window.rs

   1use crate::{
   2    elements::AnyRootElement,
   3    geometry::rect::RectF,
   4    json::ToJson,
   5    keymap_matcher::{Binding, KeymapContext, Keystroke, MatchResult},
   6    platform::{
   7        self, Appearance, CursorStyle, Event, KeyDownEvent, KeyUpEvent, ModifiersChangedEvent,
   8        MouseButton, MouseMovedEvent, PromptLevel, WindowBounds,
   9    },
  10    scene::{
  11        CursorRegion, MouseClick, MouseClickOut, MouseDown, MouseDownOut, MouseDrag, MouseEvent,
  12        MouseHover, 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, LayoutContext, MouseRegion, MouseRegionId, 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    mem,
  33    ops::{Deref, DerefMut, Range},
  34};
  35use util::ResultExt;
  36use uuid::Uuid;
  37
  38use super::{Reference, ViewMetadata};
  39
  40pub struct Window {
  41    pub(crate) root_view: Option<AnyViewHandle>,
  42    pub(crate) focused_view_id: Option<usize>,
  43    pub(crate) parents: HashMap<usize, usize>,
  44    pub(crate) is_active: bool,
  45    pub(crate) is_fullscreen: bool,
  46    pub(crate) invalidation: Option<WindowInvalidation>,
  47    pub(crate) platform_window: Box<dyn platform::Window>,
  48    pub(crate) rendered_views: HashMap<usize, Box<dyn AnyRootElement>>,
  49    titlebar_height: f32,
  50    appearance: Appearance,
  51    cursor_regions: Vec<CursorRegion>,
  52    mouse_regions: Vec<(MouseRegion, usize)>,
  53    last_mouse_moved_event: Option<Event>,
  54    pub(crate) hovered_region_ids: HashSet<MouseRegionId>,
  55    pub(crate) clicked_region_ids: HashSet<MouseRegionId>,
  56    pub(crate) clicked_region: Option<(MouseRegionId, MouseButton)>,
  57    mouse_position: Vector2F,
  58    text_layout_cache: TextLayoutCache,
  59}
  60
  61impl Window {
  62    pub fn new<V, F>(
  63        window_id: usize,
  64        platform_window: Box<dyn platform::Window>,
  65        cx: &mut AppContext,
  66        build_view: F,
  67    ) -> Self
  68    where
  69        F: FnOnce(&mut ViewContext<V>) -> V,
  70        V: View,
  71    {
  72        let titlebar_height = platform_window.titlebar_height();
  73        let appearance = platform_window.appearance();
  74        let mut window = Self {
  75            root_view: None,
  76            focused_view_id: None,
  77            parents: Default::default(),
  78            is_active: false,
  79            invalidation: None,
  80            is_fullscreen: false,
  81            platform_window,
  82            rendered_views: Default::default(),
  83            cursor_regions: Default::default(),
  84            mouse_regions: Default::default(),
  85            text_layout_cache: TextLayoutCache::new(cx.font_system.clone()),
  86            last_mouse_moved_event: None,
  87            hovered_region_ids: Default::default(),
  88            clicked_region_ids: Default::default(),
  89            clicked_region: None,
  90            mouse_position: vec2f(0., 0.),
  91            titlebar_height,
  92            appearance,
  93        };
  94
  95        let mut window_context = WindowContext::mutable(cx, &mut window, window_id);
  96        let root_view = window_context.add_view(|cx| build_view(cx));
  97        if let Some(invalidation) = window_context.window.invalidation.take() {
  98            window_context.invalidate(invalidation, appearance);
  99        }
 100        window.focused_view_id = Some(root_view.id());
 101        window.root_view = Some(root_view.into_any());
 102        window
 103    }
 104
 105    pub fn root_view(&self) -> &AnyViewHandle {
 106        &self
 107            .root_view
 108            .as_ref()
 109            .expect("root_view called during window construction")
 110    }
 111}
 112
 113pub struct WindowContext<'a> {
 114    pub(crate) app_context: Reference<'a, AppContext>,
 115    pub(crate) window: Reference<'a, Window>,
 116    pub(crate) window_id: usize,
 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            removed: false,
 173        }
 174    }
 175
 176    pub fn immutable(app_context: &'a AppContext, window: &'a Window, window_id: usize) -> Self {
 177        Self {
 178            app_context: Reference::Immutable(app_context),
 179            window: Reference::Immutable(window),
 180            window_id,
 181            removed: false,
 182        }
 183    }
 184
 185    pub fn remove_window(&mut self) {
 186        self.removed = true;
 187    }
 188
 189    pub fn window_id(&self) -> usize {
 190        self.window_id
 191    }
 192
 193    pub fn app_context(&mut self) -> &mut AppContext {
 194        &mut self.app_context
 195    }
 196
 197    pub fn root_view(&self) -> &AnyViewHandle {
 198        self.window.root_view()
 199    }
 200
 201    pub fn window_size(&self) -> Vector2F {
 202        self.window.platform_window.content_size()
 203    }
 204
 205    pub fn text_layout_cache(&self) -> &TextLayoutCache {
 206        &self.window.text_layout_cache
 207    }
 208
 209    pub(crate) fn update_any_view<F, T>(&mut self, view_id: usize, f: F) -> Option<T>
 210    where
 211        F: FnOnce(&mut dyn AnyView, &mut Self) -> T,
 212    {
 213        let window_id = self.window_id;
 214        let mut view = self.views.remove(&(window_id, view_id))?;
 215        let result = f(view.as_mut(), self);
 216        self.views.insert((window_id, view_id), view);
 217        Some(result)
 218    }
 219
 220    pub(crate) fn update_view<T, S>(
 221        &mut self,
 222        handle: &ViewHandle<T>,
 223        update: &mut dyn FnMut(&mut T, &mut ViewContext<T>) -> S,
 224    ) -> S
 225    where
 226        T: View,
 227    {
 228        self.update_any_view(handle.view_id, |view, cx| {
 229            let mut cx = ViewContext::mutable(cx, handle.view_id);
 230            update(
 231                view.as_any_mut()
 232                    .downcast_mut()
 233                    .expect("downcast is type safe"),
 234                &mut cx,
 235            )
 236        })
 237        .expect("view is already on the stack")
 238    }
 239
 240    pub fn defer(&mut self, callback: impl 'static + FnOnce(&mut WindowContext)) {
 241        let window_id = self.window_id;
 242        self.app_context.defer(move |cx| {
 243            cx.update_window(window_id, |cx| callback(cx));
 244        })
 245    }
 246
