window.rs

   1use crate::{
   2    elements::AnyRootElement,
   3    geometry::rect::RectF,
   4    json::ToJson,
   5    keymap_matcher::{Binding, Keystroke, MatchResult},
   6    platform::{
   7        self, Appearance, CursorStyle, Event, KeyDownEvent, KeyUpEvent, ModifiersChangedEvent,
   8        MouseButton, MouseMovedEvent, PromptLevel, WindowBounds,
   9    },
  10    scene::{
  11        CursorRegion, MouseClick, MouseDown, MouseDownOut, MouseDrag, MouseEvent, MouseHover,
  12        MouseMove, MouseMoveOut, MouseScrollWheel, MouseUp, MouseUpOut, Scene,
  13    },
  14    text_layout::TextLayoutCache,
  15    util::post_inc,
  16    Action, AnyView, AnyViewHandle, AppContext, BorrowAppContext, BorrowWindowContext, Effect,
  17    Element, Entity, Handle, MouseRegion, MouseRegionId, ParentId, SceneBuilder, Subscription,
  18    View, ViewContext, ViewHandle, WindowInvalidation,
  19};
  20use anyhow::{anyhow, bail, Result};
  21use collections::{HashMap, HashSet};
  22use pathfinder_geometry::vector::{vec2f, Vector2F};
  23use postage::oneshot;
  24use serde_json::json;
  25use smallvec::SmallVec;
  26use sqlez::{
  27    bindable::{Bind, Column, StaticColumnCount},
  28    statement::Statement,
  29};
  30use std::{
  31    any::TypeId,
  32    ops::{Deref, DerefMut, Range},
  33};
  34use util::ResultExt;
  35use uuid::Uuid;
  36
  37use super::Reference;
  38
  39pub struct Window {
  40    pub(crate) root_view: Option<AnyViewHandle>,
  41    pub(crate) focused_view_id: Option<usize>,
  42    pub(crate) is_active: bool,
  43    pub(crate) is_fullscreen: bool,
  44    pub(crate) invalidation: Option<WindowInvalidation>,
  45    pub(crate) platform_window: Box<dyn platform::Window>,
  46    pub(crate) rendered_views: HashMap<usize, Box<dyn AnyRootElement>>,
  47    titlebar_height: f32,
  48    appearance: Appearance,
  49    cursor_regions: Vec<CursorRegion>,
  50    mouse_regions: Vec<(MouseRegion, usize)>,
  51    last_mouse_moved_event: Option<Event>,
  52    pub(crate) hovered_region_ids: HashSet<MouseRegionId>,
  53    pub(crate) clicked_region_ids: HashSet<MouseRegionId>,
  54    pub(crate) clicked_button: Option<MouseButton>,
  55    mouse_position: Vector2F,
  56    text_layout_cache: TextLayoutCache,
  57}
  58
  59impl Window {
  60    pub fn new<V, F>(
  61        window_id: usize,
  62        platform_window: Box<dyn platform::Window>,
  63        cx: &mut AppContext,
  64        build_view: F,
  65    ) -> Self
  66    where
  67        F: FnOnce(&mut ViewContext<V>) -> V,
  68        V: View,
  69    {
  70        let titlebar_height = platform_window.titlebar_height();
  71        let appearance = platform_window.appearance();
  72        let mut window = Self {
  73            root_view: None,
  74            focused_view_id: None,
  75            is_active: false,
  76            invalidation: None,
  77            is_fullscreen: false,
  78            platform_window,
  79            rendered_views: Default::default(),
  80            cursor_regions: Default::default(),
  81            mouse_regions: Default::default(),
  82            text_layout_cache: TextLayoutCache::new(cx.font_system.clone()),
  83            last_mouse_moved_event: None,
  84            hovered_region_ids: Default::default(),
  85            clicked_region_ids: Default::default(),
  86            clicked_button: None,
  87            mouse_position: vec2f(0., 0.),
  88            titlebar_height,
  89            appearance,
  90        };
  91
  92        let mut window_context = WindowContext::mutable(cx, &mut window, window_id);
  93        let root_view = window_context
  94            .build_and_insert_view(ParentId::Root, |cx| Some(build_view(cx)))
  95            .unwrap();
  96        if let Some(mut invalidation) = window_context.window.invalidation.take() {
  97            window_context.invalidate(&mut invalidation, appearance);
  98        }
  99        window.focused_view_id = Some(root_view.id());
 100        window.root_view = Some(root_view.into_any());
 101        window
 102    }
 103
 104    pub fn root_view(&self) -> &AnyViewHandle {
 105        &self
 106            .root_view
 107            .as_ref()
 108            .expect("root_view called during window construction")
 109    }
 110}
 111
 112pub struct WindowContext<'a> {
 113    pub(crate) app_context: Reference<'a, AppContext>,
 114    pub(crate) window: Reference<'a, Window>,
 115    pub(crate) window_id: usize,
 116    pub(crate) refreshing: bool,
 117    pub(crate) removed: bool,
 118}
 119
 120impl Deref for WindowContext<'_> {
 121    type Target = AppContext;
 122
 123    fn deref(&self) -> &Self::Target {
 124        &self.app_context
 125    }
 126}
 127
 128impl DerefMut for WindowContext<'_> {
 129    fn deref_mut(&mut self) -> &mut Self::Target {
 130        &mut self.app_context
 131    }
 132}
 133
 134impl BorrowAppContext for WindowContext<'_> {
 135    fn read_with<T, F: FnOnce(&AppContext) -> T>(&self, f: F) -> T {
 136        self.app_context.read_with(f)
 137    }
 138
 139    fn update<T, F: FnOnce(&mut AppContext) -> T>(&mut self, f: F) -> T {
 140        self.app_context.update(f)
 141    }
 142}
 143
 144impl BorrowWindowContext for WindowContext<'_> {
 145    fn read_with<T, F: FnOnce(&WindowContext) -> T>(&self, window_id: usize, f: F) -> T {
 146        if self.window_id == window_id {
 147            f(self)
 148        } else {
 149            panic!("read_with called with id of window that does not belong to this context")
 150        }
 151    }
 152
 153    fn update<T, F: FnOnce(&mut WindowContext) -> T>(&mut self, window_id: usize, f: F) -> T {
 154        if self.window_id == window_id {
 155            f(self)
 156        } else {
 157            panic!("update called with id of window that does not belong to this context")
 158        }
 159    }
 160}
 161
 162impl<'a> WindowContext<'a> {
 163    pub fn mutable(
 164        app_context: &'a mut AppContext,
 165        window: &'a mut Window,
 166        window_id: usize,
 167    ) -> Self {
 168        Self {
 169            app_context: Reference::Mutable(app_context),
 170            window: Reference::Mutable(window),
 171            window_id,
 172            refreshing: false,
 173            removed: false,
 174        }
 175    }
 176
 177    pub fn immutable(app_context: &'a AppContext, window: &'a Window, window_id: usize) -> Self {
 178        Self {
 179            app_context: Reference::Immutable(app_context),
 180            window: Reference::Immutable(window),
