1use gpui::{
  2    div, px, AnyView, Div, EventEmitter, FocusHandle, ParentElement, Render, StatelessInteractive,
  3    Styled, Subscription, View, ViewContext, VisualContext, WindowContext,
  4};
  5use ui::v_stack;
  6
  7pub struct ActiveModal {
  8    modal: AnyView,
  9    subscription: Subscription,
 10    previous_focus_handle: Option<FocusHandle>,
 11    focus_handle: FocusHandle,
 12}
 13
 14pub struct ModalLayer {
 15    active_modal: Option<ActiveModal>,
 16}
 17
 18pub trait Modal: Render + EventEmitter<ModalEvent> {
 19    fn focus(&self, cx: &mut WindowContext);
 20}
 21
 22pub enum ModalEvent {
 23    Dismissed,
 24}
 25
 26impl ModalLayer {
 27    pub fn new() -> Self {
 28        Self { active_modal: None }
 29    }
 30
 31    pub fn toggle_modal<V, B>(&mut self, cx: &mut ViewContext<Self>, build_view: B)
 32    where
 33        V: Modal,
 34        B: FnOnce(&mut ViewContext<V>) -> V,
 35    {
 36        let previous_focus = cx.focused();
 37
 38        if let Some(active_modal) = &self.active_modal {
 39            let is_close = active_modal.modal.clone().downcast::<V>().is_ok();
 40            self.hide_modal(cx);
 41            if is_close {
 42                return;
 43            }
 44        }
 45        let new_modal = cx.build_view(build_view);
 46        self.show_modal(new_modal, cx);
 47    }
 48
 49    pub fn show_modal<V>(&mut self, new_modal: View<V>, cx: &mut ViewContext<Self>)
 50    where
 51        V: Modal,
 52    {
 53        self.active_modal = Some(ActiveModal {
 54            modal: new_modal.clone().into(),
 55            subscription: cx.subscribe(&new_modal, |this, modal, e, cx| match e {
 56                ModalEvent::Dismissed => this.hide_modal(cx),
 57            }),
 58            previous_focus_handle: cx.focused(),
 59            focus_handle: cx.focus_handle(),
 60        });
 61        new_modal.update(cx, |modal, cx| modal.focus(cx));
 62        cx.notify();
 63    }
 64
 65    pub fn hide_modal(&mut self, cx: &mut ViewContext<Self>) {
 66        if let Some(active_modal) = self.active_modal.take() {
 67            if let Some(previous_focus) = active_modal.previous_focus_handle {
 68                if active_modal.focus_handle.contains_focused(cx) {
 69                    previous_focus.focus(cx);
 70                }
 71            }
 72        }
 73
 74        cx.notify();
 75    }
 76}
 77
 78impl Render for ModalLayer {
 79    type Element = Div<Self>;
 80
 81    fn render(&mut self, cx: &mut ViewContext<Self>) -> Self::Element {
 82        let Some(active_modal) = &self.active_modal else {
 83            return div();
 84        };
 85
 86        div()
 87            .absolute()
 88            .flex()
 89            .flex_col()
 90            .items_center()
 91            .size_full()
 92            .top_0()
 93            .left_0()
 94            .z_index(400)
 95            .child(
 96                v_stack()
 97                    .h(px(0.0))
 98                    .top_20()
 99                    .track_focus(&active_modal.focus_handle)
100                    .on_mouse_down_out(|this: &mut Self, event, cx| {
101                        this.hide_modal(cx);
102                    })
103                    .child(active_modal.modal.clone()),
104            )
105    }
106}