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, WindowHandle, 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    type Result<T> = T;
 146
 147    fn read_window_with<T, F: FnOnce(&WindowContext) -> T>(&self, window_id: usize, f: F) -> T {
 148        if self.window_id == window_id {
 149            f(self)
 150        } else {
 151            panic!("read_with called with id of window that does not belong to this context")
 152        }
 153    }
 154
 155    fn update_window<T, F: FnOnce(&mut WindowContext) -> T>(
 156        &mut self,
 157        window_id: usize,
 158        f: F,
 159    ) -> T {
 160        if self.window_id == window_id {
 161            f(self)
 162        } else {
 163            panic!("update called with id of window that does not belong to this context")
 164        }
 165    }
 166}
 167
 168impl<'a> WindowContext<'a> {
 169    pub fn mutable(
 170        app_context: &'a mut AppContext,
 171        window: &'a mut Window,
 172        window_id: usize,
 173    ) -> Self {
 174        Self {
 175            app_context: Reference::Mutable(app_context),
 176            window: Reference::Mutable(window),
 177            window_id,
 178            removed: false,
 179        }
 180    }
 181
 182    pub fn immutable(app_context: &'a AppContext, window: &'a Window, window_id: usize) -> Self {
 183        Self {
 184            app_context: Reference::Immutable(app_context),
 185            window: Reference::Immutable(window),
 186            window_id,
 187            removed: false,
 188        }
 189    }
 190
 191    pub fn remove_window(&mut self) {
 192        self.removed = true;
 193    }
 194
 195    pub fn window_id(&self) -> usize {
 196        self.window_id
 197    }
 198
 199    pub fn app_context(&mut self) -> &mut AppContext {
 200        &mut self.app_context
 201    }
 202
 203    pub fn root_view(&self) -> &AnyViewHandle {
 204        self.window.root_view()
 205    }
 206
 207    pub fn window_size(&self) -> Vector2F {
 208        self.window.platform_window.content_size()
 209    }
 210
 211    pub fn text_layout_cache(&self) -> &TextLayoutCache {
 212        &self.window.text_layout_cache
 213    }
 214
 215    pub(crate) fn update_any_view<F, T>(&mut self, view_id: usize, f: F) -> Option<T>
 216    where
 217        F: FnOnce(&mut dyn AnyView, &mut Self) -> T,
 218    {
 219        let window_id = self.window_id;
 220        let mut view = self.views.remove(&(window_id, view_id))?;
 221        let result = f(view.as_mut(), self);
 222        self.views.insert((window_id, view_id), view);
 223        Some(result)
 224    }
 225
 226    pub(crate) fn update_view<T, S>(
 227        &mut self,
 228        handle: &ViewHandle<T>,
 229        update: &mut dyn FnMut(&mut T, &mut ViewContext<T>) -> S,
 230    ) -> S
 231    where
 232        T: View,
 233    {
 234        self.update_any_view(handle.view_id, |view, cx| {
 235            let mut cx = ViewContext::mutable(cx, handle.view_id);
 236            update(
 237                view.as_any_mut()
 238                    .downcast_mut()
 239                    .expect("downcast is type safe"),
 240                &mut cx,
 241            )
 242        })
 243        .expect("view is already on the stack")
 244    }
 245
 246    pub fn defer(&mut self, callback: impl 'static + FnOnce(&mut WindowContext)) {
 247        let window_id = self.window_id;
 248        self.app_context.defer(move |cx| {
 249            cx.update_window(window_id, |cx| callback(cx));
 250        })
 251    }
 252
 253    pub fn update_global<T, F, U>(&mut self, update: F) -> U
 254    where
 255        T: 'static,
 256        F: FnOnce(&mut T, &mut Self) -> U,
 257    {
 258        AppContext::update_global_internal(self, |global, cx| update(global, cx))
 259    }
 260
 261    pub fn update_default_global<T, F, U>(&mut self, update: F) -> U
 262    where
 263        T: 'static + Default,
 264        F: FnOnce(&mut T, &mut Self) -> U,
 265    {
 266        AppContext::update_default_global_internal(self, |global, cx| update(global, cx))
 267    }
 268
 269    pub fn subscribe<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
 270    where
 271        E: Entity,
 272        E::Event: 'static,
 273        H: Handle<E>,
 274        F: 'static + FnMut(H, &E::Event, &mut WindowContext),
 275    {
 276        self.subscribe_internal(handle, move |emitter, event, cx| {
 277            callback(emitter, event, cx);
 278            true
 279        })
 280    }
 281
 282    pub fn subscribe_internal<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
 283    where
 284        E: Entity,
 285        E::Event: 'static,
 286        H: Handle<E>,
 287        F: 'static + FnMut(H, &E::Event, &mut WindowContext) -> bool,
 288    {
 289        let window_id = self.window_id;
 290        self.app_context
 291            .subscribe_internal(handle, move |emitter, event, cx| {
 292                cx.update_window(window_id, |cx| callback(emitter, event, cx))
 293                    .unwrap_or(false)
 294            })
 295    }
 296
 297    pub(crate) fn observe_window_activation<F>(&mut self, callback: F) -> Subscription
 298    where
 299        F: 'static + FnMut(bool, &mut WindowContext) -> bool,
 300    {
 301        let window_id = self.window_id;
 302        let subscription_id = post_inc(&mut self.next_subscription_id);
 303        self.pending_effects
 304            .push_back(Effect::WindowActivationObservation {
 305                window_id,
 306                subscription_id,
 307                callback: Box::new(callback),
 308            });
 309        Subscription::WindowActivationObservation(
 310            self.window_activation_observations
 311                .subscribe(window_id, subscription_id),
 312        )
 313    }
 314
 315    pub(crate) fn observe_fullscreen<F>(&mut self, callback: F) -> Subscription
 316    where
 317        F: 'static + FnMut(bool, &mut WindowContext) -> bool,
 318    {
 319        let window_id = self.window_id;
 320        let subscription_id = post_inc(&mut self.next_subscription_id);
 321        self.pending_effects
 322            .push_back(Effect::WindowFullscreenObservation {
 323                window_id,
 324                subscription_id,