 181            window_id,
 182            refreshing: false,
 183            removed: false,
 184        }
 185    }
 186
 187    pub fn remove_window(&mut self) {
 188        self.removed = true;
 189    }
 190
 191    pub fn window_id(&self) -> usize {
 192        self.window_id
 193    }
 194
 195    pub fn app_context(&mut self) -> &mut AppContext {
 196        &mut self.app_context
 197    }
 198
 199    pub fn root_view(&self) -> &AnyViewHandle {
 200        self.window.root_view()
 201    }
 202
 203    pub fn window_size(&self) -> Vector2F {
 204        self.window.platform_window.content_size()
 205    }
 206
 207    pub fn text_layout_cache(&self) -> &TextLayoutCache {
 208        &self.window.text_layout_cache
 209    }
 210
 211    pub(crate) fn update_any_view<F, T>(&mut self, view_id: usize, f: F) -> Option<T>
 212    where
 213        F: FnOnce(&mut dyn AnyView, &mut Self) -> T,
 214    {
 215        let window_id = self.window_id;
 216        let mut view = self.views.remove(&(window_id, view_id))?;
 217        let result = f(view.as_mut(), self);
 218        self.views.insert((window_id, view_id), view);
 219        Some(result)
 220    }
 221
 222    pub(crate) fn update_view<T, S>(
 223        &mut self,
 224        handle: &ViewHandle<T>,
 225        update: &mut dyn FnMut(&mut T, &mut ViewContext<T>) -> S,
 226    ) -> S
 227    where
 228        T: View,
 229    {
 230        self.update_any_view(handle.view_id, |view, cx| {
 231            let mut cx = ViewContext::mutable(cx, handle.view_id);
 232            update(
 233                view.as_any_mut()
 234                    .downcast_mut()
 235                    .expect("downcast is type safe"),
 236                &mut cx,
 237            )
 238        })
 239        .expect("view is already on the stack")
 240    }
 241
 242    pub fn defer(&mut self, callback: impl 'static + FnOnce(&mut WindowContext)) {
 243        let window_id = self.window_id;
 244        self.app_context.defer(move |cx| {
 245            cx.update_window(window_id, |cx| callback(cx));
 246        })
 247    }
 248
 249    pub fn update_global<T, F, U>(&mut self, update: F) -> U
 250    where
 251        T: 'static,
 252        F: FnOnce(&mut T, &mut Self) -> U,
 253    {
 254        AppContext::update_global_internal(self, |global, cx| update(global, cx))
 255    }
 256
 257    pub fn update_default_global<T, F, U>(&mut self, update: F) -> U
 258    where
 259        T: 'static + Default,
 260        F: FnOnce(&mut T, &mut Self) -> U,
 261    {
 262        AppContext::update_default_global_internal(self, |global, cx| update(global, cx))
 263    }
 264
 265    pub fn subscribe<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
 266    where
 267        E: Entity,
 268        E::Event: 'static,
 269        H: Handle<E>,
 270        F: 'static + FnMut(H, &E::Event, &mut WindowContext),
 271    {
 272        self.subscribe_internal(handle, move |emitter, event, cx| {
 273            callback(emitter, event, cx);
 274            true
 275        })
 276    }
 277
 278    pub fn subscribe_internal<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
 279    where
 280        E: Entity,
 281        E::Event: 'static,
 282        H: Handle<E>,
 283        F: 'static + FnMut(H, &E::Event, &mut WindowContext) -> bool,
 284    {
 285        let window_id = self.window_id;
 286        self.app_context
 287            .subscribe_internal(handle, move |emitter, event, cx| {
 288                cx.update_window(window_id, |cx| callback(emitter, event, cx))
 289                    .unwrap_or(false)
 290            })
 291    }
 292
 293    pub(crate) fn observe_window_activation<F>(&mut self, callback: F) -> Subscription
 294    where
 295        F: 'static + FnMut(bool, &mut WindowContext) -> bool,
 296    {
 297        let window_id = self.window_id;
 298        let subscription_id = post_inc(&mut self.next_subscription_id);
 299        self.pending_effects
 300            .push_back(Effect::WindowActivationObservation {
 301                window_id,
 302                subscription_id,
 303                callback: Box::new(callback),
 304            });
 305        Subscription::WindowActivationObservation(
 306            self.window_activation_observations
 307                .subscribe(window_id, subscription_id),
 308        )
 309    }
 310
 311    pub(crate) fn observe_fullscreen<F>(&mut self, callback: F) -> Subscription
 312    where
 313        F: 'static + FnMut(bool, &mut WindowContext) -> bool,
 314    {
 315        let window_id = self.window_id;
 316        let subscription_id = post_inc(&mut self.next_subscription_id);
 317        self.pending_effects
 318            .push_back(Effect::WindowFullscreenObservation {
 319                window_id,
 320                subscription_id,
 321                callback: Box::new(callback),
 322            });
 323        Subscription::WindowActivationObservation(
 324            self.window_activation_observations
 325                .subscribe(window_id, subscription_id),
 326        )
 327    }
 328
 329    pub(crate) fn observe_window_bounds<F>(&mut self, callback: F) -> Subscription
 330    where
 331        F: 'static + FnMut(WindowBounds, Uuid, &mut WindowContext) -> bool,
 332    {
 333        let window_id = self.window_id;
 334        let subscription_id = post_inc(&mut self.next_subscription_id);
 335        self.pending_effects
 336            .push_back(Effect::WindowBoundsObservation {
 337                window_id,
 338                subscription_id,
 339                callback: Box::new(callback),
 340            });
 341        Subscription::WindowBoundsObservation(
 342            self.window_bounds_observations
 343                .subscribe(window_id, subscription_id),
 344        )
 345    }
 346
 347    pub fn observe_keystrokes<F>(&mut self, callback: F) -> Subscription
 348    where
 349        F: 'static
 350            + FnMut(&Keystroke, &MatchResult, Option<&Box<dyn Action>>, &mut WindowContext) -> bool,
 351    {
 352        let window_id = self.window_id;
 353        let subscription_id = post_inc(&mut self.next_subscription_id);
 354        self.keystroke_observations
 355            .add_callback(window_id, subscription_id, Box::new(callback));
 356        Subscription::KeystrokeObservation(
 357            self.keystroke_observations
 358                .subscribe(window_id, subscription_id),
 359        )
 360    }
 361
 362    /// Return keystrokes that would dispatch the given action on the given view.
