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, NoAction, SceneBuilder,
  18    Subscription, 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_button: Option<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_button: 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_type = 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_type.extend(
 372                        actions
 373                            .keys()
 374                            .copied()
 375                            .map(|action_type| (action_type, depth)),
 376                    );
 377                }
 378            } else {
 379                log::error!(
 380                    "view {} not found when computing available actions",
 381                    view_id
 382                );
 383            }
 384        }
 385
 386        handler_depths_by_action_type.extend(
 387            self.global_actions
 388                .keys()
 389                .copied()
 390                .map(|action_type| (action_type, contexts.len())),
 391        );
 392
 393        self.action_deserializers
 394            .iter()
 395            .filter_map(move |(name, (type_id, deserialize))| {
 396                if let Some(action_depth) = handler_depths_by_action_type.get(type_id).copied() {
 397                    let action = deserialize(serde_json::Value::Object(Default::default())).ok()?;
 398                    let bindings = self
 399                        .keystroke_matcher
 400                        .bindings_for_action_type(*type_id)
 401                        .filter(|b| {
 402                            action.eq(b.action())
 403                                && (0..=action_depth)
 404                                    .any(|depth| b.match_context(&contexts[depth..]))
 405                        })
 406                        .cloned()
 407                        .collect();
 408                    Some((*name, action, bindings))
 409                } else {
 410                    None
 411                }
 412            })
 413            .collect()
 414    }
 415
 416    pub(crate) fn dispatch_keystroke(&mut self, keystroke: &Keystroke) -> bool {
 417        let window_id = self.window_id;
 418        if let Some(focused_view_id) = self.focused_view_id() {
 419            let dispatch_path = self
 420                .ancestors(focused_view_id)
 421                .filter_map(|view_id| {
 422                    self.views_metadata
 423                        .get(&(window_id, view_id))
 424                        .map(|view| (view_id, view.keymap_context.clone()))
 425                })
 426                .collect();
 427
 428            let match_result = self
 429                .keystroke_matcher
 430                .push_keystroke(keystroke.clone(), dispatch_path);
 431            let mut handled_by = None;
 432
 433            let keystroke_handled = match &match_result {
 434                MatchResult::None => false,
 435                MatchResult::Pending => true,
 436                MatchResult::Matches(matches) => {
 437                    let no_action_id = (NoAction {}).id();
 438                    for (view_id, action) in matches {
 439                        if action.id() == no_action_id {
 440                            return false;
 441                        }
 442                        if self.dispatch_action(Some(*view_id), action.as_ref()) {
 443                            self.keystroke_matcher.clear_pending();
 444                            handled_by = Some(action.boxed_clone());
 445                            break;
 446                        }
 447                    }
 448                    handled_by.is_some()
 449                }
 450            };
 451
 452            self.keystroke(
 453                window_id,
 454                keystroke.clone(),
 455                handled_by,
 456                match_result.clone(),
 457            );
 458            keystroke_handled
 459        } else {
 460            self.keystroke(window_id, keystroke.clone(), None, MatchResult::None);
 461            false
 462        }
 463    }
 464
 465    pub(crate) fn dispatch_event(&mut self, event: Event, event_reused: bool) -> bool {
 466        let mut mouse_events = SmallVec::<[_; 2]>::new();
 467        let mut notified_views: HashSet<usize> = Default::default();
 468        let window_id = self.window_id;
 469
 470        // 1. Handle platform event. Keyboard events get dispatched immediately, while mouse events
 471        //    get mapped into the mouse-specific MouseEvent type.
 472        //  -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
 473        //  -> Also updates mouse-related state
 474        match &event {
 475            Event::KeyDown(e) => return self.dispatch_key_down(e),
 476
 477            Event::KeyUp(e) => return self.dispatch_key_up(e),
 478
 479            Event::ModifiersChanged(e) => return self.dispatch_modifiers_changed(e),
 480
 481            Event::MouseDown(e) => {
 482                // Click events are weird because they can be fired after a drag event.
 483                // MDN says that browsers handle this by starting from 'the most
 484                // specific ancestor element that contained both [positions]'
 485                // So we need to store the overlapping regions on mouse down.
 486
 487                // If there is already clicked_button stored, don't replace it.
