window.rs

   1use crate::{
   2    elements::AnyRootElement,
   3    geometry::{rect::RectF, Size},
   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, EventHandler, MouseClick, MouseClickOut, MouseDown, MouseDownOut, MouseDrag,
  12        MouseEvent, MouseHover, MouseMove, MouseMoveOut, MouseScrollWheel, MouseUp, MouseUpOut,
  13        Scene,
  14    },
  15    text_layout::TextLayoutCache,
  16    util::post_inc,
  17    Action, AnyView, AnyViewHandle, AnyWindowHandle, AppContext, BorrowAppContext,
  18    BorrowWindowContext, Effect, Element, Entity, Handle, LayoutContext, MouseRegion,
  19    MouseRegionId, PaintContext, SceneBuilder, Subscription, View, ViewContext, ViewHandle,
  20    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    mem,
  35    ops::{Deref, DerefMut, Range, Sub},
  36};
  37use taffy::{
  38    tree::{Measurable, MeasureFunc},
  39    Taffy,
  40};
  41use util::ResultExt;
  42use uuid::Uuid;
  43
  44use super::{Reference, ViewMetadata};
  45
  46pub struct Window {
  47    layout_engines: Vec<LayoutEngine>,
  48    pub(crate) root_view: Option<AnyViewHandle>,
  49    pub(crate) focused_view_id: Option<usize>,
  50    pub(crate) parents: HashMap<usize, usize>,
  51    pub(crate) is_active: bool,
  52    pub(crate) is_fullscreen: bool,
  53    pub(crate) invalidation: Option<WindowInvalidation>,
  54    pub(crate) platform_window: Box<dyn platform::Window>,
  55    pub(crate) rendered_views: HashMap<usize, Box<dyn AnyRootElement>>,
  56    titlebar_height: f32,
  57    appearance: Appearance,
  58    cursor_regions: Vec<CursorRegion>,
  59    mouse_regions: Vec<(MouseRegion, usize)>,
  60    event_handlers: Vec<EventHandler>,
  61    last_mouse_moved_event: Option<Event>,
  62    last_mouse_position: Vector2F,
  63    pub(crate) hovered_region_ids: Vec<MouseRegionId>,
  64    pub(crate) clicked_region_ids: Vec<MouseRegionId>,
  65    pub(crate) clicked_region: Option<(MouseRegionId, MouseButton)>,
  66    text_layout_cache: TextLayoutCache,
  67}
  68
  69impl Window {
  70    pub fn new<V, F>(
  71        handle: AnyWindowHandle,
  72        platform_window: Box<dyn platform::Window>,
  73        cx: &mut AppContext,
  74        build_view: F,
  75    ) -> Self
  76    where
  77        V: View,
  78        F: FnOnce(&mut ViewContext<V>) -> V,
  79    {
  80        let titlebar_height = platform_window.titlebar_height();
  81        let appearance = platform_window.appearance();
  82        let mut window = Self {
  83            layout_engines: Vec::new(),
  84            root_view: None,
  85            focused_view_id: None,
  86            parents: Default::default(),
  87            is_active: false,
  88            invalidation: None,
  89            is_fullscreen: false,
  90            platform_window,
  91            rendered_views: Default::default(),
  92            cursor_regions: Default::default(),
  93            mouse_regions: Default::default(),
  94            event_handlers: Default::default(),
  95            text_layout_cache: TextLayoutCache::new(cx.font_system.clone()),
  96            last_mouse_moved_event: None,
  97            last_mouse_position: Vector2F::zero(),
  98            hovered_region_ids: Default::default(),
  99            clicked_region_ids: Default::default(),
 100            clicked_region: None,
 101            titlebar_height,
 102            appearance,
 103        };
 104
 105        let mut window_context = WindowContext::mutable(cx, &mut window, handle);
 106        let root_view = window_context.add_view(|cx| build_view(cx));
 107        if let Some(invalidation) = window_context.window.invalidation.take() {
 108            window_context.invalidate(invalidation, appearance);
 109        }
 110        window.focused_view_id = Some(root_view.id());
 111        window.root_view = Some(root_view.into_any());
 112        window
 113    }
 114
 115    pub fn root_view(&self) -> &AnyViewHandle {
 116        &self
 117            .root_view
 118            .as_ref()
 119            .expect("root_view called during window construction")
 120    }
 121
 122    pub fn take_event_handlers(&mut self) -> Vec<EventHandler> {
 123        mem::take(&mut self.event_handlers)
 124    }
 125}
 126
 127pub struct WindowContext<'a> {
 128    pub(crate) app_context: Reference<'a, AppContext>,
 129    pub(crate) window: Reference<'a, Window>,
 130    pub(crate) window_handle: AnyWindowHandle,
 131    pub(crate) removed: bool,
 132}
 133
 134impl Deref for WindowContext<'_> {
 135    type Target = AppContext;
 136
 137    fn deref(&self) -> &Self::Target {
 138        &self.app_context
 139    }
 140}
 141
 142impl DerefMut for WindowContext<'_> {
 143    fn deref_mut(&mut self) -> &mut Self::Target {
 144        &mut self.app_context
 145    }
 146}
 147
 148impl BorrowAppContext for WindowContext<'_> {
 149    fn read_with<T, F: FnOnce(&AppContext) -> T>(&self, f: F) -> T {
 150        self.app_context.read_with(f)
 151    }
 152
 153    fn update<T, F: FnOnce(&mut AppContext) -> T>(&mut self, f: F) -> T {
 154        self.app_context.update(f)
 155    }
 156}
 157
 158impl BorrowWindowContext for WindowContext<'_> {
 159    type Result<T> = T;
 160
 161    fn read_window<T, F: FnOnce(&WindowContext) -> T>(&self, handle: AnyWindowHandle, f: F) -> T {
 162        if self.window_handle == handle {
 163            f(self)
 164        } else {
 165            panic!("read_with called with id of window that does not belong to this context")
 166        }
 167    }
 168
 169    fn read_window_optional<T, F>(&self, window: AnyWindowHandle, f: F) -> Option<T>
 170    where
 171        F: FnOnce(&WindowContext) -> Option<T>,
 172    {
 173        BorrowWindowContext::read_window(self, window, f)
 174    }
 175
 176    fn update_window<T, F: FnOnce(&mut WindowContext) -> T>(
 177        &mut self,
 178        handle: AnyWindowHandle,
 179        f: F,
 180    ) -> T {
 181        if self.window_handle == handle {
 182            f(self)
 183        } else {
 184            panic!("update called with id of window that does not belong to this context")
 185        }
 186    }
 187
 188    fn update_window_optional<T, F>(&mut self, handle: AnyWindowHandle, f: F) -> Option<T>
 189    where
 190        F: FnOnce(&mut WindowContext) -> Option<T>,
 191    {
 192        BorrowWindowContext::update_window(self, handle, f)
 193    }
 194}
 195
 196impl<'a> WindowContext<'a> {
 197    pub fn mutable(
 198        app_context: &'a mut AppContext,
 199        window: &'a mut Window,
 200        handle: AnyWindowHandle,
 201    ) -> Self {
 202        Self {
 203            app_context: Reference::Mutable(app_context),
 204            window: Reference::Mutable(window),
 205            window_handle: handle,
 206            removed: false,
 207        }
 208    }
 209
 210    pub fn immutable(
 211        app_context: &'a AppContext,
 212        window: &'a Window,
 213        handle: AnyWindowHandle,
 214    ) -> Self {
 215        Self {
 216            app_context: Reference::Immutable(app_context),
 217            window: Reference::Immutable(window),
 218            window_handle: handle,
 219            removed: false,
 220        }
 221    }
 222
 223    pub fn repaint(&mut self) {
 224        let window = self.window();
 225        self.pending_effects
 226            .push_back(Effect::RepaintWindow { window });
 227    }
 228
 229    pub fn layout_engine(&mut self) -> Option<&mut LayoutEngine> {
 230        self.window.layout_engines.last_mut()
 231    }
 232
 233    pub fn push_layout_engine(&mut self, engine: LayoutEngine) {
 234        self.window.layout_engines.push(engine);
 235    }
 236
 237    pub fn pop_layout_engine(&mut self) -> Option<LayoutEngine> {
 238        self.window.layout_engines.pop()
 239    }
 240
 241    pub fn remove_window(&mut self) {
 242        self.removed = true;
 243    }
 244
 245    pub fn window(&self) -> AnyWindowHandle {
 246        self.window_handle
 247    }
 248
 249    pub fn app_context(&mut self) -> &mut AppContext {
 250        &mut self.app_context
 251    }
 252
 253    pub fn root_view(&self) -> &AnyViewHandle {