 363    pub(crate) fn keystrokes_for_action(
 364        &mut self,
 365        view_id: usize,
 366        action: &dyn Action,
 367    ) -> Option<SmallVec<[Keystroke; 2]>> {
 368        let window_id = self.window_id;
 369        let mut contexts = Vec::new();
 370        let mut handler_depth = None;
 371        for (i, view_id) in self.ancestors(view_id).enumerate() {
 372            if let Some(view) = self.views.get(&(window_id, view_id)) {
 373                if let Some(actions) = self.actions.get(&view.as_any().type_id()) {
 374                    if actions.contains_key(&action.as_any().type_id()) {
 375                        handler_depth = Some(i);
 376                    }
 377                }
 378                contexts.push(view.keymap_context(self));
 379            }
 380        }
 381
 382        if self.global_actions.contains_key(&action.as_any().type_id()) {
 383            handler_depth = Some(contexts.len())
 384        }
 385
 386        self.keystroke_matcher
 387            .bindings_for_action_type(action.as_any().type_id())
 388            .find_map(|b| {
 389                handler_depth
 390                    .map(|highest_handler| {
 391                        if (0..=highest_handler).any(|depth| b.match_context(&contexts[depth..])) {
 392                            Some(b.keystrokes().into())
 393                        } else {
 394                            None
 395                        }
 396                    })
 397                    .flatten()
 398            })
 399    }
 400
 401    pub fn available_actions(
 402        &self,
 403        view_id: usize,
 404    ) -> impl Iterator<Item = (&'static str, Box<dyn Action>, SmallVec<[&Binding; 1]>)> {
 405        let window_id = self.window_id;
 406        let mut contexts = Vec::new();
 407        let mut handler_depths_by_action_type = HashMap::<TypeId, usize>::default();
 408        for (depth, view_id) in self.ancestors(view_id).enumerate() {
 409            if let Some(view) = self.views.get(&(window_id, view_id)) {
 410                contexts.push(view.keymap_context(self));
 411                let view_type = view.as_any().type_id();
 412                if let Some(actions) = self.actions.get(&view_type) {
 413                    handler_depths_by_action_type.extend(
 414                        actions
 415                            .keys()
 416                            .copied()
 417                            .map(|action_type| (action_type, depth)),
 418                    );
 419                }
 420            } else {
 421                log::error!(
 422                    "view {} not found when computing available actions",
 423                    view_id
 424                );
 425            }
 426        }
 427
 428        handler_depths_by_action_type.extend(
 429            self.global_actions
 430                .keys()
 431                .copied()
 432                .map(|action_type| (action_type, contexts.len())),
 433        );
 434
 435        self.action_deserializers
 436            .iter()
 437            .filter_map(move |(name, (type_id, deserialize))| {
 438                if let Some(action_depth) = handler_depths_by_action_type.get(type_id).copied() {
 439                    Some((
 440                        *name,
 441                        deserialize("{}").ok()?,
 442                        self.keystroke_matcher
 443                            .bindings_for_action_type(*type_id)
 444                            .filter(|b| {
 445                                (0..=action_depth).any(|depth| b.match_context(&contexts[depth..]))
 446                            })
 447                            .collect(),
 448                    ))
 449                } else {
 450                    None
 451                }
 452            })
 453    }
 454
 455    pub fn dispatch_keystroke(&mut self, keystroke: &Keystroke) -> bool {
 456        let window_id = self.window_id;
 457        if let Some(focused_view_id) = self.focused_view_id() {
 458            let dispatch_path = self
 459                .ancestors(focused_view_id)
 460                .filter_map(|view_id| {
 461                    self.views
 462                        .get(&(window_id, view_id))
 463                        .map(|view| (view_id, view.keymap_context(self)))
 464                })
 465                .collect();
 466
 467            let match_result = self
 468                .keystroke_matcher
 469                .push_keystroke(keystroke.clone(), dispatch_path);
 470            let mut handled_by = None;
 471
 472            let keystroke_handled = match &match_result {
 473                MatchResult::None => false,
 474                MatchResult::Pending => true,
 475                MatchResult::Matches(matches) => {
 476                    for (view_id, action) in matches {
 477                        if self.handle_dispatch_action_from_effect(Some(*view_id), action.as_ref())
 478                        {
 479                            self.keystroke_matcher.clear_pending();
 480                            handled_by = Some(action.boxed_clone());
 481                            break;
 482                        }
 483                    }
 484                    handled_by.is_some()
 485                }
 486            };
 487
 488            self.keystroke(
 489                window_id,
 490                keystroke.clone(),
 491                handled_by,
 492                match_result.clone(),
 493            );
 494            keystroke_handled
 495        } else {
 496            self.keystroke(window_id, keystroke.clone(), None, MatchResult::None);
 497            false
 498        }
 499    }
 500
 501    pub fn dispatch_event(&mut self, event: Event, event_reused: bool) -> bool {
 502        let mut mouse_events = SmallVec::<[_; 2]>::new();
 503        let mut notified_views: HashSet<usize> = Default::default();
 504        let window_id = self.window_id;
 505
 506        // 1. Handle platform event. Keyboard events get dispatched immediately, while mouse events
 507        //    get mapped into the mouse-specific MouseEvent type.
 508        //  -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
 509        //  -> Also updates mouse-related state
 510        match &event {
 511            Event::KeyDown(e) => return self.dispatch_key_down(e),
 512
 513            Event::KeyUp(e) => return self.dispatch_key_up(e),
 514
 515            Event::ModifiersChanged(e) => return self.dispatch_modifiers_changed(e),
 516
 517            Event::MouseDown(e) => {
 518                // Click events are weird because they can be fired after a drag event.
