1use crate::{
2 elements::*,
3 platform::{CursorStyle, MouseButton},
4 AppContext, Entity, View, ViewContext, WeakViewHandle,
5};
6
7pub struct Select {
8 handle: WeakViewHandle<Self>,
9 render_item: Box<dyn Fn(usize, ItemType, bool, &mut ViewContext<Select>) -> AnyElement<Self>>,
10 selected_item_ix: usize,
11 item_count: usize,
12 is_open: bool,
13 list_state: UniformListState,
14 build_style: Option<Box<dyn FnMut(&mut AppContext) -> SelectStyle>>,
15}
16
17#[derive(Clone, Default)]
18pub struct SelectStyle {
19 pub header: ContainerStyle,
20 pub menu: ContainerStyle,
21}
22
23pub enum ItemType {
24 Header,
25 Selected,
26 Unselected,
27}
28
29pub enum Event {}
30
31impl Select {
32 pub fn new<
33 F: 'static + Fn(usize, ItemType, bool, &mut ViewContext<Self>) -> AnyElement<Self>,
34 >(
35 item_count: usize,
36 cx: &mut ViewContext<Self>,
37 render_item: F,
38 ) -> Self {
39 Self {
40 handle: cx.weak_handle(),
41 render_item: Box::new(render_item),
42 selected_item_ix: 0,
43 item_count,
44 is_open: false,
45 list_state: UniformListState::default(),
46 build_style: Default::default(),
47 }
48 }
49
50 pub fn with_style(mut self, f: impl 'static + FnMut(&mut AppContext) -> SelectStyle) -> Self {
51 self.build_style = Some(Box::new(f));
52 self
53 }
54
55 pub fn set_item_count(&mut self, count: usize, cx: &mut ViewContext<Self>) {
56 self.item_count = count;
57 cx.notify();
58 }
59
60 fn toggle(&mut self, cx: &mut ViewContext<Self>) {
61 self.is_open = !self.is_open;
62 cx.notify();
63 }
64
65 pub fn set_selected_index(&mut self, ix: usize, cx: &mut ViewContext<Self>) {
66 self.selected_item_ix = ix;
67 self.is_open = false;
68 cx.notify();
69 }
70
71 pub fn selected_index(&self) -> usize {
72 self.selected_item_ix
73 }
74}
75
76impl Entity for Select {
77 type Event = Event;
78}
79
80impl View for Select {
81 fn ui_name() -> &'static str {
82 "Select"
83 }
84
85 fn render(&mut self, cx: &mut ViewContext<Self>) -> AnyElement<Self> {
86 if self.item_count == 0 {
87 return Empty::new().into_any();
88 }
89
90 enum Header {}
91 enum Item {}
92
93 let style = if let Some(build_style) = self.build_style.as_mut() {
94 (build_style)(cx)
95 } else {
96 Default::default()
97 };
98 let mut result = Flex::column().with_child(
99 MouseEventHandler::new::<Header, _>(self.handle.id(), cx, |mouse_state, cx| {
100 (self.render_item)(
101 self.selected_item_ix,
102 ItemType::Header,
103 mouse_state.hovered(),
104 cx,
105 )
106 .contained()
107 .with_style(style.header)
108 })
109 .with_cursor_style(CursorStyle::PointingHand)
110 .on_click(MouseButton::Left, move |_, this, cx| {
111 this.toggle(cx);
112 }),
113 );
114 if self.is_open {
115 result.add_child(Overlay::new(
116 UniformList::new(
117 self.list_state.clone(),
118 self.item_count,
119 cx,
120 move |this, mut range, items, cx| {
121 let selected_item_ix = this.selected_item_ix;
122 range.end = range.end.min(this.item_count);
123 items.extend(range.map(|ix| {
124 MouseEventHandler::new::<Item, _>(ix, cx, |mouse_state, cx| {
125 (this.render_item)(
126 ix,
127 if ix == selected_item_ix {
128 ItemType::Selected
129 } else {
130 ItemType::Unselected
131 },
132 mouse_state.hovered(),
133 cx,
134 )
135 })
136 .with_cursor_style(CursorStyle::PointingHand)
137 .on_click(MouseButton::Left, move |_, this, cx| {
138 this.set_selected_index(ix, cx);
139 })
140 .into_any()
141 }))
142 },
143 )
144 .constrained()
145 .with_max_height(200.)
146 .contained()
147 .with_style(style.menu),
148 ));
149 }
150 result.into_any()
151 }
152}