Allow modals to override their dismissal (#3565)

Release Notes:

- N/A

crates/workspace2/src/modal_layer.rs

@@ -1,11 +1,32 @@
 use gpui::{
-    div, prelude::*, px, AnyView, Div, FocusHandle, ManagedView, Render, Subscription, View,
-    ViewContext,
+    div, prelude::*, px, AnyView, Div, FocusHandle, ManagedView, Render, Subscription, Task, View,
+    ViewContext, WindowContext,
 };
 use ui::{h_stack, v_stack};
 
+pub trait ModalView: ManagedView {
+    fn dismiss(&mut self, cx: &mut ViewContext<Self>) -> Task<bool> {
+        Task::ready(true)
+    }
+}
+
+trait ModalViewHandle {
+    fn should_dismiss(&mut self, cx: &mut WindowContext) -> Task<bool>;
+    fn view(&self) -> AnyView;
+}
+
+impl<V: ModalView> ModalViewHandle for View<V> {
+    fn should_dismiss(&mut self, cx: &mut WindowContext) -> Task<bool> {
+        self.update(cx, |this, cx| this.dismiss(cx))
+    }
+
+    fn view(&self) -> AnyView {
+        self.clone().into()
+    }
+}
+
 pub struct ActiveModal {
-    modal: AnyView,
+    modal: Box<dyn ModalViewHandle>,
     subscription: Subscription,
     previous_focus_handle: Option<FocusHandle>,
     focus_handle: FocusHandle,
@@ -22,11 +43,11 @@ impl ModalLayer {
 
     pub fn toggle_modal<V, B>(&mut self, cx: &mut ViewContext<Self>, build_view: B)
     where
-        V: ManagedView,
+        V: ModalView,
         B: FnOnce(&mut ViewContext<V>) -> V,
     {
         if let Some(active_modal) = &self.active_modal {
-            let is_close = active_modal.modal.clone().downcast::<V>().is_ok();
+            let is_close = active_modal.modal.view().downcast::<V>().is_ok();
             self.hide_modal(cx);
             if is_close {
                 return;
@@ -38,10 +59,10 @@ impl ModalLayer {
 
     pub fn show_modal<V>(&mut self, new_modal: View<V>, cx: &mut ViewContext<Self>)
     where
-        V: ManagedView,
+        V: ModalView,
     {
         self.active_modal = Some(ActiveModal {
-            modal: new_modal.clone().into(),
+            modal: Box::new(new_modal.clone()),
             subscription: cx.subscribe(&new_modal, |this, modal, e, cx| this.hide_modal(cx)),
             previous_focus_handle: cx.focused(),
             focus_handle: cx.focus_handle(),
@@ -51,15 +72,28 @@ impl ModalLayer {
     }
 
     pub fn hide_modal(&mut self, cx: &mut ViewContext<Self>) {
-        if let Some(active_modal) = self.active_modal.take() {
-            if let Some(previous_focus) = active_modal.previous_focus_handle {
-                if active_modal.focus_handle.contains_focused(cx) {
-                    previous_focus.focus(cx);
-                }
-            }
-        }
+        let Some(active_modal) = self.active_modal.as_mut() else {
+            return;
+        };
 
-        cx.notify();
+        let dismiss = active_modal.modal.should_dismiss(cx);
+
+        cx.spawn(|this, mut cx| async move {
+            if dismiss.await {
+                this.update(&mut cx, |this, cx| {
+                    if let Some(active_modal) = this.active_modal.take() {
+                        if let Some(previous_focus) = active_modal.previous_focus_handle {
+                            if active_modal.focus_handle.contains_focused(cx) {
+                                previous_focus.focus(cx);
+                            }
+                        }
+                        cx.notify();
+                    }
+                })
+                .ok();
+            }
+        })
+        .detach();
     }
 
     pub fn active_modal<V>(&self) -> Option<View<V>>
@@ -67,7 +101,7 @@ impl ModalLayer {
         V: 'static,
     {
         let active_modal = self.active_modal.as_ref()?;
-        active_modal.modal.clone().downcast::<V>().ok()
+        active_modal.modal.view().downcast::<V>().ok()
     }
 }
 
@@ -98,7 +132,7 @@ impl Render for ModalLayer {
                             .on_mouse_down_out(cx.listener(|this, _, cx| {
                                 this.hide_modal(cx);
                             }))
-                            .child(active_modal.modal.clone()),
+                            .child(active_modal.modal.view()),
                     ),
             )
     }

crates/workspace2/src/workspace2.rs

@@ -3414,7 +3414,7 @@ impl Workspace {
         self.modal_layer.read(cx).active_modal()
     }
 
-    pub fn toggle_modal<V: ManagedView, B>(&mut self, cx: &mut ViewContext<Self>, build: B)
+    pub fn toggle_modal<V: ModalView, B>(&mut self, cx: &mut ViewContext<Self>, build: B)
     where
         B: FnOnce(&mut ViewContext<V>) -> V,
     {