div.rs

   1use crate::{
   2    point, px, Action, AnyDrag, AnyElement, AnyTooltip, AnyView, AppContext, BorrowAppContext,
   3    BorrowWindow, Bounds, ClickEvent, DispatchPhase, Element, ElementId, FocusEvent, FocusHandle,
   4    IntoElement, KeyContext, KeyDownEvent, KeyUpEvent, LayoutId, MouseButton, MouseDownEvent,
   5    MouseMoveEvent, MouseUpEvent, ParentElement, Pixels, Point, Render, ScrollWheelEvent,
   6    SharedString, Size, StackingOrder, Style, StyleRefinement, Styled, Task, View, Visibility,
   7    WindowContext,
   8};
   9
  10use collections::HashMap;
  11use refineable::Refineable;
  12use smallvec::SmallVec;
  13use std::{
  14    any::{Any, TypeId},
  15    cell::RefCell,
  16    cmp::Ordering,
  17    fmt::Debug,
  18    marker::PhantomData,
  19    mem,
  20    rc::Rc,
  21    time::Duration,
  22};
  23use taffy::style::Overflow;
  24use util::ResultExt;
  25
  26const DRAG_THRESHOLD: f64 = 2.;
  27const TOOLTIP_DELAY: Duration = Duration::from_millis(500);
  28
  29pub struct GroupStyle {
  30    pub group: SharedString,
  31    pub style: Box<StyleRefinement>,
  32}
  33
  34pub struct DragMoveEvent<T> {
  35    pub event: MouseMoveEvent,
  36    pub bounds: Bounds<Pixels>,
  37    drag: PhantomData<T>,
  38}
  39
  40impl<T: 'static> DragMoveEvent<T> {
  41    pub fn drag<'b>(&self, cx: &'b AppContext) -> &'b T {
  42        cx.active_drag
  43            .as_ref()
  44            .and_then(|drag| drag.value.downcast_ref::<T>())
  45            .expect("DragMoveEvent is only valid when the stored active drag is of the same type.")
  46    }
  47}
  48
  49pub trait InteractiveElement: Sized {
  50    fn interactivity(&mut self) -> &mut Interactivity;
  51
  52    fn group(mut self, group: impl Into<SharedString>) -> Self {
  53        self.interactivity().group = Some(group.into());
  54        self
  55    }
  56
  57    fn id(mut self, id: impl Into<ElementId>) -> Stateful<Self> {
  58        self.interactivity().element_id = Some(id.into());
  59
  60        Stateful { element: self }
  61    }
  62
  63    fn track_focus(mut self, focus_handle: &FocusHandle) -> Focusable<Self> {
  64        self.interactivity().focusable = true;
  65        self.interactivity().tracked_focus_handle = Some(focus_handle.clone());
  66        Focusable { element: self }
  67    }
  68
  69    fn key_context<C, E>(mut self, key_context: C) -> Self
  70    where
  71        C: TryInto<KeyContext, Error = E>,
  72        E: Debug,
  73    {
  74        if let Some(key_context) = key_context.try_into().log_err() {
  75            self.interactivity().key_context = Some(key_context);
  76        }
  77        self
  78    }
  79
  80    fn hover(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self {
  81        debug_assert!(
  82            self.interactivity().hover_style.is_none(),
  83            "hover style already set"
  84        );
  85        self.interactivity().hover_style = Some(Box::new(f(StyleRefinement::default())));
  86        self
  87    }
  88
  89    fn group_hover(
  90        mut self,
  91        group_name: impl Into<SharedString>,
  92        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
  93    ) -> Self {
  94        self.interactivity().group_hover_style = Some(GroupStyle {
  95            group: group_name.into(),
  96            style: Box::new(f(StyleRefinement::default())),
  97        });
  98        self
  99    }
 100
 101    fn on_mouse_down(
 102        mut self,
 103        button: MouseButton,
 104        listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
 105    ) -> Self {
 106        self.interactivity().mouse_down_listeners.push(Box::new(
 107            move |event, bounds, phase, cx| {
 108                if phase == DispatchPhase::Bubble
 109                    && event.button == button
 110                    && bounds.visibly_contains(&event.position, cx)
 111                {
 112                    (listener)(event, cx)
 113                }
 114            },
 115        ));
 116        self
 117    }
 118
 119    fn on_any_mouse_down(
 120        mut self,
 121        listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
 122    ) -> Self {
 123        self.interactivity().mouse_down_listeners.push(Box::new(
 124            move |event, bounds, phase, cx| {
 125                if phase == DispatchPhase::Bubble && bounds.visibly_contains(&event.position, cx) {
 126                    (listener)(event, cx)
 127                }
 128            },
 129        ));
 130        self
 131    }
 132
 133    fn on_mouse_up(
 134        mut self,
 135        button: MouseButton,
 136        listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
 137    ) -> Self {
 138        self.interactivity()
 139            .mouse_up_listeners
 140            .push(Box::new(move |event, bounds, phase, cx| {
 141                if phase == DispatchPhase::Bubble
 142                    && event.button == button
 143                    && bounds.visibly_contains(&event.position, cx)
 144                {
 145                    (listener)(event, cx)
 146                }
 147            }));
 148        self
 149    }
 150
 151    fn on_any_mouse_up(
 152        mut self,
 153        listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
 154    ) -> Self {
 155        self.interactivity()
 156            .mouse_up_listeners
 157            .push(Box::new(move |event, bounds, phase, cx| {
 158                if phase == DispatchPhase::Bubble && bounds.visibly_contains(&event.position, cx) {
 159                    (listener)(event, cx)
 160                }
 161            }));
 162        self
 163    }
 164
 165    fn on_mouse_down_out(
 166        mut self,
 167        listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
 168    ) -> Self {
 169        self.interactivity().mouse_down_listeners.push(Box::new(
 170            move |event, bounds, phase, cx| {
 171                if phase == DispatchPhase::Capture && !bounds.visibly_contains(&event.position, cx)
 172                {
 173                    (listener)(event, cx)
 174                }
 175            },
 176        ));
 177        self
 178    }
 179
 180    fn on_mouse_up_out(
 181        mut self,
 182        button: MouseButton,
 183        listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
 184    ) -> Self {
 185        self.interactivity()
 186            .mouse_up_listeners
 187            .push(Box::new(move |event, bounds, phase, cx| {
 188                if phase == DispatchPhase::Capture
 189                    && event.button == button
 190                    && !bounds.visibly_contains(&event.position, cx)
 191                {
 192                    (listener)(event, cx);
 193                }
 194            }));
 195        self
 196    }
 197
 198    fn on_mouse_move(
 199        mut self,
 200        listener: impl Fn(&MouseMoveEvent, &mut WindowContext) + 'static,
 201    ) -> Self {
 202        self.interactivity().mouse_move_listeners.push(Box::new(
 203            move |event, bounds, phase, cx| {
 204                if phase == DispatchPhase::Bubble && bounds.visibly_contains(&event.position, cx) {
 205                    (listener)(event, cx);
 206                }
 207            },
 208        ));
 209        self
 210    }
 211
 212    fn on_drag_move<T: 'static>(
 213        mut self,
 214        listener: impl Fn(&DragMoveEvent<T>, &mut WindowContext) + 'static,
 215    ) -> Self
 216    where
 217        T: 'static,
 218    {
 219        self.interactivity().mouse_move_listeners.push(Box::new(
 220            move |event, bounds, phase, cx| {
 221                if phase == DispatchPhase::Capture
 222                    && bounds.drag_target_contains(&event.position, cx)
 223                {
 224                    if cx
 225                        .active_drag
 226                        .as_ref()
 227                        .is_some_and(|drag| drag.value.as_ref().type_id() == TypeId::of::<T>())
 228                    {
 229                        (listener)(
 230                            &DragMoveEvent {
 231                                event: event.clone(),
 232                                bounds: bounds.bounds,
 233                                drag: PhantomData,
 234                            },
