zed: Add ability to restore last session w/ multiple windows (#14965)

This adds the ability for Zed to restore multiple windows after
restarting. It's now the default behavior.

Release Notes:

- Added ability to restore all windows that were open when Zed was quit.
Previously only the last used workspace was restored. This is now the
default behavior. To get back the old behavior, add the following to
your settings: `{"restore_on_startup": "last_workspace"}` (Part of
[#4985](https://github.com/zed-industries/zed/issues/4985) and
[#4683](https://github.com/zed-industries/zed/issues/4683))

Demo:



https://github.com/user-attachments/assets/57a375ec-0c6a-4724-97c4-3fea8f18bc2d

---------

Co-authored-by: Nathan <nathan@zed.dev>

crates/workspace/src/workspace.rs

@@ -58,6 +58,7 @@ pub use persistence::{
 use postage::stream::Stream;
 use project::{DirectoryLister, Project, ProjectEntryId, ProjectPath, Worktree, WorktreeId};
 use serde::Deserialize;
+use session::Session;
 use settings::Settings;
 use shared_screen::SharedScreen;
 use sqlez::{
@@ -536,6 +537,7 @@ pub struct AppState {
     pub fs: Arc<dyn fs::Fs>,
     pub build_window_options: fn(Option<Uuid>, &mut AppContext) -> WindowOptions,
     pub node_runtime: Arc<dyn NodeRuntime>,
+    pub session: Session,
 }
 
 struct GlobalAppState(Weak<AppState>);
@@ -569,6 +571,7 @@ impl AppState {
     #[cfg(any(test, feature = "test-support"))]
     pub fn test(cx: &mut AppContext) -> Arc<Self> {
         use node_runtime::FakeNodeRuntime;
+        use session::Session;
         use settings::SettingsStore;
         use ui::Context as _;
 
@@ -582,6 +585,7 @@ impl AppState {
         let clock = Arc::new(clock::FakeSystemClock::default());
         let http_client = http::FakeHttpClient::with_404_response();
         let client = Client::new(clock, http_client.clone(), cx);
+        let session = Session::test();
         let user_store = cx.new_model(|cx| UserStore::new(client.clone(), cx));
         let workspace_store = cx.new_model(|cx| WorkspaceStore::new(client.clone(), cx));
 
@@ -597,6 +601,7 @@ impl AppState {
             workspace_store,
             node_runtime: FakeNodeRuntime::new(),
             build_window_options: |_, _| Default::default(),
+            session,
         })
     }
 }
@@ -664,6 +669,7 @@ pub enum Event {
     ZoomChanged,
 }
 
+#[derive(Debug)]
 pub enum OpenVisible {
     All,
     None,
@@ -730,6 +736,7 @@ pub struct Workspace {
         Option<Box<dyn Fn(&mut Self, &mut ViewContext<Self>) -> AnyElement>>,
     serializable_items_tx: UnboundedSender<Box<dyn SerializableItemHandle>>,
     _items_serializer: Task<Result<()>>,
+    session_id: Option<String>,
 }
 
 impl EventEmitter<Event> for Workspace {}
@@ -908,6 +915,8 @@ impl Workspace {
 
         let modal_layer = cx.new_view(|_| ModalLayer::new());
 
+        let session_id = app_state.session.id().to_owned();
+
         let mut active_call = None;
         if let Some(call) = ActiveCall::try_global(cx) {
             let call = call.clone();
@@ -1023,6 +1032,7 @@ impl Workspace {
             render_disconnected_overlay: None,
             serializable_items_tx,
             _items_serializer,
+            session_id: Some(session_id),
         }
     }
 
@@ -1654,10 +1664,20 @@ impl Workspace {
                 }
             }
 
-            this.update(&mut cx, |this, cx| {
-                this.save_all_internal(SaveIntent::Close, cx)
-            })?
-            .await
+            let save_result = this
+                .update(&mut cx, |this, cx| {
+                    this.save_all_internal(SaveIntent::Close, cx)
+                })?
+                .await;
+
+            // If we're not quitting, but closing, we remove the workspace from
+            // the current session.
+            if !quitting && save_result.as_ref().map_or(false, |&res| res) {
+                this.update(&mut cx, |this, cx| this.remove_from_session(cx))?
+                    .await;
+            }
+
+            save_result
         })
     }
 
@@ -3838,6 +3858,11 @@ impl Workspace {
         }
     }
 
+    fn remove_from_session(&mut self, cx: &mut WindowContext) -> Task<()> {
+        self.session_id.take();
+        self.serialize_workspace_internal(cx)
+    }
+
     fn force_remove_pane(&mut self, pane: &View<Pane>, cx: &mut ViewContext<Workspace>) {
         self.panes.retain(|p| p != pane);
         self.panes
@@ -3992,7 +4017,6 @@ impl Workspace {
             None
         };
 
-        // don't save workspace state for the empty workspace.
         if let Some(location) = location {
             let center_group = build_serialized_pane_group(&self.center.root, cx);
             let docks = build_serialized_docks(self, cx);
@@ -4005,6 +4029,7 @@ impl Workspace {
                 display: Default::default(),
                 docks,
                 centered_layout: self.centered_layout,
+                session_id: self.session_id.clone(),
             };
             return cx.spawn(|_| persistence::DB.save_workspace(serialized_workspace));
         }
@@ -4258,6 +4283,7 @@ impl Workspace {
     #[cfg(any(test, feature = "test-support"))]
     pub fn test_new(project: Model<Project>, cx: &mut ViewContext<Self>) -> Self {
         use node_runtime::FakeNodeRuntime;
+        use session::Session;
 
         let client = project.read(cx).client();
         let user_store = project.read(cx).user_store();
@@ -4272,6 +4298,7 @@ impl Workspace {
             fs: project.read(cx).fs().clone(),
             build_window_options: |_, _| Default::default(),
             node_runtime: FakeNodeRuntime::new(),
+            session: Session::test(),
         });
         let workspace = Self::new(Default::default(), project, app_state, cx);
         workspace.active_pane.update(cx, |pane, cx| pane.focus(cx));
@@ -4873,6 +4900,11 @@ pub async fn last_opened_workspace_paths() -> Option<LocalPaths> {
     DB.last_workspace().await.log_err().flatten()
 }
 
+pub fn last_session_workspace_locations(last_session_id: &str) -> Option<Vec<LocalPaths>> {
+    DB.last_session_workspace_locations(last_session_id)
+        .log_err()
+}
+
 actions!(collab, [OpenChannelNotes]);
 actions!(zed, [OpenLog]);