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, InteractiveRegion, MouseClick, MouseClickOut, MouseDown, MouseDownOut,
  12        MouseDrag, MouseEvent, MouseHover, MouseMove, MouseMoveOut, MouseScrollWheel, MouseUp,
  13        MouseUpOut, 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    interactive_regions: Vec<InteractiveRegion>,
  61    last_mouse_moved_event: Option<Event>,
  62    pub(crate) hovered_region_ids: Vec<MouseRegionId>,
  63    pub(crate) clicked_region_ids: Vec<MouseRegionId>,
  64    pub(crate) clicked_region: Option<(MouseRegionId, MouseButton)>,
  65    mouse_position: Vector2F,
  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            interactive_regions: Vec::new(),
  95            text_layout_cache: TextLayoutCache::new(cx.font_system.clone()),
  96            last_mouse_moved_event: None,
  97            hovered_region_ids: Default::default(),
  98            clicked_region_ids: Default::default(),
  99            clicked_region: None,
 100            mouse_position: vec2f(0., 0.),
 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_interactive_regions(&mut self) -> Vec<InteractiveRegion> {
 123        mem::take(&mut self.interactive_regions)
 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 layout_engine(&mut self) -> Option<&mut LayoutEngine> {
 224        self.window.layout_engines.last_mut()
 225    }
 226
 227    pub fn push_layout_engine(&mut self, engine: LayoutEngine) {
 228        self.window.layout_engines.push(engine);
 229    }
 230
 231    pub fn pop_layout_engine(&mut self) -> Option<LayoutEngine> {
 232        self.window.layout_engines.pop()
 233    }
 234
 235    pub fn remove_window(&mut self) {
 236        self.removed = true;
 237    }
 238
 239    pub fn window(&self) -> AnyWindowHandle {
 240        self.window_handle
 241    }
 242
 243    pub fn app_context(&mut self) -> &mut AppContext {
 244        &mut self.app_context
 245    }
 246
 247    pub fn root_view(&self) -> &AnyViewHandle {
 248        self.window.root_view()
 249    }
 250
 251    pub fn window_size(&self) -> Vector2F {
 252        self.window.platform_window.content_size()
 253    }
 254
 255    pub fn text_layout_cache(&self) -> &TextLayoutCache {
 256        &self.window.text_layout_cache
 257    }
 258
 259    pub(crate) fn update_any_view<F, T>(&mut self, view_id: usize, f: F) -> Option<T>
 260    where
 261        F: FnOnce(&mut dyn AnyView, &mut Self) -> T,
 262    {
 263        let handle = self.window_handle;
 264        let mut view = self.views.remove(&(handle, view_id))?;
 265        let result = f(view.as_mut(), self);
 266        self.views.insert((handle, view_id), view);
 267        Some(result)
 268    }
 269
 270    pub(crate) fn update_view<V: 'static, S>(
 271        &mut self,
 272        handle: &ViewHandle<V>,
 273        update: &mut dyn FnMut(&mut V, &mut ViewContext<V>) -> S,
 274    ) -> S {
 275        self.update_any_view(handle.view_id, |view, cx| {
 276            let mut cx = ViewContext::mutable(cx, handle.view_id);
 277            update(
 278                view.as_any_mut()
 279                    .downcast_mut()
 280                    .expect("downcast is type safe"),
 281                &mut cx,
 282            )
 283        })
 284        .expect("view is already on the stack")
 285    }
 286
 287    pub fn defer(&mut self, callback: impl 'static + FnOnce(&mut WindowContext)) {
 288        let handle = self.window_handle;
 289        self.app_context.defer(move |cx| {
 290            cx.update_window(handle, |cx| callback(cx));
 291        })
 292    }
 293
 294    pub fn update_global<T, F, U>(&mut self, update: F) -> U
 295    where
 296        T: 'static,
 297        F: FnOnce(&mut T, &mut Self) -> U,
 298    {
 299        AppContext::update_global_internal(self, |global, cx| update(global, cx))
 300    }
 301
 302    pub fn update_default_global<T, F, U>(&mut self, update: F) -> U
 303    where
 304        T: 'static + Default,
 305        F: FnOnce(&mut T, &mut Self) -> U,
 306    {
 307        AppContext::update_default_global_internal(self, |global, cx| update(global, cx))
 308    }
 309
 310    pub fn subscribe<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
 311    where
 312        E: Entity,
 313        E::Event: 'static,
 314        H: Handle<E>,
 315        F: 'static + FnMut(H, &E::Event, &mut WindowContext),
 316    {
 317        self.subscribe_internal(handle, move |emitter, event, cx| {
 318            callback(emitter, event, cx);
 319            true
 320        })
 321    }
 322
 323    pub fn subscribe_internal<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
 324    where
 325        E: Entity,
 326        E::Event: 'static,
 327        H: Handle<E>,
 328        F: 'static + FnMut(H, &E::Event, &mut WindowContext) -> bool,
 329    {
 330        let window_handle = self.window_handle;
 331        self.app_context
 332            .subscribe_internal(handle, move |emitter, event, cx| {
 333                cx.update_window(window_handle, |cx| callback(emitter, event, cx))
 334                    .unwrap_or(false)
 335            })
 336    }
 337
 338    pub(crate) fn observe_window_activation<F>(&mut self, callback: F) -> Subscription
 339    where
 340        F: 'static + FnMut(bool, &mut WindowContext) -> bool,
 341    {
 342        let handle = self.window_handle;
 343        let subscription_id = post_inc(&mut self.next_subscription_id);
 344        self.pending_effects
 345            .push_back(Effect::WindowActivationObservation {
 346                window: handle,
 347                subscription_id,
 348                callback: Box::new(callback),
 349            });
 350        Subscription::WindowActivationObservation(
 351            self.window_activation_observations
 352                .subscribe(handle, subscription_id),
 353        )
 354    }
 355
 356    pub(crate) fn observe_fullscreen<F>(&mut self, callback: F) -> Subscription
 357    where
 358        F: 'static + FnMut(bool, &mut WindowContext) -> bool,
 359    {
 360        let window = self.window_handle;
 361        let subscription_id = post_inc(&mut self.next_subscription_id);
 362        self.pending_effects
 363            .push_back(Effect::WindowFullscreenObservation {
 364                window,
 365                subscription_id,
 366                callback: Box::new(callback),
 367            });
 368        Subscription::WindowActivationObservation(
 369            self.window_activation_observations
 370                .subscribe(window, subscription_id),
 371        )
 372    }
 373
 374    pub(crate) fn observe_window_bounds<F>(&mut self, callback: F) -> Subscription
 375    where