 519                // MDN says that browsers handle this by starting from 'the most
 520                // specific ancestor element that contained both [positions]'
 521                // So we need to store the overlapping regions on mouse down.
 522
 523                // If there is already clicked_button stored, don't replace it.
 524                if self.window.clicked_button.is_none() {
 525                    self.window.clicked_region_ids = self
 526                        .window
 527                        .mouse_regions
 528                        .iter()
 529                        .filter_map(|(region, _)| {
 530                            if region.bounds.contains_point(e.position) {
 531                                Some(region.id())
 532                            } else {
 533                                None
 534                            }
 535                        })
 536                        .collect();
 537
 538                    self.window.clicked_button = Some(e.button);
 539                }
 540
 541                mouse_events.push(MouseEvent::Down(MouseDown {
 542                    region: Default::default(),
 543                    platform_event: e.clone(),
 544                }));
 545                mouse_events.push(MouseEvent::DownOut(MouseDownOut {
 546                    region: Default::default(),
 547                    platform_event: e.clone(),
 548                }));
 549            }
 550
 551            Event::MouseUp(e) => {
 552                // NOTE: The order of event pushes is important! MouseUp events MUST be fired
 553                // before click events, and so the MouseUp events need to be pushed before
 554                // MouseClick events.
 555                mouse_events.push(MouseEvent::Up(MouseUp {
 556                    region: Default::default(),
 557                    platform_event: e.clone(),
 558                }));
 559                mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 560                    region: Default::default(),
 561                    platform_event: e.clone(),
 562                }));
 563                mouse_events.push(MouseEvent::Click(MouseClick {
 564                    region: Default::default(),
 565                    platform_event: e.clone(),
 566                }));
 567            }
 568
 569            Event::MouseMoved(
 570                e @ MouseMovedEvent {
 571                    position,
 572                    pressed_button,
 573                    ..
 574                },
 575            ) => {
 576                let mut style_to_assign = CursorStyle::Arrow;
 577                for region in self.window.cursor_regions.iter().rev() {
 578                    if region.bounds.contains_point(*position) {
 579                        style_to_assign = region.style;
 580                        break;
 581                    }
 582                }
 583
 584                if self
 585                    .window
 586                    .platform_window
 587                    .is_topmost_for_position(*position)
 588                {
 589                    self.platform().set_cursor_style(style_to_assign);
 590                }
 591
 592                if !event_reused {
 593                    if pressed_button.is_some() {
 594                        mouse_events.push(MouseEvent::Drag(MouseDrag {
 595                            region: Default::default(),
 596                            prev_mouse_position: self.window.mouse_position,
 597                            platform_event: e.clone(),
 598                        }));
 599                    } else if let Some(clicked_button) = self.window.clicked_button {
 600                        // Mouse up event happened outside the current window. Simulate mouse up button event
 601                        let button_event = e.to_button_event(clicked_button);
 602                        mouse_events.push(MouseEvent::Up(MouseUp {
 603                            region: Default::default(),
 604                            platform_event: button_event.clone(),
 605                        }));
 606                        mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 607                            region: Default::default(),
 608                            platform_event: button_event.clone(),
 609                        }));
 610                        mouse_events.push(MouseEvent::Click(MouseClick {
 611                            region: Default::default(),
 612                            platform_event: button_event.clone(),
 613                        }));
 614                    }
 615
 616                    mouse_events.push(MouseEvent::Move(MouseMove {
 617                        region: Default::default(),
 618                        platform_event: e.clone(),
 619                    }));
 620                }
 621
 622                mouse_events.push(MouseEvent::Hover(MouseHover {
 623                    region: Default::default(),
 624                    platform_event: e.clone(),
 625                    started: false,
 626                }));
 627                mouse_events.push(MouseEvent::MoveOut(MouseMoveOut {
 628                    region: Default::default(),
 629                }));
 630
 631                self.window.last_mouse_moved_event = Some(event.clone());
 632            }
 633
 634            Event::MouseExited(event) => {
 635                // When the platform sends a MouseExited event, synthesize
 636                // a MouseMoved event whose position is outside the window's
 637                // bounds so that hover and cursor state can be updated.
 638                return self.dispatch_event(
 639                    Event::MouseMoved(MouseMovedEvent {
 640                        position: event.position,
 641                        pressed_button: event.pressed_button,
 642                        modifiers: event.modifiers,
 643                    }),
 644                    event_reused,
 645                );
 646            }
 647
 648            Event::ScrollWheel(e) => mouse_events.push(MouseEvent::ScrollWheel(MouseScrollWheel {
 649                region: Default::default(),
 650                platform_event: e.clone(),
 651            })),
 652        }
 653
 654        if let Some(position) = event.position() {
 655            self.window.mouse_position = position;
 656        }
 657
 658        // 2. Dispatch mouse events on regions
 659        let mut any_event_handled = false;
 660        for mut mouse_event in mouse_events {
 661            let mut valid_regions = Vec::new();
 662
 663            // GPUI elements are arranged by z_index but sibling elements can register overlapping
 664            // mouse regions. As such, hover events are only fired on overlapping elements which
 665            // are at the same z-index as the topmost element which overlaps with the mouse.
 666            match &mouse_event {
 667                MouseEvent::Hover(_) => {
 668                    let mut highest_z_index = None;
 669                    let mouse_position = self.window.mouse_position.clone();
 670                    let window = &mut *self.window;
 671                    for (region, z_index) in window.mouse_regions.iter().rev() {
 672                        // Allow mouse regions to appear transparent to hovers
 673                        if !region.hoverable {
 674                            continue;
 675                        }
 676
 677                        let contains_mouse = region.bounds.contains_point(mouse_position);
 678
 679                        if contains_mouse && highest_z_index.is_none() {
 680                            highest_z_index = Some(z_index);
 681                        }
 682
 683                        // This unwrap relies on short circuiting boolean expressions
 684                        // The right side of the && is only executed when contains_mouse
 685                        // is true, and we know above that when contains_mouse is true
 686                        // highest_z_index is set.
