pane.rs

  1use super::{ItemViewHandle, SplitDirection};
  2use crate::{ItemView, Settings, WeakItemViewHandle, Workspace};
  3use collections::{HashMap, VecDeque};
  4use gpui::{
  5    action,
  6    elements::*,
  7    geometry::{rect::RectF, vector::vec2f},
  8    keymap::Binding,
  9    platform::{CursorStyle, NavigationDirection},
 10    AnyViewHandle, Entity, MutableAppContext, Quad, RenderContext, Task, View, ViewContext,
 11    ViewHandle, WeakViewHandle,
 12};
 13use project::{ProjectEntryId, ProjectPath};
 14use std::{
 15    any::{Any, TypeId},
 16    cell::RefCell,
 17    cmp, mem,
 18    rc::Rc,
 19};
 20use util::ResultExt;
 21
 22action!(Split, SplitDirection);
 23action!(ActivateItem, usize);
 24action!(ActivatePrevItem);
 25action!(ActivateNextItem);
 26action!(CloseActiveItem);
 27action!(CloseInactiveItems);
 28action!(CloseItem, usize);
 29action!(GoBack, Option<WeakViewHandle<Pane>>);
 30action!(GoForward, Option<WeakViewHandle<Pane>>);
 31
 32const MAX_NAVIGATION_HISTORY_LEN: usize = 1024;
 33
 34pub fn init(cx: &mut MutableAppContext) {
 35    cx.add_action(|pane: &mut Pane, action: &ActivateItem, cx| {
 36        pane.activate_item(action.0, cx);
 37    });
 38    cx.add_action(|pane: &mut Pane, _: &ActivatePrevItem, cx| {
 39        pane.activate_prev_item(cx);
 40    });
 41    cx.add_action(|pane: &mut Pane, _: &ActivateNextItem, cx| {
 42        pane.activate_next_item(cx);
 43    });
 44    cx.add_action(|pane: &mut Pane, _: &CloseActiveItem, cx| {
 45        pane.close_active_item(cx);
 46    });
 47    cx.add_action(|pane: &mut Pane, _: &CloseInactiveItems, cx| {
 48        pane.close_inactive_items(cx);
 49    });
 50    cx.add_action(|pane: &mut Pane, action: &CloseItem, cx| {
 51        pane.close_item(action.0, cx);
 52    });
 53    cx.add_action(|pane: &mut Pane, action: &Split, cx| {
 54        pane.split(action.0, cx);
 55    });
 56    cx.add_action(|workspace: &mut Workspace, action: &GoBack, cx| {
 57        Pane::go_back(
 58            workspace,
 59            action
 60                .0
 61                .as_ref()
 62                .and_then(|weak_handle| weak_handle.upgrade(cx)),
 63            cx,
 64        )
 65        .detach();
 66    });
 67    cx.add_action(|workspace: &mut Workspace, action: &GoForward, cx| {
 68        Pane::go_forward(
 69            workspace,
 70            action
 71                .0
 72                .as_ref()
 73                .and_then(|weak_handle| weak_handle.upgrade(cx)),
 74            cx,
 75        )
 76        .detach();
 77    });
 78
 79    cx.add_bindings(vec![
 80        Binding::new("shift-cmd-{", ActivatePrevItem, Some("Pane")),
 81        Binding::new("shift-cmd-}", ActivateNextItem, Some("Pane")),
 82        Binding::new("cmd-w", CloseActiveItem, Some("Pane")),
 83        Binding::new("alt-cmd-w", CloseInactiveItems, Some("Pane")),
 84        Binding::new("cmd-k up", Split(SplitDirection::Up), Some("Pane")),
 85        Binding::new("cmd-k down", Split(SplitDirection::Down), Some("Pane")),
 86        Binding::new("cmd-k left", Split(SplitDirection::Left), Some("Pane")),
 87        Binding::new("cmd-k right", Split(SplitDirection::Right), Some("Pane")),
 88        Binding::new("ctrl--", GoBack(None), Some("Pane")),
 89        Binding::new("shift-ctrl-_", GoForward(None), Some("Pane")),
 90    ]);
 91}
 92
 93pub enum Event {
 94    Activate,
