pane.rs

   1use super::{ItemHandle, SplitDirection};
   2use crate::{toolbar::Toolbar, Item, NewFile, NewSearch, NewTerminal, WeakItemHandle, Workspace};
   3use anyhow::Result;
   4use collections::{HashMap, HashSet, VecDeque};
   5use context_menu::{ContextMenu, ContextMenuItem};
   6use drag_and_drop::{DragAndDrop, Draggable};
   7use futures::StreamExt;
   8use gpui::{
   9    actions,
  10    color::Color,
  11    elements::*,
  12    geometry::{
  13        rect::RectF,
  14        vector::{vec2f, Vector2F},
  15    },
  16    impl_actions, impl_internal_actions,
  17    platform::{CursorStyle, NavigationDirection},
  18    AnyViewHandle, AnyWeakViewHandle, AppContext, AsyncAppContext, Entity, EventContext,
  19    ModelHandle, MouseButton, MutableAppContext, PromptLevel, Quad, RenderContext, Task, View,
  20    ViewContext, ViewHandle, WeakViewHandle,
  21};
  22use project::{Project, ProjectEntryId, ProjectPath};
  23use serde::Deserialize;
  24use settings::{Autosave, Settings};
  25use std::{any::Any, cell::RefCell, cmp, mem, path::Path, rc::Rc};
  26use theme::Theme;
  27use util::ResultExt;
  28
  29#[derive(Clone, Deserialize, PartialEq)]
  30pub struct ActivateItem(pub usize);
  31
  32actions!(
  33    pane,
  34    [
  35        ActivatePrevItem,
  36        ActivateNextItem,
  37        ActivateLastItem,
  38        CloseActiveItem,
  39        CloseInactiveItems,
  40        ReopenClosedItem,
  41        SplitLeft,
  42        SplitUp,
  43        SplitRight,
  44        SplitDown,
  45    ]
  46);
  47
  48#[derive(Clone, PartialEq)]
  49pub struct CloseItem {
  50    pub item_id: usize,
  51    pub pane: WeakViewHandle<Pane>,
  52}
  53
  54#[derive(Clone, PartialEq)]
  55pub struct MoveItem {
  56    pub item_id: usize,
  57    pub from: WeakViewHandle<Pane>,
  58    pub to: WeakViewHandle<Pane>,
  59    pub destination_index: usize,
  60}
  61
  62#[derive(Clone, Deserialize, PartialEq)]
  63pub struct GoBack {
  64    #[serde(skip_deserializing)]
  65    pub pane: Option<WeakViewHandle<Pane>>,
  66}
  67
  68#[derive(Clone, Deserialize, PartialEq)]
  69pub struct GoForward {
  70    #[serde(skip_deserializing)]
  71    pub pane: Option<WeakViewHandle<Pane>>,
  72}
  73
  74#[derive(Clone, PartialEq)]
  75pub struct DeploySplitMenu {
  76    position: Vector2F,
  77}
  78
  79#[derive(Clone, PartialEq)]
  80pub struct DeployNewMenu {
  81    position: Vector2F,
  82}
  83
  84impl_actions!(pane, [GoBack, GoForward, ActivateItem]);
  85impl_internal_actions!(pane, [CloseItem, DeploySplitMenu, DeployNewMenu, MoveItem]);
  86
  87const MAX_NAVIGATION_HISTORY_LEN: usize = 1024;
  88
  89pub fn init(cx: &mut MutableAppContext) {
  90    cx.add_action(|pane: &mut Pane, action: &ActivateItem, cx| {
  91        pane.activate_item(action.0, true, true, cx);
  92    });
  93    cx.add_action(|pane: &mut Pane, _: &ActivateLastItem, cx| {
  94        pane.activate_item(pane.items.len() - 1, true, true, cx);
  95    });
  96    cx.add_action(|pane: &mut Pane, _: &ActivatePrevItem, cx| {
  97        pane.activate_prev_item(cx);
  98    });
  99    cx.add_action(|pane: &mut Pane, _: &ActivateNextItem, cx| {
 100        pane.activate_next_item(cx);
 101    });
 102    cx.add_async_action(Pane::close_active_item);
 103    cx.add_async_action(Pane::close_inactive_items);
 104    cx.add_async_action(|workspace: &mut Workspace, action: &CloseItem, cx| {
 105        let pane = action.pane.upgrade(cx)?;
 106        let task = Pane::close_item(workspace, pane, action.item_id, cx);
 107        Some(cx.foreground().spawn(async move {
 108            task.await?;
 109            Ok(())
 110        }))
 111    });
 112    cx.add_action(
 113        |workspace,
 114         MoveItem {
 115             from,
 116             to,
 117             item_id,
 118             destination_index,
 119         },
 120         cx| {
 121            // Get item handle to move
 122            let from = if let Some(from) = from.upgrade(cx) {
 123                from
 124            } else {
 125                return;
 126            };
 127
 128            // Add item to new pane at given index
 129            let to = if let Some(to) = to.upgrade(cx) {
 130                to
 131            } else {
 132                return;
 133            };
 134
 135            Pane::move_item(workspace, from, to, *item_id, *destination_index, cx)
 136        },
 137    );
 138    cx.add_action(|pane: &mut Pane, _: &SplitLeft, cx| pane.split(SplitDirection::Left, cx));
 139    cx.add_action(|pane: &mut Pane, _: &SplitUp, cx| pane.split(SplitDirection::Up, cx));
 140    cx.add_action(|pane: &mut Pane, _: &SplitRight, cx| pane.split(SplitDirection::Right, cx));
 141    cx.add_action(|pane: &mut Pane, _: &SplitDown, cx| pane.split(SplitDirection::Down, cx));
 142    cx.add_action(Pane::deploy_split_menu);
 143    cx.add_action(Pane::deploy_new_menu);
 144    cx.add_action(|workspace: &mut Workspace, _: &ReopenClosedItem, cx| {
 145        Pane::reopen_closed_item(workspace, cx).detach();
 146    });
 147    cx.add_action(|workspace: &mut Workspace, action: &GoBack, cx| {
 148        Pane::go_back(
 149            workspace,
 150            action
 151                .pane
 152                .as_ref()
 153                .and_then(|weak_handle| weak_handle.upgrade(cx)),
 154            cx,
 155        )
 156        .detach();
 157    });
 158    cx.add_action(|workspace: &mut Workspace, action: &GoForward, cx| {
 159        Pane::go_forward(
 160            workspace,
 161            action
 162                .pane
 163                .as_ref()
 164                .and_then(|weak_handle| weak_handle.upgrade(cx)),
 165            cx,
 166        )
 167        .detach();
 168    });
 169}
 170
 171pub enum Event {
 172    Focused,
 173    ActivateItem { local: bool },
 174    Remove,
 175    RemoveItem { item_id: usize },
 176    Split(SplitDirection),
 177    ChangeItemTitle,
 178}
 179
 180pub struct Pane {
 181    items: Vec<Box<dyn ItemHandle>>,
 182    is_active: bool,
 183    active_item_index: usize,
 184    last_focused_view: Option<AnyWeakViewHandle>,
 185    autoscroll: bool,
 186    nav_history: Rc<RefCell<NavHistory>>,
 187    toolbar: ViewHandle<Toolbar>,
 188    context_menu: ViewHandle<ContextMenu>,
 189}
 190
 191pub struct ItemNavHistory {
 192    history: Rc<RefCell<NavHistory>>,
 193    item: Rc<dyn WeakItemHandle>,
 194}
 195
 196struct NavHistory {
 197    mode: NavigationMode,
 198    backward_stack: VecDeque<NavigationEntry>,
 199    forward_stack: VecDeque<NavigationEntry>,
 200    closed_stack: VecDeque<NavigationEntry>,
 201    paths_by_item: HashMap<usize, ProjectPath>,
 202    pane: WeakViewHandle<Pane>,
 203}
 204
 205#[derive(Copy, Clone)]
 206enum NavigationMode {
 207    Normal,
 208    GoingBack,
 209    GoingForward,
 210    ClosingItem,
 211    ReopeningClosedItem,
 212    Disabled,
 213}
 214
 215impl Default for NavigationMode {
 216    fn default() -> Self {
 217        Self::Normal
 218    }
 219}
 220
 221pub struct NavigationEntry {
 222    pub item: Rc<dyn WeakItemHandle>,
 223    pub data: Option<Box<dyn Any>>,
 224}
 225
 226struct DraggedItem {
 227    item: Box<dyn ItemHandle>,
 228    pane: WeakViewHandle<Pane>,
 229}
 230
 231pub enum ReorderBehavior {
 232    None,
 233    MoveAfterActive,
 234    MoveToIndex(usize),
 235}
 236
 237impl Pane {
 238    pub fn new(cx: &mut ViewContext<Self>) -> Self {
 239        let handle = cx.weak_handle();
 240        let context_menu = cx.add_view(ContextMenu::new);
 241        Self {
 242            items: Vec::new(),
 243            is_active: true,
 244            active_item_index: 0,
 245            last_focused_view: None,
 246            autoscroll: false,
 247            nav_history: Rc::new(RefCell::new(NavHistory {
 248                mode: NavigationMode::Normal,
