item.rs

   1use crate::{
   2    pane::{self, Pane},
   3    persistence::model::ItemId,
   4    searchable::SearchableItemHandle,
   5    workspace_settings::{AutosaveSetting, WorkspaceSettings},
   6    DelayedDebouncedEditAction, FollowableViewRegistry, ItemNavHistory, SerializableItemRegistry,
   7    ToolbarItemLocation, ViewId, Workspace, WorkspaceId,
   8};
   9use anyhow::Result;
  10use client::{
  11    proto::{self, PeerId},
  12    Client,
  13};
  14use futures::{channel::mpsc, StreamExt};
  15use gpui::{
  16    AnyElement, AnyView, AppContext, Entity, EntityId, EventEmitter, FocusHandle, FocusableView,
  17    Font, HighlightStyle, Model, Pixels, Point, SharedString, Task, View, ViewContext, WeakView,
  18    WindowContext,
  19};
  20use project::{Project, ProjectEntryId, ProjectPath};
  21use schemars::JsonSchema;
  22use serde::{Deserialize, Serialize};
  23use settings::{Settings, SettingsLocation, SettingsSources};
  24use smallvec::SmallVec;
  25use std::{
  26    any::{Any, TypeId},
  27    cell::RefCell,
  28    ops::Range,
  29    rc::Rc,
  30    sync::Arc,
  31    time::Duration,
  32};
  33use theme::Theme;
  34use ui::{Color, Element as _, Icon, IntoElement, Label, LabelCommon};
  35use util::ResultExt;
  36
  37pub const LEADER_UPDATE_THROTTLE: Duration = Duration::from_millis(200);
  38
  39#[derive(Deserialize)]
  40pub struct ItemSettings {
  41    pub git_status: bool,
  42    pub close_position: ClosePosition,
  43    pub activate_on_close: ActivateOnClose,
  44    pub file_icons: bool,
  45}
  46
  47#[derive(Deserialize)]
  48pub struct PreviewTabsSettings {
  49    pub enabled: bool,
  50    pub enable_preview_from_file_finder: bool,
  51    pub enable_preview_from_code_navigation: bool,
  52}
  53
  54#[derive(Clone, Default, Serialize, Deserialize, JsonSchema)]
  55#[serde(rename_all = "lowercase")]
  56pub enum ClosePosition {
  57    Left,
  58    #[default]
  59    Right,
  60}
  61
  62#[derive(Clone, Default, Serialize, Deserialize, JsonSchema)]
  63#[serde(rename_all = "lowercase")]
  64pub enum ActivateOnClose {
  65    #[default]
  66    History,
  67    Neighbour,
  68}
  69
  70#[derive(Clone, Default, Serialize, Deserialize, JsonSchema)]
  71pub struct ItemSettingsContent {
  72    /// Whether to show the Git file status on a tab item.
  73    ///
  74    /// Default: false
  75    git_status: Option<bool>,
  76    /// Position of the close button in a tab.
  77    ///
  78    /// Default: right
  79    close_position: Option<ClosePosition>,
  80    /// Whether to show the file icon for a tab.
  81    ///
  82    /// Default: false
  83    file_icons: Option<bool>,
  84    /// What to do after closing the current tab.
  85    ///
  86    /// Default: history
  87    pub activate_on_close: Option<ActivateOnClose>,
  88}
  89
  90#[derive(Clone, Default, Serialize, Deserialize, JsonSchema)]
  91pub struct PreviewTabsSettingsContent {
  92    /// Whether to show opened editors as preview tabs.
  93    /// Preview tabs do not stay open, are reused until explicitly set to be kept open opened (via double-click or editing) and show file names in italic.
  94    ///
  95    /// Default: true
  96    enabled: Option<bool>,
  97    /// Whether to open tabs in preview mode when selected from the file finder.
  98    ///
  99    /// Default: false
 100    enable_preview_from_file_finder: Option<bool>,
 101    /// Whether a preview tab gets replaced when code navigation is used to navigate away from the tab.
 102    ///
 103    /// Default: false
 104    enable_preview_from_code_navigation: Option<bool>,
 105}
 106
 107impl Settings for ItemSettings {
 108    const KEY: Option<&'static str> = Some("tabs");
 109
 110    type FileContent = ItemSettingsContent;
 111
 112    fn load(sources: SettingsSources<Self::FileContent>, _: &mut AppContext) -> Result<Self> {
 113        sources.json_merge()
 114    }
 115}
 116
 117impl Settings for PreviewTabsSettings {
 118    const KEY: Option<&'static str> = Some("preview_tabs");
 119
 120    type FileContent = PreviewTabsSettingsContent;
 121
 122    fn load(sources: SettingsSources<Self::FileContent>, _: &mut AppContext) -> Result<Self> {
 123        sources.json_merge()
 124    }
 125}
 126
 127#[derive(Clone, Copy, Eq, PartialEq, Hash, Debug)]
 128pub enum ItemEvent {
 129    CloseItem,
 130    UpdateTab,
 131    UpdateBreadcrumbs,
 132    Edit,
 133}
 134
 135// TODO: Combine this with existing HighlightedText struct?
 136pub struct BreadcrumbText {
 137    pub text: String,
 138    pub highlights: Option<Vec<(Range<usize>, HighlightStyle)>>,
 139    pub font: Option<Font>,
 140}
 141
 142#[derive(Debug, Clone, Copy)]
 143pub struct TabContentParams {
 144    pub detail: Option<usize>,
 145    pub selected: bool,
 146    pub preview: bool,
 147}
 148
 149impl TabContentParams {
 150    /// Returns the text color to be used for the tab content.
 151    pub fn text_color(&self) -> Color {
 152        if self.selected {
 153            Color::Default
 154        } else {
 155            Color::Muted
 156        }
 157    }
 158}
 159
 160pub trait Item: FocusableView + EventEmitter<Self::Event> {
 161    type Event;
 162
 163    /// Returns the tab contents.
 164    ///
 165    /// By default this returns a [`Label`] that displays that text from
 166    /// `tab_content_text`.
 167    fn tab_content(&self, params: TabContentParams, cx: &WindowContext) -> AnyElement {
 168        let Some(text) = self.tab_content_text(cx) else {
 169            return gpui::Empty.into_any();
 170        };
 171
 172        Label::new(text)
 173            .color(params.text_color())
 174            .into_any_element()
 175    }
 176
 177    /// Returns the textual contents of the tab.
 178    ///
 179    /// Use this if you don't need to customize the tab contents.