 95    Remove,
 96    Split(SplitDirection),
 97}
 98
 99pub struct Pane {
100    item_views: Vec<(Option<ProjectEntryId>, Box<dyn ItemViewHandle>)>,
101    active_item_index: usize,
102    nav_history: Rc<RefCell<NavHistory>>,
103    toolbars: HashMap<TypeId, Box<dyn ToolbarHandle>>,
104    active_toolbar_type: Option<TypeId>,
105    active_toolbar_visible: bool,
106}
107
108pub trait Toolbar: View {
109    fn active_item_changed(
110        &mut self,
111        item: Option<Box<dyn ItemViewHandle>>,
112        cx: &mut ViewContext<Self>,
113    ) -> bool;
114    fn on_dismiss(&mut self, cx: &mut ViewContext<Self>);
115}
116
117trait ToolbarHandle {
118    fn active_item_changed(
119        &self,
120        item: Option<Box<dyn ItemViewHandle>>,
121        cx: &mut MutableAppContext,
122    ) -> bool;
123    fn on_dismiss(&self, cx: &mut MutableAppContext);
124    fn to_any(&self) -> AnyViewHandle;
125}
126
127pub struct ItemNavHistory {
128    history: Rc<RefCell<NavHistory>>,
129    item_view: Rc<dyn WeakItemViewHandle>,
130}
131
132#[derive(Default)]
133pub struct NavHistory {
134    mode: NavigationMode,
135    backward_stack: VecDeque<NavigationEntry>,
136    forward_stack: VecDeque<NavigationEntry>,
137    paths_by_item: HashMap<usize, ProjectPath>,
138}
139
140#[derive(Copy, Clone)]
141enum NavigationMode {
142    Normal,
143    GoingBack,
144    GoingForward,
145    Disabled,
146}
147
148impl Default for NavigationMode {
149    fn default() -> Self {
150        Self::Normal
151    }
152}
153
154pub struct NavigationEntry {
155    pub item_view: Rc<dyn WeakItemViewHandle>,
156    pub data: Option<Box<dyn Any>>,
157}
158
159impl Pane {
160    pub fn new() -> Self {
161        Self {
162            item_views: Vec::new(),
163            active_item_index: 0,
164            nav_history: Default::default(),
165            toolbars: Default::default(),
166            active_toolbar_type: Default::default(),
167            active_toolbar_visible: false,
168        }
169    }
170
171    pub fn nav_history(&self) -> &Rc<RefCell<NavHistory>> {
172        &self.nav_history
173    }
174
175    pub fn activate(&self, cx: &mut ViewContext<Self>) {
176        cx.emit(Event::Activate);
177    }
178
179    pub fn go_back(
180        workspace: &mut Workspace,
181        pane: Option<ViewHandle<Pane>>,
182        cx: &mut ViewContext<Workspace>,
183    ) -> Task<()> {
184        Self::navigate_history(
185            workspace,
186            pane.unwrap_or_else(|| workspace.active_pane().clone()),
187            NavigationMode::GoingBack,
188            cx,
189        )
190    }
191
192    pub fn go_forward(
193        workspace: &mut Workspace,
194        pane: Option<ViewHandle<Pane>>,
195        cx: &mut ViewContext<Workspace>,
196    ) -> Task<()> {
197        Self::navigate_history(
198            workspace,
199            pane.unwrap_or_else(|| workspace.active_pane().clone()),
200            NavigationMode::GoingForward,
201            cx,
202        )
203    }
204
205    fn navigate_history(
206        workspace: &mut Workspace,
207        pane: ViewHandle<Pane>,
208        mode: NavigationMode,
209        cx: &mut ViewContext<Workspace>,
210    ) -> Task<()> {
211        workspace.activate_pane(pane.clone(), cx);
212
213        let to_load = pane.update(cx, |pane, cx| {
214            // Retrieve the weak item handle from the history.
