pane.rs

   1use super::{ItemHandle, SplitDirection};
   2use crate::{toolbar::Toolbar, Item, WeakItemHandle, Workspace};
   3use anyhow::Result;
   4use collections::{HashMap, HashSet, VecDeque};
   5use context_menu::{ContextMenu, ContextMenuItem};
   6use futures::StreamExt;
   7use gpui::{
   8    actions,
   9    elements::*,
  10    geometry::{
  11        rect::RectF,
  12        vector::{vec2f, Vector2F},
  13    },
  14    impl_actions, impl_internal_actions,
  15    platform::{CursorStyle, NavigationDirection},
  16    AppContext, AsyncAppContext, Entity, ModelHandle, MutableAppContext, PromptLevel, Quad,
  17    RenderContext, Task, View, ViewContext, ViewHandle, WeakViewHandle,
  18};
  19use project::{Project, ProjectEntryId, ProjectPath};
  20use serde::Deserialize;
  21use settings::{Autosave, Settings};
  22use std::{any::Any, cell::RefCell, mem, path::Path, rc::Rc};
  23use util::ResultExt;
  24
  25#[derive(Clone, Deserialize, PartialEq)]
  26pub struct ActivateItem(pub usize);
  27
  28actions!(
  29    pane,
  30    [
  31        ActivatePrevItem,
  32        ActivateNextItem,
  33        ActivateLastItem,
  34        CloseActiveItem,
  35        CloseInactiveItems,
  36        ReopenClosedItem,
  37        SplitLeft,
  38        SplitUp,
  39        SplitRight,
  40        SplitDown,
  41    ]
  42);
  43
  44#[derive(Clone, PartialEq)]
  45pub struct CloseItem {
  46    pub item_id: usize,
  47    pub pane: WeakViewHandle<Pane>,
  48}
  49
  50#[derive(Clone, Deserialize, PartialEq)]
  51pub struct GoBack {
  52    #[serde(skip_deserializing)]
  53    pub pane: Option<WeakViewHandle<Pane>>,
  54}
  55
  56#[derive(Clone, Deserialize, PartialEq)]
  57pub struct GoForward {
  58    #[serde(skip_deserializing)]
  59    pub pane: Option<WeakViewHandle<Pane>>,
  60}
  61
  62#[derive(Clone, PartialEq)]
  63pub struct DeploySplitMenu {
  64    position: Vector2F,
  65}
  66
  67impl_actions!(pane, [GoBack, GoForward, ActivateItem]);
  68impl_internal_actions!(pane, [CloseItem, DeploySplitMenu]);
  69
  70const MAX_NAVIGATION_HISTORY_LEN: usize = 1024;
  71
  72pub fn init(cx: &mut MutableAppContext) {
  73    cx.add_action(|pane: &mut Pane, action: &ActivateItem, cx| {
  74        pane.activate_item(action.0, true, true, false, cx);
  75    });
  76    cx.add_action(|pane: &mut Pane, _: &ActivateLastItem, cx| {
  77        pane.activate_item(pane.items.len() - 1, true, true, false, cx);
  78    });
  79    cx.add_action(|pane: &mut Pane, _: &ActivatePrevItem, cx| {
  80        pane.activate_prev_item(cx);
  81    });
  82    cx.add_action(|pane: &mut Pane, _: &ActivateNextItem, cx| {
  83        pane.activate_next_item(cx);
  84    });
  85    cx.add_async_action(Pane::close_active_item);
  86    cx.add_async_action(Pane::close_inactive_items);
  87    cx.add_async_action(|workspace: &mut Workspace, action: &CloseItem, cx| {
  88        let pane = action.pane.upgrade(cx)?;
  89        let task = Pane::close_item(workspace, pane, action.item_id, cx);
  90        Some(cx.foreground().spawn(async move {
  91            task.await?;
  92            Ok(())
  93        }))
  94    });
  95    cx.add_action(|pane: &mut Pane, _: &SplitLeft, cx| pane.split(SplitDirection::Left, cx));
  96    cx.add_action(|pane: &mut Pane, _: &SplitUp, cx| pane.split(SplitDirection::Up, cx));
  97    cx.add_action(|pane: &mut Pane, _: &SplitRight, cx| pane.split(SplitDirection::Right, cx));
  98    cx.add_action(|pane: &mut Pane, _: &SplitDown, cx| pane.split(SplitDirection::Down, cx));
  99    cx.add_action(Pane::deploy_split_menu);
 100    cx.add_action(|workspace: &mut Workspace, _: &ReopenClosedItem, cx| {
 101        Pane::reopen_closed_item(workspace, cx).detach();
 102    });
 103    cx.add_action(|workspace: &mut Workspace, action: &GoBack, cx| {
 104        Pane::go_back(
 105            workspace,
 106            action
 107                .pane
 108                .as_ref()
 109                .and_then(|weak_handle| weak_handle.upgrade(cx)),
 110            cx,
 111        )
 112        .detach();
 113    });
 114    cx.add_action(|workspace: &mut Workspace, action: &GoForward, cx| {
 115        Pane::go_forward(
 116            workspace,
 117            action
 118                .pane
 119                .as_ref()
 120                .and_then(|weak_handle| weak_handle.upgrade(cx)),
 121            cx,
 122        )
 123        .detach();
 124    });
 125}
 126
 127pub enum Event {
 128    Activate,
 129    ActivateItem { local: bool },
 130    Remove,
 131    RemoveItem,
 132    Split(SplitDirection),
 133    ChangeItemTitle,
 134}
 135
 136pub struct Pane {
 137    items: Vec<Box<dyn ItemHandle>>,
 138    active_item_index: usize,
 139    autoscroll: bool,
 140    nav_history: Rc<RefCell<NavHistory>>,
 141    toolbar: ViewHandle<Toolbar>,
 142    split_menu: ViewHandle<ContextMenu>,
 143}
 144
 145pub struct ItemNavHistory {
 146    history: Rc<RefCell<NavHistory>>,
 147    item: Rc<dyn WeakItemHandle>,
 148}
 149
 150struct NavHistory {
 151    mode: NavigationMode,
 152    backward_stack: VecDeque<NavigationEntry>,
 153    forward_stack: VecDeque<NavigationEntry>,
 154    closed_stack: VecDeque<NavigationEntry>,