 249                backward_stack: Default::default(),
 250                forward_stack: Default::default(),
 251                closed_stack: Default::default(),
 252                paths_by_item: Default::default(),
 253                pane: handle.clone(),
 254            })),
 255            toolbar: cx.add_view(|_| Toolbar::new(handle)),
 256            context_menu,
 257        }
 258    }
 259
 260    pub fn set_active(&mut self, is_active: bool, cx: &mut ViewContext<Self>) {
 261        self.is_active = is_active;
 262        cx.notify();
 263    }
 264
 265    pub fn nav_history_for_item<T: Item>(&self, item: &ViewHandle<T>) -> ItemNavHistory {
 266        ItemNavHistory {
 267            history: self.nav_history.clone(),
 268            item: Rc::new(item.downgrade()),
 269        }
 270    }
 271
 272    pub fn go_back(
 273        workspace: &mut Workspace,
 274        pane: Option<ViewHandle<Pane>>,
 275        cx: &mut ViewContext<Workspace>,
 276    ) -> Task<()> {
 277        Self::navigate_history(
 278            workspace,
 279            pane.unwrap_or_else(|| workspace.active_pane().clone()),
 280            NavigationMode::GoingBack,
 281            cx,
 282        )
 283    }
 284
 285    pub fn go_forward(
 286        workspace: &mut Workspace,
 287        pane: Option<ViewHandle<Pane>>,
 288        cx: &mut ViewContext<Workspace>,
 289    ) -> Task<()> {
 290        Self::navigate_history(
 291            workspace,
 292            pane.unwrap_or_else(|| workspace.active_pane().clone()),
 293            NavigationMode::GoingForward,
 294            cx,
 295        )
 296    }
 297
 298    pub fn reopen_closed_item(
 299        workspace: &mut Workspace,
 300        cx: &mut ViewContext<Workspace>,
 301    ) -> Task<()> {
 302        Self::navigate_history(
 303            workspace,
 304            workspace.active_pane().clone(),
 305            NavigationMode::ReopeningClosedItem,
 306            cx,
 307        )
 308    }
 309
 310    pub fn disable_history(&mut self) {
 311        self.nav_history.borrow_mut().disable();
 312    }
 313
 314    pub fn enable_history(&mut self) {
 315        self.nav_history.borrow_mut().enable();
 316    }
 317
 318    pub fn can_navigate_backward(&self) -> bool {
 319        !self.nav_history.borrow().backward_stack.is_empty()
 320    }
 321
 322    pub fn can_navigate_forward(&self) -> bool {
 323        !self.nav_history.borrow().forward_stack.is_empty()
 324    }
 325
 326    fn history_updated(&mut self, cx: &mut ViewContext<Self>) {
 327        self.toolbar.update(cx, |_, cx| cx.notify());
 328    }
 329
 330    fn navigate_history(
 331        workspace: &mut Workspace,
 332        pane: ViewHandle<Pane>,
 333        mode: NavigationMode,
 334        cx: &mut ViewContext<Workspace>,
 335    ) -> Task<()> {
 336        cx.focus(pane.clone());
 337
 338        let to_load = pane.update(cx, |pane, cx| {
 339            loop {
 340                // Retrieve the weak item handle from the history.
 341                let entry = pane.nav_history.borrow_mut().pop(mode, cx)?;
 342
 343                // If the item is still present in this pane, then activate it.
 344                if let Some(index) = entry
 345                    .item
 346                    .upgrade(cx)
 347                    .and_then(|v| pane.index_for_item(v.as_ref()))
 348                {
 349                    let prev_active_item_index = pane.active_item_index;
 350                    pane.nav_history.borrow_mut().set_mode(mode);
 351                    pane.activate_item(index, true, true, cx);
 352                    pane.nav_history
 353                        .borrow_mut()
 354                        .set_mode(NavigationMode::Normal);
 355
 356                    let mut navigated = prev_active_item_index != pane.active_item_index;
 357                    if let Some(data) = entry.data {
 358                        navigated |= pane.active_item()?.navigate(data, cx);
 359                    }
 360
 361                    if navigated {
 362                        break None;
 363                    }
 364                }
 365                // If the item is no longer present in this pane, then retrieve its
 366                // project path in order to reopen it.
 367                else {
 368                    break pane
 369                        .nav_history
 370                        .borrow()
 371                        .paths_by_item
 372                        .get(&entry.item.id())
 373                        .cloned()
 374                        .map(|project_path| (project_path, entry));
 375                }
 376            }
 377        });
 378
 379        if let Some((project_path, entry)) = to_load {
 380            // If the item was no longer present, then load it again from its previous path.
 381            let pane = pane.downgrade();
 382            let task = workspace.load_path(project_path, cx);
 383            cx.spawn(|workspace, mut cx| async move {
 384                let task = task.await;
 385                if let Some(pane) = pane.upgrade(&cx) {
 386                    let mut navigated = false;
 387                    if let Some((project_entry_id, build_item)) = task.log_err() {
 388                        let prev_active_item_id = pane.update(&mut cx, |pane, _| {
 389                            pane.nav_history.borrow_mut().set_mode(mode);
 390                            pane.active_item().map(|p| p.id())
 391                        });
 392
 393                        let item = workspace.update(&mut cx, |workspace, cx| {
 394                            Self::open_item(
 395                                workspace,
 396                                pane.clone(),
 397                                project_entry_id,
 398                                true,
 399                                cx,
 400                                build_item,
 401                            )
 402                        });
 403
 404                        pane.update(&mut cx, |pane, cx| {
 405                            navigated |= Some(item.id()) != prev_active_item_id;
 406                            pane.nav_history
 407                                .borrow_mut()
 408                                .set_mode(NavigationMode::Normal);
 409                            if let Some(data) = entry.data {
 410                                navigated |= item.navigate(data, cx);
 411                            }
 412                        });
 413                    }
 414
 415                    if !navigated {
 416                        workspace
 417                            .update(&mut cx, |workspace, cx| {
 418                                Self::navigate_history(workspace, pane, mode, cx)
 419                            })
 420                            .await;
 421                    }
 422                }
 423            })
 424        } else {
 425            Task::ready(())
 426        }
 427    }
 428
 429    pub(crate) fn open_item(
 430        workspace: &mut Workspace,
 431        pane: ViewHandle<Pane>,
 432        project_entry_id: ProjectEntryId,
 433        focus_item: bool,
 434        cx: &mut ViewContext<Workspace>,
 435        build_item: impl FnOnce(&mut ViewContext<Pane>) -> Box<dyn ItemHandle>,
 436    ) -> Box<dyn ItemHandle> {
 437        let existing_item = pane.update(cx, |pane, cx| {
 438            for item in pane.items.iter() {
 439                if item.project_path(cx).is_some()
 440                    && item.project_entry_ids(cx).as_slice() == [project_entry_id]
 441                {
 442                    let item = item.boxed_clone();
 443                    return Some(item);
 444                }
 445            }
 446            None
 447        });
 448
 449        // Even if the item exists, we re-add it to reorder it after the active item.
