dock.rs

  1use collections::HashMap;
  2use gpui::{
  3    actions,
  4    elements::{ChildView, Container, Empty, MouseEventHandler, Side, Svg},
  5    impl_internal_actions, Border, CursorStyle, Element, ElementBox, Entity, MouseButton,
  6    MutableAppContext, RenderContext, View, ViewContext, ViewHandle, WeakViewHandle,
  7};
  8use serde::Deserialize;
  9use settings::{DockAnchor, Settings};
 10use theme::Theme;
 11
 12use crate::{sidebar::SidebarSide, ItemHandle, Pane, StatusItemView, Workspace};
 13
 14#[derive(PartialEq, Clone, Deserialize)]
 15pub struct MoveDock(pub DockAnchor);
 16
 17#[derive(PartialEq, Clone)]
 18pub struct AddDefaultItemToDock;
 19
 20actions!(
 21    dock,
 22    [
 23        FocusDock,
 24        HideDock,
 25        AnchorDockRight,
 26        AnchorDockBottom,
 27        ExpandDock
 28    ]
 29);
 30impl_internal_actions!(dock, [MoveDock, AddDefaultItemToDock]);
 31
 32pub fn init(cx: &mut MutableAppContext) {
 33    cx.add_action(Dock::focus_dock);
 34    cx.add_action(Dock::hide_dock);
 35    cx.add_action(Dock::move_dock);
 36    cx.add_action(
 37        |workspace: &mut Workspace, _: &AnchorDockRight, cx: &mut ViewContext<Workspace>| {
 38            Dock::move_dock(workspace, &MoveDock(DockAnchor::Right), cx)
 39        },
 40    );
 41    cx.add_action(
 42        |workspace: &mut Workspace, _: &AnchorDockBottom, cx: &mut ViewContext<Workspace>| {
 43            Dock::move_dock(workspace, &MoveDock(DockAnchor::Bottom), cx)
 44        },
 45    );
 46    cx.add_action(
 47        |workspace: &mut Workspace, _: &ExpandDock, cx: &mut ViewContext<Workspace>| {
 48            Dock::move_dock(workspace, &MoveDock(DockAnchor::Expanded), cx)
 49        },
 50    );
 51}
 52
 53#[derive(Copy, Clone, PartialEq, Eq, Debug)]
 54pub enum DockPosition {
 55    Shown(DockAnchor),
 56    Hidden(DockAnchor),
 57}
 58
 59impl Default for DockPosition {
 60    fn default() -> Self {
 61        DockPosition::Hidden(Default::default())
 62    }
 63}
 64
 65pub fn icon_for_dock_anchor(anchor: DockAnchor) -> &'static str {
 66    match anchor {
 67        DockAnchor::Right => "icons/dock_right_12.svg",
 68        DockAnchor::Bottom => "icons/dock_bottom_12.svg",
 69        DockAnchor::Expanded => "icons/dock_modal_12.svg",
 70    }
 71}
 72
 73impl DockPosition {
 74    fn is_visible(&self) -> bool {
 75        match self {
 76            DockPosition::Shown(_) => true,
 77            DockPosition::Hidden(_) => false,
 78        }
 79    }
 80
 81    fn anchor(&self) -> DockAnchor {
 82        match self {
 83            DockPosition::Shown(anchor) | DockPosition::Hidden(anchor) => *anchor,
 84        }
 85    }
 86
 87    fn hide(self) -> Self {
 88        match self {
 89            DockPosition::Shown(anchor) => DockPosition::Hidden(anchor),
 90            DockPosition::Hidden(_) => self,
 91        }
 92    }
 93
 94    fn show(self) -> Self {
 95        match self {
 96            DockPosition::Hidden(anchor) => DockPosition::Shown(anchor),
 97            DockPosition::Shown(_) => self,
 98        }
 99    }
100}
101
102pub type DefaultItemFactory =
103    fn(&mut Workspace, &mut ViewContext<Workspace>) -> Box<dyn ItemHandle>;
104
105pub struct Dock {
106    position: DockPosition,
107    panel_sizes: HashMap<DockAnchor, f32>,
108    pane: ViewHandle<Pane>,
109    default_item_factory: DefaultItemFactory,
110}
111
112impl Dock {
113    pub fn new(cx: &mut ViewContext<Workspace>, default_item_factory: DefaultItemFactory) -> Self {
114        let anchor = cx.global::<Settings>().default_dock_anchor;
115        let pane = cx.add_view(|cx| Pane::new(Some(anchor), cx));
116        pane.update(cx, |pane, cx| {
117            pane.set_active(false, cx);
118        });
119        let pane_id = pane.id();
120        cx.subscribe(&pane, move |workspace, _, event, cx| {
121            workspace.handle_pane_event(pane_id, event, cx);
122        })
123        .detach();
124
125        Self {
126            pane,
127            panel_sizes: Default::default(),
128            position: DockPosition::Hidden(anchor),
129            default_item_factory,
130        }
131    }
132
133    pub fn pane(&self) -> &ViewHandle<Pane> {
134        &self.pane
135    }
136
137    pub fn visible_pane(&self) -> Option<&ViewHandle<Pane>> {
138        self.position.is_visible().then(|| self.pane())
139    }
140
141    pub fn is_anchored_at(&self, anchor: DockAnchor) -> bool {