 155    paths_by_item: HashMap<usize, ProjectPath>,
 156    pane: WeakViewHandle<Pane>,
 157}
 158
 159#[derive(Copy, Clone)]
 160enum NavigationMode {
 161    Normal,
 162    GoingBack,
 163    GoingForward,
 164    ClosingItem,
 165    ReopeningClosedItem,
 166    Disabled,
 167}
 168
 169impl Default for NavigationMode {
 170    fn default() -> Self {
 171        Self::Normal
 172    }
 173}
 174
 175pub struct NavigationEntry {
 176    pub item: Rc<dyn WeakItemHandle>,
 177    pub data: Option<Box<dyn Any>>,
 178}
 179
 180impl Pane {
 181    pub fn new(cx: &mut ViewContext<Self>) -> Self {
 182        let handle = cx.weak_handle();
 183        let split_menu = cx.add_view(|cx| ContextMenu::new(cx));
 184        Self {
 185            items: Vec::new(),
 186            active_item_index: 0,
 187            autoscroll: false,
 188            nav_history: Rc::new(RefCell::new(NavHistory {
 189                mode: NavigationMode::Normal,
 190                backward_stack: Default::default(),
 191                forward_stack: Default::default(),
 192                closed_stack: Default::default(),
 193                paths_by_item: Default::default(),
 194                pane: handle.clone(),
 195            })),
 196            toolbar: cx.add_view(|_| Toolbar::new(handle)),
 197            split_menu,
 198        }
 199    }
 200
 201    pub fn nav_history_for_item<T: Item>(&self, item: &ViewHandle<T>) -> ItemNavHistory {
 202        ItemNavHistory {
 203            history: self.nav_history.clone(),
 204            item: Rc::new(item.downgrade()),
 205        }
 206    }
 207
 208    pub fn activate(&self, cx: &mut ViewContext<Self>) {
 209        cx.emit(Event::Activate);
 210    }
 211
 212    pub fn go_back(
 213        workspace: &mut Workspace,
 214        pane: Option<ViewHandle<Pane>>,
 215        cx: &mut ViewContext<Workspace>,
 216    ) -> Task<()> {
 217        Self::navigate_history(
 218            workspace,
 219            pane.unwrap_or_else(|| workspace.active_pane().clone()),
 220            NavigationMode::GoingBack,
 221            cx,
 222        )
 223    }
 224
 225    pub fn go_forward(
 226        workspace: &mut Workspace,
 227        pane: Option<ViewHandle<Pane>>,
 228        cx: &mut ViewContext<Workspace>,
 229    ) -> Task<()> {
 230        Self::navigate_history(
 231            workspace,
 232            pane.unwrap_or_else(|| workspace.active_pane().clone()),
 233            NavigationMode::GoingForward,
 234            cx,
 235        )
 236    }
 237
 238    pub fn reopen_closed_item(
 239        workspace: &mut Workspace,
 240        cx: &mut ViewContext<Workspace>,
 241    ) -> Task<()> {
 242        Self::navigate_history(
 243            workspace,
 244            workspace.active_pane().clone(),
 245            NavigationMode::ReopeningClosedItem,
 246            cx,
 247        )
 248    }
 249
 250    pub fn disable_history(&mut self) {
 251        self.nav_history.borrow_mut().disable();
 252    }
 253
 254    pub fn enable_history(&mut self) {
 255        self.nav_history.borrow_mut().enable();
 256    }
 257
 258    pub fn can_navigate_backward(&self) -> bool {
 259        !self.nav_history.borrow().backward_stack.is_empty()
 260    }
 261
 262    pub fn can_navigate_forward(&self) -> bool {
 263        !self.nav_history.borrow().forward_stack.is_empty()
 264    }
 265
 266    fn history_updated(&mut self, cx: &mut ViewContext<Self>) {
 267        self.toolbar.update(cx, |_, cx| cx.notify());
 268    }
 269
 270    fn navigate_history(
 271        workspace: &mut Workspace,
 272        pane: ViewHandle<Pane>,
 273        mode: NavigationMode,
 274        cx: &mut ViewContext<Workspace>,
 275    ) -> Task<()> {
 276        workspace.activate_pane(pane.clone(), cx);
 277
 278        let to_load = pane.update(cx, |pane, cx| {
 279            loop {
 280                // Retrieve the weak item handle from the history.
 281                let entry = pane.nav_history.borrow_mut().pop(mode, cx)?;
 282
 283                // If the item is still present in this pane, then activate it.
 284                if let Some(index) = entry
 285                    .item
 286                    .upgrade(cx)
 287                    .and_then(|v| pane.index_for_item(v.as_ref()))
 288                {
 289                    let prev_active_item_index = pane.active_item_index;
 290                    pane.nav_history.borrow_mut().set_mode(mode);
 291                    pane.activate_item(index, true, true, false, cx);
 292                    pane.nav_history
 293                        .borrow_mut()
 294                        .set_mode(NavigationMode::Normal);
 295
 296                    let mut navigated = prev_active_item_index != pane.active_item_index;
 297                    if let Some(data) = entry.data {
 298                        navigated |= pane.active_item()?.navigate(data, cx);
 299                    }
 300
 301                    if navigated {
 302                        break None;
 303                    }
 304                }
 305                // If the item is no longer present in this pane, then retrieve its
 306                // project path in order to reopen it.