 247    pub fn update_global<T, F, U>(&mut self, update: F) -> U
 248    where
 249        T: 'static,
 250        F: FnOnce(&mut T, &mut Self) -> U,
 251    {
 252        AppContext::update_global_internal(self, |global, cx| update(global, cx))
 253    }
 254
 255    pub fn update_default_global<T, F, U>(&mut self, update: F) -> U
 256    where
 257        T: 'static + Default,
 258        F: FnOnce(&mut T, &mut Self) -> U,
 259    {
 260        AppContext::update_default_global_internal(self, |global, cx| update(global, cx))
 261    }
 262
 263    pub fn subscribe<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
 264    where
 265        E: Entity,
 266        E::Event: 'static,
 267        H: Handle<E>,
 268        F: 'static + FnMut(H, &E::Event, &mut WindowContext),
 269    {
 270        self.subscribe_internal(handle, move |emitter, event, cx| {
 271            callback(emitter, event, cx);
 272            true
 273        })
 274    }
 275
 276    pub fn subscribe_internal<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
 277    where
 278        E: Entity,
 279        E::Event: 'static,
 280        H: Handle<E>,
 281        F: 'static + FnMut(H, &E::Event, &mut WindowContext) -> bool,
 282    {
 283        let window_id = self.window_id;
 284        self.app_context
 285            .subscribe_internal(handle, move |emitter, event, cx| {
 286                cx.update_window(window_id, |cx| callback(emitter, event, cx))
 287                    .unwrap_or(false)
 288            })
 289    }
 290
 291    pub(crate) fn observe_window_activation<F>(&mut self, callback: F) -> Subscription
 292    where
 293        F: 'static + FnMut(bool, &mut WindowContext) -> bool,
 294    {
 295        let window_id = self.window_id;
 296        let subscription_id = post_inc(&mut self.next_subscription_id);
 297        self.pending_effects
 298            .push_back(Effect::WindowActivationObservation {
 299                window_id,
 300                subscription_id,
 301                callback: Box::new(callback),
 302            });
 303        Subscription::WindowActivationObservation(
 304            self.window_activation_observations
 305                .subscribe(window_id, subscription_id),
 306        )
 307    }
 308
 309    pub(crate) fn observe_fullscreen<F>(&mut self, callback: F) -> Subscription
 310    where
 311        F: 'static + FnMut(bool, &mut WindowContext) -> bool,
 312    {
 313        let window_id = self.window_id;
 314        let subscription_id = post_inc(&mut self.next_subscription_id);
 315        self.pending_effects
 316            .push_back(Effect::WindowFullscreenObservation {
 317                window_id,
 318                subscription_id,
 319                callback: Box::new(callback),
 320            });
 321        Subscription::WindowActivationObservation(
 322            self.window_activation_observations
 323                .subscribe(window_id, subscription_id),
 324        )
 325    }
 326
 327    pub(crate) fn observe_window_bounds<F>(&mut self, callback: F) -> Subscription
 328    where
 329        F: 'static + FnMut(WindowBounds, Uuid, &mut WindowContext) -> bool,
 330    {
 331        let window_id = self.window_id;
 332        let subscription_id = post_inc(&mut self.next_subscription_id);
 333        self.pending_effects
 334            .push_back(Effect::WindowBoundsObservation {
 335                window_id,
 336                subscription_id,
 337                callback: Box::new(callback),
 338            });
 339        Subscription::WindowBoundsObservation(
 340            self.window_bounds_observations
 341                .subscribe(window_id, subscription_id),
 342        )
 343    }
 344
 345    pub fn observe_keystrokes<F>(&mut self, callback: F) -> Subscription
 346    where
 347        F: 'static
 348            + FnMut(&Keystroke, &MatchResult, Option<&Box<dyn Action>>, &mut WindowContext) -> bool,
 349    {
 350        let window_id = self.window_id;
 351        let subscription_id = post_inc(&mut self.next_subscription_id);
 352        self.keystroke_observations
 353            .add_callback(window_id, subscription_id, Box::new(callback));
 354        Subscription::KeystrokeObservation(
 355            self.keystroke_observations
 356                .subscribe(window_id, subscription_id),
 357        )
 358    }
 359
 360    pub(crate) fn available_actions(
 361        &self,
 362        view_id: usize,
 363    ) -> Vec<(&'static str, Box<dyn Action>, SmallVec<[Binding; 1]>)> {
 364        let window_id = self.window_id;
 365        let mut contexts = Vec::new();
 366        let mut handler_depths_by_action_id = HashMap::<TypeId, usize>::default();
 367        for (depth, view_id) in self.ancestors(view_id).enumerate() {
 368            if let Some(view_metadata) = self.views_metadata.get(&(window_id, view_id)) {
 369                contexts.push(view_metadata.keymap_context.clone());
 370                if let Some(actions) = self.actions.get(&view_metadata.type_id) {
 371                    handler_depths_by_action_id
 372                        .extend(actions.keys().copied().map(|action_id| (action_id, depth)));
 373                }
 374            } else {
 375                log::error!(
 376                    "view {} not found when computing available actions",
 377                    view_id
 378                );
 379            }
 380        }
 381
 382        handler_depths_by_action_id.extend(
 383            self.global_actions
 384                .keys()
 385                .copied()
 386                .map(|action_id| (action_id, contexts.len())),
 387        );
 388
 389        self.action_deserializers
 390            .iter()
 391            .filter_map(move |(name, (action_id, deserialize))| {
 392                if let Some(action_depth) = handler_depths_by_action_id.get(action_id).copied() {
 393                    let action = deserialize(serde_json::Value::Object(Default::default())).ok()?;
 394                    let bindings = self
 395                        .keystroke_matcher
 396                        .bindings_for_action(*action_id)
 397                        .filter(|b| {
 398                            action.eq(b.action())
 399                                && (0..=action_depth)
 400                                    .any(|depth| b.match_context(&contexts[depth..]))