142        self.position.is_visible() && self.position.anchor() == anchor
143    }
144
145    fn set_dock_position(
146        workspace: &mut Workspace,
147        new_position: DockPosition,
148        cx: &mut ViewContext<Workspace>,
149    ) {
150        workspace.dock.position = new_position;
151        // Tell the pane about the new anchor position
152        workspace.dock.pane.update(cx, |pane, cx| {
153            pane.set_docked(Some(new_position.anchor()), cx)
154        });
155
156        if workspace.dock.position.is_visible() {
157            // Close the right sidebar if the dock is on the right side and the right sidebar is open
158            if workspace.dock.position.anchor() == DockAnchor::Right {
159                if workspace.right_sidebar().read(cx).is_open() {
160                    workspace.toggle_sidebar(SidebarSide::Right, cx);
161                }
162            }
163
164            // Ensure that the pane has at least one item or construct a default item to put in it
165            let pane = workspace.dock.pane.clone();
166            if pane.read(cx).items().next().is_none() {
167                let item_to_add = (workspace.dock.default_item_factory)(workspace, cx);
168                // Adding the item focuses the pane by default
169                Pane::add_item(workspace, &pane, item_to_add, true, true, None, cx);
170            } else {
171                cx.focus(pane);
172            }
173        } else if let Some(last_active_center_pane) = workspace.last_active_center_pane.clone() {
174            cx.focus(last_active_center_pane);
175        }
176        cx.emit(crate::Event::DockAnchorChanged);
177        cx.notify();
178    }
179
180    pub fn hide(workspace: &mut Workspace, cx: &mut ViewContext<Workspace>) {
181        Self::set_dock_position(workspace, workspace.dock.position.hide(), cx);
182    }
183
184    pub fn show(workspace: &mut Workspace, cx: &mut ViewContext<Workspace>) {
185        Self::set_dock_position(workspace, workspace.dock.position.show(), cx);
186    }
187
188    pub fn hide_on_sidebar_shown(
189        workspace: &mut Workspace,
190        sidebar_side: SidebarSide,
191        cx: &mut ViewContext<Workspace>,
192    ) {
193        if (sidebar_side == SidebarSide::Right && workspace.dock.is_anchored_at(DockAnchor::Right))
194            || workspace.dock.is_anchored_at(DockAnchor::Expanded)
195        {
196            Self::hide(workspace, cx);
197        }
198    }
199
200    fn focus_dock(workspace: &mut Workspace, _: &FocusDock, cx: &mut ViewContext<Workspace>) {
201        Self::set_dock_position(workspace, workspace.dock.position.show(), cx);
202    }
203
204    fn hide_dock(workspace: &mut Workspace, _: &HideDock, cx: &mut ViewContext<Workspace>) {
205        Self::set_dock_position(workspace, workspace.dock.position.hide(), cx);
206    }
207
208    fn move_dock(
209        workspace: &mut Workspace,
210        &MoveDock(new_anchor): &MoveDock,
211        cx: &mut ViewContext<Workspace>,
212    ) {
213        Self::set_dock_position(workspace, DockPosition::Shown(new_anchor), cx);
214    }
215
216    pub fn render(
217        &self,
218        theme: &Theme,
219        anchor: DockAnchor,
220        cx: &mut RenderContext<Workspace>,
221    ) -> Option<ElementBox> {
222        let style = &theme.workspace.dock;
223
224        self.position
225            .is_visible()
226            .then(|| self.position.anchor())
227            .filter(|current_anchor| *current_anchor == anchor)
228            .map(|anchor| match anchor {
229                DockAnchor::Bottom | DockAnchor::Right => {
230                    let mut panel_style = style.panel.clone();
231                    let (resize_side, initial_size) = if anchor == DockAnchor::Bottom {
232                        panel_style.border = Border {
233                            top: true,
234                            bottom: false,
235                            left: false,
236                            right: false,
237                            ..panel_style.border
238                        };
239
240                        (Side::Top, style.initial_size_bottom)
241                    } else {
242                        panel_style.border = Border {
243                            top: false,
244                            bottom: false,
245                            left: true,