 307                else {
 308                    break pane
 309                        .nav_history
 310                        .borrow()
 311                        .paths_by_item
 312                        .get(&entry.item.id())
 313                        .cloned()
 314                        .map(|project_path| (project_path, entry));
 315                }
 316            }
 317        });
 318
 319        if let Some((project_path, entry)) = to_load {
 320            // If the item was no longer present, then load it again from its previous path.
 321            let pane = pane.downgrade();
 322            let task = workspace.load_path(project_path, cx);
 323            cx.spawn(|workspace, mut cx| async move {
 324                let task = task.await;
 325                if let Some(pane) = pane.upgrade(&cx) {
 326                    let mut navigated = false;
 327                    if let Some((project_entry_id, build_item)) = task.log_err() {
 328                        let prev_active_item_id = pane.update(&mut cx, |pane, _| {
 329                            pane.nav_history.borrow_mut().set_mode(mode);
 330                            pane.active_item().map(|p| p.id())
 331                        });
 332
 333                        let item = workspace.update(&mut cx, |workspace, cx| {
 334                            Self::open_item(
 335                                workspace,
 336                                pane.clone(),
 337                                project_entry_id,
 338                                true,
 339                                cx,
 340                                build_item,
 341                            )
 342                        });
 343
 344                        pane.update(&mut cx, |pane, cx| {
 345                            navigated |= Some(item.id()) != prev_active_item_id;
 346                            pane.nav_history
 347                                .borrow_mut()
 348                                .set_mode(NavigationMode::Normal);
 349                            if let Some(data) = entry.data {
 350                                navigated |= item.navigate(data, cx);
 351                            }
 352                        });
 353                    }
 354
 355                    if !navigated {
 356                        workspace
 357                            .update(&mut cx, |workspace, cx| {
 358                                Self::navigate_history(workspace, pane, mode, cx)
 359                            })
 360                            .await;
 361                    }
 362                }
 363            })
 364        } else {
 365            Task::ready(())
 366        }
 367    }
 368
 369    pub(crate) fn open_item(
 370        workspace: &mut Workspace,
 371        pane: ViewHandle<Pane>,
 372        project_entry_id: ProjectEntryId,
 373        focus_item: bool,
 374        cx: &mut ViewContext<Workspace>,
 375        build_item: impl FnOnce(&mut MutableAppContext) -> Box<dyn ItemHandle>,
 376    ) -> Box<dyn ItemHandle> {
 377        let existing_item = pane.update(cx, |pane, cx| {
 378            for (ix, item) in pane.items.iter().enumerate() {
 379                if item.project_path(cx).is_some()
 380                    && item.project_entry_ids(cx).as_slice() == &[project_entry_id]
 381                {
 382                    let item = item.boxed_clone();
 383                    pane.activate_item(ix, true, focus_item, true, cx);
 384                    return Some(item);
 385                }
 386            }
 387            None
 388        });
 389        if let Some(existing_item) = existing_item {
 390            existing_item
 391        } else {
 392            let item = build_item(cx);
 393            Self::add_item(workspace, pane, item.boxed_clone(), true, focus_item, cx);
 394            item
 395        }
 396    }
 397
 398    pub(crate) fn add_item(
 399        workspace: &mut Workspace,
 400        pane: ViewHandle<Pane>,
 401        item: Box<dyn ItemHandle>,
 402        activate_pane: bool,
 403        focus_item: bool,
 404        cx: &mut ViewContext<Workspace>,
 405    ) {
 406        // Prevent adding the same item to the pane more than once.
 407        // If there is already an active item, reorder the desired item to be after it
 408        // and activate it.
 409        if let Some(item_ix) = pane.read(cx).items.iter().position(|i| i.id() == item.id()) {
 410            pane.update(cx, |pane, cx| {
 411                pane.activate_item(item_ix, activate_pane, focus_item, true, cx)
 412            });
 413            return;
 414        }
 415
 416        item.added_to_pane(workspace, pane.clone(), cx);
 417        pane.update(cx, |pane, cx| {
 418            // If there is already an active item, then insert the new item
 419            // right after it. Otherwise, adjust the `active_item_index` field
 420            // before activating the new item, so that in the `activate_item`
 421            // method, we can detect that the active item is changing.