 254        self.window.root_view()
 255    }
 256
 257    pub fn window_size(&self) -> Vector2F {
 258        self.window.platform_window.content_size()
 259    }
 260
 261    pub fn mouse_position(&self) -> Vector2F {
 262        self.window.platform_window.mouse_position()
 263    }
 264
 265    pub fn text_layout_cache(&self) -> &TextLayoutCache {
 266        &self.window.text_layout_cache
 267    }
 268
 269    pub(crate) fn update_any_view<F, T>(&mut self, view_id: usize, f: F) -> Option<T>
 270    where
 271        F: FnOnce(&mut dyn AnyView, &mut Self) -> T,
 272    {
 273        let handle = self.window_handle;
 274        let mut view = self.views.remove(&(handle, view_id))?;
 275        let result = f(view.as_mut(), self);
 276        self.views.insert((handle, view_id), view);
 277        Some(result)
 278    }
 279
 280    pub(crate) fn update_view<V: 'static, S>(
 281        &mut self,
 282        handle: &ViewHandle<V>,
 283        update: &mut dyn FnMut(&mut V, &mut ViewContext<V>) -> S,
 284    ) -> S {
 285        self.update_any_view(handle.view_id, |view, cx| {
 286            let mut cx = ViewContext::mutable(cx, handle.view_id);
 287            update(
 288                view.as_any_mut()
 289                    .downcast_mut()
 290                    .expect("downcast is type safe"),
 291                &mut cx,
 292            )
 293        })
 294        .expect("view is already on the stack")
 295    }
 296
 297    pub fn defer(&mut self, callback: impl 'static + FnOnce(&mut WindowContext)) {
 298        let handle = self.window_handle;
 299        self.app_context.defer(move |cx| {
 300            cx.update_window(handle, |cx| callback(cx));
 301        })
 302    }
 303
 304    pub fn update_global<T, F, U>(&mut self, update: F) -> U
 305    where
 306        T: 'static,
 307        F: FnOnce(&mut T, &mut Self) -> U,
 308    {
 309        AppContext::update_global_internal(self, |global, cx| update(global, cx))
 310    }
 311
 312    pub fn update_default_global<T, F, U>(&mut self, update: F) -> U
 313    where
 314        T: 'static + Default,
 315        F: FnOnce(&mut T, &mut Self) -> U,
 316    {
 317        AppContext::update_default_global_internal(self, |global, cx| update(global, cx))
 318    }
 319
 320    pub fn subscribe<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
 321    where
 322        E: Entity,
 323        E::Event: 'static,
 324        H: Handle<E>,
 325        F: 'static + FnMut(H, &E::Event, &mut WindowContext),
 326    {
 327        self.subscribe_internal(handle, move |emitter, event, cx| {
 328            callback(emitter, event, cx);
 329            true
 330        })
 331    }
 332
 333    pub fn subscribe_internal<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
 334    where
 335        E: Entity,
 336        E::Event: 'static,
 337        H: Handle<E>,
 338        F: 'static + FnMut(H, &E::Event, &mut WindowContext) -> bool,
 339    {
 340        let window_handle = self.window_handle;
 341        self.app_context
 342            .subscribe_internal(handle, move |emitter, event, cx| {
 343                cx.update_window(window_handle, |cx| callback(emitter, event, cx))
 344                    .unwrap_or(false)
 345            })
 346    }
 347
 348    pub(crate) fn observe_window_activation<F>(&mut self, callback: F) -> Subscription
 349    where
 350        F: 'static + FnMut(bool, &mut WindowContext) -> bool,
 351    {
 352        let handle = self.window_handle;
 353        let subscription_id = post_inc(&mut self.next_subscription_id);
 354        self.pending_effects
 355            .push_back(Effect::WindowActivationObservation {
 356                window: handle,
 357                subscription_id,
 358                callback: Box::new(callback),
 359            });
 360        Subscription::WindowActivationObservation(
 361            self.window_activation_observations
 362                .subscribe(handle, subscription_id),
 363        )
 364    }
 365
 366    pub(crate) fn observe_fullscreen<F>(&mut self, callback: F) -> Subscription
 367    where
 368        F: 'static + FnMut(bool, &mut WindowContext) -> bool,
 369    {
 370        let window = self.window_handle;
 371        let subscription_id = post_inc(&mut self.next_subscription_id);
 372        self.pending_effects
 373            .push_back(Effect::WindowFullscreenObservation {
 374                window,
 375                subscription_id,
 376                callback: Box::new(callback),
 377            });
 378        Subscription::WindowActivationObservation(
 379            self.window_activation_observations
 380                .subscribe(window, subscription_id),
 381        )
 382    }
 383
 384    pub(crate) fn observe_window_bounds<F>(&mut self, callback: F) -> Subscription
 385    where
 386        F: 'static + FnMut(WindowBounds, Uuid, &mut WindowContext) -> bool,
 387    {
 388        let window = self.window_handle;
 389        let subscription_id = post_inc(&mut self.next_subscription_id);
 390        self.pending_effects
 391            .push_back(Effect::WindowBoundsObservation {
 392                window,
 393                subscription_id,
 394                callback: Box::new(callback),
 395            });
 396        Subscription::WindowBoundsObservation(
 397            self.window_bounds_observations
 398                .subscribe(window, subscription_id),
 399        )
 400    }
 401
 402    pub fn observe_keystrokes<F>(&mut self, callback: F) -> Subscription
 403    where
 404        F: 'static
 405            + FnMut(&Keystroke, &MatchResult, Option<&Box<dyn Action>>, &mut WindowContext) -> bool,
 406    {
 407        let window = self.window_handle;
 408        let subscription_id = post_inc(&mut self.next_subscription_id);
 409        self.keystroke_observations
 410            .add_callback(window, subscription_id, Box::new(callback));
 411        Subscription::KeystrokeObservation(
 412            self.keystroke_observations
 413                .subscribe(window, subscription_id),
 414        )
 415    }
 416
 417    pub(crate) fn available_actions(
 418        &self,
 419        view_id: usize,
 420    ) -> Vec<(&'static str, Box<dyn Action>, SmallVec<[Binding; 1]>)> {
 421        let handle = self.window_handle;
 422        let mut contexts = Vec::new();
 423        let mut handler_depths_by_action_id = HashMap::<TypeId, usize>::default();
 424        for (depth, view_id) in self.ancestors(view_id).enumerate() {
 425            if let Some(view_metadata) = self.views_metadata.get(&(handle, view_id)) {
 426                contexts.push(view_metadata.keymap_context.clone());
 427                if let Some(actions) = self.actions.get(&view_metadata.type_id) {
 428                    handler_depths_by_action_id
 429                        .extend(actions.keys().copied().map(|action_id| (action_id, depth)));
 430                }
 431            } else {
 432                log::error!(
 433                    "view {} not found when computing available actions",
 434                    view_id
 435                );
 436            }
 437        }
 438
 439        handler_depths_by_action_id.extend(
 440            self.global_actions
 441                .keys()
 442                .copied()
 443                .map(|action_id| (action_id, contexts.len())),
 444        );
 445
 446        self.action_deserializers
 447            .iter()
 448            .filter_map(move |(name, (action_id, deserialize))| {
 449                if let Some(action_depth) = handler_depths_by_action_id.get(action_id).copied() {
 450                    let action = deserialize(serde_json::Value::Object(Default::default())).ok()?;
 451                    let bindings = self
 452                        .keystroke_matcher
 453                        .bindings_for_action(*action_id)
 454                        .filter(|b| {
 455                            action.eq(b.action())
 456                                && (0..=action_depth)
 457                                    .any(|depth| b.match_context(&contexts[depth..]))
