window.rs

   1use crate::{
   2    elements::AnyRootElement,
   3    geometry::rect::RectF,
   4    json::{self, ToJson},
   5    keymap_matcher::{Binding, Keystroke, MatchResult},
   6    platform::{
   7        self, Appearance, CursorStyle, Event, KeyDownEvent, KeyUpEvent, ModifiersChangedEvent,
   8        MouseButton, MouseMovedEvent, PromptLevel, WindowBounds,
   9    },
  10    scene::{
  11        CursorRegion, MouseClick, MouseDown, MouseDownOut, MouseDrag, MouseEvent, MouseHover,
  12        MouseMove, MouseMoveOut, MouseScrollWheel, MouseUp, MouseUpOut, Scene,
  13    },
  14    text_layout::TextLayoutCache,
  15    util::post_inc,
  16    Action, AnyModelHandle, AnyView, AnyViewHandle, AnyWeakModelHandle, AnyWeakViewHandle,
  17    AppContext, Drawable, Effect, Entity, Handle, ModelContext, ModelHandle, MouseRegion,
  18    MouseRegionId, ParentId, ReadModel, ReadView, SceneBuilder, Subscription, UpdateModel,
  19    UpdateView, UpgradeModelHandle, UpgradeViewHandle, View, ViewContext, ViewHandle,
  20    WeakModelHandle, WeakViewHandle, WindowInvalidation,
  21};
  22use anyhow::{anyhow, bail, Result};
  23use collections::{HashMap, HashSet};
  24use pathfinder_geometry::vector::{vec2f, Vector2F};
  25use postage::oneshot;
  26use serde_json::json;
  27use smallvec::SmallVec;
  28use sqlez::{
  29    bindable::{Bind, Column, StaticColumnCount},
  30    statement::Statement,
  31};
  32use std::{
  33    any::TypeId,
  34    ops::{Deref, DerefMut, Range},
  35};
  36use util::ResultExt;
  37use uuid::Uuid;
  38
  39use super::Reference;
  40
  41pub struct Window {
  42    pub(crate) root_view: Option<AnyViewHandle>,
  43    pub(crate) focused_view_id: Option<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            is_active: false,
  78            invalidation: None,
  79            is_fullscreen: false,
  80            platform_window,
  81            rendered_views: Default::default(),
  82            cursor_regions: Default::default(),
  83            mouse_regions: Default::default(),
  84            text_layout_cache: TextLayoutCache::new(cx.font_system.clone()),
  85            last_mouse_moved_event: None,
  86            hovered_region_ids: Default::default(),
  87            clicked_region_ids: Default::default(),
  88            clicked_button: None,
  89            mouse_position: vec2f(0., 0.),
  90            titlebar_height,
  91            appearance,
  92        };
  93
  94        let mut window_context = WindowContext::mutable(cx, &mut window, window_id);
  95        let root_view = window_context
  96            .build_and_insert_view(ParentId::Root, |cx| Some(build_view(cx)))
  97            .unwrap();
  98        if let Some(mut invalidation) = window_context.window.invalidation.take() {
  99            window_context.invalidate(&mut invalidation, appearance);
 100        }
 101        window.focused_view_id = Some(root_view.id());
 102        window.root_view = Some(root_view.into_any());
 103        window
 104    }
 105
 106    pub fn root_view(&self) -> &AnyViewHandle {
 107        &self
 108            .root_view
 109            .as_ref()
 110            .expect("root_view called during window construction")
 111    }
 112}
 113
 114pub struct WindowContext<'a: 'b, 'b> {
 115    pub(crate) app_context: Reference<'a, AppContext>,
 116    pub(crate) window: Reference<'b, Window>,
 117    pub(crate) window_id: usize,
 118    pub(crate) refreshing: bool,
 119}
 120
 121impl Deref for WindowContext<'_, '_> {
 122    type Target = AppContext;
 123
 124    fn deref(&self) -> &Self::Target {
 125        &self.app_context
 126    }
 127}
 128
 129impl DerefMut for WindowContext<'_, '_> {
 130    fn deref_mut(&mut self) -> &mut Self::Target {
 131        &mut self.app_context
 132    }
 133}
 134
 135impl ReadModel for WindowContext<'_, '_> {
 136    fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
 137        self.app_context.read_model(handle)
 138    }
 139}
 140
 141impl UpdateModel for WindowContext<'_, '_> {
 142    fn update_model<T: Entity, R>(
 143        &mut self,
 144        handle: &ModelHandle<T>,
 145        update: &mut dyn FnMut(&mut T, &mut ModelContext<T>) -> R,
 146    ) -> R {
 147        self.app_context.update_model(handle, update)
 148    }
 149}
 150
 151impl ReadView for WindowContext<'_, '_> {
 152    fn read_view<W: View>(&self, handle: &crate::ViewHandle<W>) -> &W {
 153        self.app_context.read_view(handle)
 154    }
 155}
 156
 157impl UpdateView for WindowContext<'_, '_> {
 158    type Output<S> = S;
 159
 160    fn update_view<T, S>(
 161        &mut self,
 162        handle: &ViewHandle<T>,
 163        update: &mut dyn FnMut(&mut T, &mut ViewContext<T>) -> S,
 164    ) -> S
 165    where
 166        T: View,
 167    {
 168        self.update_any_view(handle.view_id, |view, cx| {
 169            let mut cx = ViewContext::mutable(cx, handle.view_id);
 170            update(
 171                view.as_any_mut()
 172                    .downcast_mut()
 173                    .expect("downcast is type safe"),
 174                &mut cx,
 175            )
 176        })
 177        .unwrap()
 178    }
 179}
 180
 181impl UpgradeModelHandle for WindowContext<'_, '_> {
 182    fn upgrade_model_handle<T: Entity>(
 183        &self,
 184        handle: &WeakModelHandle<T>,
 185    ) -> Option<ModelHandle<T>> {
 186        self.app_context.upgrade_model_handle(handle)
 187    }
 188
 189    fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
 190        self.app_context.model_handle_is_upgradable(handle)
 191    }
 192
 193    fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
 194        self.app_context.upgrade_any_model_handle(handle)
 195    }
 196}
 197
 198impl UpgradeViewHandle for WindowContext<'_, '_> {
 199    fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
 200        self.app_context.upgrade_view_handle(handle)
 201    }
 202
 203    fn upgrade_any_view_handle(&self, handle: &AnyWeakViewHandle) -> Option<AnyViewHandle> {
 204        self.app_context.upgrade_any_view_handle(handle)
 205    }
 206}
 207
 208impl<'a: 'b, 'b> WindowContext<'a, 'b> {
 209    pub fn mutable(
 210        app_context: &'a mut AppContext,
 211        window: &'b mut Window,
 212        window_id: usize,