 235                            cx,
 236                        );
 237                    }
 238                }
 239            },
 240        ));
 241        self
 242    }
 243
 244    fn on_scroll_wheel(
 245        mut self,
 246        listener: impl Fn(&ScrollWheelEvent, &mut WindowContext) + 'static,
 247    ) -> Self {
 248        self.interactivity().scroll_wheel_listeners.push(Box::new(
 249            move |event, bounds, phase, cx| {
 250                if phase == DispatchPhase::Bubble && bounds.visibly_contains(&event.position, cx) {
 251                    (listener)(event, cx);
 252                }
 253            },
 254        ));
 255        self
 256    }
 257
 258    /// Capture the given action, before normal action dispatch can fire
 259    fn capture_action<A: Action>(
 260        mut self,
 261        listener: impl Fn(&A, &mut WindowContext) + 'static,
 262    ) -> Self {
 263        self.interactivity().action_listeners.push((
 264            TypeId::of::<A>(),
 265            Box::new(move |action, phase, cx| {
 266                let action = action.downcast_ref().unwrap();
 267                if phase == DispatchPhase::Capture {
 268                    (listener)(action, cx)
 269                }
 270            }),
 271        ));
 272        self
 273    }
 274
 275    /// Add a listener for the given action, fires during the bubble event phase
 276    fn on_action<A: Action>(mut self, listener: impl Fn(&A, &mut WindowContext) + 'static) -> Self {
 277        self.interactivity().action_listeners.push((
 278            TypeId::of::<A>(),
 279            Box::new(move |action, phase, cx| {
 280                let action = action.downcast_ref().unwrap();
 281                if phase == DispatchPhase::Bubble {
 282                    (listener)(action, cx)
 283                }
 284            }),
 285        ));
 286        self
 287    }
 288
 289    fn on_boxed_action(
 290        mut self,
 291        action: &Box<dyn Action>,
 292        listener: impl Fn(&Box<dyn Action>, &mut WindowContext) + 'static,
 293    ) -> Self {
 294        let action = action.boxed_clone();
 295        self.interactivity().action_listeners.push((
 296            (*action).type_id(),
 297            Box::new(move |_, phase, cx| {
 298                if phase == DispatchPhase::Bubble {
 299                    (listener)(&action, cx)
 300                }
 301            }),
 302        ));
 303        self
 304    }
 305
 306    fn on_key_down(
 307        mut self,
 308        listener: impl Fn(&KeyDownEvent, &mut WindowContext) + 'static,
 309    ) -> Self {
 310        self.interactivity()
 311            .key_down_listeners
 312            .push(Box::new(move |event, phase, cx| {
 313                if phase == DispatchPhase::Bubble {
 314                    (listener)(event, cx)
 315                }
 316            }));
 317        self
 318    }
 319
 320    fn capture_key_down(
 321        mut self,
 322        listener: impl Fn(&KeyDownEvent, &mut WindowContext) + 'static,
 323    ) -> Self {
 324        self.interactivity()
 325            .key_down_listeners
 326            .push(Box::new(move |event, phase, cx| {
 327                if phase == DispatchPhase::Capture {
 328                    listener(event, cx)
 329                }
 330            }));
 331        self
 332    }
 333
 334    fn on_key_up(mut self, listener: impl Fn(&KeyUpEvent, &mut WindowContext) + 'static) -> Self {
 335        self.interactivity()
 336            .key_up_listeners
 337            .push(Box::new(move |event, phase, cx| {
 338                if phase == DispatchPhase::Bubble {
 339                    listener(event, cx)
 340                }
 341            }));
 342        self
 343    }
 344
 345    fn capture_key_up(
 346        mut self,
 347        listener: impl Fn(&KeyUpEvent, &mut WindowContext) + 'static,
 348    ) -> Self {
 349        self.interactivity()
 350            .key_up_listeners
 351            .push(Box::new(move |event, phase, cx| {
 352                if phase == DispatchPhase::Capture {
 353                    listener(event, cx)
 354                }
 355            }));
 356        self
 357    }
 358
 359    fn drag_over<S: 'static>(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self {
 360        self.interactivity()
 361            .drag_over_styles
 362            .push((TypeId::of::<S>(), f(StyleRefinement::default())));
 363        self
 364    }
 365
 366    fn group_drag_over<S: 'static>(
 367        mut self,
 368        group_name: impl Into<SharedString>,
 369        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
 370    ) -> Self {
 371        self.interactivity().group_drag_over_styles.push((
 372            TypeId::of::<S>(),
 373            GroupStyle {
 374                group: group_name.into(),
 375                style: Box::new(f(StyleRefinement::default())),
 376            },
 377        ));
 378        self
 379    }
 380
 381    fn on_drop<T: 'static>(mut self, listener: impl Fn(&T, &mut WindowContext) + 'static) -> Self {
 382        self.interactivity().drop_listeners.push((
 383            TypeId::of::<T>(),
 384            Box::new(move |dragged_value, cx| {
 385                listener(dragged_value.downcast_ref().unwrap(), cx);
 386            }),
 387        ));
 388        self
 389    }
 390}
 391
 392pub trait StatefulInteractiveElement: InteractiveElement {
 393    fn focusable(mut self) -> Focusable<Self> {
 394        self.interactivity().focusable = true;
 395        Focusable { element: self }
 396    }
 397
 398    fn overflow_scroll(mut self) -> Self {
 399        self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
 400        self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
 401        self
 402    }
 403
 404    fn overflow_x_scroll(mut self) -> Self {
 405        self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
 406        self
 407    }
 408
 409    fn overflow_y_scroll(mut self) -> Self {
 410        self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
 411        self
 412    }
 413
 414    fn track_scroll(mut self, scroll_handle: &ScrollHandle) -> Self {
 415        self.interactivity().scroll_handle = Some(scroll_handle.clone());
 416        self
 417    }
 418
 419    fn active(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
 420    where
 421        Self: Sized,
 422    {
 423        self.interactivity().active_style = Some(Box::new(f(StyleRefinement::default())));
 424        self
 425    }
 426
 427    fn group_active(
 428        mut self,
 429        group_name: impl Into<SharedString>,
 430        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
 431    ) -> Self
 432    where
 433        Self: Sized,
 434    {
 435        self.interactivity().group_active_style = Some(GroupStyle {
 436            group: group_name.into(),
 437            style: Box::new(f(StyleRefinement::default())),
 438        });
 439        self
 440    }
 441
 442    fn on_click(mut self, listener: impl Fn(&ClickEvent, &mut WindowContext) + 'static) -> Self
 443    where
 444        Self: Sized,
 445    {
 446        self.interactivity()
 447            .click_listeners
 448            .push(Box::new(move |event, cx| listener(event, cx)));
 449        self
 450    }
 451
 452    fn on_drag<T, W>(
 453        mut self,
 454        value: T,
 455        constructor: impl Fn(&T, &mut WindowContext) -> View<W> + 'static,
 456    ) -> Self
 457    where
 458        Self: Sized,
 459        T: 'static,
 460        W: 'static + Render,
 461    {
 462        debug_assert!(
 463            self.interactivity().drag_listener.is_none(),
 464            "calling on_drag more than once on the same element is not supported"
 465        );
 466        self.interactivity().drag_listener = Some((
 467            Box::new(value),
 468            Box::new(move |value, cx| constructor(value.downcast_ref().unwrap(), cx).into()),
 469        ));
 470        self
 471    }
 472
 473    fn on_hover(mut self, listener: impl Fn(&bool, &mut WindowContext) + 'static) -> Self
 474    where
 475        Self: Sized,
 476    {
 477        debug_assert!(
 478            self.interactivity().hover_listener.is_none(),
 479            "calling on_hover more than once on the same element is not supported"
