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