 325                callback: Box::new(callback),
 326            });
 327        Subscription::WindowActivationObservation(
 328            self.window_activation_observations
 329                .subscribe(window_id, subscription_id),
 330        )
 331    }
 332
 333    pub(crate) fn observe_window_bounds<F>(&mut self, callback: F) -> Subscription
 334    where
 335        F: 'static + FnMut(WindowBounds, Uuid, &mut WindowContext) -> bool,
 336    {
 337        let window_id = self.window_id;
 338        let subscription_id = post_inc(&mut self.next_subscription_id);
 339        self.pending_effects
 340            .push_back(Effect::WindowBoundsObservation {
 341                window_id,
 342                subscription_id,
 343                callback: Box::new(callback),
 344            });
 345        Subscription::WindowBoundsObservation(
 346            self.window_bounds_observations
 347                .subscribe(window_id, subscription_id),
 348        )
 349    }
 350
 351    pub fn observe_keystrokes<F>(&mut self, callback: F) -> Subscription
 352    where
 353        F: 'static
 354            + FnMut(&Keystroke, &MatchResult, Option<&Box<dyn Action>>, &mut WindowContext) -> bool,
 355    {
 356        let window_id = self.window_id;
 357        let subscription_id = post_inc(&mut self.next_subscription_id);
 358        self.keystroke_observations
 359            .add_callback(window_id, subscription_id, Box::new(callback));
 360        Subscription::KeystrokeObservation(
 361            self.keystroke_observations
 362                .subscribe(window_id, subscription_id),
 363        )
 364    }
 365
 366    pub(crate) fn available_actions(
 367        &self,
 368        view_id: usize,
 369    ) -> Vec<(&'static str, Box<dyn Action>, SmallVec<[Binding; 1]>)> {
 370        let window_id = self.window_id;
 371        let mut contexts = Vec::new();
 372        let mut handler_depths_by_action_id = HashMap::<TypeId, usize>::default();
 373        for (depth, view_id) in self.ancestors(view_id).enumerate() {
 374            if let Some(view_metadata) = self.views_metadata.get(&(window_id, view_id)) {
 375                contexts.push(view_metadata.keymap_context.clone());
 376                if let Some(actions) = self.actions.get(&view_metadata.type_id) {
 377                    handler_depths_by_action_id
 378                        .extend(actions.keys().copied().map(|action_id| (action_id, depth)));
 379                }
 380            } else {
 381                log::error!(
 382                    "view {} not found when computing available actions",
 383                    view_id
 384                );
 385            }
 386        }
 387
 388        handler_depths_by_action_id.extend(
 389            self.global_actions
 390                .keys()
 391                .copied()
 392                .map(|action_id| (action_id, contexts.len())),
 393        );
 394
 395        self.action_deserializers
 396            .iter()
 397            .filter_map(move |(name, (action_id, deserialize))| {
 398                if let Some(action_depth) = handler_depths_by_action_id.get(action_id).copied() {
 399                    let action = deserialize(serde_json::Value::Object(Default::default())).ok()?;
 400                    let bindings = self
 401                        .keystroke_matcher
 402                        .bindings_for_action(*action_id)
 403                        .filter(|b| {
 404                            action.eq(b.action())
 405                                && (0..=action_depth)
 406                                    .any(|depth| b.match_context(&contexts[depth..]))
 407                        })
 408                        .cloned()
 409                        .collect();
 410                    Some((*name, action, bindings))
 411                } else {
 412                    None
 413                }
 414            })
 415            .collect()
 416    }
 417
 418    pub(crate) fn dispatch_keystroke(&mut self, keystroke: &Keystroke) -> bool {
 419        let window_id = self.window_id;
 420        if let Some(focused_view_id) = self.focused_view_id() {
 421            let dispatch_path = self
 422                .ancestors(focused_view_id)
 423                .filter_map(|view_id| {
 424                    self.views_metadata
 425                        .get(&(window_id, view_id))
 426                        .map(|view| (view_id, view.keymap_context.clone()))
 427                })
 428                .collect();
 429
 430            let match_result = self
 431                .keystroke_matcher
 432                .push_keystroke(keystroke.clone(), dispatch_path);
 433            let mut handled_by = None;
 434
 435            let keystroke_handled = match &match_result {
 436                MatchResult::None => false,
 437                MatchResult::Pending => true,
 438                MatchResult::Matches(matches) => {
 439                    for (view_id, action) in matches {
 440                        if self.dispatch_action(Some(*view_id), action.as_ref()) {
 441                            self.keystroke_matcher.clear_pending();
 442                            handled_by = Some(action.boxed_clone());
 443                            break;
 444                        }
 445                    }
 446                    handled_by.is_some()
 447                }
 448            };
 449
 450            self.keystroke(
 451                window_id,
 452                keystroke.clone(),
 453                handled_by,
 454                match_result.clone(),
 455            );
 456            keystroke_handled
 457        } else {
 458            self.keystroke(window_id, keystroke.clone(), None, MatchResult::None);
 459            false
 460        }
 461    }
 462
 463    pub(crate) fn dispatch_event(&mut self, event: Event, event_reused: bool) -> bool {
 464        let mut mouse_events = SmallVec::<[_; 2]>::new();
 465        let mut notified_views: HashSet<usize> = Default::default();
 466        let window_id = self.window_id;
 467
 468        // 1. Handle platform event. Keyboard events get dispatched immediately, while mouse events
 469        //    get mapped into the mouse-specific MouseEvent type.