 480        );
 481        self.interactivity().hover_listener = Some(Box::new(listener));
 482        self
 483    }
 484
 485    fn tooltip(mut self, build_tooltip: impl Fn(&mut WindowContext) -> AnyView + 'static) -> Self
 486    where
 487        Self: Sized,
 488    {
 489        debug_assert!(
 490            self.interactivity().tooltip_builder.is_none(),
 491            "calling tooltip more than once on the same element is not supported"
 492        );
 493        self.interactivity().tooltip_builder = Some(Rc::new(build_tooltip));
 494        self
 495    }
 496}
 497
 498pub trait FocusableElement: InteractiveElement {
 499    fn focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
 500    where
 501        Self: Sized,
 502    {
 503        self.interactivity().focus_style = Some(Box::new(f(StyleRefinement::default())));
 504        self
 505    }
 506
 507    fn in_focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
 508    where
 509        Self: Sized,
 510    {
 511        self.interactivity().in_focus_style = Some(Box::new(f(StyleRefinement::default())));
 512        self
 513    }
 514}
 515
 516pub type FocusListeners = Vec<FocusListener>;
 517
 518pub type FocusListener = Box<dyn Fn(&FocusHandle, &FocusEvent, &mut WindowContext) + 'static>;
 519
 520pub type MouseDownListener =
 521    Box<dyn Fn(&MouseDownEvent, &InteractiveBounds, DispatchPhase, &mut WindowContext) + 'static>;
 522pub type MouseUpListener =
 523    Box<dyn Fn(&MouseUpEvent, &InteractiveBounds, DispatchPhase, &mut WindowContext) + 'static>;
 524
 525pub type MouseMoveListener =
 526    Box<dyn Fn(&MouseMoveEvent, &InteractiveBounds, DispatchPhase, &mut WindowContext) + 'static>;
 527
 528pub type ScrollWheelListener =
 529    Box<dyn Fn(&ScrollWheelEvent, &InteractiveBounds, DispatchPhase, &mut WindowContext) + 'static>;
 530
 531pub type ClickListener = Box<dyn Fn(&ClickEvent, &mut WindowContext) + 'static>;
 532
 533pub type DragListener = Box<dyn Fn(&dyn Any, &mut WindowContext) -> AnyView + 'static>;
 534
 535type DropListener = Box<dyn Fn(&dyn Any, &mut WindowContext) + 'static>;
 536
 537pub type TooltipBuilder = Rc<dyn Fn(&mut WindowContext) -> AnyView + 'static>;
 538
 539pub type KeyDownListener = Box<dyn Fn(&KeyDownEvent, DispatchPhase, &mut WindowContext) + 'static>;
 540
 541pub type KeyUpListener = Box<dyn Fn(&KeyUpEvent, DispatchPhase, &mut WindowContext) + 'static>;
 542
 543pub type DragEventListener = Box<dyn Fn(&MouseMoveEvent, &mut WindowContext) + 'static>;
 544
 545pub type ActionListener = Box<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
 546
 547#[track_caller]
 548pub fn div() -> Div {
 549    #[cfg(debug_assertions)]
 550    let interactivity = {
 551        let mut interactivity = Interactivity::default();
 552        interactivity.location = Some(*core::panic::Location::caller());
 553        interactivity
 554    };
 555
 556    #[cfg(not(debug_assertions))]
 557    let interactivity = Interactivity::default();
 558
 559    Div {
 560        interactivity,
 561        children: SmallVec::default(),
 562    }
 563}
 564
 565pub struct Div {
 566    interactivity: Interactivity,
 567    children: SmallVec<[AnyElement; 2]>,
 568}
 569
 570impl Styled for Div {
 571    fn style(&mut self) -> &mut StyleRefinement {
 572        &mut self.interactivity.base_style
 573    }
 574}
 575
 576impl InteractiveElement for Div {
 577    fn interactivity(&mut self) -> &mut Interactivity {
 578        &mut self.interactivity
 579    }
 580}
 581
 582impl ParentElement for Div {
 583    fn children_mut(&mut self) -> &mut SmallVec<[AnyElement; 2]> {
 584        &mut self.children
 585    }
 586}
 587
 588impl Element for Div {
 589    type State = DivState;
 590
 591    fn layout(
 592        &mut self,
 593        element_state: Option<Self::State>,
 594        cx: &mut WindowContext,
 595    ) -> (LayoutId, Self::State) {
 596        let mut child_layout_ids = SmallVec::new();
 597        let (layout_id, interactive_state) = self.interactivity.layout(
 598            element_state.map(|s| s.interactive_state),
 599            cx,
 600            |style, cx| {
 601                cx.with_text_style(style.text_style().cloned(), |cx| {
 602                    child_layout_ids = self
 603                        .children
 604                        .iter_mut()
 605                        .map(|child| child.layout(cx))
 606                        .collect::<SmallVec<_>>();
 607                    cx.request_layout(&style, child_layout_ids.iter().copied())
 608                })
 609            },
 610        );
 611        (
 612            layout_id,
 613            DivState {
 614                interactive_state,
 615                child_layout_ids,
 616            },
 617        )
 618    }
 619
 620    fn paint(
 621        self,
 622        bounds: Bounds<Pixels>,
 623        element_state: &mut Self::State,
 624        cx: &mut WindowContext,
 625    ) {
 626        let mut child_min = point(Pixels::MAX, Pixels::MAX);
 627        let mut child_max = Point::default();
 628        let content_size = if element_state.child_layout_ids.is_empty() {
 629            bounds.size
 630        } else if let Some(scroll_handle) = self.interactivity.scroll_handle.as_ref() {
 631            let mut state = scroll_handle.0.borrow_mut();
 632            state.child_bounds = Vec::with_capacity(element_state.child_layout_ids.len());
 633            state.bounds = bounds;
 634            let requested = state.requested_scroll_top.take();
 635
 636            for (ix, child_layout_id) in element_state.child_layout_ids.iter().enumerate() {
 637                let child_bounds = cx.layout_bounds(*child_layout_id);
 638                child_min = child_min.min(&child_bounds.origin);
 639                child_max = child_max.max(&child_bounds.lower_right());
 640                state.child_bounds.push(child_bounds);
 641
 642                if let Some(requested) = requested.as_ref() {
 643                    if requested.0 == ix {
 644                        *state.offset.borrow_mut() =
 645                            bounds.origin - (child_bounds.origin - point(px(0.), requested.1));
 646                    }
 647                }
 648            }
 649            (child_max - child_min).into()
 650        } else {
 651            for child_layout_id in &element_state.child_layout_ids {
 652                let child_bounds = cx.layout_bounds(*child_layout_id);
 653                child_min = child_min.min(&child_bounds.origin);
 654                child_max = child_max.max(&child_bounds.lower_right());
 655            }
 656            (child_max - child_min).into()
 657        };
 658
 659        self.interactivity.paint(
 660            bounds,
 661            content_size,
 662            &mut element_state.interactive_state,
 663            cx,
 664            |style, scroll_offset, cx| {
 665                let z_index = style.z_index.unwrap_or(0);
 666
 667                cx.with_z_index(z_index, |cx| {
 668                    style.paint(bounds, cx, |cx| {
 669                        cx.with_text_style(style.text_style().cloned(), |cx| {
 670                            cx.with_content_mask(style.overflow_mask(bounds), |cx| {
 671                                cx.with_element_offset(scroll_offset, |cx| {
 672                                    for child in self.children {
 673                                        child.paint(cx);
 674                                    }
 675                                })
 676                            })
 677                        })
 678                    });
 679                })
 680            },
 681        );
 682    }
 683}
 684
 685impl IntoElement for Div {
 686    type Element = Self;
 687
 688    fn element_id(&self) -> Option<ElementId> {
 689        self.interactivity.element_id.clone()
 690    }
 691
 692    fn into_element(self) -> Self::Element {
 693        self
 694    }
 695}
 696
 697pub struct DivState {
 698    child_layout_ids: SmallVec<[LayoutId; 2]>,
 699    interactive_state: InteractiveElementState,
 700}
 701
 702impl DivState {
 703    pub fn is_active(&self) -> bool {
 704        self.interactive_state.pending_mouse_down.borrow().is_some()
 705    }
 706}
 707
 708pub struct Interactivity {
 709    pub element_id: Option<ElementId>,