 401                        })
 402                        .cloned()
 403                        .collect();
 404                    Some((*name, action, bindings))
 405                } else {
 406                    None
 407                }
 408            })
 409            .collect()
 410    }
 411
 412    pub(crate) fn dispatch_keystroke(&mut self, keystroke: &Keystroke) -> bool {
 413        let window_id = self.window_id;
 414        if let Some(focused_view_id) = self.focused_view_id() {
 415            let dispatch_path = self
 416                .ancestors(focused_view_id)
 417                .filter_map(|view_id| {
 418                    self.views_metadata
 419                        .get(&(window_id, view_id))
 420                        .map(|view| (view_id, view.keymap_context.clone()))
 421                })
 422                .collect();
 423
 424            let match_result = self
 425                .keystroke_matcher
 426                .push_keystroke(keystroke.clone(), dispatch_path);
 427            let mut handled_by = None;
 428
 429            let keystroke_handled = match &match_result {
 430                MatchResult::None => false,
 431                MatchResult::Pending => true,
 432                MatchResult::Matches(matches) => {
 433                    for (view_id, action) in matches {
 434                        if self.dispatch_action(Some(*view_id), action.as_ref()) {
 435                            self.keystroke_matcher.clear_pending();
 436                            handled_by = Some(action.boxed_clone());
 437                            break;
 438                        }
 439                    }
 440                    handled_by.is_some()
 441                }
 442            };
 443
 444            self.keystroke(
 445                window_id,
 446                keystroke.clone(),
 447                handled_by,
 448                match_result.clone(),
 449            );
 450            keystroke_handled
 451        } else {
 452            self.keystroke(window_id, keystroke.clone(), None, MatchResult::None);
 453            false
 454        }
 455    }
 456
 457    pub(crate) fn dispatch_event(&mut self, event: Event, event_reused: bool) -> bool {
 458        let mut mouse_events = SmallVec::<[_; 2]>::new();
 459        let mut notified_views: HashSet<usize> = Default::default();
 460        let window_id = self.window_id;
 461
 462        // 1. Handle platform event. Keyboard events get dispatched immediately, while mouse events
 463        //    get mapped into the mouse-specific MouseEvent type.
 464        //  -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
 465        //  -> Also updates mouse-related state
 466        match &event {
 467            Event::KeyDown(e) => return self.dispatch_key_down(e),
 468
 469            Event::KeyUp(e) => return self.dispatch_key_up(e),
 470
 471            Event::ModifiersChanged(e) => return self.dispatch_modifiers_changed(e),
 472
 473            Event::MouseDown(e) => {
 474                // Click events are weird because they can be fired after a drag event.
 475                // MDN says that browsers handle this by starting from 'the most
 476                // specific ancestor element that contained both [positions]'
 477                // So we need to store the overlapping regions on mouse down.
 478
 479                // If there is already region being clicked, don't replace it.
 480                if self.window.clicked_region.is_none() {
 481                    self.window.clicked_region_ids = self
 482                        .window
 483                        .mouse_regions
 484                        .iter()
 485                        .filter_map(|(region, _)| {
 486                            if region.bounds.contains_point(e.position) {
 487                                Some(region.id())
 488                            } else {
 489                                None
 490                            }
 491                        })
 492                        .collect();
 493
 494                    let mut highest_z_index = 0;
 495                    let mut clicked_region_id = None;
 496                    for (region, z_index) in self.window.mouse_regions.iter() {
 497                        if region.bounds.contains_point(e.position) && *z_index >= highest_z_index {
 498                            highest_z_index = *z_index;
 499                            clicked_region_id = Some(region.id());
 500                        }
 501                    }
 502
 503                    self.window.clicked_region =
 504                        clicked_region_id.map(|region_id| (region_id, e.button));
 505                }
 506
 507                mouse_events.push(MouseEvent::Down(MouseDown {
 508                    region: Default::default(),
 509                    platform_event: e.clone(),
 510                }));
 511                mouse_events.push(MouseEvent::DownOut(MouseDownOut {
 512                    region: Default::default(),
 513                    platform_event: e.clone(),
 514                }));
 515            }
 516
 517            Event::MouseUp(e) => {
 518                // NOTE: The order of event pushes is important! MouseUp events MUST be fired
 519                // before click events, and so the MouseUp events need to be pushed before
 520                // MouseClick events.
 521
 522                // Synthesize one last drag event to end the drag
 523                mouse_events.push(MouseEvent::Drag(MouseDrag {
 524                    region: Default::default(),
 525                    prev_mouse_position: self.window.mouse_position,
 526                    platform_event: MouseMovedEvent {
 527                        position: e.position,
 528                        pressed_button: Some(e.button),
 529                        modifiers: e.modifiers,
 530                    },
 531                    end: true,
 532                }));
 533                mouse_events.push(MouseEvent::Up(MouseUp {
 534                    region: Default::default(),
 535                    platform_event: e.clone(),
 536                }));
 537                mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 538                    region: Default::default(),
 539                    platform_event: e.clone(),
 540                }));
 541                mouse_events.push(MouseEvent::Click(MouseClick {
 542                    region: Default::default(),
 543                    platform_event: e.clone(),
 544                }));
 545                mouse_events.push(MouseEvent::ClickOut(MouseClickOut {
 546                    region: Default::default(),
 547                    platform_event: e.clone(),
 548                }));
 549            }
 550
 551            Event::MouseMoved(
 552                e @ MouseMovedEvent {
 553                    position,
 554                    pressed_button,
 555                    ..