 470        //  -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
 471        //  -> Also updates mouse-related state
 472        match &event {
 473            Event::KeyDown(e) => return self.dispatch_key_down(e),
 474
 475            Event::KeyUp(e) => return self.dispatch_key_up(e),
 476
 477            Event::ModifiersChanged(e) => return self.dispatch_modifiers_changed(e),
 478
 479            Event::MouseDown(e) => {
 480                // Click events are weird because they can be fired after a drag event.
 481                // MDN says that browsers handle this by starting from 'the most
 482                // specific ancestor element that contained both [positions]'
 483                // So we need to store the overlapping regions on mouse down.
 484
 485                // If there is already region being clicked, don't replace it.
 486                if self.window.clicked_region.is_none() {
 487                    self.window.clicked_region_ids = self
 488                        .window
 489                        .mouse_regions
 490                        .iter()
 491                        .filter_map(|(region, _)| {
 492                            if region.bounds.contains_point(e.position) {
 493                                Some(region.id())
 494                            } else {
 495                                None
 496                            }
 497                        })
 498                        .collect();
 499
 500                    let mut highest_z_index = 0;
 501                    let mut clicked_region_id = None;
 502                    for (region, z_index) in self.window.mouse_regions.iter() {
 503                        if region.bounds.contains_point(e.position) && *z_index >= highest_z_index {
 504                            highest_z_index = *z_index;
 505                            clicked_region_id = Some(region.id());
 506                        }
 507                    }
 508
 509                    self.window.clicked_region =
 510                        clicked_region_id.map(|region_id| (region_id, e.button));
 511                }
 512
 513                mouse_events.push(MouseEvent::Down(MouseDown {
 514                    region: Default::default(),
 515                    platform_event: e.clone(),
 516                }));
 517                mouse_events.push(MouseEvent::DownOut(MouseDownOut {
 518                    region: Default::default(),
 519                    platform_event: e.clone(),
 520                }));
 521            }
 522
 523            Event::MouseUp(e) => {
 524                // NOTE: The order of event pushes is important! MouseUp events MUST be fired
 525                // before click events, and so the MouseUp events need to be pushed before
 526                // MouseClick events.
 527
 528                // Synthesize one last drag event to end the drag
 529                mouse_events.push(MouseEvent::Drag(MouseDrag {
 530                    region: Default::default(),
 531                    prev_mouse_position: self.window.mouse_position,
 532                    platform_event: MouseMovedEvent {
 533                        position: e.position,
 534                        pressed_button: Some(e.button),
 535                        modifiers: e.modifiers,
 536                    },
 537                    end: true,
 538                }));
 539                mouse_events.push(MouseEvent::Up(MouseUp {
 540                    region: Default::default(),
 541                    platform_event: e.clone(),
 542                }));
 543                mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 544                    region: Default::default(),
 545                    platform_event: e.clone(),
 546                }));
 547                mouse_events.push(MouseEvent::Click(MouseClick {
 548                    region: Default::default(),
 549                    platform_event: e.clone(),
 550                }));
 551                mouse_events.push(MouseEvent::ClickOut(MouseClickOut {
 552                    region: Default::default(),
 553                    platform_event: e.clone(),
 554                }));
 555            }
 556
 557            Event::MouseMoved(
 558                e @ MouseMovedEvent {
 559                    position,
 560                    pressed_button,
 561                    ..
 562                },
 563            ) => {
 564                let mut style_to_assign = CursorStyle::Arrow;
 565                for region in self.window.cursor_regions.iter().rev() {
 566                    if region.bounds.contains_point(*position) {
 567                        style_to_assign = region.style;
 568                        break;
 569                    }
 570                }
 571
 572                if self
 573                    .window
 574                    .platform_window
 575                    .is_topmost_for_position(*position)
 576                {
 577                    self.platform().set_cursor_style(style_to_assign);
 578                }
 579
 580                if !event_reused {
 581                    if pressed_button.is_some() {
 582                        mouse_events.push(MouseEvent::Drag(MouseDrag {
 583                            region: Default::default(),
 584                            prev_mouse_position: self.window.mouse_position,
 585                            platform_event: e.clone(),
 586                            end: false,
 587                        }));
 588                    } else if let Some((_, clicked_button)) = self.window.clicked_region {
 589                        mouse_events.push(MouseEvent::Drag(MouseDrag {
 590                            region: Default::default(),
 591                            prev_mouse_position: self.window.mouse_position,
 592                            platform_event: e.clone(),
 593                            end: true,
 594                        }));
 595
 596                        // Mouse up event happened outside the current window. Simulate mouse up button event
 597                        let button_event = e.to_button_event(clicked_button);
 598                        mouse_events.push(MouseEvent::Up(MouseUp {
 599                            region: Default::default(),
 600                            platform_event: button_event.clone(),
 601                        }));
 602                        mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 603                            region: Default::default(),
 604                            platform_event: button_event.clone(),
 605                        }));
 606                        mouse_events.push(MouseEvent::Click(MouseClick {
 607                            region: Default::default(),
 608                            platform_event: button_event.clone(),
 609                        }));
 610                    }
 611
 612                    mouse_events.push(MouseEvent::Move(MouseMove {
 613                        region: Default::default(),
 614                        platform_event: e.clone(),
 615                    }));
 616                }
 617
 618                mouse_events.push(MouseEvent::Hover(MouseHover {
 619                    region: Default::default(),
 620                    platform_event: e.clone(),
 621                    started: false,
 622                }));
 623                mouse_events.push(MouseEvent::MoveOut(MouseMoveOut {
 624                    region: Default::default(),
 625                }));
 626
 627                self.window.last_mouse_moved_event = Some(event.clone());
 628            }
 629
 630            Event::MouseExited(event) => {
 631                // When the platform sends a MouseExited event, synthesize
 632                // a MouseMoved event whose position is outside the window's
 633                // bounds so that hover and cursor state can be updated.