 710    pub key_context: Option<KeyContext>,
 711    pub focusable: bool,
 712    pub tracked_focus_handle: Option<FocusHandle>,
 713    pub scroll_handle: Option<ScrollHandle>,
 714    pub group: Option<SharedString>,
 715    pub base_style: Box<StyleRefinement>,
 716    pub focus_style: Option<Box<StyleRefinement>>,
 717    pub in_focus_style: Option<Box<StyleRefinement>>,
 718    pub hover_style: Option<Box<StyleRefinement>>,
 719    pub group_hover_style: Option<GroupStyle>,
 720    pub active_style: Option<Box<StyleRefinement>>,
 721    pub group_active_style: Option<GroupStyle>,
 722    pub drag_over_styles: Vec<(TypeId, StyleRefinement)>,
 723    pub group_drag_over_styles: Vec<(TypeId, GroupStyle)>,
 724    pub mouse_down_listeners: Vec<MouseDownListener>,
 725    pub mouse_up_listeners: Vec<MouseUpListener>,
 726    pub mouse_move_listeners: Vec<MouseMoveListener>,
 727    pub scroll_wheel_listeners: Vec<ScrollWheelListener>,
 728    pub key_down_listeners: Vec<KeyDownListener>,
 729    pub key_up_listeners: Vec<KeyUpListener>,
 730    pub action_listeners: Vec<(TypeId, ActionListener)>,
 731    pub drop_listeners: Vec<(TypeId, DropListener)>,
 732    pub click_listeners: Vec<ClickListener>,
 733    pub drag_listener: Option<(Box<dyn Any>, DragListener)>,
 734    pub hover_listener: Option<Box<dyn Fn(&bool, &mut WindowContext)>>,
 735    pub tooltip_builder: Option<TooltipBuilder>,
 736
 737    #[cfg(debug_assertions)]
 738    pub location: Option<core::panic::Location<'static>>,
 739}
 740
 741#[derive(Clone, Debug)]
 742pub struct InteractiveBounds {
 743    pub bounds: Bounds<Pixels>,
 744    pub stacking_order: StackingOrder,
 745}
 746
 747impl InteractiveBounds {
 748    pub fn visibly_contains(&self, point: &Point<Pixels>, cx: &WindowContext) -> bool {
 749        self.bounds.contains(point) && cx.was_top_layer(&point, &self.stacking_order)
 750    }
 751
 752    pub fn drag_target_contains(&self, point: &Point<Pixels>, cx: &WindowContext) -> bool {
 753        self.bounds.contains(point)
 754            && cx.was_top_layer_under_active_drag(&point, &self.stacking_order)
 755    }
 756}
 757
 758impl Interactivity {
 759    pub fn layout(
 760        &mut self,
 761        element_state: Option<InteractiveElementState>,
 762        cx: &mut WindowContext,
 763        f: impl FnOnce(Style, &mut WindowContext) -> LayoutId,
 764    ) -> (LayoutId, InteractiveElementState) {
 765        let mut element_state = element_state.unwrap_or_default();
 766
 767        // Ensure we store a focus handle in our element state if we're focusable.
 768        // If there's an explicit focus handle we're tracking, use that. Otherwise
 769        // create a new handle and store it in the element state, which lives for as
 770        // as frames contain an element with this id.
 771        if self.focusable {
 772            element_state.focus_handle.get_or_insert_with(|| {
 773                self.tracked_focus_handle
 774                    .clone()
 775                    .unwrap_or_else(|| cx.focus_handle())
 776            });
 777        }
 778
 779        if let Some(scroll_handle) = self.scroll_handle.as_ref() {
 780            element_state.scroll_offset = Some(scroll_handle.0.borrow().offset.clone());
 781        }
 782
 783        let style = self.compute_style(None, &mut element_state, cx);
 784        let layout_id = f(style, cx);
 785        (layout_id, element_state)
 786    }
 787
 788    pub fn paint(
 789        mut self,
 790        bounds: Bounds<Pixels>,
 791        content_size: Size<Pixels>,
 792        element_state: &mut InteractiveElementState,
 793        cx: &mut WindowContext,
 794        f: impl FnOnce(Style, Point<Pixels>, &mut WindowContext),
 795    ) {
 796        let style = self.compute_style(Some(bounds), element_state, cx);
 797
 798        if style.visibility == Visibility::Hidden {
 799            return;
 800        }
 801
 802        #[cfg(debug_assertions)]
 803        if self.element_id.is_some()
 804            && (style.debug || style.debug_below || cx.has_global::<crate::DebugBelow>())
 805            && bounds.contains(&cx.mouse_position())
 806        {
 807            const FONT_SIZE: crate::Pixels = crate::Pixels(10.);
 808            let element_id = format!("{:?}", self.element_id.unwrap());
 809            let str_len = element_id.len();
 810
 811            let render_debug_text = |cx: &mut WindowContext| {
 812                if let Some(text) = cx
 813                    .text_system()
 814                    .shape_text(
 815                        &element_id,
 816                        FONT_SIZE,
 817                        &[cx.text_style().to_run(str_len)],
 818                        None,
 819                    )
 820                    .ok()
 821                    .map(|mut text| text.pop())
 822                    .flatten()
 823                {
 824                    text.paint(bounds.origin, FONT_SIZE, cx).ok();
 825
 826                    let text_bounds = crate::Bounds {
 827                        origin: bounds.origin,
 828                        size: text.size(FONT_SIZE),
 829                    };
 830                    if self.location.is_some()
 831                        && text_bounds.contains(&cx.mouse_position())
 832                        && cx.modifiers().command
 833                    {
 834                        let command_held = cx.modifiers().command;
 835                        cx.on_key_event({
 836                            let text_bounds = text_bounds.clone();
 837                            move |e: &crate::ModifiersChangedEvent, _phase, cx| {
 838                                if e.modifiers.command != command_held
 839                                    && text_bounds.contains(&cx.mouse_position())
 840                                {
 841                                    cx.notify();
 842                                }
 843                            }
 844                        });
 845
 846                        let hovered = bounds.contains(&cx.mouse_position());
 847                        cx.on_mouse_event(move |event: &MouseMoveEvent, phase, cx| {
 848                            if phase == DispatchPhase::Capture {
 849                                if bounds.contains(&event.position) != hovered {
 850                                    cx.notify();
 851                                }
 852                            }
 853                        });
 854
 855                        cx.on_mouse_event({
 856                            let location = self.location.clone().unwrap();
 857                            let text_bounds = text_bounds.clone();
 858                            move |e: &crate::MouseDownEvent, phase, cx| {
 859                                if text_bounds.contains(&e.position) && phase.capture() {
 860                                    cx.stop_propagation();
 861                                    let Ok(dir) = std::env::current_dir() else {
 862                                        return;
 863                                    };
 864
 865                                    eprintln!(
 866                                        "This element is created at:\n{}:{}:{}",
 867                                        location.file(),
 868                                        location.line(),
 869                                        location.column()
 870                                    );
 871
 872                                    std::process::Command::new("zed")
 873                                        .arg(format!(
 874                                            "{}/{}:{}:{}",
 875                                            dir.to_string_lossy(),
 876                                            location.file(),
 877                                            location.line(),
 878                                            location.column()
 879                                        ))
 880                                        .spawn()
 881                                        .ok();
 882                                }
 883                            }
 884                        });
 885                        cx.paint_quad(crate::outline(
 886                            crate::Bounds {
 887                                origin: bounds.origin