 180    fn tab_content_text(&self, _cx: &WindowContext) -> Option<SharedString> {
 181        None
 182    }
 183
 184    fn tab_icon(&self, _cx: &WindowContext) -> Option<Icon> {
 185        None
 186    }
 187
 188    fn to_item_events(_event: &Self::Event, _f: impl FnMut(ItemEvent)) {}
 189
 190    fn deactivated(&mut self, _: &mut ViewContext<Self>) {}
 191    fn discarded(&self, _project: Model<Project>, _cx: &mut ViewContext<Self>) {}
 192    fn workspace_deactivated(&mut self, _: &mut ViewContext<Self>) {}
 193    fn navigate(&mut self, _: Box<dyn Any>, _: &mut ViewContext<Self>) -> bool {
 194        false
 195    }
 196    fn tab_tooltip_text(&self, _: &AppContext) -> Option<SharedString> {
 197        None
 198    }
 199    fn tab_description(&self, _: usize, _: &AppContext) -> Option<SharedString> {
 200        None
 201    }
 202
 203    fn telemetry_event_text(&self) -> Option<&'static str> {
 204        None
 205    }
 206
 207    /// (model id, Item)
 208    fn for_each_project_item(
 209        &self,
 210        _: &AppContext,
 211        _: &mut dyn FnMut(EntityId, &dyn project::Item),
 212    ) {
 213    }
 214    fn is_singleton(&self, _cx: &AppContext) -> bool {
 215        false
 216    }
 217    fn set_nav_history(&mut self, _: ItemNavHistory, _: &mut ViewContext<Self>) {}
 218    fn clone_on_split(
 219        &self,
 220        _workspace_id: Option<WorkspaceId>,
 221        _: &mut ViewContext<Self>,
 222    ) -> Option<View<Self>>
 223    where
 224        Self: Sized,
 225    {
 226        None
 227    }
 228    fn is_dirty(&self, _: &AppContext) -> bool {
 229        false
 230    }
 231    fn has_conflict(&self, _: &AppContext) -> bool {
 232        false
 233    }
 234    fn can_save(&self, _cx: &AppContext) -> bool {
 235        false
 236    }
 237    fn save(
 238        &mut self,
 239        _format: bool,
 240        _project: Model<Project>,
 241        _cx: &mut ViewContext<Self>,
 242    ) -> Task<Result<()>> {
 243        unimplemented!("save() must be implemented if can_save() returns true")
 244    }
 245    fn save_as(
 246        &mut self,
 247        _project: Model<Project>,
 248        _path: ProjectPath,
 249        _cx: &mut ViewContext<Self>,
 250    ) -> Task<Result<()>> {
 251        unimplemented!("save_as() must be implemented if can_save() returns true")
 252    }
 253    fn reload(
 254        &mut self,
 255        _project: Model<Project>,
 256        _cx: &mut ViewContext<Self>,
 257    ) -> Task<Result<()>> {
 258        unimplemented!("reload() must be implemented if can_save() returns true")
 259    }
 260
 261    fn act_as_type<'a>(
 262        &'a self,
 263        type_id: TypeId,
 264        self_handle: &'a View<Self>,
 265        _: &'a AppContext,
 266    ) -> Option<AnyView> {
 267        if TypeId::of::<Self>() == type_id {
 268            Some(self_handle.clone().into())
 269        } else {
 270            None
 271        }
 272    }
 273
 274    fn as_searchable(&self, _: &View<Self>) -> Option<Box<dyn SearchableItemHandle>> {
 275        None
 276    }
 277
 278    fn breadcrumb_location(&self) -> ToolbarItemLocation {
 279        ToolbarItemLocation::Hidden
 280    }
 281
 282    fn breadcrumbs(&self, _theme: &Theme, _cx: &AppContext) -> Option<Vec<BreadcrumbText>> {
 283        None
 284    }
 285
 286    fn added_to_workspace(&mut self, _workspace: &mut Workspace, _cx: &mut ViewContext<Self>) {}
 287
 288    fn show_toolbar(&self) -> bool {
 289        true
 290    }
 291
 292    fn pixel_position_of_cursor(&self, _: &AppContext) -> Option<Point<Pixels>> {
 293        None
 294    }
 295
 296    fn preserve_preview(&self, _cx: &AppContext) -> bool {
 297        false
 298    }
 299}
 300
 301pub trait SerializableItem: Item {
 302    fn serialized_item_kind() -> &'static str;
 303
 304    fn cleanup(
 305        workspace_id: WorkspaceId,
 306        alive_items: Vec<ItemId>,
 307        cx: &mut WindowContext,
 308    ) -> Task<Result<()>>;
 309
 310    fn deserialize(
 311        _project: Model<Project>,
 312        _workspace: WeakView<Workspace>,
 313        _workspace_id: WorkspaceId,
 314        _item_id: ItemId,
 315        _cx: &mut ViewContext<Pane>,
 316    ) -> Task<Result<View<Self>>>;
 317
 318    fn serialize(
 319        &mut self,
 320        workspace: &mut Workspace,
 321        item_id: ItemId,
 322        closing: bool,
 323        cx: &mut ViewContext<Self>,
 324    ) -> Option<Task<Result<()>>>;
 325
 326    fn should_serialize(&self, event: &Self::Event) -> bool;
 327}
 328
 329pub trait SerializableItemHandle: ItemHandle {
 330    fn serialized_item_kind(&self) -> &'static str;
 331    fn serialize(
 332        &self,
 333        workspace: &mut Workspace,
 334        closing: bool,
 335        cx: &mut WindowContext,
 336    ) -> Option<Task<Result<()>>>;
 337    fn should_serialize(&self, event: &dyn Any, cx: &AppContext) -> bool;
 338}
 339
 340impl<T> SerializableItemHandle for View<T>
 341where
 342    T: SerializableItem,
 343{
 344    fn serialized_item_kind(&self) -> &'static str {
 345        T::serialized_item_kind()
 346    }
 347
 348    fn serialize(
 349        &self,
 350        workspace: &mut Workspace,
 351        closing: bool,
 352        cx: &mut WindowContext,
 353    ) -> Option<Task<Result<()>>> {
 354        self.update(cx, |this, cx| {
 355            this.serialize(workspace, cx.entity_id().as_u64(), closing, cx)
 356        })
 357    }
 358
 359    fn should_serialize(&self, event: &dyn Any, cx: &AppContext) -> bool {
 360        event
 361            .downcast_ref::<T::Event>()
 362            .map_or(false, |event| self.read(cx).should_serialize(event))
 363    }
 364}
 365
 366pub trait ItemHandle: 'static + Send {
 367    fn subscribe_to_item_events(
 368        &self,
 369        cx: &mut WindowContext,
 370        handler: Box<dyn Fn(ItemEvent, &mut WindowContext)>,
 371    ) -> gpui::Subscription;
 372    fn focus_handle(&self, cx: &WindowContext) -> FocusHandle;