 634                return self.dispatch_event(
 635                    Event::MouseMoved(MouseMovedEvent {
 636                        position: event.position,
 637                        pressed_button: event.pressed_button,
 638                        modifiers: event.modifiers,
 639                    }),
 640                    event_reused,
 641                );
 642            }
 643
 644            Event::ScrollWheel(e) => mouse_events.push(MouseEvent::ScrollWheel(MouseScrollWheel {
 645                region: Default::default(),
 646                platform_event: e.clone(),
 647            })),
 648        }
 649
 650        if let Some(position) = event.position() {
 651            self.window.mouse_position = position;
 652        }
 653
 654        // 2. Dispatch mouse events on regions
 655        let mut any_event_handled = false;
 656        for mut mouse_event in mouse_events {
 657            let mut valid_regions = Vec::new();
 658
 659            // GPUI elements are arranged by z_index but sibling elements can register overlapping
 660            // mouse regions. As such, hover events are only fired on overlapping elements which
 661            // are at the same z-index as the topmost element which overlaps with the mouse.
 662            match &mouse_event {
 663                MouseEvent::Hover(_) => {
 664                    let mut highest_z_index = None;
 665                    let mouse_position = self.window.mouse_position.clone();
 666                    let window = &mut *self.window;
 667                    for (region, z_index) in window.mouse_regions.iter().rev() {
 668                        // Allow mouse regions to appear transparent to hovers
 669                        if !region.hoverable {
 670                            continue;
 671                        }
 672
 673                        let contains_mouse = region.bounds.contains_point(mouse_position);
 674
 675                        if contains_mouse && highest_z_index.is_none() {
 676                            highest_z_index = Some(z_index);
 677                        }
 678
 679                        // This unwrap relies on short circuiting boolean expressions
 680                        // The right side of the && is only executed when contains_mouse
 681                        // is true, and we know above that when contains_mouse is true
 682                        // highest_z_index is set.
 683                        if contains_mouse && z_index == highest_z_index.unwrap() {
 684                            //Ensure that hover entrance events aren't sent twice
 685                            if window.hovered_region_ids.insert(region.id()) {
 686                                valid_regions.push(region.clone());
 687                                if region.notify_on_hover {
 688                                    notified_views.insert(region.id().view_id());
 689                                }
 690                            }
 691                        } else {
 692                            // Ensure that hover exit events aren't sent twice
 693                            if window.hovered_region_ids.remove(&region.id()) {
 694                                valid_regions.push(region.clone());
 695                                if region.notify_on_hover {
 696                                    notified_views.insert(region.id().view_id());
 697                                }
 698                            }
 699                        }
 700                    }
 701                }
 702
 703                MouseEvent::Down(_) | MouseEvent::Up(_) => {
 704                    for (region, _) in self.window.mouse_regions.iter().rev() {
 705                        if region.bounds.contains_point(self.window.mouse_position) {
 706                            valid_regions.push(region.clone());
 707                            if region.notify_on_click {
 708                                notified_views.insert(region.id().view_id());
 709                            }
 710                        }
 711                    }
 712                }
 713
 714                MouseEvent::Click(e) => {
 715                    // Only raise click events if the released button is the same as the one stored
 716                    if self
 717                        .window
 718                        .clicked_region
 719                        .map(|(_, clicked_button)| clicked_button == e.button)
 720                        .unwrap_or(false)
 721                    {
 722                        // Clear clicked regions and clicked button
 723                        let clicked_region_ids = std::mem::replace(
 724                            &mut self.window.clicked_region_ids,
 725                            Default::default(),
 726                        );
 727                        self.window.clicked_region = None;
 728
 729                        // Find regions which still overlap with the mouse since the last MouseDown happened
 730                        for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 731                            if clicked_region_ids.contains(&mouse_region.id()) {
 732                                if mouse_region
 733                                    .bounds
 734                                    .contains_point(self.window.mouse_position)
 735                                {
 736                                    valid_regions.push(mouse_region.clone());
 737                                }
 738                            }
 739                        }
 740                    }
 741                }
 742
 743                MouseEvent::Drag(_) => {
 744                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 745                        if self.window.clicked_region_ids.contains(&mouse_region.id()) {
 746                            valid_regions.push(mouse_region.clone());
 747                        }
 748                    }
 749                }
 750
 751                MouseEvent::MoveOut(_)
 752                | MouseEvent::UpOut(_)
 753                | MouseEvent::DownOut(_)
 754                | MouseEvent::ClickOut(_) => {
 755                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 756                        // NOT contains
 757                        if !mouse_region
 758                            .bounds
 759                            .contains_point(self.window.mouse_position)
 760                        {
 761                            valid_regions.push(mouse_region.clone());
 762                        }
 763                    }
 764                }
 765
 766                _ => {
 767                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 768                        // Contains
 769                        if mouse_region
 770                            .bounds
 771                            .contains_point(self.window.mouse_position)
 772                        {
 773                            valid_regions.push(mouse_region.clone());
 774                        }
 775                    }
 776                }
 777            }
 778
 779            //3. Fire region events
 780            let hovered_region_ids = self.window.hovered_region_ids.clone();
 781            for valid_region in valid_regions.into_iter() {
 782                let mut handled = false;
 783                mouse_event.set_region(valid_region.bounds);
 784                if let MouseEvent::Hover(e) = &mut mouse_event {
 785                    e.started = hovered_region_ids.contains(&valid_region.id())
 786                }
 787                // Handle Down events if the MouseRegion has a Click or Drag handler. This makes the api more intuitive as you would
 788                // not expect a MouseRegion to be transparent to Down events if it also has a Click handler.