 458                        })
 459                        .cloned()
 460                        .collect();
 461                    Some((*name, action, bindings))
 462                } else {
 463                    None
 464                }
 465            })
 466            .collect()
 467    }
 468
 469    pub(crate) fn dispatch_keystroke(&mut self, keystroke: &Keystroke) -> bool {
 470        let handle = self.window_handle;
 471        if let Some(focused_view_id) = self.focused_view_id() {
 472            let dispatch_path = self
 473                .ancestors(focused_view_id)
 474                .filter_map(|view_id| {
 475                    self.views_metadata
 476                        .get(&(handle, view_id))
 477                        .map(|view| (view_id, view.keymap_context.clone()))
 478                })
 479                .collect();
 480
 481            let match_result = self
 482                .keystroke_matcher
 483                .push_keystroke(keystroke.clone(), dispatch_path);
 484            let mut handled_by = None;
 485
 486            let keystroke_handled = match &match_result {
 487                MatchResult::None => false,
 488                MatchResult::Pending => true,
 489                MatchResult::Matches(matches) => {
 490                    for (view_id, action) in matches {
 491                        if self.dispatch_action(Some(*view_id), action.as_ref()) {
 492                            self.keystroke_matcher.clear_pending();
 493                            handled_by = Some(action.boxed_clone());
 494                            break;
 495                        }
 496                    }
 497                    handled_by.is_some()
 498                }
 499            };
 500
 501            self.keystroke(handle, keystroke.clone(), handled_by, match_result.clone());
 502            keystroke_handled
 503        } else {
 504            self.keystroke(handle, keystroke.clone(), None, MatchResult::None);
 505            false
 506        }
 507    }
 508
 509    pub(crate) fn dispatch_event(&mut self, event: Event, event_reused: bool) -> bool {
 510        if !event_reused {
 511            self.dispatch_to_new_event_handlers(&event);
 512        }
 513
 514        let mut mouse_events = SmallVec::<[_; 2]>::new();
 515        let mut notified_views: HashSet<usize> = Default::default();
 516        let handle = self.window_handle;
 517
 518        // 1. Handle platform event. Keyboard events get dispatched immediately, while mouse events
 519        //    get mapped into the mouse-specific MouseEvent type.
 520        //  -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
 521        //  -> Also updates mouse-related state
 522        match &event {
 523            Event::KeyDown(e) => return self.dispatch_key_down(e),
 524
 525            Event::KeyUp(e) => return self.dispatch_key_up(e),
 526
 527            Event::ModifiersChanged(e) => return self.dispatch_modifiers_changed(e),
 528
 529            Event::MouseDown(e) => {
 530                // Click events are weird because they can be fired after a drag event.
 531                // MDN says that browsers handle this by starting from 'the most
 532                // specific ancestor element that contained both [positions]'
 533                // So we need to store the overlapping regions on mouse down.
 534
 535                // If there is already region being clicked, don't replace it.
 536                if self.window.clicked_region.is_none() {
 537                    self.window.clicked_region_ids = self
 538                        .window
 539                        .mouse_regions
 540                        .iter()
 541                        .filter_map(|(region, _)| {
 542                            if region.bounds.contains_point(e.position) {
 543                                Some(region.id())
 544                            } else {
 545                                None
 546                            }
 547                        })
 548                        .collect();
 549
 550                    let mut highest_z_index = 0;
 551                    let mut clicked_region_id = None;
 552                    for (region, z_index) in self.window.mouse_regions.iter() {
 553                        if region.bounds.contains_point(e.position) && *z_index >= highest_z_index {
 554                            highest_z_index = *z_index;
 555                            clicked_region_id = Some(region.id());
 556                        }
 557                    }
 558
 559                    self.window.clicked_region =
 560                        clicked_region_id.map(|region_id| (region_id, e.button));
 561                }
 562
 563                mouse_events.push(MouseEvent::Down(MouseDown {
 564                    region: Default::default(),
 565                    platform_event: e.clone(),
 566                }));
 567                mouse_events.push(MouseEvent::DownOut(MouseDownOut {
 568                    region: Default::default(),
 569                    platform_event: e.clone(),
 570                }));
 571            }
 572
 573            Event::MouseUp(e) => {
 574                // NOTE: The order of event pushes is important! MouseUp events MUST be fired
 575                // before click events, and so the MouseUp events need to be pushed before
 576                // MouseClick events.
 577
 578                // Synthesize one last drag event to end the drag
 579                mouse_events.push(MouseEvent::Drag(MouseDrag {
 580                    region: Default::default(),
 581                    prev_mouse_position: self.window.last_mouse_position,
 582                    platform_event: MouseMovedEvent {
 583                        position: e.position,
 584                        pressed_button: Some(e.button),
 585                        modifiers: e.modifiers,
 586                    },
 587                    end: true,
 588                }));
 589                mouse_events.push(MouseEvent::Up(MouseUp {
 590                    region: Default::default(),
 591                    platform_event: e.clone(),
 592                }));
 593                mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 594                    region: Default::default(),
 595                    platform_event: e.clone(),
 596                }));
 597                mouse_events.push(MouseEvent::Click(MouseClick {
 598                    region: Default::default(),
 599                    platform_event: e.clone(),
 600                }));
 601                mouse_events.push(MouseEvent::ClickOut(MouseClickOut {
 602                    region: Default::default(),
 603                    platform_event: e.clone(),
 604                }));
 605            }
 606
 607            Event::MouseMoved(
 608                e @ MouseMovedEvent {
 609                    position,
 610                    pressed_button,
 611                    ..