 373    fn tab_tooltip_text(&self, cx: &AppContext) -> Option<SharedString>;
 374    fn tab_description(&self, detail: usize, cx: &AppContext) -> Option<SharedString>;
 375    fn tab_content(&self, params: TabContentParams, cx: &WindowContext) -> AnyElement;
 376    fn tab_icon(&self, cx: &WindowContext) -> Option<Icon>;
 377    fn telemetry_event_text(&self, cx: &WindowContext) -> Option<&'static str>;
 378    fn dragged_tab_content(&self, params: TabContentParams, cx: &WindowContext) -> AnyElement;
 379    fn project_path(&self, cx: &AppContext) -> Option<ProjectPath>;
 380    fn project_entry_ids(&self, cx: &AppContext) -> SmallVec<[ProjectEntryId; 3]>;
 381    fn project_paths(&self, cx: &AppContext) -> SmallVec<[ProjectPath; 3]>;
 382    fn project_item_model_ids(&self, cx: &AppContext) -> SmallVec<[EntityId; 3]>;
 383    fn for_each_project_item(
 384        &self,
 385        _: &AppContext,
 386        _: &mut dyn FnMut(EntityId, &dyn project::Item),
 387    );
 388    fn is_singleton(&self, cx: &AppContext) -> bool;
 389    fn boxed_clone(&self) -> Box<dyn ItemHandle>;
 390    fn clone_on_split(
 391        &self,
 392        workspace_id: Option<WorkspaceId>,
 393        cx: &mut WindowContext,
 394    ) -> Option<Box<dyn ItemHandle>>;
 395    fn added_to_pane(
 396        &self,
 397        workspace: &mut Workspace,
 398        pane: View<Pane>,
 399        cx: &mut ViewContext<Workspace>,
 400    );
 401    fn deactivated(&self, cx: &mut WindowContext);
 402    fn discarded(&self, project: Model<Project>, cx: &mut WindowContext);
 403    fn workspace_deactivated(&self, cx: &mut WindowContext);
 404    fn navigate(&self, data: Box<dyn Any>, cx: &mut WindowContext) -> bool;
 405    fn item_id(&self) -> EntityId;
 406    fn to_any(&self) -> AnyView;
 407    fn is_dirty(&self, cx: &AppContext) -> bool;
 408    fn has_conflict(&self, cx: &AppContext) -> bool;
 409    fn can_save(&self, cx: &AppContext) -> bool;
 410    fn save(
 411        &self,
 412        format: bool,
 413        project: Model<Project>,
 414        cx: &mut WindowContext,
 415    ) -> Task<Result<()>>;
 416    fn save_as(
 417        &self,
 418        project: Model<Project>,
 419        path: ProjectPath,
 420        cx: &mut WindowContext,
 421    ) -> Task<Result<()>>;
 422    fn reload(&self, project: Model<Project>, cx: &mut WindowContext) -> Task<Result<()>>;
 423    fn act_as_type(&self, type_id: TypeId, cx: &AppContext) -> Option<AnyView>;
 424    fn to_followable_item_handle(&self, cx: &AppContext) -> Option<Box<dyn FollowableItemHandle>>;
 425    fn to_serializable_item_handle(
 426        &self,
 427        cx: &AppContext,
 428    ) -> Option<Box<dyn SerializableItemHandle>>;
 429    fn on_release(
 430        &self,
 431        cx: &mut AppContext,
 432        callback: Box<dyn FnOnce(&mut AppContext) + Send>,
 433    ) -> gpui::Subscription;
 434    fn to_searchable_item_handle(&self, cx: &AppContext) -> Option<Box<dyn SearchableItemHandle>>;
 435    fn breadcrumb_location(&self, cx: &AppContext) -> ToolbarItemLocation;
 436    fn breadcrumbs(&self, theme: &Theme, cx: &AppContext) -> Option<Vec<BreadcrumbText>>;
 437    fn show_toolbar(&self, cx: &AppContext) -> bool;
 438    fn pixel_position_of_cursor(&self, cx: &AppContext) -> Option<Point<Pixels>>;
 439    fn downgrade_item(&self) -> Box<dyn WeakItemHandle>;
 440    fn workspace_settings<'a>(&self, cx: &'a AppContext) -> &'a WorkspaceSettings;
 441    fn preserve_preview(&self, cx: &AppContext) -> bool;
 442}
 443
 444pub trait WeakItemHandle: Send + Sync {
 445    fn id(&self) -> EntityId;
 446    fn boxed_clone(&self) -> Box<dyn WeakItemHandle>;
 447    fn upgrade(&self) -> Option<Box<dyn ItemHandle>>;
 448}
 449
 450impl dyn ItemHandle {
 451    pub fn downcast<V: 'static>(&self) -> Option<View<V>> {
 452        self.to_any().downcast().ok()
 453    }
 454
 455    pub fn act_as<V: 'static>(&self, cx: &AppContext) -> Option<View<V>> {
 456        self.act_as_type(TypeId::of::<V>(), cx)
 457            .and_then(|t| t.downcast().ok())
 458    }
 459}
 460
 461impl<T: Item> ItemHandle for View<T> {
 462    fn subscribe_to_item_events(
 463        &self,
 464        cx: &mut WindowContext,
 465        handler: Box<dyn Fn(ItemEvent, &mut WindowContext)>,
 466    ) -> gpui::Subscription {
 467        cx.subscribe(self, move |_, event, cx| {
 468            T::to_item_events(event, |item_event| handler(item_event, cx));
 469        })
 470    }
 471
 472    fn focus_handle(&self, cx: &WindowContext) -> FocusHandle {
 473        self.focus_handle(cx)
 474    }
 475
 476    fn tab_tooltip_text(&self, cx: &AppContext) -> Option<SharedString> {
 477        self.read(cx).tab_tooltip_text(cx)
 478    }
 479
 480    fn telemetry_event_text(&self, cx: &WindowContext) -> Option<&'static str> {
 481        self.read(cx).telemetry_event_text()
 482    }
 483
 484    fn tab_description(&self, detail: usize, cx: &AppContext) -> Option<SharedString> {
 485        self.read(cx).tab_description(detail, cx)
 486    }
 487
 488    fn tab_content(&self, params: TabContentParams, cx: &WindowContext) -> AnyElement {
 489        self.read(cx).tab_content(params, cx)
 490    }
 491
 492    fn tab_icon(&self, cx: &WindowContext) -> Option<Icon> {
 493        self.read(cx).tab_icon(cx)
 494    }
 495
 496    fn dragged_tab_content(&self, params: TabContentParams, cx: &WindowContext) -> AnyElement {
 497        self.read(cx).tab_content(
 498            TabContentParams {
 499                selected: true,
 500                ..params
 501            },
 502            cx,
 503        )
 504    }
 505
 506    fn project_path(&self, cx: &AppContext) -> Option<ProjectPath> {
 507        let this = self.read(cx);
 508        let mut result = None;
 509        if this.is_singleton(cx) {
 510            this.for_each_project_item(cx, &mut |_, item| {
 511                result = item.project_path(cx);
 512            });
 513        }
