1use futures::FutureExt;
  2use gpui::{
  3    div, prelude::*, px, AnyView, Div, FocusHandle, ManagedView, Render, Subscription, Task, View,
  4    ViewContext, WindowContext,
  5};
  6use ui::{h_stack, v_stack};
  7
  8pub trait ModalView: ManagedView {
  9    fn dismiss(&mut self, cx: &mut ViewContext<Self>) -> Task<bool> {
 10        Task::ready(true)
 11    }
 12}
 13
 14trait ModalViewHandle {
 15    fn should_dismiss(&mut self, cx: &mut WindowContext) -> Task<bool>;
 16    fn view(&self) -> AnyView;
 17}
 18
 19impl<V: ModalView> ModalViewHandle for View<V> {
 20    fn should_dismiss(&mut self, cx: &mut WindowContext) -> Task<bool> {
 21        self.update(cx, |this, cx| this.dismiss(cx))
 22    }
 23
 24    fn view(&self) -> AnyView {
 25        self.clone().into()
 26    }
 27}
 28
 29pub struct ActiveModal {
 30    modal: Box<dyn ModalViewHandle>,
 31    subscription: Subscription,
 32    previous_focus_handle: Option<FocusHandle>,
 33    focus_handle: FocusHandle,
 34}
 35
 36pub struct ModalLayer {
 37    active_modal: Option<ActiveModal>,
 38}
 39
 40impl ModalLayer {
 41    pub fn new() -> Self {
 42        Self { active_modal: None }
 43    }
 44
 45    pub fn toggle_modal<V, B>(&mut self, cx: &mut ViewContext<Self>, build_view: B)
 46    where
 47        V: ModalView,
 48        B: FnOnce(&mut ViewContext<V>) -> V,
 49    {
 50        if let Some(active_modal) = &self.active_modal {
 51            let is_close = active_modal.modal.view().downcast::<V>().is_ok();
 52            self.hide_modal(cx);
 53            if is_close {
 54                return;
 55            }
 56        }
 57        let new_modal = cx.build_view(build_view);
 58        self.show_modal(new_modal, cx);
 59    }
 60
 61    pub fn show_modal<V>(&mut self, new_modal: View<V>, cx: &mut ViewContext<Self>)
 62    where
 63        V: ModalView,
 64    {
 65        self.active_modal = Some(ActiveModal {
 66            modal: Box::new(new_modal.clone()),
 67            subscription: cx.subscribe(&new_modal, |this, modal, e, cx| this.hide_modal(cx)),
 68            previous_focus_handle: cx.focused(),
 69            focus_handle: cx.focus_handle(),
 70        });
 71        cx.focus_view(&new_modal);
 72        cx.notify();
 73    }
 74
 75    pub fn hide_modal(&mut self, cx: &mut ViewContext<Self>) {
 76        let Some(active_modal) = self.active_modal.as_mut() else {
 77            return;
 78        };
 79
 80        let dismiss = active_modal.modal.should_dismiss(cx);
 81
 82        cx.spawn(|this, mut cx| async move {
 83            if dismiss.await {
 84                this.update(&mut cx, |this, cx| {
 85                    if let Some(active_modal) = this.active_modal.take() {
 86                        if let Some(previous_focus) = active_modal.previous_focus_handle {
 87                            if active_modal.focus_handle.contains_focused(cx) {
 88                                previous_focus.focus(cx);
 89                            }
 90                        }
 91                        cx.notify();
 92                    }
 93                })
 94                .ok();
 95            }
 96        })
 97        .shared()
 98        .detach();
 99    }
100
101    pub fn active_modal<V>(&self) -> Option<View<V>>
102    where
103        V: 'static,
104    {
105        let active_modal = self.active_modal.as_ref()?;
106        active_modal.modal.view().downcast::<V>().ok()
107    }
108}
109
110impl Render for ModalLayer {
111    type Element = Div;
112
113    fn render(&mut self, cx: &mut ViewContext<Self>) -> Self::Element {
114        let Some(active_modal) = &self.active_modal else {
115            return div();
116        };
117
118        div()
119            .absolute()
120            .size_full()
121            .top_0()
122            .left_0()
123            .z_index(400)
124            .child(
125                v_stack()
126                    .h(px(0.0))
127                    .top_20()
128                    .flex()
129                    .flex_col()
130                    .items_center()
131                    .track_focus(&active_modal.focus_handle)
132                    .child(
133                        h_stack()
134                            .on_mouse_down_out(cx.listener(|this, _, cx| {
135                                this.hide_modal(cx);
136                            }))
137                            .child(active_modal.modal.view()),
138                    ),
139            )
140    }
141}