 450        // We may revisit this behavior after adding an "activation history" for pane items.
 451        let item = existing_item.unwrap_or_else(|| pane.update(cx, |_, cx| build_item(cx)));
 452        Pane::add_item(workspace, &pane, item.clone(), true, focus_item, None, cx);
 453        item
 454    }
 455
 456    pub(crate) fn add_item(
 457        workspace: &mut Workspace,
 458        pane: &ViewHandle<Pane>,
 459        item: Box<dyn ItemHandle>,
 460        activate_pane: bool,
 461        focus_item: bool,
 462        destination_index: Option<usize>,
 463        cx: &mut ViewContext<Workspace>,
 464    ) {
 465        // If no destination index is specified, add or move the item after the active item.
 466        let mut insertion_index = {
 467            let pane = pane.read(cx);
 468            cmp::min(
 469                if let Some(destination_index) = destination_index {
 470                    destination_index
 471                } else {
 472                    pane.active_item_index + 1
 473                },
 474                pane.items.len(),
 475            )
 476        };
 477
 478        item.added_to_pane(workspace, pane.clone(), cx);
 479
 480        // Does the item already exist?
 481        if let Some(existing_item_index) = pane.read(cx).items.iter().position(|existing_item| {
 482            let existing_item_entry_ids = existing_item.project_entry_ids(cx);
 483            let added_item_entry_ids = item.project_entry_ids(cx);
 484            let entries_match = !existing_item_entry_ids.is_empty()
 485                && existing_item_entry_ids == added_item_entry_ids;
 486
 487            existing_item.id() == item.id() || entries_match
 488        }) {
 489            // If the item already exists, move it to the desired destination and activate it
 490            pane.update(cx, |pane, cx| {
 491                if existing_item_index != insertion_index {
 492                    cx.reparent(&item);
 493                    let existing_item_is_active = existing_item_index == pane.active_item_index;
 494
 495                    // If the caller didn't specify a destination and the added item is already
 496                    // the active one, don't move it
 497                    if existing_item_is_active && destination_index.is_none() {
 498                        insertion_index = existing_item_index;
 499                    } else {
 500                        pane.items.remove(existing_item_index);
 501                        if existing_item_index < pane.active_item_index {
 502                            pane.active_item_index -= 1;
 503                        }
 504                        insertion_index = insertion_index.min(pane.items.len());
 505
 506                        pane.items.insert(insertion_index, item.clone());
 507
 508                        if existing_item_is_active {
 509                            pane.active_item_index = insertion_index;
 510                        } else if insertion_index <= pane.active_item_index {
 511                            pane.active_item_index += 1;
 512                        }
 513                    }
 514
 515                    cx.notify();
 516                }
 517
 518                pane.activate_item(insertion_index, activate_pane, focus_item, cx);
 519            });
 520        } else {
 521            pane.update(cx, |pane, cx| {
 522                cx.reparent(&item);
 523                pane.items.insert(insertion_index, item);
 524                if insertion_index <= pane.active_item_index {
 525                    pane.active_item_index += 1;
 526                }
 527
 528                pane.activate_item(insertion_index, activate_pane, focus_item, cx);
 529                cx.notify();
 530            });
 531        }
 532    }
 533
 534    pub fn items(&self) -> impl Iterator<Item = &Box<dyn ItemHandle>> {
 535        self.items.iter()
 536    }
 537
 538    pub fn items_of_type<T: View>(&self) -> impl '_ + Iterator<Item = ViewHandle<T>> {
 539        self.items
 540            .iter()
 541            .filter_map(|item| item.to_any().downcast())
 542    }
 543
 544    pub fn active_item(&self) -> Option<Box<dyn ItemHandle>> {
 545        self.items.get(self.active_item_index).cloned()
 546    }
 547
 548    pub fn item_for_entry(
 549        &self,
 550        entry_id: ProjectEntryId,
 551        cx: &AppContext,
 552    ) -> Option<Box<dyn ItemHandle>> {
 553        self.items.iter().find_map(|item| {
 554            if item.is_singleton(cx) && item.project_entry_ids(cx).as_slice() == [entry_id] {
 555                Some(item.boxed_clone())
 556            } else {
 557                None
 558            }
 559        })
 560    }
 561
 562    pub fn index_for_item(&self, item: &dyn ItemHandle) -> Option<usize> {
 563        self.items.iter().position(|i| i.id() == item.id())
 564    }
 565
 566    pub fn activate_item(
 567        &mut self,
 568        index: usize,
 569        activate_pane: bool,
 570        focus_item: bool,
 571        cx: &mut ViewContext<Self>,
 572    ) {
 573        use NavigationMode::{GoingBack, GoingForward};
 574        if index < self.items.len() {
 575            let prev_active_item_ix = mem::replace(&mut self.active_item_index, index);
 576            if prev_active_item_ix != self.active_item_index
 577                || matches!(self.nav_history.borrow().mode, GoingBack | GoingForward)
 578            {
 579                if let Some(prev_item) = self.items.get(prev_active_item_ix) {
 580                    prev_item.deactivated(cx);
 581                }
 582                cx.emit(Event::ActivateItem {
 583                    local: activate_pane,
 584                });
 585            }
 586            self.update_toolbar(cx);
 587            if focus_item {
 588                self.focus_active_item(cx);
 589            }
 590            if activate_pane {
 591                cx.emit(Event::Focused);
 592            }
 593            self.autoscroll = true;
 594            cx.notify();
 595        }
 596    }
 597
 598    pub fn activate_prev_item(&mut self, cx: &mut ViewContext<Self>) {
 599        let mut index = self.active_item_index;
 600        if index > 0 {
 601            index -= 1;
 602        } else if !self.items.is_empty() {
 603            index = self.items.len() - 1;
 604        }
 605        self.activate_item(index, true, true, cx);
 606    }
 607
 608    pub fn activate_next_item(&mut self, cx: &mut ViewContext<Self>) {
 609        let mut index = self.active_item_index;
 610        if index + 1 < self.items.len() {
 611            index += 1;
 612        } else {
 613            index = 0;
 614        }
 615        self.activate_item(index, true, true, cx);
 616    }
 617
 618    pub fn close_active_item(
 619        workspace: &mut Workspace,
 620        _: &CloseActiveItem,
 621        cx: &mut ViewContext<Workspace>,
 622    ) -> Option<Task<Result<()>>> {
 623        let pane_handle = workspace.active_pane().clone();
 624        let pane = pane_handle.read(cx);
 625        if pane.items.is_empty() {
 626            None
 627        } else {
 628            let item_id_to_close = pane.items[pane.active_item_index].id();
 629            let task = Self::close_items(workspace, pane_handle, cx, move |item_id| {
 630                item_id == item_id_to_close
 631            });
 632            Some(cx.foreground().spawn(async move {
 633                task.await?;
 634                Ok(())
 635            }))
 636        }
 637    }
 638
 639    pub fn close_inactive_items(
 640        workspace: &mut Workspace,
 641        _: &CloseInactiveItems,
 642        cx: &mut ViewContext<Workspace>,
 643    ) -> Option<Task<Result<()>>> {
 644        let pane_handle = workspace.active_pane().clone();
 645        let pane = pane_handle.read(cx);
 646        if pane.items.is_empty() {
 647            None
 648        } else {
 649            let active_item_id = pane.items[pane.active_item_index].id();
 650            let task =
 651                Self::close_items(workspace, pane_handle, cx, move |id| id != active_item_id);
 652            Some(cx.foreground().spawn(async move {
 653                task.await?;
 654                Ok(())
 655            }))
 656        }
 657    }
 658
 659    pub fn close_item(
 660        workspace: &mut Workspace,
 661        pane: ViewHandle<Pane>,
 662        item_id_to_close: usize,
 663        cx: &mut ViewContext<Workspace>,
 664    ) -> Task<Result<bool>> {
 665        Self::close_items(workspace, pane, cx, move |view_id| {
 666            view_id == item_id_to_close
 667        })
 668    }
 669
 670    pub fn close_items(
 671        workspace: &mut Workspace,
 672        pane: ViewHandle<Pane>,
 673        cx: &mut ViewContext<Workspace>,
 674        should_close: impl 'static + Fn(usize) -> bool,
 675    ) -> Task<Result<bool>> {
 676        let project = workspace.project().clone();
 677
 678        // Find the items to close.