 376        F: 'static + FnMut(WindowBounds, Uuid, &mut WindowContext) -> bool,
 377    {
 378        let window = self.window_handle;
 379        let subscription_id = post_inc(&mut self.next_subscription_id);
 380        self.pending_effects
 381            .push_back(Effect::WindowBoundsObservation {
 382                window,
 383                subscription_id,
 384                callback: Box::new(callback),
 385            });
 386        Subscription::WindowBoundsObservation(
 387            self.window_bounds_observations
 388                .subscribe(window, subscription_id),
 389        )
 390    }
 391
 392    pub fn observe_keystrokes<F>(&mut self, callback: F) -> Subscription
 393    where
 394        F: 'static
 395            + FnMut(&Keystroke, &MatchResult, Option<&Box<dyn Action>>, &mut WindowContext) -> bool,
 396    {
 397        let window = self.window_handle;
 398        let subscription_id = post_inc(&mut self.next_subscription_id);
 399        self.keystroke_observations
 400            .add_callback(window, subscription_id, Box::new(callback));
 401        Subscription::KeystrokeObservation(
 402            self.keystroke_observations
 403                .subscribe(window, subscription_id),
 404        )
 405    }
 406
 407    pub(crate) fn available_actions(
 408        &self,
 409        view_id: usize,
 410    ) -> Vec<(&'static str, Box<dyn Action>, SmallVec<[Binding; 1]>)> {
 411        let handle = self.window_handle;
 412        let mut contexts = Vec::new();
 413        let mut handler_depths_by_action_id = HashMap::<TypeId, usize>::default();
 414        for (depth, view_id) in self.ancestors(view_id).enumerate() {
 415            if let Some(view_metadata) = self.views_metadata.get(&(handle, view_id)) {
 416                contexts.push(view_metadata.keymap_context.clone());
 417                if let Some(actions) = self.actions.get(&view_metadata.type_id) {
 418                    handler_depths_by_action_id
 419                        .extend(actions.keys().copied().map(|action_id| (action_id, depth)));
 420                }
 421            } else {
 422                log::error!(
 423                    "view {} not found when computing available actions",
 424                    view_id
 425                );
 426            }
 427        }
 428
 429        handler_depths_by_action_id.extend(
 430            self.global_actions
 431                .keys()
 432                .copied()
 433                .map(|action_id| (action_id, contexts.len())),
 434        );
 435
 436        self.action_deserializers
 437            .iter()
 438            .filter_map(move |(name, (action_id, deserialize))| {
 439                if let Some(action_depth) = handler_depths_by_action_id.get(action_id).copied() {
 440                    let action = deserialize(serde_json::Value::Object(Default::default())).ok()?;
 441                    let bindings = self
 442                        .keystroke_matcher
 443                        .bindings_for_action(*action_id)
 444                        .filter(|b| {
 445                            action.eq(b.action())
 446                                && (0..=action_depth)
 447                                    .any(|depth| b.match_context(&contexts[depth..]))
 448                        })
 449                        .cloned()
 450                        .collect();
 451                    Some((*name, action, bindings))
 452                } else {
 453                    None
 454                }
 455            })
 456            .collect()
 457    }
 458
 459    pub(crate) fn dispatch_keystroke(&mut self, keystroke: &Keystroke) -> bool {
 460        let handle = self.window_handle;
 461        if let Some(focused_view_id) = self.focused_view_id() {
 462            let dispatch_path = self
 463                .ancestors(focused_view_id)
 464                .filter_map(|view_id| {
 465                    self.views_metadata
 466                        .get(&(handle, view_id))
 467                        .map(|view| (view_id, view.keymap_context.clone()))
 468                })
 469                .collect();
 470
 471            let match_result = self
 472                .keystroke_matcher
 473                .push_keystroke(keystroke.clone(), dispatch_path);
 474            let mut handled_by = None;
 475
 476            let keystroke_handled = match &match_result {
 477                MatchResult::None => false,
 478                MatchResult::Pending => true,
 479                MatchResult::Matches(matches) => {
 480                    for (view_id, action) in matches {
 481                        if self.dispatch_action(Some(*view_id), action.as_ref()) {
 482                            self.keystroke_matcher.clear_pending();
 483                            handled_by = Some(action.boxed_clone());
 484                            break;
 485                        }
 486                    }
 487                    handled_by.is_some()
 488                }
 489            };
 490
 491            self.keystroke(handle, keystroke.clone(), handled_by, match_result.clone());
 492            keystroke_handled
 493        } else {
 494            self.keystroke(handle, keystroke.clone(), None, MatchResult::None);
 495            false
 496        }
 497    }
 498
 499    pub(crate) fn dispatch_event(&mut self, event: Event, event_reused: bool) -> bool {
 500        self.dispatch_to_interactive_regions(&event);
 501
 502        let mut mouse_events = SmallVec::<[_; 2]>::new();
 503        let mut notified_views: HashSet<usize> = Default::default();
 504        let handle = self.window_handle;
 505
 506        // 1. Handle platform event. Keyboard events get dispatched immediately, while mouse events
 507        //    get mapped into the mouse-specific MouseEvent type.
 508        //  -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
 509        //  -> Also updates mouse-related state
 510        match &event {
 511            Event::KeyDown(e) => return self.dispatch_key_down(e),
 512
 513            Event::KeyUp(e) => return self.dispatch_key_up(e),
 514
 515            Event::ModifiersChanged(e) => return self.dispatch_modifiers_changed(e),
 516
 517            Event::MouseDown(e) => {
 518                // Click events are weird because they can be fired after a drag event.
 519                // MDN says that browsers handle this by starting from 'the most
 520                // specific ancestor element that contained both [positions]'
 521                // So we need to store the overlapping regions on mouse down.
 522
 523                // If there is already region being clicked, don't replace it.