 612                },
 613            ) => {
 614                let mut style_to_assign = CursorStyle::Arrow;
 615                for region in self.window.cursor_regions.iter().rev() {
 616                    if region.bounds.contains_point(*position) {
 617                        style_to_assign = region.style;
 618                        break;
 619                    }
 620                }
 621
 622                if self
 623                    .window
 624                    .platform_window
 625                    .is_topmost_for_position(*position)
 626                {
 627                    self.platform().set_cursor_style(style_to_assign);
 628                }
 629
 630                if !event_reused {
 631                    if pressed_button.is_some() {
 632                        mouse_events.push(MouseEvent::Drag(MouseDrag {
 633                            region: Default::default(),
 634                            prev_mouse_position: self.window.last_mouse_position,
 635                            platform_event: e.clone(),
 636                            end: false,
 637                        }));
 638                    } else if let Some((_, clicked_button)) = self.window.clicked_region {
 639                        mouse_events.push(MouseEvent::Drag(MouseDrag {
 640                            region: Default::default(),
 641                            prev_mouse_position: self.window.last_mouse_position,
 642                            platform_event: e.clone(),
 643                            end: true,
 644                        }));
 645
 646                        // Mouse up event happened outside the current window. Simulate mouse up button event
 647                        let button_event = e.to_button_event(clicked_button);
 648                        mouse_events.push(MouseEvent::Up(MouseUp {
 649                            region: Default::default(),
 650                            platform_event: button_event.clone(),
 651                        }));
 652                        mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 653                            region: Default::default(),
 654                            platform_event: button_event.clone(),
 655                        }));
 656                        mouse_events.push(MouseEvent::Click(MouseClick {
 657                            region: Default::default(),
 658                            platform_event: button_event.clone(),
 659                        }));
 660                    }
 661
 662                    mouse_events.push(MouseEvent::Move(MouseMove {
 663                        region: Default::default(),
 664                        platform_event: e.clone(),
 665                    }));
 666                }
 667
 668                mouse_events.push(MouseEvent::Hover(MouseHover {
 669                    region: Default::default(),
 670                    platform_event: e.clone(),
 671                    started: false,
 672                }));
 673                mouse_events.push(MouseEvent::MoveOut(MouseMoveOut {
 674                    region: Default::default(),
 675                }));
 676
 677                self.window.last_mouse_moved_event = Some(event.clone());
 678            }
 679
 680            Event::MouseExited(event) => {
 681                // When the platform sends a MouseExited event, synthesize
 682                // a MouseMoved event whose position is outside the window's
 683                // bounds so that hover and cursor state can be updated.
 684                return self.dispatch_event(
 685                    Event::MouseMoved(MouseMovedEvent {
 686                        position: event.position,
 687                        pressed_button: event.pressed_button,
 688                        modifiers: event.modifiers,
 689                    }),
 690                    event_reused,
 691                );
 692            }
 693
 694            Event::ScrollWheel(e) => mouse_events.push(MouseEvent::ScrollWheel(MouseScrollWheel {
 695                region: Default::default(),
 696                platform_event: e.clone(),
 697            })),
 698        }
 699
 700        if let Some(position) = event.position() {
 701            self.window.last_mouse_position = position;
 702        }
 703
 704        // 2. Dispatch mouse events on regions
 705        let mut any_event_handled = false;
 706        for mut mouse_event in mouse_events {
 707            let mut valid_regions = Vec::new();
 708
 709            // GPUI elements are arranged by z_index but sibling elements can register overlapping
 710            // mouse regions. As such, hover events are only fired on overlapping elements which
 711            // are at the same z-index as the topmost element which overlaps with the mouse.
 712            match &mouse_event {
 713                MouseEvent::Hover(_) => {
 714                    let mut highest_z_index = None;
 715                    let mouse_position = self.mouse_position();
 716                    let window = &mut *self.window;
 717                    let prev_hovered_regions = mem::take(&mut window.hovered_region_ids);
 718                    for (region, z_index) in window.mouse_regions.iter().rev() {
 719                        // Allow mouse regions to appear transparent to hovers
 720                        if !region.hoverable {
 721                            continue;
 722                        }
 723
 724                        let contains_mouse = region.bounds.contains_point(mouse_position);
 725
 726                        if contains_mouse && highest_z_index.is_none() {
 727                            highest_z_index = Some(z_index);
 728                        }
 729
 730                        // This unwrap relies on short circuiting boolean expressions
 731                        // The right side of the && is only executed when contains_mouse
 732                        // is true, and we know above that when contains_mouse is true
 733                        // highest_z_index is set.
 734                        if contains_mouse && z_index == highest_z_index.unwrap() {
 735                            //Ensure that hover entrance events aren't sent twice
 736                            if let Err(ix) = window.hovered_region_ids.binary_search(&region.id()) {
 737                                window.hovered_region_ids.insert(ix, region.id());
 738                            }
 739                            // window.hovered_region_ids.insert(region.id());
 740                            if !prev_hovered_regions.contains(&region.id()) {
 741                                valid_regions.push(region.clone());
 742                                if region.notify_on_hover {
 743                                    notified_views.insert(region.id().view_id());
 744                                }
 745                            }
 746                        } else {
 747                            // Ensure that hover exit events aren't sent twice
 748                            if prev_hovered_regions.contains(&region.id()) {
 749                                valid_regions.push(region.clone());
 750                                if region.notify_on_hover {
 751                                    notified_views.insert(region.id().view_id());
 752                                }
 753                            }
 754                        }
 755                    }
 756                }
 757
 758                MouseEvent::Down(_) | MouseEvent::Up(_) => {
 759                    for (region, _) in self.window.mouse_regions.iter().rev() {
 760                        if region.bounds.contains_point(self.mouse_position()) {
 761                            valid_regions.push(region.clone());
 762                            if region.notify_on_click {
 763                                notified_views.insert(region.id().view_id());
 764                            }
 765                        }
 766                    }
 767                }
 768
 769                MouseEvent::Click(e) => {
 770                    // Only raise click events if the released button is the same as the one stored
 771                    if self
 772                        .window
 773                        .clicked_region
 774                        .map(|(_, clicked_button)| clicked_button == e.button)
 775                        .unwrap_or(false)
 776                    {
 777                        // Clear clicked regions and clicked button
 778                        let clicked_region_ids = std::mem::replace(
 779                            &mut self.window.clicked_region_ids,
 780                            Default::default(),
 781                        );
 782                        self.window.clicked_region = None;
 783
 784                        // Find regions which still overlap with the mouse since the last MouseDown happened
 785                        for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 786                            if clicked_region_ids.contains(&mouse_region.id()) {
 787                                if mouse_region.bounds.contains_point(self.mouse_position()) {
 788                                    valid_regions.push(mouse_region.clone());
 789                                }
 790                            }
 791                        }
 792                    }
 793                }
 794
 795                MouseEvent::Drag(_) => {
 796                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 797                        if self.window.clicked_region_ids.contains(&mouse_region.id()) {
 798                            valid_regions.push(mouse_region.clone());
 799                        }
 800                    }
 801                }
 802
 803                MouseEvent::MoveOut(_)
 804                | MouseEvent::UpOut(_)
 805                | MouseEvent::DownOut(_)
 806                | MouseEvent::ClickOut(_) => {
 807                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 808                        // NOT contains
 809                        if !mouse_region.bounds.contains_point(self.mouse_position()) {
 810                            valid_regions.push(mouse_region.clone());
 811                        }
 812                    }
 813                }
 814
 815                _ => {
 816                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 817                        // Contains
 818                        if mouse_region.bounds.contains_point(self.mouse_position()) {
 819                            valid_regions.push(mouse_region.clone());
 820                        }
 821                    }
 822                }
 823            }
 824
 825            //3. Fire region events
 826            let hovered_region_ids = self.window.hovered_region_ids.clone();
 827            for valid_region in valid_regions.into_iter() {
 828                let mut handled = false;
 829                mouse_event.set_region(valid_region.bounds);
 830                if let MouseEvent::Hover(e) = &mut mouse_event {
 831                    e.started = hovered_region_ids.contains(&valid_region.id())
 832                }
 833                // Handle Down events if the MouseRegion has a Click or Drag handler. This makes the api more intuitive as you would
 834                // not expect a MouseRegion to be transparent to Down events if it also has a Click handler.