 789                // This behavior can be overridden by adding a Down handler
 790                if let MouseEvent::Down(e) = &mouse_event {
 791                    let has_click = valid_region
 792                        .handlers
 793                        .contains(MouseEvent::click_disc(), Some(e.button));
 794                    let has_drag = valid_region
 795                        .handlers
 796                        .contains(MouseEvent::drag_disc(), Some(e.button));
 797                    let has_down = valid_region
 798                        .handlers
 799                        .contains(MouseEvent::down_disc(), Some(e.button));
 800                    if !has_down && (has_click || has_drag) {
 801                        handled = true;
 802                    }
 803                }
 804
 805                // `event_consumed` should only be true if there are any handlers for this event.
 806                let mut event_consumed = handled;
 807                if let Some(callbacks) = valid_region.handlers.get(&mouse_event.handler_key()) {
 808                    for callback in callbacks {
 809                        handled = true;
 810                        let view_id = valid_region.id().view_id();
 811                        self.update_any_view(view_id, |view, cx| {
 812                            handled = callback(mouse_event.clone(), view.as_any_mut(), cx, view_id);
 813                        });
 814                        event_consumed |= handled;
 815                        any_event_handled |= handled;
 816                    }
 817                }
 818
 819                any_event_handled |= handled;
 820
 821                // For bubbling events, if the event was handled, don't continue dispatching.
 822                // This only makes sense for local events which return false from is_capturable.
 823                if event_consumed && mouse_event.is_capturable() {
 824                    break;
 825                }
 826            }
 827        }
 828
 829        for view_id in notified_views {
 830            self.notify_view(window_id, view_id);
 831        }
 832
 833        any_event_handled
 834    }
 835
 836    pub(crate) fn dispatch_key_down(&mut self, event: &KeyDownEvent) -> bool {
 837        let window_id = self.window_id;
 838        if let Some(focused_view_id) = self.window.focused_view_id {
 839            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 840                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 841                    let handled = view.key_down(event, self, view_id);
 842                    self.views.insert((window_id, view_id), view);
 843                    if handled {
 844                        return true;
 845                    }
 846                } else {
 847                    log::error!("view {} does not exist", view_id)
 848                }
 849            }
 850        }
 851
 852        false
 853    }
 854
 855    pub(crate) fn dispatch_key_up(&mut self, event: &KeyUpEvent) -> bool {
 856        let window_id = self.window_id;
 857        if let Some(focused_view_id) = self.window.focused_view_id {
 858            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 859                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 860                    let handled = view.key_up(event, self, view_id);
 861                    self.views.insert((window_id, view_id), view);
 862                    if handled {
 863                        return true;
 864                    }
 865                } else {
 866                    log::error!("view {} does not exist", view_id)
 867                }
 868            }
 869        }
 870
 871        false
 872    }
 873
 874    pub(crate) fn dispatch_modifiers_changed(&mut self, event: &ModifiersChangedEvent) -> bool {
 875        let window_id = self.window_id;
 876        if let Some(focused_view_id) = self.window.focused_view_id {
 877            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 878                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 879                    let handled = view.modifiers_changed(event, self, view_id);
 880                    self.views.insert((window_id, view_id), view);
 881                    if handled {
 882                        return true;
 883                    }
 884                } else {
 885                    log::error!("view {} does not exist", view_id)
 886                }
 887            }
 888        }
 889
 890        false
 891    }
 892
 893    pub fn invalidate(&mut self, mut invalidation: WindowInvalidation, appearance: Appearance) {
 894        self.start_frame();
 895        self.window.appearance = appearance;
 896        for view_id in &invalidation.removed {
 897            invalidation.updated.remove(view_id);
 898            self.window.rendered_views.remove(view_id);
 899        }
 900        for view_id in &invalidation.updated {
 901            let titlebar_height = self.window.titlebar_height;
 902            let element = self
 903                .render_view(RenderParams {
 904                    view_id: *view_id,
 905                    titlebar_height,
 906                    refreshing: false,
 907                    appearance,
 908                })
 909                .unwrap();
 910            self.window.rendered_views.insert(*view_id, element);
 911        }
 912    }
 913
 914    pub fn render_view(&mut self, params: RenderParams) -> Result<Box<dyn AnyRootElement>> {
 915        let window_id = self.window_id;
 916        let view_id = params.view_id;
 917        let mut view = self
 918            .views
 919            .remove(&(window_id, view_id))
 920            .ok_or_else(|| anyhow!("view not found"))?;
 921        let element = view.render(self, view_id);
 922        self.views.insert((window_id, view_id), view);
 923        Ok(element)
 924    }
 925
 926    pub(crate) fn layout(&mut self, refreshing: bool) -> Result<HashMap<usize, usize>> {
 927        let window_size = self.window.platform_window.content_size();
 928        let root_view_id = self.window.root_view().id();
 929        let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
 930        let mut new_parents = HashMap::default();
 931        let mut views_to_notify_if_ancestors_change = HashMap::default();
 932        rendered_root.layout(