215            let entry = pane.nav_history.borrow_mut().pop(mode)?;
216
217            // If the item is still present in this pane, then activate it.
218            if let Some(index) = entry
219                .item_view
220                .upgrade(cx)
221                .and_then(|v| pane.index_for_item_view(v.as_ref()))
222            {
223                if let Some(item_view) = pane.active_item() {
224                    pane.nav_history.borrow_mut().set_mode(mode);
225                    item_view.deactivated(cx);
226                    pane.nav_history
227                        .borrow_mut()
228                        .set_mode(NavigationMode::Normal);
229                }
230
231                pane.active_item_index = index;
232                pane.focus_active_item(cx);
233                if let Some(data) = entry.data {
234                    pane.active_item()?.navigate(data, cx);
235                }
236                cx.notify();
237                None
238            }
239            // If the item is no longer present in this pane, then retrieve its
240            // project path in order to reopen it.
241            else {
242                pane.nav_history
243                    .borrow_mut()
244                    .paths_by_item
245                    .get(&entry.item_view.id())
246                    .cloned()
247                    .map(|project_path| (project_path, entry))
248            }
249        });
250
251        if let Some((project_path, entry)) = to_load {
252            // If the item was no longer present, then load it again from its previous path.
253            let pane = pane.downgrade();
254            let task = workspace.load_path(project_path, cx);
255            cx.spawn(|workspace, mut cx| async move {
256                let task = task.await;
257                if let Some(pane) = pane.upgrade(&cx) {
258                    if let Some((project_entry_id, build_item)) = task.log_err() {
259                        pane.update(&mut cx, |pane, cx| {
260                            pane.nav_history.borrow_mut().set_mode(mode);
261                            let item = pane.open_item(project_entry_id, cx, build_item);
262                            pane.nav_history
263                                .borrow_mut()
264                                .set_mode(NavigationMode::Normal);
265                            if let Some(data) = entry.data {
266                                item.navigate(data, cx);
267                            }
268                        });
269                    } else {
270                        workspace
271                            .update(&mut cx, |workspace, cx| {
272                                Self::navigate_history(workspace, pane, mode, cx)
273                            })
274                            .await;
275                    }
276                }
277            })
278        } else {
279            Task::ready(())
280        }
281    }
282
283    pub(crate) fn open_item(
284        &mut self,
285        project_entry_id: ProjectEntryId,
286        cx: &mut ViewContext<Self>,
287        build_editor: impl FnOnce(&mut MutableAppContext) -> Box<dyn ItemViewHandle>,
288    ) -> Box<dyn ItemViewHandle> {
289        for (ix, (existing_entry_id, item_view)) in self.item_views.iter().enumerate() {
290            if *existing_entry_id == Some(project_entry_id) {
291                let item_view = item_view.boxed_clone();
292                self.activate_item(ix, cx);
293                return item_view;
294            }
295        }
296
297        let item_view = build_editor(cx);
298        self.add_item(Some(project_entry_id), item_view.boxed_clone(), cx);
299        item_view
300    }
301
302    pub(crate) fn add_item(
303        &mut self,
304        project_entry_id: Option<ProjectEntryId>,
305        mut item: Box<dyn ItemViewHandle>,
306        cx: &mut ViewContext<Self>,
307    ) {
308        item.set_nav_history(self.nav_history.clone(), cx);
309        item.added_to_pane(cx);
310        let item_idx = cmp::min(self.active_item_index + 1, self.item_views.len());
311        self.item_views.insert(item_idx, (project_entry_id, item));
312        self.activate_item(item_idx, cx);
313        cx.notify();
314    }
315
316    pub fn item_views(&self) -> impl Iterator<Item = &Box<dyn ItemViewHandle>> {
317        self.item_views.iter().map(|(_, view)| view)
318    }
319
320    pub fn active_item(&self) -> Option<Box<dyn ItemViewHandle>> {
321        self.item_views
322            .get(self.active_item_index)
323            .map(|(_, view)| view.clone())
324    }
325
326    pub fn project_entry_id_for_item(&self, item: &dyn ItemViewHandle) -> Option<ProjectEntryId> {