246                            right: false,
247                            ..panel_style.border
248                        };
249                        (Side::Left, style.initial_size_right)
250                    };
251
252                    enum DockResizeHandle {}
253
254                    let resizable = Container::new(ChildView::new(self.pane.clone()).boxed())
255                        .with_style(panel_style)
256                        .with_resize_handle::<DockResizeHandle, _>(
257                            resize_side as usize,
258                            resize_side,
259                            4.,
260                            self.panel_sizes
261                                .get(&anchor)
262                                .copied()
263                                .unwrap_or(initial_size),
264                            cx,
265                        );
266
267                    let size = resizable.current_size();
268                    let workspace = cx.handle();
269                    cx.defer(move |cx| {
270                        if let Some(workspace) = workspace.upgrade(cx) {
271                            workspace.update(cx, |workspace, _| {
272                                workspace.dock.panel_sizes.insert(anchor, size);
273                            })
274                        }
275                    });
276
277                    resizable.flex(5., false).boxed()
278                }
279                DockAnchor::Expanded => {
280                    enum ExpandedDockWash {}
281                    enum ExpandedDockPane {}
282                    Container::new(
283                        MouseEventHandler::<ExpandedDockWash>::new(0, cx, |_state, cx| {
284                            MouseEventHandler::<ExpandedDockPane>::new(0, cx, |_state, _cx| {
285                                ChildView::new(self.pane.clone()).boxed()
286                            })
287                            .capture_all()
288                            .contained()
289                            .with_style(style.maximized)
290                            .boxed()
291                        })
292                        .capture_all()
293                        .on_down(MouseButton::Left, |_, cx| {
294                            cx.dispatch_action(HideDock);
295                        })
296                        .with_cursor_style(CursorStyle::Arrow)
297                        .boxed(),
298                    )
299                    .with_background_color(style.wash_color)
300                    .boxed()
301                }
302            })
303    }
304}
305
306pub struct ToggleDockButton {
307    workspace: WeakViewHandle<Workspace>,
308}
309
310impl ToggleDockButton {
311    pub fn new(workspace: ViewHandle<Workspace>, cx: &mut ViewContext<Self>) -> Self {
312        // When dock moves, redraw so that the icon and toggle status matches.
313        cx.subscribe(&workspace, |_, _, _, cx| cx.notify()).detach();
314
315        Self {
316            workspace: workspace.downgrade(),
317        }
318    }
319}
320
321impl Entity for ToggleDockButton {
322    type Event = ();
323}
324
325impl View for ToggleDockButton {
326    fn ui_name() -> &'static str {
327        "Dock Toggle"
328    }
329
330    fn render(&mut self, cx: &mut gpui::RenderContext<'_, Self>) -> ElementBox {
331        let workspace = self.workspace.upgrade(cx);
332
333        if workspace.is_none() {
334            return Empty::new().boxed();
335        }
336
337        let dock_position = workspace.unwrap().read(cx).dock.position;
338
339        let theme = cx.global::<Settings>().theme.clone();
340        let button = MouseEventHandler::<Self>::new(0, cx, {
341            let theme = theme.clone();
342            move |state, _| {
343                let style = theme
344                    .workspace
345                    .status_bar
346                    .sidebar_buttons
347                    .item
348                    .style_for(state, dock_position.is_visible());
349
350                Svg::new(icon_for_dock_anchor(dock_position.anchor()))
351                    .with_color(style.icon_color)
352                    .constrained()
353                    .with_width(style.icon_size)
354                    .with_height(style.icon_size)
355                    .contained()
356                    .with_style(style.container)
357                    .boxed()
358            }