 933            SizeConstraint::strict(window_size),
 934            &mut new_parents,
 935            &mut views_to_notify_if_ancestors_change,
 936            refreshing,
 937            self,
 938        )?;
 939
 940        for (view_id, view_ids_to_notify) in views_to_notify_if_ancestors_change {
 941            let mut current_view_id = view_id;
 942            loop {
 943                let old_parent_id = self.window.parents.get(&current_view_id);
 944                let new_parent_id = new_parents.get(&current_view_id);
 945                if old_parent_id.is_none() && new_parent_id.is_none() {
 946                    break;
 947                } else if old_parent_id == new_parent_id {
 948                    current_view_id = *old_parent_id.unwrap();
 949                } else {
 950                    let window_id = self.window_id;
 951                    for view_id_to_notify in view_ids_to_notify {
 952                        self.notify_view(window_id, view_id_to_notify);
 953                    }
 954                    break;
 955                }
 956            }
 957        }
 958
 959        let old_parents = mem::replace(&mut self.window.parents, new_parents);
 960        self.window
 961            .rendered_views
 962            .insert(root_view_id, rendered_root);
 963        Ok(old_parents)
 964    }
 965
 966    pub(crate) fn paint(&mut self) -> Result<Scene> {
 967        let window_size = self.window.platform_window.content_size();
 968        let scale_factor = self.window.platform_window.scale_factor();
 969
 970        let root_view_id = self.window.root_view().id();
 971        let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
 972
 973        let mut scene_builder = SceneBuilder::new(scale_factor);
 974        rendered_root.paint(
 975            &mut scene_builder,
 976            Vector2F::zero(),
 977            RectF::from_points(Vector2F::zero(), window_size),
 978            self,
 979        )?;
 980        self.window
 981            .rendered_views
 982            .insert(root_view_id, rendered_root);
 983
 984        self.window.text_layout_cache.finish_frame();
 985        let scene = scene_builder.build();
 986        self.window.cursor_regions = scene.cursor_regions();
 987        self.window.mouse_regions = scene.mouse_regions();
 988
 989        if self.window_is_active() {
 990            if let Some(event) = self.window.last_mouse_moved_event.clone() {
 991                self.dispatch_event(event, true);
 992            }
 993        }
 994
 995        Ok(scene)
 996    }
 997
 998    pub fn rect_for_text_range(&self, range_utf16: Range<usize>) -> Option<RectF> {
 999        let focused_view_id = self.window.focused_view_id?;
1000        self.window
1001            .rendered_views
1002            .get(&focused_view_id)?
1003            .rect_for_text_range(range_utf16, self)
1004            .log_err()
1005            .flatten()
1006    }
1007
1008    pub fn set_window_title(&mut self, title: &str) {
1009        self.window.platform_window.set_title(title);
1010    }
1011
1012    pub fn set_window_edited(&mut self, edited: bool) {
1013        self.window.platform_window.set_edited(edited);
1014    }
1015
1016    pub fn is_topmost_window_for_position(&self, position: Vector2F) -> bool {
1017        self.window
1018            .platform_window
1019            .is_topmost_for_position(position)
1020    }
1021
1022    pub fn activate_window(&self) {
1023        self.window.platform_window.activate();
1024    }
1025
1026    pub fn window_is_active(&self) -> bool {
1027        self.window.is_active
1028    }
1029
1030    pub fn window_is_fullscreen(&self) -> bool {
1031        self.window.is_fullscreen
1032    }
1033
1034    pub(crate) fn dispatch_action(&mut self, view_id: Option<usize>, action: &dyn Action) -> bool {
1035        if let Some(view_id) = view_id {
1036            self.halt_action_dispatch = false;
1037            self.visit_dispatch_path(view_id, |view_id, capture_phase, cx| {
1038                cx.update_any_view(view_id, |view, cx| {
1039                    let type_id = view.as_any().type_id();
1040                    if let Some((name, mut handlers)) = cx
1041                        .actions_mut(capture_phase)
1042                        .get_mut(&type_id)
1043                        .and_then(|h| h.remove_entry(&action.id()))
1044                    {
1045                        for handler in handlers.iter_mut().rev() {
1046                            cx.halt_action_dispatch = true;
1047                            handler(view, action, cx, view_id);
1048                            if cx.halt_action_dispatch {
1049                                break;
1050                            }
1051                        }
1052                        cx.actions_mut(capture_phase)
1053                            .get_mut(&type_id)
1054                            .unwrap()
1055                            .insert(name, handlers);
1056                    }
1057                });
1058
1059                !cx.halt_action_dispatch
1060            });
1061        }
1062
1063        if !self.halt_action_dispatch {
1064            self.halt_action_dispatch = self.dispatch_global_action_any(action);
1065        }
1066
1067        self.pending_effects
1068            .push_back(Effect::ActionDispatchNotification {
1069                action_id: action.id(),
1070            });
1071        self.halt_action_dispatch
1072    }
1073
1074    /// Returns an iterator over all of the view ids from the passed view up to the root of the window
1075    /// Includes the passed view itself
1076    pub(crate) fn ancestors(&self, mut view_id: usize) -> impl Iterator<Item = usize> + '_ {
1077        std::iter::once(view_id)
1078            .into_iter()
1079            .chain(std::iter::from_fn(move || {
1080                if let Some(parent_id) = self.window.parents.get(&view_id) {
1081                    view_id = *parent_id;
1082                    Some(view_id)
1083                } else {
1084                    None
1085                }
1086            }))
1087    }
1088
1089    // Traverses the parent tree. Walks down the tree toward the passed
1090    // view calling visit with true. Then walks back up the tree calling visit with false.
1091    // If `visit` returns false this function will immediately return.