 556                },
 557            ) => {
 558                let mut style_to_assign = CursorStyle::Arrow;
 559                for region in self.window.cursor_regions.iter().rev() {
 560                    if region.bounds.contains_point(*position) {
 561                        style_to_assign = region.style;
 562                        break;
 563                    }
 564                }
 565
 566                if self
 567                    .window
 568                    .platform_window
 569                    .is_topmost_for_position(*position)
 570                {
 571                    self.platform().set_cursor_style(style_to_assign);
 572                }
 573
 574                if !event_reused {
 575                    if pressed_button.is_some() {
 576                        mouse_events.push(MouseEvent::Drag(MouseDrag {
 577                            region: Default::default(),
 578                            prev_mouse_position: self.window.mouse_position,
 579                            platform_event: e.clone(),
 580                            end: false,
 581                        }));
 582                    } else if let Some((_, clicked_button)) = self.window.clicked_region {
 583                        mouse_events.push(MouseEvent::Drag(MouseDrag {
 584                            region: Default::default(),
 585                            prev_mouse_position: self.window.mouse_position,
 586                            platform_event: e.clone(),
 587                            end: true,
 588                        }));
 589
 590                        // Mouse up event happened outside the current window. Simulate mouse up button event
 591                        let button_event = e.to_button_event(clicked_button);
 592                        mouse_events.push(MouseEvent::Up(MouseUp {
 593                            region: Default::default(),
 594                            platform_event: button_event.clone(),
 595                        }));
 596                        mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 597                            region: Default::default(),
 598                            platform_event: button_event.clone(),
 599                        }));
 600                        mouse_events.push(MouseEvent::Click(MouseClick {
 601                            region: Default::default(),
 602                            platform_event: button_event.clone(),
 603                        }));
 604                    }
 605
 606                    mouse_events.push(MouseEvent::Move(MouseMove {
 607                        region: Default::default(),
 608                        platform_event: e.clone(),
 609                    }));
 610                }
 611
 612                mouse_events.push(MouseEvent::Hover(MouseHover {
 613                    region: Default::default(),
 614                    platform_event: e.clone(),
 615                    started: false,
 616                }));
 617                mouse_events.push(MouseEvent::MoveOut(MouseMoveOut {
 618                    region: Default::default(),
 619                }));
 620
 621                self.window.last_mouse_moved_event = Some(event.clone());
 622            }
 623
 624            Event::MouseExited(event) => {
 625                // When the platform sends a MouseExited event, synthesize
 626                // a MouseMoved event whose position is outside the window's
 627                // bounds so that hover and cursor state can be updated.
 628                return self.dispatch_event(
 629                    Event::MouseMoved(MouseMovedEvent {
 630                        position: event.position,
 631                        pressed_button: event.pressed_button,
 632                        modifiers: event.modifiers,
 633                    }),
 634                    event_reused,
 635                );
 636            }
 637
 638            Event::ScrollWheel(e) => mouse_events.push(MouseEvent::ScrollWheel(MouseScrollWheel {
 639                region: Default::default(),
 640                platform_event: e.clone(),
 641            })),
 642        }
 643
 644        if let Some(position) = event.position() {
 645            self.window.mouse_position = position;
 646        }
 647
 648        // 2. Dispatch mouse events on regions
 649        let mut any_event_handled = false;
 650        for mut mouse_event in mouse_events {
 651            let mut valid_regions = Vec::new();
 652
 653            // GPUI elements are arranged by z_index but sibling elements can register overlapping
 654            // mouse regions. As such, hover events are only fired on overlapping elements which
 655            // are at the same z-index as the topmost element which overlaps with the mouse.
 656            match &mouse_event {
 657                MouseEvent::Hover(_) => {
 658                    let mut highest_z_index = None;
 659                    let mouse_position = self.window.mouse_position.clone();
 660                    let window = &mut *self.window;
 661                    for (region, z_index) in window.mouse_regions.iter().rev() {
 662                        // Allow mouse regions to appear transparent to hovers
 663                        if !region.hoverable {
 664                            continue;
 665                        }
 666
 667                        let contains_mouse = region.bounds.contains_point(mouse_position);
 668
 669                        if contains_mouse && highest_z_index.is_none() {
 670                            highest_z_index = Some(z_index);
 671                        }
 672
 673                        // This unwrap relies on short circuiting boolean expressions
 674                        // The right side of the && is only executed when contains_mouse
 675                        // is true, and we know above that when contains_mouse is true
 676                        // highest_z_index is set.
 677                        if contains_mouse && z_index == highest_z_index.unwrap() {
 678                            //Ensure that hover entrance events aren't sent twice
 679                            if window.hovered_region_ids.insert(region.id()) {
 680                                valid_regions.push(region.clone());
 681                                if region.notify_on_hover {
 682                                    notified_views.insert(region.id().view_id());
 683                                }
 684                            }
 685                        } else {
 686                            // Ensure that hover exit events aren't sent twice
 687                            if window.hovered_region_ids.remove(&region.id()) {
 688                                valid_regions.push(region.clone());
 689                                if region.notify_on_hover {
 690                                    notified_views.insert(region.id().view_id());
 691                                }
 692                            }
 693                        }
 694                    }
 695                }
 696
 697                MouseEvent::Down(_) | MouseEvent::Up(_) => {
 698                    for (region, _) in self.window.mouse_regions.iter().rev() {
 699                        if region.bounds.contains_point(self.window.mouse_position) {
 700                            valid_regions.push(region.clone());
 701                            if region.notify_on_click {
 702                                notified_views.insert(region.id().view_id());
 703                            }
 704                        }
 705                    }
 706                }
 707
 708                MouseEvent::Click(e) => {
 709                    // Only raise click events if the released button is the same as the one stored
 710                    if self
 711                        .window
 712                        .clicked_region
 713                        .map(|(_, clicked_button)| clicked_button == e.button)
 714                        .unwrap_or(false)
 715                    {
 716                        // Clear clicked regions and clicked button
 717                        let clicked_region_ids = std::mem::replace(
 718                            &mut self.window.clicked_region_ids,
 719                            Default::default(),
 720                        );
 721                        self.window.clicked_region = None;
 722
 723                        // Find regions which still overlap with the mouse since the last MouseDown happened
 724                        for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 725                            if clicked_region_ids.contains(&mouse_region.id()) {
 726                                if mouse_region
 727                                    .bounds
 728                                    .contains_point(self.window.mouse_position)
 729                                {
 730                                    valid_regions.push(mouse_region.clone());
 731                                }
 732                            }
 733                        }
 734                    }
 735                }
 736
 737                MouseEvent::Drag(_) => {
 738                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 739                        if self.window.clicked_region_ids.contains(&mouse_region.id()) {
 740                            valid_regions.push(mouse_region.clone());
 741                        }
 742                    }
 743                }
 744
 745                MouseEvent::MoveOut(_)
 746                | MouseEvent::UpOut(_)
 747                | MouseEvent::DownOut(_)
 748                | MouseEvent::ClickOut(_) => {
 749                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 750                        // NOT contains
 751                        if !mouse_region
 752                            .bounds
 753                            .contains_point(self.window.mouse_position)
 754                        {
 755                            valid_regions.push(mouse_region.clone());
 756                        }
 757                    }
 758                }
 759
 760                _ => {
 761                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 762                        // Contains
 763                        if mouse_region
 764                            .bounds
 765                            .contains_point(self.window.mouse_position)
 766                        {
 767                            valid_regions.push(mouse_region.clone());
 768                        }
 769                    }
 770                }
 771            }
 772
 773            //3. Fire region events
 774            let hovered_region_ids = self.window.hovered_region_ids.clone();
 775            for valid_region in valid_regions.into_iter() {
 776                let mut handled = false;
 777                mouse_event.set_region(valid_region.bounds);
 778                if let MouseEvent::Hover(e) = &mut mouse_event {
 779                    e.started = hovered_region_ids.contains(&valid_region.id())
 780                }
 781                // Handle Down events if the MouseRegion has a Click or Drag handler. This makes the api more intuitive as you would
 782                // not expect a MouseRegion to be transparent to Down events if it also has a Click handler.