 488                if self.window.clicked_button.is_none() {
 489                    self.window.clicked_region_ids = self
 490                        .window
 491                        .mouse_regions
 492                        .iter()
 493                        .filter_map(|(region, _)| {
 494                            if region.bounds.contains_point(e.position) {
 495                                Some(region.id())
 496                            } else {
 497                                None
 498                            }
 499                        })
 500                        .collect();
 501
 502                    self.window.clicked_button = Some(e.button);
 503                }
 504
 505                mouse_events.push(MouseEvent::Down(MouseDown {
 506                    region: Default::default(),
 507                    platform_event: e.clone(),
 508                }));
 509                mouse_events.push(MouseEvent::DownOut(MouseDownOut {
 510                    region: Default::default(),
 511                    platform_event: e.clone(),
 512                }));
 513            }
 514
 515            Event::MouseUp(e) => {
 516                // NOTE: The order of event pushes is important! MouseUp events MUST be fired
 517                // before click events, and so the MouseUp events need to be pushed before
 518                // MouseClick events.
 519                mouse_events.push(MouseEvent::Up(MouseUp {
 520                    region: Default::default(),
 521                    platform_event: e.clone(),
 522                }));
 523                mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 524                    region: Default::default(),
 525                    platform_event: e.clone(),
 526                }));
 527                mouse_events.push(MouseEvent::Click(MouseClick {
 528                    region: Default::default(),
 529                    platform_event: e.clone(),
 530                }));
 531                mouse_events.push(MouseEvent::ClickOut(MouseClickOut {
 532                    region: Default::default(),
 533                    platform_event: e.clone(),
 534                }));
 535            }
 536
 537            Event::MouseMoved(
 538                e @ MouseMovedEvent {
 539                    position,
 540                    pressed_button,
 541                    ..
 542                },
 543            ) => {
 544                let mut style_to_assign = CursorStyle::Arrow;
 545                for region in self.window.cursor_regions.iter().rev() {
 546                    if region.bounds.contains_point(*position) {
 547                        style_to_assign = region.style;
 548                        break;
 549                    }
 550                }
 551
 552                if self
 553                    .window
 554                    .platform_window
 555                    .is_topmost_for_position(*position)
 556                {
 557                    self.platform().set_cursor_style(style_to_assign);
 558                }
 559
 560                if !event_reused {
 561                    if pressed_button.is_some() {
 562                        mouse_events.push(MouseEvent::Drag(MouseDrag {
 563                            region: Default::default(),
 564                            prev_mouse_position: self.window.mouse_position,
 565                            platform_event: e.clone(),
 566                        }));
 567                    } else if let Some(clicked_button) = self.window.clicked_button {
 568                        // Mouse up event happened outside the current window. Simulate mouse up button event
 569                        let button_event = e.to_button_event(clicked_button);
 570                        mouse_events.push(MouseEvent::Up(MouseUp {
 571                            region: Default::default(),
 572                            platform_event: button_event.clone(),
 573                        }));
 574                        mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 575                            region: Default::default(),
 576                            platform_event: button_event.clone(),
 577                        }));
 578                        mouse_events.push(MouseEvent::Click(MouseClick {
 579                            region: Default::default(),
 580                            platform_event: button_event.clone(),
 581                        }));
 582                    }
 583
 584                    mouse_events.push(MouseEvent::Move(MouseMove {
 585                        region: Default::default(),
 586                        platform_event: e.clone(),
 587                    }));
 588                }
 589
 590                mouse_events.push(MouseEvent::Hover(MouseHover {
 591                    region: Default::default(),
 592                    platform_event: e.clone(),
 593                    started: false,
 594                }));
 595                mouse_events.push(MouseEvent::MoveOut(MouseMoveOut {
 596                    region: Default::default(),
 597                }));
 598
 599                self.window.last_mouse_moved_event = Some(event.clone());
 600            }
 601
 602            Event::MouseExited(event) => {
 603                // When the platform sends a MouseExited event, synthesize
 604                // a MouseMoved event whose position is outside the window's
 605                // bounds so that hover and cursor state can be updated.
 606                return self.dispatch_event(
 607                    Event::MouseMoved(MouseMovedEvent {
 608                        position: event.position,
 609                        pressed_button: event.pressed_button,
 610                        modifiers: event.modifiers,
 611                    }),
 612                    event_reused,
 613                );
 614            }
 615
 616            Event::ScrollWheel(e) => mouse_events.push(MouseEvent::ScrollWheel(MouseScrollWheel {
 617                region: Default::default(),
 618                platform_event: e.clone(),
 619            })),
 620        }
 621
 622        if let Some(position) = event.position() {
 623            self.window.mouse_position = position;
 624        }
 625
 626        // 2. Dispatch mouse events on regions
 627        let mut any_event_handled = false;
 628        for mut mouse_event in mouse_events {
 629            let mut valid_regions = Vec::new();
 630
 631            // GPUI elements are arranged by z_index but sibling elements can register overlapping
 632            // mouse regions. As such, hover events are only fired on overlapping elements which
 633            // are at the same z-index as the topmost element which overlaps with the mouse.