 213    ) -> Self {
 214        Self {
 215            app_context: Reference::Mutable(app_context),
 216            window: Reference::Mutable(window),
 217            window_id,
 218            refreshing: false,
 219        }
 220    }
 221
 222    pub fn immutable(app_context: &'a AppContext, window: &'b Window, window_id: usize) -> Self {
 223        Self {
 224            app_context: Reference::Immutable(app_context),
 225            window: Reference::Immutable(window),
 226            window_id,
 227            refreshing: false,
 228        }
 229    }
 230
 231    pub fn window_id(&self) -> usize {
 232        self.window_id
 233    }
 234
 235    pub fn app_context(&mut self) -> &mut AppContext {
 236        &mut self.app_context
 237    }
 238
 239    pub fn root_view(&self) -> &AnyViewHandle {
 240        self.window.root_view()
 241    }
 242
 243    pub fn window_size(&self) -> Vector2F {
 244        self.window.platform_window.content_size()
 245    }
 246
 247    pub fn text_layout_cache(&self) -> &TextLayoutCache {
 248        &self.window.text_layout_cache
 249    }
 250
 251    pub(crate) fn update_any_view<F, T>(&mut self, view_id: usize, f: F) -> Option<T>
 252    where
 253        F: FnOnce(&mut dyn AnyView, &mut Self) -> T,
 254    {
 255        let window_id = self.window_id;
 256        let mut view = self.views.remove(&(window_id, view_id))?;
 257        let result = f(view.as_mut(), self);
 258        self.views.insert((window_id, view_id), view);
 259        Some(result)
 260    }
 261
 262    pub fn defer(&mut self, callback: impl 'static + FnOnce(&mut WindowContext)) {
 263        let window_id = self.window_id;
 264        self.app_context.defer(move |cx| {
 265            cx.update_window(window_id, |cx| callback(cx));
 266        })
 267    }
 268
 269    pub fn update_global<T, F, U>(&mut self, update: F) -> U
 270    where
 271        T: 'static,
 272        F: FnOnce(&mut T, &mut Self) -> U,
 273    {
 274        AppContext::update_global_internal(self, |global, cx| update(global, cx))
 275    }
 276
 277    pub fn update_default_global<T, F, U>(&mut self, update: F) -> U
 278    where
 279        T: 'static + Default,
 280        F: FnOnce(&mut T, &mut Self) -> U,
 281    {
 282        AppContext::update_default_global_internal(self, |global, cx| update(global, cx))
 283    }
 284
 285    pub fn subscribe<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
 286    where
 287        E: Entity,
 288        E::Event: 'static,
 289        H: Handle<E>,
 290        F: 'static + FnMut(H, &E::Event, &mut WindowContext),
 291    {
 292        self.subscribe_internal(handle, move |emitter, event, cx| {
 293            callback(emitter, event, cx);
 294            true
 295        })
 296    }
 297
 298    pub fn subscribe_internal<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
 299    where
 300        E: Entity,
 301        E::Event: 'static,
 302        H: Handle<E>,
 303        F: 'static + FnMut(H, &E::Event, &mut WindowContext) -> bool,
 304    {
 305        let window_id = self.window_id;
 306        self.app_context
 307            .subscribe_internal(handle, move |emitter, event, cx| {
 308                cx.update_window(window_id, |cx| callback(emitter, event, cx))
 309                    .unwrap_or(false)
 310            })
 311    }
 312
 313    pub(crate) fn observe_window_activation<F>(&mut self, callback: F) -> Subscription
 314    where
 315        F: 'static + FnMut(bool, &mut WindowContext) -> bool,
 316    {
 317        let window_id = self.window_id;
 318        let subscription_id = post_inc(&mut self.next_subscription_id);
 319        self.pending_effects
 320            .push_back(Effect::WindowActivationObservation {
 321                window_id,
 322                subscription_id,
 323                callback: Box::new(callback),
 324            });
 325        Subscription::WindowActivationObservation(
 326            self.window_activation_observations
 327                .subscribe(window_id, subscription_id),
 328        )
 329    }
 330
 331    pub(crate) fn observe_fullscreen<F>(&mut self, callback: F) -> Subscription
 332    where
 333        F: 'static + FnMut(bool, &mut WindowContext) -> bool,
 334    {
 335        let window_id = self.window_id;
 336        let subscription_id = post_inc(&mut self.next_subscription_id);
 337        self.pending_effects
 338            .push_back(Effect::WindowFullscreenObservation {
 339                window_id,
 340                subscription_id,
 341                callback: Box::new(callback),
 342            });
 343        Subscription::WindowActivationObservation(
 344            self.window_activation_observations
 345                .subscribe(window_id, subscription_id),
 346        )
 347    }
 348
 349    pub(crate) fn observe_window_bounds<F>(&mut self, callback: F) -> Subscription
 350    where
 351        F: 'static + FnMut(WindowBounds, Uuid, &mut WindowContext) -> bool,
 352    {
 353        let window_id = self.window_id;
 354        let subscription_id = post_inc(&mut self.next_subscription_id);
 355        self.pending_effects
 356            .push_back(Effect::WindowBoundsObservation {
 357                window_id,
 358                subscription_id,
 359                callback: Box::new(callback),
 360            });
 361        Subscription::WindowBoundsObservation(
 362            self.window_bounds_observations
 363                .subscribe(window_id, subscription_id),
 364        )
 365    }
 366
 367    pub fn observe_keystrokes<F>(&mut self, callback: F) -> Subscription
 368    where
 369        F: 'static
 370            + FnMut(&Keystroke, &MatchResult, Option<&Box<dyn Action>>, &mut WindowContext) -> bool,
 371    {
 372        let window_id = self.window_id;
 373        let subscription_id = post_inc(&mut self.next_subscription_id);
 374        self.keystroke_observations
 375            .add_callback(window_id, subscription_id, Box::new(callback));
 376        Subscription::KeystrokeObservation(
 377            self.keystroke_observations
 378                .subscribe(window_id, subscription_id),
 379        )
 380    }
 381
 382    /// Return keystrokes that would dispatch the given action on the given view.