 422            let item_ix;
 423            if pane.active_item_index < pane.items.len() {
 424                item_ix = pane.active_item_index + 1
 425            } else {
 426                item_ix = pane.items.len();
 427                pane.active_item_index = usize::MAX;
 428            };
 429
 430            pane.items.insert(item_ix, item);
 431            pane.activate_item(item_ix, activate_pane, focus_item, false, cx);
 432            cx.notify();
 433        });
 434    }
 435
 436    pub fn items(&self) -> impl Iterator<Item = &Box<dyn ItemHandle>> {
 437        self.items.iter()
 438    }
 439
 440    pub fn items_of_type<'a, T: View>(&'a self) -> impl 'a + Iterator<Item = ViewHandle<T>> {
 441        self.items
 442            .iter()
 443            .filter_map(|item| item.to_any().downcast())
 444    }
 445
 446    pub fn active_item(&self) -> Option<Box<dyn ItemHandle>> {
 447        self.items.get(self.active_item_index).cloned()
 448    }
 449
 450    pub fn item_for_entry(
 451        &self,
 452        entry_id: ProjectEntryId,
 453        cx: &AppContext,
 454    ) -> Option<Box<dyn ItemHandle>> {
 455        self.items.iter().find_map(|item| {
 456            if item.is_singleton(cx) && item.project_entry_ids(cx).as_slice() == &[entry_id] {
 457                Some(item.boxed_clone())
 458            } else {
 459                None
 460            }
 461        })
 462    }
 463
 464    pub fn index_for_item(&self, item: &dyn ItemHandle) -> Option<usize> {
 465        self.items.iter().position(|i| i.id() == item.id())
 466    }
 467
 468    pub fn activate_item(
 469        &mut self,
 470        mut index: usize,
 471        activate_pane: bool,
 472        focus_item: bool,
 473        move_after_current_active: bool,
 474        cx: &mut ViewContext<Self>,
 475    ) {
 476        use NavigationMode::{GoingBack, GoingForward};
 477        if index < self.items.len() {
 478            if move_after_current_active {
 479                // If there is already an active item, reorder the desired item to be after it
 480                // and activate it.
 481                if self.active_item_index != index && self.active_item_index < self.items.len() {
 482                    let pane_to_activate = self.items.remove(index);
 483                    if self.active_item_index < index {
 484                        index = self.active_item_index + 1;
 485                    } else if self.active_item_index < self.items.len() + 1 {
 486                        index = self.active_item_index;
 487                        // Index is less than active_item_index. Reordering will decrement the
 488                        // active_item_index, so adjust it accordingly
 489                        self.active_item_index = index - 1;
 490                    }
 491                    self.items.insert(index, pane_to_activate);
 492                }
 493            }
 494
 495            let prev_active_item_ix = mem::replace(&mut self.active_item_index, index);
 496            if prev_active_item_ix != self.active_item_index
 497                || matches!(self.nav_history.borrow().mode, GoingBack | GoingForward)
 498            {
 499                if let Some(prev_item) = self.items.get(prev_active_item_ix) {
 500                    prev_item.deactivated(cx);
 501                }
 502                cx.emit(Event::ActivateItem {
 503                    local: activate_pane,
 504                });
 505            }
 506            self.update_toolbar(cx);
 507            if focus_item {
 508                self.focus_active_item(cx);
 509            }
 510            if activate_pane {
 511                self.activate(cx);
 512            }
 513            self.autoscroll = true;
 514            cx.notify();
 515        }
 516    }
 517
 518    pub fn activate_prev_item(&mut self, cx: &mut ViewContext<Self>) {
 519        let mut index = self.active_item_index;
 520        if index > 0 {
 521            index -= 1;
 522        } else if self.items.len() > 0 {
 523            index = self.items.len() - 1;
 524        }
 525        self.activate_item(index, true, true, false, cx);
 526    }
 527
 528    pub fn activate_next_item(&mut self, cx: &mut ViewContext<Self>) {
 529        let mut index = self.active_item_index;
 530        if index + 1 < self.items.len() {
 531            index += 1;
 532        } else {
 533            index = 0;
 534        }
 535        self.activate_item(index, true, true, false, cx);
 536    }
 537
 538    pub fn close_active_item(
 539        workspace: &mut Workspace,
 540        _: &CloseActiveItem,
 541        cx: &mut ViewContext<Workspace>,
 542    ) -> Option<Task<Result<()>>> {
 543        let pane_handle = workspace.active_pane().clone();
 544        let pane = pane_handle.read(cx);
 545        if pane.items.is_empty() {
 546            None
 547        } else {
 548            let item_id_to_close = pane.items[pane.active_item_index].id();
 549            let task = Self::close_items(workspace, pane_handle, cx, move |item_id| {
 550                item_id == item_id_to_close
 551            });
 552            Some(cx.foreground().spawn(async move {
 553                task.await?;
 554                Ok(())
 555            }))
 556        }
 557    }
 558
 559    pub fn close_inactive_items(
 560        workspace: &mut Workspace,
 561        _: &CloseInactiveItems,
 562        cx: &mut ViewContext<Workspace>,
 563    ) -> Option<Task<Result<()>>> {
 564        let pane_handle = workspace.active_pane().clone();
 565        let pane = pane_handle.read(cx);
 566        if pane.items.is_empty() {
 567            None
 568        } else {
 569            let active_item_id = pane.items[pane.active_item_index].id();
 570            let task =
 571                Self::close_items(workspace, pane_handle, cx, move |id| id != active_item_id);
 572            Some(cx.foreground().spawn(async move {
 573                task.await?;
 574                Ok(())
 575            }))
 576        }
 577    }
 578
 579    pub fn close_item(
 580        workspace: &mut Workspace,
 581        pane: ViewHandle<Pane>,
 582        item_id_to_close: usize,
 583        cx: &mut ViewContext<Workspace>,
 584    ) -> Task<Result<bool>> {
 585        Self::close_items(workspace, pane, cx, move |view_id| {
 586            view_id == item_id_to_close
 587        })
 588    }
 589
 590    pub fn close_items(
 591        workspace: &mut Workspace,
 592        pane: ViewHandle<Pane>,
 593        cx: &mut ViewContext<Workspace>,
 594        should_close: impl 'static + Fn(usize) -> bool,
 595    ) -> Task<Result<bool>> {
 596        let project = workspace.project().clone();
 597
 598        // Find the items to close.