 634            match &mouse_event {
 635                MouseEvent::Hover(_) => {
 636                    let mut highest_z_index = None;
 637                    let mouse_position = self.window.mouse_position.clone();
 638                    let window = &mut *self.window;
 639                    for (region, z_index) in window.mouse_regions.iter().rev() {
 640                        // Allow mouse regions to appear transparent to hovers
 641                        if !region.hoverable {
 642                            continue;
 643                        }
 644
 645                        let contains_mouse = region.bounds.contains_point(mouse_position);
 646
 647                        if contains_mouse && highest_z_index.is_none() {
 648                            highest_z_index = Some(z_index);
 649                        }
 650
 651                        // This unwrap relies on short circuiting boolean expressions
 652                        // The right side of the && is only executed when contains_mouse
 653                        // is true, and we know above that when contains_mouse is true
 654                        // highest_z_index is set.
 655                        if contains_mouse && z_index == highest_z_index.unwrap() {
 656                            //Ensure that hover entrance events aren't sent twice
 657                            if window.hovered_region_ids.insert(region.id()) {
 658                                valid_regions.push(region.clone());
 659                                if region.notify_on_hover {
 660                                    notified_views.insert(region.id().view_id());
 661                                }
 662                            }
 663                        } else {
 664                            // Ensure that hover exit events aren't sent twice
 665                            if window.hovered_region_ids.remove(&region.id()) {
 666                                valid_regions.push(region.clone());
 667                                if region.notify_on_hover {
 668                                    notified_views.insert(region.id().view_id());
 669                                }
 670                            }
 671                        }
 672                    }
 673                }
 674
 675                MouseEvent::Down(_) | MouseEvent::Up(_) => {
 676                    for (region, _) in self.window.mouse_regions.iter().rev() {
 677                        if region.bounds.contains_point(self.window.mouse_position) {
 678                            valid_regions.push(region.clone());
 679                            if region.notify_on_click {
 680                                notified_views.insert(region.id().view_id());
 681                            }
 682                        }
 683                    }
 684                }
 685
 686                MouseEvent::Click(e) => {
 687                    // Only raise click events if the released button is the same as the one stored
 688                    if self
 689                        .window
 690                        .clicked_button
 691                        .map(|clicked_button| clicked_button == e.button)
 692                        .unwrap_or(false)
 693                    {
 694                        // Clear clicked regions and clicked button
 695                        let clicked_region_ids = std::mem::replace(
 696                            &mut self.window.clicked_region_ids,
 697                            Default::default(),
 698                        );
 699                        self.window.clicked_button = None;
 700
 701                        // Find regions which still overlap with the mouse since the last MouseDown happened
 702                        for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 703                            if clicked_region_ids.contains(&mouse_region.id()) {
 704                                if mouse_region
 705                                    .bounds
 706                                    .contains_point(self.window.mouse_position)
 707                                {
 708                                    valid_regions.push(mouse_region.clone());
 709                                }
 710                            }
 711                        }
 712                    }
 713                }
 714
 715                MouseEvent::Drag(_) => {
 716                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 717                        if self.window.clicked_region_ids.contains(&mouse_region.id()) {
 718                            valid_regions.push(mouse_region.clone());
 719                        }
 720                    }
 721                }
 722
 723                MouseEvent::MoveOut(_)
 724                | MouseEvent::UpOut(_)
 725                | MouseEvent::DownOut(_)
 726                | MouseEvent::ClickOut(_) => {
 727                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 728                        // NOT contains
 729                        if !mouse_region
 730                            .bounds
 731                            .contains_point(self.window.mouse_position)
 732                        {
 733                            valid_regions.push(mouse_region.clone());
 734                        }
 735                    }
 736                }
 737
 738                _ => {
 739                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 740                        // Contains
 741                        if mouse_region
 742                            .bounds
 743                            .contains_point(self.window.mouse_position)
 744                        {
 745                            valid_regions.push(mouse_region.clone());
 746                        }
 747                    }
 748                }
 749            }
 750
 751            //3. Fire region events
 752            let hovered_region_ids = self.window.hovered_region_ids.clone();
 753            for valid_region in valid_regions.into_iter() {
 754                let mut handled = false;
 755                mouse_event.set_region(valid_region.bounds);
 756                if let MouseEvent::Hover(e) = &mut mouse_event {
 757                    e.started = hovered_region_ids.contains(&valid_region.id())
 758                }
 759                // Handle Down events if the MouseRegion has a Click or Drag handler. This makes the api more intuitive as you would
 760                // not expect a MouseRegion to be transparent to Down events if it also has a Click handler.