 687                        if contains_mouse && z_index == highest_z_index.unwrap() {
 688                            //Ensure that hover entrance events aren't sent twice
 689                            if window.hovered_region_ids.insert(region.id()) {
 690                                valid_regions.push(region.clone());
 691                                if region.notify_on_hover {
 692                                    notified_views.insert(region.id().view_id());
 693                                }
 694                            }
 695                        } else {
 696                            // Ensure that hover exit events aren't sent twice
 697                            if window.hovered_region_ids.remove(&region.id()) {
 698                                valid_regions.push(region.clone());
 699                                if region.notify_on_hover {
 700                                    notified_views.insert(region.id().view_id());
 701                                }
 702                            }
 703                        }
 704                    }
 705                }
 706
 707                MouseEvent::Down(_) | MouseEvent::Up(_) => {
 708                    for (region, _) in self.window.mouse_regions.iter().rev() {
 709                        if region.bounds.contains_point(self.window.mouse_position) {
 710                            valid_regions.push(region.clone());
 711                            if region.notify_on_click {
 712                                notified_views.insert(region.id().view_id());
 713                            }
 714                        }
 715                    }
 716                }
 717
 718                MouseEvent::Click(e) => {
 719                    // Only raise click events if the released button is the same as the one stored
 720                    if self
 721                        .window
 722                        .clicked_button
 723                        .map(|clicked_button| clicked_button == e.button)
 724                        .unwrap_or(false)
 725                    {
 726                        // Clear clicked regions and clicked button
 727                        let clicked_region_ids = std::mem::replace(
 728                            &mut self.window.clicked_region_ids,
 729                            Default::default(),
 730                        );
 731                        self.window.clicked_button = None;
 732
 733                        // Find regions which still overlap with the mouse since the last MouseDown happened
 734                        for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 735                            if clicked_region_ids.contains(&mouse_region.id()) {
 736                                if mouse_region
 737                                    .bounds
 738                                    .contains_point(self.window.mouse_position)
 739                                {
 740                                    valid_regions.push(mouse_region.clone());
 741                                }
 742                            }
 743                        }
 744                    }
 745                }
 746
 747                MouseEvent::Drag(_) => {
 748                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 749                        if self.window.clicked_region_ids.contains(&mouse_region.id()) {
 750                            valid_regions.push(mouse_region.clone());
 751                        }
 752                    }
 753                }
 754
 755                MouseEvent::MoveOut(_) | MouseEvent::UpOut(_) | MouseEvent::DownOut(_) => {
 756                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 757                        // NOT contains
 758                        if !mouse_region
 759                            .bounds
 760                            .contains_point(self.window.mouse_position)
 761                        {
 762                            valid_regions.push(mouse_region.clone());
 763                        }
 764                    }
 765                }
 766
 767                _ => {
 768                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 769                        // Contains
 770                        if mouse_region
 771                            .bounds
 772                            .contains_point(self.window.mouse_position)
 773                        {
 774                            valid_regions.push(mouse_region.clone());
 775                        }
 776                    }
 777                }
 778            }
 779
 780            //3. Fire region events
 781            let hovered_region_ids = self.window.hovered_region_ids.clone();
 782            for valid_region in valid_regions.into_iter() {
 783                let mut handled = false;
 784                mouse_event.set_region(valid_region.bounds);
 785                if let MouseEvent::Hover(e) = &mut mouse_event {
 786                    e.started = hovered_region_ids.contains(&valid_region.id())
 787                }
 788                // Handle Down events if the MouseRegion has a Click or Drag handler. This makes the api more intuitive as you would
 789                // not expect a MouseRegion to be transparent to Down events if it also has a Click handler.
 790                // This behavior can be overridden by adding a Down handler
 791                if let MouseEvent::Down(e) = &mouse_event {
 792                    let has_click = valid_region
 793                        .handlers
 794                        .contains(MouseEvent::click_disc(), Some(e.button));
 795                    let has_drag = valid_region
 796                        .handlers
 797                        .contains(MouseEvent::drag_disc(), Some(e.button));
 798                    let has_down = valid_region
 799                        .handlers
 800                        .contains(MouseEvent::down_disc(), Some(e.button));
 801                    if !has_down && (has_click || has_drag) {
 802                        handled = true;
 803                    }
 804                }
 805
 806                // `event_consumed` should only be true if there are any handlers for this event.
 807                let mut event_consumed = handled;
 808                if let Some(callbacks) = valid_region.handlers.get(&mouse_event.handler_key()) {
 809                    for callback in callbacks {
 810                        handled = true;
 811                        let view_id = valid_region.id().view_id();
 812                        self.update_any_view(view_id, |view, cx| {
 813                            handled = callback(mouse_event.clone(), view.as_any_mut(), cx, view_id);
 814                        });
 815                        event_consumed |= handled;
 816                        any_event_handled |= handled;
 817                    }
 818                }
 819
 820                any_event_handled |= handled;
 821
 822                // For bubbling events, if the event was handled, don't continue dispatching.
 823                // This only makes sense for local events which return false from is_capturable.
