_ref().hash(&mut hasher);
178            let text_hash = hasher.finish();
179
180            if state.hashes[i] == text_hash {
181                continue;
182            }
183
184            state.hashes[i] = text_hash;
185            state.selections[i].update(Text {
186                content: selection.as_ref(),
187                bounds: Size::INFINITY,
188                // TODO use the renderer default size
189                size: iced::Pixels(self.text_size.unwrap_or(14.0)),
190                line_height: self.text_line_height,
191                font: self.font.unwrap_or_else(crate::font::default),
192                horizontal_alignment: alignment::Horizontal::Left,
193                vertical_alignment: alignment::Vertical::Top,
194                shaping: text::Shaping::Advanced,
195                wrapping: text::Wrapping::default(),
196            });
197        }
198    }
199
200    fn size(&self) -> Size<Length> {
201        Size::new(self.width, Length::Shrink)
202    }
203
204    fn layout(
205        &self,
206        tree: &mut Tree,
207        renderer: &crate::Renderer,
208        limits: &layout::Limits,
209    ) -> layout::Node {
210        layout(
211            renderer,
212            limits,
213            self.width,
214            self.gap,
215            self.padding,
216            self.text_size.unwrap_or(14.0),
217            self.text_line_height,
218            self.font,
219            self.selected.and_then(|id| {
220                self.selections
221                    .get(id)
222                    .map(AsRef::as_ref)
223                    .zip(tree.state.downcast_mut::<State>().selections.get_mut(id))
224            }),
225            !self.icons.is_empty(),
226        )
227    }
228
229    fn on_event(
230        &mut self,
231        tree: &mut Tree,
232        event: Event,
233        layout: Layout<'_>,
234        cursor: mouse::Cursor,
235        _renderer: &crate::Renderer,
236        _clipboard: &mut dyn Clipboard,
237        shell: &mut Shell<'_, Message>,
238        _viewport: &Rectangle,
239    ) -> event::Status {
240        update::<S, Message, AppMessage>(
241            &event,
242            layout,
243            cursor,
244            shell,
245            #[cfg(all(feature = "winit", feature = "wayland"))]
246            self.positioner.clone(),
247            self.on_selected.clone(),
248            self.selected,
249            &self.selections,
250            || tree.state.downcast_mut::<State>(),
251            self.window_id,
252            self.on_surface_action.clone(),
253            self.action_map.clone(),
254            &self.icons,
255            self.gap,
256            self.padding,
257            self.text_size,
258            self.font,
259            self.selected,
260        )
261    }
262
263    fn mouse_interaction(
264        &self,
265        _tree: &Tree,
266        layout: Layout<'_>,
267        cursor: mouse::Cursor,
268        _viewport: &Rectangle,
269        _renderer: &crate::Renderer,
270    ) -> mouse::Interaction {
271        mouse_interaction(layout, cursor)
272    }
273
274    fn draw(
275        &self,
276        tree: &Tree,
277        renderer: &mut crate::Renderer,
278        theme: &crate::Theme,
279        _style: &iced_core::renderer::Style,
280        layout: Layout<'_>,
281        cursor: mouse::Cursor,
282        viewport: &Rectangle,
283    ) {
284        let font = self.font.unwrap_or_else(crate::font::default);
285        draw(
286            renderer,
287            theme,
288            layout,
289            cursor,