 761                // This behavior can be overridden by adding a Down handler
 762                if let MouseEvent::Down(e) = &mouse_event {
 763                    let has_click = valid_region
 764                        .handlers
 765                        .contains(MouseEvent::click_disc(), Some(e.button));
 766                    let has_drag = valid_region
 767                        .handlers
 768                        .contains(MouseEvent::drag_disc(), Some(e.button));
 769                    let has_down = valid_region
 770                        .handlers
 771                        .contains(MouseEvent::down_disc(), Some(e.button));
 772                    if !has_down && (has_click || has_drag) {
 773                        handled = true;
 774                    }
 775                }
 776
 777                // `event_consumed` should only be true if there are any handlers for this event.
 778                let mut event_consumed = handled;
 779                if let Some(callbacks) = valid_region.handlers.get(&mouse_event.handler_key()) {
 780                    for callback in callbacks {
 781                        handled = true;
 782                        let view_id = valid_region.id().view_id();
 783                        self.update_any_view(view_id, |view, cx| {
 784                            handled = callback(mouse_event.clone(), view.as_any_mut(), cx, view_id);
 785                        });
 786                        event_consumed |= handled;
 787                        any_event_handled |= handled;
 788                    }
 789                }
 790
 791                any_event_handled |= handled;
 792
 793                // For bubbling events, if the event was handled, don't continue dispatching.
 794                // This only makes sense for local events which return false from is_capturable.
 795                if event_consumed && mouse_event.is_capturable() {
 796                    break;
 797                }
 798            }
 799        }
 800
 801        for view_id in notified_views {
 802            self.notify_view(window_id, view_id);
 803        }
 804
 805        any_event_handled
 806    }
 807
 808    pub(crate) fn dispatch_key_down(&mut self, event: &KeyDownEvent) -> bool {
 809        let window_id = self.window_id;
 810        if let Some(focused_view_id) = self.window.focused_view_id {
 811            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 812                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 813                    let handled = view.key_down(event, self, view_id);
 814                    self.views.insert((window_id, view_id), view);
 815                    if handled {
 816                        return true;
 817                    }
 818                } else {
 819                    log::error!("view {} does not exist", view_id)
 820                }
 821            }
 822        }
 823
 824        false
 825    }
 826
 827    pub(crate) fn dispatch_key_up(&mut self, event: &KeyUpEvent) -> bool {
 828        let window_id = self.window_id;
 829        if let Some(focused_view_id) = self.window.focused_view_id {
 830            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 831                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 832                    let handled = view.key_up(event, self, view_id);
 833                    self.views.insert((window_id, view_id), view);
 834                    if handled {
 835                        return true;
 836                    }
 837                } else {
 838                    log::error!("view {} does not exist", view_id)
 839                }
 840            }
 841        }
 842
 843        false
 844    }
 845
 846    pub(crate) fn dispatch_modifiers_changed(&mut self, event: &ModifiersChangedEvent) -> bool {
 847        let window_id = self.window_id;
 848        if let Some(focused_view_id) = self.window.focused_view_id {
 849            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 850                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 851                    let handled = view.modifiers_changed(event, self, view_id);
 852                    self.views.insert((window_id, view_id), view);
 853                    if handled {
 854                        return true;
 855                    }
 856                } else {
 857                    log::error!("view {} does not exist", view_id)
 858                }
 859            }
 860        }
 861
 862        false
 863    }
 864
 865    pub fn invalidate(&mut self, mut invalidation: WindowInvalidation, appearance: Appearance) {
 866        self.start_frame();
 867        self.window.appearance = appearance;
 868        for view_id in &invalidation.removed {
 869            invalidation.updated.remove(view_id);
 870            self.window.rendered_views.remove(view_id);
 871        }
 872        for view_id in &invalidation.updated {
 873            let titlebar_height = self.window.titlebar_height;