 835                // This behavior can be overridden by adding a Down handler
 836                if let MouseEvent::Down(e) = &mouse_event {
 837                    let has_click = valid_region
 838                        .handlers
 839                        .contains(MouseEvent::click_disc(), Some(e.button));
 840                    let has_drag = valid_region
 841                        .handlers
 842                        .contains(MouseEvent::drag_disc(), Some(e.button));
 843                    let has_down = valid_region
 844                        .handlers
 845                        .contains(MouseEvent::down_disc(), Some(e.button));
 846                    if !has_down && (has_click || has_drag) {
 847                        handled = true;
 848                    }
 849                }
 850
 851                // `event_consumed` should only be true if there are any handlers for this event.
 852                let mut event_consumed = handled;
 853                if let Some(callbacks) = valid_region.handlers.get(&mouse_event.handler_key()) {
 854                    for callback in callbacks {
 855                        handled = true;
 856                        let view_id = valid_region.id().view_id();
 857                        self.update_any_view(view_id, |view, cx| {
 858                            handled = callback(mouse_event.clone(), view.as_any_mut(), cx, view_id);
 859                        });
 860                        event_consumed |= handled;
 861                        any_event_handled |= handled;
 862                    }
 863                }
 864
 865                any_event_handled |= handled;
 866
 867                // For bubbling events, if the event was handled, don't continue dispatching.
 868                // This only makes sense for local events which return false from is_capturable.
 869                if event_consumed && mouse_event.is_capturable() {
 870                    break;
 871                }
 872            }
 873        }
 874
 875        for view_id in notified_views {
 876            self.notify_view(handle, view_id);
 877        }
 878
 879        any_event_handled
 880    }
 881
 882    fn dispatch_to_new_event_handlers(&mut self, event: &Event) {
 883        if let Some(mouse_event) = event.mouse_event() {
 884            let event_handlers = self.window.take_event_handlers();
 885            for event_handler in event_handlers.iter().rev() {
 886                if event_handler.event_type == mouse_event.type_id() {
 887                    (event_handler.handler)(mouse_event, self);
 888                }
 889            }
 890            self.window.event_handlers = event_handlers;
 891        }
 892    }
 893
 894    pub(crate) fn dispatch_key_down(&mut self, event: &KeyDownEvent) -> bool {
 895        let handle = self.window_handle;
 896        if let Some(focused_view_id) = self.window.focused_view_id {
 897            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 898                if let Some(mut view) = self.views.remove(&(handle, view_id)) {
 899                    let handled = view.key_down(event, self, view_id);
 900                    self.views.insert((handle, view_id), view);
 901                    if handled {
 902                        return true;
 903                    }
 904                } else {
 905                    log::error!("view {} does not exist", view_id)
 906                }
 907            }
 908        }
 909
 910        false
 911    }
 912
 913    pub(crate) fn dispatch_key_up(&mut self, event: &KeyUpEvent) -> bool {
 914        let handle = self.window_handle;
 915        if let Some(focused_view_id) = self.window.focused_view_id {
 916            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 917                if let Some(mut view) = self.views.remove(&(handle, view_id)) {
 918                    let handled = view.key_up(event, self, view_id);
 919                    self.views.insert((handle, view_id), view);
 920                    if handled {
 921                        return true;
 922                    }
 923                } else {
 924                    log::error!("view {} does not exist", view_id)
 925                }
 926            }
 927        }
 928
 929        false
 930    }
 931
 932    pub(crate) fn dispatch_modifiers_changed(&mut self, event: &ModifiersChangedEvent) -> bool {
 933        let handle = self.window_handle;
 934        if let Some(focused_view_id) = self.window.focused_view_id {
 935            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 936                if let Some(mut view) = self.views.remove(&(handle, view_id)) {
 937                    let handled = view.modifiers_changed(event, self, view_id);
 938                    self.views.insert((handle, view_id), view);
 939                    if handled {
 940                        return true;
 941                    }
 942                } else {
 943                    log::error!("view {} does not exist", view_id)
 944                }
 945            }
 946        }
 947
 948        false
 949    }
 950
 951    pub fn invalidate(&mut self, mut invalidation: WindowInvalidation, appearance: Appearance) {
 952        self.start_frame();
 953        self.window.appearance = appearance;
 954        for view_id in &invalidation.removed {
 955            invalidation.updated.remove(view_id);
 956            self.window.rendered_views.remove(view_id);
 957        }
 958        for view_id in &invalidation.updated {
 959            let titlebar_height = self.window.titlebar_height;
 960            let element = self
 961                .render_view(RenderParams {
 962                    view_id: *view_id,
 963                    titlebar_height,
 964                    refreshing: false,
 965                    appearance,
 966                })
 967                .unwrap();
 968            self.window.rendered_views.insert(*view_id, element);
 969        }
 970    }
 971
 972    pub fn render_view(&mut self, params: RenderParams) -> Result<Box<dyn AnyRootElement>> {
 973        let handle = self.window_handle;
 974        let view_id = params.view_id;
 975        let mut view = self
 976            .views
 977            .remove(&(handle, view_id))
 978            .ok_or_else(|| anyhow!("view not found"))?;
 979        let element = view.render(self, view_id);
 980        self.views.insert((handle, view_id), view);
 981        Ok(element)
 982    }
 983
 984    pub fn layout(&mut self, refreshing: bool) -> Result<HashMap<usize, usize>> {
 985        let window_size = self.window.platform_window.content_size();
 986        let root_view_id = self.window.root_view().id();
 987
 988        let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
 989