 524                if self.window.clicked_region.is_none() {
 525                    self.window.clicked_region_ids = self
 526                        .window
 527                        .mouse_regions
 528                        .iter()
 529                        .filter_map(|(region, _)| {
 530                            if region.bounds.contains_point(e.position) {
 531                                Some(region.id())
 532                            } else {
 533                                None
 534                            }
 535                        })
 536                        .collect();
 537
 538                    let mut highest_z_index = 0;
 539                    let mut clicked_region_id = None;
 540                    for (region, z_index) in self.window.mouse_regions.iter() {
 541                        if region.bounds.contains_point(e.position) && *z_index >= highest_z_index {
 542                            highest_z_index = *z_index;
 543                            clicked_region_id = Some(region.id());
 544                        }
 545                    }
 546
 547                    self.window.clicked_region =
 548                        clicked_region_id.map(|region_id| (region_id, e.button));
 549                }
 550
 551                mouse_events.push(MouseEvent::Down(MouseDown {
 552                    region: Default::default(),
 553                    platform_event: e.clone(),
 554                }));
 555                mouse_events.push(MouseEvent::DownOut(MouseDownOut {
 556                    region: Default::default(),
 557                    platform_event: e.clone(),
 558                }));
 559            }
 560
 561            Event::MouseUp(e) => {
 562                // NOTE: The order of event pushes is important! MouseUp events MUST be fired
 563                // before click events, and so the MouseUp events need to be pushed before
 564                // MouseClick events.
 565
 566                // Synthesize one last drag event to end the drag
 567                mouse_events.push(MouseEvent::Drag(MouseDrag {
 568                    region: Default::default(),
 569                    prev_mouse_position: self.window.mouse_position,
 570                    platform_event: MouseMovedEvent {
 571                        position: e.position,
 572                        pressed_button: Some(e.button),
 573                        modifiers: e.modifiers,
 574                    },
 575                    end: true,
 576                }));
 577                mouse_events.push(MouseEvent::Up(MouseUp {
 578                    region: Default::default(),
 579                    platform_event: e.clone(),
 580                }));
 581                mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 582                    region: Default::default(),
 583                    platform_event: e.clone(),
 584                }));
 585                mouse_events.push(MouseEvent::Click(MouseClick {
 586                    region: Default::default(),
 587                    platform_event: e.clone(),
 588                }));
 589                mouse_events.push(MouseEvent::ClickOut(MouseClickOut {
 590                    region: Default::default(),
 591                    platform_event: e.clone(),
 592                }));
 593            }
 594
 595            Event::MouseMoved(
 596                e @ MouseMovedEvent {
 597                    position,
 598                    pressed_button,
 599                    ..
 600                },
 601            ) => {
 602                let mut style_to_assign = CursorStyle::Arrow;
 603                for region in self.window.cursor_regions.iter().rev() {
 604                    if region.bounds.contains_point(*position) {
 605                        style_to_assign = region.style;
 606                        break;
 607                    }
 608                }
 609
 610                if self
 611                    .window
 612                    .platform_window
 613                    .is_topmost_for_position(*position)
 614                {
 615                    self.platform().set_cursor_style(style_to_assign);
 616                }
 617
 618                if !event_reused {
 619                    if pressed_button.is_some() {
 620                        mouse_events.push(MouseEvent::Drag(MouseDrag {
 621                            region: Default::default(),
 622                            prev_mouse_position: self.window.mouse_position,
 623                            platform_event: e.clone(),
 624                            end: false,
 625                        }));
 626                    } else if let Some((_, clicked_button)) = self.window.clicked_region {
 627                        mouse_events.push(MouseEvent::Drag(MouseDrag {
 628                            region: Default::default(),
 629                            prev_mouse_position: self.window.mouse_position,
 630                            platform_event: e.clone(),
 631                            end: true,
 632                        }));
 633
 634                        // Mouse up event happened outside the current window. Simulate mouse up button event
 635                        let button_event = e.to_button_event(clicked_button);
 636                        mouse_events.push(MouseEvent::Up(MouseUp {
 637                            region: Default::default(),
 638                            platform_event: button_event.clone(),
 639                        }));
 640                        mouse_events.push(MouseEvent::UpOut(MouseUpOut {
 641                            region: Default::default(),
 642                            platform_event: button_event.clone(),
 643                        }));
 644                        mouse_events.push(MouseEvent::Click(MouseClick {
 645                            region: Default::default(),
 646                            platform_event: button_event.clone(),
 647                        }));
 648                    }
 649
 650                    mouse_events.push(MouseEvent::Move(MouseMove {
 651                        region: Default::default(),
 652                        platform_event: e.clone(),
 653                    }));
 654                }
 655
 656                mouse_events.push(MouseEvent::Hover(MouseHover {
 657                    region: Default::default(),
 658                    platform_event: e.clone(),
 659                    started: false,
 660                }));
 661                mouse_events.push(MouseEvent::MoveOut(MouseMoveOut {
 662                    region: Default::default(),
 663                }));
 664
 665                self.window.last_mouse_moved_event = Some(event.clone());
 666            }
 667
 668            Event::MouseExited(event) => {
 669                // When the platform sends a MouseExited event, synthesize
 670                // a MouseMoved event whose position is outside the window's
 671                // bounds so that hover and cursor state can be updated.
 672                return self.dispatch_event(
 673                    Event::MouseMoved(MouseMovedEvent {
 674                        position: event.position,
 675                        pressed_button: event.pressed_button,
 676                        modifiers: event.modifiers,
 677                    }),
 678                    event_reused,
 679                );
 680            }
 681
 682            Event::ScrollWheel(e) => mouse_events.push(MouseEvent::ScrollWheel(MouseScrollWheel {
 683                region: Default::default(),
 684                platform_event: e.clone(),
 685            })),
 686        }
 687
 688        if let Some(position) = event.position() {
 689            self.window.mouse_position = position;
 690        }
 691
 692        // 2. Dispatch mouse events on regions
 693        let mut any_event_handled = false;
 694        for mut mouse_event in mouse_events {
 695            let mut valid_regions = Vec::new();
 696
 697            // GPUI elements are arranged by z_index but sibling elements can register overlapping
 698            // mouse regions. As such, hover events are only fired on overlapping elements which
 699            // are at the same z-index as the topmost element which overlaps with the mouse.
 700            match &mouse_event {
 701                MouseEvent::Hover(_) => {
 702                    let mut highest_z_index = None;
 703                    let mouse_position = self.window.mouse_position.clone();
 704                    let window = &mut *self.window;
 705                    let prev_hovered_regions = mem::take(&mut window.hovered_region_ids);
 706                    for (region, z_index) in window.mouse_regions.iter().rev() {
 707                        // Allow mouse regions to appear transparent to hovers
 708                        if !region.hoverable {
 709                            continue;
 710                        }
 711
 712                        let contains_mouse = region.bounds.contains_point(mouse_position);
 713
 714                        if contains_mouse && highest_z_index.is_none() {
 715                            highest_z_index = Some(z_index);
 716                        }
 717
 718                        // This unwrap relies on short circuiting boolean expressions
 719                        // The right side of the && is only executed when contains_mouse
 720                        // is true, and we know above that when contains_mouse is true
 721                        // highest_z_index is set.