 888                                    + crate::point(crate::px(0.), FONT_SIZE - px(2.)),
 889                                size: crate::Size {
 890                                    width: text_bounds.size.width,
 891                                    height: crate::px(1.),
 892                                },
 893                            },
 894                            crate::red(),
 895                        ))
 896                    }
 897                }
 898            };
 899
 900            cx.with_z_index(1, |cx| {
 901                cx.with_text_style(
 902                    Some(crate::TextStyleRefinement {
 903                        color: Some(crate::red()),
 904                        line_height: Some(FONT_SIZE.into()),
 905                        background_color: Some(crate::white()),
 906                        ..Default::default()
 907                    }),
 908                    render_debug_text,
 909                )
 910            });
 911        }
 912
 913        if style
 914            .background
 915            .as_ref()
 916            .is_some_and(|fill| fill.color().is_some_and(|color| !color.is_transparent()))
 917        {
 918            cx.with_z_index(style.z_index.unwrap_or(0), |cx| cx.add_opaque_layer(bounds))
 919        }
 920
 921        let interactive_bounds = Rc::new(InteractiveBounds {
 922            bounds: bounds.intersect(&cx.content_mask().bounds),
 923            stacking_order: cx.stacking_order().clone(),
 924        });
 925
 926        if let Some(mouse_cursor) = style.mouse_cursor {
 927            let mouse_position = &cx.mouse_position();
 928            let hovered = interactive_bounds.visibly_contains(mouse_position, cx);
 929            if hovered {
 930                cx.set_cursor_style(mouse_cursor);
 931            }
 932        }
 933
 934        // If this element can be focused, register a mouse down listener
 935        // that will automatically transfer focus when hitting the element.
 936        // This behavior can be suppressed by using `cx.prevent_default()`.
 937        if let Some(focus_handle) = element_state.focus_handle.clone() {
 938            cx.on_mouse_event({
 939                let interactive_bounds = interactive_bounds.clone();
 940                move |event: &MouseDownEvent, phase, cx| {
 941                    if phase == DispatchPhase::Bubble
 942                        && !cx.default_prevented()
 943                        && interactive_bounds.visibly_contains(&event.position, cx)
 944                    {
 945                        cx.focus(&focus_handle);
 946                        // If there is a parent that is also focusable, prevent it
 947                        // from trasferring focus because we already did so.
 948                        cx.prevent_default();
 949                    }
 950                }
 951            });
 952        }
 953
 954        for listener in self.mouse_down_listeners.drain(..) {
 955            let interactive_bounds = interactive_bounds.clone();
 956            cx.on_mouse_event(move |event: &MouseDownEvent, phase, cx| {
 957                listener(event, &*interactive_bounds, phase, cx);
 958            })
 959        }
 960
 961        for listener in self.mouse_up_listeners.drain(..) {
 962            let interactive_bounds = interactive_bounds.clone();
 963            cx.on_mouse_event(move |event: &MouseUpEvent, phase, cx| {
 964                listener(event, &*interactive_bounds, phase, cx);
 965            })
 966        }
 967
 968        for listener in self.mouse_move_listeners.drain(..) {
 969            let interactive_bounds = interactive_bounds.clone();
 970            cx.on_mouse_event(move |event: &MouseMoveEvent, phase, cx| {
 971                listener(event, &*interactive_bounds, phase, cx);
 972            })
 973        }
 974
 975        for listener in self.scroll_wheel_listeners.drain(..) {
 976            let interactive_bounds = interactive_bounds.clone();
 977            cx.on_mouse_event(move |event: &ScrollWheelEvent, phase, cx| {
 978                listener(event, &*interactive_bounds, phase, cx);
 979            })
 980        }
 981
 982        let hover_group_bounds = self
 983            .group_hover_style
 984            .as_ref()
 985            .and_then(|group_hover| GroupBounds::get(&group_hover.group, cx));
 986
 987        if let Some(group_bounds) = hover_group_bounds {
 988            let hovered = group_bounds.contains(&cx.mouse_position());
 989            cx.on_mouse_event(move |event: &MouseMoveEvent, phase, cx| {
 990                if phase == DispatchPhase::Capture {
 991                    if group_bounds.contains(&event.position) != hovered {
 992                        cx.notify();
 993                    }
 994                }
 995            });
 996        }
 997
 998        if self.hover_style.is_some()
 999            || self.base_style.mouse_cursor.is_some()
1000            || cx.active_drag.is_some() && !self.drag_over_styles.is_empty()
1001        {
1002            let bounds = bounds.intersect(&cx.content_mask().bounds);
1003            let hovered = bounds.contains(&cx.mouse_position());
1004            cx.on_mouse_event(move |event: &MouseMoveEvent, phase, cx| {
1005                if phase == DispatchPhase::Capture {
1006                    if bounds.contains(&event.position) != hovered {
1007                        cx.notify();
1008                    }
1009                }
1010            });
1011        }
1012
1013        if cx.active_drag.is_some() {
1014            let drop_listeners = mem::take(&mut self.drop_listeners);
1015            let interactive_bounds = interactive_bounds.clone();
1016            if !drop_listeners.is_empty() {
1017                cx.on_mouse_event(move |event: &MouseUpEvent, phase, cx| {
1018                    if phase == DispatchPhase::Bubble
1019                        && interactive_bounds.drag_target_contains(&event.position, cx)
1020                    {
1021                        if let Some(drag_state_type) = cx
1022                            .active_drag
1023                            .as_ref()
1024                            .map(|drag| drag.value.as_ref().type_id())
1025                        {
1026                            for (drop_state_type, listener) in &drop_listeners {
1027                                if *drop_state_type == drag_state_type {
1028                                    let drag = cx
1029                                        .active_drag
1030                                        .take()
1031                                        .expect("checked for type drag state type above");
1032
1033                                    listener(drag.value.as_ref(), cx);
1034                                    cx.notify();
1035                                    cx.stop_propagation();
1036                                }
1037                            }
1038                        } else {
1039                            cx.active_drag = None;
1040                        }
1041                    }
1042                });
1043            }
1044        }
1045
1046        let click_listeners = mem::take(&mut self.click_listeners);
1047        let mut drag_listener = mem::take(&mut self.drag_listener);
1048
1049        if !click_listeners.is_empty() || drag_listener.is_some() {
1050            let pending_mouse_down = element_state.pending_mouse_down.clone();
1051            let mouse_down = pending_mouse_down.borrow().clone();
1052            if let Some(mouse_down) = mouse_down {
1053                if drag_listener.is_some() {
1054                    let active_state = element_state.clicked_state.clone();
1055                    let interactive_bounds = interactive_bounds.clone();
1056
1057                    cx.on_mouse_event(move |event: &MouseMoveEvent, phase, cx| {
1058                        if cx.active_drag.is_some() {
1059                            if phase == DispatchPhase::Capture {
1060                                cx.notify();
1061                            }
1062                        } else if phase == DispatchPhase::Bubble
1063                            && interactive_bounds.visibly_contains(&event.position, cx)