359        })
360        .with_cursor_style(CursorStyle::PointingHand);
361
362        if dock_position.is_visible() {
363            button
364                .on_click(MouseButton::Left, |_, cx| {
365                    cx.dispatch_action(HideDock);
366                })
367                .with_tooltip::<Self, _>(
368                    0,
369                    "Hide Dock".into(),
370                    Some(Box::new(HideDock)),
371                    theme.tooltip.clone(),
372                    cx,
373                )
374        } else {
375            button
376                .on_click(MouseButton::Left, |_, cx| {
377                    cx.dispatch_action(FocusDock);
378                })
379                .with_tooltip::<Self, _>(
380                    0,
381                    "Focus Dock".into(),
382                    Some(Box::new(FocusDock)),
383                    theme.tooltip.clone(),
384                    cx,
385                )
386        }
387        .boxed()
388    }
389}
390
391impl StatusItemView for ToggleDockButton {
392    fn set_active_pane_item(
393        &mut self,
394        _active_pane_item: Option<&dyn crate::ItemHandle>,
395        _cx: &mut ViewContext<Self>,
396    ) {
397        //Not applicable
398    }
399}
400
401#[cfg(test)]
402mod tests {
403    use std::ops::{Deref, DerefMut};
404
405    use gpui::{AppContext, TestAppContext, UpdateView, ViewContext};
406    use project::{FakeFs, Project};
407    use settings::Settings;
408
409    use super::*;
410    use crate::{sidebar::Sidebar, tests::TestItem, ItemHandle, Workspace};
411
412    pub fn default_item_factory(
413        _workspace: &mut Workspace,
414        cx: &mut ViewContext<Workspace>,
415    ) -> Box<dyn ItemHandle> {
416        Box::new(cx.add_view(|_| TestItem::new()))
417    }
418
419    #[gpui::test]
420    async fn test_dock_hides_when_pane_empty(cx: &mut TestAppContext) {
421        let mut cx = DockTestContext::new(cx).await;
422
423        // Closing the last item in the dock hides the dock
424        cx.move_dock(DockAnchor::Right);
425        let old_items = cx.dock_items();
426        assert!(!old_items.is_empty());
427        cx.close_dock_items().await;
428        cx.assert_dock_position(DockPosition::Hidden(DockAnchor::Right));
429
430        // Reopening the dock adds a new item
431        cx.move_dock(DockAnchor::Right);
432        let new_items = cx.dock_items();
433        assert!(!new_items.is_empty());
434        assert!(new_items
435            .into_iter()
436            .all(|new_item| !old_items.contains(&new_item)));
437    }
438
439    #[gpui::test]
440    async fn test_dock_panel_collisions(cx: &mut TestAppContext) {
441        let mut cx = DockTestContext::new(cx).await;
442
443        // Dock closes when expanded for either panel
444        cx.move_dock(DockAnchor::Expanded);
445        cx.open_sidebar(SidebarSide::Left);
446        cx.assert_dock_position(DockPosition::Hidden(DockAnchor::Expanded));
447        cx.close_sidebar(SidebarSide::Left);
448        cx.move_dock(DockAnchor::Expanded);
449        cx.open_sidebar(SidebarSide::Right);
450        cx.assert_dock_position(DockPosition::Hidden(DockAnchor::Expanded));
451
452        // Dock closes in the right position if the right sidebar is opened
453        cx.move_dock(DockAnchor::Right);
454        cx.open_sidebar(SidebarSide::Left);
455        cx.assert_dock_position(DockPosition::Shown(DockAnchor::Right));
456        cx.open_sidebar(SidebarSide::Right);
457        cx.assert_dock_position(DockPosition::Hidden(DockAnchor::Right));
458        cx.close_sidebar(SidebarSide::Right);
459
460        // Dock in bottom position ignores sidebars
461        cx.move_dock(DockAnchor::Bottom);
462        cx.open_sidebar(SidebarSide::Left);
463        cx.open_sidebar(SidebarSide::Right);
464        cx.assert_dock_position(DockPosition::Shown(DockAnchor::Bottom));
465
466        // Opening the dock in the right position closes the right sidebar
467        cx.move_dock(DockAnchor::Right);
468        cx.assert_sidebar_closed(SidebarSide::Right);
469    }
470
471    #[gpui::test]
472    async fn test_focusing_panes_shows_and_hides_dock(cx: &mut TestAppContext) {
473        let mut cx = DockTestContext::new(cx).await;
474
475        // Focusing an item not in the dock when expanded hides the dock
476        let center_item = cx.add_item_to_center_pane();