 874            let hovered_region_ids = self.window.hovered_region_ids.clone();
 875            let clicked_region_ids = self
 876                .window
 877                .clicked_button
 878                .map(|button| (self.window.clicked_region_ids.clone(), button));
 879
 880            let element = self
 881                .render_view(RenderParams {
 882                    view_id: *view_id,
 883                    titlebar_height,
 884                    hovered_region_ids,
 885                    clicked_region_ids,
 886                    refreshing: false,
 887                    appearance,
 888                })
 889                .unwrap();
 890            self.window.rendered_views.insert(*view_id, element);
 891        }
 892    }
 893
 894    pub fn render_view(&mut self, params: RenderParams) -> Result<Box<dyn AnyRootElement>> {
 895        let window_id = self.window_id;
 896        let view_id = params.view_id;
 897        let mut view = self
 898            .views
 899            .remove(&(window_id, view_id))
 900            .ok_or_else(|| anyhow!("view not found"))?;
 901        let element = view.render(self, view_id);
 902        self.views.insert((window_id, view_id), view);
 903        Ok(element)
 904    }
 905
 906    pub(crate) fn layout(&mut self, refreshing: bool) -> Result<HashMap<usize, usize>> {
 907        let window_size = self.window.platform_window.content_size();
 908        let root_view_id = self.window.root_view().id();
 909        let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
 910        let mut new_parents = HashMap::default();
 911        let mut views_to_notify_if_ancestors_change = HashMap::default();
 912        rendered_root.layout(
 913            SizeConstraint::strict(window_size),
 914            &mut new_parents,
 915            &mut views_to_notify_if_ancestors_change,
 916            refreshing,
 917            self,
 918        )?;
 919
 920        for (view_id, view_ids_to_notify) in views_to_notify_if_ancestors_change {
 921            let mut current_view_id = view_id;
 922            loop {
 923                let old_parent_id = self.window.parents.get(&current_view_id);
 924                let new_parent_id = new_parents.get(&current_view_id);
 925                if old_parent_id.is_none() && new_parent_id.is_none() {
 926                    break;
 927                } else if old_parent_id == new_parent_id {
 928                    current_view_id = *old_parent_id.unwrap();
 929                } else {
 930                    let window_id = self.window_id;
 931                    for view_id_to_notify in view_ids_to_notify {
 932                        self.notify_view(window_id, view_id_to_notify);
 933                    }
 934                    break;
 935                }
 936            }
 937        }
 938
 939        let old_parents = mem::replace(&mut self.window.parents, new_parents);
 940        self.window
 941            .rendered_views
 942            .insert(root_view_id, rendered_root);
 943        Ok(old_parents)
 944    }
 945
 946    pub(crate) fn paint(&mut self) -> Result<Scene> {
 947        let window_size = self.window.platform_window.content_size();
 948        let scale_factor = self.window.platform_window.scale_factor();
 949
 950        let root_view_id = self.window.root_view().id();
 951        let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
 952
 953        let mut scene_builder = SceneBuilder::new(scale_factor);
 954        rendered_root.paint(
 955            &mut scene_builder,
 956            Vector2F::zero(),
 957            RectF::from_points(Vector2F::zero(), window_size),
 958            self,
 959        )?;
 960        self.window
 961            .rendered_views
 962            .insert(root_view_id, rendered_root);
 963
 964        self.window.text_layout_cache.finish_frame();
 965        let scene = scene_builder.build();
 966        self.window.cursor_regions = scene.cursor_regions();
 967        self.window.mouse_regions = scene.mouse_regions();
 968
 969        if self.window_is_active() {
 970            if let Some(event) = self.window.last_mouse_moved_event.clone() {
 971                self.dispatch_event(event, true);
 972            }
 973        }
 974
 975        Ok(scene)
 976    }
 977
 978    pub fn rect_for_text_range(&self, range_utf16: Range<usize>) -> Option<RectF> {
 979        let focused_view_id = self.window.focused_view_id?;
 980        self.window
 981            .rendered_views
 982            .get(&focused_view_id)?
 983            .rect_for_text_range(range_utf16, self)
 984            .log_err()
 985            .flatten()
 986    }
 987
 988    pub fn set_window_title(&mut self, title: &str) {
 989        self.window.platform_window.set_title(title);
 990    }
 991
 992    pub fn set_window_edited(&mut self, edited: bool) {
 993        self.window.platform_window.set_edited(edited);
 994    }
 995
 996    pub fn is_topmost_window_for_position(&self, position: Vector2F) -> bool {
 997        self.window
 998            .platform_window