327        self.item_views.iter().find_map(|(entry_id, existing)| {
328            if existing.id() == item.id() {
329                *entry_id
330            } else {
331                None
332            }
333        })
334    }
335
336    pub fn item_for_entry(&self, entry_id: ProjectEntryId) -> Option<Box<dyn ItemViewHandle>> {
337        self.item_views.iter().find_map(|(id, view)| {
338            if *id == Some(entry_id) {
339                Some(view.boxed_clone())
340            } else {
341                None
342            }
343        })
344    }
345
346    pub fn index_for_item_view(&self, item_view: &dyn ItemViewHandle) -> Option<usize> {
347        self.item_views
348            .iter()
349            .position(|(_, i)| i.id() == item_view.id())
350    }
351
352    pub fn index_for_item(&self, item: &dyn ItemViewHandle) -> Option<usize> {
353        self.item_views
354            .iter()
355            .position(|(_, my_item)| my_item.id() == item.id())
356    }
357
358    pub fn activate_item(&mut self, index: usize, cx: &mut ViewContext<Self>) {
359        if index < self.item_views.len() {
360            let prev_active_item_ix = mem::replace(&mut self.active_item_index, index);
361            if prev_active_item_ix != self.active_item_index
362                && prev_active_item_ix < self.item_views.len()
363            {
364                self.item_views[prev_active_item_ix].1.deactivated(cx);
365            }
366            self.update_active_toolbar(cx);
367            self.focus_active_item(cx);
368            self.activate(cx);
369            cx.notify();
370        }
371    }
372
373    pub fn activate_prev_item(&mut self, cx: &mut ViewContext<Self>) {
374        let mut index = self.active_item_index;
375        if index > 0 {
376            index -= 1;
377        } else if self.item_views.len() > 0 {
378            index = self.item_views.len() - 1;
379        }
380        self.activate_item(index, cx);
381    }
382
383    pub fn activate_next_item(&mut self, cx: &mut ViewContext<Self>) {
384        let mut index = self.active_item_index;
385        if index + 1 < self.item_views.len() {
386            index += 1;
387        } else {
388            index = 0;
389        }
390        self.activate_item(index, cx);
391    }
392
393    pub fn close_active_item(&mut self, cx: &mut ViewContext<Self>) {
394        if !self.item_views.is_empty() {
395            self.close_item(self.item_views[self.active_item_index].1.id(), cx)
396        }
397    }
398
399    pub fn close_inactive_items(&mut self, cx: &mut ViewContext<Self>) {
400        if !self.item_views.is_empty() {
401            let active_item_id = self.item_views[self.active_item_index].1.id();
402            self.close_items(cx, |id| id != active_item_id);
403        }
404    }
405
406    pub fn close_item(&mut self, view_id_to_close: usize, cx: &mut ViewContext<Self>) {
407        self.close_items(cx, |view_id| view_id == view_id_to_close);
408    }
409
410    pub fn close_items(
411        &mut self,
412        cx: &mut ViewContext<Self>,
413        should_close: impl Fn(usize) -> bool,
414    ) {
415        let mut item_ix = 0;
416        let mut new_active_item_index = self.active_item_index;
417        self.item_views.retain(|(_, item_view)| {
418            if should_close(item_view.id()) {
419                if item_ix == self.active_item_index {
420                    item_view.deactivated(cx);
421                }
422
423                if item_ix < self.active_item_index {
424                    new_active_item_index -= 1;
425                }
426
427                let mut nav_history = self.nav_history.borrow_mut();
428                if let Some(path) = item_view.project_path(cx) {
429                    nav_history.paths_by_item.insert(item_view.id(), path);
430                } else {
431                    nav_history.paths_by_item.remove(&item_view.id());
432                }
433
434                item_ix += 1;
435                false
436            } else {
437                item_ix += 1;
438                true
439            }
440        });
441
442        if self.item_views.is_empty() {
443            cx.emit(Event::Remove);
444        } else {
445            self.active_item_index = cmp::min(new_active_item_index, self.item_views.len() - 1);
446            self.focus_active_item(cx);
447            self.activate(cx);
448        }
449        self.update_active_toolbar(cx);
450
451        cx.notify();
452    }
453
454    fn focus_active_item(&mut self, cx: &mut ViewContext<Self>) {
455        if let Some(active_item) = self.active_item() {
456            cx.focus(active_item);
457        }
458    }
459
460    pub fn split(&mut self, direction: SplitDirection, cx: &mut ViewContext<Self>) {