 824                if event_consumed && mouse_event.is_capturable() {
 825                    break;
 826                }
 827            }
 828        }
 829
 830        for view_id in notified_views {
 831            self.notify_view(window_id, view_id);
 832        }
 833
 834        any_event_handled
 835    }
 836
 837    pub fn dispatch_key_down(&mut self, event: &KeyDownEvent) -> bool {
 838        let window_id = self.window_id;
 839        if let Some(focused_view_id) = self.window.focused_view_id {
 840            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 841                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 842                    let handled = view.key_down(event, self, view_id);
 843                    self.views.insert((window_id, view_id), view);
 844                    if handled {
 845                        return true;
 846                    }
 847                } else {
 848                    log::error!("view {} does not exist", view_id)
 849                }
 850            }
 851        }
 852
 853        false
 854    }
 855
 856    pub fn dispatch_key_up(&mut self, event: &KeyUpEvent) -> bool {
 857        let window_id = self.window_id;
 858        if let Some(focused_view_id) = self.window.focused_view_id {
 859            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 860                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 861                    let handled = view.key_up(event, self, view_id);
 862                    self.views.insert((window_id, view_id), view);
 863                    if handled {
 864                        return true;
 865                    }
 866                } else {
 867                    log::error!("view {} does not exist", view_id)
 868                }
 869            }
 870        }
 871
 872        false
 873    }
 874
 875    pub fn dispatch_modifiers_changed(&mut self, event: &ModifiersChangedEvent) -> bool {
 876        let window_id = self.window_id;
 877        if let Some(focused_view_id) = self.window.focused_view_id {
 878            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 879                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 880                    let handled = view.modifiers_changed(event, self, view_id);
 881                    self.views.insert((window_id, view_id), view);
 882                    if handled {
 883                        return true;
 884                    }
 885                } else {
 886                    log::error!("view {} does not exist", view_id)
 887                }
 888            }
 889        }
 890
 891        false
 892    }
 893
 894    pub fn invalidate(&mut self, invalidation: &mut WindowInvalidation, appearance: Appearance) {
 895        self.start_frame();
 896        self.window.appearance = appearance;
 897        for view_id in &invalidation.removed {
 898            invalidation.updated.remove(view_id);
 899            self.window.rendered_views.remove(view_id);
 900        }
 901        for view_id in &invalidation.updated {
 902            let titlebar_height = self.window.titlebar_height;
 903            let hovered_region_ids = self.window.hovered_region_ids.clone();
 904            let clicked_region_ids = self
 905                .window
 906                .clicked_button
 907                .map(|button| (self.window.clicked_region_ids.clone(), button));
 908
 909            let element = self
 910                .render_view(RenderParams {
 911                    view_id: *view_id,
 912                    titlebar_height,
 913                    hovered_region_ids,
 914                    clicked_region_ids,
 915                    refreshing: false,
 916                    appearance,
 917                })
 918                .unwrap();
 919            self.window.rendered_views.insert(*view_id, element);
 920        }
 921    }
 922
 923    pub fn render_view(&mut self, params: RenderParams) -> Result<Box<dyn AnyRootElement>> {
 924        let window_id = self.window_id;
 925        let view_id = params.view_id;
 926        let mut view = self
 927            .views
 928            .remove(&(window_id, view_id))
 929            .ok_or_else(|| anyhow!("view not found"))?;
 930        let element = view.render(self, view_id);
 931        self.views.insert((window_id, view_id), view);
 932        Ok(element)
 933    }
 934
 935    pub fn build_scene(&mut self) -> Result<Scene> {
 936        let window_size = self.window.platform_window.content_size();
 937        let scale_factor = self.window.platform_window.scale_factor();
 938
 939        let root_view_id = self.window.root_view().id();
 940        let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
 941        rendered_root.layout(SizeConstraint::strict(window_size), self)?;
 942
 943        let mut scene_builder = SceneBuilder::new(scale_factor);
 944        rendered_root.paint(
 945            &mut scene_builder,
 946            Vector2F::zero(),
 947            RectF::from_points(Vector2F::zero(), window_size),
 948            self,
 949        )?;
 950        self.window
 951            .rendered_views
 952            .insert(root_view_id, rendered_root);
 953
 954        self.window.text_layout_cache.finish_frame();
 955        let scene = scene_builder.build();
 956        self.window.cursor_regions = scene.cursor_regions();
 957        self.window.mouse_regions = scene.mouse_regions();
 958
 959        if self.window_is_active() {
 960            if let Some(event) = self.window.last_mouse_moved_event.clone() {
 961                self.dispatch_event(event, true);
 962            }
 963        }
 964
 965        Ok(scene)
 966    }
 967
 968    pub fn rect_for_text_range(&self, range_utf16: Range<usize>) -> Option<RectF> {
 969        let root_view_id = self.window.root_view().id();
 970        self.window
 971            .rendered_views
 972            .get(&root_view_id)?
 973            .rect_for_text_range(range_utf16, self)
 974            .log_err()
 975            .flatten()
 976    }
 977
 978    pub fn set_window_title(&mut self, title: &str) {
 979        self.window.platform_window.set_title(title);
 980    }
 981
 982    pub fn set_window_edited(&mut self, edited: bool) {
 983        self.window.platform_window.set_edited(edited);
 984    }
 985
 986    pub fn is_topmost_window_for_position(&self, position: Vector2F) -> bool {
 987        self.window
 988            .platform_window
 989            .is_topmost_for_position(position)
 990    }
 991
 992    pub fn activate_window(&self) {
 993        self.window.platform_window.activate();
 994    }
 995
 996    pub fn window_is_active(&self) -> bool {
 997        self.window.is_active
 998    }
 999
1000    pub fn window_is_fullscreen(&self) -> bool {
1001        self.window.is_fullscreen
1002    }
1003
1004    pub(crate) fn handle_dispatch_action_from_effect(
1005        &mut self,
1006        view_id: Option<usize>,
1007        action: &dyn Action,
1008    ) -> bool {
1009        if let Some(view_id) = view_id {
1010            self.halt_action_dispatch = false;
1011            self.visit_dispatch_path(view_id, |view_id, capture_phase, cx| {
1012                cx.update_any_view(view_id, |view, cx| {
1013                    let type_id = view.as_any().type_id();
1014                    if let Some((name, mut handlers)) = cx
1015                        .actions_mut(capture_phase)
1016                        .get_mut(&type_id)
1017                        .and_then(|h| h.remove_entry(&action.id()))
1018                    {
1019                        for handler in handlers.iter_mut().rev() {
1020                            cx.halt_action_dispatch = true;
1021                            handler(view, action, cx, view_id);
1022                            if cx.halt_action_dispatch {
1023                                break;
1024                            }
1025                        }
1026                        cx.actions_mut(capture_phase)
1027                            .get_mut(&type_id)
1028                            .unwrap()
1029                            .insert(name, handlers);
1030                    }
1031                });
1032
1033                !cx.halt_action_dispatch
1034            });
1035        }
1036
1037        if !self.halt_action_dispatch {
1038            self.halt_action_dispatch = self.dispatch_global_action_any(action);
1039        }
1040
1041        self.pending_effects
1042            .push_back(Effect::ActionDispatchNotification {
1043                action_id: action.id(),
1044            });
1045        self.halt_action_dispatch
1046    }
1047
1048    /// Returns an iterator over all of the view ids from the passed view up to the root of the window
1049    /// Includes the passed view itself
1050    pub(crate) fn ancestors(&self, mut view_id: usize) -> impl Iterator<Item = usize> + '_ {
1051        std::iter::once(view_id)
1052            .into_iter()
1053            .chain(std::iter::from_fn(move || {
1054                if let Some(ParentId::View(parent_id)) =
1055                    self.parents.get(&(self.window_id, view_id))
1056                {
1057                    view_id = *parent_id;
1058                    Some(view_id)
1059                } else {
1060                    None
1061                }
1062            }))
1063    }
1064
1065    /// Returns the id of the parent of the given view, or none if the given
1066    /// view is the root.