 679        let mut items_to_close = Vec::new();
 680        for item in &pane.read(cx).items {
 681            if should_close(item.id()) {
 682                items_to_close.push(item.boxed_clone());
 683            }
 684        }
 685
 686        // If a buffer is open both in a singleton editor and in a multibuffer, make sure
 687        // to focus the singleton buffer when prompting to save that buffer, as opposed
 688        // to focusing the multibuffer, because this gives the user a more clear idea
 689        // of what content they would be saving.
 690        items_to_close.sort_by_key(|item| !item.is_singleton(cx));
 691
 692        cx.spawn(|workspace, mut cx| async move {
 693            let mut saved_project_entry_ids = HashSet::default();
 694            for item in items_to_close.clone() {
 695                // Find the item's current index and its set of project entries. Avoid
 696                // storing these in advance, in case they have changed since this task
 697                // was started.
 698                let (item_ix, mut project_entry_ids) = pane.read_with(&cx, |pane, cx| {
 699                    (pane.index_for_item(&*item), item.project_entry_ids(cx))
 700                });
 701                let item_ix = if let Some(ix) = item_ix {
 702                    ix
 703                } else {
 704                    continue;
 705                };
 706
 707                // If an item hasn't yet been associated with a project entry, then always
 708                // prompt to save it before closing it. Otherwise, check if the item has
 709                // any project entries that are not open anywhere else in the workspace,
 710                // AND that the user has not already been prompted to save. If there are
 711                // any such project entries, prompt the user to save this item.
 712                let should_save = if project_entry_ids.is_empty() {
 713                    true
 714                } else {
 715                    workspace.read_with(&cx, |workspace, cx| {
 716                        for item in workspace.items(cx) {
 717                            if !items_to_close
 718                                .iter()
 719                                .any(|item_to_close| item_to_close.id() == item.id())
 720                            {
 721                                let other_project_entry_ids = item.project_entry_ids(cx);
 722                                project_entry_ids
 723                                    .retain(|id| !other_project_entry_ids.contains(id));
 724                            }
 725                        }
 726                    });
 727                    project_entry_ids
 728                        .iter()
 729                        .any(|id| saved_project_entry_ids.insert(*id))
 730                };
 731
 732                if should_save
 733                    && !Self::save_item(project.clone(), &pane, item_ix, &*item, true, &mut cx)
 734                        .await?
 735                {
 736                    break;
 737                }
 738
 739                // Remove the item from the pane.
 740                pane.update(&mut cx, |pane, cx| {
 741                    if let Some(item_ix) = pane.items.iter().position(|i| i.id() == item.id()) {
 742                        pane.remove_item(item_ix, cx);
 743                    }
 744                });
 745            }
 746
 747            pane.update(&mut cx, |_, cx| cx.notify());
 748            Ok(true)
 749        })
 750    }
 751
 752    fn remove_item(&mut self, item_ix: usize, cx: &mut ViewContext<Self>) {
 753        if item_ix == self.active_item_index {
 754            // Activate the previous item if possible.
 755            // This returns the user to the previously opened tab if they closed
 756            // a new item they just navigated to.
 757            if item_ix > 0 {
 758                self.activate_prev_item(cx);
 759            } else if item_ix + 1 < self.items.len() {
 760                self.activate_next_item(cx);
 761            }
 762        }
 763
 764        let item = self.items.remove(item_ix);
 765        cx.emit(Event::RemoveItem { item_id: item.id() });
 766        if self.items.is_empty() {
 767            item.deactivated(cx);
 768            self.update_toolbar(cx);
 769            cx.emit(Event::Remove);
 770        }
 771
 772        if item_ix < self.active_item_index {
 773            self.active_item_index -= 1;
 774        }
 775
 776        self.nav_history
 777            .borrow_mut()
 778            .set_mode(NavigationMode::ClosingItem);
 779        item.deactivated(cx);
 780        self.nav_history
 781            .borrow_mut()
 782            .set_mode(NavigationMode::Normal);
 783
 784        if let Some(path) = item.project_path(cx) {
 785            self.nav_history
 786                .borrow_mut()
 787                .paths_by_item
 788                .insert(item.id(), path);
 789        } else {
 790            self.nav_history
 791                .borrow_mut()
 792                .paths_by_item
 793                .remove(&item.id());
 794        }
 795
 796        cx.notify();
 797    }
 798
 799    pub async fn save_item(
 800        project: ModelHandle<Project>,
 801        pane: &ViewHandle<Pane>,
 802        item_ix: usize,
 803        item: &dyn ItemHandle,
 804        should_prompt_for_save: bool,
 805        cx: &mut AsyncAppContext,
 806    ) -> Result<bool> {
 807        const CONFLICT_MESSAGE: &str =
 808            "This file has changed on disk since you started editing it. Do you want to overwrite it?";
 809        const DIRTY_MESSAGE: &str = "This file contains unsaved edits. Do you want to save it?";
 810
 811        let (has_conflict, is_dirty, can_save, is_singleton) = cx.read(|cx| {
 812            (
 813                item.has_conflict(cx),
 814                item.is_dirty(cx),
 815                item.can_save(cx),
 816                item.is_singleton(cx),
 817            )
 818        });
 819
 820        if has_conflict && can_save {
 821            let mut answer = pane.update(cx, |pane, cx| {
 822                pane.activate_item(item_ix, true, true, cx);
 823                cx.prompt(
 824                    PromptLevel::Warning,
 825                    CONFLICT_MESSAGE,
 826                    &["Overwrite", "Discard", "Cancel"],
 827                )
 828            });
 829            match answer.next().await {
 830                Some(0) => cx.update(|cx| item.save(project, cx)).await?,
 831                Some(1) => cx.update(|cx| item.reload(project, cx)).await?,
 832                _ => return Ok(false),
 833            }
 834        } else if is_dirty && (can_save || is_singleton) {
 835            let will_autosave = cx.read(|cx| {
 836                matches!(
 837                    cx.global::<Settings>().autosave,
 838                    Autosave::OnFocusChange | Autosave::OnWindowChange
 839                ) && Self::can_autosave_item(&*item, cx)
 840            });
 841            let should_save = if should_prompt_for_save && !will_autosave {
 842                let mut answer = pane.update(cx, |pane, cx| {
 843                    pane.activate_item(item_ix, true, true, cx);
 844                    cx.prompt(
 845                        PromptLevel::Warning,
 846                        DIRTY_MESSAGE,
 847                        &["Save", "Don't Save", "Cancel"],
 848                    )
 849                });
 850                match answer.next().await {
 851                    Some(0) => true,
 852                    Some(1) => false,
 853                    _ => return Ok(false),
 854                }
 855            } else {
 856                true
 857            };
 858
 859            if should_save {
 860                if can_save {
 861                    cx.update(|cx| item.save(project, cx)).await?;
 862                } else if is_singleton {
 863                    let start_abs_path = project
 864                        .read_with(cx, |project, cx| {
 865                            let worktree = project.visible_worktrees(cx).next()?;
 866                            Some(worktree.read(cx).as_local()?.abs_path().to_path_buf())
 867                        })
 868                        .unwrap_or_else(|| Path::new("").into());
 869
 870                    let mut abs_path = cx.update(|cx| cx.prompt_for_new_path(&start_abs_path));
 871                    if let Some(abs_path) = abs_path.next().await.flatten() {
 872                        cx.update(|cx| item.save_as(project, abs_path, cx)).await?;
 873                    } else {
 874                        return Ok(false);
 875                    }
 876                }
 877            }
 878        }
 879        Ok(true)
 880    }
 881
 882    fn can_autosave_item(item: &dyn ItemHandle, cx: &AppContext) -> bool {
 883        let is_deleted = item.project_entry_ids(cx).is_empty();
 884        item.is_dirty(cx) && !item.has_conflict(cx) && item.can_save(cx) && !is_deleted
 885    }
 886
 887    pub fn autosave_item(
 888        item: &dyn ItemHandle,
 889        project: ModelHandle<Project>,
 890        cx: &mut MutableAppContext,
 891    ) -> Task<Result<()>> {
 892        if Self::can_autosave_item(item, cx) {
 893            item.save(project, cx)
 894        } else {