461        cx.emit(Event::Split(direction));
462    }
463
464    pub fn show_toolbar<F, V>(&mut self, cx: &mut ViewContext<Self>, build_toolbar: F)
465    where
466        F: FnOnce(&mut ViewContext<V>) -> V,
467        V: Toolbar,
468    {
469        let type_id = TypeId::of::<V>();
470        if self.active_toolbar_type != Some(type_id) {
471            self.dismiss_toolbar(cx);
472
473            let active_item = self.active_item();
474            self.toolbars
475                .entry(type_id)
476                .or_insert_with(|| Box::new(cx.add_view(build_toolbar)));
477
478            self.active_toolbar_type = Some(type_id);
479            self.active_toolbar_visible =
480                self.toolbars[&type_id].active_item_changed(active_item, cx);
481            cx.notify();
482        }
483    }
484
485    pub fn dismiss_toolbar(&mut self, cx: &mut ViewContext<Self>) {
486        if let Some(active_toolbar_type) = self.active_toolbar_type.take() {
487            self.toolbars
488                .get_mut(&active_toolbar_type)
489                .unwrap()
490                .on_dismiss(cx);
491            self.active_toolbar_visible = false;
492            self.focus_active_item(cx);
493            cx.notify();
494        }
495    }
496
497    pub fn toolbar<T: Toolbar>(&self) -> Option<ViewHandle<T>> {
498        self.toolbars
499            .get(&TypeId::of::<T>())
500            .and_then(|toolbar| toolbar.to_any().downcast())
501    }
502
503    pub fn active_toolbar(&self) -> Option<AnyViewHandle> {
504        let type_id = self.active_toolbar_type?;
505        let toolbar = self.toolbars.get(&type_id)?;
506        if self.active_toolbar_visible {
507            Some(toolbar.to_any())
508        } else {
509            None
510        }
511    }
512
513    fn update_active_toolbar(&mut self, cx: &mut ViewContext<Self>) {
514        let active_item = self.item_views.get(self.active_item_index);
515        for (toolbar_type_id, toolbar) in &self.toolbars {
516            let visible = toolbar.active_item_changed(active_item.map(|i| i.1.clone()), cx);
517            if Some(*toolbar_type_id) == self.active_toolbar_type {
518                self.active_toolbar_visible = visible;
519            }
520        }
521    }
522
523    fn render_tabs(&self, cx: &mut RenderContext<Self>) -> ElementBox {
524        let theme = cx.app_state::<Settings>().theme.clone();
525
526        enum Tabs {}
527        let tabs = MouseEventHandler::new::<Tabs, _, _>(0, cx, |mouse_state, cx| {
528            let mut row = Flex::row();
529            for (ix, (_, item_view)) in self.item_views.iter().enumerate() {
530                let is_active = ix == self.active_item_index;
531
532                row.add_child({
533                    let tab_style = if is_active {
534                        theme.workspace.active_tab.clone()
535                    } else {
536                        theme.workspace.tab.clone()
537                    };
538                    let title = item_view.tab_content(&tab_style, cx);
539
540                    let mut style = if is_active {
541                        theme.workspace.active_tab.clone()
542                    } else {
543                        theme.workspace.tab.clone()
544                    };
545                    if ix == 0 {
546                        style.container.border.left = false;
547                    }
548
549                    EventHandler::new(
550                        Container::new(
551                            Flex::row()
552                                .with_child(
553                                    Align::new({
554                                        let diameter = 7.0;
555                                        let icon_color = if item_view.has_conflict(cx) {
556                                            Some(style.icon_conflict)
557                                        } else if item_view.is_dirty(cx) {
558                                            Some(style.icon_dirty)
559                                        } else {
560                                            None
561                                        };
562
563                                        ConstrainedBox::new(
564                                            Canvas::new(move |bounds, _, cx| {
565                                                if let Some(color) = icon_color {
566                                                    let square = RectF::new(
567                                                        bounds.origin(),
568                                                        vec2f(diameter, diameter),
569                                                    );
570                                                    cx.scene.push_quad(Quad {