477        cx.move_dock(DockAnchor::Expanded);
478        let dock_item = cx
479            .dock_items()
480            .get(0)
481            .cloned()
482            .expect("Dock should have an item at this point");
483        center_item.update(&mut cx, |_, cx| cx.focus_self());
484        cx.assert_dock_position(DockPosition::Hidden(DockAnchor::Expanded));
485
486        // Focusing an item not in the dock when not expanded, leaves the dock open but inactive
487        cx.move_dock(DockAnchor::Right);
488        center_item.update(&mut cx, |_, cx| cx.focus_self());
489        cx.assert_dock_position(DockPosition::Shown(DockAnchor::Right));
490        cx.assert_dock_pane_inactive();
491        cx.assert_workspace_pane_active();
492
493        // Focusing an item in the dock activates it's pane
494        dock_item.update(&mut cx, |_, cx| cx.focus_self());
495        cx.assert_dock_position(DockPosition::Shown(DockAnchor::Right));
496        cx.assert_dock_pane_active();
497        cx.assert_workspace_pane_inactive();
498    }
499
500    #[gpui::test]
501    async fn test_toggle_dock_focus(cx: &mut TestAppContext) {
502        let cx = DockTestContext::new(cx).await;
503
504        cx.move_dock(DockAnchor::Right);
505        cx.assert_dock_pane_active();
506        cx.hide_dock();
507        cx.move_dock(DockAnchor::Right);
508        cx.assert_dock_pane_active();
509    }
510
511    struct DockTestContext<'a> {
512        pub cx: &'a mut TestAppContext,
513        pub window_id: usize,
514        pub workspace: ViewHandle<Workspace>,
515    }
516
517    impl<'a> DockTestContext<'a> {
518        pub async fn new(cx: &'a mut TestAppContext) -> DockTestContext<'a> {
519            Settings::test_async(cx);
520            let fs = FakeFs::new(cx.background());
521
522            cx.update(|cx| init(cx));
523            let project = Project::test(fs, [], cx).await;
524            let (window_id, workspace) =
525                cx.add_window(|cx| Workspace::new(project, default_item_factory, cx));
526
527            workspace.update(cx, |workspace, cx| {
528                let left_panel = cx.add_view(|_| TestItem::new());
529                workspace.left_sidebar().update(cx, |sidebar, cx| {
530                    sidebar.add_item(
531                        "icons/folder_tree_16.svg",
532                        "Left Test Panel".to_string(),
533                        left_panel.clone(),
534                        cx,
535                    );
536                });
537
538                let right_panel = cx.add_view(|_| TestItem::new());
539                workspace.right_sidebar().update(cx, |sidebar, cx| {
540                    sidebar.add_item(
541                        "icons/folder_tree_16.svg",
542                        "Right Test Panel".to_string(),
543                        right_panel.clone(),
544                        cx,
545                    );
546                });
547            });
548
549            Self {
550                cx,
551                window_id,
552                workspace,
553            }
554        }
555
556        pub fn workspace<F, T>(&self, read: F) -> T
557        where
558            F: FnOnce(&Workspace, &AppContext) -> T,
559        {
560            self.workspace.read_with(self.cx, read)
561        }
562
563        pub fn update_workspace<F, T>(&mut self, update: F) -> T
564        where
565            F: FnOnce(&mut Workspace, &mut ViewContext<Workspace>) -> T,
566        {
567            self.workspace.update(self.cx, update)
568        }
569
570        pub fn sidebar<F, T>(&self, sidebar_side: SidebarSide, read: F) -> T
571        where
572            F: FnOnce(&Sidebar, &AppContext) -> T,
573        {
574            self.workspace(|workspace, cx| {
575                let sidebar = match sidebar_side {
576                    SidebarSide::Left => workspace.left_sidebar(),
577                    SidebarSide::Right => workspace.right_sidebar(),
578                }
579                .read(cx);
580
581                read(sidebar, cx)
582            })
583        }
584
585        pub fn center_pane_handle(&self) -> ViewHandle<Pane> {
586            self.workspace(|workspace, _| {
587                workspace
588                    .last_active_center_pane
589                    .clone()
590                    .unwrap_or_else(|| workspace.center.panes()[0].clone())
591            })
592        }
593