 783                // This behavior can be overridden by adding a Down handler
 784                if let MouseEvent::Down(e) = &mouse_event {
 785                    let has_click = valid_region
 786                        .handlers
 787                        .contains(MouseEvent::click_disc(), Some(e.button));
 788                    let has_drag = valid_region
 789                        .handlers
 790                        .contains(MouseEvent::drag_disc(), Some(e.button));
 791                    let has_down = valid_region
 792                        .handlers
 793                        .contains(MouseEvent::down_disc(), Some(e.button));
 794                    if !has_down && (has_click || has_drag) {
 795                        handled = true;
 796                    }
 797                }
 798
 799                // `event_consumed` should only be true if there are any handlers for this event.
 800                let mut event_consumed = handled;
 801                if let Some(callbacks) = valid_region.handlers.get(&mouse_event.handler_key()) {
 802                    for callback in callbacks {
 803                        handled = true;
 804                        let view_id = valid_region.id().view_id();
 805                        self.update_any_view(view_id, |view, cx| {
 806                            handled = callback(mouse_event.clone(), view.as_any_mut(), cx, view_id);
 807                        });
 808                        event_consumed |= handled;
 809                        any_event_handled |= handled;
 810                    }
 811                }
 812
 813                any_event_handled |= handled;
 814
 815                // For bubbling events, if the event was handled, don't continue dispatching.
 816                // This only makes sense for local events which return false from is_capturable.
 817                if event_consumed && mouse_event.is_capturable() {
 818                    break;
 819                }
 820            }
 821        }
 822
 823        for view_id in notified_views {
 824            self.notify_view(window_id, view_id);
 825        }
 826
 827        any_event_handled
 828    }
 829
 830    pub(crate) fn dispatch_key_down(&mut self, event: &KeyDownEvent) -> bool {
 831        let window_id = self.window_id;
 832        if let Some(focused_view_id) = self.window.focused_view_id {
 833            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 834                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 835                    let handled = view.key_down(event, self, view_id);
 836                    self.views.insert((window_id, view_id), view);
 837                    if handled {
 838                        return true;
 839                    }
 840                } else {
 841                    log::error!("view {} does not exist", view_id)
 842                }
 843            }
 844        }
 845
 846        false
 847    }
 848
 849    pub(crate) fn dispatch_key_up(&mut self, event: &KeyUpEvent) -> bool {
 850        let window_id = self.window_id;
 851        if let Some(focused_view_id) = self.window.focused_view_id {
 852            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 853                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 854                    let handled = view.key_up(event, self, view_id);
 855                    self.views.insert((window_id, view_id), view);
 856                    if handled {
 857                        return true;
 858                    }
 859                } else {
 860                    log::error!("view {} does not exist", view_id)
 861                }
 862            }
 863        }
 864
 865        false
 866    }
 867
 868    pub(crate) fn dispatch_modifiers_changed(&mut self, event: &ModifiersChangedEvent) -> bool {
 869        let window_id = self.window_id;
 870        if let Some(focused_view_id) = self.window.focused_view_id {
 871            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 872                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 873                    let handled = view.modifiers_changed(event, self, view_id);
 874                    self.views.insert((window_id, view_id), view);
 875                    if handled {
 876                        return true;
 877                    }
 878                } else {
 879                    log::error!("view {} does not exist", view_id)
 880                }
 881            }
 882        }
 883
 884        false
 885    }
 886
 887    pub fn invalidate(&mut self, mut invalidation: WindowInvalidation, appearance: Appearance) {
 888        self.start_frame();
 889        self.window.appearance = appearance;
 890        for view_id in &invalidation.removed {
 891            invalidation.updated.remove(view_id);
 892            self.window.rendered_views.remove(view_id);
 893        }
 894        for view_id in &invalidation.updated {
 895            let titlebar_height = self.window.titlebar_height;
 896            let element = self
 897                .render_view(RenderParams {
 898                    view_id: *view_id,
 899                    titlebar_height,
 900                    refreshing: false,
 901                    appearance,
 902                })
 903                .unwrap();
 904            self.window.rendered_views.insert(*view_id, element);
 905        }
 906    }
 907
 908    pub fn render_view(&mut self, params: RenderParams) -> Result<Box<dyn AnyRootElement>> {
 909        let window_id = self.window_id;
 910        let view_id = params.view_id;
 911        let mut view = self
 912            .views
 913            .remove(&(window_id, view_id))
 914            .ok_or_else(|| anyhow!("view not found"))?;
 915        let element = view.render(self, view_id);
 916        self.views.insert((window_id, view_id), view);
 917        Ok(element)
 918    }
 919
 920    pub(crate) fn layout(&mut self, refreshing: bool) -> Result<HashMap<usize, usize>> {
 921        let window_size = self.window.platform_window.content_size();
 922        let root_view_id = self.window.root_view().id();
 923        let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
 924        let mut new_parents = HashMap::default();
 925        let mut views_to_notify_if_ancestors_change = HashMap::default();