 722                        if contains_mouse && z_index == highest_z_index.unwrap() {
 723                            //Ensure that hover entrance events aren't sent twice
 724                            if let Err(ix) = window.hovered_region_ids.binary_search(&region.id()) {
 725                                window.hovered_region_ids.insert(ix, region.id());
 726                            }
 727                            // window.hovered_region_ids.insert(region.id());
 728                            if !prev_hovered_regions.contains(&region.id()) {
 729                                valid_regions.push(region.clone());
 730                                if region.notify_on_hover {
 731                                    notified_views.insert(region.id().view_id());
 732                                }
 733                            }
 734                        } else {
 735                            // Ensure that hover exit events aren't sent twice
 736                            if prev_hovered_regions.contains(&region.id()) {
 737                                valid_regions.push(region.clone());
 738                                if region.notify_on_hover {
 739                                    notified_views.insert(region.id().view_id());
 740                                }
 741                            }
 742                        }
 743                    }
 744                }
 745
 746                MouseEvent::Down(_) | MouseEvent::Up(_) => {
 747                    for (region, _) in self.window.mouse_regions.iter().rev() {
 748                        if region.bounds.contains_point(self.window.mouse_position) {
 749                            valid_regions.push(region.clone());
 750                            if region.notify_on_click {
 751                                notified_views.insert(region.id().view_id());
 752                            }
 753                        }
 754                    }
 755                }
 756
 757                MouseEvent::Click(e) => {
 758                    // Only raise click events if the released button is the same as the one stored
 759                    if self
 760                        .window
 761                        .clicked_region
 762                        .map(|(_, clicked_button)| clicked_button == e.button)
 763                        .unwrap_or(false)
 764                    {
 765                        // Clear clicked regions and clicked button
 766                        let clicked_region_ids = std::mem::replace(
 767                            &mut self.window.clicked_region_ids,
 768                            Default::default(),
 769                        );
 770                        self.window.clicked_region = None;
 771
 772                        // Find regions which still overlap with the mouse since the last MouseDown happened
 773                        for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 774                            if clicked_region_ids.contains(&mouse_region.id()) {
 775                                if mouse_region
 776                                    .bounds
 777                                    .contains_point(self.window.mouse_position)
 778                                {
 779                                    valid_regions.push(mouse_region.clone());
 780                                }
 781                            }
 782                        }
 783                    }
 784                }
 785
 786                MouseEvent::Drag(_) => {
 787                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 788                        if self.window.clicked_region_ids.contains(&mouse_region.id()) {
 789                            valid_regions.push(mouse_region.clone());
 790                        }
 791                    }
 792                }
 793
 794                MouseEvent::MoveOut(_)
 795                | MouseEvent::UpOut(_)
 796                | MouseEvent::DownOut(_)
 797                | MouseEvent::ClickOut(_) => {
 798                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 799                        // NOT contains
 800                        if !mouse_region
 801                            .bounds
 802                            .contains_point(self.window.mouse_position)
 803                        {
 804                            valid_regions.push(mouse_region.clone());
 805                        }
 806                    }
 807                }
 808
 809                _ => {
 810                    for (mouse_region, _) in self.window.mouse_regions.iter().rev() {
 811                        // Contains
 812                        if mouse_region
 813                            .bounds
 814                            .contains_point(self.window.mouse_position)
 815                        {
 816                            valid_regions.push(mouse_region.clone());
 817                        }
 818                    }
 819                }
 820            }
 821
 822            //3. Fire region events
 823            let hovered_region_ids = self.window.hovered_region_ids.clone();
 824            for valid_region in valid_regions.into_iter() {
 825                let mut handled = false;
 826                mouse_event.set_region(valid_region.bounds);
 827                if let MouseEvent::Hover(e) = &mut mouse_event {
 828                    e.started = hovered_region_ids.contains(&valid_region.id())
 829                }
 830                // Handle Down events if the MouseRegion has a Click or Drag handler. This makes the api more intuitive as you would
 831                // not expect a MouseRegion to be transparent to Down events if it also has a Click handler.
 832                // This behavior can be overridden by adding a Down handler
 833                if let MouseEvent::Down(e) = &mouse_event {
 834                    let has_click = valid_region
 835                        .handlers
 836                        .contains(MouseEvent::click_disc(), Some(e.button));
 837                    let has_drag = valid_region
 838                        .handlers
 839                        .contains(MouseEvent::drag_disc(), Some(e.button));
 840                    let has_down = valid_region
 841                        .handlers
 842                        .contains(MouseEvent::down_disc(), Some(e.button));
 843                    if !has_down && (has_click || has_drag) {
 844                        handled = true;
 845                    }
 846                }
 847
 848                // `event_consumed` should only be true if there are any handlers for this event.
 849                let mut event_consumed = handled;
 850                if let Some(callbacks) = valid_region.handlers.get(&mouse_event.handler_key()) {
 851                    for callback in callbacks {
 852                        handled = true;
 853                        let view_id = valid_region.id().view_id();
 854                        self.update_any_view(view_id, |view, cx| {
 855                            handled = callback(mouse_event.clone(), view.as_any_mut(), cx, view_id);
 856                        });
 857                        event_consumed |= handled;
 858                        any_event_handled |= handled;
 859                    }
 860                }
 861
 862                any_event_handled |= handled;
 863
 864                // For bubbling events, if the event was handled, don't continue dispatching.
 865                // This only makes sense for local events which return false from is_capturable.