290            self.gap,
291            self.padding,
292            self.text_size,
293            self.text_line_height,
294            font,
295            self.selected.and_then(|id| self.selections.get(id)),
296            self.selected.and_then(|id| self.icons.get(id)),
297            tree.state.downcast_ref::<State>(),
298            viewport,
299        );
300    }
301
302    fn overlay<'b>(
303        &'b mut self,
304        tree: &'b mut Tree,
305        layout: Layout<'_>,
306        renderer: &crate::Renderer,
307        translation: Vector,
308    ) -> Option<overlay::Element<'b, Message, crate::Theme, crate::Renderer>> {
309        #[cfg(all(feature = "winit", feature = "wayland"))]
310        if self.window_id.is_some() || self.on_surface_action.is_some() {
311            return None;
312        }
313
314        let state = tree.state.downcast_mut::<State>();
315
316        overlay(
317            layout,
318            renderer,
319            state,
320            self.gap,
321            self.padding,
322            self.text_size.unwrap_or(14.0),
323            self.text_line_height,
324            self.font,
325            &self.selections,
326            &self.icons,
327            self.selected,
328            self.on_selected.as_ref(),
329            translation,
330            None,
331        )
332    }
333
334    // #[cfg(feature = "a11y")]
335    // /// get the a11y nodes for the widget
336    // fn a11y_nodes(
337    //     &self,
338    //     layout: Layout<'_>,
339    //     state: &Tree,
340    //     p: mouse::Cursor,
341    // ) -> iced_accessibility::A11yTree {
342    //     // TODO
343    // }
344}
345
346impl<
347    'a,
348    S: AsRef<str> + Send + Sync + Clone + 'static,
349    Message: 'static + std::clone::Clone,
350    AppMessage: 'static + std::clone::Clone,
351> From<Dropdown<'a, S, Message, AppMessage>> for crate::Element<'a, Message>
352where
353    [S]: std::borrow::ToOwned,
354{
355    fn from(pick_list: Dropdown<'a, S, Message, AppMessage>) -> Self {
356        Self::new(pick_list)
357    }
358}
359
360/// The local state of a [`Dropdown`].
361#[derive(Debug, Clone)]
362pub struct State {
363    icon: Option<svg::Handle>,
364    menu: menu::State,
365    keyboard_modifiers: keyboard::Modifiers,
366    is_open: Arc<AtomicBool>,
367    hovered_option: Arc<Mutex<Option<usize>>>,
368    hashes: Vec<u64>,
369    selections: Vec<crate::Plain>,
370    popup_id: window::Id,
371}
372
373impl State {
374    /// Creates a new [`State`] for a [`Dropdown`].
375    pub fn new() -> Self {
376        Self {
377            icon: match icon::from_name("pan-down-symbolic").size(16).handle().data {
378                icon::Data::Name(named) => named
379                    .path()
380                    .filter(|path| path.extension().is_some_and(|ext| ext == OsStr::new("svg")))
381                    .map(iced_core::svg::Handle::from_path),
382                icon::Data::Svg(handle) => Some(handle),
383                icon::Data::Image(_) => None,
384            },
385            menu: menu::State::default(),
386            keyboard_modifiers: keyboard::Modifiers::default(),
387            is_open: Arc::new(AtomicBool::new(false)),
388            hovered_option: Arc::new(Mutex::new(None)),
389            selections: Vec::new(),
390            hashes: Vec::new(),
391            popup_id: window::Id::unique(),
392        }
393    }
394}
395
396impl Default for State {
397    fn default() -> Self {
398        Self::new()
399    }
400}
401
402/// Computes the layout of a [`Dropdown`].