 926        rendered_root.layout(
 927            SizeConstraint::strict(window_size),
 928            &mut new_parents,
 929            &mut views_to_notify_if_ancestors_change,
 930            refreshing,
 931            self,
 932        )?;
 933
 934        for (view_id, view_ids_to_notify) in views_to_notify_if_ancestors_change {
 935            let mut current_view_id = view_id;
 936            loop {
 937                let old_parent_id = self.window.parents.get(&current_view_id);
 938                let new_parent_id = new_parents.get(&current_view_id);
 939                if old_parent_id.is_none() && new_parent_id.is_none() {
 940                    break;
 941                } else if old_parent_id == new_parent_id {
 942                    current_view_id = *old_parent_id.unwrap();
 943                } else {
 944                    let window_id = self.window_id;
 945                    for view_id_to_notify in view_ids_to_notify {
 946                        self.notify_view(window_id, view_id_to_notify);
 947                    }
 948                    break;
 949                }
 950            }
 951        }
 952
 953        let old_parents = mem::replace(&mut self.window.parents, new_parents);
 954        self.window
 955            .rendered_views
 956            .insert(root_view_id, rendered_root);
 957        Ok(old_parents)
 958    }
 959
 960    pub(crate) fn paint(&mut self) -> Result<Scene> {
 961        let window_size = self.window.platform_window.content_size();
 962        let scale_factor = self.window.platform_window.scale_factor();
 963
 964        let root_view_id = self.window.root_view().id();
 965        let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
 966
 967        let mut scene_builder = SceneBuilder::new(scale_factor);
 968        rendered_root.paint(
 969            &mut scene_builder,
 970            Vector2F::zero(),
 971            RectF::from_points(Vector2F::zero(), window_size),
 972            self,
 973        )?;
 974        self.window
 975            .rendered_views
 976            .insert(root_view_id, rendered_root);
 977
 978        self.window.text_layout_cache.finish_frame();
 979        let scene = scene_builder.build();
 980        self.window.cursor_regions = scene.cursor_regions();
 981        self.window.mouse_regions = scene.mouse_regions();
 982
 983        if self.window_is_active() {
 984            if let Some(event) = self.window.last_mouse_moved_event.clone() {
 985                self.dispatch_event(event, true);
 986            }
 987        }
 988
 989        Ok(scene)
 990    }
 991
 992    pub fn rect_for_text_range(&self, range_utf16: Range<usize>) -> Option<RectF> {
 993        let focused_view_id = self.window.focused_view_id?;
 994        self.window
 995            .rendered_views
 996            .get(&focused_view_id)?
 997            .rect_for_text_range(range_utf16, self)
 998            .log_err()
 999            .flatten()
1000    }
1001
1002    pub fn set_window_title(&mut self, title: &str) {
1003        self.window.platform_window.set_title(title);
1004    }
1005
1006    pub fn set_window_edited(&mut self, edited: bool) {
1007        self.window.platform_window.set_edited(edited);
1008    }
1009
1010    pub fn is_topmost_window_for_position(&self, position: Vector2F) -> bool {
1011        self.window
1012            .platform_window
1013            .is_topmost_for_position(position)
1014    }
1015
1016    pub fn activate_window(&self) {
1017        self.window.platform_window.activate();
1018    }
1019
1020    pub fn window_is_active(&self) -> bool {
1021        self.window.is_active
1022    }
1023
1024    pub fn window_is_fullscreen(&self) -> bool {
1025        self.window.is_fullscreen
1026    }
1027
1028    pub(crate) fn dispatch_action(&mut self, view_id: Option<usize>, action: &dyn Action) -> bool {
1029        if let Some(view_id) = view_id {
1030            self.halt_action_dispatch = false;
1031            self.visit_dispatch_path(view_id, |view_id, capture_phase, cx| {
1032                cx.update_any_view(view_id, |view, cx| {
1033                    let type_id = view.as_any().type_id();
1034                    if let Some((name, mut handlers)) = cx
1035                        .actions_mut(capture_phase)
1036                        .get_mut(&type_id)
1037                        .and_then(|h| h.remove_entry(&action.id()))
1038                    {
1039                        for handler in handlers.iter_mut().rev() {
1040                            cx.halt_action_dispatch = true;
1041                            handler(view, action, cx, view_id);
1042                            if cx.halt_action_dispatch {
1043                                break;
1044                            }
1045                        }
1046                        cx.actions_mut(capture_phase)
1047                            .get_mut(&type_id)
1048                            .unwrap()
1049                            .insert(name, handlers);
1050                    }
1051                });
1052
1053                !cx.halt_action_dispatch
1054            });
1055        }
1056
1057        if !self.halt_action_dispatch {
1058            self.halt_action_dispatch = self.dispatch_global_action_any(action);
1059        }
1060
1061        self.pending_effects
1062            .push_back(Effect::ActionDispatchNotification {
1063                action_id: action.id(),
1064            });
1065        self.halt_action_dispatch
1066    }
1067
1068    /// Returns an iterator over all of the view ids from the passed view up to the root of the window
1069    /// Includes the passed view itself
1070    pub(crate) fn ancestors(&self, mut view_id: usize) -> impl Iterator<Item = usize> + '_ {
1071        std::iter::once(view_id)
1072            .into_iter()
1073            .chain(std::iter::from_fn(move || {
1074                if let Some(parent_id) = self.window.parents.get(&view_id) {
1075                    view_id = *parent_id;
1076                    Some(view_id)
1077                } else {
1078                    None
1079                }
1080            }))
1081    }
1082
1083    // Traverses the parent tree. Walks down the tree toward the passed
1084    // view calling visit with true. Then walks back up the tree calling visit with false.
