div.rs

   1//! Div is the central, reusable element that most GPUI trees will be built from.
   2//! It functions as a container for other elements, and provides a number of
   3//! useful features for laying out and styling its children as well as binding
   4//! mouse events and action handlers. It is meant to be similar to the HTML `<div>`
   5//! element, but for GPUI.
   6//!
   7//! # Build your own div
   8//!
   9//! GPUI does not directly provide APIs for stateful, multi step events like `click`
  10//! and `drag`. We want GPUI users to be able to build their own abstractions for
  11//! their own needs. However, as a UI framework, we're also obliged to provide some
  12//! building blocks to make the process of building your own elements easier.
  13//! For this we have the [`Interactivity`] and the [`StyleRefinement`] structs, as well
  14//! as several associated traits. Together, these provide the full suite of Dom-like events
  15//! and Tailwind-like styling that you can use to build your own custom elements. Div is
  16//! constructed by combining these two systems into an all-in-one element.
  17
  18use crate::{
  19    Action, AnyDrag, AnyElement, AnyTooltip, AnyView, App, Bounds, ClickEvent, DispatchPhase,
  20    Element, ElementId, Entity, FocusHandle, Global, GlobalElementId, Hitbox, HitboxBehavior,
  21    HitboxId, InspectorElementId, IntoElement, IsZero, KeyContext, KeyDownEvent, KeyUpEvent,
  22    LayoutId, ModifiersChangedEvent, MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent,
  23    Overflow, ParentElement, Pixels, Point, Render, ScrollWheelEvent, SharedString, Size, Style,
  24    StyleRefinement, Styled, Task, TooltipId, Visibility, Window, WindowControlArea, point, px,
  25    size,
  26};
  27use collections::HashMap;
  28use refineable::Refineable;
  29use smallvec::SmallVec;
  30use std::{
  31    any::{Any, TypeId},
  32    cell::RefCell,
  33    cmp::Ordering,
  34    fmt::Debug,
  35    marker::PhantomData,
  36    mem,
  37    rc::Rc,
  38    sync::Arc,
  39    time::Duration,
  40};
  41use util::ResultExt;
  42
  43use super::ImageCacheProvider;
  44
  45const DRAG_THRESHOLD: f64 = 2.;
  46const TOOLTIP_SHOW_DELAY: Duration = Duration::from_millis(500);
  47const HOVERABLE_TOOLTIP_HIDE_DELAY: Duration = Duration::from_millis(500);
  48
  49/// The styling information for a given group.
  50pub struct GroupStyle {
  51    /// The identifier for this group.
  52    pub group: SharedString,
  53
  54    /// The specific style refinement that this group would apply
  55    /// to its children.
  56    pub style: Box<StyleRefinement>,
  57}
  58
  59/// An event for when a drag is moving over this element, with the given state type.
  60pub struct DragMoveEvent<T> {
  61    /// The mouse move event that triggered this drag move event.
  62    pub event: MouseMoveEvent,
  63
  64    /// The bounds of this element.
  65    pub bounds: Bounds<Pixels>,
  66    drag: PhantomData<T>,
  67    dragged_item: Arc<dyn Any>,
  68}
  69
  70impl<T: 'static> DragMoveEvent<T> {
  71    /// Returns the drag state for this event.
  72    pub fn drag<'b>(&self, cx: &'b App) -> &'b T {
  73        cx.active_drag
  74            .as_ref()
  75            .and_then(|drag| drag.value.downcast_ref::<T>())
  76            .expect("DragMoveEvent is only valid when the stored active drag is of the same type.")
  77    }
  78
  79    /// An item that is about to be dropped.
  80    pub fn dragged_item(&self) -> &dyn Any {
  81        self.dragged_item.as_ref()
  82    }
  83}
  84
  85impl Interactivity {
  86    /// Create an `Interactivity`, capturing the caller location in debug mode.
  87    #[cfg(any(feature = "inspector", debug_assertions))]
  88    #[track_caller]
  89    pub fn new() -> Interactivity {
  90        Interactivity {
  91            source_location: Some(core::panic::Location::caller()),
  92            ..Default::default()
  93        }
  94    }
  95
  96    /// Create an `Interactivity`, capturing the caller location in debug mode.
  97    #[cfg(not(any(feature = "inspector", debug_assertions)))]
  98    pub fn new() -> Interactivity {
  99        Interactivity::default()
 100    }
 101
 102    /// Gets the source location of construction. Returns `None` when not in debug mode.