 999            .is_topmost_for_position(position)
1000    }
1001
1002    pub fn activate_window(&self) {
1003        self.window.platform_window.activate();
1004    }
1005
1006    pub fn window_is_active(&self) -> bool {
1007        self.window.is_active
1008    }
1009
1010    pub fn window_is_fullscreen(&self) -> bool {
1011        self.window.is_fullscreen
1012    }
1013
1014    pub(crate) fn dispatch_action(&mut self, view_id: Option<usize>, action: &dyn Action) -> bool {
1015        if let Some(view_id) = view_id {
1016            self.halt_action_dispatch = false;
1017            self.visit_dispatch_path(view_id, |view_id, capture_phase, cx| {
1018                cx.update_any_view(view_id, |view, cx| {
1019                    let type_id = view.as_any().type_id();
1020                    if let Some((name, mut handlers)) = cx
1021                        .actions_mut(capture_phase)
1022                        .get_mut(&type_id)
1023                        .and_then(|h| h.remove_entry(&action.id()))
1024                    {
1025                        for handler in handlers.iter_mut().rev() {
1026                            cx.halt_action_dispatch = true;
1027                            handler(view, action, cx, view_id);
1028                            if cx.halt_action_dispatch {
1029                                break;
1030                            }
1031                        }
1032                        cx.actions_mut(capture_phase)
1033                            .get_mut(&type_id)
1034                            .unwrap()
1035                            .insert(name, handlers);
1036                    }
1037                });
1038
1039                !cx.halt_action_dispatch
1040            });
1041        }
1042
1043        if !self.halt_action_dispatch {
1044            self.halt_action_dispatch = self.dispatch_global_action_any(action);
1045        }
1046
1047        self.pending_effects
1048            .push_back(Effect::ActionDispatchNotification {
1049                action_id: action.id(),
1050            });
1051        self.halt_action_dispatch
1052    }
1053
1054    /// Returns an iterator over all of the view ids from the passed view up to the root of the window
1055    /// Includes the passed view itself
1056    pub(crate) fn ancestors(&self, mut view_id: usize) -> impl Iterator<Item = usize> + '_ {
1057        std::iter::once(view_id)
1058            .into_iter()
1059            .chain(std::iter::from_fn(move || {
1060                if let Some(parent_id) = self.window.parents.get(&view_id) {
1061                    view_id = *parent_id;
1062                    Some(view_id)
1063                } else {
1064                    None
1065                }
1066            }))
1067    }
1068
1069    // Traverses the parent tree. Walks down the tree toward the passed
1070    // view calling visit with true. Then walks back up the tree calling visit with false.
1071    // If `visit` returns false this function will immediately return.
1072    fn visit_dispatch_path(
1073        &mut self,
1074        view_id: usize,
1075        mut visit: impl FnMut(usize, bool, &mut WindowContext) -> bool,
1076    ) {
1077        // List of view ids from the leaf to the root of the window
1078        let path = self.ancestors(view_id).collect::<Vec<_>>();
1079
1080        // Walk down from the root to the leaf calling visit with capture_phase = true
1081        for view_id in path.iter().rev() {
1082            if !visit(*view_id, true, self) {
1083                return;
1084            }
1085        }
1086
1087        // Walk up from the leaf to the root calling visit with capture_phase = false
1088        for view_id in path.iter() {
1089            if !visit(*view_id, false, self) {
1090                return;
1091            }
1092        }
1093    }
1094
1095    pub fn focused_view_id(&self) -> Option<usize> {
1096        self.window.focused_view_id
1097    }
1098
1099    pub fn focus(&mut self, view_id: Option<usize>) {
1100        self.app_context.focus(self.window_id, view_id);
1101    }
1102
1103    pub fn window_bounds(&self) -> WindowBounds {
1104        self.window.platform_window.bounds()
1105    }
1106
1107    pub fn window_appearance(&self) -> Appearance {
1108        self.window.appearance
1109    }
1110
1111    pub fn window_display_uuid(&self) -> Option<Uuid> {
1112        self.window.platform_window.screen().display_uuid()
1113    }
1114
1115    pub fn show_character_palette(&self) {
1116        self.window.platform_window.show_character_palette();
1117    }
1118
1119    pub fn minimize_window(&self) {
1120        self.window.platform_window.minimize();
1121    }
1122
1123    pub fn zoom_window(&self) {
1124        self.window.platform_window.zoom();
1125    }
1126
1127    pub fn toggle_full_screen(&self) {
1128        self.window.platform_window.toggle_full_screen();
1129    }
1130
1131    pub fn prompt(
1132        &self,
1133        level: PromptLevel,
1134        msg: &str,
1135        answers: &[&str],
1136    ) -> oneshot::Receiver<usize> {