1085    // If `visit` returns false this function will immediately return.
1086    fn visit_dispatch_path(
1087        &mut self,
1088        view_id: usize,
1089        mut visit: impl FnMut(usize, bool, &mut WindowContext) -> bool,
1090    ) {
1091        // List of view ids from the leaf to the root of the window
1092        let path = self.ancestors(view_id).collect::<Vec<_>>();
1093
1094        // Walk down from the root to the leaf calling visit with capture_phase = true
1095        for view_id in path.iter().rev() {
1096            if !visit(*view_id, true, self) {
1097                return;
1098            }
1099        }
1100
1101        // Walk up from the leaf to the root calling visit with capture_phase = false
1102        for view_id in path.iter() {
1103            if !visit(*view_id, false, self) {
1104                return;
1105            }
1106        }
1107    }
1108
1109    pub fn focused_view_id(&self) -> Option<usize> {
1110        self.window.focused_view_id
1111    }
1112
1113    pub fn focus(&mut self, view_id: Option<usize>) {
1114        self.app_context.focus(self.window_id, view_id);
1115    }
1116
1117    pub fn window_bounds(&self) -> WindowBounds {
1118        self.window.platform_window.bounds()
1119    }
1120
1121    pub fn window_appearance(&self) -> Appearance {
1122        self.window.appearance
1123    }
1124
1125    pub fn window_display_uuid(&self) -> Option<Uuid> {
1126        self.window.platform_window.screen().display_uuid()
1127    }
1128
1129    pub fn show_character_palette(&self) {
1130        self.window.platform_window.show_character_palette();
1131    }
1132
1133    pub fn minimize_window(&self) {
1134        self.window.platform_window.minimize();
1135    }
1136
1137    pub fn zoom_window(&self) {
1138        self.window.platform_window.zoom();
1139    }
1140
1141    pub fn toggle_full_screen(&self) {
1142        self.window.platform_window.toggle_full_screen();
1143    }
1144
1145    pub fn prompt(
1146        &self,
1147        level: PromptLevel,
1148        msg: &str,
1149        answers: &[&str],
1150    ) -> oneshot::Receiver<usize> {
1151        self.window.platform_window.prompt(level, msg, answers)
1152    }
1153
1154    pub fn replace_root_view<V, F>(&mut self, build_root_view: F) -> ViewHandle<V>
1155    where
1156        V: View,
1157        F: FnOnce(&mut ViewContext<V>) -> V,
1158    {
1159        let root_view = self.add_view(|cx| build_root_view(cx));
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 fn add_view<T, F>(&mut self, build_view: F) -> ViewHandle<T>
1166    where
1167        T: View,
1168        F: FnOnce(&mut ViewContext<T>) -> T,
1169    {
1170        self.add_option_view(|cx| Some(build_view(cx))).unwrap()
1171    }
1172
1173    pub fn add_option_view<T, F>(&mut self, build_view: F) -> Option<ViewHandle<T>>
1174    where
1175        T: View,
1176        F: FnOnce(&mut ViewContext<T>) -> Option<T>,
1177    {
1178        let window_id = self.window_id;
1179        let view_id = post_inc(&mut self.next_entity_id);
1180        let mut cx = ViewContext::mutable(self, view_id);
1181        let handle = if let Some(view) = build_view(&mut cx) {
1182            let mut keymap_context = KeymapContext::default();
1183            view.update_keymap_context(&mut keymap_context, cx.app_context());
1184            self.views_metadata.insert(
1185                (window_id, view_id),
1186                ViewMetadata {
1187                    type_id: TypeId::of::<T>(),
1188                    keymap_context,
1189                },
1190            );
1191            self.views.insert((window_id, view_id), Box::new(view));
1192            self.window
1193                .invalidation
1194                .get_or_insert_with(Default::default)
1195                .updated
1196                .insert(view_id);
1197            Some(ViewHandle::new(window_id, view_id, &self.ref_counts))
1198        } else {
1199            None
1200        };
1201        handle
1202    }
1203}
1204
1205pub struct RenderParams {
1206    pub view_id: usize,
1207    pub titlebar_height: f32,
1208    pub refreshing: bool,
1209    pub appearance: Appearance,
1210}
1211
1212#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
1213pub enum Axis {
1214    #[default]
1215    Horizontal,
1216    Vertical,
1217}
1218
1219impl Axis {
1220    pub fn invert(self) -> Self {
1221        match self {
1222            Self::Horizontal => Self::Vertical,
1223            Self::Vertical => Self::Horizontal,
1224        }
1225    }
1226
1227    pub fn component(&self, point: Vector2F) -> f32 {
1228        match self {
1229            Self::Horizontal => point.x(),
1230            Self::Vertical => point.y(),
1231        }
1232    }
1233}
1234
1235impl ToJson for Axis {
1236    fn to_json(&self) -> serde_json::Value {
1237        match self {
1238            Axis::Horizontal => json!("horizontal"),
1239            Axis::Vertical => json!("vertical"),
1240        }
1241    }
1242}
1243
1244impl StaticColumnCount for Axis {}
1245impl Bind for Axis {
1246    fn bind(&self, statement: &Statement, start_index: i32) -> anyhow::Result<i32> {
1247        match self {
1248            Axis::Horizontal => "Horizontal",
1249            Axis::Vertical => "Vertical",
1250        }
1251        .bind(statement, start_index)
1252    }
1253}
1254
1255impl Column for Axis {
1256    fn column(statement: &mut Statement, start_index: i32) -> anyhow::Result<(Self, i32)> {
1257        String::column(statement, start_index).and_then(|(axis_text, next_index)| {
1258            Ok((
1259                match axis_text.as_str() {
1260                    "Horizontal" => Axis::Horizontal,
1261                    "Vertical" => Axis::Vertical,
1262                    _ => bail!("Stored serialized item kind is incorrect"),
1263                },
1264                next_index,
1265            ))
1266        })
1267    }
1268}
1269
1270pub trait Vector2FExt {
1271    fn along(self, axis: Axis) -> f32;
1272}
1273
1274impl Vector2FExt for Vector2F {
1275    fn along(self, axis: Axis) -> f32 {
1276        match axis {
1277            Axis::Horizontal => self.x(),