 103    pub fn source_location(&self) -> Option<&'static std::panic::Location<'static>> {
 104        #[cfg(any(feature = "inspector", debug_assertions))]
 105        {
 106            self.source_location
 107        }
 108
 109        #[cfg(not(any(feature = "inspector", debug_assertions)))]
 110        {
 111            None
 112        }
 113    }
 114
 115    /// Bind the given callback to the mouse down event for the given mouse button, during the bubble phase
 116    /// The imperative API equivalent of [`InteractiveElement::on_mouse_down`]
 117    ///
 118    /// See [`Context::listener`](crate::Context::listener) to get access to the view state from this callback.
 119    pub fn on_mouse_down(
 120        &mut self,
 121        button: MouseButton,
 122        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 123    ) {
 124        self.mouse_down_listeners
 125            .push(Box::new(move |event, phase, hitbox, window, cx| {
 126                if phase == DispatchPhase::Bubble
 127                    && event.button == button
 128                    && hitbox.is_hovered(window)
 129                {
 130                    (listener)(event, window, cx)
 131                }
 132            }));
 133    }
 134
 135    /// Bind the given callback to the mouse down event for any button, during the capture phase
 136    /// The imperative API equivalent of [`InteractiveElement::capture_any_mouse_down`]
 137    ///
 138    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 139    pub fn capture_any_mouse_down(
 140        &mut self,
 141        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 142    ) {
 143        self.mouse_down_listeners
 144            .push(Box::new(move |event, phase, hitbox, window, cx| {
 145                if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 146                    (listener)(event, window, cx)
 147                }
 148            }));
 149    }
 150
 151    /// Bind the given callback to the mouse down event for any button, during the bubble phase
 152    /// the imperative API equivalent to [`InteractiveElement::on_any_mouse_down`]
 153    ///
 154    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 155    pub fn on_any_mouse_down(
 156        &mut self,
 157        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 158    ) {
 159        self.mouse_down_listeners
 160            .push(Box::new(move |event, phase, hitbox, window, cx| {
 161                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
 162                    (listener)(event, window, cx)
 163                }
 164            }));
 165    }
 166
 167    /// Bind the given callback to the mouse up event for the given button, during the bubble phase
 168    /// the imperative API equivalent to [`InteractiveElement::on_mouse_up`]
 169    ///
 170    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 171    pub fn on_mouse_up(
 172        &mut self,
 173        button: MouseButton,
 174        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 175    ) {
 176        self.mouse_up_listeners
 177            .push(Box::new(move |event, phase, hitbox, window, cx| {
 178                if phase == DispatchPhase::Bubble
 179                    && event.button == button
 180                    && hitbox.is_hovered(window)
 181                {
 182                    (listener)(event, window, cx)
 183                }
 184            }));
 185    }
 186
 187    /// Bind the given callback to the mouse up event for any button, during the capture phase
 188    /// the imperative API equivalent to [`InteractiveElement::capture_any_mouse_up`]
 189    ///
 190    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 191    pub fn capture_any_mouse_up(
 192        &mut self,
 193        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 194    ) {
 195        self.mouse_up_listeners
 196            .push(Box::new(move |event, phase, hitbox, window, cx| {
 197                if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 198                    (listener)(event, window, cx)
 199                }
 200            }));
 201    }
 202
 203    /// Bind the given callback to the mouse up event for any button, during the bubble phase
 204    /// the imperative API equivalent to [`Interactivity::on_any_mouse_up`]
 205    ///
 206    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 207    pub fn on_any_mouse_up(
 208        &mut self,
 209        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 210    ) {
 211        self.mouse_up_listeners
 212            .push(Box::new(move |event, phase, hitbox, window, cx| {
 213                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
 214                    (listener)(event, window, cx)
 215                }
 216            }));
 217    }
 218
 219    /// Bind the given callback to the mouse down event, on any button, during the capture phase,
 220    /// when the mouse is outside of the bounds of this element.
 221    /// The imperative API equivalent to [`InteractiveElement::on_mouse_down_out`]
 222    ///
 223    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 224    pub fn on_mouse_down_out(
 225        &mut self,
 226        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 227    ) {
 228        self.mouse_down_listeners
 229            .push(Box::new(move |event, phase, hitbox, window, cx| {
 230                if phase == DispatchPhase::Capture && !hitbox.contains(&window.mouse_position()) {
 231                    (listener)(event, window, cx)
 232                }
 233            }));
 234    }
 235
 236    /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
 237    /// when the mouse is outside of the bounds of this element.