594        pub fn add_item_to_center_pane(&mut self) -> ViewHandle<TestItem> {
595            self.update_workspace(|workspace, cx| {
596                let item = cx.add_view(|_| TestItem::new());
597                let pane = workspace
598                    .last_active_center_pane
599                    .clone()
600                    .unwrap_or_else(|| workspace.center.panes()[0].clone());
601                Pane::add_item(
602                    workspace,
603                    &pane,
604                    Box::new(item.clone()),
605                    true,
606                    true,
607                    None,
608                    cx,
609                );
610                item
611            })
612        }
613
614        pub fn dock_pane<F, T>(&self, read: F) -> T
615        where
616            F: FnOnce(&Pane, &AppContext) -> T,
617        {
618            self.workspace(|workspace, cx| {
619                let dock_pane = workspace.dock_pane().read(cx);
620                read(dock_pane, cx)
621            })
622        }
623
624        pub fn move_dock(&self, anchor: DockAnchor) {
625            self.cx.dispatch_action(self.window_id, MoveDock(anchor));
626        }
627
628        pub fn hide_dock(&self) {
629            self.cx.dispatch_action(self.window_id, HideDock);
630        }
631
632        pub fn open_sidebar(&mut self, sidebar_side: SidebarSide) {
633            if !self.sidebar(sidebar_side, |sidebar, _| sidebar.is_open()) {
634                self.update_workspace(|workspace, cx| workspace.toggle_sidebar(sidebar_side, cx));
635            }
636        }
637
638        pub fn close_sidebar(&mut self, sidebar_side: SidebarSide) {
639            if self.sidebar(sidebar_side, |sidebar, _| sidebar.is_open()) {
640                self.update_workspace(|workspace, cx| workspace.toggle_sidebar(sidebar_side, cx));
641            }
642        }
643
644        pub fn dock_items(&self) -> Vec<ViewHandle<TestItem>> {
645            self.dock_pane(|pane, cx| {
646                pane.items()
647                    .map(|item| {
648                        item.act_as::<TestItem>(cx)
649                            .expect("Dock Test Context uses TestItems in the dock")
650                    })
651                    .collect()
652            })
653        }
654
655        pub async fn close_dock_items(&mut self) {
656            self.update_workspace(|workspace, cx| {
657                Pane::close_items(workspace, workspace.dock_pane().clone(), cx, |_| true)
658            })
659            .await
660            .expect("Could not close dock items")
661        }
662
663        pub fn assert_dock_position(&self, expected_position: DockPosition) {
664            self.workspace(|workspace, _| assert_eq!(workspace.dock.position, expected_position));
665        }
666
667        pub fn assert_sidebar_closed(&self, sidebar_side: SidebarSide) {
668            assert!(!self.sidebar(sidebar_side, |sidebar, _| sidebar.is_open()));
669        }
670
671        pub fn assert_workspace_pane_active(&self) {
672            assert!(self
673                .center_pane_handle()
674                .read_with(self.cx, |pane, _| pane.is_active()));
675        }
676
677        pub fn assert_workspace_pane_inactive(&self) {
678            assert!(!self
679                .center_pane_handle()
680                .read_with(self.cx, |pane, _| pane.is_active()));
681        }
682
683        pub fn assert_dock_pane_active(&self) {
684            assert!(self.dock_pane(|pane, _| pane.is_active()))
685        }
686
687        pub fn assert_dock_pane_inactive(&self) {
688            assert!(!self.dock_pane(|pane, _| pane.is_active()))
689        }
690    }
691
692    impl<'a> Deref for DockTestContext<'a> {
693        type Target = gpui::TestAppContext;
694
695        fn deref(&self) -> &Self::Target {
696            self.cx
697        }
698    }
699
700    impl<'a> DerefMut for DockTestContext<'a> {
701        fn deref_mut(&mut self) -> &mut Self::Target {
702            &mut self.cx
703        }
704    }
705
706    impl<'a> UpdateView for DockTestContext<'a> {
707        fn update_view<T, S>(
708            &mut self,
709            handle: &ViewHandle<T>,
710            update: &mut dyn FnMut(&mut T, &mut ViewContext<T>) -> S,
711        ) -> S
712        where
713            T: View,
714        {
715            handle.update(self.cx, update)
716        }
717    }
718}