 383    pub(crate) fn keystrokes_for_action(
 384        &mut self,
 385        view_id: usize,
 386        action: &dyn Action,
 387    ) -> Option<SmallVec<[Keystroke; 2]>> {
 388        let window_id = self.window_id;
 389        let mut contexts = Vec::new();
 390        let mut handler_depth = None;
 391        for (i, view_id) in self.ancestors(view_id).enumerate() {
 392            if let Some(view) = self.views.get(&(window_id, view_id)) {
 393                if let Some(actions) = self.actions.get(&view.as_any().type_id()) {
 394                    if actions.contains_key(&action.as_any().type_id()) {
 395                        handler_depth = Some(i);
 396                    }
 397                }
 398                contexts.push(view.keymap_context(self));
 399            }
 400        }
 401
 402        if self.global_actions.contains_key(&action.as_any().type_id()) {
 403            handler_depth = Some(contexts.len())
 404        }
 405
 406        self.keystroke_matcher
 407            .bindings_for_action_type(action.as_any().type_id())
 408            .find_map(|b| {
 409                handler_depth
 410                    .map(|highest_handler| {
 411                        if (0..=highest_handler).any(|depth| b.match_context(&contexts[depth..])) {
 412                            Some(b.keystrokes().into())
 413                        } else {
 414                            None
 415                        }
 416                    })
 417                    .flatten()
 418            })
 419    }
 420
 421    pub fn available_actions(
 422        &self,
 423        view_id: usize,
 424    ) -> impl Iterator<Item = (&'static str, Box<dyn Action>, SmallVec<[&Binding; 1]>)> {
 425        let window_id = self.window_id;
 426        let mut contexts = Vec::new();
 427        let mut handler_depths_by_action_type = HashMap::<TypeId, usize>::default();
 428        for (depth, view_id) in self.ancestors(view_id).enumerate() {
 429            if let Some(view) = self.views.get(&(window_id, view_id)) {
 430                contexts.push(view.keymap_context(self));
 431                let view_type = view.as_any().type_id();
 432                if let Some(actions) = self.actions.get(&view_type) {
 433                    handler_depths_by_action_type.extend(
 434                        actions
 435                            .keys()
 436                            .copied()
 437                            .map(|action_type| (action_type, depth)),
 438                    );
 439                }
 440            }
 441        }
 442
 443        handler_depths_by_action_type.extend(
 444            self.global_actions
 445                .keys()
 446                .copied()
 447                .map(|action_type| (action_type, contexts.len())),
 448        );
 449
 450        self.action_deserializers
 451            .iter()
 452            .filter_map(move |(name, (type_id, deserialize))| {
 453                if let Some(action_depth) = handler_depths_by_action_type.get(type_id).copied() {
 454                    Some((
 455                        *name,
 456                        deserialize("{}").ok()?,
 457                        self.keystroke_matcher
 458                            .bindings_for_action_type(*type_id)
 459                            .filter(|b| {
 460                                (0..=action_depth).any(|depth| b.match_context(&contexts[depth..]))
 461                            })
 462                            .collect(),
 463                    ))
 464                } else {
 465                    None
 466                }
 467            })
 468    }
 469
 470    pub fn dispatch_keystroke(&mut self, keystroke: &Keystroke) -> bool {
 471        let window_id = self.window_id;
 472        if let Some(focused_view_id) = self.focused_view_id() {
 473            let dispatch_path = self
 474                .ancestors(focused_view_id)
 475                .filter_map(|view_id| {
 476                    self.views
 477                        .get(&(window_id, view_id))
 478                        .map(|view| (view_id, view.keymap_context(self)))
 479                })
 480                .collect();
 481
 482            let match_result = self
 483                .keystroke_matcher
 484                .push_keystroke(keystroke.clone(), dispatch_path);
 485            let mut handled_by = None;
 486
 487            let keystroke_handled = match &match_result {
 488                MatchResult::None => false,
 489                MatchResult::Pending => true,
 490                MatchResult::Matches(matches) => {
 491                    for (view_id, action) in matches {
 492                        if self.handle_dispatch_action_from_effect(Some(*view_id), action.as_ref())
 493                        {
 494                            self.keystroke_matcher.clear_pending();
 495                            handled_by = Some(action.boxed_clone());
 496                            break;
 497                        }
 498                    }
 499                    handled_by.is_some()
 500                }
 501            };
 502
 503            self.keystroke(
 504                window_id,
 505                keystroke.clone(),
 506                handled_by,
 507                match_result.clone(),
 508            );
 509            keystroke_handled
 510        } else {
 511            self.keystroke(window_id, keystroke.clone(), None, MatchResult::None);
 512            false
 513        }
 514    }
 515
 516    pub fn dispatch_event(&mut self, event: Event, event_reused: bool) -> bool {
 517        let mut mouse_events = SmallVec::<[_; 2]>::new();
 518        let mut notified_views: HashSet<usize> = Default::default();
 519        let window_id = self.window_id;
 520
 521        // 1. Handle platform event. Keyboard events get dispatched immediately, while mouse events
 522        //    get mapped into the mouse-specific MouseEvent type.
 523        //  -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
 524        //  -> Also updates mouse-related state
 525        match &event {
 526            Event::KeyDown(e) => return self.dispatch_key_down(e),
 527
 528            Event::KeyUp(e) => return self.dispatch_key_up(e),
 529
 530            Event::ModifiersChanged(e) => return self.dispatch_modifiers_changed(e),
 531
 532            Event::MouseDown(e) => {
 533                // Click events are weird because they can be fired after a drag event.