 238    /// The imperative API equivalent to [`InteractiveElement::on_mouse_up_out`]
 239    ///
 240    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 241    pub fn on_mouse_up_out(
 242        &mut self,
 243        button: MouseButton,
 244        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 245    ) {
 246        self.mouse_up_listeners
 247            .push(Box::new(move |event, phase, hitbox, window, cx| {
 248                if phase == DispatchPhase::Capture
 249                    && event.button == button
 250                    && !hitbox.is_hovered(window)
 251                {
 252                    (listener)(event, window, cx);
 253                }
 254            }));
 255    }
 256
 257    /// Bind the given callback to the mouse move event, during the bubble phase
 258    /// The imperative API equivalent to [`InteractiveElement::on_mouse_move`]
 259    ///
 260    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 261    pub fn on_mouse_move(
 262        &mut self,
 263        listener: impl Fn(&MouseMoveEvent, &mut Window, &mut App) + 'static,
 264    ) {
 265        self.mouse_move_listeners
 266            .push(Box::new(move |event, phase, hitbox, window, cx| {
 267                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
 268                    (listener)(event, window, cx);
 269                }
 270            }));
 271    }
 272
 273    /// Bind the given callback to the mouse drag event of the given type. Note that this
 274    /// will be called for all move events, inside or outside of this element, as long as the
 275    /// drag was started with this element under the mouse. Useful for implementing draggable
 276    /// UIs that don't conform to a drag and drop style interaction, like resizing.
 277    /// The imperative API equivalent to [`InteractiveElement::on_drag_move`]
 278    ///
 279    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 280    pub fn on_drag_move<T>(
 281        &mut self,
 282        listener: impl Fn(&DragMoveEvent<T>, &mut Window, &mut App) + 'static,
 283    ) where
 284        T: 'static,
 285    {
 286        self.mouse_move_listeners
 287            .push(Box::new(move |event, phase, hitbox, window, cx| {
 288                if phase == DispatchPhase::Capture {
 289                    if let Some(drag) = &cx.active_drag {
 290                        if drag.value.as_ref().type_id() == TypeId::of::<T>() {
 291                            (listener)(
 292                                &DragMoveEvent {
 293                                    event: event.clone(),
 294                                    bounds: hitbox.bounds,
 295                                    drag: PhantomData,
 296                                    dragged_item: Arc::clone(&drag.value),
 297                                },
 298                                window,
 299                                cx,
 300                            );
 301                        }
 302                    }
 303                }
 304            }));
 305    }
 306
 307    /// Bind the given callback to scroll wheel events during the bubble phase
 308    /// The imperative API equivalent to [`InteractiveElement::on_scroll_wheel`]
 309    ///
 310    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 311    pub fn on_scroll_wheel(
 312        &mut self,
 313        listener: impl Fn(&ScrollWheelEvent, &mut Window, &mut App) + 'static,
 314    ) {
 315        self.scroll_wheel_listeners
 316            .push(Box::new(move |event, phase, hitbox, window, cx| {
 317                if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
 318                    (listener)(event, window, cx);
 319                }
 320            }));
 321    }
 322
 323    /// Bind the given callback to an action dispatch during the capture phase
 324    /// The imperative API equivalent to [`InteractiveElement::capture_action`]
 325    ///
 326    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 327    pub fn capture_action<A: Action>(
 328        &mut self,
 329        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
 330    ) {
 331        self.action_listeners.push((
 332            TypeId::of::<A>(),
 333            Box::new(move |action, phase, window, cx| {
 334                let action = action.downcast_ref().unwrap();
 335                if phase == DispatchPhase::Capture {
 336                    (listener)(action, window, cx)
 337                } else {
 338                    cx.propagate();
 339                }
 340            }),
 341        ));
 342    }
 343
 344    /// Bind the given callback to an action dispatch during the bubble phase
 345    /// The imperative API equivalent to [`InteractiveElement::on_action`]
 346    ///
 347    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 348    pub fn on_action<A: Action>(&mut self, listener: impl Fn(&A, &mut Window, &mut App) + 'static) {
 349        self.action_listeners.push((
 350            TypeId::of::<A>(),
 351            Box::new(move |action, phase, window, cx| {
 352                let action = action.downcast_ref().unwrap();
 353                if phase == DispatchPhase::Bubble {
 354                    (listener)(action, window, cx)
 355                }
 356            }),
 357        ));
 358    }
 359
 360    /// Bind the given callback to an action dispatch, based on a dynamic action parameter
 361    /// instead of a type parameter. Useful for component libraries that want to expose
 362    /// action bindings to their users.