 895            Task::ready(Ok(()))
 896        }
 897    }
 898
 899    pub fn focus_active_item(&mut self, cx: &mut ViewContext<Self>) {
 900        if let Some(active_item) = self.active_item() {
 901            cx.focus(active_item);
 902        }
 903    }
 904
 905    fn move_item(
 906        workspace: &mut Workspace,
 907        from: ViewHandle<Pane>,
 908        to: ViewHandle<Pane>,
 909        item_to_move: usize,
 910        destination_index: usize,
 911        cx: &mut ViewContext<Workspace>,
 912    ) {
 913        let item_to_move = from
 914            .read(cx)
 915            .items()
 916            .enumerate()
 917            .find(|(_, item_handle)| item_handle.id() == item_to_move);
 918
 919        if item_to_move.is_none() {
 920            log::warn!("Tried to move item handle which was not in `from` pane. Maybe tab was closed during drop");
 921            return;
 922        }
 923
 924        let (item_ix, item_handle) = item_to_move.unwrap();
 925        // This automatically removes duplicate items in the pane
 926        Pane::add_item(
 927            workspace,
 928            &to,
 929            item_handle.clone(),
 930            true,
 931            true,
 932            Some(destination_index),
 933            cx,
 934        );
 935
 936        if from != to {
 937            // Close item from previous pane
 938            from.update(cx, |from, cx| {
 939                from.remove_item(item_ix, cx);
 940            });
 941        }
 942
 943        cx.focus(to);
 944    }
 945
 946    pub fn split(&mut self, direction: SplitDirection, cx: &mut ViewContext<Self>) {
 947        cx.emit(Event::Split(direction));
 948    }
 949
 950    fn deploy_split_menu(&mut self, action: &DeploySplitMenu, cx: &mut ViewContext<Self>) {
 951        self.context_menu.update(cx, |menu, cx| {
 952            menu.show(
 953                action.position,
 954                vec![
 955                    ContextMenuItem::item("Split Right", SplitRight),
 956                    ContextMenuItem::item("Split Left", SplitLeft),
 957                    ContextMenuItem::item("Split Up", SplitUp),
 958                    ContextMenuItem::item("Split Down", SplitDown),
 959                ],
 960                cx,
 961            );
 962        });
 963    }
 964
 965    fn deploy_new_menu(&mut self, action: &DeployNewMenu, cx: &mut ViewContext<Self>) {
 966        self.context_menu.update(cx, |menu, cx| {
 967            menu.show(
 968                action.position,
 969                vec![
 970                    ContextMenuItem::item("New File", NewFile),
 971                    ContextMenuItem::item("New Terminal", NewTerminal),
 972                    ContextMenuItem::item("New Search", NewSearch),
 973                ],
 974                cx,
 975            );
 976        });
 977    }
 978
 979    pub fn toolbar(&self) -> &ViewHandle<Toolbar> {
 980        &self.toolbar
 981    }
 982
 983    fn update_toolbar(&mut self, cx: &mut ViewContext<Self>) {
 984        let active_item = self
 985            .items
 986            .get(self.active_item_index)
 987            .map(|item| item.as_ref());
 988        self.toolbar.update(cx, |toolbar, cx| {
 989            toolbar.set_active_pane_item(active_item, cx);
 990        });
 991    }
 992
 993    fn render_tab_bar(&mut self, cx: &mut RenderContext<Self>) -> impl Element {
 994        let theme = cx.global::<Settings>().theme.clone();
 995        let filler_index = self.items.len();
 996
 997        enum Tabs {}
 998        enum Tab {}
 999        enum Filler {}
1000        let pane = cx.handle();
1001        MouseEventHandler::new::<Tabs, _, _>(0, cx, |_, cx| {
1002            let autoscroll = if mem::take(&mut self.autoscroll) {
1003                Some(self.active_item_index)
1004            } else {
1005                None
1006            };
1007
1008            let pane_active = self.is_active;
1009
1010            let mut row = Flex::row().scrollable::<Tabs, _>(1, autoscroll, cx);
1011            for (ix, (item, detail)) in self
1012                .items
1013                .iter()
1014                .cloned()
1015                .zip(self.tab_details(cx))
1016                .enumerate()
1017            {
1018                let detail = if detail == 0 { None } else { Some(detail) };
1019                let tab_active = ix == self.active_item_index;
1020
1021                row.add_child({
1022                    MouseEventHandler::new::<Tab, _, _>(ix, cx, {
1023                        let item = item.clone();
1024                        let pane = pane.clone();
1025                        let detail = detail.clone();
1026
1027                        let theme = cx.global::<Settings>().theme.clone();
1028
1029                        move |mouse_state, cx| {
1030                            let tab_style =
1031                                theme.workspace.tab_bar.tab_style(pane_active, tab_active);
1032                            let hovered = mouse_state.hovered;
1033                            Self::render_tab(
1034                                &item,
1035                                pane,
1036                                detail,
1037                                hovered,
1038                                Self::tab_overlay_color(hovered, theme.as_ref(), cx),
1039                                tab_style,
1040                                cx,
1041                            )
1042                        }
1043                    })
1044                    .with_cursor_style(if pane_active && tab_active {
1045                        CursorStyle::Arrow
1046                    } else {
1047                        CursorStyle::PointingHand
1048                    })
1049                    .on_down(MouseButton::Left, move |_, cx| {
1050                        cx.dispatch_action(ActivateItem(ix));
1051                    })
1052                    .on_click(MouseButton::Middle, {
1053                        let item = item.clone();
1054                        let pane = pane.clone();
1055                        move |_, cx: &mut EventContext| {
1056                            cx.dispatch_action(CloseItem {
1057                                item_id: item.id(),
1058                                pane: pane.clone(),
1059                            })
1060                        }
1061                    })
1062                    .on_up(MouseButton::Left, {
1063                        let pane = pane.clone();
1064                        move |_, cx: &mut EventContext| Pane::handle_dropped_item(&pane, ix, cx)
1065                    })
1066                    .as_draggable(
1067                        DraggedItem {
1068                            item,
1069                            pane: pane.clone(),
1070                        },
1071                        {
1072                            let theme = cx.global::<Settings>().theme.clone();
1073
1074                            let detail = detail.clone();
1075                            move |dragged_item, cx: &mut RenderContext<Workspace>| {
1076                                let tab_style = &theme.workspace.tab_bar.dragged_tab;
1077                                Self::render_tab(
1078                                    &dragged_item.item,
1079                                    dragged_item.pane.clone(),
1080                                    detail,
1081                                    false,
1082                                    None,
1083                                    &tab_style,
1084                                    cx,
1085                                )
1086                            }
1087                        },
1088                    )
1089                    .boxed()
1090                })
1091            }
1092
1093            // Use the inactive tab style along with the current pane's active status to decide how to render
1094            // the filler
1095            let filler_style = theme.workspace.tab_bar.tab_style(pane_active, false);
1096            row.add_child(
1097                MouseEventHandler::new::<Filler, _, _>(0, cx, |mouse_state, cx| {
1098                    let mut filler = Empty::new()
1099                        .contained()
1100                        .with_style(filler_style.container)
1101                        .with_border(filler_style.container.border);
1102
1103                    if let Some(overlay) = Self::tab_overlay_color(mouse_state.hovered, &theme, cx)
1104                    {
1105                        filler = filler.with_overlay_color(overlay);
1106                    }
1107
1108                    filler.boxed()
1109                })
1110                .flex(1., true)
1111                .named("filler"),
1112            );
1113
1114            row.boxed()
1115        })
1116        .on_up(MouseButton::Left, move |_, cx| {
1117            Pane::handle_dropped_item(&pane, filler_index, cx)
1118        })
1119    }
1120
1121    fn tab_details(&self, cx: &AppContext) -> Vec<usize> {
1122        let mut tab_details = (0..self.items.len()).map(|_| 0).collect::<Vec<_>>();
1123
1124        let mut tab_descriptions = HashMap::default();
1125        let mut done = false;
1126        while !done {
1127            done = true;
1128
1129            // Store item indices by their tab description.