 599        let mut items_to_close = Vec::new();
 600        for item in &pane.read(cx).items {
 601            if should_close(item.id()) {
 602                items_to_close.push(item.boxed_clone());
 603            }
 604        }
 605
 606        // If a buffer is open both in a singleton editor and in a multibuffer, make sure
 607        // to focus the singleton buffer when prompting to save that buffer, as opposed
 608        // to focusing the multibuffer, because this gives the user a more clear idea
 609        // of what content they would be saving.
 610        items_to_close.sort_by_key(|item| !item.is_singleton(cx));
 611
 612        cx.spawn(|workspace, mut cx| async move {
 613            let mut saved_project_entry_ids = HashSet::default();
 614            for item in items_to_close.clone() {
 615                // Find the item's current index and its set of project entries. Avoid
 616                // storing these in advance, in case they have changed since this task
 617                // was started.
 618                let (item_ix, mut project_entry_ids) = pane.read_with(&cx, |pane, cx| {
 619                    (pane.index_for_item(&*item), item.project_entry_ids(cx))
 620                });
 621                let item_ix = if let Some(ix) = item_ix {
 622                    ix
 623                } else {
 624                    continue;
 625                };
 626
 627                // If an item hasn't yet been associated with a project entry, then always
 628                // prompt to save it before closing it. Otherwise, check if the item has
 629                // any project entries that are not open anywhere else in the workspace,
 630                // AND that the user has not already been prompted to save. If there are
 631                // any such project entries, prompt the user to save this item.
 632                let should_save = if project_entry_ids.is_empty() {
 633                    true
 634                } else {
 635                    workspace.read_with(&cx, |workspace, cx| {
 636                        for item in workspace.items(cx) {
 637                            if !items_to_close
 638                                .iter()
 639                                .any(|item_to_close| item_to_close.id() == item.id())
 640                            {
 641                                let other_project_entry_ids = item.project_entry_ids(cx);
 642                                project_entry_ids
 643                                    .retain(|id| !other_project_entry_ids.contains(&id));
 644                            }
 645                        }
 646                    });
 647                    project_entry_ids
 648                        .iter()
 649                        .any(|id| saved_project_entry_ids.insert(*id))
 650                };
 651
 652                if should_save {
 653                    if !Self::save_item(project.clone(), &pane, item_ix, &item, true, &mut cx)
 654                        .await?
 655                    {
 656                        break;
 657                    }
 658                }
 659
 660                // Remove the item from the pane.
 661                pane.update(&mut cx, |pane, cx| {
 662                    if let Some(item_ix) = pane.items.iter().position(|i| i.id() == item.id()) {
 663                        if item_ix == pane.active_item_index {
 664                            // Activate the previous item if possible.
 665                            // This returns the user to the previously opened tab if they closed
 666                            // a ne item they just navigated to.
 667                            if item_ix > 0 {
 668                                pane.activate_prev_item(cx);
 669                            } else if item_ix + 1 < pane.items.len() {
 670                                pane.activate_next_item(cx);
 671                            }
 672                        }
 673
 674                        let item = pane.items.remove(item_ix);
 675                        cx.emit(Event::RemoveItem);
 676                        if pane.items.is_empty() {
 677                            item.deactivated(cx);
 678                            pane.update_toolbar(cx);
 679                            cx.emit(Event::Remove);
 680                        }
 681
 682                        if item_ix < pane.active_item_index {
 683                            pane.active_item_index -= 1;
 684                        }
 685
 686                        pane.nav_history
 687                            .borrow_mut()
 688                            .set_mode(NavigationMode::ClosingItem);
 689                        item.deactivated(cx);
 690                        pane.nav_history
 691                            .borrow_mut()
 692                            .set_mode(NavigationMode::Normal);
 693
 694                        if let Some(path) = item.project_path(cx) {
 695                            pane.nav_history
 696                                .borrow_mut()
 697                                .paths_by_item
 698                                .insert(item.id(), path);
 699                        } else {
 700                            pane.nav_history
 701                                .borrow_mut()
 702                                .paths_by_item
 703                                .remove(&item.id());
 704                        }
 705                    }
 706                });
 707            }
 708
 709            pane.update(&mut cx, |_, cx| cx.notify());
 710            Ok(true)
 711        })
 712    }
 713
 714    pub async fn save_item(
 715        project: ModelHandle<Project>,
 716        pane: &ViewHandle<Pane>,
 717        item_ix: usize,
 718        item: &Box<dyn ItemHandle>,
 719        should_prompt_for_save: bool,
 720        cx: &mut AsyncAppContext,
 721    ) -> Result<bool> {
 722        const CONFLICT_MESSAGE: &'static str =
 723            "This file has changed on disk since you started editing it. Do you want to overwrite it?";
 724        const DIRTY_MESSAGE: &'static str =
 725            "This file contains unsaved edits. Do you want to save it?";
 726
 727        let (has_conflict, is_dirty, can_save, is_singleton) = cx.read(|cx| {
 728            (
 729                item.has_conflict(cx),
 730                item.is_dirty(cx),
 731                item.can_save(cx),
 732                item.is_singleton(cx),
 733            )
 734        });
 735
 736        if has_conflict && can_save {
 737            let mut answer = pane.update(cx, |pane, cx| {
 738                pane.activate_item(item_ix, true, true, false, cx);
 739                cx.prompt(
 740                    PromptLevel::Warning,
 741                    CONFLICT_MESSAGE,