 866                if event_consumed && mouse_event.is_capturable() {
 867                    break;
 868                }
 869            }
 870        }
 871
 872        for view_id in notified_views {
 873            self.notify_view(handle, view_id);
 874        }
 875
 876        any_event_handled
 877    }
 878
 879    fn dispatch_to_interactive_regions(&mut self, event: &Event) {
 880        if let Some(mouse_event) = event.mouse_event() {
 881            let mouse_position = event.position().expect("mouse events must have a position");
 882            let interactive_regions = self.window.take_interactive_regions();
 883
 884            for region in interactive_regions.iter().rev() {
 885                if region.event_type == mouse_event.type_id() {
 886                    let in_bounds = region.bounds.contains_point(mouse_position);
 887
 888                    if in_bounds == !region.outside_bounds {
 889                        self.update_any_view(region.view_id, |view, window_cx| {
 890                            (region.event_handler)(
 891                                view.as_any_mut(),
 892                                mouse_event,
 893                                window_cx,
 894                                region.view_id,
 895                            )
 896                        });
 897                    }
 898                }
 899            }
 900
 901            self.window.interactive_regions = interactive_regions;
 902        }
 903    }
 904
 905    pub(crate) fn dispatch_key_down(&mut self, event: &KeyDownEvent) -> bool {
 906        let handle = self.window_handle;
 907        if let Some(focused_view_id) = self.window.focused_view_id {
 908            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 909                if let Some(mut view) = self.views.remove(&(handle, view_id)) {
 910                    let handled = view.key_down(event, self, view_id);
 911                    self.views.insert((handle, view_id), view);
 912                    if handled {
 913                        return true;
 914                    }
 915                } else {
 916                    log::error!("view {} does not exist", view_id)
 917                }
 918            }
 919        }
 920
 921        false
 922    }
 923
 924    pub(crate) fn dispatch_key_up(&mut self, event: &KeyUpEvent) -> bool {
 925        let handle = self.window_handle;
 926        if let Some(focused_view_id) = self.window.focused_view_id {
 927            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 928                if let Some(mut view) = self.views.remove(&(handle, view_id)) {
 929                    let handled = view.key_up(event, self, view_id);
 930                    self.views.insert((handle, view_id), view);
 931                    if handled {
 932                        return true;
 933                    }
 934                } else {
 935                    log::error!("view {} does not exist", view_id)
 936                }
 937            }
 938        }
 939
 940        false
 941    }
 942
 943    pub(crate) fn dispatch_modifiers_changed(&mut self, event: &ModifiersChangedEvent) -> bool {
 944        let handle = self.window_handle;
 945        if let Some(focused_view_id) = self.window.focused_view_id {
 946            for view_id in self.ancestors(focused_view_id).collect::<Vec<_>>() {
 947                if let Some(mut view) = self.views.remove(&(handle, view_id)) {
 948                    let handled = view.modifiers_changed(event, self, view_id);
 949                    self.views.insert((handle, view_id), view);
 950                    if handled {
 951                        return true;
 952                    }
 953                } else {
 954                    log::error!("view {} does not exist", view_id)
 955                }
 956            }
 957        }
 958
 959        false
 960    }
 961
 962    pub fn invalidate(&mut self, mut invalidation: WindowInvalidation, appearance: Appearance) {
 963        self.start_frame();
 964        self.window.appearance = appearance;
 965        for view_id in &invalidation.removed {
 966            invalidation.updated.remove(view_id);
 967            self.window.rendered_views.remove(view_id);
 968        }
 969        for view_id in &invalidation.updated {
 970            let titlebar_height = self.window.titlebar_height;
 971            let element = self
 972                .render_view(RenderParams {
 973                    view_id: *view_id,
 974                    titlebar_height,
 975                    refreshing: false,
 976                    appearance,
 977                })
 978                .unwrap();
 979            self.window.rendered_views.insert(*view_id, element);
 980        }
 981    }
 982
 983    pub fn render_view(&mut self, params: RenderParams) -> Result<Box<dyn AnyRootElement>> {
 984        let handle = self.window_handle;
 985        let view_id = params.view_id;
 986        let mut view = self
 987            .views
 988            .remove(&(handle, view_id))
 989            .ok_or_else(|| anyhow!("view not found"))?;
 990        let element = view.render(self, view_id);
 991        self.views.insert((handle, view_id), view);
 992        Ok(element)
 993    }
 994
 995    pub fn layout(&mut self, refreshing: bool) -> Result<HashMap<usize, usize>> {
 996        let window_size = self.window.platform_window.content_size();
 997        let root_view_id = self.window.root_view().id();
 998
 999        let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
1000
1001        let mut new_parents = HashMap::default();
1002        let mut views_to_notify_if_ancestors_change = HashMap::default();
1003        rendered_root.layout(
1004            SizeConstraint::new(window_size, window_size),
1005            &mut new_parents,
1006            &mut views_to_notify_if_ancestors_change,
1007            refreshing,
1008            self,
1009        )?;
1010
1011        for (view_id, view_ids_to_notify) in views_to_notify_if_ancestors_change {
1012            let mut current_view_id = view_id;
1013            loop {
1014                let old_parent_id = self.window.parents.get(&current_view_id);
1015                let new_parent_id = new_parents.get(&current_view_id);
1016                if old_parent_id.is_none() && new_parent_id.is_none() {
1017                    break;
1018                } else if old_parent_id == new_parent_id {
1019                    current_view_id = *old_parent_id.unwrap();
1020                } else {
1021                    let handle = self.window_handle;
1022                    for view_id_to_notify in view_ids_to_notify {
1023                        self.notify_view(handle, view_id_to_notify);
1024                    }
1025                    break;
1026                }
1027            }
1028        }
1029
1030        let old_parents = mem::replace(&mut self.window.parents, new_parents);
1031        self.window
1032            .rendered_views
1033            .insert(root_view_id, rendered_root);
1034        Ok(old_parents)
1035    }
1036
1037    pub fn paint(&mut self) -> Result<Scene> {
1038        let window_size = self.window.platform_window.content_size();
1039        let scale_factor = self.window.platform_window.scale_factor();
1040
1041        let root_view_id = self.window.root_view().id();
1042        let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
1043
1044        let mut scene_builder = SceneBuilder::new(scale_factor);
1045        rendered_root.paint(
1046            &mut scene_builder,
1047            Vector2F::zero(),
1048            RectF::from_points(Vector2F::zero(), window_size),
1049            self,
1050        )?;
1051        self.window
1052            .rendered_views
1053            .insert(root_view_id, rendered_root);
1054
1055        self.window.text_layout_cache.finish_frame();
1056        let mut scene = scene_builder.build();
1057        self.window.cursor_regions = scene.cursor_regions();
1058        self.window.mouse_regions = scene.mouse_regions();
1059        self.window.interactive_regions = scene.take_interactive_regions();
1060
1061        if self.window_is_active() {
1062            if let Some(event) = self.window.last_mouse_moved_event.clone() {
1063                self.dispatch_event(event, true);
1064            }
1065        }
1066
1067        Ok(scene)
1068    }
1069
1070    pub fn root_element(&self) -> &Box<dyn AnyRootElement> {
1071        let view_id = self.window.root_view().id();
1072        self.window.rendered_views.get(&view_id).unwrap()
1073    }
1074
1075    pub fn rect_for_text_range(&self, range_utf16: Range<usize>) -> Option<RectF> {
1076        let focused_view_id = self.window.focused_view_id?;
1077        self.window
1078            .rendered_views
1079            .get(&focused_view_id)?