1064                            && (event.position - mouse_down.position).magnitude() > DRAG_THRESHOLD
1065                        {
1066                            let (drag_value, drag_listener) = drag_listener
1067                                .take()
1068                                .expect("The notify below should invalidate this callback");
1069
1070                            *active_state.borrow_mut() = ElementClickedState::default();
1071                            let cursor_offset = event.position - bounds.origin;
1072                            let drag = (drag_listener)(drag_value.as_ref(), cx);
1073                            cx.active_drag = Some(AnyDrag {
1074                                view: drag,
1075                                value: drag_value,
1076                                cursor_offset,
1077                            });
1078                            cx.notify();
1079                            cx.stop_propagation();
1080                        }
1081                    });
1082                }
1083
1084                let interactive_bounds = interactive_bounds.clone();
1085                cx.on_mouse_event(move |event: &MouseUpEvent, phase, cx| {
1086                    if phase == DispatchPhase::Bubble
1087                        && interactive_bounds.visibly_contains(&event.position, cx)
1088                    {
1089                        let mouse_click = ClickEvent {
1090                            down: mouse_down.clone(),
1091                            up: event.clone(),
1092                        };
1093                        for listener in &click_listeners {
1094                            listener(&mouse_click, cx);
1095                        }
1096                    }
1097                    *pending_mouse_down.borrow_mut() = None;
1098                    cx.notify();
1099                });
1100            } else {
1101                let interactive_bounds = interactive_bounds.clone();
1102                cx.on_mouse_event(move |event: &MouseDownEvent, phase, cx| {
1103                    if phase == DispatchPhase::Bubble
1104                        && event.button == MouseButton::Left
1105                        && interactive_bounds.visibly_contains(&event.position, cx)
1106                    {
1107                        *pending_mouse_down.borrow_mut() = Some(event.clone());
1108                        cx.notify();
1109                    }
1110                });
1111            }
1112        }
1113
1114        if let Some(hover_listener) = self.hover_listener.take() {
1115            let was_hovered = element_state.hover_state.clone();
1116            let has_mouse_down = element_state.pending_mouse_down.clone();
1117            let interactive_bounds = interactive_bounds.clone();
1118
1119            cx.on_mouse_event(move |event: &MouseMoveEvent, phase, cx| {
1120                if phase != DispatchPhase::Bubble {
1121                    return;
1122                }
1123                let is_hovered = interactive_bounds.visibly_contains(&event.position, cx)
1124                    && has_mouse_down.borrow().is_none();
1125                let mut was_hovered = was_hovered.borrow_mut();
1126
1127                if is_hovered != was_hovered.clone() {
1128                    *was_hovered = is_hovered;
1129                    drop(was_hovered);
1130
1131                    hover_listener(&is_hovered, cx);
1132                }
1133            });
1134        }
1135
1136        if let Some(tooltip_builder) = self.tooltip_builder.take() {
1137            let active_tooltip = element_state.active_tooltip.clone();
1138            let pending_mouse_down = element_state.pending_mouse_down.clone();
1139            let interactive_bounds = interactive_bounds.clone();
1140
1141            cx.on_mouse_event(move |event: &MouseMoveEvent, phase, cx| {
1142                let is_hovered = interactive_bounds.visibly_contains(&event.position, cx)
1143                    && pending_mouse_down.borrow().is_none();
1144                if !is_hovered {
1145                    active_tooltip.borrow_mut().take();
1146                    return;
1147                }
1148
1149                if phase != DispatchPhase::Bubble {
1150                    return;
1151                }
1152
1153                if active_tooltip.borrow().is_none() {
1154                    let task = cx.spawn({
1155                        let active_tooltip = active_tooltip.clone();
1156                        let tooltip_builder = tooltip_builder.clone();
1157
1158                        move |mut cx| async move {
1159                            cx.background_executor().timer(TOOLTIP_DELAY).await;
1160                            cx.update(|_, cx| {
1161                                active_tooltip.borrow_mut().replace(ActiveTooltip {
1162                                    tooltip: Some(AnyTooltip {
1163                                        view: tooltip_builder(cx),
1164                                        cursor_offset: cx.mouse_position(),
1165                                    }),
1166                                    _task: None,
1167                                });
1168                                cx.notify();
1169                            })
1170                            .ok();
1171                        }
1172                    });
1173                    active_tooltip.borrow_mut().replace(ActiveTooltip {
1174                        tooltip: None,
1175                        _task: Some(task),
1176                    });
1177                }
1178            });
1179
1180            let active_tooltip = element_state.active_tooltip.clone();
1181            cx.on_mouse_event(move |_: &MouseDownEvent, _, _| {
1182                active_tooltip.borrow_mut().take();
1183            });
1184
1185            if let Some(active_tooltip) = element_state.active_tooltip.borrow().as_ref() {
1186                if active_tooltip.tooltip.is_some() {
1187                    cx.active_tooltip = active_tooltip.tooltip.clone()
1188                }
1189            }
1190        }
1191
1192        let active_state = element_state.clicked_state.clone();
1193        if active_state.borrow().is_clicked() {
1194            cx.on_mouse_event(move |_: &MouseUpEvent, phase, cx| {
1195                if phase == DispatchPhase::Capture {
1196                    *active_state.borrow_mut() = ElementClickedState::default();
1197                    cx.notify();
1198                }
1199            });
1200        } else {
1201            let active_group_bounds = self
1202                .group_active_style
1203                .as_ref()
1204                .and_then(|group_active| GroupBounds::get(&group_active.group, cx));
1205            let interactive_bounds = interactive_bounds.clone();
1206            cx.on_mouse_event(move |down: &MouseDownEvent, phase, cx| {
1207                if phase == DispatchPhase::Bubble && !cx.default_prevented() {
1208                    let group =
1209                        active_group_bounds.map_or(false, |bounds| bounds.contains(&down.position));
1210                    let element = interactive_bounds.visibly_contains(&down.position, cx);
1211                    if group || element {
1212                        *active_state.borrow_mut() = ElementClickedState { group, element };
1213                        cx.notify();
1214                    }
1215                }
1216            });
1217        }
1218
1219        let overflow = style.overflow;
1220        if overflow.x == Overflow::Scroll || overflow.y == Overflow::Scroll {
1221            if let Some(scroll_handle) = &self.scroll_handle {
1222                scroll_handle.0.borrow_mut().overflow = overflow;
1223            }
1224
1225            let scroll_offset = element_state
1226                .scroll_offset
1227                .get_or_insert_with(Rc::default)
1228                .clone();
1229            let line_height = cx.line_height();
1230            let scroll_max = (content_size - bounds.size).max(&Size::default());
1231            let interactive_bounds = interactive_bounds.clone();
1232
1233            cx.on_mouse_event(move |event: &ScrollWheelEvent, phase, cx| {
1234                if phase == DispatchPhase::Bubble
1235                    && interactive_bounds.visibly_contains(&event.position, cx)