 742                    &["Overwrite", "Discard", "Cancel"],
 743                )
 744            });
 745            match answer.next().await {
 746                Some(0) => cx.update(|cx| item.save(project, cx)).await?,
 747                Some(1) => cx.update(|cx| item.reload(project, cx)).await?,
 748                _ => return Ok(false),
 749            }
 750        } else if is_dirty && (can_save || is_singleton) {
 751            let will_autosave = cx.read(|cx| {
 752                matches!(
 753                    cx.global::<Settings>().autosave,
 754                    Autosave::OnFocusChange | Autosave::OnWindowChange
 755                ) && Self::can_autosave_item(item.as_ref(), cx)
 756            });
 757            let should_save = if should_prompt_for_save && !will_autosave {
 758                let mut answer = pane.update(cx, |pane, cx| {
 759                    pane.activate_item(item_ix, true, true, false, cx);
 760                    cx.prompt(
 761                        PromptLevel::Warning,
 762                        DIRTY_MESSAGE,
 763                        &["Save", "Don't Save", "Cancel"],
 764                    )
 765                });
 766                match answer.next().await {
 767                    Some(0) => true,
 768                    Some(1) => false,
 769                    _ => return Ok(false),
 770                }
 771            } else {
 772                true
 773            };
 774
 775            if should_save {
 776                if can_save {
 777                    cx.update(|cx| item.save(project, cx)).await?;
 778                } else if is_singleton {
 779                    let start_abs_path = project
 780                        .read_with(cx, |project, cx| {
 781                            let worktree = project.visible_worktrees(cx).next()?;
 782                            Some(worktree.read(cx).as_local()?.abs_path().to_path_buf())
 783                        })
 784                        .unwrap_or(Path::new("").into());
 785
 786                    let mut abs_path = cx.update(|cx| cx.prompt_for_new_path(&start_abs_path));
 787                    if let Some(abs_path) = abs_path.next().await.flatten() {
 788                        cx.update(|cx| item.save_as(project, abs_path, cx)).await?;
 789                    } else {
 790                        return Ok(false);
 791                    }
 792                }
 793            }
 794        }
 795        Ok(true)
 796    }
 797
 798    fn can_autosave_item(item: &dyn ItemHandle, cx: &AppContext) -> bool {
 799        let is_deleted = item.project_entry_ids(cx).is_empty();
 800        item.is_dirty(cx) && !item.has_conflict(cx) && item.can_save(cx) && !is_deleted
 801    }
 802
 803    pub fn autosave_item(
 804        item: &dyn ItemHandle,
 805        project: ModelHandle<Project>,
 806        cx: &mut MutableAppContext,
 807    ) -> Task<Result<()>> {
 808        if Self::can_autosave_item(item, cx) {
 809            item.save(project, cx)
 810        } else {
 811            Task::ready(Ok(()))
 812        }
 813    }
 814
 815    pub fn focus_active_item(&mut self, cx: &mut ViewContext<Self>) {
 816        if let Some(active_item) = self.active_item() {
 817            cx.focus(active_item);
 818        }
 819    }
 820
 821    pub fn split(&mut self, direction: SplitDirection, cx: &mut ViewContext<Self>) {
 822        cx.emit(Event::Split(direction));
 823    }
 824
 825    fn deploy_split_menu(&mut self, action: &DeploySplitMenu, cx: &mut ViewContext<Self>) {
 826        self.split_menu.update(cx, |menu, cx| {
 827            menu.show(
 828                action.position,
 829                vec![
 830                    ContextMenuItem::item("Split Right", SplitRight),
 831                    ContextMenuItem::item("Split Left", SplitLeft),
 832                    ContextMenuItem::item("Split Up", SplitUp),
 833                    ContextMenuItem::item("Split Down", SplitDown),
 834                ],
 835                cx,
 836            );
 837        });
 838    }
 839
 840    pub fn toolbar(&self) -> &ViewHandle<Toolbar> {
 841        &self.toolbar
 842    }
 843
 844    fn update_toolbar(&mut self, cx: &mut ViewContext<Self>) {
 845        let active_item = self
 846            .items
 847            .get(self.active_item_index)
 848            .map(|item| item.as_ref());
 849        self.toolbar.update(cx, |toolbar, cx| {
 850            toolbar.set_active_pane_item(active_item, cx);
 851        });
 852    }
 853
 854    fn render_tabs(&mut self, cx: &mut RenderContext<Self>) -> impl Element {
 855        let theme = cx.global::<Settings>().theme.clone();
 856
 857        enum Tabs {}
 858        enum Tab {}
 859        let pane = cx.handle();
 860        MouseEventHandler::new::<Tabs, _, _>(0, cx, |mouse_state, cx| {
 861            let autoscroll = if mem::take(&mut self.autoscroll) {
 862                Some(self.active_item_index)
 863            } else {
 864                None
 865            };
 866
 867            let mut row = Flex::row().scrollable::<Tabs, _>(1, autoscroll, cx);
 868            for (ix, (item, detail)) in self.items.iter().zip(self.tab_details(cx)).enumerate() {
 869                let detail = if detail == 0 { None } else { Some(detail) };
 870                let is_active = ix == self.active_item_index;
 871
 872                row.add_child({
 873                    let tab_style = if is_active {
 874                        theme.workspace.active_tab.clone()
 875                    } else {
 876                        theme.workspace.tab.clone()
 877                    };
 878                    let title = item.tab_content(detail, &tab_style, cx);
 879
 880                    let mut style = if is_active {
 881                        theme.workspace.active_tab.clone()
 882                    } else {
 883                        theme.workspace.tab.clone()
 884                    };
 885                    if ix == 0 {
 886                        style.container.border.left = false;
 887                    }
 888
 889                    MouseEventHandler::new::<Tab, _, _>(ix, cx, |_, cx| {
 890                        Container::new(
 891                            Flex::row()
 892                                .with_child(
 893                                    Align::new({
 894                                        let diameter = 7.0;
 895                                        let icon_color = if item.has_conflict(cx) {
 896                                            Some(style.icon_conflict)
 897                                        } else if item.is_dirty(cx) {
 898                                            Some(style.icon_dirty)
 899                                        } else {
