Replace disconnected channel notes views when re-opening the notes

crates/channel/src/channel_buffer.rs

@@ -99,6 +99,10 @@ impl ChannelBuffer {
         }))
     }
 
+    pub fn remote_id(&self, cx: &AppContext) -> u64 {
+        self.buffer.read(cx).remote_id()
+    }
+
     pub fn user_store(&self) -> &ModelHandle<UserStore> {
         &self.user_store
     }

crates/collab_ui/src/channel_view.rs

@@ -24,7 +24,7 @@ use workspace::{
     item::{FollowableItem, Item, ItemHandle},
     register_followable_item,
     searchable::SearchableItemHandle,
-    ItemNavHistory, Pane, ViewId, Workspace, WorkspaceId,
+    ItemNavHistory, Pane, SaveIntent, ViewId, Workspace, WorkspaceId,
 };
 
 actions!(channel_view, [Deploy]);
@@ -93,15 +93,36 @@ impl ChannelView {
             }
 
             pane.update(&mut cx, |pane, cx| {
-                pane.items_of_type::<Self>()
+                let buffer_id = channel_buffer.read(cx).remote_id(cx);
-                    .find(|channel_view| channel_view.read(cx).channel_buffer == channel_buffer)
+
-                    .unwrap_or_else(|| {
+                let existing_view = pane
-                        cx.add_view(|cx| {
+                    .items_of_type::<Self>()
-                            let mut this = Self::new(project, channel_store, channel_buffer, cx);
+                    .find(|view| view.read(cx).channel_buffer.read(cx).remote_id(cx) == buffer_id);
-                            this.acknowledge_buffer_version(cx);
+
-                            this
+                // If this channel buffer is already open in this pane, just return it.
-                        })
+                if let Some(existing_view) = existing_view.clone() {
-                    })
+                    if existing_view.read(cx).channel_buffer == channel_buffer {
+                        return existing_view;
+                    }
+                }
+
+                let view = cx.add_view(|cx| {
+                    let mut this = Self::new(project, channel_store, channel_buffer, cx);
+                    this.acknowledge_buffer_version(cx);
+                    this
+                });
+
+                // If the pane contained a disconnected view for this channel buffer,
+                // replace that.
+                if let Some(existing_item) = existing_view {
+                    if let Some(ix) = pane.index_for_item(&existing_item) {
+                        pane.close_item_by_id(existing_item.id(), SaveIntent::Skip, cx)
+                            .detach();
+                        pane.add_item(Box::new(view.clone()), true, true, Some(ix), cx);
+                    }
+                }
+
+                view
             })
             .ok_or_else(|| anyhow!("pane was dropped"))
         })