1236                {
1237                    let mut scroll_offset = scroll_offset.borrow_mut();
1238                    let old_scroll_offset = *scroll_offset;
1239                    let delta = event.delta.pixel_delta(line_height);
1240
1241                    if overflow.x == Overflow::Scroll {
1242                        scroll_offset.x =
1243                            (scroll_offset.x + delta.x).clamp(-scroll_max.width, px(0.));
1244                    }
1245
1246                    if overflow.y == Overflow::Scroll {
1247                        scroll_offset.y =
1248                            (scroll_offset.y + delta.y).clamp(-scroll_max.height, px(0.));
1249                    }
1250
1251                    if *scroll_offset != old_scroll_offset {
1252                        cx.notify();
1253                        cx.stop_propagation();
1254                    }
1255                }
1256            });
1257        }
1258
1259        if let Some(group) = self.group.clone() {
1260            GroupBounds::push(group, bounds, cx);
1261        }
1262
1263        let scroll_offset = element_state
1264            .scroll_offset
1265            .as_ref()
1266            .map(|scroll_offset| *scroll_offset.borrow());
1267
1268        cx.with_key_dispatch(
1269            self.key_context.clone(),
1270            element_state.focus_handle.clone(),
1271            |_, cx| {
1272                for listener in self.key_down_listeners.drain(..) {
1273                    cx.on_key_event(move |event: &KeyDownEvent, phase, cx| {
1274                        listener(event, phase, cx);
1275                    })
1276                }
1277
1278                for listener in self.key_up_listeners.drain(..) {
1279                    cx.on_key_event(move |event: &KeyUpEvent, phase, cx| {
1280                        listener(event, phase, cx);
1281                    })
1282                }
1283
1284                for (action_type, listener) in self.action_listeners {
1285                    cx.on_action(action_type, listener)
1286                }
1287
1288                f(style, scroll_offset.unwrap_or_default(), cx)
1289            },
1290        );
1291
1292        if let Some(group) = self.group.as_ref() {
1293            GroupBounds::pop(group, cx);
1294        }
1295    }
1296
1297    pub fn compute_style(
1298        &self,
1299        bounds: Option<Bounds<Pixels>>,
1300        element_state: &mut InteractiveElementState,
1301        cx: &mut WindowContext,
1302    ) -> Style {
1303        let mut style = Style::default();
1304        style.refine(&self.base_style);
1305
1306        cx.with_z_index(style.z_index.unwrap_or(0), |cx| {
1307            if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
1308                if let Some(in_focus_style) = self.in_focus_style.as_ref() {
1309                    if focus_handle.within_focused(cx) {
1310                        style.refine(in_focus_style);
1311                    }
1312                }
1313
1314                if let Some(focus_style) = self.focus_style.as_ref() {
1315                    if focus_handle.is_focused(cx) {
1316                        style.refine(focus_style);
1317                    }
1318                }
1319            }
1320
1321            if let Some(bounds) = bounds {
1322                let mouse_position = cx.mouse_position();
1323                if let Some(group_hover) = self.group_hover_style.as_ref() {
1324                    if let Some(group_bounds) = GroupBounds::get(&group_hover.group, cx) {
1325                        if group_bounds.contains(&mouse_position)
1326                            && cx.was_top_layer(&mouse_position, cx.stacking_order())
1327                        {
1328                            style.refine(&group_hover.style);
1329                        }
1330                    }
1331                }
1332                if let Some(hover_style) = self.hover_style.as_ref() {
1333                    if bounds
1334                        .intersect(&cx.content_mask().bounds)
1335                        .contains(&mouse_position)
1336                        && cx.was_top_layer(&mouse_position, cx.stacking_order())
1337                    {
1338                        style.refine(hover_style);
1339                    }
1340                }
1341
1342                if let Some(drag) = cx.active_drag.take() {
1343                    for (state_type, group_drag_style) in &self.group_drag_over_styles {
1344                        if let Some(group_bounds) = GroupBounds::get(&group_drag_style.group, cx) {
1345                            if *state_type == drag.value.as_ref().type_id()
1346                                && group_bounds.contains(&mouse_position)
1347                            {
1348                                style.refine(&group_drag_style.style);
1349                            }
1350                        }
1351                    }
1352
1353                    for (state_type, drag_over_style) in &self.drag_over_styles {
1354                        if *state_type == drag.value.as_ref().type_id()
1355                            && bounds
1356                                .intersect(&cx.content_mask().bounds)
1357                                .contains(&mouse_position)
1358                            && cx.was_top_layer_under_active_drag(
1359                                &mouse_position,
1360                                cx.stacking_order(),
1361                            )
1362                        {
1363                            style.refine(drag_over_style);
1364                        }
1365                    }
1366
1367                    cx.active_drag = Some(drag);
1368                }
1369            }
1370
1371            let clicked_state = element_state.clicked_state.borrow();
1372            if clicked_state.group {
1373                if let Some(group) = self.group_active_style.as_ref() {
1374                    style.refine(&group.style)
1375                }
1376            }
1377
1378            if let Some(active_style) = self.active_style.as_ref() {
1379                if clicked_state.element {
1380                    style.refine(active_style)
1381                }
1382            }
1383        });
1384
1385        style
1386    }
1387}
1388
1389impl Default for Interactivity {
1390    fn default() -> Self {
1391        Self {
1392            element_id: None,
1393            key_context: None,
1394            focusable: false,
1395            tracked_focus_handle: None,
1396            scroll_handle: None,
1397            // scroll_offset: Point::default(),
1398            group: None,
1399            base_style: Box::new(StyleRefinement::default()),
1400            focus_style: None,
1401            in_focus_style: None,
1402            hover_style: None,
1403            group_hover_style: None,
1404            active_style: None,
1405            group_active_style: None,
1406            drag_over_styles: Vec::new(),
1407            group_drag_over_styles: Vec::new(),
1408            mouse_down_listeners: Vec::new(),
1409            mouse_up_listeners: Vec::new(),
1410            mouse_move_listeners: Vec::new(),
1411            scroll_wheel_listeners: Vec::new(),
1412            key_down_listeners: Vec::new(),
1413            key_up_listeners: Vec::new(),
1414            action_listeners: Vec::new(),
1415            drop_listeners: Vec::new(),
1416            click_listeners: Vec::new(),
1417            drag_listener: None,
1418            hover_listener: None,
1419            tooltip_builder: None,
1420
1421            #[cfg(debug_assertions)]
1422            location: None,
1423        }
1424    }
1425}
1426
1427#[derive(Default)]
1428pub struct InteractiveElementState {
1429    pub focus_handle: Option<FocusHandle>,
1430    pub clicked_state: Rc<RefCell<ElementClickedState>>,
1431    pub hover_state: Rc<RefCell<bool>>,
1432    pub pending_mouse_down: Rc<RefCell<Option<MouseDownEvent>>>,
1433    pub scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
1434    pub active_tooltip: Rc<RefCell<Option<ActiveTooltip>>>,
1435}
1436
1437pub struct ActiveTooltip {
1438    tooltip: Option<AnyTooltip>,
1439    _task: Option<Task<()>>,
1440}
1441
1442/// Whether or not the element or a group that contains it is clicked by the mouse.