 900                                            None
 901                                        };
 902
 903                                        ConstrainedBox::new(
 904                                            Canvas::new(move |bounds, _, cx| {
 905                                                if let Some(color) = icon_color {
 906                                                    let square = RectF::new(
 907                                                        bounds.origin(),
 908                                                        vec2f(diameter, diameter),
 909                                                    );
 910                                                    cx.scene.push_quad(Quad {
 911                                                        bounds: square,
 912                                                        background: Some(color),
 913                                                        border: Default::default(),
 914                                                        corner_radius: diameter / 2.,
 915                                                    });
 916                                                }
 917                                            })
 918                                            .boxed(),
 919                                        )
 920                                        .with_width(diameter)
 921                                        .with_height(diameter)
 922                                        .boxed()
 923                                    })
 924                                    .boxed(),
 925                                )
 926                                .with_child(
 927                                    Container::new(Align::new(title).boxed())
 928                                        .with_style(ContainerStyle {
 929                                            margin: Margin {
 930                                                left: style.spacing,
 931                                                right: style.spacing,
 932                                                ..Default::default()
 933                                            },
 934                                            ..Default::default()
 935                                        })
 936                                        .boxed(),
 937                                )
 938                                .with_child(
 939                                    Align::new(
 940                                        ConstrainedBox::new(if mouse_state.hovered {
 941                                            let item_id = item.id();
 942                                            enum TabCloseButton {}
 943                                            let icon = Svg::new("icons/x.svg");
 944                                            MouseEventHandler::new::<TabCloseButton, _, _>(
 945                                                item_id,
 946                                                cx,
 947                                                |mouse_state, _| {
 948                                                    if mouse_state.hovered {
 949                                                        icon.with_color(style.icon_close_active)
 950                                                            .boxed()
 951                                                    } else {
 952                                                        icon.with_color(style.icon_close).boxed()
 953                                                    }
 954                                                },
 955                                            )
 956                                            .with_padding(Padding::uniform(4.))
 957                                            .with_cursor_style(CursorStyle::PointingHand)
 958                                            .on_click({
 959                                                let pane = pane.clone();
 960                                                move |_, _, cx| {
 961                                                    cx.dispatch_action(CloseItem {
 962                                                        item_id,
 963                                                        pane: pane.clone(),
 964                                                    })
 965                                                }
 966                                            })
 967                                            .named("close-tab-icon")
 968                                        } else {
 969                                            Empty::new().boxed()
 970                                        })
 971                                        .with_width(style.icon_width)
 972                                        .boxed(),
 973                                    )
 974                                    .boxed(),
 975                                )
 976                                .boxed(),
 977                        )
 978                        .with_style(style.container)
 979                        .boxed()
 980                    })
 981                    .on_mouse_down(move |_, cx| {
 982                        cx.dispatch_action(ActivateItem(ix));
 983                    })
 984                    .boxed()
 985                })
 986            }
 987
 988            row.add_child(
 989                Empty::new()
 990                    .contained()
 991                    .with_border(theme.workspace.tab.container.border)
 992                    .flex(0., true)
 993                    .named("filler"),
 994            );
 995
 996            row.boxed()
 997        })
 998    }
 999
1000    fn tab_details(&self, cx: &AppContext) -> Vec<usize> {
1001        let mut tab_details = (0..self.items.len()).map(|_| 0).collect::<Vec<_>>();
1002
1003        let mut tab_descriptions = HashMap::default();
1004        let mut done = false;
1005        while !done {
1006            done = true;
1007
1008            // Store item indices by their tab description.
1009            for (ix, (item, detail)) in self.items.iter().zip(&tab_details).enumerate() {
1010                if let Some(description) = item.tab_description(*detail, cx) {
1011                    if *detail == 0
1012                        || Some(&description) != item.tab_description(detail - 1, cx).as_ref()
1013                    {
1014                        tab_descriptions
1015                            .entry(description)
1016                            .or_insert(Vec::new())
1017                            .push(ix);
1018                    }
1019                }
1020            }
1021
1022            // If two or more items have the same tab description, increase their level
1023            // of detail and try again.
