1use gpui::{
2 AnyView, DismissEvent, Entity, EventEmitter, FocusHandle, Focusable as _, ManagedView,
3 MouseButton, Subscription,
4};
5use ui::prelude::*;
6
7#[derive(Debug)]
8pub enum DismissDecision {
9 Dismiss(bool),
10 Pending,
11}
12
13pub trait ModalView: ManagedView {
14 fn on_before_dismiss(
15 &mut self,
16 _window: &mut Window,
17 _: &mut Context<Self>,
18 ) -> DismissDecision {
19 DismissDecision::Dismiss(true)
20 }
21
22 fn fade_out_background(&self) -> bool {
23 false
24 }
25
26 fn render_bare(&self) -> bool {
27 false
28 }
29}
30
31trait ModalViewHandle {
32 fn on_before_dismiss(&mut self, window: &mut Window, cx: &mut App) -> DismissDecision;
33 fn view(&self) -> AnyView;
34 fn fade_out_background(&self, cx: &mut App) -> bool;
35 fn render_bare(&self, cx: &mut App) -> bool;
36}
37
38impl<V: ModalView> ModalViewHandle for Entity<V> {
39 fn on_before_dismiss(&mut self, window: &mut Window, cx: &mut App) -> DismissDecision {
40 self.update(cx, |this, cx| this.on_before_dismiss(window, cx))
41 }
42
43 fn view(&self) -> AnyView {
44 self.clone().into()
45 }
46
47 fn fade_out_background(&self, cx: &mut App) -> bool {
48 self.read(cx).fade_out_background()
49 }
50
51 fn render_bare(&self, cx: &mut App) -> bool {
52 self.read(cx).render_bare()
53 }
54}
55
56pub struct ActiveModal {
57 modal: Box<dyn ModalViewHandle>,
58 _subscriptions: [Subscription; 2],
59 previous_focus_handle: Option<FocusHandle>,
60 focus_handle: FocusHandle,
61}
62
63pub struct ModalLayer {
64 active_modal: Option<ActiveModal>,
65 dismiss_on_focus_lost: bool,
66}
67
68pub(crate) struct ModalOpenedEvent;
69
70impl EventEmitter<ModalOpenedEvent> for ModalLayer {}
71
72impl Default for ModalLayer {
73 fn default() -> Self {
74 Self::new()
75 }
76}
77
78impl ModalLayer {
79 pub fn new() -> Self {
80 Self {
81 active_modal: None,
82 dismiss_on_focus_lost: false,
83 }
84 }
85
86 /// Toggles a modal of type `V`. If a modal of the same type is currently active,
87 /// it will be hidden. If a different modal is active, it will be replaced with the new one.
88 /// If no modal is active, the new modal will be shown.
89 ///
90 /// If closing the current modal fails (e.g., due to `on_before_dismiss` returning
91 /// `DismissDecision::Dismiss(false)` or `DismissDecision::Pending`), the new modal
92 /// will not be shown.
93 pub fn toggle_modal<V, B>(&mut self, window: &mut Window, cx: &mut Context<Self>, build_view: B)
94 where
95 V: ModalView,
96 B: FnOnce(&mut Window, &mut Context<V>) -> V,
97 {
98 if let Some(active_modal) = &self.active_modal {
99 let should_close = active_modal.modal.view().downcast::<V>().is_ok();
100 let did_close = self.hide_modal(window, cx);
101 if should_close || !did_close {
102 return;
103 }
104 }
105 let new_modal = cx.new(|cx| build_view(window, cx));
106 self.show_modal(new_modal, window, cx);
107 cx.emit(ModalOpenedEvent);
108 }
109
110 /// Shows a modal and sets up subscriptions for dismiss events and focus tracking.
111 /// The modal is automatically focused after being shown.
112 fn show_modal<V>(&mut self, new_modal: Entity<V>, window: &mut Window, cx: &mut Context<Self>)
113 where
114 V: ModalView,
115 {
116 let focus_handle = cx.focus_handle();
117 self.active_modal = Some(ActiveModal {
118 modal: Box::new(new_modal.clone()),
119 _subscriptions: [
120 cx.subscribe_in(
121 &new_modal,
122 window,
123 |this, _, _: &DismissEvent, window, cx| {
124 this.hide_modal(window, cx);
125 },
126 ),
127 cx.on_focus_out(&focus_handle, window, |this, _event, window, cx| {
128 if this.dismiss_on_focus_lost {
129 this.hide_modal(window, cx);
130 }
131 }),
132 ],
133 previous_focus_handle: window.focused(cx),
134 focus_handle,
135 });
136 cx.defer_in(window, move |_, window, cx| {
137 window.focus(&new_modal.focus_handle(cx), cx);
138 });
139 cx.notify();
140 }
141
142 /// Attempts to hide the currently active modal.
143 ///
144 /// The modal's `on_before_dismiss` method is called to determine if dismissal should proceed.
145 /// If dismissal is allowed, the modal is removed and focus is restored to the previously
146 /// focused element.
147 ///
148 /// Returns `true` if the modal was successfully hidden, `false` otherwise.
149 pub fn hide_modal(&mut self, window: &mut Window, cx: &mut Context<Self>) -> bool {
150 let Some(active_modal) = self.active_modal.as_mut() else {
151 self.dismiss_on_focus_lost = false;
152 return false;
153 };
154
155 match active_modal.modal.on_before_dismiss(window, cx) {
156 DismissDecision::Dismiss(should_dismiss) => {
157 if !should_dismiss {
158 self.dismiss_on_focus_lost = !should_dismiss;
159 return false;
160 }
161 }
162 DismissDecision::Pending => {
163 self.dismiss_on_focus_lost = false;
164 return false;
165 }
166 }
167
168 if let Some(active_modal) = self.active_modal.take() {
169 if let Some(previous_focus) = active_modal.previous_focus_handle
170 && active_modal.focus_handle.contains_focused(window, cx)
171 {
172 previous_focus.focus(window, cx);
173 }
174 cx.notify();
175 }
176 self.dismiss_on_focus_lost = false;
177 true
178 }
179
180 /// Returns the currently active modal if it is of type `V`.
181 pub fn active_modal<V>(&self) -> Option<Entity<V>>
182 where
183 V: 'static,
184 {
185 let active_modal = self.active_modal.as_ref()?;
186 active_modal.modal.view().downcast::<V>().ok()
187 }
188
189 pub fn has_active_modal(&self) -> bool {
190 self.active_modal.is_some()
191 }
192}
193
194impl Render for ModalLayer {
195 fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
196 let Some(active_modal) = &self.active_modal else {
197 return div().into_any_element();
198 };
199
200 if active_modal.modal.render_bare(cx) {
201 return active_modal.modal.view().into_any_element();
202 }
203
204 div()
205 .absolute()
206 .size_full()
207 .inset_0()
208 .occlude()
209 .when(active_modal.modal.fade_out_background(cx), |this| {
210 let mut background = cx.theme().colors().elevated_surface_background;
211 background.fade_out(0.2);
212 this.bg(background)
213 })
214 .on_mouse_down(
215 MouseButton::Left,
216 cx.listener(|this, _, window, cx| {
217 this.hide_modal(window, cx);
218 }),
219 )
220 .child(
221 v_flex()
222 .h(px(0.0))
223 .top_20()
224 .items_center()
225 .track_focus(&active_modal.focus_handle)
226 .child(
227 h_flex()
228 .occlude()
229 .child(active_modal.modal.view())
230 .on_mouse_down(MouseButton::Left, |_, _, cx| {
231 cx.stop_propagation();
232 }),
233 ),
234 )
235 .into_any_element()
236 }
237}