 534                // MDN says that browsers handle this by starting from 'the most
 535                // specific ancestor element that contained both [positions]'
 536                // So we need to store the overlapping regions on mouse down.
 537
 538                // If there is already clicked_button stored, don't replace it.
 539                if self.window.clicked_button.is_none() {
 540                    self.window.clicked_region_ids = self
 541                        .window
 542                        .mouse_regions
 543                        .iter()
 544                        .filter_map(|(region, _)| {
 545                            if region.bounds.contains_point(e.position) {
 546                                Some(region.id())
 547                            } else {
 548                                None
 549                            }
 550                        })
 551                        .collect();
 552
 553                    self.window.clicked_button = Some(e.button);
 554                }
 555
 556                mouse_events.push(MouseEvent::Down(MouseDown {
 557                    region: Default::default(),
 558                    platform_event: e.clone(),
 559                }));
 560                mouse_events.push(MouseEvent::DownOut(MouseDownOut {
 561                    region: Default::default(),
 562                    platform_event: e.clone(),
 563                }));
 564            }
 565
 566            Event::MouseUp(e) => {
 567                // NOTE: The order of event pushes is important! MouseUp events MUST be fired
 568                // before click events, and so the MouseUp events need to be pushed before
 569                // MouseClick events.
 570                mouse_events.push(MouseEvent::Up(MouseUp {
 571                    region: Default::default(),
 572                    platform_event: e.clone(),
 573                }));
 574                mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 575                    region: Default::default(),
 576                    platform_event: e.clone(),
 577                }));
 578                mouse_events.push(MouseEvent::Click(MouseClick {
 579                    region: Default::default(),
 580                    platform_event: e.clone(),
 581                }));
 582            }
 583
 584            Event::MouseMoved(
 585                e @ MouseMovedEvent {
 586                    position,
 587                    pressed_button,
 588                    ..
 589                },
 590            ) => {
 591                let mut style_to_assign = CursorStyle::Arrow;
 592                for region in self.window.cursor_regions.iter().rev() {
 593                    if region.bounds.contains_point(*position) {
 594                        style_to_assign = region.style;
 595                        break;
 596                    }
 597                }
 598
 599                if self
 600                    .window
 601                    .platform_window
 602                    .is_topmost_for_position(*position)
 603                {
 604                    self.platform().set_cursor_style(style_to_assign);
 605                }
 606
 607                if !event_reused {
 608                    if pressed_button.is_some() {
 609                        mouse_events.push(MouseEvent::Drag(MouseDrag {
 610                            region: Default::default(),
 611                            prev_mouse_position: self.window.mouse_position,
 612                            platform_event: e.clone(),
 613                        }));
 614                    } else if let Some(clicked_button) = self.window.clicked_button {
 615                        // Mouse up event happened outside the current window. Simulate mouse up button event
 616                        let button_event = e.to_button_event(clicked_button);
 617                        mouse_events.push(MouseEvent::Up(MouseUp {
 618                            region: Default::default(),
 619                            platform_event: button_event.clone(),
 620                        }));
 621                        mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 622                            region: Default::default(),
 623                            platform_event: button_event.clone(),
 624                        }));
 625                        mouse_events.push(MouseEvent::Click(MouseClick {
 626                            region: Default::default(),
 627                            platform_event: button_event.clone(),
 628                        }));
 629                    }
 630
 631                    mouse_events.push(MouseEvent::Move(MouseMove {
 632                        region: Default::default(),
 633                        platform_event: e.clone(),
 634                    }));
 635                }
 636
 637                mouse_events.push(MouseEvent::Hover(MouseHover {
 638                    region: Default::default(),
 639                    platform_event: e.clone(),
 640                    started: false,
 641                }));
 642                mouse_events.push(MouseEvent::MoveOut(MouseMoveOut {
 643                    region: Default::default(),
 644                }));
 645
 646                self.window.last_mouse_moved_event = Some(event.clone());
 647            }
 648
 649            Event::MouseExited(event) => {
 650                // When the platform sends a MouseExited event, synthesize
 651                // a MouseMoved event whose position is outside the window's
 652                // bounds so that hover and cursor state can be updated.
 653                return self.dispatch_event(
 654                    Event::MouseMoved(MouseMovedEvent {
 655                        position: event.position,
 656                        pressed_button: event.pressed_button,
 657                        modifiers: event.modifiers,
 658                    }),
 659                    event_reused,
 660                );
 661            }
 662
 663            Event::ScrollWheel(e) => mouse_events.push(MouseEvent::ScrollWheel(MouseScrollWheel {
 664                region: Default::default(),
 665                platform_event: e.clone(),
 666            })),
 667        }
 668
 669        if let Some(position) = event.position() {
 670            self.window.mouse_position = position;
 671        }
 672
 673        // 2. Dispatch mouse events on regions
 674        let mut any_event_handled = false;
 675        for mut mouse_event in mouse_events {
 676            let mut valid_regions = Vec::new();
 677
 678            // GPUI elements are arranged by z_index but sibling elements can register overlapping
 679            // mouse regions. As such, hover events are only fired on overlapping elements which
 680            // are at the same z-index as the topmost element which overlaps with the mouse.
 681            match &mouse_event {
 682                MouseEvent::Hover(_) => {
 683                    let mut highest_z_index = None;
 684                    let mouse_position = self.window.mouse_position.clone();
 685                    let window = &mut *self.window;
 686                    for (region, z_index) in window.mouse_regions.iter().rev() {
 687                        // Allow mouse regions to appear transparent to hovers
 688                        if !region.hoverable {
 689                            continue;
 690                        }
 691
 692                        let contains_mouse = region.bounds.contains_point(mouse_position);
 693
 694                        if contains_mouse && highest_z_index.is_none() {
 695                            highest_z_index = Some(z_index);
 696                        }
 697
 698                        // This unwrap relies on short circuiting boolean expressions
 699                        // The right side of the && is only executed when contains_mouse
 700                        // is true, and we know above that when contains_mouse is true
 701                        // highest_z_index is set.