1130            for (ix, (item, detail)) in self.items.iter().zip(&tab_details).enumerate() {
1131                if let Some(description) = item.tab_description(*detail, cx) {
1132                    if *detail == 0
1133                        || Some(&description) != item.tab_description(detail - 1, cx).as_ref()
1134                    {
1135                        tab_descriptions
1136                            .entry(description)
1137                            .or_insert(Vec::new())
1138                            .push(ix);
1139                    }
1140                }
1141            }
1142
1143            // If two or more items have the same tab description, increase their level
1144            // of detail and try again.
1145            for (_, item_ixs) in tab_descriptions.drain() {
1146                if item_ixs.len() > 1 {
1147                    done = false;
1148                    for ix in item_ixs {
1149                        tab_details[ix] += 1;
1150                    }
1151                }
1152            }
1153        }
1154
1155        tab_details
1156    }
1157
1158    fn render_tab<V: View>(
1159        item: &Box<dyn ItemHandle>,
1160        pane: WeakViewHandle<Pane>,
1161        detail: Option<usize>,
1162        hovered: bool,
1163        overlay: Option<Color>,
1164        tab_style: &theme::Tab,
1165        cx: &mut RenderContext<V>,
1166    ) -> ElementBox {
1167        let title = item.tab_content(detail, &tab_style, cx);
1168
1169        let mut tab = Flex::row()
1170            .with_child(
1171                Align::new({
1172                    let diameter = 7.0;
1173                    let icon_color = if item.has_conflict(cx) {
1174                        Some(tab_style.icon_conflict)
1175                    } else if item.is_dirty(cx) {
1176                        Some(tab_style.icon_dirty)
1177                    } else {
1178                        None
1179                    };
1180
1181                    ConstrainedBox::new(
1182                        Canvas::new(move |bounds, _, cx| {
1183                            if let Some(color) = icon_color {
1184                                let square = RectF::new(bounds.origin(), vec2f(diameter, diameter));
1185                                cx.scene.push_quad(Quad {
1186                                    bounds: square,
1187                                    background: Some(color),
1188                                    border: Default::default(),
1189                                    corner_radius: diameter / 2.,
1190                                });
1191                            }
1192                        })
1193                        .boxed(),
1194                    )
1195                    .with_width(diameter)
1196                    .with_height(diameter)
1197                    .boxed()
1198                })
1199                .boxed(),
1200            )
1201            .with_child(
1202                Container::new(Align::new(title).boxed())
1203                    .with_style(ContainerStyle {
1204                        margin: Margin {
1205                            left: tab_style.spacing,
1206                            right: tab_style.spacing,
1207                            ..Default::default()
1208                        },
1209                        ..Default::default()
1210                    })
1211                    .boxed(),
1212            )
1213            .with_child(
1214                Align::new(
1215                    ConstrainedBox::new(if hovered {
1216                        let item_id = item.id();
1217                        enum TabCloseButton {}
1218                        let icon = Svg::new("icons/x_mark_thin_8.svg");
1219                        MouseEventHandler::new::<TabCloseButton, _, _>(
1220                            item_id,
1221                            cx,
1222                            |mouse_state, _| {
1223                                if mouse_state.hovered {
1224                                    icon.with_color(tab_style.icon_close_active).boxed()
1225                                } else {
1226                                    icon.with_color(tab_style.icon_close).boxed()
1227                                }
1228                            },
1229                        )
1230                        .with_padding(Padding::uniform(4.))
1231                        .with_cursor_style(CursorStyle::PointingHand)
1232                        .on_click(MouseButton::Left, {
1233                            let pane = pane.clone();
1234                            move |_, cx| {
1235                                cx.dispatch_action(CloseItem {
1236                                    item_id,
1237                                    pane: pane.clone(),
1238                                })
1239                            }
1240                        })
1241                        .on_click(MouseButton::Middle, |_, cx| cx.propogate_event())
1242                        .named("close-tab-icon")
1243                    } else {
1244                        Empty::new().boxed()
1245                    })
1246                    .with_width(tab_style.icon_width)
1247                    .boxed(),
1248                )
1249                .boxed(),
1250            )
1251            .contained()
1252            .with_style(tab_style.container);
1253
1254        if let Some(overlay) = overlay {
1255            tab = tab.with_overlay_color(overlay);
1256        }
1257
1258        tab.constrained().with_height(tab_style.height).boxed()
1259    }
1260
1261    fn handle_dropped_item(pane: &WeakViewHandle<Pane>, index: usize, cx: &mut EventContext) {
1262        if let Some((_, dragged_item)) = cx
1263            .global::<DragAndDrop<Workspace>>()
1264            .currently_dragged::<DraggedItem>(cx.window_id)
1265        {
1266            cx.dispatch_action(MoveItem {
1267                item_id: dragged_item.item.id(),
1268                from: dragged_item.pane.clone(),
1269                to: pane.clone(),
1270                destination_index: index,
1271            })
1272        } else {
1273            cx.propogate_event();
1274        }
1275    }
1276
1277    fn tab_overlay_color(
1278        hovered: bool,
1279        theme: &Theme,
1280        cx: &mut RenderContext<Self>,
1281    ) -> Option<Color> {
1282        if hovered
1283            && cx
1284                .global::<DragAndDrop<Workspace>>()
1285                .currently_dragged::<DraggedItem>(cx.window_id())
1286                .is_some()
1287        {
1288            Some(theme.workspace.tab_bar.drop_target_overlay_color)
1289        } else {
1290            None
1291        }
1292    }
1293}
1294
1295impl Entity for Pane {
1296    type Event = Event;
1297}
1298
1299impl View for Pane {
1300    fn ui_name() -> &'static str {
1301        "Pane"
1302    }
1303
1304    fn render(&mut self, cx: &mut RenderContext<Self>) -> ElementBox {
1305        enum SplitIcon {}
1306
1307        let this = cx.handle();
1308
1309        Stack::new()
1310            .with_child(
1311                EventHandler::new(if let Some(active_item) = self.active_item() {
1312                    Flex::column()
1313                        .with_child({
1314                            let mut tab_row = Flex::row()
1315                                .with_child(self.render_tab_bar(cx).flex(1., true).named("tabs"));
1316
1317                            if self.is_active {
1318                                tab_row.add_children([
1319                                    MouseEventHandler::new::<SplitIcon, _, _>(
1320                                        0,
1321                                        cx,
1322                                        |mouse_state, cx| {
1323                                            let theme =
1324                                                &cx.global::<Settings>().theme.workspace.tab_bar;
1325                                            let style =
1326                                                theme.pane_button.style_for(mouse_state, false);
1327                                            Svg::new("icons/plus_12.svg")
1328                                                .with_color(style.color)
1329                                                .constrained()
1330                                                .with_width(style.icon_width)
1331                                                .aligned()
1332                                                .contained()
1333                                                .with_style(style.container)
1334                                                .constrained()
1335                                                .with_width(style.button_width)
1336                                                .with_height(style.button_width)
1337                                                .aligned()
1338                                                .boxed()
1339                                        },
1340                                    )
1341                                    .with_cursor_style(CursorStyle::PointingHand)
1342                                    .on_down(MouseButton::Left, |e, cx| {
1343                                        cx.dispatch_action(DeployNewMenu {
1344                                            position: e.position,