1092    fn visit_dispatch_path(
1093        &mut self,
1094        view_id: usize,
1095        mut visit: impl FnMut(usize, bool, &mut WindowContext) -> bool,
1096    ) {
1097        // List of view ids from the leaf to the root of the window
1098        let path = self.ancestors(view_id).collect::<Vec<_>>();
1099
1100        // Walk down from the root to the leaf calling visit with capture_phase = true
1101        for view_id in path.iter().rev() {
1102            if !visit(*view_id, true, self) {
1103                return;
1104            }
1105        }
1106
1107        // Walk up from the leaf to the root calling visit with capture_phase = false
1108        for view_id in path.iter() {
1109            if !visit(*view_id, false, self) {
1110                return;
1111            }
1112        }
1113    }
1114
1115    pub fn focused_view_id(&self) -> Option<usize> {
1116        self.window.focused_view_id
1117    }
1118
1119    pub fn focus(&mut self, view_id: Option<usize>) {
1120        self.app_context.focus(self.window_id, view_id);
1121    }
1122
1123    pub fn window_bounds(&self) -> WindowBounds {
1124        self.window.platform_window.bounds()
1125    }
1126
1127    pub fn window_appearance(&self) -> Appearance {
1128        self.window.appearance
1129    }
1130
1131    pub fn window_display_uuid(&self) -> Option<Uuid> {
1132        self.window.platform_window.screen().display_uuid()
1133    }
1134
1135    pub fn show_character_palette(&self) {
1136        self.window.platform_window.show_character_palette();
1137    }
1138
1139    pub fn minimize_window(&self) {
1140        self.window.platform_window.minimize();
1141    }
1142
1143    pub fn zoom_window(&self) {
1144        self.window.platform_window.zoom();
1145    }
1146
1147    pub fn toggle_full_screen(&self) {
1148        self.window.platform_window.toggle_full_screen();
1149    }
1150
1151    pub fn prompt(
1152        &self,
1153        level: PromptLevel,
1154        msg: &str,
1155        answers: &[&str],
1156    ) -> oneshot::Receiver<usize> {
1157        self.window.platform_window.prompt(level, msg, answers)
1158    }
1159
1160    pub fn replace_root_view<V, F>(&mut self, build_root_view: F) -> WindowHandle<V>
1161    where
1162        V: View,
1163        F: FnOnce(&mut ViewContext<V>) -> V,
1164    {
1165        let root_view = self.add_view(|cx| build_root_view(cx));
1166        self.window.focused_view_id = Some(root_view.id());
1167        self.window.root_view = Some(root_view.into_any());
1168        WindowHandle::new(self.window_id)
1169    }
1170
1171    pub fn add_view<T, F>(&mut self, build_view: F) -> ViewHandle<T>
1172    where
1173        T: View,
1174        F: FnOnce(&mut ViewContext<T>) -> T,
1175    {
1176        self.add_option_view(|cx| Some(build_view(cx))).unwrap()
1177    }
1178
1179    pub fn add_option_view<T, F>(&mut self, build_view: F) -> Option<ViewHandle<T>>
1180    where
1181        T: View,
1182        F: FnOnce(&mut ViewContext<T>) -> Option<T>,
1183    {
1184        let window_id = self.window_id;
1185        let view_id = post_inc(&mut self.next_id);
1186        let mut cx = ViewContext::mutable(self, view_id);
1187        let handle = if let Some(view) = build_view(&mut cx) {
1188            let mut keymap_context = KeymapContext::default();
1189            view.update_keymap_context(&mut keymap_context, cx.app_context());
1190            self.views_metadata.insert(
1191                (window_id, view_id),
1192                ViewMetadata {
1193                    type_id: TypeId::of::<T>(),
1194                    keymap_context,
1195                },
1196            );
1197            self.views.insert((window_id, view_id), Box::new(view));
1198            self.window
1199                .invalidation
1200                .get_or_insert_with(Default::default)
1201                .updated
1202                .insert(view_id);
1203            Some(ViewHandle::new(window_id, view_id, &self.ref_counts))
1204        } else {
1205            None
1206        };
1207        handle
1208    }
1209}
1210
1211pub struct RenderParams {
1212    pub view_id: usize,
1213    pub titlebar_height: f32,
1214    pub refreshing: bool,
1215    pub appearance: Appearance,
1216}
1217
1218#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
1219pub enum Axis {
1220    #[default]
1221    Horizontal,
1222    Vertical,
1223}
1224
1225impl Axis {
1226    pub fn invert(self) -> Self {
1227        match self {
1228            Self::Horizontal => Self::Vertical,
1229            Self::Vertical => Self::Horizontal,
1230        }
1231    }
1232
1233    pub fn component(&self, point: Vector2F) -> f32 {
1234        match self {
1235            Self::Horizontal => point.x(),
1236            Self::Vertical => point.y(),
1237        }
1238    }
1239}
1240
1241impl ToJson for Axis {
1242    fn to_json(&self) -> serde_json::Value {
1243        match self {
1244            Axis::Horizontal => json!("horizontal"),
1245            Axis::Vertical => json!("vertical"),
1246        }
1247    }
1248}
1249
1250impl StaticColumnCount for Axis {}
1251impl Bind for Axis {
1252    fn bind(&self, statement: &Statement, start_index: i32) -> anyhow::Result<i32> {
1253        match self {
1254            Axis::Horizontal => "Horizontal",
1255            Axis::Vertical => "Vertical",
1256        }
1257        .bind(statement, start_index)
1258    }
1259}
1260
1261impl Column for Axis {
1262    fn column(statement: &mut Statement, start_index: i32) -> anyhow::Result<(Self, i32)> {
1263        String::column(statement, start_index).and_then(|(axis_text, next_index)| {
1264            Ok((
1265                match axis_text.as_str() {
1266                    "Horizontal" => Axis::Horizontal,
1267                    "Vertical" => Axis::Vertical,
1268                    _ => bail!("Stored serialized item kind is incorrect"),
1269                },
1270                next_index,
1271            ))
1272        })
1273    }
1274}
1275
1276pub trait Vector2FExt {
1277    fn along(self, axis: Axis) -> f32;
1278}
1279
1280impl Vector2FExt for Vector2F {
1281    fn along(self, axis: Axis) -> f32 {
1282        match axis {