1024            for (_, item_ixs) in tab_descriptions.drain() {
1025                if item_ixs.len() > 1 {
1026                    done = false;
1027                    for ix in item_ixs {
1028                        tab_details[ix] += 1;
1029                    }
1030                }
1031            }
1032        }
1033
1034        tab_details
1035    }
1036}
1037
1038impl Entity for Pane {
1039    type Event = Event;
1040}
1041
1042impl View for Pane {
1043    fn ui_name() -> &'static str {
1044        "Pane"
1045    }
1046
1047    fn render(&mut self, cx: &mut RenderContext<Self>) -> ElementBox {
1048        enum SplitIcon {}
1049
1050        let this = cx.handle();
1051
1052        Stack::new()
1053            .with_child(
1054                EventHandler::new(if let Some(active_item) = self.active_item() {
1055                    Flex::column()
1056                        .with_child(
1057                            Flex::row()
1058                                .with_child(self.render_tabs(cx).flex(1., true).named("tabs"))
1059                                .with_child(
1060                                    MouseEventHandler::new::<SplitIcon, _, _>(
1061                                        0,
1062                                        cx,
1063                                        |mouse_state, cx| {
1064                                            let theme = &cx.global::<Settings>().theme.workspace;
1065                                            let style =
1066                                                theme.pane_button.style_for(mouse_state, false);
1067                                            Svg::new("icons/split.svg")
1068                                                .with_color(style.color)
1069                                                .constrained()
1070                                                .with_width(style.icon_width)
1071                                                .aligned()
1072                                                .contained()
1073                                                .with_style(style.container)
1074                                                .constrained()
1075                                                .with_width(style.button_width)
1076                                                .with_height(style.button_width)
1077                                                .aligned()
1078                                                .boxed()
1079                                        },
1080                                    )
1081                                    .with_cursor_style(CursorStyle::PointingHand)
1082                                    .on_mouse_down(|position, cx| {
1083                                        cx.dispatch_action(DeploySplitMenu { position });
1084                                    })
1085                                    .boxed(),
1086                                )
1087                                .constrained()
1088                                .with_height(cx.global::<Settings>().theme.workspace.tab.height)
1089                                .boxed(),
1090                        )
1091                        .with_child(ChildView::new(&self.toolbar).boxed())
1092                        .with_child(ChildView::new(active_item).flex(1., true).boxed())
1093                        .boxed()
1094                } else {
1095                    Empty::new().boxed()
1096                })
1097                .on_navigate_mouse_down(move |direction, cx| {
1098                    let this = this.clone();
1099                    match direction {
1100                        NavigationDirection::Back => {
1101                            cx.dispatch_action(GoBack { pane: Some(this) })
1102                        }
1103                        NavigationDirection::Forward => {
1104                            cx.dispatch_action(GoForward { pane: Some(this) })
1105                        }
1106                    }
1107
1108                    true
1109                })
1110                .boxed(),
1111            )
1112            .with_child(ChildView::new(&self.split_menu).boxed())
1113            .named("pane")
1114    }
1115
1116    fn on_focus(&mut self, cx: &mut ViewContext<Self>) {
1117        self.focus_active_item(cx);
1118    }
1119}
1120
1121impl ItemNavHistory {
1122    pub fn push<D: 'static + Any>(&self, data: Option<D>, cx: &mut MutableAppContext) {
1123        self.history.borrow_mut().push(data, self.item.clone(), cx);
1124    }
1125
1126    pub fn pop_backward(&self, cx: &mut MutableAppContext) -> Option<NavigationEntry> {
1127        self.history.borrow_mut().pop(NavigationMode::GoingBack, cx)
1128    }
1129
1130    pub fn pop_forward(&self, cx: &mut MutableAppContext) -> Option<NavigationEntry> {
1131        self.history
1132            .borrow_mut()
1133            .pop(NavigationMode::GoingForward, cx)
1134    }
1135}
1136
1137impl NavHistory {
1138    fn set_mode(&mut self, mode: NavigationMode) {
1139        self.mode = mode;
1140    }
1141
1142    fn disable(&mut self) {
1143        self.mode = NavigationMode::Disabled;
1144    }
1145
1146    fn enable(&mut self) {
1147        self.mode = NavigationMode::Normal;
1148    }
1149
1150    fn pop(&mut self, mode: NavigationMode, cx: &mut MutableAppContext) -> Option<NavigationEntry> {
1151        let entry = match mode {
1152            NavigationMode::Normal | NavigationMode::Disabled | NavigationMode::ClosingItem => {
1153                return None
1154            }
1155            NavigationMode::GoingBack => &mut self.backward_stack,
1156            NavigationMode::GoingForward => &mut self.forward_stack,
1157            NavigationMode::ReopeningClosedItem => &mut self.closed_stack,
1158        }
1159        .pop_back();
1160        if entry.is_some() {
1161            self.did_update(cx);
1162        }
1163        entry
1164    }
1165
1166    fn push<D: 'static + Any>(
1167        &mut self,
1168        data: Option<D>,
1169        item: Rc<dyn WeakItemHandle>,
1170        cx: &mut MutableAppContext,
1171    ) {
1172        match self.mode {
1173            NavigationMode::Disabled => {}
1174            NavigationMode::Normal | NavigationMode::ReopeningClosedItem => {
1175                if self.backward_stack.len() >= MAX_NAVIGATION_HISTORY_LEN {
1176                    self.backward_stack.pop_front();
1177                }
1178                self.backward_stack.push_back(NavigationEntry {
1179                    item,
1180                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
1181                });
1182                self.forward_stack.clear();
1183            }
1184            NavigationMode::GoingBack => {
1185                if self.forward_stack.len() >= MAX_NAVIGATION_HISTORY_LEN {
1186                    self.forward_stack.pop_front();
1187                }
1188                self.forward_stack.push_back(NavigationEntry {
1189                    item,
1190                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
1191                });
1192            }
1193            NavigationMode::GoingForward => {
1194                if self.backward_stack.len() >= MAX_NAVIGATION_HISTORY_LEN {
1195                    self.backward_stack.pop_front();
1196                }
1197                self.backward_stack.push_back(NavigationEntry {
1198                    item,
1199                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
1200                });
1201            }
1202            NavigationMode::ClosingItem => {
1203                if self.closed_stack.len() >= MAX_NAVIGATION_HISTORY_LEN {
1204                    self.closed_stack.pop_front();
1205                }
1206                self.closed_stack.push_back(NavigationEntry {
1207                    item,
1208                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
1209                });
1210            }
1211        }
1212        self.did_update(cx);
1213    }
1214
1215    fn did_update(&self, cx: &mut MutableAppContext) {
1216        if let Some(pane) = self.pane.upgrade(cx) {
1217            cx.defer(move |cx| pane.update(cx, |pane, cx| pane.history_updated(cx)));
1218        }
1219    }
1220}