Persist selections for editors (#25083)

Part of https://github.com/zed-industries/zed/issues/7371
Closes https://github.com/zed-industries/zed/issues/12853

Release Notes:

- Started to persist latest selections for editors, to restore those on
restart

crates/editor/src/editor.rs

@@ -106,6 +106,7 @@ use language::{
 use language::{point_to_lsp, BufferRow, CharClassifier, Runnable, RunnableRange};
 use linked_editing_ranges::refresh_linked_ranges;
 use mouse_context_menu::MouseContextMenu;
+use persistence::DB;
 pub use proposed_changes_editor::{
     ProposedChangeLocation, ProposedChangesEditor, ProposedChangesEditorToolbar,
 };
@@ -171,8 +172,14 @@ use ui::{
     Tooltip,
 };
 use util::{defer, maybe, post_inc, RangeExt, ResultExt, TryFutureExt};
-use workspace::item::{ItemHandle, PreviewTabsSettings};
-use workspace::notifications::{DetachAndPromptErr, NotificationId, NotifyTaskExt};
+use workspace::{
+    item::{ItemHandle, PreviewTabsSettings},
+    ItemId, RestoreOnStartupBehavior,
+};
+use workspace::{
+    notifications::{DetachAndPromptErr, NotificationId, NotifyTaskExt},
+    WorkspaceSettings,
+};
 use workspace::{
     searchable::SearchEvent, ItemNavHistory, SplitDirection, ViewId, Workspace, WorkspaceId,
 };
@@ -763,6 +770,7 @@ pub struct Editor {
     selection_mark_mode: bool,
     toggle_fold_multiple_buffers: Task<()>,
     _scroll_cursor_center_top_bottom_task: Task<()>,
+    serialize_selections: Task<()>,
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Default)]
@@ -1475,6 +1483,7 @@ impl Editor {
             _scroll_cursor_center_top_bottom_task: Task::ready(()),
             selection_mark_mode: false,
             toggle_fold_multiple_buffers: Task::ready(()),
+            serialize_selections: Task::ready(()),
             text_style_refinement: None,
             load_diff_task: load_uncommitted_diff,
         };
@@ -2181,9 +2190,37 @@ impl Editor {
         self.blink_manager.update(cx, BlinkManager::pause_blinking);
         cx.emit(EditorEvent::SelectionsChanged { local });
 
-        if self.selections.disjoint_anchors().len() == 1 {
+        let selections = &self.selections.disjoint;
+        if selections.len() == 1 {
             cx.emit(SearchEvent::ActiveMatchChanged)
         }
+        if local
+            && WorkspaceSettings::get(None, cx).restore_on_startup != RestoreOnStartupBehavior::None
+        {
+            if let Some(workspace_id) = self.workspace.as_ref().and_then(|workspace| workspace.1) {
+                let background_executor = cx.background_executor().clone();
+                let editor_id = cx.entity().entity_id().as_u64() as ItemId;
+                let snapshot = self.buffer().read(cx).snapshot(cx);
+                let selections = selections.clone();
+                self.serialize_selections = cx.background_spawn(async move {
+                    background_executor.timer(Duration::from_millis(100)).await;
+                    let selections = selections
+                        .iter()
+                        .map(|selection| {
+                            (
+                                selection.start.to_offset(&snapshot),
+                                selection.end.to_offset(&snapshot),
+                            )
+                        })
+                        .collect();
+                    DB.save_editor_selections(editor_id, workspace_id, selections)
+                        .await
+                        .context("persisting editor selections")
+                        .log_err();
+                });
+            }
+        }
+
         cx.notify();
     }
 
@@ -2197,7 +2234,7 @@ impl Editor {
         self.change_selections_inner(autoscroll, true, window, cx, change)
     }
 
-    pub fn change_selections_inner<R>(
+    fn change_selections_inner<R>(
         &mut self,
         autoscroll: Option<Autoscroll>,
         request_completions: bool,
@@ -14982,6 +15019,31 @@ impl Editor {
     pub fn wait_for_diff_to_load(&self) -> Option<Shared<Task<()>>> {
         self.load_diff_task.clone()
     }
+
+    fn read_selections_from_db(
+        &mut self,
+        item_id: u64,
+        workspace_id: WorkspaceId,
+        window: &mut Window,
+        cx: &mut Context<Editor>,
+    ) {
+        if WorkspaceSettings::get(None, cx).restore_on_startup == RestoreOnStartupBehavior::None {
+            return;
+        }
+        let Some(selections) = DB.get_editor_selections(item_id, workspace_id).log_err() else {
+            return;
+        };
+        if selections.is_empty() {
+            return;
+        }
+
+        let snapshot = self.buffer.read(cx).snapshot(cx);
+        self.change_selections(None, window, cx, |s| {
+            s.select_ranges(selections.into_iter().map(|(start, end)| {
+                snapshot.clip_offset(start, Bias::Left)..snapshot.clip_offset(end, Bias::Right)
+            }));
+        });
+    }
 }
 
 fn get_uncommitted_diff_for_buffer(