1345                                        });
1346                                    })
1347                                    .boxed(),
1348                                    MouseEventHandler::new::<SplitIcon, _, _>(
1349                                        1,
1350                                        cx,
1351                                        |mouse_state, cx| {
1352                                            let theme =
1353                                                &cx.global::<Settings>().theme.workspace.tab_bar;
1354                                            let style =
1355                                                theme.pane_button.style_for(mouse_state, false);
1356                                            Svg::new("icons/split_12.svg")
1357                                                .with_color(style.color)
1358                                                .constrained()
1359                                                .with_width(style.icon_width)
1360                                                .aligned()
1361                                                .contained()
1362                                                .with_style(style.container)
1363                                                .constrained()
1364                                                .with_width(style.button_width)
1365                                                .with_height(style.button_width)
1366                                                .aligned()
1367                                                .boxed()
1368                                        },
1369                                    )
1370                                    .with_cursor_style(CursorStyle::PointingHand)
1371                                    .on_down(MouseButton::Left, |e, cx| {
1372                                        cx.dispatch_action(DeploySplitMenu {
1373                                            position: e.position,
1374                                        });
1375                                    })
1376                                    .boxed(),
1377                                ])
1378                            }
1379
1380                            tab_row
1381                                .constrained()
1382                                .with_height(cx.global::<Settings>().theme.workspace.tab_bar.height)
1383                                .named("tab bar")
1384                        })
1385                        .with_child(ChildView::new(&self.toolbar).boxed())
1386                        .with_child(ChildView::new(active_item).flex(1., true).boxed())
1387                        .boxed()
1388                } else {
1389                    enum EmptyPane {}
1390                    let theme = cx.global::<Settings>().theme.clone();
1391
1392                    MouseEventHandler::new::<EmptyPane, _, _>(0, cx, |_, _| {
1393                        Empty::new()
1394                            .contained()
1395                            .with_background_color(theme.workspace.background)
1396                            .boxed()
1397                    })
1398                    .on_down(MouseButton::Left, |_, cx| {
1399                        cx.focus_parent_view();
1400                    })
1401                    .boxed()
1402                })
1403                .on_navigate_mouse_down(move |direction, cx| {
1404                    let this = this.clone();
1405                    match direction {
1406                        NavigationDirection::Back => {
1407                            cx.dispatch_action(GoBack { pane: Some(this) })
1408                        }
1409                        NavigationDirection::Forward => {
1410                            cx.dispatch_action(GoForward { pane: Some(this) })
1411                        }
1412                    }
1413
1414                    true
1415                })
1416                .boxed(),
1417            )
1418            .with_child(ChildView::new(&self.context_menu).boxed())
1419            .named("pane")
1420    }
1421
1422    fn on_focus_in(&mut self, focused: AnyViewHandle, cx: &mut ViewContext<Self>) {
1423        if cx.is_self_focused() {
1424            if let Some(last_focused_view) = self
1425                .last_focused_view
1426                .as_ref()
1427                .and_then(|handle| handle.upgrade(cx))
1428            {
1429                cx.focus(last_focused_view);
1430            } else {
1431                self.focus_active_item(cx);
1432            }
1433        } else {
1434            self.last_focused_view = Some(focused.downgrade());
1435        }
1436        cx.emit(Event::Focused);
1437    }
1438}
1439
1440impl ItemNavHistory {
1441    pub fn push<D: 'static + Any>(&self, data: Option<D>, cx: &mut MutableAppContext) {
1442        self.history.borrow_mut().push(data, self.item.clone(), cx);
1443    }
1444
1445    pub fn pop_backward(&self, cx: &mut MutableAppContext) -> Option<NavigationEntry> {
1446        self.history.borrow_mut().pop(NavigationMode::GoingBack, cx)
1447    }
1448
1449    pub fn pop_forward(&self, cx: &mut MutableAppContext) -> Option<NavigationEntry> {
1450        self.history
1451            .borrow_mut()
1452            .pop(NavigationMode::GoingForward, cx)
1453    }
1454}
1455
1456impl NavHistory {
1457    fn set_mode(&mut self, mode: NavigationMode) {
1458        self.mode = mode;
1459    }
1460
1461    fn disable(&mut self) {
1462        self.mode = NavigationMode::Disabled;
1463    }
1464
1465    fn enable(&mut self) {
1466        self.mode = NavigationMode::Normal;
1467    }
1468
1469    fn pop(&mut self, mode: NavigationMode, cx: &mut MutableAppContext) -> Option<NavigationEntry> {
1470        let entry = match mode {
1471            NavigationMode::Normal | NavigationMode::Disabled | NavigationMode::ClosingItem => {
1472                return None
1473            }
1474            NavigationMode::GoingBack => &mut self.backward_stack,
1475            NavigationMode::GoingForward => &mut self.forward_stack,
1476            NavigationMode::ReopeningClosedItem => &mut self.closed_stack,
1477        }
1478        .pop_back();
1479        if entry.is_some() {
1480            self.did_update(cx);
1481        }
1482        entry
1483    }
1484
1485    fn push<D: 'static + Any>(
1486        &mut self,
1487        data: Option<D>,
1488        item: Rc<dyn WeakItemHandle>,
1489        cx: &mut MutableAppContext,
1490    ) {
1491        match self.mode {
1492            NavigationMode::Disabled => {}
1493            NavigationMode::Normal | NavigationMode::ReopeningClosedItem => {
1494                if self.backward_stack.len() >= MAX_NAVIGATION_HISTORY_LEN {
1495                    self.backward_stack.pop_front();
1496                }
1497                self.backward_stack.push_back(NavigationEntry {
1498                    item,
1499                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
1500                });
1501                self.forward_stack.clear();
1502            }
1503            NavigationMode::GoingBack => {
1504                if self.forward_stack.len() >= MAX_NAVIGATION_HISTORY_LEN {
1505                    self.forward_stack.pop_front();
1506                }
1507                self.forward_stack.push_back(NavigationEntry {
1508                    item,
1509                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
1510                });
1511            }
1512            NavigationMode::GoingForward => {
1513                if self.backward_stack.len() >= MAX_NAVIGATION_HISTORY_LEN {
1514                    self.backward_stack.pop_front();
1515                }
1516                self.backward_stack.push_back(NavigationEntry {
1517                    item,
1518                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
1519                });
1520            }
1521            NavigationMode::ClosingItem => {
1522                if self.closed_stack.len() >= MAX_NAVIGATION_HISTORY_LEN {
1523                    self.closed_stack.pop_front();
1524                }
1525                self.closed_stack.push_back(NavigationEntry {
1526                    item,
1527                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
1528                });
1529            }
1530        }
1531        self.did_update(cx);
1532    }
1533
1534    fn did_update(&self, cx: &mut MutableAppContext) {
1535        if let Some(pane) = self.pane.upgrade(cx) {
1536            cx.defer(move |cx| pane.update(cx, |pane, cx| pane.history_updated(cx)));
1537        }
1538    }
1539}
1540
1541#[cfg(test)]
1542mod tests {
1543    use gpui::TestAppContext;
1544    use project::FakeFs;
1545
1546    use crate::tests::TestItem;
1547
1548    use super::*;
1549
1550    #[gpui::test]
1551    async fn test_add_item_with_new_item(cx: &mut TestAppContext) {
1552        cx.foreground().forbid_parking();
1553        Settings::test_async(cx);
1554        let fs = FakeFs::new(cx.background());
1555
1556        let project = Project::test(fs, None, cx).await;
1557        let (_, workspace) = cx.add_window(|cx| Workspace::new(project, cx));
1558        let pane = workspace.read_with(cx, |workspace, _| workspace.active_pane().clone());
1559
1560        // 1. Add with a destination index
1561        //   a. Add before the active item