1443#[derive(Copy, Clone, Default, Eq, PartialEq)]
1444pub struct ElementClickedState {
1445    pub group: bool,
1446    pub element: bool,
1447}
1448
1449impl ElementClickedState {
1450    fn is_clicked(&self) -> bool {
1451        self.group || self.element
1452    }
1453}
1454
1455#[derive(Default)]
1456pub struct GroupBounds(HashMap<SharedString, SmallVec<[Bounds<Pixels>; 1]>>);
1457
1458impl GroupBounds {
1459    pub fn get(name: &SharedString, cx: &mut AppContext) -> Option<Bounds<Pixels>> {
1460        cx.default_global::<Self>()
1461            .0
1462            .get(name)
1463            .and_then(|bounds_stack| bounds_stack.last())
1464            .cloned()
1465    }
1466
1467    pub fn push(name: SharedString, bounds: Bounds<Pixels>, cx: &mut AppContext) {
1468        cx.default_global::<Self>()
1469            .0
1470            .entry(name)
1471            .or_default()
1472            .push(bounds);
1473    }
1474
1475    pub fn pop(name: &SharedString, cx: &mut AppContext) {
1476        cx.default_global::<Self>().0.get_mut(name).unwrap().pop();
1477    }
1478}
1479
1480pub struct Focusable<E> {
1481    pub element: E,
1482}
1483
1484impl<E: InteractiveElement> FocusableElement for Focusable<E> {}
1485
1486impl<E> InteractiveElement for Focusable<E>
1487where
1488    E: InteractiveElement,
1489{
1490    fn interactivity(&mut self) -> &mut Interactivity {
1491        self.element.interactivity()
1492    }
1493}
1494
1495impl<E: StatefulInteractiveElement> StatefulInteractiveElement for Focusable<E> {}
1496
1497impl<E> Styled for Focusable<E>
1498where
1499    E: Styled,
1500{
1501    fn style(&mut self) -> &mut StyleRefinement {
1502        self.element.style()
1503    }
1504}
1505
1506impl<E> Element for Focusable<E>
1507where
1508    E: Element,
1509{
1510    type State = E::State;
1511
1512    fn layout(
1513        &mut self,
1514        state: Option<Self::State>,
1515        cx: &mut WindowContext,
1516    ) -> (LayoutId, Self::State) {
1517        self.element.layout(state, cx)
1518    }
1519
1520    fn paint(self, bounds: Bounds<Pixels>, state: &mut Self::State, cx: &mut WindowContext) {
1521        self.element.paint(bounds, state, cx)
1522    }
1523}
1524
1525impl<E> IntoElement for Focusable<E>
1526where
1527    E: IntoElement,
1528{
1529    type Element = E::Element;
1530
1531    fn element_id(&self) -> Option<ElementId> {
1532        self.element.element_id()
1533    }
1534
1535    fn into_element(self) -> Self::Element {
1536        self.element.into_element()
1537    }
1538}
1539
1540impl<E> ParentElement for Focusable<E>
1541where
1542    E: ParentElement,
1543{
1544    fn children_mut(&mut self) -> &mut SmallVec<[AnyElement; 2]> {
1545        self.element.children_mut()
1546    }
1547}
1548
1549pub struct Stateful<E> {
1550    element: E,
1551}
1552
1553impl<E> Styled for Stateful<E>
1554where
1555    E: Styled,
1556{
1557    fn style(&mut self) -> &mut StyleRefinement {
1558        self.element.style()
1559    }
1560}
1561
1562impl<E> StatefulInteractiveElement for Stateful<E>
1563where
1564    E: Element,
1565    Self: InteractiveElement,
1566{
1567}
1568
1569impl<E> InteractiveElement for Stateful<E>
1570where
1571    E: InteractiveElement,
1572{
1573    fn interactivity(&mut self) -> &mut Interactivity {
1574        self.element.interactivity()
1575    }
1576}
1577
1578impl<E: FocusableElement> FocusableElement for Stateful<E> {}
1579
1580impl<E> Element for Stateful<E>
1581where
1582    E: Element,
1583{
1584    type State = E::State;
1585
1586    fn layout(
1587        &mut self,
1588        state: Option<Self::State>,
1589        cx: &mut WindowContext,
1590    ) -> (LayoutId, Self::State) {
1591        self.element.layout(state, cx)
1592    }
1593
1594    fn paint(self, bounds: Bounds<Pixels>, state: &mut Self::State, cx: &mut WindowContext) {
1595        self.element.paint(bounds, state, cx)
1596    }
1597}
1598
1599impl<E> IntoElement for Stateful<E>
1600where
1601    E: Element,
1602{
1603    type Element = Self;
1604
1605    fn element_id(&self) -> Option<ElementId> {
1606        self.element.element_id()
1607    }
1608
1609    fn into_element(self) -> Self::Element {
1610        self
1611    }
1612}
1613
1614impl<E> ParentElement for Stateful<E>
1615where
1616    E: ParentElement,
1617{
1618    fn children_mut(&mut self) -> &mut SmallVec<[AnyElement; 2]> {
1619        self.element.children_mut()
1620    }
1621}
1622
1623#[derive(Default)]
1624struct ScrollHandleState {
1625    // not great to have the nested rc's...
1626    offset: Rc<RefCell<Point<Pixels>>>,
1627    bounds: Bounds<Pixels>,
1628    child_bounds: Vec<Bounds<Pixels>>,
1629    requested_scroll_top: Option<(usize, Pixels)>,
1630    overflow: Point<Overflow>,
1631}
1632
1633#[derive(Clone)]
1634pub struct ScrollHandle(Rc<RefCell<ScrollHandleState>>);
1635
1636impl ScrollHandle {
1637    pub fn new() -> Self {
1638        Self(Rc::default())
1639    }
1640
1641    pub fn offset(&self) -> Point<Pixels> {
1642        self.0.borrow().offset.borrow().clone()
1643    }
1644
1645    pub fn top_item(&self) -> usize {
1646        let state = self.0.borrow();
1647        let top = state.bounds.top() - state.offset.borrow().y;
1648
1649        match state.child_bounds.binary_search_by(|bounds| {
1650            if top < bounds.top() {
1651                Ordering::Greater
1652            } else if top > bounds.bottom() {
1653                Ordering::Less
1654            } else {
1655                Ordering::Equal
1656            }
1657        }) {
1658            Ok(ix) => ix,
1659            Err(ix) => ix.min(state.child_bounds.len().saturating_sub(1)),
1660        }
1661    }
1662
1663    pub fn bounds_for_item(&self, ix: usize) -> Option<Bounds<Pixels>> {
1664        self.0.borrow().child_bounds.get(ix).cloned()
1665    }
1666
1667    /// scroll_to_item scrolls the minimal amount to ensure that the item is
1668    /// fully visible
1669    pub fn scroll_to_item(&self, ix: usize) {
1670        let state = self.0.borrow();
1671
1672        let Some(bounds) = state.child_bounds.get(ix) else {
1673            return;
1674        };
1675
1676        let mut scroll_offset = state.offset.borrow_mut();
1677
1678        if state.overflow.y == Overflow::Scroll {
1679            if bounds.top() + scroll_offset.y < state.bounds.top() {
1680                scroll_offset.y = state.bounds.top() - bounds.top();
1681            } else if bounds.bottom() + scroll_offset.y > state.bounds.bottom() {
1682                scroll_offset.y = state.bounds.bottom() - bounds.bottom();
1683            }
1684        }
1685
1686        if state.overflow.x == Overflow::Scroll {
1687            if bounds.left() + scroll_offset.x < state.bounds.left() {
1688                scroll_offset.x = state.bounds.left() - bounds.left();
1689            } else if bounds.right() + scroll_offset.x > state.bounds.right() {
1690                scroll_offset.x = state.bounds.right() - bounds.right();
1691            }
1692        }
1693    }
1694
1695    pub fn logical_scroll_top(&self) -> (usize, Pixels) {
1696        let ix = self.top_item();
1697        let state = self.0.borrow();
1698
1699        if let Some(child_bounds) = state.child_bounds.get(ix) {
1700            (
1701                ix,
1702                child_bounds.top() + state.offset.borrow().y - state.bounds.top(),
1703            )
1704        } else {
1705            (ix, px(0.))
1706        }
1707    }
1708
1709    pub fn set_logical_scroll_top(&self, ix: usize, px: Pixels) {
1710        self.0.borrow_mut().requested_scroll_top = Some((ix, px));
1711    }
1712}