1067    pub(crate) fn parent(&self, view_id: usize) -> Option<usize> {
1068        if let Some(ParentId::View(view_id)) = self.parents.get(&(self.window_id, view_id)) {
1069            Some(*view_id)
1070        } else {
1071            None
1072        }
1073    }
1074
1075    // Traverses the parent tree. Walks down the tree toward the passed
1076    // view calling visit with true. Then walks back up the tree calling visit with false.
1077    // If `visit` returns false this function will immediately return.
1078    fn visit_dispatch_path(
1079        &mut self,
1080        view_id: usize,
1081        mut visit: impl FnMut(usize, bool, &mut WindowContext) -> bool,
1082    ) {
1083        // List of view ids from the leaf to the root of the window
1084        let path = self.ancestors(view_id).collect::<Vec<_>>();
1085
1086        // Walk down from the root to the leaf calling visit with capture_phase = true
1087        for view_id in path.iter().rev() {
1088            if !visit(*view_id, true, self) {
1089                return;
1090            }
1091        }
1092
1093        // Walk up from the leaf to the root calling visit with capture_phase = false
1094        for view_id in path.iter() {
1095            if !visit(*view_id, false, self) {
1096                return;
1097            }
1098        }
1099    }
1100
1101    pub fn focused_view_id(&self) -> Option<usize> {
1102        self.window.focused_view_id
1103    }
1104
1105    pub fn is_child_focused(&self, view: &AnyViewHandle) -> bool {
1106        if let Some(focused_view_id) = self.focused_view_id() {
1107            self.ancestors(focused_view_id)
1108                .skip(1) // Skip self id
1109                .any(|parent| parent == view.view_id)
1110        } else {
1111            false
1112        }
1113    }
1114
1115    pub fn window_bounds(&self) -> WindowBounds {
1116        self.window.platform_window.bounds()
1117    }
1118
1119    pub fn window_appearance(&self) -> Appearance {
1120        self.window.appearance
1121    }
1122
1123    pub fn window_display_uuid(&self) -> Option<Uuid> {
1124        self.window.platform_window.screen().display_uuid()
1125    }
1126
1127    pub fn show_character_palette(&self) {
1128        self.window.platform_window.show_character_palette();
1129    }
1130
1131    pub fn minimize_window(&self) {
1132        self.window.platform_window.minimize();
1133    }
1134
1135    pub fn zoom_window(&self) {
1136        self.window.platform_window.zoom();
1137    }
1138
1139    pub fn toggle_full_screen(&self) {
1140        self.window.platform_window.toggle_full_screen();
1141    }
1142
1143    pub fn prompt(
1144        &self,
1145        level: PromptLevel,
1146        msg: &str,
1147        answers: &[&str],
1148    ) -> oneshot::Receiver<usize> {
1149        self.window.platform_window.prompt(level, msg, answers)
1150    }
1151
1152    pub fn replace_root_view<V, F>(&mut self, build_root_view: F) -> ViewHandle<V>
1153    where
1154        V: View,
1155        F: FnOnce(&mut ViewContext<V>) -> V,
1156    {
1157        let root_view = self
1158            .build_and_insert_view(ParentId::Root, |cx| Some(build_root_view(cx)))
1159            .unwrap();
1160        self.window.root_view = Some(root_view.clone().into_any());
1161        self.window.focused_view_id = Some(root_view.id());
1162        root_view
1163    }
1164
1165    pub(crate) fn build_and_insert_view<T, F>(
1166        &mut self,
1167        parent_id: ParentId,
1168        build_view: F,
1169    ) -> Option<ViewHandle<T>>
1170    where
1171        T: View,
1172        F: FnOnce(&mut ViewContext<T>) -> Option<T>,
1173    {
1174        let window_id = self.window_id;
1175        let view_id = post_inc(&mut self.next_entity_id);
1176        // Make sure we can tell child views about their parentu
1177        self.parents.insert((window_id, view_id), parent_id);
1178        let mut cx = ViewContext::mutable(self, view_id);
1179        let handle = if let Some(view) = build_view(&mut cx) {
1180            self.views.insert((window_id, view_id), Box::new(view));
1181            self.window
1182                .invalidation
1183                .get_or_insert_with(Default::default)
1184                .updated
1185                .insert(view_id);
1186            Some(ViewHandle::new(window_id, view_id, &self.ref_counts))
1187        } else {
1188            self.parents.remove(&(window_id, view_id));
1189            None
1190        };
1191        handle
1192    }
1193}
1194
1195pub struct RenderParams {
1196    pub view_id: usize,
1197    pub titlebar_height: f32,
1198    pub hovered_region_ids: HashSet<MouseRegionId>,
1199    pub clicked_region_ids: Option<(HashSet<MouseRegionId>, MouseButton)>,
1200    pub refreshing: bool,
1201    pub appearance: Appearance,
1202}
1203
1204#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
1205pub enum Axis {
1206    #[default]
1207    Horizontal,
1208    Vertical,
1209}
1210
1211impl Axis {
1212    pub fn invert(self) -> Self {
1213        match self {
1214            Self::Horizontal => Self::Vertical,
1215            Self::Vertical => Self::Horizontal,
1216        }
1217    }
1218
1219    pub fn component(&self, point: Vector2F) -> f32 {
1220        match self {
1221            Self::Horizontal => point.x(),
1222            Self::Vertical => point.y(),
1223        }
1224    }
1225}
1226
1227impl ToJson for Axis {
1228    fn to_json(&self) -> serde_json::Value {
1229        match self {
1230            Axis::Horizontal => json!("horizontal"),
1231            Axis::Vertical => json!("vertical"),
1232        }
1233    }
1234}
1235
1236impl StaticColumnCount for Axis {}
1237impl Bind for Axis {
1238    fn bind(&self, statement: &Statement, start_index: i32) -> anyhow::Result<i32> {
1239        match self {
1240            Axis::Horizontal => "Horizontal",
1241            Axis::Vertical => "Vertical",
1242        }
1243        .bind(statement, start_index)
1244    }
1245}
1246
1247impl Column for Axis {
1248    fn column(statement: &mut Statement, start_index: i32) -> anyhow::Result<(Self, i32)> {
1249        String::column(statement, start_index).and_then(|(axis_text, next_index)| {