 702                        if contains_mouse && z_index == highest_z_index.unwrap() {
 703                            //Ensure that hover entrance events aren't sent twice
 704                            if window.hovered_region_ids.insert(region.id()) {
 705                                valid_regions.push(region.clone());
 706                                if region.notify_on_hover {
 707                                    notified_views.insert(region.id().view_id());
 708                                }
 709                            }
 710                        } else {
 711                            // Ensure that hover exit events aren't sent twice
 712                            if window.hovered_region_ids.remove(&region.id()) {
 713                                valid_regions.push(region.clone());
 714                                if region.notify_on_hover {
 715                                    notified_views.insert(region.id().view_id());
 716                                }
 717                            }
 718                        }
 719                    }
 720                }
 721
 722                MouseEvent::Down(_) | MouseEvent::Up(_) => {
 723                    for (region, _) in self.window.mouse_regions.iter().rev() {
 724                        if region.bounds.contains_point(self.window.mouse_position) {
 725                            valid_regions.push(region.clone());
 726                            if region.notify_on_click {
 727                                notified_views.insert(region.id().view_id());
 728                            }
 729                        }
 730                    }
 731                }
 732
 733                MouseEvent::Click(e) => {
 734                    // Only raise click events if the released button is the same as the one stored
 735                    if self
 736                        .window
 737                        .clicked_button
 738                        .map(|clicked_button| clicked_button == e.button)
 739                        .unwrap_or(false)
 740                    {
 741                        // Clear clicked regions and clicked button
 742                        let clicked_region_ids = std::mem::replace(
 743                            &mut self.window.clicked_region_ids,
 744                            Default::default(),
 745                        );
 746                        self.window.clicked_button = None;
 747
 748                        // Find regions which still overlap with the mouse since the last MouseDown happened
 749                        for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 750                            if clicked_region_ids.contains(&mouse_region.id()) {
 751                                if mouse_region
 752                                    .bounds
 753                                    .contains_point(self.window.mouse_position)
 754                                {
 755                                    valid_regions.push(mouse_region.clone());
 756                                }
 757                            }
 758                        }
 759                    }
 760                }
 761
 762                MouseEvent::Drag(_) => {
 763                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 764                        if self.window.clicked_region_ids.contains(&mouse_region.id()) {
 765                            valid_regions.push(mouse_region.clone());
 766                        }
 767                    }
 768                }
 769
 770                MouseEvent::MoveOut(_) | MouseEvent::UpOut(_) | MouseEvent::DownOut(_) => {
 771                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 772                        // NOT contains
 773                        if !mouse_region
 774                            .bounds
 775                            .contains_point(self.window.mouse_position)
 776                        {
 777                            valid_regions.push(mouse_region.clone());
 778                        }
 779                    }
 780                }
 781
 782                _ => {
 783                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 784                        // Contains
 785                        if mouse_region
 786                            .bounds
 787                            .contains_point(self.window.mouse_position)
 788                        {
 789                            valid_regions.push(mouse_region.clone());
 790                        }
 791                    }
 792                }
 793            }
 794
 795            //3. Fire region events
 796            let hovered_region_ids = self.window.hovered_region_ids.clone();
 797            for valid_region in valid_regions.into_iter() {
 798                let mut handled = false;
 799                mouse_event.set_region(valid_region.bounds);
 800                if let MouseEvent::Hover(e) = &mut mouse_event {
 801                    e.started = hovered_region_ids.contains(&valid_region.id())
 802                }
 803                // Handle Down events if the MouseRegion has a Click or Drag handler. This makes the api more intuitive as you would
 804                // not expect a MouseRegion to be transparent to Down events if it also has a Click handler.
 805                // This behavior can be overridden by adding a Down handler
 806                if let MouseEvent::Down(e) = &mouse_event {
 807                    let has_click = valid_region
 808                        .handlers
 809                        .contains(MouseEvent::click_disc(), Some(e.button));
 810                    let has_drag = valid_region
 811                        .handlers
 812                        .contains(MouseEvent::drag_disc(), Some(e.button));
 813                    let has_down = valid_region
 814                        .handlers
 815                        .contains(MouseEvent::down_disc(), Some(e.button));
 816                    if !has_down && (has_click || has_drag) {
 817                        handled = true;
 818                    }
 819                }
 820
 821                // `event_consumed` should only be true if there are any handlers for this event.
 822                let mut event_consumed = handled;
 823                if let Some(callbacks) = valid_region.handlers.get(&mouse_event.handler_key()) {
 824                    for callback in callbacks {
 825                        handled = true;
 826                        let view_id = valid_region.id().view_id();
 827                        self.update_any_view(view_id, |view, cx| {
 828                            handled = callback(mouse_event.clone(), view.as_any_mut(), cx, view_id);
 829                        });
 830                        event_consumed |= handled;
 831                        any_event_handled |= handled;
 832                    }
 833                }
 834
 835                any_event_handled |= handled;
 836
 837                // For bubbling events, if the event was handled, don't continue dispatching.
 838                // This only makes sense for local events which return false from is_capturable.