571                                                        bounds: square,
572                                                        background: Some(color),
573                                                        border: Default::default(),
574                                                        corner_radius: diameter / 2.,
575                                                    });
576                                                }
577                                            })
578                                            .boxed(),
579                                        )
580                                        .with_width(diameter)
581                                        .with_height(diameter)
582                                        .boxed()
583                                    })
584                                    .boxed(),
585                                )
586                                .with_child(
587                                    Container::new(Align::new(title).boxed())
588                                        .with_style(ContainerStyle {
589                                            margin: Margin {
590                                                left: style.spacing,
591                                                right: style.spacing,
592                                                ..Default::default()
593                                            },
594                                            ..Default::default()
595                                        })
596                                        .boxed(),
597                                )
598                                .with_child(
599                                    Align::new(
600                                        ConstrainedBox::new(if mouse_state.hovered {
601                                            let item_id = item_view.id();
602                                            enum TabCloseButton {}
603                                            let icon = Svg::new("icons/x.svg");
604                                            MouseEventHandler::new::<TabCloseButton, _, _>(
605                                                item_id,
606                                                cx,
607                                                |mouse_state, _| {
608                                                    if mouse_state.hovered {
609                                                        icon.with_color(style.icon_close_active)
610                                                            .boxed()
611                                                    } else {
612                                                        icon.with_color(style.icon_close).boxed()
613                                                    }
614                                                },
615                                            )
616                                            .with_padding(Padding::uniform(4.))
617                                            .with_cursor_style(CursorStyle::PointingHand)
618                                            .on_click(move |cx| {
619                                                cx.dispatch_action(CloseItem(item_id))
620                                            })
621                                            .named("close-tab-icon")
622                                        } else {
623                                            Empty::new().boxed()
624                                        })
625                                        .with_width(style.icon_width)
626                                        .boxed(),
627                                    )
628                                    .boxed(),
629                                )
630                                .boxed(),
631                        )
632                        .with_style(style.container)
633                        .boxed(),
634                    )
635                    .on_mouse_down(move |cx| {
636                        cx.dispatch_action(ActivateItem(ix));
637                        true
638                    })
639                    .boxed()
640                })
641            }
642
643            row.add_child(
644                Empty::new()
645                    .contained()
646                    .with_border(theme.workspace.tab.container.border)
647                    .flexible(0., true)
648                    .named("filler"),
649            );
650
651            row.boxed()
652        });
653
654        ConstrainedBox::new(tabs.boxed())
655            .with_height(theme.workspace.tab.height)
656            .named("tabs")
657    }
658}
659
660impl Entity for Pane {