1080            .rect_for_text_range(range_utf16, self)
1081            .log_err()
1082            .flatten()
1083    }
1084
1085    pub fn set_window_title(&mut self, title: &str) {
1086        self.window.platform_window.set_title(title);
1087    }
1088
1089    pub fn set_window_edited(&mut self, edited: bool) {
1090        self.window.platform_window.set_edited(edited);
1091    }
1092
1093    pub fn is_topmost_window_for_position(&self, position: Vector2F) -> bool {
1094        self.window
1095            .platform_window
1096            .is_topmost_for_position(position)
1097    }
1098
1099    pub fn activate_window(&self) {
1100        self.window.platform_window.activate();
1101    }
1102
1103    pub fn window_is_active(&self) -> bool {
1104        self.window.is_active
1105    }
1106
1107    pub fn window_is_fullscreen(&self) -> bool {
1108        self.window.is_fullscreen
1109    }
1110
1111    pub(crate) fn dispatch_action(&mut self, view_id: Option<usize>, action: &dyn Action) -> bool {
1112        if let Some(view_id) = view_id {
1113            self.halt_action_dispatch = false;
1114            self.visit_dispatch_path(view_id, |view_id, capture_phase, cx| {
1115                cx.update_any_view(view_id, |view, cx| {
1116                    let type_id = view.as_any().type_id();
1117                    if let Some((name, mut handlers)) = cx
1118                        .actions_mut(capture_phase)
1119                        .get_mut(&type_id)
1120                        .and_then(|h| h.remove_entry(&action.id()))
1121                    {
1122                        for handler in handlers.iter_mut().rev() {
1123                            cx.halt_action_dispatch = true;
1124                            handler(view, action, cx, view_id);
1125                            if cx.halt_action_dispatch {
1126                                break;
1127                            }
1128                        }
1129                        cx.actions_mut(capture_phase)
1130                            .get_mut(&type_id)
1131                            .unwrap()
1132                            .insert(name, handlers);
1133                    }
1134                });
1135
1136                !cx.halt_action_dispatch
1137            });
1138        }
1139
1140        if !self.halt_action_dispatch {
1141            self.halt_action_dispatch = self.dispatch_global_action_any(action);
1142        }
1143
1144        self.pending_effects
1145            .push_back(Effect::ActionDispatchNotification {
1146                action_id: action.id(),
1147            });
1148        self.halt_action_dispatch
1149    }
1150
1151    /// Returns an iterator over all of the view ids from the passed view up to the root of the window
1152    /// Includes the passed view itself
1153    pub(crate) fn ancestors(&self, mut view_id: usize) -> impl Iterator<Item = usize> + '_ {
1154        std::iter::once(view_id)
1155            .into_iter()
1156            .chain(std::iter::from_fn(move || {
1157                if let Some(parent_id) = self.window.parents.get(&view_id) {
1158                    view_id = *parent_id;
1159                    Some(view_id)
1160                } else {
1161                    None
1162                }
1163            }))
1164    }
1165
1166    // Traverses the parent tree. Walks down the tree toward the passed
1167    // view calling visit with true. Then walks back up the tree calling visit with false.
1168    // If `visit` returns false this function will immediately return.
1169    fn visit_dispatch_path(
1170        &mut self,
1171        view_id: usize,
1172        mut visit: impl FnMut(usize, bool, &mut WindowContext) -> bool,
1173    ) {
1174        // List of view ids from the leaf to the root of the window
1175        let path = self.ancestors(view_id).collect::<Vec<_>>();
1176
1177        // Walk down from the root to the leaf calling visit with capture_phase = true
1178        for view_id in path.iter().rev() {
1179            if !visit(*view_id, true, self) {
1180                return;
1181            }
1182        }
1183
1184        // Walk up from the leaf to the root calling visit with capture_phase = false
1185        for view_id in path.iter() {
1186            if !visit(*view_id, false, self) {
1187                return;
1188            }
1189        }
1190    }
1191
1192    pub fn focused_view_id(&self) -> Option<usize> {
1193        self.window.focused_view_id
1194    }
1195
1196    pub fn focus(&mut self, view_id: Option<usize>) {
1197        self.app_context.focus(self.window_handle, view_id);
1198    }
1199
1200    pub fn window_bounds(&self) -> WindowBounds {
1201        self.window.platform_window.bounds()
1202    }
1203
1204    pub fn window_appearance(&self) -> Appearance {
1205        self.window.appearance
1206    }
1207
1208    pub fn window_display_uuid(&self) -> Option<Uuid> {
1209        self.window.platform_window.screen().display_uuid()
1210    }
1211
1212    pub fn show_character_palette(&self) {
1213        self.window.platform_window.show_character_palette();
1214    }
1215
1216    pub fn minimize_window(&self) {
1217        self.window.platform_window.minimize();
1218    }
1219
1220    pub fn zoom_window(&self) {
1221        self.window.platform_window.zoom();
1222    }
1223
1224    pub fn toggle_full_screen(&self) {
1225        self.window.platform_window.toggle_full_screen();
1226    }
1227
1228    pub fn prompt(
1229        &self,
1230        level: PromptLevel,
1231        msg: &str,
1232        answers: &[&str],
1233    ) -> oneshot::Receiver<usize> {
1234        self.window.platform_window.prompt(level, msg, answers)
1235    }
1236
1237    pub fn add_view<T, F>(&mut self, build_view: F) -> ViewHandle<T>
1238    where
1239        T: View,
1240        F: FnOnce(&mut ViewContext<T>) -> T,
1241    {
1242        self.add_option_view(|cx| Some(build_view(cx))).unwrap()
1243    }
1244
1245    pub fn add_option_view<T, F>(&mut self, build_view: F) -> Option<ViewHandle<T>>
1246    where
1247        T: View,
1248        F: FnOnce(&mut ViewContext<T>) -> Option<T>,
1249    {
1250        let handle = self.window_handle;
1251        let view_id = post_inc(&mut self.next_id);
1252        let mut cx = ViewContext::mutable(self, view_id);
1253        let handle = if let Some(view) = build_view(&mut cx) {
1254            let mut keymap_context = KeymapContext::default();
1255            view.update_keymap_context(&mut keymap_context, cx.app_context());
1256            self.views_metadata.insert(
1257                (handle, view_id),
1258                ViewMetadata {
1259                    type_id: TypeId::of::<T>(),
1260                    keymap_context,
1261                },
1262            );
1263            self.views.insert((handle, view_id), Box::new(view));
1264            self.window
1265                .invalidation
1266                .get_or_insert_with(Default::default)
1267                .updated
1268                .insert(view_id);
1269            Some(ViewHandle::new(handle, view_id, &self.ref_counts))
1270        } else {
1271            None
1272        };
1273        handle
1274    }
1275}
1276
1277#[derive(Default)]
1278pub struct LayoutEngine(Taffy);
1279pub use taffy::style::Style as LayoutStyle;
1280
1281impl LayoutEngine {
1282    pub fn new() -> Self {
1283        Default::default()
1284    }
1285
1286    pub fn add_node<C>(&mut self, style: LayoutStyle, children: C) -> Result<LayoutNodeId>
1287    where
1288        C: IntoIterator<Item = LayoutNodeId>,
1289    {
1290        Ok(self
1291            .0
1292            .new_with_children(style, &children.into_iter().collect::<Vec<_>>())?)