403#[allow(clippy::too_many_arguments)]
404pub fn layout(
405    renderer: &crate::Renderer,
406    limits: &layout::Limits,
407    width: Length,
408    gap: f32,
409    padding: Padding,
410    text_size: f32,
411    text_line_height: text::LineHeight,
412    font: Option<crate::font::Font>,
413    selection: Option<(&str, &mut crate::Plain)>,
414    has_icons: bool,
415) -> layout::Node {
416    use std::f32;
417
418    let limits = limits.width(width).height(Length::Shrink).shrink(padding);
419
420    let max_width = match width {
421        Length::Shrink => {
422            let measure = move |(label, paragraph): (_, &mut crate::Plain)| -> f32 {
423                paragraph.update(Text {
424                    content: label,
425                    bounds: Size::new(f32::MAX, f32::MAX),
426                    size: iced::Pixels(text_size),
427                    line_height: text_line_height,
428                    font: font.unwrap_or_else(crate::font::default),
429                    horizontal_alignment: alignment::Horizontal::Left,
430                    vertical_alignment: alignment::Vertical::Top,
431                    shaping: text::Shaping::Advanced,
432                    wrapping: text::Wrapping::default(),
433                });
434                paragraph.min_width().round()
435            };
436
437            selection.map(measure).unwrap_or_default()
438        }
439        _ => 0.0,
440    };
441
442    let icon_size = if has_icons { 24.0 } else { 0.0 };
443
444    let size = {
445        let intrinsic = Size::new(
446            max_width + icon_size + gap + 16.0,
447            f32::from(text_line_height.to_absolute(Pixels(text_size))),
448        );
449
450        limits
451            .resolve(width, Length::Shrink, intrinsic)
452            .expand(padding)
453    };
454
455    layout::Node::new(size)
456}
457
458/// Processes an [`Event`] and updates the [`State`] of a [`Dropdown`]
459/// accordingly.
460#[allow(clippy::too_many_arguments, clippy::too_many_lines)]
461pub fn update<
462    'a,
463    S: AsRef<str> + Send + Sync + Clone + 'static,
464    Message: Clone + 'static,
465    AppMessage: Clone + 'static,
466>(
467    event: &Event,
468    layout: Layout<'_>,
469    cursor: mouse::Cursor,
470    shell: &mut Shell<'_, Message>,
471    #[cfg(all(feature = "winit", feature = "wayland"))]
472    positioner: iced_runtime::platform_specific::wayland::popup::SctkPositioner,
473    on_selected: Arc<dyn Fn(usize) -> Message + Send + Sync + 'static>,
474    selected: Option<usize>,
475    selections: &[S],
476    state: impl FnOnce() -> &'a mut State,
477    _window_id: Option<window::Id>,
478    on_surface_action: Option<Arc<dyn Fn(surface::Action) -> Message + Send + Sync + 'static>>,
479    action_map: Option<Arc<dyn Fn(Message) -> AppMessage + Send + Sync + 'static>>,
480    icons: &[icon::Handle],
481    gap: f32,
482    padding: Padding,
483    text_size: Option<f32>,
484    font: Option<crate::font::Font>,
485    selected_option: Option<usize>,
486) -> event::Status {
487    match event {
488        Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
489        | Event::Touch(touch::Event::FingerPressed { .. }) => {
490            let state = state();
491            let is_open = state.is_open.load(Ordering::Relaxed);
492            if is_open {
493                // Event wasn't processed by overlay, so cursor was clicked either outside it's
494                // bounds or on the drop-down, either way we close the overlay.
495                state.is_open.store(false, Ordering::Relaxed);
496                #[cfg(all(feature = "winit", feature = "wayland"))]
497                if let Some(on_close) = on_surface_action {
498                    shell.publish(on_close(surface::action::destroy_popup(state.popup_id)));
499                }
500                event::Status::Captured
501            } else if cursor.is_over(layout.bounds()) {
502                state.is_open.store(true, Ordering::Relaxed);
503                let mut hovered_guard = state.hovered_option.lock().unwrap();
504                *hovered_guard = selected;
505                let id = window::Id::unique();
506                state.popup_id = id;
507                #[cfg(all(feature = "winit", feature = "wayland"))]
508                if let Some(((on_surface_action, parent), action_map)) =
509                    on_surface_action.zip(_window_id).zip(action_map)
510                {
511                    use iced_runtime::platform_specific::wayland::popup::{
512                        SctkPopupSettings, SctkPositioner,
513                    };
514                    let bounds = layout.bounds();
515                    let anchor_rect = Rectangle {
516                        x: bounds.x as i32,
517                        y: bounds.y as i32,
518                        width: bounds.width as i32,
519                        height: bounds.height as i32,
520                    };