661    type Event = Event;
662}
663
664impl View for Pane {
665    fn ui_name() -> &'static str {
666        "Pane"
667    }
668
669    fn render(&mut self, cx: &mut RenderContext<Self>) -> ElementBox {
670        let this = cx.handle();
671
672        EventHandler::new(if let Some(active_item) = self.active_item() {
673            Flex::column()
674                .with_child(self.render_tabs(cx))
675                .with_children(
676                    self.active_toolbar()
677                        .as_ref()
678                        .map(|view| ChildView::new(view).boxed()),
679                )
680                .with_child(ChildView::new(active_item).flexible(1., true).boxed())
681                .boxed()
682        } else {
683            Empty::new().boxed()
684        })
685        .on_navigate_mouse_down(move |direction, cx| {
686            let this = this.clone();
687            match direction {
688                NavigationDirection::Back => cx.dispatch_action(GoBack(Some(this))),
689                NavigationDirection::Forward => cx.dispatch_action(GoForward(Some(this))),
690            }
691
692            true
693        })
694        .named("pane")
695    }
696
697    fn on_focus(&mut self, cx: &mut ViewContext<Self>) {
698        self.focus_active_item(cx);
699    }
700}
701
702impl<T: Toolbar> ToolbarHandle for ViewHandle<T> {
703    fn active_item_changed(
704        &self,
705        item: Option<Box<dyn ItemViewHandle>>,
706        cx: &mut MutableAppContext,
707    ) -> bool {
708        self.update(cx, |this, cx| this.active_item_changed(item, cx))
709    }
710
711    fn on_dismiss(&self, cx: &mut MutableAppContext) {
712        self.update(cx, |this, cx| this.on_dismiss(cx));
713    }
714
715    fn to_any(&self) -> AnyViewHandle {
716        self.into()
717    }
718}
719
720impl ItemNavHistory {
721    pub fn new<T: ItemView>(history: Rc<RefCell<NavHistory>>, item_view: &ViewHandle<T>) -> Self {
722        Self {
723            history,
724            item_view: Rc::new(item_view.downgrade()),
725        }
726    }
727
728    pub fn history(&self) -> Rc<RefCell<NavHistory>> {
729        self.history.clone()
730    }
731
732    pub fn push<D: 'static + Any>(&self, data: Option<D>) {
733        self.history.borrow_mut().push(data, self.item_view.clone());
734    }
735}
736
737impl NavHistory {
738    pub fn disable(&mut self) {
739        self.mode = NavigationMode::Disabled;
740    }
741
742    pub fn enable(&mut self) {
743        self.mode = NavigationMode::Normal;
744    }
745
746    pub fn pop_backward(&mut self) -> Option<NavigationEntry> {
747        self.backward_stack.pop_back()
748    }
749
750    pub fn pop_forward(&mut self) -> Option<NavigationEntry> {
751        self.forward_stack.pop_back()
752    }
753
754    fn pop(&mut self, mode: NavigationMode) -> Option<NavigationEntry> {
755        match mode {
756            NavigationMode::Normal | NavigationMode::Disabled => None,
757            NavigationMode::GoingBack => self.pop_backward(),
758            NavigationMode::GoingForward => self.pop_forward(),
759        }
760    }
761
762    fn set_mode(&mut self, mode: NavigationMode) {
763        self.mode = mode;
764    }
765
766    pub fn push<D: 'static + Any>(
767        &mut self,
768        data: Option<D>,
769        item_view: Rc<dyn WeakItemViewHandle>,
770    ) {
771        match self.mode {
772            NavigationMode::Disabled => {}
773            NavigationMode::Normal => {
774                if self.backward_stack.len() >= MAX_NAVIGATION_HISTORY_LEN {
775                    self.backward_stack.pop_front();
776                }
777                self.backward_stack.push_back(NavigationEntry {
778                    item_view,
779                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
780                });
781                self.forward_stack.clear();
782            }
783            NavigationMode::GoingBack => {
784                if self.forward_stack.len() >= MAX_NAVIGATION_HISTORY_LEN {
785                    self.forward_stack.pop_front();
786                }
787                self.forward_stack.push_back(NavigationEntry {
788                    item_view,
789                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
790                });
791            }
792            NavigationMode::GoingForward => {
793                if self.backward_stack.len() >= MAX_NAVIGATION_HISTORY_LEN {
794                    self.backward_stack.pop_front();
795                }
796                self.backward_stack.push_back(NavigationEntry {
797                    item_view,
798                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
799                });
800            }
801        }
802    }
803}