1278            Axis::Vertical => self.y(),
1279        }
1280    }
1281}
1282
1283pub trait RectFExt {
1284    fn length_along(self, axis: Axis) -> f32;
1285}
1286
1287impl RectFExt for RectF {
1288    fn length_along(self, axis: Axis) -> f32 {
1289        match axis {
1290            Axis::Horizontal => self.width(),
1291            Axis::Vertical => self.height(),
1292        }
1293    }
1294}
1295
1296#[derive(Copy, Clone, Debug)]
1297pub struct SizeConstraint {
1298    pub min: Vector2F,
1299    pub max: Vector2F,
1300}
1301
1302impl SizeConstraint {
1303    pub fn new(min: Vector2F, max: Vector2F) -> Self {
1304        Self { min, max }
1305    }
1306
1307    pub fn strict(size: Vector2F) -> Self {
1308        Self {
1309            min: size,
1310            max: size,
1311        }
1312    }
1313
1314    pub fn strict_along(axis: Axis, max: f32) -> Self {
1315        match axis {
1316            Axis::Horizontal => Self {
1317                min: vec2f(max, 0.0),
1318                max: vec2f(max, f32::INFINITY),
1319            },
1320            Axis::Vertical => Self {
1321                min: vec2f(0.0, max),
1322                max: vec2f(f32::INFINITY, max),
1323            },
1324        }
1325    }
1326
1327    pub fn max_along(&self, axis: Axis) -> f32 {
1328        match axis {
1329            Axis::Horizontal => self.max.x(),
1330            Axis::Vertical => self.max.y(),
1331        }
1332    }
1333
1334    pub fn min_along(&self, axis: Axis) -> f32 {
1335        match axis {
1336            Axis::Horizontal => self.min.x(),
1337            Axis::Vertical => self.min.y(),
1338        }
1339    }
1340
1341    pub fn constrain(&self, size: Vector2F) -> Vector2F {
1342        vec2f(
1343            size.x().min(self.max.x()).max(self.min.x()),
1344            size.y().min(self.max.y()).max(self.min.y()),
1345        )
1346    }
1347}
1348
1349impl Default for SizeConstraint {
1350    fn default() -> Self {
1351        SizeConstraint {
1352            min: Vector2F::zero(),
1353            max: Vector2F::splat(f32::INFINITY),
1354        }
1355    }
1356}
1357
1358impl ToJson for SizeConstraint {
1359    fn to_json(&self) -> serde_json::Value {
1360        json!({
1361            "min": self.min.to_json(),
1362            "max": self.max.to_json(),
1363        })
1364    }
1365}
1366
1367pub struct ChildView {
1368    view_id: usize,
1369    view_name: &'static str,
1370}
1371
1372impl ChildView {
1373    pub fn new(view: &AnyViewHandle, cx: &AppContext) -> Self {
1374        let view_name = cx.view_ui_name(view.window_id(), view.id()).unwrap();
1375        Self {
1376            view_id: view.id(),
1377            view_name,
1378        }
1379    }
1380}
1381
1382impl<V: View> Element<V> for ChildView {
1383    type LayoutState = ();
1384    type PaintState = ();
1385
1386    fn layout(
1387        &mut self,
1388        constraint: SizeConstraint,
1389        _: &mut V,
1390        cx: &mut LayoutContext<V>,
1391    ) -> (Vector2F, Self::LayoutState) {
1392        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1393            cx.new_parents.insert(self.view_id, cx.view_id());
1394            let size = rendered_view
1395                .layout(
1396                    constraint,
1397                    cx.new_parents,
1398                    cx.views_to_notify_if_ancestors_change,
1399                    cx.refreshing,
1400                    cx.view_context,
1401                )
1402                .log_err()
1403                .unwrap_or(Vector2F::zero());
1404            cx.window.rendered_views.insert(self.view_id, rendered_view);
1405            (size, ())
1406        } else {
1407            log::error!(
1408                "layout called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1409                self.view_id,
1410                self.view_name
1411            );
1412            (Vector2F::zero(), ())
1413        }
1414    }
1415
1416    fn paint(
1417        &mut self,
1418        scene: &mut SceneBuilder,
1419        bounds: RectF,
1420        visible_bounds: RectF,
1421        _: &mut Self::LayoutState,
1422        _: &mut V,
1423        cx: &mut ViewContext<V>,
1424    ) {
1425        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1426            rendered_view
1427                .paint(scene, bounds.origin(), visible_bounds, cx)
1428                .log_err();
1429            cx.window.rendered_views.insert(self.view_id, rendered_view);
1430        } else {
1431            log::error!(
1432                "paint called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1433                self.view_id,
1434                self.view_name
1435            );
1436        }
1437    }
1438
1439    fn rect_for_text_range(
1440        &self,
1441        range_utf16: Range<usize>,
1442        _: RectF,
1443        _: RectF,
1444        _: &Self::LayoutState,
1445        _: &Self::PaintState,
1446        _: &V,
1447        cx: &ViewContext<V>,
1448    ) -> Option<RectF> {
1449        if let Some(rendered_view) = cx.window.rendered_views.get(&self.view_id) {
1450            rendered_view
1451                .rect_for_text_range(range_utf16, &cx.window_context)
1452                .log_err()
1453                .flatten()
1454        } else {
1455            log::error!(
1456                "rect_for_text_range called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1457                self.view_id,
1458                self.view_name
1459            );
1460            None
1461        }
1462    }
1463
1464    fn debug(
1465        &self,
1466        bounds: RectF,
1467        _: &Self::LayoutState,
1468        _: &Self::PaintState,
1469        _: &V,
1470        cx: &ViewContext<V>,
1471    ) -> serde_json::Value {
1472        json!({
1473            "type": "ChildView",
1474            "bounds": bounds.to_json(),
1475            "child": if let Some(element) = cx.window.rendered_views.get(&self.view_id) {
1476                element.debug(&cx.window_context).log_err().unwrap_or_else(|| json!(null))
1477            } else {
1478                json!(null)
1479            }
1480        })
1481    }
1482}