1562        set_labeled_items(&workspace, &pane, ["A", "B*", "C"], cx);
1563        workspace.update(cx, |workspace, cx| {
1564            Pane::add_item(
1565                workspace,
1566                &pane,
1567                Box::new(cx.add_view(|_| TestItem::new().with_label("D"))),
1568                false,
1569                false,
1570                Some(0),
1571                cx,
1572            );
1573        });
1574        assert_item_labels(&pane, ["D*", "A", "B", "C"], cx);
1575
1576        //   b. Add after the active item
1577        set_labeled_items(&workspace, &pane, ["A", "B*", "C"], cx);
1578        workspace.update(cx, |workspace, cx| {
1579            Pane::add_item(
1580                workspace,
1581                &pane,
1582                Box::new(cx.add_view(|_| TestItem::new().with_label("D"))),
1583                false,
1584                false,
1585                Some(2),
1586                cx,
1587            );
1588        });
1589        assert_item_labels(&pane, ["A", "B", "D*", "C"], cx);
1590
1591        //   c. Add at the end of the item list (including off the length)
1592        set_labeled_items(&workspace, &pane, ["A", "B*", "C"], cx);
1593        workspace.update(cx, |workspace, cx| {
1594            Pane::add_item(
1595                workspace,
1596                &pane,
1597                Box::new(cx.add_view(|_| TestItem::new().with_label("D"))),
1598                false,
1599                false,
1600                Some(5),
1601                cx,
1602            );
1603        });
1604        assert_item_labels(&pane, ["A", "B", "C", "D*"], cx);
1605
1606        // 2. Add without a destination index
1607        //   a. Add with active item at the start of the item list
1608        set_labeled_items(&workspace, &pane, ["A*", "B", "C"], cx);
1609        workspace.update(cx, |workspace, cx| {
1610            Pane::add_item(
1611                workspace,
1612                &pane,
1613                Box::new(cx.add_view(|_| TestItem::new().with_label("D"))),
1614                false,
1615                false,
1616                None,
1617                cx,
1618            );
1619        });
1620        set_labeled_items(&workspace, &pane, ["A", "D*", "B", "C"], cx);
1621
1622        //   b. Add with active item at the end of the item list
1623        set_labeled_items(&workspace, &pane, ["A", "B", "C*"], cx);
1624        workspace.update(cx, |workspace, cx| {
1625            Pane::add_item(
1626                workspace,
1627                &pane,
1628                Box::new(cx.add_view(|_| TestItem::new().with_label("D"))),
1629                false,
1630                false,
1631                None,
1632                cx,
1633            );
1634        });
1635        assert_item_labels(&pane, ["A", "B", "C", "D*"], cx);
1636    }
1637
1638    #[gpui::test]
1639    async fn test_add_item_with_existing_item(cx: &mut TestAppContext) {
1640        cx.foreground().forbid_parking();
1641        Settings::test_async(cx);
1642        let fs = FakeFs::new(cx.background());
1643
1644        let project = Project::test(fs, None, cx).await;
1645        let (_, workspace) = cx.add_window(|cx| Workspace::new(project, cx));
1646        let pane = workspace.read_with(cx, |workspace, _| workspace.active_pane().clone());
1647
1648        // 1. Add with a destination index
1649        //   1a. Add before the active item
1650        let [_, _, _, d] = set_labeled_items(&workspace, &pane, ["A", "B*", "C", "D"], cx);
1651        workspace.update(cx, |workspace, cx| {
1652            Pane::add_item(workspace, &pane, d, false, false, Some(0), cx);
1653        });
1654        assert_item_labels(&pane, ["D*", "A", "B", "C"], cx);
1655
1656        //   1b. Add after the active item
1657        let [_, _, _, d] = set_labeled_items(&workspace, &pane, ["A", "B*", "C", "D"], cx);
1658        workspace.update(cx, |workspace, cx| {
1659            Pane::add_item(workspace, &pane, d, false, false, Some(2), cx);
1660        });
1661        assert_item_labels(&pane, ["A", "B", "D*", "C"], cx);
1662
1663        //   1c. Add at the end of the item list (including off the length)
1664        let [a, _, _, _] = set_labeled_items(&workspace, &pane, ["A", "B*", "C", "D"], cx);
1665        workspace.update(cx, |workspace, cx| {
1666            Pane::add_item(workspace, &pane, a, false, false, Some(5), cx);
1667        });
1668        assert_item_labels(&pane, ["B", "C", "D", "A*"], cx);
1669
1670        //   1d. Add same item to active index
1671        let [_, b, _] = set_labeled_items(&workspace, &pane, ["A", "B*", "C"], cx);
1672        workspace.update(cx, |workspace, cx| {
1673            Pane::add_item(workspace, &pane, b, false, false, Some(1), cx);
1674        });
1675        assert_item_labels(&pane, ["A", "B*", "C"], cx);
1676
1677        //   1e. Add item to index after same item in last position
1678        let [_, _, c] = set_labeled_items(&workspace, &pane, ["A", "B*", "C"], cx);
1679        workspace.update(cx, |workspace, cx| {
1680            Pane::add_item(workspace, &pane, c, false, false, Some(2), cx);
1681        });
1682        assert_item_labels(&pane, ["A", "B", "C*"], cx);
1683
1684        // 2. Add without a destination index
1685        //   2a. Add with active item at the start of the item list
1686        let [_, _, _, d] = set_labeled_items(&workspace, &pane, ["A*", "B", "C", "D"], cx);
1687        workspace.update(cx, |workspace, cx| {
1688            Pane::add_item(workspace, &pane, d, false, false, None, cx);
1689        });
1690        assert_item_labels(&pane, ["A", "D*", "B", "C"], cx);
1691
1692        //   2b. Add with active item at the end of the item list
1693        let [a, _, _, _] = set_labeled_items(&workspace, &pane, ["A", "B", "C", "D*"], cx);
1694        workspace.update(cx, |workspace, cx| {
1695            Pane::add_item(workspace, &pane, a, false, false, None, cx);
1696        });
1697        assert_item_labels(&pane, ["B", "C", "D", "A*"], cx);
1698
1699        //   2c. Add active item to active item at end of list
1700        let [_, _, c] = set_labeled_items(&workspace, &pane, ["A", "B", "C*"], cx);
1701        workspace.update(cx, |workspace, cx| {
1702            Pane::add_item(workspace, &pane, c, false, false, None, cx);
1703        });
1704        assert_item_labels(&pane, ["A", "B", "C*"], cx);
1705
1706        //   2d. Add active item to active item at start of list
1707        let [a, _, _] = set_labeled_items(&workspace, &pane, ["A*", "B", "C"], cx);
1708        workspace.update(cx, |workspace, cx| {
1709            Pane::add_item(workspace, &pane, a, false, false, None, cx);
1710        });
1711        assert_item_labels(&pane, ["A*", "B", "C"], cx);
1712    }
1713
1714    fn set_labeled_items<const COUNT: usize>(
1715        workspace: &ViewHandle<Workspace>,
1716        pane: &ViewHandle<Pane>,
1717        labels: [&str; COUNT],
1718        cx: &mut TestAppContext,
1719    ) -> [Box<ViewHandle<TestItem>>; COUNT] {
1720        pane.update(cx, |pane, _| {
1721            pane.items.clear();
1722        });
1723
1724        workspace.update(cx, |workspace, cx| {
1725            let mut active_item_index = 0;
1726
1727            let mut index = 0;
1728            let items = labels.map(|mut label| {
1729                if label.ends_with("*") {
1730                    label = label.trim_end_matches("*");
1731                    active_item_index = index;
1732                }
1733
1734                let labeled_item = Box::new(cx.add_view(|_| TestItem::new().with_label(label)));
1735                Pane::add_item(
1736                    workspace,
1737                    pane,
1738                    labeled_item.clone(),
1739                    false,
1740                    false,
1741                    None,
1742                    cx,
1743                );
1744                index += 1;
1745                labeled_item
1746            });
1747
1748            pane.update(cx, |pane, cx| {
1749                pane.activate_item(active_item_index, false, false, cx)
1750            });
1751
1752            items
1753        })
1754    }
1755
1756    // Assert the item label, with the active item label suffixed with a '*'
1757    fn assert_item_labels<const COUNT: usize>(
1758        pane: &ViewHandle<Pane>,
1759        expected_states: [&str; COUNT],
1760        cx: &mut TestAppContext,
1761    ) {
1762        pane.read_with(cx, |pane, cx| {
1763            let actual_states = pane
1764                .items
1765                .iter()
1766                .enumerate()
1767                .map(|(ix, item)| {
1768                    let mut state = item
1769                        .to_any()
1770                        .downcast::<TestItem>()
1771                        .unwrap()
1772                        .read(cx)
1773                        .label
1774                        .clone();
1775                    if ix == pane.active_item_index {
1776                        state.push('*');
1777                    }
1778                    state
1779                })
1780                .collect::<Vec<_>>();
1781
1782            assert_eq!(
1783                actual_states, expected_states,
1784                "pane items do not match expectation"
1785            );
1786        })
1787    }
1788}