 514        result
 515    }
 516
 517    fn workspace_settings<'a>(&self, cx: &'a AppContext) -> &'a WorkspaceSettings {
 518        if let Some(project_path) = self.project_path(cx) {
 519            WorkspaceSettings::get(
 520                Some(SettingsLocation {
 521                    worktree_id: project_path.worktree_id,
 522                    path: &project_path.path,
 523                }),
 524                cx,
 525            )
 526        } else {
 527            WorkspaceSettings::get_global(cx)
 528        }
 529    }
 530
 531    fn project_entry_ids(&self, cx: &AppContext) -> SmallVec<[ProjectEntryId; 3]> {
 532        let mut result = SmallVec::new();
 533        self.read(cx).for_each_project_item(cx, &mut |_, item| {
 534            if let Some(id) = item.entry_id(cx) {
 535                result.push(id);
 536            }
 537        });
 538        result
 539    }
 540
 541    fn project_paths(&self, cx: &AppContext) -> SmallVec<[ProjectPath; 3]> {
 542        let mut result = SmallVec::new();
 543        self.read(cx).for_each_project_item(cx, &mut |_, item| {
 544            if let Some(id) = item.project_path(cx) {
 545                result.push(id);
 546            }
 547        });
 548        result
 549    }
 550
 551    fn project_item_model_ids(&self, cx: &AppContext) -> SmallVec<[EntityId; 3]> {
 552        let mut result = SmallVec::new();
 553        self.read(cx).for_each_project_item(cx, &mut |id, _| {
 554            result.push(id);
 555        });
 556        result
 557    }
 558
 559    fn for_each_project_item(
 560        &self,
 561        cx: &AppContext,
 562        f: &mut dyn FnMut(EntityId, &dyn project::Item),
 563    ) {
 564        self.read(cx).for_each_project_item(cx, f)
 565    }
 566
 567    fn is_singleton(&self, cx: &AppContext) -> bool {
 568        self.read(cx).is_singleton(cx)
 569    }
 570
 571    fn boxed_clone(&self) -> Box<dyn ItemHandle> {
 572        Box::new(self.clone())
 573    }
 574
 575    fn clone_on_split(
 576        &self,
 577        workspace_id: Option<WorkspaceId>,
 578        cx: &mut WindowContext,
 579    ) -> Option<Box<dyn ItemHandle>> {
 580        self.update(cx, |item, cx| item.clone_on_split(workspace_id, cx))
 581            .map(|handle| Box::new(handle) as Box<dyn ItemHandle>)
 582    }
 583
 584    fn added_to_pane(
 585        &self,
 586        workspace: &mut Workspace,
 587        pane: View<Pane>,
 588        cx: &mut ViewContext<Workspace>,
 589    ) {
 590        let weak_item = self.downgrade();
 591        let history = pane.read(cx).nav_history_for_item(self);
 592        self.update(cx, |this, cx| {
 593            this.set_nav_history(history, cx);
 594            this.added_to_workspace(workspace, cx);
 595        });
 596
 597        if let Some(serializable_item) = self.to_serializable_item_handle(cx) {
 598            workspace
 599                .enqueue_item_serialization(serializable_item)
 600                .log_err();
 601        }
 602
 603        if workspace
 604            .panes_by_item
 605            .insert(self.item_id(), pane.downgrade())
 606            .is_none()
 607        {
 608            let mut pending_autosave = DelayedDebouncedEditAction::new();
 609            let (pending_update_tx, mut pending_update_rx) = mpsc::unbounded();
 610            let pending_update = Rc::new(RefCell::new(None));
 611
 612            let mut send_follower_updates = None;
 613            if let Some(item) = self.to_followable_item_handle(cx) {
 614                let is_project_item = item.is_project_item(cx);
 615                let item = item.downgrade();
 616
 617                send_follower_updates = Some(cx.spawn({
 618                    let pending_update = pending_update.clone();
 619                    |workspace, mut cx| async move {
 620                        while let Some(mut leader_id) = pending_update_rx.next().await {
 621                            while let Ok(Some(id)) = pending_update_rx.try_next() {
 622                                leader_id = id;
 623                            }
 624
 625                            workspace.update(&mut cx, |workspace, cx| {
 626                                let Some(item) = item.upgrade() else { return };
 627                                workspace.update_followers(
 628                                    is_project_item,
 629                                    proto::update_followers::Variant::UpdateView(
 630                                        proto::UpdateView {
 631                                            id: item
 632                                                .remote_id(workspace.client(), cx)
 633                                                .map(|id| id.to_proto()),
 634                                            variant: pending_update.borrow_mut().take(),
 635                                            leader_id,
 636                                        },
 637                                    ),
 638                                    cx,
 639                                );
 640                            })?;
 641                            cx.background_executor().timer(LEADER_UPDATE_THROTTLE).await;
 642                        }
 643                        anyhow::Ok(())
 644                    }
 645                }));
 646            }
 647
 648            let mut event_subscription = Some(cx.subscribe(
 649                self,
 650                move |workspace, item: View<T>, event, cx| {
 651                    let pane = if let Some(pane) = workspace
 652                        .panes_by_item
 653                        .get(&item.item_id())
 654                        .and_then(|pane| pane.upgrade())
 655                    {
 656                        pane
 657                    } else {
 658                        return;
 659                    };
 660
 661                    if let Some(item) = item.to_followable_item_handle(cx) {