1293    }
1294
1295    pub fn add_measured_node<F>(&mut self, style: LayoutStyle, measure: F) -> Result<LayoutNodeId>
1296    where
1297        F: Fn(MeasureParams) -> Size<f32> + Sync + Send + 'static,
1298    {
1299        Ok(self
1300            .0
1301            .new_leaf_with_measure(style, MeasureFunc::Boxed(Box::new(MeasureFn(measure))))?)
1302    }
1303
1304    pub fn compute_layout(&mut self, root: LayoutNodeId, available_space: Vector2F) -> Result<()> {
1305        self.0.compute_layout(
1306            root,
1307            taffy::geometry::Size {
1308                width: available_space.x().into(),
1309                height: available_space.y().into(),
1310            },
1311        )?;
1312        Ok(())
1313    }
1314
1315    pub fn computed_layout(&mut self, node: LayoutNodeId) -> Result<EngineLayout> {
1316        Ok(self.0.layout(node)?.into())
1317    }
1318}
1319
1320pub struct MeasureFn<F>(F);
1321
1322impl<F: Send + Sync> Measurable for MeasureFn<F>
1323where
1324    F: Fn(MeasureParams) -> Size<f32>,
1325{
1326    fn measure(
1327        &self,
1328        known_dimensions: taffy::prelude::Size<Option<f32>>,
1329        available_space: taffy::prelude::Size<taffy::style::AvailableSpace>,
1330    ) -> taffy::prelude::Size<f32> {
1331        (self.0)(MeasureParams {
1332            known_dimensions: known_dimensions.into(),
1333            available_space: available_space.into(),
1334        })
1335        .into()
1336    }
1337}
1338
1339#[derive(Debug, Clone)]
1340pub struct EngineLayout {
1341    pub bounds: RectF,
1342    pub order: u32,
1343}
1344
1345pub struct MeasureParams {
1346    pub known_dimensions: Size<Option<f32>>,
1347    pub available_space: Size<AvailableSpace>,
1348}
1349
1350pub enum AvailableSpace {
1351    /// The amount of space available is the specified number of pixels
1352    Pixels(f32),
1353    /// The amount of space available is indefinite and the node should be laid out under a min-content constraint
1354    MinContent,
1355    /// The amount of space available is indefinite and the node should be laid out under a max-content constraint
1356    MaxContent,
1357}
1358
1359impl From<taffy::prelude::AvailableSpace> for AvailableSpace {
1360    fn from(value: taffy::prelude::AvailableSpace) -> Self {
1361        match value {
1362            taffy::prelude::AvailableSpace::Definite(pixels) => Self::Pixels(pixels),
1363            taffy::prelude::AvailableSpace::MinContent => Self::MinContent,
1364            taffy::prelude::AvailableSpace::MaxContent => Self::MaxContent,
1365        }
1366    }
1367}
1368
1369impl From<&taffy::tree::Layout> for EngineLayout {
1370    fn from(value: &taffy::tree::Layout) -> Self {
1371        Self {
1372            bounds: RectF::new(
1373                vec2f(value.location.x, value.location.y),
1374                vec2f(value.size.width, value.size.height),
1375            ),
1376            order: value.order,
1377        }
1378    }
1379}
1380
1381pub type LayoutNodeId = taffy::prelude::NodeId;
1382
1383pub struct RenderParams {
1384    pub view_id: usize,
1385    pub titlebar_height: f32,
1386    pub refreshing: bool,
1387    pub appearance: Appearance,
1388}
1389
1390#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
1391pub enum Axis {
1392    #[default]
1393    Horizontal,
1394    Vertical,
1395}
1396
1397impl Axis {
1398    pub fn invert(self) -> Self {
1399        match self {
1400            Self::Horizontal => Self::Vertical,
1401            Self::Vertical => Self::Horizontal,
1402        }
1403    }
1404
1405    pub fn component(&self, point: Vector2F) -> f32 {
1406        match self {
1407            Self::Horizontal => point.x(),
1408            Self::Vertical => point.y(),
1409        }
1410    }
1411}
1412
1413impl ToJson for Axis {
1414    fn to_json(&self) -> serde_json::Value {
1415        match self {
1416            Axis::Horizontal => json!("horizontal"),
1417            Axis::Vertical => json!("vertical"),
1418        }
1419    }
1420}
1421
1422impl StaticColumnCount for Axis {}
1423impl Bind for Axis {
1424    fn bind(&self, statement: &Statement, start_index: i32) -> anyhow::Result<i32> {
1425        match self {
1426            Axis::Horizontal => "Horizontal",
1427            Axis::Vertical => "Vertical",
1428        }
1429        .bind(statement, start_index)
1430    }
1431}
1432
1433impl Column for Axis {
1434    fn column(statement: &mut Statement, start_index: i32) -> anyhow::Result<(Self, i32)> {
1435        String::column(statement, start_index).and_then(|(axis_text, next_index)| {
1436            Ok((
1437                match axis_text.as_str() {
1438                    "Horizontal" => Axis::Horizontal,
1439                    "Vertical" => Axis::Vertical,
1440                    _ => bail!("Stored serialized item kind is incorrect"),
1441                },
1442                next_index,
1443            ))
1444        })
1445    }
1446}
1447
1448pub trait Vector2FExt {
1449    fn along(self, axis: Axis) -> f32;
1450}
1451
1452impl Vector2FExt for Vector2F {
1453    fn along(self, axis: Axis) -> f32 {
1454        match axis {
1455            Axis::Horizontal => self.x(),
1456            Axis::Vertical => self.y(),
1457        }
1458    }
1459}
1460
1461pub trait RectFExt {
1462    fn length_along(self, axis: Axis) -> f32;
1463}
1464
1465impl RectFExt for RectF {
1466    fn length_along(self, axis: Axis) -> f32 {
1467        match axis {
1468            Axis::Horizontal => self.width(),
1469            Axis::Vertical => self.height(),
1470        }
1471    }
1472}
1473
1474#[derive(Copy, Clone, Debug)]
1475pub struct SizeConstraint {
1476    pub min: Vector2F,
1477    pub max: Vector2F,
1478}
1479
1480impl SizeConstraint {
1481    pub fn new(min: Vector2F, max: Vector2F) -> Self {
1482        Self { min, max }
1483    }
1484
1485    pub fn strict(size: Vector2F) -> Self {
1486        Self {
