Allow subscription/notification to be cancelled by dropping the returned Subscription

Co-Authored-By: Nathan Sobo <nathan@zed.dev>

zed/src/editor.rs

@@ -324,9 +324,10 @@ impl Editor {
     ) -> Self {
         let display_map =
             cx.add_model(|cx| DisplayMap::new(buffer.clone(), settings.borrow().clone(), None, cx));
-        cx.observe(&buffer, Self::on_buffer_changed);
-        cx.subscribe(&buffer, Self::on_buffer_event);
-        cx.observe(&display_map, Self::on_display_map_changed);
+        cx.observe(&buffer, Self::on_buffer_changed).detach();
+        cx.subscribe(&buffer, Self::on_buffer_event).detach();
+        cx.observe(&display_map, Self::on_display_map_changed)
+            .detach();
 
         let mut next_selection_id = 0;
         let selection_set_id = buffer.update(cx, |buffer, cx| {

zed/src/editor/buffer.rs

@@ -2943,11 +2943,13 @@ mod tests {
             let buffer_1_events = buffer_1_events.clone();
             cx.subscribe(&buffer1, move |_, _, event, _| {
                 buffer_1_events.borrow_mut().push(event.clone())
-            });
+            })
+            .detach();
             let buffer_2_events = buffer_2_events.clone();
             cx.subscribe(&buffer2, move |_, _, event, _| {
                 buffer_2_events.borrow_mut().push(event.clone())
-            });
+            })
+            .detach();
 
             // An edit emits an edited event, followed by a dirtied event,
             // since the buffer was previously in a clean state.
@@ -3382,7 +3384,8 @@ mod tests {
             cx.subscribe(&buffer1, {
                 let events = events.clone();
                 move |_, _, event, _| events.borrow_mut().push(event.clone())
-            });
+            })
+            .detach();
 
             assert!(!buffer.is_dirty());
             assert!(events.borrow().is_empty());
@@ -3438,7 +3441,8 @@ mod tests {
             cx.subscribe(&buffer2, {
                 let events = events.clone();
                 move |_, _, event, _| events.borrow_mut().push(event.clone())
-            });
+            })
+            .detach();
         });
 
         fs::remove_file(dir.path().join("file2")).unwrap();
@@ -3458,7 +3462,8 @@ mod tests {
             cx.subscribe(&buffer3, {
                 let events = events.clone();
                 move |_, _, event, _| events.borrow_mut().push(event.clone())
-            });
+            })
+            .detach();
         });
 
         tree.flush_fs_events(&cx).await;

zed/src/editor/display_map.rs

@@ -32,7 +32,7 @@ impl DisplayMap {
         let (fold_map, snapshot) = FoldMap::new(buffer.clone(), cx);
         let (tab_map, snapshot) = TabMap::new(snapshot, settings.tab_size);
         let wrap_map = cx.add_model(|cx| WrapMap::new(snapshot, settings, wrap_width, cx));
-        cx.observe(&wrap_map, |_, _, cx| cx.notify());
+        cx.observe(&wrap_map, |_, _, cx| cx.notify()).detach();
         DisplayMap {
             buffer,
             fold_map,

zed/src/file_finder.rs

@@ -252,7 +252,7 @@ impl FileFinder {
         workspace.toggle_modal(cx, |cx, workspace| {
             let handle = cx.handle();
             let finder = cx.add_view(|cx| Self::new(workspace.settings.clone(), handle, cx));
-            cx.subscribe(&finder, Self::on_event);
+            cx.subscribe(&finder, Self::on_event).detach();
             finder
         });
     }
@@ -281,10 +281,11 @@ impl FileFinder {
         workspace: ViewHandle<Workspace>,
         cx: &mut ViewContext<Self>,
     ) -> Self {
-        cx.observe(&workspace, Self::workspace_updated);
+        cx.observe(&workspace, Self::workspace_updated).detach();
 
         let query_buffer = cx.add_view(|cx| Editor::single_line(settings.clone(), cx));
-        cx.subscribe(&query_buffer, Self::on_query_editor_event);
+        cx.subscribe(&query_buffer, Self::on_query_editor_event)
+            .detach();
 
         Self {
             handle: cx.handle().downgrade(),

zed/src/test.rs

@@ -190,7 +190,8 @@ impl<T: Entity> Observer<T> {
         let observer = cx.add_model(|cx| {
             cx.observe(handle, move |_, _, _| {
                 let _ = notify_tx.try_send(());
-            });
+            })
+            .detach();
             Observer(PhantomData)
         });
         (observer, notify_rx)

zed/src/theme_selector.rs

@@ -61,7 +61,8 @@ impl ThemeSelector {
         cx: &mut ViewContext<Self>,
     ) -> Self {
         let query_buffer = cx.add_view(|cx| Editor::single_line(settings.clone(), cx));
-        cx.subscribe(&query_buffer, Self::on_query_editor_event);
+        cx.subscribe(&query_buffer, Self::on_query_editor_event)
+            .detach();
 
         let mut this = Self {
             settings,
@@ -86,7 +87,7 @@ impl ThemeSelector {
                     cx,
                 )
             });
-            cx.subscribe(&selector, Self::on_event);
+            cx.subscribe(&selector, Self::on_event).detach();
             selector
         });
     }

zed/src/workspace.rs

@@ -290,7 +290,8 @@ impl<T: ItemView> ItemViewHandle for ViewHandle<T> {
                     cx.notify()
                 }
             })
-        })
+            .detach();
+        });
     }
 
     fn save(&self, cx: &mut MutableAppContext) -> Result<Task<Result<()>>> {
@@ -360,7 +361,8 @@ impl Workspace {
         let pane_id = pane.id();
         cx.subscribe(&pane, move |me, _, event, cx| {
             me.handle_pane_event(pane_id, event, cx)
-        });
+        })
+        .detach();
         cx.focus(&pane);
 
         let mut left_sidebar = Sidebar::new(Side::Left);
@@ -526,7 +528,7 @@ impl Workspace {
         cx.spawn(|this, mut cx| async move {
             let worktree = Worktree::open_local(path, languages, fs, &mut cx).await?;
             this.update(&mut cx, |this, cx| {
-                cx.observe(&worktree, |_, _, cx| cx.notify());
+                cx.observe(&worktree, |_, _, cx| cx.notify()).detach();
                 this.worktrees.insert(worktree.clone());
                 cx.notify();
             });
@@ -835,7 +837,7 @@ impl Workspace {
                 Worktree::open_remote(rpc.clone(), worktree_id, access_token, languages, &mut cx)
                     .await?;
             this.update(&mut cx, |workspace, cx| {
-                cx.observe(&worktree, |_, _, cx| cx.notify());
+                cx.observe(&worktree, |_, _, cx| cx.notify()).detach();
                 workspace.worktrees.insert(worktree);
                 cx.notify();
             });
@@ -856,7 +858,8 @@ impl Workspace {
         let pane_id = pane.id();
         cx.subscribe(&pane, move |me, _, event, cx| {
             me.handle_pane_event(pane_id, event, cx)
-        });
+        })
+        .detach();
         self.panes.push(pane.clone());
         self.activate_pane(pane.clone(), cx);
         pane