 990        let mut new_parents = HashMap::default();
 991        let mut views_to_notify_if_ancestors_change = HashMap::default();
 992        rendered_root.layout(
 993            SizeConstraint::new(window_size, window_size),
 994            &mut new_parents,
 995            &mut views_to_notify_if_ancestors_change,
 996            refreshing,
 997            self,
 998        )?;
 999
1000        for (view_id, view_ids_to_notify) in views_to_notify_if_ancestors_change {
1001            let mut current_view_id = view_id;
1002            loop {
1003                let old_parent_id = self.window.parents.get(&current_view_id);
1004                let new_parent_id = new_parents.get(&current_view_id);
1005                if old_parent_id.is_none() && new_parent_id.is_none() {
1006                    break;
1007                } else if old_parent_id == new_parent_id {
1008                    current_view_id = *old_parent_id.unwrap();
1009                } else {
1010                    let handle = self.window_handle;
1011                    for view_id_to_notify in view_ids_to_notify {
1012                        self.notify_view(handle, view_id_to_notify);
1013                    }
1014                    break;
1015                }
1016            }
1017        }
1018
1019        let old_parents = mem::replace(&mut self.window.parents, new_parents);
1020        self.window
1021            .rendered_views
1022            .insert(root_view_id, rendered_root);
1023        Ok(old_parents)
1024    }
1025
1026    pub fn paint(&mut self) -> Result<Scene> {
1027        let window_size = self.window.platform_window.content_size();
1028        let scale_factor = self.window.platform_window.scale_factor();
1029
1030        let root_view_id = self.window.root_view().id();
1031        let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
1032
1033        let mut scene_builder = SceneBuilder::new(scale_factor);
1034        rendered_root.paint(
1035            &mut scene_builder,
1036            Vector2F::zero(),
1037            RectF::from_points(Vector2F::zero(), window_size),
1038            self,
1039        )?;
1040        self.window
1041            .rendered_views
1042            .insert(root_view_id, rendered_root);
1043
1044        self.window.text_layout_cache.finish_frame();
1045        let mut scene = scene_builder.build();
1046        self.window.cursor_regions = scene.cursor_regions();
1047        self.window.mouse_regions = scene.mouse_regions();
1048        self.window.event_handlers = scene.take_event_handlers();
1049
1050        if self.window_is_active() {
1051            if let Some(event) = self.window.last_mouse_moved_event.clone() {
1052                self.dispatch_event(event, true);
1053            }
1054        }
1055
1056        Ok(scene)
1057    }
1058
1059    pub fn root_element(&self) -> &Box<dyn AnyRootElement> {
1060        let view_id = self.window.root_view().id();
1061        self.window.rendered_views.get(&view_id).unwrap()
1062    }
1063
1064    pub fn rect_for_text_range(&self, range_utf16: Range<usize>) -> Option<RectF> {
1065        let focused_view_id = self.window.focused_view_id?;
1066        self.window
1067            .rendered_views
1068            .get(&focused_view_id)?
1069            .rect_for_text_range(range_utf16, self)
1070            .log_err()
1071            .flatten()
1072    }
1073
1074    pub fn set_window_title(&mut self, title: &str) {
1075        self.window.platform_window.set_title(title);
1076    }
1077
1078    pub fn set_window_edited(&mut self, edited: bool) {
1079        self.window.platform_window.set_edited(edited);
1080    }
1081
1082    pub fn is_topmost_window_for_position(&self, position: Vector2F) -> bool {
1083        self.window
1084            .platform_window
1085            .is_topmost_for_position(position)
1086    }
1087
1088    pub fn activate_window(&self) {
1089        self.window.platform_window.activate();
1090    }
1091
1092    pub fn window_is_active(&self) -> bool {
1093        self.window.is_active
1094    }
1095
1096    pub fn window_is_fullscreen(&self) -> bool {
1097        self.window.is_fullscreen
1098    }
1099
1100    pub(crate) fn dispatch_action(&mut self, view_id: Option<usize>, action: &dyn Action) -> bool {
1101        if let Some(view_id) = view_id {
1102            self.halt_action_dispatch = false;
1103            self.visit_dispatch_path(view_id, |view_id, capture_phase, cx| {
1104                cx.update_any_view(view_id, |view, cx| {
1105                    let type_id = view.as_any().type_id();
1106                    if let Some((name, mut handlers)) = cx
1107                        .actions_mut(capture_phase)
1108                        .get_mut(&type_id)
1109                        .and_then(|h| h.remove_entry(&action.id()))
1110                    {
1111                        for handler in handlers.iter_mut().rev() {
1112                            cx.halt_action_dispatch = true;
1113                            handler(view, action, cx, view_id);
1114                            if cx.halt_action_dispatch {
1115                                break;
1116                            }
1117                        }
1118                        cx.actions_mut(capture_phase)
1119                            .get_mut(&type_id)
1120                            .unwrap()
1121                            .insert(name, handlers);
1122                    }
1123                });
1124
1125                !cx.halt_action_dispatch
1126            });
1127        }
1128
1129        if !self.halt_action_dispatch {
1130            self.halt_action_dispatch = self.dispatch_global_action_any(action);
1131        }
1132
1133        self.pending_effects
1134            .push_back(Effect::ActionDispatchNotification {
1135                action_id: action.id(),
1136            });
1137        self.halt_action_dispatch
1138    }
1139
1140    /// Returns an iterator over all of the view ids from the passed view up to the root of the window
1141    /// Includes the passed view itself
1142    pub(crate) fn ancestors(&self, mut view_id: usize) -> impl Iterator<Item = usize> + '_ {
1143        std::iter::once(view_id)
1144            .into_iter()
1145            .chain(std::iter::from_fn(move || {
1146                if let Some(parent_id) = self.window.parents.get(&view_id) {
1147                    view_id = *parent_id;
1148                    Some(view_id)
1149                } else {
1150                    None
1151                }
1152            }))
1153    }
1154
1155    // Traverses the parent tree. Walks down the tree toward the passed
1156    // view calling visit with true. Then walks back up the tree calling visit with false.
1157    // If `visit` returns false this function will immediately return.