 839                if event_consumed && mouse_event.is_capturable() {
 840                    break;
 841                }
 842            }
 843        }
 844
 845        for view_id in notified_views {
 846            self.notify_view(window_id, view_id);
 847        }
 848
 849        any_event_handled
 850    }
 851
 852    pub fn dispatch_key_down(&mut self, event: &KeyDownEvent) -> bool {
 853        let window_id = self.window_id;
 854        if let Some(focused_view_id) = self.window.focused_view_id {
 855            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 856                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 857                    let handled = view.key_down(event, self, view_id);
 858                    self.views.insert((window_id, view_id), view);
 859                    if handled {
 860                        return true;
 861                    }
 862                } else {
 863                    log::error!("view {} does not exist", view_id)
 864                }
 865            }
 866        }
 867
 868        false
 869    }
 870
 871    pub fn dispatch_key_up(&mut self, event: &KeyUpEvent) -> bool {
 872        let window_id = self.window_id;
 873        if let Some(focused_view_id) = self.window.focused_view_id {
 874            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 875                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 876                    let handled = view.key_up(event, self, view_id);
 877                    self.views.insert((window_id, view_id), view);
 878                    if handled {
 879                        return true;
 880                    }
 881                } else {
 882                    log::error!("view {} does not exist", view_id)
 883                }
 884            }
 885        }
 886
 887        false
 888    }
 889
 890    pub fn dispatch_modifiers_changed(&mut self, event: &ModifiersChangedEvent) -> bool {
 891        let window_id = self.window_id;
 892        if let Some(focused_view_id) = self.window.focused_view_id {
 893            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 894                if let Some(mut view) = self.views.remove(&(window_id, view_id)) {
 895                    let handled = view.modifiers_changed(event, self, view_id);
 896                    self.views.insert((window_id, view_id), view);
 897                    if handled {
 898                        return true;
 899                    }
 900                } else {
 901                    log::error!("view {} does not exist", view_id)
 902                }
 903            }
 904        }
 905
 906        false
 907    }
 908
 909    pub fn invalidate(&mut self, invalidation: &mut WindowInvalidation, appearance: Appearance) {
 910        self.start_frame();
 911        self.window.appearance = appearance;
 912        for view_id in &invalidation.removed {
 913            invalidation.updated.remove(view_id);
 914            self.window.rendered_views.remove(view_id);
 915        }
 916        for view_id in &invalidation.updated {
 917            let titlebar_height = self.window.titlebar_height;
 918            let hovered_region_ids = self.window.hovered_region_ids.clone();
 919            let clicked_region_ids = self
 920                .window
 921                .clicked_button
 922                .map(|button| (self.window.clicked_region_ids.clone(), button));
 923
 924            let element = self
 925                .render_view(RenderParams {
 926                    view_id: *view_id,
 927                    titlebar_height,
 928                    hovered_region_ids,
 929                    clicked_region_ids,
 930                    refreshing: false,
 931                    appearance,
 932                })
 933                .unwrap();
 934            self.window.rendered_views.insert(*view_id, element);
 935        }
 936    }
 937
 938    pub fn render_view(&mut self, params: RenderParams) -> Result<Box<dyn AnyRootElement>> {
 939        let window_id = self.window_id;
 940        let view_id = params.view_id;
 941        let mut view = self
 942            .views
 943            .remove(&(window_id, view_id))
 944            .ok_or_else(|| anyhow!("view not found"))?;
 945        let element = view.render(self, view_id);
 946        self.views.insert((window_id, view_id), view);
 947        Ok(element)
 948    }
 949
 950    pub fn build_scene(&mut self) -> Result<Scene> {
 951        let window_size = self.window.platform_window.content_size();
 952        let scale_factor = self.window.platform_window.scale_factor();
 953
 954        let root_view_id = self.window.root_view().id();
 955        let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
 956        rendered_root.layout(SizeConstraint::strict(window_size), self)?;
 957
 958        let mut scene_builder = SceneBuilder::new(scale_factor);
 959        rendered_root.paint(
 960            &mut scene_builder,
 961            Vector2F::zero(),
 962            RectF::from_points(Vector2F::zero(), window_size),
 963            self,
 964        )?;
 965        self.window
 966            .rendered_views
 967            .insert(root_view_id, rendered_root);
 968
 969        self.window.text_layout_cache.finish_frame();
 970        let scene = scene_builder.build();
 971        self.window.cursor_regions = scene.cursor_regions();
 972        self.window.mouse_regions = scene.mouse_regions();
 973
 974        if self.window_is_active() {
 975            if let Some(event) = self.window.last_mouse_moved_event.clone() {
 976                self.dispatch_event(event, true);
 977            }
 978        }
 979
 980        Ok(scene)
 981    }
 982
 983    pub fn rect_for_text_range(&self, range_utf16: Range<usize>) -> Option<RectF> {
 984        let root_view_id = self.window.root_view().id();
 985        self.window
 986            .rendered_views
 987            .get(&root_view_id)?
 988            .rect_for_text_range(range_utf16, self)
 989            .log_err()
 990            .flatten()
 991    }
 992
 993    pub fn debug_elements(&self) -> Option<json::Value> {
 994        let view = self.window.root_view();
 995        Some(json!({
 996            "root_view": view.debug_json(self),
 997            "root_element": self.window.rendered_views.get(&view.id())
 998                .and_then(|root_element| {
 999                    root_element.debug(self).log_err()
1000                })
1001        }))
1002    }
1003
1004    pub fn set_window_title(&mut self, title: &str) {
1005        self.window.platform_window.set_title(title);
1006    }
1007
1008    pub fn set_window_edited(&mut self, edited: bool) {
1009        self.window.platform_window.set_edited(edited);
1010    }
1011
1012    pub fn is_topmost_window_for_position(&self, position: Vector2F) -> bool {
1013        self.window
1014            .platform_window
1015            .is_topmost_for_position(position)
1016    }
1017
1018    pub fn activate_window(&self) {
1019        self.window.platform_window.activate();
1020    }
1021
1022    pub fn window_is_active(&self) -> bool {
1023        self.window.is_active
1024    }
1025
1026    pub fn window_is_fullscreen(&self) -> bool {
1027        self.window.is_fullscreen
1028    }
1029
1030    pub(crate) fn handle_dispatch_action_from_effect(
1031        &mut self,
1032        view_id: Option<usize>,
1033        action: &dyn Action,
1034    ) -> 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(ParentId::View(parent_id)) =
1081                    self.parents.get(&(self.window_id, view_id))
1082                {
1083                    view_id = *parent_id;
1084                    Some(view_id)
1085                } else {
1086                    None
1087                }
1088            }))
1089    }
1090
1091    /// Returns the id of the parent of the given view, or none if the given
1092    /// view is the root.
1093    pub(crate) fn parent(&self, view_id: usize) -> Option<usize> {
1094        if let Some(ParentId::View(view_id)) = self.parents.get(&(self.window_id, view_id)) {
1095            Some(*view_id)
1096        } else {
1097            None
1098        }
1099    }
1100
1101    // Traverses the parent tree. Walks down the tree toward the passed
1102    // view calling visit with true. Then walks back up the tree calling visit with false.