1137        self.window.platform_window.prompt(level, msg, answers)
1138    }
1139
1140    pub fn replace_root_view<V, F>(&mut self, build_root_view: F) -> ViewHandle<V>
1141    where
1142        V: View,
1143        F: FnOnce(&mut ViewContext<V>) -> V,
1144    {
1145        let root_view = self.add_view(|cx| build_root_view(cx));
1146        self.window.root_view = Some(root_view.clone().into_any());
1147        self.window.focused_view_id = Some(root_view.id());
1148        root_view
1149    }
1150
1151    pub fn add_view<T, F>(&mut self, build_view: F) -> ViewHandle<T>
1152    where
1153        T: View,
1154        F: FnOnce(&mut ViewContext<T>) -> T,
1155    {
1156        self.add_option_view(|cx| Some(build_view(cx))).unwrap()
1157    }
1158
1159    pub fn add_option_view<T, F>(&mut self, build_view: F) -> Option<ViewHandle<T>>
1160    where
1161        T: View,
1162        F: FnOnce(&mut ViewContext<T>) -> Option<T>,
1163    {
1164        let window_id = self.window_id;
1165        let view_id = post_inc(&mut self.next_entity_id);
1166        let mut cx = ViewContext::mutable(self, view_id);
1167        let handle = if let Some(view) = build_view(&mut cx) {
1168            let mut keymap_context = KeymapContext::default();
1169            view.update_keymap_context(&mut keymap_context, cx.app_context());
1170            self.views_metadata.insert(
1171                (window_id, view_id),
1172                ViewMetadata {
1173                    type_id: TypeId::of::<T>(),
1174                    keymap_context,
1175                },
1176            );
1177            self.views.insert((window_id, view_id), Box::new(view));
1178            self.window
1179                .invalidation
1180                .get_or_insert_with(Default::default)
1181                .updated
1182                .insert(view_id);
1183            Some(ViewHandle::new(window_id, view_id, &self.ref_counts))
1184        } else {
1185            None
1186        };
1187        handle
1188    }
1189}
1190
1191pub struct RenderParams {
1192    pub view_id: usize,
1193    pub titlebar_height: f32,
1194    pub hovered_region_ids: HashSet<MouseRegionId>,
1195    pub clicked_region_ids: Option<(HashSet<MouseRegionId>, MouseButton)>,
1196    pub refreshing: bool,
1197    pub appearance: Appearance,
1198}
1199
1200#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
1201pub enum Axis {
1202    #[default]
1203    Horizontal,
1204    Vertical,
1205}
1206
1207impl Axis {
1208    pub fn invert(self) -> Self {
1209        match self {
1210            Self::Horizontal => Self::Vertical,
1211            Self::Vertical => Self::Horizontal,
1212        }
1213    }
1214
1215    pub fn component(&self, point: Vector2F) -> f32 {
1216        match self {
1217            Self::Horizontal => point.x(),
1218            Self::Vertical => point.y(),
1219        }
1220    }
1221}
1222
1223impl ToJson for Axis {
1224    fn to_json(&self) -> serde_json::Value {
1225        match self {
1226            Axis::Horizontal => json!("horizontal"),
1227            Axis::Vertical => json!("vertical"),
1228        }
1229    }
1230}
1231
1232impl StaticColumnCount for Axis {}
1233impl Bind for Axis {
1234    fn bind(&self, statement: &Statement, start_index: i32) -> anyhow::Result<i32> {
1235        match self {
1236            Axis::Horizontal => "Horizontal",
1237            Axis::Vertical => "Vertical",
1238        }
1239        .bind(statement, start_index)
1240    }
1241}
1242
1243impl Column for Axis {
1244    fn column(statement: &mut Statement, start_index: i32) -> anyhow::Result<(Self, i32)> {
1245        String::column(statement, start_index).and_then(|(axis_text, next_index)| {
1246            Ok((
1247                match axis_text.as_str() {
1248                    "Horizontal" => Axis::Horizontal,
1249                    "Vertical" => Axis::Vertical,
1250                    _ => bail!("Stored serialized item kind is incorrect"),
1251                },
1252                next_index,
1253            ))
1254        })
1255    }
1256}
1257
1258pub trait Vector2FExt {
1259    fn along(self, axis: Axis) -> f32;
1260}
1261
1262impl Vector2FExt for Vector2F {
1263    fn along(self, axis: Axis) -> f32 {
1264        match axis {
1265            Axis::Horizontal => self.x(),
1266            Axis::Vertical => self.y(),
1267        }
1268    }
1269}
1270
1271#[derive(Copy, Clone, Debug)]
1272pub struct SizeConstraint {
1273    pub min: Vector2F,
1274    pub max: Vector2F,
1275}
1276
1277impl SizeConstraint {
1278    pub fn new(min: Vector2F, max: Vector2F) -> Self {
1279        Self { min, max }
1280    }
1281
1282    pub fn strict(size: Vector2F) -> Self {
1283        Self {
1284            min: size,
1285            max: size,
1286        }
1287    }
1288
1289    pub fn strict_along(axis: Axis, max: f32) -> Self {
1290        match axis {
1291            Axis::Horizontal => Self {
1292                min: vec2f(max, 0.0),
1293                max: vec2f(max, f32::INFINITY),
1294            },
1295            Axis::Vertical => Self {