521                    let icon_width = if icons.is_empty() { 0.0 } else { 24.0 };
522                    let measure = |_label: &str, selection_paragraph: &crate::Paragraph| -> f32 {
523                        selection_paragraph.min_width().round()
524                    };
525                    let pad_width = padding.horizontal().mul_add(2.0, 16.0);
526
527                    let selections_width = selections
528                        .iter()
529                        .zip(state.selections.iter_mut())
530                        .map(|(label, selection)| measure(label.as_ref(), selection.raw()))
531                        .fold(0.0, |next, current| current.max(next));
532
533                    let icons: Cow<'static, [Handle]> = Cow::Owned(icons.to_vec());
534                    let selections: Cow<'static, [S]> = Cow::Owned(selections.to_vec());
535                    let state = state.clone();
536                    let on_close = surface::action::destroy_popup(id);
537                    let on_surface_action_clone = on_surface_action.clone();
538                    let translation = layout.virtual_offset();
539                    let get_popup_action = surface::action::simple_popup::<AppMessage>(
540                        move || {
541                            SctkPopupSettings {
542                            parent,
543                            id,
544                            input_zone: None,
545                            positioner: SctkPositioner {
546                                size: Some((selections_width as u32 + gap as u32 + pad_width as u32 + icon_width as u32, 10)),
547                                anchor_rect,
548                                // TODO: left or right alignment based on direction?
549                                anchor: cctk::wayland_protocols::xdg::shell::client::xdg_positioner::Anchor::BottomLeft,
550                                gravity: cctk::wayland_protocols::xdg::shell::client::xdg_positioner::Gravity::BottomRight,
551                                reactive: true,
552                                offset: ((-padding.left - translation.x) as i32, -translation.y as i32),
553                                constraint_adjustment: 9,
554                                ..Default::default()
555                            },
556                            parent_size: None,
557                            grab: true,
558                            close_with_children: true,
559                        }
560                        },
561                        Some(Box::new(move || {
562                            let action_map = action_map.clone();
563                            let on_selected = on_selected.clone();
564                            let e: Element<'static, crate::Action<AppMessage>> =
565                                Element::from(menu_widget(
566                                    bounds,
567                                    &state,
568                                    gap,
569                                    padding,
570                                    text_size.unwrap_or(14.0),
571                                    selections.clone(),
572                                    icons.clone(),
573                                    selected_option,
574                                    Arc::new(move |i| on_selected.clone()(i)),
575                                    Some(on_surface_action_clone(on_close.clone())),
576                                ))
577                                .map(move |m| crate::Action::App(action_map.clone()(m)));
578                            e
579                        })),
580                    );
581                    shell.publish(on_surface_action(get_popup_action));
582                }
583                event::Status::Captured
584            } else {
585                event::Status::Ignored
586            }
587        }
588        Event::Mouse(mouse::Event::WheelScrolled {
589            delta: mouse::ScrollDelta::Lines { .. },
590        }) => {
591            let state = state();
592            let is_open = state.is_open.load(Ordering::Relaxed);
593
594            if state.keyboard_modifiers.command() && cursor.is_over(layout.bounds()) && !is_open {
595                let next_index = selected.map(|index| index + 1).unwrap_or_default();
596
597                if selections.len() < next_index {
598                    shell.publish((on_selected)(next_index));
599                }
600
601                event::Status::Captured
602            } else {
603                event::Status::Ignored
604            }
605        }
606        Event::Keyboard(keyboard::Event::ModifiersChanged(modifiers)) => {
607            let state = state();
608
609            state.keyboard_modifiers = *modifiers;
610
611            event::Status::Ignored
612        }
613        _ => event::Status::Ignored,
614    }
615}
616
617/// Returns the current [`mouse::Interaction`] of a [`Dropdown`].