 662                        let leader_id = workspace.leader_for_pane(&pane);
 663
 664                        if let Some(leader_id) = leader_id {
 665                            if let Some(FollowEvent::Unfollow) = item.to_follow_event(event) {
 666                                workspace.unfollow(leader_id, cx);
 667                            }
 668                        }
 669
 670                        if item.focus_handle(cx).contains_focused(cx) {
 671                            item.add_event_to_update_proto(
 672                                event,
 673                                &mut pending_update.borrow_mut(),
 674                                cx,
 675                            );
 676                            pending_update_tx.unbounded_send(leader_id).ok();
 677                        }
 678                    }
 679
 680                    if let Some(item) = item.to_serializable_item_handle(cx) {
 681                        if item.should_serialize(event, cx) {
 682                            workspace.enqueue_item_serialization(item).ok();
 683                        }
 684                    }
 685
 686                    T::to_item_events(event, |event| match event {
 687                        ItemEvent::CloseItem => {
 688                            pane.update(cx, |pane, cx| {
 689                                pane.close_item_by_id(item.item_id(), crate::SaveIntent::Close, cx)
 690                            })
 691                            .detach_and_log_err(cx);
 692                        }
 693
 694                        ItemEvent::UpdateTab => {
 695                            pane.update(cx, |_, cx| {
 696                                cx.emit(pane::Event::ChangeItemTitle);
 697                                cx.notify();
 698                            });
 699                        }
 700
 701                        ItemEvent::Edit => {
 702                            let autosave = item.workspace_settings(cx).autosave;
 703
 704                            if let AutosaveSetting::AfterDelay { milliseconds } = autosave {
 705                                let delay = Duration::from_millis(milliseconds);
 706                                let item = item.clone();
 707                                pending_autosave.fire_new(delay, cx, move |workspace, cx| {
 708                                    Pane::autosave_item(&item, workspace.project().clone(), cx)
 709                                });
 710                            }
 711                            pane.update(cx, |pane, cx| pane.handle_item_edit(item.item_id(), cx));
 712                        }
 713
 714                        _ => {}
 715                    });
 716                },
 717            ));
 718
 719            cx.on_blur(&self.focus_handle(cx), move |workspace, cx| {
 720                if let Some(item) = weak_item.upgrade() {
 721                    if item.workspace_settings(cx).autosave == AutosaveSetting::OnFocusChange {
 722                        Pane::autosave_item(&item, workspace.project.clone(), cx)
 723                            .detach_and_log_err(cx);
 724                    }
 725                }
 726            })
 727            .detach();
 728
 729            let item_id = self.item_id();
 730            cx.observe_release(self, move |workspace, _, _| {
 731                workspace.panes_by_item.remove(&item_id);
 732                event_subscription.take();
 733                send_follower_updates.take();
 734            })
 735            .detach();
 736        }
 737
 738        cx.defer(|workspace, cx| {
 739            workspace.serialize_workspace(cx);
 740        });
 741    }
 742
 743    fn discarded(&self, project: Model<Project>, cx: &mut WindowContext) {
 744        self.update(cx, |this, cx| this.discarded(project, cx));
 745    }
 746
 747    fn deactivated(&self, cx: &mut WindowContext) {
 748        self.update(cx, |this, cx| this.deactivated(cx));
 749    }
 750
 751    fn workspace_deactivated(&self, cx: &mut WindowContext) {
 752        self.update(cx, |this, cx| this.workspace_deactivated(cx));
 753    }
 754
 755    fn navigate(&self, data: Box<dyn Any>, cx: &mut WindowContext) -> bool {
 756        self.update(cx, |this, cx| this.navigate(data, cx))
 757    }
 758
 759    fn item_id(&self) -> EntityId {
 760        self.entity_id()
 761    }
 762
 763    fn to_any(&self) -> AnyView {
 764        self.clone().into()
 765    }
 766
 767    fn is_dirty(&self, cx: &AppContext) -> bool {
 768        self.read(cx).is_dirty(cx)
 769    }
 770
 771    fn has_conflict(&self, cx: &AppContext) -> bool {
 772        self.read(cx).has_conflict(cx)
 773    }
 774
 775    fn can_save(&self, cx: &AppContext) -> bool {
 776        self.read(cx).can_save(cx)
 777    }
 778
 779    fn save(
 780        &self,
 781        format: bool,
 782        project: Model<Project>,
 783        cx: &mut WindowContext,
 784    ) -> Task<Result<()>> {
 785        self.update(cx, |item, cx| item.save(format, project, cx))
 786    }
 787
 788    fn save_as(
 789        &self,
 790        project: Model<Project>,
 791        path: ProjectPath,
 792        cx: &mut WindowContext,
 793    ) -> Task<anyhow::Result<()>> {
 794        self.update(cx, |item, cx| item.save_as(project, path, cx))
 795    }
 796
 797    fn reload(&self, project: Model<Project>, cx: &mut WindowContext) -> Task<Result<()>> {
 798        self.update(cx, |item, cx| item.reload(project, cx))
 799    }
 800
 801    fn act_as_type<'a>(&'a self, type_id: TypeId, cx: &'a AppContext) -> Option<AnyView> {
 802        self.read(cx).act_as_type(type_id, self, cx)
 803    }
 804
 805    fn to_followable_item_handle(&self, cx: &AppContext) -> Option<Box<dyn FollowableItemHandle>> {
 806        FollowableViewRegistry::to_followable_view(self.clone(), cx)
 807    }
 808
 809    fn on_release(
 810        &self,
 811        cx: &mut AppContext,
 812        callback: Box<dyn FnOnce(&mut AppContext) + Send>,