1283            Axis::Horizontal => self.x(),
1284            Axis::Vertical => self.y(),
1285        }
1286    }
1287}
1288
1289pub trait RectFExt {
1290    fn length_along(self, axis: Axis) -> f32;
1291}
1292
1293impl RectFExt for RectF {
1294    fn length_along(self, axis: Axis) -> f32 {
1295        match axis {
1296            Axis::Horizontal => self.width(),
1297            Axis::Vertical => self.height(),
1298        }
1299    }
1300}
1301
1302#[derive(Copy, Clone, Debug)]
1303pub struct SizeConstraint {
1304    pub min: Vector2F,
1305    pub max: Vector2F,
1306}
1307
1308impl SizeConstraint {
1309    pub fn new(min: Vector2F, max: Vector2F) -> Self {
1310        Self { min, max }
1311    }
1312
1313    pub fn strict(size: Vector2F) -> Self {
1314        Self {
1315            min: size,
1316            max: size,
1317        }
1318    }
1319
1320    pub fn strict_along(axis: Axis, max: f32) -> Self {
1321        match axis {
1322            Axis::Horizontal => Self {
1323                min: vec2f(max, 0.0),
1324                max: vec2f(max, f32::INFINITY),
1325            },
1326            Axis::Vertical => Self {
1327                min: vec2f(0.0, max),
1328                max: vec2f(f32::INFINITY, max),
1329            },
1330        }
1331    }
1332
1333    pub fn max_along(&self, axis: Axis) -> f32 {
1334        match axis {
1335            Axis::Horizontal => self.max.x(),
1336            Axis::Vertical => self.max.y(),
1337        }
1338    }
1339
1340    pub fn min_along(&self, axis: Axis) -> f32 {
1341        match axis {
1342            Axis::Horizontal => self.min.x(),
1343            Axis::Vertical => self.min.y(),
1344        }
1345    }
1346
1347    pub fn constrain(&self, size: Vector2F) -> Vector2F {
1348        vec2f(
1349            size.x().min(self.max.x()).max(self.min.x()),
1350            size.y().min(self.max.y()).max(self.min.y()),
1351        )
1352    }
1353}
1354
1355impl Default for SizeConstraint {
1356    fn default() -> Self {
1357        SizeConstraint {
1358            min: Vector2F::zero(),
1359            max: Vector2F::splat(f32::INFINITY),
1360        }
1361    }
1362}
1363
1364impl ToJson for SizeConstraint {
1365    fn to_json(&self) -> serde_json::Value {
1366        json!({
1367            "min": self.min.to_json(),
1368            "max": self.max.to_json(),
1369        })
1370    }
1371}
1372
1373pub struct ChildView {
1374    view_id: usize,
1375    view_name: &'static str,
1376}
1377
1378impl ChildView {
1379    pub fn new(view: &AnyViewHandle, cx: &AppContext) -> Self {
1380        let view_name = cx.view_ui_name(view.window_id(), view.id()).unwrap();
1381        Self {
1382            view_id: view.id(),
1383            view_name,
1384        }
1385    }
1386}
1387
1388impl<V: View> Element<V> for ChildView {
1389    type LayoutState = ();
1390    type PaintState = ();
1391
1392    fn layout(
1393        &mut self,
1394        constraint: SizeConstraint,
1395        _: &mut V,
1396        cx: &mut LayoutContext<V>,
1397    ) -> (Vector2F, Self::LayoutState) {
1398        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1399            cx.new_parents.insert(self.view_id, cx.view_id());
1400            let size = rendered_view
1401                .layout(
1402                    constraint,
1403                    cx.new_parents,
1404                    cx.views_to_notify_if_ancestors_change,
1405                    cx.refreshing,
1406                    cx.view_context,
1407                )
1408                .log_err()
1409                .unwrap_or(Vector2F::zero());
1410            cx.window.rendered_views.insert(self.view_id, rendered_view);
1411            (size, ())
1412        } else {
1413            log::error!(
1414                "layout called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1415                self.view_id,
1416                self.view_name
1417            );
1418            (Vector2F::zero(), ())
1419        }
1420    }
1421
1422    fn paint(
1423        &mut self,
1424        scene: &mut SceneBuilder,
1425        bounds: RectF,
1426        visible_bounds: RectF,
1427        _: &mut Self::LayoutState,
1428        _: &mut V,
1429        cx: &mut ViewContext<V>,
1430    ) {
1431        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1432            rendered_view
1433                .paint(scene, bounds.origin(), visible_bounds, cx)
1434                .log_err();
1435            cx.window.rendered_views.insert(self.view_id, rendered_view);
1436        } else {
1437            log::error!(
1438                "paint called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1439                self.view_id,
1440                self.view_name
1441            );
1442        }
1443    }
1444
1445    fn rect_for_text_range(
1446        &self,
1447        range_utf16: Range<usize>,
1448        _: RectF,
1449        _: RectF,
1450        _: &Self::LayoutState,
1451        _: &Self::PaintState,
1452        _: &V,
1453        cx: &ViewContext<V>,
1454    ) -> Option<RectF> {
1455        if let Some(rendered_view) = cx.window.rendered_views.get(&self.view_id) {
1456            rendered_view
1457                .rect_for_text_range(range_utf16, &cx.window_context)
1458                .log_err()
1459                .flatten()
1460        } else {
1461            log::error!(
1462                "rect_for_text_range called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1463                self.view_id,
1464                self.view_name
1465            );
1466            None
1467        }
1468    }
1469
1470    fn debug(
1471        &self,
1472        bounds: RectF,
1473        _: &Self::LayoutState,
1474        _: &Self::PaintState,
1475        _: &V,
1476        cx: &ViewContext<V>,
1477    ) -> serde_json::Value {
1478        json!({
1479            "type": "ChildView",
1480            "bounds": bounds.to_json(),
1481            "child": if let Some(element) = cx.window.rendered_views.get(&self.view_id) {
1482                element.debug(&cx.window_context).log_err().unwrap_or_else(|| json!(null))
1483            } else {
1484                json!(null)
1485            }
1486        })
1487    }
1488}