618#[must_use]
619pub fn mouse_interaction(layout: Layout<'_>, cursor: mouse::Cursor) -> mouse::Interaction {
620    let bounds = layout.bounds();
621    let is_mouse_over = cursor.is_over(bounds);
622
623    if is_mouse_over {
624        mouse::Interaction::Pointer
625    } else {
626        mouse::Interaction::default()
627    }
628}
629
630#[cfg(all(feature = "winit", feature = "wayland"))]
631/// Returns the current menu widget of a [`Dropdown`].
632#[allow(clippy::too_many_arguments)]
633pub fn menu_widget<
634    S: AsRef<str> + Send + Sync + Clone + 'static,
635    Message: 'static + std::clone::Clone,
636>(
637    bounds: Rectangle,
638    state: &State,
639    gap: f32,
640    padding: Padding,
641    text_size: f32,
642    selections: Cow<'static, [S]>,
643    icons: Cow<'static, [icon::Handle]>,
644    selected_option: Option<usize>,
645    on_selected: Arc<dyn Fn(usize) -> Message + Send + Sync + 'static>,
646    close_on_selected: Option<Message>,
647) -> crate::Element<'static, Message>
648where
649    [S]: std::borrow::ToOwned,
650{
651    let icon_width = if icons.is_empty() { 0.0 } else { 24.0 };
652    let measure = |_label: &str, selection_paragraph: &crate::Paragraph| -> f32 {
653        selection_paragraph.min_width().round()
654    };
655    let selections_width = selections
656        .iter()
657        .zip(state.selections.iter())
658        .map(|(label, selection)| measure(label.as_ref(), selection.raw()))
659        .fold(0.0, |next, current| current.max(next));
660    let pad_width = padding.horizontal().mul_add(2.0, 16.0);
661
662    let width = selections_width + gap + pad_width + icon_width;
663    let is_open = state.is_open.clone();
664    let menu: Menu<'static, S, Message> = Menu::new(
665        state.menu.clone(),
666        selections,
667        icons,
668        state.hovered_option.clone(),
669        selected_option,
670        move |option| {
671            is_open.store(false, Ordering::Relaxed);
672
673            (on_selected)(option)
674        },
675        None,
676        close_on_selected,
677    )
678    .width(width)
679    .padding(padding)
680    .text_size(text_size);
681
682    crate::widget::autosize::autosize(
683        menu.popup(iced::Point::new(0., 0.), bounds.height),
684        AUTOSIZE_ID.clone(),
685    )
686    .auto_height(true)
687    .auto_width(true)
688    .min_height(1.)
689    .min_width(width)
690    .into()
691}
692
693/// Returns the current overlay of a [`Dropdown`].
694#[allow(clippy::too_many_arguments)]
695pub fn overlay<'a, S: AsRef<str> + Send + Sync + Clone + 'static, Message: std::clone::Clone + 'a>(
696    layout: Layout<'_>,
697    _renderer: &crate::Renderer,
698    state: &'a mut State,
699    gap: f32,
700    padding: Padding,
701    text_size: f32,
702    _text_line_height: text::LineHeight,
703    _font: Option<crate::font::Font>,
704    selections: &'a [S],
705    icons: &'a [icon::Handle],
706    selected_option: Option<usize>,
707    on_selected: &'a dyn Fn(usize) -> Message,
708    translation: Vector,
709    close_on_selected: Option<Message>,
710) -> Option<overlay::Element<'a, Message, crate::Theme, crate::Renderer>>
711where
712    [S]: std::borrow::ToOwned,
713{
714    if state.is_open.load(Ordering::Relaxed) {
715        let bounds = layout.bounds();
716
717        let menu = Menu::new(
718            state.menu.clone(),
719            Cow::Borrowed(selections),
720            Cow::Borrowed(icons),
721            state.hovered_option.clone(),
722            selected_option,
723            |option| {
724                state.is_open.store(false, Ordering::Relaxed);
725
726                (on_selected)(option)
727            },
728            None,
729            close_on_selected,
730        )
731        .width({
732            let measure = |_label: &str, selection_paragraph: &crate::Paragraph| -> f32 {
733                selection_paragraph.min_width().round()
734            };
735
736            let pad_width = padding.horizontal().mul_add(2.0, 16.0);
737
738            let icon_width = if icons.is_empty() { 0.0 } else { 24.0 };
739
740            selections
741                .iter()
742                .zip(state.selections.iter_mut())
743                .map(|(label, selection)| measure(label.as_ref(), selection.raw()))
744                .fold(0.0, |next, current| current.max(next))
745                + gap
746                + pad_width
747                + icon_width
748        })
749        .padding(padding)
750        .text_size(text_size);
751
752        let mut position = layout.position();
753        position.x -= padding.left;
754        position.x += translation.x;
755        position.y += translation.y;
756        Some(menu.overlay(position, bounds.height))
757    } else {
758        None
759    }
760}
761
762/// Draws a [`Dropdown`].