 813    ) -> gpui::Subscription {
 814        cx.observe_release(self, move |_, cx| callback(cx))
 815    }
 816
 817    fn to_searchable_item_handle(&self, cx: &AppContext) -> Option<Box<dyn SearchableItemHandle>> {
 818        self.read(cx).as_searchable(self)
 819    }
 820
 821    fn breadcrumb_location(&self, cx: &AppContext) -> ToolbarItemLocation {
 822        self.read(cx).breadcrumb_location()
 823    }
 824
 825    fn breadcrumbs(&self, theme: &Theme, cx: &AppContext) -> Option<Vec<BreadcrumbText>> {
 826        self.read(cx).breadcrumbs(theme, cx)
 827    }
 828
 829    fn show_toolbar(&self, cx: &AppContext) -> bool {
 830        self.read(cx).show_toolbar()
 831    }
 832
 833    fn pixel_position_of_cursor(&self, cx: &AppContext) -> Option<Point<Pixels>> {
 834        self.read(cx).pixel_position_of_cursor(cx)
 835    }
 836
 837    fn downgrade_item(&self) -> Box<dyn WeakItemHandle> {
 838        Box::new(self.downgrade())
 839    }
 840
 841    fn to_serializable_item_handle(
 842        &self,
 843        cx: &AppContext,
 844    ) -> Option<Box<dyn SerializableItemHandle>> {
 845        SerializableItemRegistry::view_to_serializable_item_handle(self.to_any(), cx)
 846    }
 847
 848    fn preserve_preview(&self, cx: &AppContext) -> bool {
 849        self.read(cx).preserve_preview(cx)
 850    }
 851}
 852
 853impl From<Box<dyn ItemHandle>> for AnyView {
 854    fn from(val: Box<dyn ItemHandle>) -> Self {
 855        val.to_any()
 856    }
 857}
 858
 859impl From<&Box<dyn ItemHandle>> for AnyView {
 860    fn from(val: &Box<dyn ItemHandle>) -> Self {
 861        val.to_any()
 862    }
 863}
 864
 865impl Clone for Box<dyn ItemHandle> {
 866    fn clone(&self) -> Box<dyn ItemHandle> {
 867        self.boxed_clone()
 868    }
 869}
 870
 871impl<T: Item> WeakItemHandle for WeakView<T> {
 872    fn id(&self) -> EntityId {
 873        self.entity_id()
 874    }
 875
 876    fn boxed_clone(&self) -> Box<dyn WeakItemHandle> {
 877        Box::new(self.clone())
 878    }
 879
 880    fn upgrade(&self) -> Option<Box<dyn ItemHandle>> {
 881        self.upgrade().map(|v| Box::new(v) as Box<dyn ItemHandle>)
 882    }
 883}
 884
 885pub trait ProjectItem: Item {
 886    type Item: project::Item;
 887
 888    fn for_project_item(
 889        project: Model<Project>,
 890        item: Model<Self::Item>,
 891        cx: &mut ViewContext<Self>,
 892    ) -> Self
 893    where
 894        Self: Sized;
 895}
 896
 897#[derive(Debug)]
 898pub enum FollowEvent {
 899    Unfollow,
 900}
 901
 902pub enum Dedup {
 903    KeepExisting,
 904    ReplaceExisting,
 905}
 906
 907pub trait FollowableItem: Item {
 908    fn remote_id(&self) -> Option<ViewId>;
 909    fn to_state_proto(&self, cx: &WindowContext) -> Option<proto::view::Variant>;
 910    fn from_state_proto(
 911        project: View<Workspace>,
 912        id: ViewId,
 913        state: &mut Option<proto::view::Variant>,
 914        cx: &mut WindowContext,
 915    ) -> Option<Task<Result<View<Self>>>>;
 916    fn to_follow_event(event: &Self::Event) -> Option<FollowEvent>;
 917    fn add_event_to_update_proto(
 918        &self,
 919        event: &Self::Event,
 920        update: &mut Option<proto::update_view::Variant>,
 921        cx: &WindowContext,
 922    ) -> bool;
 923    fn apply_update_proto(
 924        &mut self,
 925        project: &Model<Project>,
 926        message: proto::update_view::Variant,
 927        cx: &mut ViewContext<Self>,
 928    ) -> Task<Result<()>>;
 929    fn is_project_item(&self, cx: &WindowContext) -> bool;
 930    fn set_leader_peer_id(&mut self, leader_peer_id: Option<PeerId>, cx: &mut ViewContext<Self>);
 931    fn dedup(&self, existing: &Self, cx: &WindowContext) -> Option<Dedup>;
 932}
 933
 934pub trait FollowableItemHandle: ItemHandle {
 935    fn remote_id(&self, client: &Arc<Client>, cx: &WindowContext) -> Option<ViewId>;
 936    fn downgrade(&self) -> Box<dyn WeakFollowableItemHandle>;
 937    fn set_leader_peer_id(&self, leader_peer_id: Option<PeerId>, cx: &mut WindowContext);
 938    fn to_state_proto(&self, cx: &WindowContext) -> Option<proto::view::Variant>;
 939    fn add_event_to_update_proto(
 940        &self,
 941        event: &dyn Any,
 942        update: &mut Option<proto::update_view::Variant>,
 943        cx: &WindowContext,
 944    ) -> bool;
 945    fn to_follow_event(&self, event: &dyn Any) -> Option<FollowEvent>;
 946    fn apply_update_proto(
 947        &self,
 948        project: &Model<Project>,
 949        message: proto::update_view::Variant,
 950        cx: &mut WindowContext,
 951    ) -> Task<Result<()>>;
 952    fn is_project_item(&self, cx: &WindowContext) -> bool;
 953    fn dedup(&self, existing: &dyn FollowableItemHandle, cx: &WindowContext) -> Option<Dedup>;
 954}
 955
 956impl<T: FollowableItem> FollowableItemHandle for View<T> {
 957    fn remote_id(&self, client: &Arc<Client>, cx: &WindowContext) -> Option<ViewId> {
 958        self.read(cx).remote_id().or_else(|| {
 959            client.peer_id().map(|creator| ViewId {
 960                creator,
 961                id: self.item_id().as_u64(),
 962            })
 963        })
 964    }
 965
 966    fn downgrade(&self) -> Box<dyn WeakFollowableItemHandle> {
 967        Box::new(self.downgrade())
 968    }
 969
 970    fn set_leader_peer_id(&self, leader_peer_id: Option<PeerId>, cx: &mut WindowContext) {
 971        self.update(cx, |this, cx| this.set_leader_peer_id(leader_peer_id, cx))
 972    }
 973
 974    fn to_state_proto(&self, cx: &WindowContext) -> Option<proto::view::Variant> {
 975        self.read(cx).to_state_proto(cx)
 976    }
 977
 978    fn add_event_to_update_proto(
 979        &self,
 980        event: &dyn Any,
 981        update: &mut Option<proto::update_view::Variant>,
 982        cx: &WindowContext,
 983    ) -> bool {
 984        if let Some(event) = event.downcast_ref() {
 985            self.read(cx).add_event_to_update_proto(event, update, cx)