1103    // If `visit` returns false this function will immediately return.
1104    fn visit_dispatch_path(
1105        &mut self,
1106        view_id: usize,
1107        mut visit: impl FnMut(usize, bool, &mut WindowContext) -> bool,
1108    ) {
1109        // List of view ids from the leaf to the root of the window
1110        let path = self.ancestors(view_id).collect::<Vec<_>>();
1111
1112        // Walk down from the root to the leaf calling visit with capture_phase = true
1113        for view_id in path.iter().rev() {
1114            if !visit(*view_id, true, self) {
1115                return;
1116            }
1117        }
1118
1119        // Walk up from the leaf to the root calling visit with capture_phase = false
1120        for view_id in path.iter() {
1121            if !visit(*view_id, false, self) {
1122                return;
1123            }
1124        }
1125    }
1126
1127    pub fn focused_view_id(&self) -> Option<usize> {
1128        self.window.focused_view_id
1129    }
1130
1131    pub fn is_child_focused(&self, view: &AnyViewHandle) -> bool {
1132        if let Some(focused_view_id) = self.focused_view_id() {
1133            self.ancestors(focused_view_id)
1134                .skip(1) // Skip self id
1135                .any(|parent| parent == view.view_id)
1136        } else {
1137            false
1138        }
1139    }
1140
1141    pub fn window_bounds(&self) -> WindowBounds {
1142        self.window.platform_window.bounds()
1143    }
1144
1145    pub fn window_appearance(&self) -> Appearance {
1146        self.window.appearance
1147    }
1148
1149    pub fn window_display_uuid(&self) -> Option<Uuid> {
1150        self.window.platform_window.screen().display_uuid()
1151    }
1152
1153    pub fn show_character_palette(&self) {
1154        self.window.platform_window.show_character_palette();
1155    }
1156
1157    pub fn minimize_window(&self) {
1158        self.window.platform_window.minimize();
1159    }
1160
1161    pub fn zoom_window(&self) {
1162        self.window.platform_window.zoom();
1163    }
1164
1165    pub fn toggle_full_screen(&self) {
1166        self.window.platform_window.toggle_full_screen();
1167    }
1168
1169    pub fn prompt(
1170        &self,
1171        level: PromptLevel,
1172        msg: &str,
1173        answers: &[&str],
1174    ) -> oneshot::Receiver<usize> {
1175        self.window.platform_window.prompt(level, msg, answers)
1176    }
1177
1178    pub fn replace_root_view<V, F>(&mut self, build_root_view: F) -> ViewHandle<V>
1179    where
1180        V: View,
1181        F: FnOnce(&mut ViewContext<V>) -> V,
1182    {
1183        let root_view = self
1184            .build_and_insert_view(ParentId::Root, |cx| Some(build_root_view(cx)))
1185            .unwrap();
1186        self.window.root_view = Some(root_view.clone().into_any());
1187        self.window.focused_view_id = Some(root_view.id());
1188        root_view
1189    }
1190
1191    pub(crate) fn build_and_insert_view<T, F>(
1192        &mut self,
1193        parent_id: ParentId,
1194        build_view: F,
1195    ) -> Option<ViewHandle<T>>
1196    where
1197        T: View,
1198        F: FnOnce(&mut ViewContext<T>) -> Option<T>,
1199    {
1200        let window_id = self.window_id;
1201        let view_id = post_inc(&mut self.next_entity_id);
1202        // Make sure we can tell child views about their parentu
1203        self.parents.insert((window_id, view_id), parent_id);
1204        let mut cx = ViewContext::mutable(self, view_id);
1205        let handle = if let Some(view) = build_view(&mut cx) {
1206            self.views.insert((window_id, view_id), Box::new(view));
1207            self.window
1208                .invalidation
1209                .get_or_insert_with(Default::default)
1210                .updated
1211                .insert(view_id);
1212            Some(ViewHandle::new(window_id, view_id, &self.ref_counts))
1213        } else {
1214            self.parents.remove(&(window_id, view_id));
1215            None
1216        };
1217        handle
1218    }
1219}
1220
1221pub struct RenderParams {
1222    pub view_id: usize,
1223    pub titlebar_height: f32,
1224    pub hovered_region_ids: HashSet<MouseRegionId>,
1225    pub clicked_region_ids: Option<(HashSet<MouseRegionId>, MouseButton)>,
1226    pub refreshing: bool,
1227    pub appearance: Appearance,
1228}
1229
1230#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
1231pub enum Axis {
1232    #[default]
1233    Horizontal,
1234    Vertical,
1235}
1236
1237impl Axis {
1238    pub fn invert(self) -> Self {
1239        match self {
1240            Self::Horizontal => Self::Vertical,
1241            Self::Vertical => Self::Horizontal,
1242        }
1243    }
1244
1245    pub fn component(&self, point: Vector2F) -> f32 {
1246        match self {
1247            Self::Horizontal => point.x(),
1248            Self::Vertical => point.y(),
1249        }
1250    }
1251}
1252
1253impl ToJson for Axis {
1254    fn to_json(&self) -> serde_json::Value {
1255        match self {
1256            Axis::Horizontal => json!("horizontal"),
1257            Axis::Vertical => json!("vertical"),
1258        }
1259    }
1260}
1261
1262impl StaticColumnCount for Axis {}
1263impl Bind for Axis {
1264    fn bind(&self, statement: &Statement, start_index: i32) -> anyhow::Result<i32> {
1265        match self {
1266            Axis::Horizontal => "Horizontal",
1267            Axis::Vertical => "Vertical",
1268        }
1269        .bind(statement, start_index)
1270    }
1271}
1272
1273impl Column for Axis {
1274    fn column(statement: &mut Statement, start_index: i32) -> anyhow::Result<(Self, i32)> {
1275        String::column(statement, start_index).and_then(|(axis_text, next_index)| {
1276            Ok((
1277                match axis_text.as_str() {
1278                    "Horizontal" => Axis::Horizontal,
1279                    "Vertical" => Axis::Vertical,
1280                    _ => bail!("Stored serialized item kind is incorrect"),
1281                },
1282                next_index,