763#[allow(clippy::too_many_arguments)]
764pub fn draw<'a, S>(
765    renderer: &mut crate::Renderer,
766    theme: &crate::Theme,
767    layout: Layout<'_>,
768    cursor: mouse::Cursor,
769    gap: f32,
770    padding: Padding,
771    text_size: Option<f32>,
772    text_line_height: text::LineHeight,
773    font: crate::font::Font,
774    selected: Option<&'a S>,
775    icon: Option<&'a icon::Handle>,
776    state: &'a State,
777    viewport: &Rectangle,
778) where
779    S: AsRef<str> + 'a,
780{
781    let bounds = layout.bounds();
782    let is_mouse_over = cursor.is_over(bounds);
783
784    let style = if is_mouse_over {
785        theme.style(&(), pick_list::Status::Hovered)
786    } else {
787        theme.style(&(), pick_list::Status::Active)
788    };
789
790    iced_core::Renderer::fill_quad(
791        renderer,
792        renderer::Quad {
793            bounds,
794            border: style.border,
795            shadow: Shadow::default(),
796        },
797        style.background,
798    );
799
800    if let Some(handle) = state.icon.clone() {
801        let svg_handle = svg::Svg::new(handle).color(style.text_color);
802
803        svg::Renderer::draw_svg(
804            renderer,
805            svg_handle,
806            Rectangle {
807                x: bounds.x + bounds.width - gap - 16.0,
808                y: bounds.center_y() - 8.0,
809                width: 16.0,
810                height: 16.0,
811            },
812        );
813    }
814
815    if let Some(content) = selected.map(AsRef::as_ref) {
816        let text_size = text_size.unwrap_or_else(|| text::Renderer::default_size(renderer).0);
817
818        let mut bounds = Rectangle {
819            x: bounds.x + padding.left,
820            y: bounds.center_y(),
821            width: bounds.width - padding.horizontal(),
822            height: f32::from(text_line_height.to_absolute(Pixels(text_size))),
823        };
824
825        if let Some(handle) = icon {
826            let icon_bounds = Rectangle {
827                x: bounds.x,
828                y: bounds.y - (bounds.height / 2.0) - 2.0,
829                width: 20.0,
830                height: 20.0,
831            };
832
833            bounds.x += 24.0;
834            icon::draw(renderer, handle, icon_bounds);
835        }
836
837        text::Renderer::fill_text(
838            renderer,
839            Text {
840                content: content.to_string(),
841                size: iced::Pixels(text_size),
842                line_height: text_line_height,
843                font,
844                bounds: bounds.size(),
845                horizontal_alignment: alignment::Horizontal::Left,
846                vertical_alignment: alignment::Vertical::Center,
847                shaping: text::Shaping::Advanced,
848                wrapping: text::Wrapping::default(),
849            },
850            bounds.position(),
851            style.text_color,
852            *viewport,
853        );
854    }
855}
cosmic/widget/dropdown/widget.rs

cosmic/widget/dropdown/
widget.rs