 986        } else {
 987            false
 988        }
 989    }
 990
 991    fn to_follow_event(&self, event: &dyn Any) -> Option<FollowEvent> {
 992        T::to_follow_event(event.downcast_ref()?)
 993    }
 994
 995    fn apply_update_proto(
 996        &self,
 997        project: &Model<Project>,
 998        message: proto::update_view::Variant,
 999        cx: &mut WindowContext,
1000    ) -> Task<Result<()>> {
1001        self.update(cx, |this, cx| this.apply_update_proto(project, message, cx))
1002    }
1003
1004    fn is_project_item(&self, cx: &WindowContext) -> bool {
1005        self.read(cx).is_project_item(cx)
1006    }
1007
1008    fn dedup(&self, existing: &dyn FollowableItemHandle, cx: &WindowContext) -> Option<Dedup> {
1009        let existing = existing.to_any().downcast::<T>().ok()?;
1010        self.read(cx).dedup(existing.read(cx), cx)
1011    }
1012}
1013
1014pub trait WeakFollowableItemHandle: Send + Sync {
1015    fn upgrade(&self) -> Option<Box<dyn FollowableItemHandle>>;
1016}
1017
1018impl<T: FollowableItem> WeakFollowableItemHandle for WeakView<T> {
1019    fn upgrade(&self) -> Option<Box<dyn FollowableItemHandle>> {
1020        Some(Box::new(self.upgrade()?))
1021    }
1022}
1023
1024#[cfg(any(test, feature = "test-support"))]
1025pub mod test {
1026    use super::{Item, ItemEvent, SerializableItem, TabContentParams};
1027    use crate::{ItemId, ItemNavHistory, Pane, Workspace, WorkspaceId};
1028    use gpui::{
1029        AnyElement, AppContext, Context as _, EntityId, EventEmitter, FocusableView,
1030        InteractiveElement, IntoElement, Model, Render, SharedString, Task, View, ViewContext,
1031        VisualContext, WeakView,
1032    };
1033    use project::{Project, ProjectEntryId, ProjectPath, WorktreeId};
1034    use std::{any::Any, cell::Cell, path::Path};
1035
1036    pub struct TestProjectItem {
1037        pub entry_id: Option<ProjectEntryId>,
1038        pub project_path: Option<ProjectPath>,
1039    }
1040
1041    pub struct TestItem {
1042        pub workspace_id: Option<WorkspaceId>,
1043        pub state: String,
1044        pub label: String,
1045        pub save_count: usize,
1046        pub save_as_count: usize,
1047        pub reload_count: usize,
1048        pub is_dirty: bool,
1049        pub is_singleton: bool,
1050        pub has_conflict: bool,
1051        pub project_items: Vec<Model<TestProjectItem>>,
1052        pub nav_history: Option<ItemNavHistory>,
1053        pub tab_descriptions: Option<Vec<&'static str>>,
1054        pub tab_detail: Cell<Option<usize>>,
1055        serialize: Option<Box<dyn Fn() -> Option<Task<anyhow::Result<()>>>>>,
1056        focus_handle: gpui::FocusHandle,
1057    }
1058
1059    impl project::Item for TestProjectItem {
1060        fn try_open(
1061            _project: &Model<Project>,
1062            _path: &ProjectPath,
1063            _cx: &mut AppContext,
1064        ) -> Option<Task<gpui::Result<Model<Self>>>> {
1065            None
1066        }
1067
1068        fn entry_id(&self, _: &AppContext) -> Option<ProjectEntryId> {
1069            self.entry_id
1070        }
1071
1072        fn project_path(&self, _: &AppContext) -> Option<ProjectPath> {
1073            self.project_path.clone()
1074        }
1075    }
1076
1077    pub enum TestItemEvent {
1078        Edit,
1079    }
1080
1081    impl TestProjectItem {
1082        pub fn new(id: u64, path: &str, cx: &mut AppContext) -> Model<Self> {
1083            let entry_id = Some(ProjectEntryId::from_proto(id));
1084            let project_path = Some(ProjectPath {
1085                worktree_id: WorktreeId::from_usize(0),
1086                path: Path::new(path).into(),
1087            });
1088            cx.new_model(|_| Self {
1089                entry_id,
1090                project_path,
1091            })
1092        }
1093
1094        pub fn new_untitled(cx: &mut AppContext) -> Model<Self> {
1095            cx.new_model(|_| Self {
1096                project_path: None,
1097                entry_id: None,
1098            })
1099        }
1100    }
1101
1102    impl TestItem {
1103        pub fn new(cx: &mut ViewContext<Self>) -> Self {
1104            Self {
1105                state: String::new(),
1106                label: String::new(),
1107                save_count: 0,
1108                save_as_count: 0,
1109                reload_count: 0,
1110                is_dirty: false,
1111                has_conflict: false,
1112                project_items: Vec::new(),
1113                is_singleton: true,
1114                nav_history: None,
1115                tab_descriptions: None,
1116                tab_detail: Default::default(),
1117                workspace_id: Default::default(),
1118                focus_handle: cx.focus_handle(),
1119                serialize: None,
1120            }
1121        }
1122
1123        pub fn new_deserialized(id: WorkspaceId, cx: &mut ViewContext<Self>) -> Self {
1124            let mut this = Self::new(cx);
1125            this.workspace_id = Some(id);
1126            this
1127        }
1128
1129        pub fn with_label(mut self, state: &str) -> Self {
1130            self.label = state.to_string();
1131            self
1132        }
1133
1134        pub fn with_singleton(mut self, singleton: bool) -> Self {
1135            self.is_singleton = singleton;
1136            self
1137        }
1138
1139        pub fn with_dirty(mut self, dirty: bool) -> Self {
1140            self.is_dirty = dirty;
1141            self
1142        }
1143
1144        pub fn with_conflict(mut self, has_conflict: bool) -> Self {
1145            self.has_conflict = has_conflict;
1146            self
1147        }
1148
1149        pub fn with_project_items(mut self, items: &[Model<TestProjectItem>]) -> Self {
1150            self.project_items.clear();
1151            self.project_items.extend(items.iter().cloned());
1152            self
1153        }
1154
1155        pub fn with_serialize(
1156            mut self,
1157            serialize: impl Fn() -> Option<Task<anyhow::Result<()>>> + 'static,
1158        ) -> Self {
1159            self.serialize = Some(Box::new(serialize));
1160            self
1161        }
1162
1163        pub fn set_state(&mut self, state: String, cx: &mut ViewContext<Self>) {
1164            self.push_to_nav_history(cx);
1165            self.state = state;
1166        }
1167
1168        fn push_to_nav_history(&mut self, cx: &mut ViewContext<Self>) {
1169            if let Some(history) = &mut self.nav_history {
1170                history.push(Some(Box::new(self.state.clone())), cx);
1171            }
