1use crate::{
2 action, elements::*, AppContext, Entity, MutableAppContext, RenderContext, View, ViewContext,
3 WeakViewHandle,
4};
5
6pub struct Select {
7 handle: WeakViewHandle<Self>,
8 render_item: Box<dyn Fn(usize, ItemType, bool, &AppContext) -> ElementBox>,
9 selected_item_ix: usize,
10 item_count: usize,
11 is_open: bool,
12 list_state: UniformListState,
13 build_style: Option<Box<dyn FnMut(&mut MutableAppContext) -> SelectStyle>>,
14}
15
16#[derive(Clone, Default)]
17pub struct SelectStyle {
18 pub header: ContainerStyle,
19 pub menu: ContainerStyle,
20}
21
22pub enum ItemType {
23 Header,
24 Selected,
25 Unselected,
26}
27
28action!(ToggleSelect);
29action!(SelectItem, usize);
30
31pub enum Event {}
32
33pub fn init(cx: &mut MutableAppContext) {
34 cx.add_action(Select::toggle);
35 cx.add_action(Select::select_item);
36}
37
38impl Select {
39 pub fn new<F: 'static + Fn(usize, ItemType, bool, &AppContext) -> ElementBox>(
40 item_count: usize,
41 cx: &mut ViewContext<Self>,
42 render_item: F,
43 ) -> Self {
44 Self {
45 handle: cx.handle().downgrade(),
46 render_item: Box::new(render_item),
47 selected_item_ix: 0,
48 item_count,
49 is_open: false,
50 list_state: UniformListState::default(),
51 build_style: Default::default(),
52 }
53 }
54
55 pub fn with_style(
56 mut self,
57 f: impl 'static + FnMut(&mut MutableAppContext) -> SelectStyle,
58 ) -> Self {
59 self.build_style = Some(Box::new(f));
60 self
61 }
62
63 pub fn set_item_count(&mut self, count: usize, cx: &mut ViewContext<Self>) {
64 self.item_count = count;
65 cx.notify();
66 }
67
68 fn toggle(&mut self, _: &ToggleSelect, cx: &mut ViewContext<Self>) {
69 self.is_open = !self.is_open;
70 cx.notify();
71 }
72
73 fn select_item(&mut self, action: &SelectItem, cx: &mut ViewContext<Self>) {
74 self.selected_item_ix = action.0;
75 self.is_open = false;
76 cx.notify();
77 }
78}
79
80impl Entity for Select {
81 type Event = Event;
82}
83
84impl View for Select {
85 fn ui_name() -> &'static str {
86 "Select"
87 }
88
89 fn render(&mut self, cx: &mut RenderContext<Self>) -> ElementBox {
90 if self.item_count == 0 {
91 return Empty::new().boxed();
92 }
93
94 enum Header {}
95 enum Item {}
96
97 let style = if let Some(build_style) = self.build_style.as_mut() {
98 (build_style)(cx)
99 } else {
100 Default::default()
101 };
102 let mut result = Flex::column().with_child(
103 MouseEventHandler::new::<Header, _, _, _>(self.handle.id(), cx, |mouse_state, cx| {
104 Container::new((self.render_item)(
105 self.selected_item_ix,
106 ItemType::Header,
107 mouse_state.hovered,
108 cx,
109 ))
110 .with_style(&style.header)
111 .boxed()
112 })
113 .on_click(move |cx| cx.dispatch_action(ToggleSelect))
114 .boxed(),
115 );
116 if self.is_open {
117 let handle = self.handle.clone();
118 result.add_child(
119 Overlay::new(
120 Container::new(
121 ConstrainedBox::new(
122 UniformList::new(
123 self.list_state.clone(),
124 self.item_count,
125 move |mut range, items, mut cx| {
126 let handle = handle.upgrade(cx).unwrap();
127 let this = handle.read(cx);
128 let selected_item_ix = this.selected_item_ix;
129 range.end = range.end.min(this.item_count);
130 items.extend(range.map(|ix| {
131 MouseEventHandler::new::<Item, _, _, _>(
132 (handle.id(), ix),
133 &mut cx,
134 |mouse_state, cx| {
135 (handle.read(*cx).render_item)(
136 ix,
137 if ix == selected_item_ix {
138 ItemType::Selected
139 } else {
140 ItemType::Unselected
141 },
142 mouse_state.hovered,
143 cx,
144 )
145 },
146 )
147 .on_click(move |cx| cx.dispatch_action(SelectItem(ix)))
148 .boxed()
149 }))
150 },
151 )
152 .boxed(),
153 )
154 .with_max_height(200.)
155 .boxed(),
156 )
157 .with_style(&style.menu)
158 .boxed(),
159 )
160 .boxed(),
161 )
162 }
163 result.boxed()
164 }
165}