1158    fn visit_dispatch_path(
1159        &mut self,
1160        view_id: usize,
1161        mut visit: impl FnMut(usize, bool, &mut WindowContext) -> bool,
1162    ) {
1163        // List of view ids from the leaf to the root of the window
1164        let path = self.ancestors(view_id).collect::<Vec<_>>();
1165
1166        // Walk down from the root to the leaf calling visit with capture_phase = true
1167        for view_id in path.iter().rev() {
1168            if !visit(*view_id, true, self) {
1169                return;
1170            }
1171        }
1172
1173        // Walk up from the leaf to the root calling visit with capture_phase = false
1174        for view_id in path.iter() {
1175            if !visit(*view_id, false, self) {
1176                return;
1177            }
1178        }
1179    }
1180
1181    pub fn focused_view_id(&self) -> Option<usize> {
1182        self.window.focused_view_id
1183    }
1184
1185    pub fn focus(&mut self, view_id: Option<usize>) {
1186        self.app_context.focus(self.window_handle, view_id);
1187    }
1188
1189    pub fn window_bounds(&self) -> WindowBounds {
1190        self.window.platform_window.bounds()
1191    }
1192
1193    pub fn window_appearance(&self) -> Appearance {
1194        self.window.appearance
1195    }
1196
1197    pub fn window_display_uuid(&self) -> Option<Uuid> {
1198        self.window.platform_window.screen().display_uuid()
1199    }
1200
1201    pub fn show_character_palette(&self) {
1202        self.window.platform_window.show_character_palette();
1203    }
1204
1205    pub fn minimize_window(&self) {
1206        self.window.platform_window.minimize();
1207    }
1208
1209    pub fn zoom_window(&self) {
1210        self.window.platform_window.zoom();
1211    }
1212
1213    pub fn toggle_full_screen(&self) {
1214        self.window.platform_window.toggle_full_screen();
1215    }
1216
1217    pub fn prompt(
1218        &self,
1219        level: PromptLevel,
1220        msg: &str,
1221        answers: &[&str],
1222    ) -> oneshot::Receiver<usize> {
1223        self.window.platform_window.prompt(level, msg, answers)
1224    }
1225
1226    pub fn add_view<T, F>(&mut self, build_view: F) -> ViewHandle<T>
1227    where
1228        T: View,
1229        F: FnOnce(&mut ViewContext<T>) -> T,
1230    {
1231        self.add_option_view(|cx| Some(build_view(cx))).unwrap()
1232    }
1233
1234    pub fn add_option_view<T, F>(&mut self, build_view: F) -> Option<ViewHandle<T>>
1235    where
1236        T: View,
1237        F: FnOnce(&mut ViewContext<T>) -> Option<T>,
1238    {
1239        let handle = self.window_handle;
1240        let view_id = post_inc(&mut self.next_id);
1241        let mut cx = ViewContext::mutable(self, view_id);
1242        let handle = if let Some(view) = build_view(&mut cx) {
1243            let mut keymap_context = KeymapContext::default();
1244            view.update_keymap_context(&mut keymap_context, cx.app_context());
1245            self.views_metadata.insert(
1246                (handle, view_id),
1247                ViewMetadata {
1248                    type_id: TypeId::of::<T>(),
1249                    keymap_context,
1250                },
1251            );
1252            self.views.insert((handle, view_id), Box::new(view));
1253            self.window
1254                .invalidation
1255                .get_or_insert_with(Default::default)
1256                .updated
1257                .insert(view_id);
1258            Some(ViewHandle::new(handle, view_id, &self.ref_counts))
1259        } else {
1260            None
1261        };
1262        handle
1263    }
1264}
1265
1266#[derive(Default)]
1267pub struct LayoutEngine(Taffy);
1268pub use taffy::style::Style as LayoutStyle;
1269
1270impl LayoutEngine {
1271    pub fn new() -> Self {
1272        Default::default()
1273    }
1274
1275    pub fn add_node<C>(&mut self, style: LayoutStyle, children: C) -> Result<LayoutId>
1276    where
1277        C: IntoIterator<Item = LayoutId>,
1278    {
1279        let children = children.into_iter().collect::<Vec<_>>();
1280        if children.is_empty() {
1281            Ok(self.0.new_leaf(style)?)
1282        } else {
1283            Ok(self.0.new_with_children(style, &children)?)
1284        }
1285    }
1286
1287    pub fn add_measured_node<F>(&mut self, style: LayoutStyle, measure: F) -> Result<LayoutId>
1288    where
1289        F: Fn(MeasureParams) -> Size<f32> + Sync + Send + 'static,
1290    {
1291        Ok(self
1292            .0
1293            .new_leaf_with_measure(style, MeasureFunc::Boxed(Box::new(MeasureFn(measure))))?)
1294    }
1295
1296    pub fn compute_layout(&mut self, root: LayoutId, available_space: Vector2F) -> Result<()> {
1297        self.0.compute_layout(
1298            root,
1299            taffy::geometry::Size {
1300                width: available_space.x().into(),
1301                height: available_space.y().into(),
1302            },
1303        )?;
1304        Ok(())
1305    }
1306
1307    pub fn computed_layout(&mut self, node: LayoutId) -> Result<Layout> {
1308        Ok(Layout::from(self.0.layout(node)?))
1309    }
1310}
1311
1312pub struct MeasureFn<F>(F);
1313
1314impl<F: Send + Sync> Measurable for MeasureFn<F>
1315where
1316    F: Fn(MeasureParams) -> Size<f32>,
1317{
1318    fn measure(
1319        &self,
1320        known_dimensions: taffy::prelude::Size<Option<f32>>,
1321        available_space: taffy::prelude::Size<taffy::style::AvailableSpace>,
1322    ) -> taffy::prelude::Size<f32> {
1323        (self.0)(MeasureParams {
1324            known_dimensions: known_dimensions.into(),
1325            available_space: available_space.into(),
1326        })
1327        .into()
1328    }
1329}
1330
1331#[derive(Debug, Clone, Default)]
1332pub struct Layout {
1333    pub bounds: RectF,
1334    pub order: u32,
1335}
1336
1337pub struct MeasureParams {
1338    pub known_dimensions: Size<Option<f32>>,
1339    pub available_space: Size<AvailableSpace>,
1340}
1341
1342#[derive(Clone)]
1343pub enum AvailableSpace {
1344    /// The amount of space available is the specified number of pixels
1345    Pixels(f32),
1346    /// The amount of space available is indefinite and the node should be laid out under a min-content constraint
1347    MinContent,
1348    /// The amount of space available is indefinite and the node should be laid out under a max-content constraint
1349    MaxContent,
1350}
1351
1352impl Default for AvailableSpace {
1353    fn default() -> Self {
1354        Self::Pixels(0.)
1355    }
1356}
1357
1358impl From<taffy::prelude::AvailableSpace> for AvailableSpace {
1359    fn from(value: taffy::prelude::AvailableSpace) -> Self {
1360        match value {
1361            taffy::prelude::AvailableSpace::Definite(pixels) => Self::Pixels(pixels),
1362            taffy::prelude::AvailableSpace::MinContent => Self::MinContent,
1363            taffy::prelude::AvailableSpace::MaxContent => Self::MaxContent,
1364        }
1365    }
1366}
1367
1368impl From<&taffy::tree::Layout> for Layout {
1369    fn from(value: &taffy::tree::Layout) -> Self {
1370        Self {
1371            bounds: RectF::new(
1372                vec2f(value.location.x, value.location.y),
1373                vec2f(value.size.width, value.size.height),
1374            ),
1375            order: value.order,
1376        }
1377    }
1378}
1379
1380pub type LayoutId = taffy::prelude::NodeId;
1381
1382pub struct RenderParams {
1383    pub view_id: usize,
1384    pub titlebar_height: f32,
1385    pub refreshing: bool,
1386    pub appearance: Appearance,
1387}
1388
1389#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
1390pub enum Axis {
1391    #[default]
1392    Horizontal,
1393    Vertical,
1394}
1395
1396impl Axis {
1397    pub fn invert(self) -> Self {
1398        match self {
1399            Self::Horizontal => Self::Vertical,
1400            Self::Vertical => Self::Horizontal,
1401        }
1402    }
1403
1404    pub fn component(&self, point: Vector2F) -> f32 {
1405        match self {
1406            Self::Horizontal => point.x(),