1172        }
1173    }
1174
1175    impl Render for TestItem {
1176        fn render(&mut self, cx: &mut ViewContext<Self>) -> impl IntoElement {
1177            gpui::div().track_focus(&self.focus_handle(cx))
1178        }
1179    }
1180
1181    impl EventEmitter<ItemEvent> for TestItem {}
1182
1183    impl FocusableView for TestItem {
1184        fn focus_handle(&self, _: &AppContext) -> gpui::FocusHandle {
1185            self.focus_handle.clone()
1186        }
1187    }
1188
1189    impl Item for TestItem {
1190        type Event = ItemEvent;
1191
1192        fn to_item_events(event: &Self::Event, mut f: impl FnMut(ItemEvent)) {
1193            f(*event)
1194        }
1195
1196        fn tab_description(&self, detail: usize, _: &AppContext) -> Option<SharedString> {
1197            self.tab_descriptions.as_ref().and_then(|descriptions| {
1198                let description = *descriptions.get(detail).or_else(|| descriptions.last())?;
1199                Some(description.into())
1200            })
1201        }
1202
1203        fn telemetry_event_text(&self) -> Option<&'static str> {
1204            None
1205        }
1206
1207        fn tab_content(
1208            &self,
1209            params: TabContentParams,
1210            _cx: &ui::prelude::WindowContext,
1211        ) -> AnyElement {
1212            self.tab_detail.set(params.detail);
1213            gpui::div().into_any_element()
1214        }
1215
1216        fn for_each_project_item(
1217            &self,
1218            cx: &AppContext,
1219            f: &mut dyn FnMut(EntityId, &dyn project::Item),
1220        ) {
1221            self.project_items
1222                .iter()
1223                .for_each(|item| f(item.entity_id(), item.read(cx)))
1224        }
1225
1226        fn is_singleton(&self, _: &AppContext) -> bool {
1227            self.is_singleton
1228        }
1229
1230        fn set_nav_history(&mut self, history: ItemNavHistory, _: &mut ViewContext<Self>) {
1231            self.nav_history = Some(history);
1232        }
1233
1234        fn navigate(&mut self, state: Box<dyn Any>, _: &mut ViewContext<Self>) -> bool {
1235            let state = *state.downcast::<String>().unwrap_or_default();
1236            if state != self.state {
1237                self.state = state;
1238                true
1239            } else {
1240                false
1241            }
1242        }
1243
1244        fn deactivated(&mut self, cx: &mut ViewContext<Self>) {
1245            self.push_to_nav_history(cx);
1246        }
1247
1248        fn clone_on_split(
1249            &self,
1250            _workspace_id: Option<WorkspaceId>,
1251            cx: &mut ViewContext<Self>,
1252        ) -> Option<View<Self>>
1253        where
1254            Self: Sized,
1255        {
1256            Some(cx.new_view(|cx| Self {
1257                state: self.state.clone(),
1258                label: self.label.clone(),
1259                save_count: self.save_count,
1260                save_as_count: self.save_as_count,
1261                reload_count: self.reload_count,
1262                is_dirty: self.is_dirty,
1263                is_singleton: self.is_singleton,
1264                has_conflict: self.has_conflict,
1265                project_items: self.project_items.clone(),
1266                nav_history: None,
1267                tab_descriptions: None,
1268                tab_detail: Default::default(),
1269                workspace_id: self.workspace_id,
1270                focus_handle: cx.focus_handle(),
1271                serialize: None,
1272            }))
1273        }
1274
1275        fn is_dirty(&self, _: &AppContext) -> bool {
1276            self.is_dirty
1277        }
1278
1279        fn has_conflict(&self, _: &AppContext) -> bool {
1280            self.has_conflict
1281        }
1282
1283        fn can_save(&self, cx: &AppContext) -> bool {
1284            !self.project_items.is_empty()
1285                && self
1286                    .project_items
1287                    .iter()
1288                    .all(|item| item.read(cx).entry_id.is_some())
1289        }
1290
1291        fn save(
1292            &mut self,
1293            _: bool,
1294            _: Model<Project>,
1295            _: &mut ViewContext<Self>,
1296        ) -> Task<anyhow::Result<()>> {
1297            self.save_count += 1;
1298            self.is_dirty = false;
1299            Task::ready(Ok(()))
1300        }
1301
1302        fn save_as(
1303            &mut self,
1304            _: Model<Project>,
1305            _: ProjectPath,
1306            _: &mut ViewContext<Self>,
1307        ) -> Task<anyhow::Result<()>> {
1308            self.save_as_count += 1;
1309            self.is_dirty = false;
1310            Task::ready(Ok(()))
1311        }
1312
1313        fn reload(
1314            &mut self,
1315            _: Model<Project>,
1316            _: &mut ViewContext<Self>,
1317        ) -> Task<anyhow::Result<()>> {
1318            self.reload_count += 1;
1319            self.is_dirty = false;
1320            Task::ready(Ok(()))
1321        }
1322    }
1323
1324    impl SerializableItem for TestItem {
1325        fn serialized_item_kind() -> &'static str {
1326            "TestItem"
1327        }
1328
1329        fn deserialize(
1330            _project: Model<Project>,
1331            _workspace: WeakView<Workspace>,
1332            workspace_id: WorkspaceId,
1333            _item_id: ItemId,
1334            cx: &mut ViewContext<Pane>,
1335        ) -> Task<anyhow::Result<View<Self>>> {
1336            let view = cx.new_view(|cx| Self::new_deserialized(workspace_id, cx));
1337            Task::ready(Ok(view))
1338        }
1339
1340        fn cleanup(
1341            _workspace_id: WorkspaceId,
1342            _alive_items: Vec<ItemId>,
1343            _cx: &mut ui::WindowContext,
1344        ) -> Task<anyhow::Result<()>> {
1345            Task::ready(Ok(()))
1346        }
1347
1348        fn serialize(
1349            &mut self,
1350            _workspace: &mut Workspace,
1351            _item_id: ItemId,
1352            _closing: bool,
1353            _cx: &mut ViewContext<Self>,
1354        ) -> Option<Task<anyhow::Result<()>>> {
1355            if let Some(serialize) = self.serialize.take() {
1356                let result = serialize();
1357                self.serialize = Some(serialize);
1358                result
1359            } else {
1360                None
1361            }
1362        }
1363
1364        fn should_serialize(&self, _event: &Self::Event) -> bool {
1365            false
1366        }
1367    }
1368}