1487            min: size,
1488            max: size,
1489        }
1490    }
1491    pub fn loose(max: Vector2F) -> Self {
1492        Self {
1493            min: Vector2F::zero(),
1494            max,
1495        }
1496    }
1497
1498    pub fn strict_along(axis: Axis, max: f32) -> Self {
1499        match axis {
1500            Axis::Horizontal => Self {
1501                min: vec2f(max, 0.0),
1502                max: vec2f(max, f32::INFINITY),
1503            },
1504            Axis::Vertical => Self {
1505                min: vec2f(0.0, max),
1506                max: vec2f(f32::INFINITY, max),
1507            },
1508        }
1509    }
1510
1511    pub fn max_along(&self, axis: Axis) -> f32 {
1512        match axis {
1513            Axis::Horizontal => self.max.x(),
1514            Axis::Vertical => self.max.y(),
1515        }
1516    }
1517
1518    pub fn min_along(&self, axis: Axis) -> f32 {
1519        match axis {
1520            Axis::Horizontal => self.min.x(),
1521            Axis::Vertical => self.min.y(),
1522        }
1523    }
1524
1525    pub fn constrain(&self, size: Vector2F) -> Vector2F {
1526        vec2f(
1527            size.x().min(self.max.x()).max(self.min.x()),
1528            size.y().min(self.max.y()).max(self.min.y()),
1529        )
1530    }
1531}
1532
1533impl Sub<Vector2F> for SizeConstraint {
1534    type Output = SizeConstraint;
1535
1536    fn sub(self, rhs: Vector2F) -> SizeConstraint {
1537        SizeConstraint {
1538            min: self.min - rhs,
1539            max: self.max - rhs,
1540        }
1541    }
1542}
1543
1544impl Default for SizeConstraint {
1545    fn default() -> Self {
1546        SizeConstraint {
1547            min: Vector2F::zero(),
1548            max: Vector2F::splat(f32::INFINITY),
1549        }
1550    }
1551}
1552
1553impl ToJson for SizeConstraint {
1554    fn to_json(&self) -> serde_json::Value {
1555        json!({
1556            "min": self.min.to_json(),
1557            "max": self.max.to_json(),
1558        })
1559    }
1560}
1561
1562#[derive(Clone)]
1563pub struct ChildView {
1564    view_id: usize,
1565    view_name: &'static str,
1566}
1567
1568impl ChildView {
1569    pub fn new(view: &AnyViewHandle, cx: &AppContext) -> Self {
1570        let view_name = cx.view_ui_name(view.window, view.id()).unwrap();
1571        Self {
1572            view_id: view.id(),
1573            view_name,
1574        }
1575    }
1576}
1577
1578impl<V: 'static> Element<V> for ChildView {
1579    type LayoutState = ();
1580    type PaintState = ();
1581
1582    fn layout(
1583        &mut self,
1584        constraint: SizeConstraint,
1585        _: &mut V,
1586        cx: &mut LayoutContext<V>,
1587    ) -> (Vector2F, Self::LayoutState) {
1588        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1589            cx.new_parents.insert(self.view_id, cx.view_id());
1590            let size = rendered_view
1591                .layout(
1592                    constraint,
1593                    cx.new_parents,
1594                    cx.views_to_notify_if_ancestors_change,
1595                    cx.refreshing,
1596                    cx.view_context,
1597                )
1598                .log_err()
1599                .unwrap_or(Vector2F::zero());
1600            cx.window.rendered_views.insert(self.view_id, rendered_view);
1601            (size, ())
1602        } else {
1603            log::error!(
1604                "layout called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1605                self.view_id,
1606                self.view_name
1607            );
1608            (Vector2F::zero(), ())
1609        }
1610    }
1611
1612    fn paint(
1613        &mut self,
1614        scene: &mut SceneBuilder,
1615        bounds: RectF,
1616        visible_bounds: RectF,
1617        _: &mut Self::LayoutState,
1618        _: &mut V,
1619        cx: &mut PaintContext<V>,
1620    ) {
1621        if let Some(mut rendered_view) = cx.window.rendered_views.remove(&self.view_id) {
1622            rendered_view
1623                .paint(scene, bounds.origin(), visible_bounds, cx)
1624                .log_err();
1625            cx.window.rendered_views.insert(self.view_id, rendered_view);
1626        } else {
1627            log::error!(
1628                "paint called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1629                self.view_id,
1630                self.view_name
1631            );
1632        }
1633    }
1634
1635    fn rect_for_text_range(
1636        &self,
1637        range_utf16: Range<usize>,
1638        _: RectF,
1639        _: RectF,
1640        _: &Self::LayoutState,
1641        _: &Self::PaintState,
1642        _: &V,
1643        cx: &ViewContext<V>,
1644    ) -> Option<RectF> {
1645        if let Some(rendered_view) = cx.window.rendered_views.get(&self.view_id) {
1646            rendered_view
1647                .rect_for_text_range(range_utf16, &cx.window_context)
1648                .log_err()
1649                .flatten()
1650        } else {
1651            log::error!(
1652                "rect_for_text_range called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1653                self.view_id,
1654                self.view_name
1655            );
1656            None
1657        }
1658    }
1659
1660    fn debug(
1661        &self,
1662        bounds: RectF,
1663        _: &Self::LayoutState,
1664        _: &Self::PaintState,
1665        _: &V,
1666        cx: &ViewContext<V>,
1667    ) -> serde_json::Value {
1668        json!({
1669            "type": "ChildView",
1670            "bounds": bounds.to_json(),
1671            "child": if let Some(element) = cx.window.rendered_views.get(&self.view_id) {
1672                element.debug(&cx.window_context).log_err().unwrap_or_else(|| json!(null))
1673            } else {
1674                json!(null)
1675            }
1676        })
1677    }
1678}