1296                min: vec2f(0.0, max),
1297                max: vec2f(f32::INFINITY, max),
1298            },
1299        }
1300    }
1301
1302    pub fn max_along(&self, axis: Axis) -> f32 {
1303        match axis {
1304            Axis::Horizontal => self.max.x(),
1305            Axis::Vertical => self.max.y(),
1306        }
1307    }
1308
1309    pub fn min_along(&self, axis: Axis) -> f32 {
1310        match axis {
1311            Axis::Horizontal => self.min.x(),
1312            Axis::Vertical => self.min.y(),
1313        }
1314    }
1315
1316    pub fn constrain(&self, size: Vector2F) -> Vector2F {
1317        vec2f(
1318            size.x().min(self.max.x()).max(self.min.x()),
1319            size.y().min(self.max.y()).max(self.min.y()),
1320        )
1321    }
1322}
1323
1324impl Default for SizeConstraint {
1325    fn default() -> Self {
1326        SizeConstraint {
1327            min: Vector2F::zero(),
1328            max: Vector2F::splat(f32::INFINITY),
1329        }
1330    }
1331}
1332
1333impl ToJson for SizeConstraint {
1334    fn to_json(&self) -> serde_json::Value {
1335        json!({
1336            "min": self.min.to_json(),
1337            "max": self.max.to_json(),
1338        })
1339    }
1340}
1341
1342pub struct ChildView {
1343    view_id: usize,
1344    view_name: &'static str,
1345}
1346
1347impl ChildView {
1348    pub fn new(view: &AnyViewHandle, cx: &AppContext) -> Self {
1349        let view_name = cx.view_ui_name(view.window_id(), view.id()).unwrap();
1350        Self {
1351            view_id: view.id(),
1352            view_name,
1353        }
1354    }
1355}
1356
1357impl<V: View> Element<V> for ChildView {
1358    type LayoutState = ();
1359    type PaintState = ();
1360
1361    fn layout(
1362        &mut self,
1363        constraint: SizeConstraint,
1364        _: &mut V,
1365        cx: &mut LayoutContext<V>,
1366    ) -> (Vector2F, Self::LayoutState) {
1367        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1368            cx.new_parents.insert(self.view_id, cx.view_id());
1369            let size = rendered_view
1370                .layout(
1371                    constraint,
1372                    cx.new_parents,
1373                    cx.views_to_notify_if_ancestors_change,
1374                    cx.refreshing,
1375                    cx.view_context,
1376                )
1377                .log_err()
1378                .unwrap_or(Vector2F::zero());
1379            cx.window.rendered_views.insert(self.view_id, rendered_view);
1380            (size, ())
1381        } else {
1382            log::error!(
1383                "layout called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1384                self.view_id,
1385                self.view_name
1386            );
1387            (Vector2F::zero(), ())
1388        }
1389    }
1390
1391    fn paint(
1392        &mut self,
1393        scene: &mut SceneBuilder,
1394        bounds: RectF,
1395        visible_bounds: RectF,
1396        _: &mut Self::LayoutState,
1397        _: &mut V,
1398        cx: &mut ViewContext<V>,
1399    ) {
1400        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1401            rendered_view
1402                .paint(scene, bounds.origin(), visible_bounds, cx)
1403                .log_err();
1404            cx.window.rendered_views.insert(self.view_id, rendered_view);
1405        } else {
1406            log::error!(
1407                "paint called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1408                self.view_id,
1409                self.view_name
1410            );
1411        }
1412    }
1413
1414    fn rect_for_text_range(
1415        &self,
1416        range_utf16: Range<usize>,
1417        _: RectF,
1418        _: RectF,
1419        _: &Self::LayoutState,
1420        _: &Self::PaintState,
1421        _: &V,
1422        cx: &ViewContext<V>,
1423    ) -> Option<RectF> {
1424        if let Some(rendered_view) = cx.window.rendered_views.get(&self.view_id) {
1425            rendered_view
1426                .rect_for_text_range(range_utf16, &cx.window_context)
1427                .log_err()
1428                .flatten()
1429        } else {
1430            log::error!(
1431                "rect_for_text_range called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1432                self.view_id,
1433                self.view_name
1434            );
1435            None
1436        }
1437    }
1438
1439    fn debug(
1440        &self,
1441        bounds: RectF,
1442        _: &Self::LayoutState,
1443        _: &Self::PaintState,
1444        _: &V,
1445        cx: &ViewContext<V>,
1446    ) -> serde_json::Value {
1447        json!({
1448            "type": "ChildView",
1449            "bounds": bounds.to_json(),
1450            "child": if let Some(element) = cx.window.rendered_views.get(&self.view_id) {
1451                element.debug(&cx.window_context).log_err().unwrap_or_else(|| json!(null))
1452            } else {
1453                json!(null)
1454            }
1455        })
1456    }
1457}