1283            ))
1284        })
1285    }
1286}
1287
1288pub trait Vector2FExt {
1289    fn along(self, axis: Axis) -> f32;
1290}
1291
1292impl Vector2FExt for Vector2F {
1293    fn along(self, axis: Axis) -> f32 {
1294        match axis {
1295            Axis::Horizontal => self.x(),
1296            Axis::Vertical => self.y(),
1297        }
1298    }
1299}
1300
1301#[derive(Copy, Clone, Debug)]
1302pub struct SizeConstraint {
1303    pub min: Vector2F,
1304    pub max: Vector2F,
1305}
1306
1307impl SizeConstraint {
1308    pub fn new(min: Vector2F, max: Vector2F) -> Self {
1309        Self { min, max }
1310    }
1311
1312    pub fn strict(size: Vector2F) -> Self {
1313        Self {
1314            min: size,
1315            max: size,
1316        }
1317    }
1318
1319    pub fn strict_along(axis: Axis, max: f32) -> Self {
1320        match axis {
1321            Axis::Horizontal => Self {
1322                min: vec2f(max, 0.0),
1323                max: vec2f(max, f32::INFINITY),
1324            },
1325            Axis::Vertical => Self {
1326                min: vec2f(0.0, max),
1327                max: vec2f(f32::INFINITY, max),
1328            },
1329        }
1330    }
1331
1332    pub fn max_along(&self, axis: Axis) -> f32 {
1333        match axis {
1334            Axis::Horizontal => self.max.x(),
1335            Axis::Vertical => self.max.y(),
1336        }
1337    }
1338
1339    pub fn min_along(&self, axis: Axis) -> f32 {
1340        match axis {
1341            Axis::Horizontal => self.min.x(),
1342            Axis::Vertical => self.min.y(),
1343        }
1344    }
1345
1346    pub fn constrain(&self, size: Vector2F) -> Vector2F {
1347        vec2f(
1348            size.x().min(self.max.x()).max(self.min.x()),
1349            size.y().min(self.max.y()).max(self.min.y()),
1350        )
1351    }
1352}
1353
1354impl Default for SizeConstraint {
1355    fn default() -> Self {
1356        SizeConstraint {
1357            min: Vector2F::zero(),
1358            max: Vector2F::splat(f32::INFINITY),
1359        }
1360    }
1361}
1362
1363impl ToJson for SizeConstraint {
1364    fn to_json(&self) -> serde_json::Value {
1365        json!({
1366            "min": self.min.to_json(),
1367            "max": self.max.to_json(),
1368        })
1369    }
1370}
1371
1372pub struct ChildView {
1373    view_id: usize,
1374    view_name: &'static str,
1375}
1376
1377impl ChildView {
1378    pub fn new(view: &AnyViewHandle, cx: &AppContext) -> Self {
1379        let view_name = cx.view_ui_name(view.window_id(), view.id()).unwrap();
1380        Self {
1381            view_id: view.id(),
1382            view_name,
1383        }
1384    }
1385}
1386
1387impl<V: View> Drawable<V> for ChildView {
1388    type LayoutState = ();
1389    type PaintState = ();
1390
1391    fn layout(
1392        &mut self,
1393        constraint: SizeConstraint,
1394        _: &mut V,
1395        cx: &mut ViewContext<V>,
1396    ) -> (Vector2F, Self::LayoutState) {
1397        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1398            let size = rendered_view
1399                .layout(constraint, cx)
1400                .log_err()
1401                .unwrap_or(Vector2F::zero());
1402            cx.window.rendered_views.insert(self.view_id, rendered_view);
1403            (size, ())
1404        } else {
1405            log::error!(
1406                "layout called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1407                self.view_id,
1408                self.view_name
1409            );
1410            (Vector2F::zero(), ())
1411        }
1412    }
1413
1414    fn paint(
1415        &mut self,
1416        scene: &mut SceneBuilder,
1417        bounds: RectF,
1418        visible_bounds: RectF,
1419        _: &mut Self::LayoutState,
1420        _: &mut V,
1421        cx: &mut ViewContext<V>,
1422    ) {
1423        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1424            rendered_view
1425                .paint(scene, bounds.origin(), visible_bounds, cx)
1426                .log_err();
1427            cx.window.rendered_views.insert(self.view_id, rendered_view);
1428        } else {
1429            log::error!(
1430                "paint called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1431                self.view_id,
1432                self.view_name
1433            );
1434        }
1435    }
1436
1437    fn rect_for_text_range(
1438        &self,
1439        range_utf16: Range<usize>,
1440        _: RectF,
1441        _: RectF,
1442        _: &Self::LayoutState,
1443        _: &Self::PaintState,
1444        _: &V,
1445        cx: &ViewContext<V>,
1446    ) -> Option<RectF> {
1447        if let Some(rendered_view) = cx.window.rendered_views.get(&self.view_id) {
1448            rendered_view
1449                .rect_for_text_range(range_utf16, &cx.window_context)
1450                .log_err()
1451                .flatten()
1452        } else {
1453            log::error!(
1454                "rect_for_text_range called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1455                self.view_id,
1456                self.view_name
1457            );
1458            None
1459        }
1460    }
1461
1462    fn debug(
1463        &self,
1464        bounds: RectF,
1465        _: &Self::LayoutState,
1466        _: &Self::PaintState,
1467        _: &V,
1468        cx: &ViewContext<V>,
1469    ) -> serde_json::Value {
1470        json!({
1471            "type": "ChildView",
1472            "view_id": self.view_id,
1473            "bounds": bounds.to_json(),
1474            "view": if let Some(view) = cx.views.get(&(cx.window_id, self.view_id))  {
1475                view.debug_json(cx)
1476            } else {
1477                json!(null)
1478            },
1479            "child": if let Some(element) = cx.window.rendered_views.get(&self.view_id) {
1480                element.debug(&cx.window_context).log_err().unwrap_or_else(|| json!(null))
1481            } else {
1482                json!(null)
1483            }
1484        })
1485    }
1486}