1407            Self::Vertical => point.y(),
1408        }
1409    }
1410}
1411
1412impl ToJson for Axis {
1413    fn to_json(&self) -> serde_json::Value {
1414        match self {
1415            Axis::Horizontal => json!("horizontal"),
1416            Axis::Vertical => json!("vertical"),
1417        }
1418    }
1419}
1420
1421impl StaticColumnCount for Axis {}
1422impl Bind for Axis {
1423    fn bind(&self, statement: &Statement, start_index: i32) -> anyhow::Result<i32> {
1424        match self {
1425            Axis::Horizontal => "Horizontal",
1426            Axis::Vertical => "Vertical",
1427        }
1428        .bind(statement, start_index)
1429    }
1430}
1431
1432impl Column for Axis {
1433    fn column(statement: &mut Statement, start_index: i32) -> anyhow::Result<(Self, i32)> {
1434        String::column(statement, start_index).and_then(|(axis_text, next_index)| {
1435            Ok((
1436                match axis_text.as_str() {
1437                    "Horizontal" => Axis::Horizontal,
1438                    "Vertical" => Axis::Vertical,
1439                    _ => bail!("Stored serialized item kind is incorrect"),
1440                },
1441                next_index,
1442            ))
1443        })
1444    }
1445}
1446
1447pub trait Vector2FExt {
1448    fn along(self, axis: Axis) -> f32;
1449}
1450
1451impl Vector2FExt for Vector2F {
1452    fn along(self, axis: Axis) -> f32 {
1453        match axis {
1454            Axis::Horizontal => self.x(),
1455            Axis::Vertical => self.y(),
1456        }
1457    }
1458}
1459
1460pub trait RectFExt {
1461    fn length_along(self, axis: Axis) -> f32;
1462}
1463
1464impl RectFExt for RectF {
1465    fn length_along(self, axis: Axis) -> f32 {
1466        match axis {
1467            Axis::Horizontal => self.width(),
1468            Axis::Vertical => self.height(),
1469        }
1470    }
1471}
1472
1473#[derive(Copy, Clone, Debug)]
1474pub struct SizeConstraint {
1475    pub min: Vector2F,
1476    pub max: Vector2F,
1477}
1478
1479impl SizeConstraint {
1480    pub fn new(min: Vector2F, max: Vector2F) -> Self {
1481        Self { min, max }
1482    }
1483
1484    pub fn strict(size: Vector2F) -> Self {
1485        Self {
1486            min: size,
1487            max: size,
1488        }
1489    }
1490    pub fn loose(max: Vector2F) -> Self {
1491        Self {
1492            min: Vector2F::zero(),
1493            max,
1494        }
1495    }
1496
1497    pub fn strict_along(axis: Axis, max: f32) -> Self {
1498        match axis {
1499            Axis::Horizontal => Self {
1500                min: vec2f(max, 0.0),
1501                max: vec2f(max, f32::INFINITY),
1502            },
1503            Axis::Vertical => Self {
1504                min: vec2f(0.0, max),
1505                max: vec2f(f32::INFINITY, max),
1506            },
1507        }
1508    }
1509
1510    pub fn max_along(&self, axis: Axis) -> f32 {
1511        match axis {
1512            Axis::Horizontal => self.max.x(),
1513            Axis::Vertical => self.max.y(),
1514        }
1515    }
1516
1517    pub fn min_along(&self, axis: Axis) -> f32 {
1518        match axis {
1519            Axis::Horizontal => self.min.x(),
1520            Axis::Vertical => self.min.y(),
1521        }
1522    }
1523
1524    pub fn constrain(&self, size: Vector2F) -> Vector2F {
1525        vec2f(
1526            size.x().min(self.max.x()).max(self.min.x()),
1527            size.y().min(self.max.y()).max(self.min.y()),
1528        )
1529    }
1530}
1531
1532impl Sub<Vector2F> for SizeConstraint {
1533    type Output = SizeConstraint;
1534
1535    fn sub(self, rhs: Vector2F) -> SizeConstraint {
1536        SizeConstraint {
1537            min: self.min - rhs,
1538            max: self.max - rhs,
1539        }
1540    }
1541}
1542
1543impl Default for SizeConstraint {
1544    fn default() -> Self {
1545        SizeConstraint {
1546            min: Vector2F::zero(),
1547            max: Vector2F::splat(f32::INFINITY),
1548        }
1549    }
1550}
1551
1552impl ToJson for SizeConstraint {
1553    fn to_json(&self) -> serde_json::Value {
1554        json!({
1555            "min": self.min.to_json(),
1556            "max": self.max.to_json(),
1557        })
1558    }
1559}
1560
1561#[derive(Clone)]
1562pub struct ChildView {
1563    view_id: usize,
1564    view_name: &'static str,
1565}
1566
1567impl ChildView {
1568    pub fn new(view: &AnyViewHandle, cx: &AppContext) -> Self {
1569        let view_name = cx.view_ui_name(view.window, view.id()).unwrap();
1570        Self {
1571            view_id: view.id(),
1572            view_name,
1573        }
1574    }
1575}
1576
1577impl<V: 'static> Element<V> for ChildView {
1578    type LayoutState = ();
1579    type PaintState = ();
1580
1581    fn layout(
1582        &mut self,
1583        constraint: SizeConstraint,
1584        _: &mut V,
1585        cx: &mut LayoutContext<V>,
1586    ) -> (Vector2F, Self::LayoutState) {
1587        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1588            cx.new_parents.insert(self.view_id, cx.view_id());
1589            let size = rendered_view
1590                .layout(
1591                    constraint,
1592                    cx.new_parents,
1593                    cx.views_to_notify_if_ancestors_change,
1594                    cx.refreshing,
1595                    cx.view_context,
1596                )
1597                .log_err()
1598                .unwrap_or(Vector2F::zero());
1599            cx.window.rendered_views.insert(self.view_id, rendered_view);
1600            (size, ())
1601        } else {
1602            log::error!(
1603                "layout called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1604                self.view_id,
1605                self.view_name
1606            );
1607            (Vector2F::zero(), ())
1608        }
1609    }
1610
1611    fn paint(
1612        &mut self,
1613        scene: &mut SceneBuilder,
1614        bounds: RectF,
1615        visible_bounds: RectF,
1616        _: &mut Self::LayoutState,
1617        _: &mut V,
1618        cx: &mut PaintContext<V>,
1619    ) {
1620        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1621            rendered_view
1622                .paint(scene, bounds.origin(), visible_bounds, cx)
1623                .log_err();
1624            cx.window.rendered_views.insert(self.view_id, rendered_view);
1625        } else {
1626            log::error!(
1627                "paint called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1628                self.view_id,
1629                self.view_name
1630            );
1631        }
1632    }
1633
1634    fn rect_for_text_range(
1635        &self,
1636        range_utf16: Range<usize>,
1637        _: RectF,
1638        _: RectF,
1639        _: &Self::LayoutState,
1640        _: &Self::PaintState,
1641        _: &V,
1642        cx: &ViewContext<V>,
1643    ) -> Option<RectF> {
1644        if let Some(rendered_view) = cx.window.rendered_views.get(&self.view_id) {
1645            rendered_view
1646                .rect_for_text_range(range_utf16, &cx.window_context)
1647                .log_err()
1648                .flatten()
1649        } else {
1650            log::error!(
1651                "rect_for_text_range called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1652                self.view_id,
1653                self.view_name
1654            );
1655            None
1656        }
1657    }
1658
1659    fn debug(
1660        &self,
1661        bounds: RectF,
1662        _: &Self::LayoutState,
1663        _: &Self::PaintState,
1664        _: &V,
1665        cx: &ViewContext<V>,
1666    ) -> serde_json::Value {
1667        json!({
1668            "type": "ChildView",
1669            "bounds": bounds.to_json(),
1670            "child": if let Some(element) = cx.window.rendered_views.get(&self.view_id) {
1671                element.debug(&cx.window_context).log_err().unwrap_or_else(|| json!(null))
1672            } else {
1673                json!(null)
1674            }
1675        })
1676    }
1677}