1250            Ok((
1251                match axis_text.as_str() {
1252                    "Horizontal" => Axis::Horizontal,
1253                    "Vertical" => Axis::Vertical,
1254                    _ => bail!("Stored serialized item kind is incorrect"),
1255                },
1256                next_index,
1257            ))
1258        })
1259    }
1260}
1261
1262pub trait Vector2FExt {
1263    fn along(self, axis: Axis) -> f32;
1264}
1265
1266impl Vector2FExt for Vector2F {
1267    fn along(self, axis: Axis) -> f32 {
1268        match axis {
1269            Axis::Horizontal => self.x(),
1270            Axis::Vertical => self.y(),
1271        }
1272    }
1273}
1274
1275#[derive(Copy, Clone, Debug)]
1276pub struct SizeConstraint {
1277    pub min: Vector2F,
1278    pub max: Vector2F,
1279}
1280
1281impl SizeConstraint {
1282    pub fn new(min: Vector2F, max: Vector2F) -> Self {
1283        Self { min, max }
1284    }
1285
1286    pub fn strict(size: Vector2F) -> Self {
1287        Self {
1288            min: size,
1289            max: size,
1290        }
1291    }
1292
1293    pub fn strict_along(axis: Axis, max: f32) -> Self {
1294        match axis {
1295            Axis::Horizontal => Self {
1296                min: vec2f(max, 0.0),
1297                max: vec2f(max, f32::INFINITY),
1298            },
1299            Axis::Vertical => Self {
1300                min: vec2f(0.0, max),
1301                max: vec2f(f32::INFINITY, max),
1302            },
1303        }
1304    }
1305
1306    pub fn max_along(&self, axis: Axis) -> f32 {
1307        match axis {
1308            Axis::Horizontal => self.max.x(),
1309            Axis::Vertical => self.max.y(),
1310        }
1311    }
1312
1313    pub fn min_along(&self, axis: Axis) -> f32 {
1314        match axis {
1315            Axis::Horizontal => self.min.x(),
1316            Axis::Vertical => self.min.y(),
1317        }
1318    }
1319
1320    pub fn constrain(&self, size: Vector2F) -> Vector2F {
1321        vec2f(
1322            size.x().min(self.max.x()).max(self.min.x()),
1323            size.y().min(self.max.y()).max(self.min.y()),
1324        )
1325    }
1326}
1327
1328impl Default for SizeConstraint {
1329    fn default() -> Self {
1330        SizeConstraint {
1331            min: Vector2F::zero(),
1332            max: Vector2F::splat(f32::INFINITY),
1333        }
1334    }
1335}
1336
1337impl ToJson for SizeConstraint {
1338    fn to_json(&self) -> serde_json::Value {
1339        json!({
1340            "min": self.min.to_json(),
1341            "max": self.max.to_json(),
1342        })
1343    }
1344}
1345
1346pub struct ChildView {
1347    view_id: usize,
1348    view_name: &'static str,
1349}
1350
1351impl ChildView {
1352    pub fn new(view: &AnyViewHandle, cx: &AppContext) -> Self {
1353        let view_name = cx.view_ui_name(view.window_id(), view.id()).unwrap();
1354        Self {
1355            view_id: view.id(),
1356            view_name,
1357        }
1358    }
1359}
1360
1361impl<V: View> Element<V> for ChildView {
1362    type LayoutState = ();
1363    type PaintState = ();
1364
1365    fn layout(
1366        &mut self,
1367        constraint: SizeConstraint,
1368        _: &mut V,
1369        cx: &mut ViewContext<V>,
1370    ) -> (Vector2F, Self::LayoutState) {
1371        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1372            let size = rendered_view
1373                .layout(constraint, cx)
1374                .log_err()
1375                .unwrap_or(Vector2F::zero());
1376            cx.window.rendered_views.insert(self.view_id, rendered_view);
1377            (size, ())
1378        } else {
1379            log::error!(
1380                "layout called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1381                self.view_id,
1382                self.view_name
1383            );
1384            (Vector2F::zero(), ())
1385        }
1386    }
1387
1388    fn paint(
1389        &mut self,
1390        scene: &mut SceneBuilder,
1391        bounds: RectF,
1392        visible_bounds: RectF,
1393        _: &mut Self::LayoutState,
1394        _: &mut V,
1395        cx: &mut ViewContext<V>,
1396    ) {
1397        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1398            rendered_view
1399                .paint(scene, bounds.origin(), visible_bounds, cx)
1400                .log_err();
1401            cx.window.rendered_views.insert(self.view_id, rendered_view);
1402        } else {
1403            log::error!(
1404                "paint called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1405                self.view_id,
1406                self.view_name
1407            );
1408        }
1409    }
1410
1411    fn rect_for_text_range(
1412        &self,
1413        range_utf16: Range<usize>,
1414        _: RectF,
1415        _: RectF,
1416        _: &Self::LayoutState,
1417        _: &Self::PaintState,
1418        _: &V,
1419        cx: &ViewContext<V>,
1420    ) -> Option<RectF> {
1421        if let Some(rendered_view) = cx.window.rendered_views.get(&self.view_id) {
1422            rendered_view
1423                .rect_for_text_range(range_utf16, &cx.window_context)
1424                .log_err()
1425                .flatten()
1426        } else {
1427            log::error!(
1428                "rect_for_text_range called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1429                self.view_id,
1430                self.view_name
1431            );
1432            None
1433        }
1434    }
1435
1436    fn debug(
1437        &self,
1438        bounds: RectF,
1439        _: &Self::LayoutState,
1440        _: &Self::PaintState,
1441        _: &V,
1442        cx: &ViewContext<V>,
1443    ) -> serde_json::Value {
1444        json!({
1445            "type": "ChildView",
1446            "bounds": bounds.to_json(),
1447            "child": if let Some(element) = cx.window.rendered_views.get(&self.view_id) {
1448                element.debug(&cx.window_context).log_err().unwrap_or_else(|| json!(null))
1449            } else {
1450                json!(null)
1451            }
1452        })
1453    }
1454}