guise/input/
segmented.rs

1//! `SegmentedControl` — a stateful single-choice segmented switch (gpui entity).
2
3use gpui::prelude::*;
4use gpui::{div, px, App, Context, Entity, EventEmitter, IntoElement, SharedString, Window};
5
6use super::control_metrics;
7use crate::devtools::Probed;
8use crate::reactive::Signal;
9use crate::theme::{theme, ColorName, Size};
10
11/// Emitted when the selected segment changes. Carries the option index.
12#[derive(Debug, Clone)]
13pub struct SegmentedControlEvent(pub usize);
14
15/// A segmented control. Create with
16/// `cx.new(|cx| SegmentedControl::new(cx).data(["Day", "Week", "Month"]))`.
17pub struct SegmentedControl {
18  options: Vec<SharedString>,
19  selected: usize,
20  size: Size,
21}
22
23impl EventEmitter<SegmentedControlEvent> for SegmentedControl {}
24
25impl SegmentedControl {
26  pub fn new(_cx: &mut Context<Self>) -> Self {
27    SegmentedControl {
28      options: Vec::new(),
29      selected: 0,
30      size: Size::Sm,
31    }
32  }
33
34  pub fn data<I, S>(mut self, options: I) -> Self
35  where
36    I: IntoIterator<Item = S>,
37    S: Into<SharedString>,
38  {
39    self.options = options.into_iter().map(Into::into).collect();
40    self.selected = self.selected.min(self.options.len().saturating_sub(1));
41    self
42  }
43
44  pub fn selected(mut self, index: usize) -> Self {
45    self.selected = index;
46    self
47  }
48
49  pub fn size(mut self, size: Size) -> Self {
50    self.size = size;
51    self
52  }
53
54  pub fn selected_index(&self) -> usize {
55    self.selected
56  }
57
58  /// Two-way bind this control's selection to a `Signal<usize>`. The signal
59  /// is the source of truth: the control adopts its index now, clicks write
60  /// back through [`Signal::set_if_changed`], and signal writes move the
61  /// selection without emitting [`SegmentedControlEvent`]. Equality guards
62  /// on both directions prevent update loops.
63  pub fn bind(entity: &Entity<SegmentedControl>, signal: &Signal<usize>, cx: &mut App) {
64    let initial = signal.get(cx);
65    entity.update(cx, |this, cx| this.sync_selected(initial, cx));
66    let sink = signal.clone();
67    cx.subscribe(
68      entity,
69      move |_control, event: &SegmentedControlEvent, cx| {
70        sink.set_if_changed(cx, event.0);
71      },
72    )
73    .detach();
74    let control = entity.downgrade();
75    cx.observe(signal.entity(), move |observed, cx| {
76      let index = *observed.read(cx);
77      control
78        .update(cx, |this, cx| this.sync_selected(index, cx))
79        .ok();
80    })
81    .detach();
82  }
83
84  /// Programmatic set: repaint without emitting an event.
85  fn sync_selected(&mut self, index: usize, cx: &mut Context<Self>) {
86    let selected = index.min(self.options.len().saturating_sub(1));
87    if self.selected != selected {
88      self.selected = selected;
89      cx.notify();
90    }
91  }
92}
93
94impl Render for SegmentedControl {
95  fn render(&mut self, _window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
96    let t = theme(cx);
97    let (height, pad_x, font) = control_metrics(self.size);
98    let radius = t.radius(Size::Sm);
99    let track = t
100      .color(ColorName::Gray, if t.scheme.is_dark() { 8 } else { 1 })
101      .hsla();
102    let active_bg = t.surface().hsla();
103    let active_fg = t.text().hsla();
104    let inactive_fg = t.dimmed().hsla();
105
106    let count = self.options.len();
107    let selected = if count == 0 {
108      0
109    } else {
110      self.selected.min(count - 1)
111    };
112
113    let mut row = div()
114      .flex()
115      .items_center()
116      .gap(px(2.0))
117      .p(px(3.0))
118      .rounded(px(radius + 2.0))
119      .bg(track);
120
121    for (i, option) in self.options.iter().enumerate() {
122      let is_active = i == selected;
123      let mut seg = div()
124        .id(("guise-segment", i))
125        .flex()
126        .items_center()
127        .justify_center()
128        .h(px(height - 6.0))
129        .px(px(pad_x))
130        .rounded(px(radius))
131        .text_size(px(font))
132        .text_color(if is_active { active_fg } else { inactive_fg })
133        .child(option.clone())
134        .on_click(cx.listener(move |this, _ev, _window, cx| {
135          this.selected = i;
136          cx.emit(SegmentedControlEvent(i));
137          cx.notify();
138        }));
139      if is_active {
140        seg = seg.bg(active_bg).shadow_sm();
141      }
142      row = row.child(seg);
143    }
144    row.probe("SegmentedControl")
145  }
146}
guise/input/segmented.rs

guise/input/
segmented.rs