 363    /// The imperative API equivalent to [`InteractiveElement::on_boxed_action`]
 364    ///
 365    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 366    pub fn on_boxed_action(
 367        &mut self,
 368        action: &dyn Action,
 369        listener: impl Fn(&dyn Action, &mut Window, &mut App) + 'static,
 370    ) {
 371        let action = action.boxed_clone();
 372        self.action_listeners.push((
 373            (*action).type_id(),
 374            Box::new(move |_, phase, window, cx| {
 375                if phase == DispatchPhase::Bubble {
 376                    (listener)(&*action, window, cx)
 377                }
 378            }),
 379        ));
 380    }
 381
 382    /// Bind the given callback to key down events during the bubble phase
 383    /// The imperative API equivalent to [`InteractiveElement::on_key_down`]
 384    ///
 385    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 386    pub fn on_key_down(
 387        &mut self,
 388        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
 389    ) {
 390        self.key_down_listeners
 391            .push(Box::new(move |event, phase, window, cx| {
 392                if phase == DispatchPhase::Bubble {
 393                    (listener)(event, window, cx)
 394                }
 395            }));
 396    }
 397
 398    /// Bind the given callback to key down events during the capture phase
 399    /// The imperative API equivalent to [`InteractiveElement::capture_key_down`]
 400    ///
 401    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 402    pub fn capture_key_down(
 403        &mut self,
 404        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
 405    ) {
 406        self.key_down_listeners
 407            .push(Box::new(move |event, phase, window, cx| {
 408                if phase == DispatchPhase::Capture {
 409                    listener(event, window, cx)
 410                }
 411            }));
 412    }
 413
 414    /// Bind the given callback to key up events during the bubble phase
 415    /// The imperative API equivalent to [`InteractiveElement::on_key_up`]
 416    ///
 417    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 418    pub fn on_key_up(&mut self, listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static) {
 419        self.key_up_listeners
 420            .push(Box::new(move |event, phase, window, cx| {
 421                if phase == DispatchPhase::Bubble {
 422                    listener(event, window, cx)
 423                }
 424            }));
 425    }
 426
 427    /// Bind the given callback to key up events during the capture phase
 428    /// The imperative API equivalent to [`InteractiveElement::on_key_up`]
 429    ///
 430    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 431    pub fn capture_key_up(
 432        &mut self,
 433        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
 434    ) {
 435        self.key_up_listeners
 436            .push(Box::new(move |event, phase, window, cx| {
 437                if phase == DispatchPhase::Capture {
 438                    listener(event, window, cx)
 439                }
 440            }));
 441    }
 442
 443    /// Bind the given callback to modifiers changing events.
 444    /// The imperative API equivalent to [`InteractiveElement::on_modifiers_changed`]
 445    ///
 446    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 447    pub fn on_modifiers_changed(
 448        &mut self,
 449        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
 450    ) {
 451        self.modifiers_changed_listeners
 452            .push(Box::new(move |event, window, cx| {
 453                listener(event, window, cx)
 454            }));
 455    }
 456
 457    /// Bind the given callback to drop events of the given type, whether or not the drag started on this element
 458    /// The imperative API equivalent to [`InteractiveElement::on_drop`]
 459    ///
 460    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 461    pub fn on_drop<T: 'static>(&mut self, listener: impl Fn(&T, &mut Window, &mut App) + 'static) {
 462        self.drop_listeners.push((
 463            TypeId::of::<T>(),
 464            Box::new(move |dragged_value, window, cx| {
 465                listener(dragged_value.downcast_ref().unwrap(), window, cx);
 466            }),
 467        ));
 468    }
 469
 470    /// Use the given predicate to determine whether or not a drop event should be dispatched to this element
 471    /// The imperative API equivalent to [`InteractiveElement::can_drop`]
 472    pub fn can_drop(
 473        &mut self,
 474        predicate: impl Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static,
 475    ) {
 476        self.can_drop_predicate = Some(Box::new(predicate));
 477    }
 478
 479    /// Bind the given callback to click events of this element
 480    /// The imperative API equivalent to [`StatefulInteractiveElement::on_click`]
 481    ///
 482    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 483    pub fn on_click(&mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static)
 484    where
 485        Self: Sized,
 486    {
 487        self.click_listeners
 488            .push(Box::new(move |event, window, cx| {
 489                listener(event, window, cx)
 490            }));
 491    }
 492
 493    /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
 494    /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
 495    /// the [`Self::on_drag_move`] API
 496    /// The imperative API equivalent to [`StatefulInteractiveElement::on_drag`]
 497    ///
 498    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 499    pub fn on_drag<T, W>(
 500        &mut self,
 501        value: T,
 502        constructor: impl Fn(&T, Point<Pixels>, &mut Window, &mut App) -> Entity<W> + 'static,
 503    ) where
 504        Self: Sized,
 505        T: 'static,
 506        W: 'static + Render,
 507    {
 508        debug_assert!(
 509            self.drag_listener.is_none(),
 510            "calling on_drag more than once on the same element is not supported"
 511        );
 512        self.drag_listener = Some((
 513            Arc::new(value),
 514            Box::new(move |value, offset, window, cx| {
 515                constructor(value.downcast_ref().unwrap(), offset, window, cx).into()
 516            }),
 517        ));
 518    }
 519
 520    /// Bind the given callback on the hover start and end events of this element. Note that the boolean
 521    /// passed to the callback is true when the hover starts and false when it ends.
 522    /// The imperative API equivalent to [`StatefulInteractiveElement::on_hover`]
 523    ///
 524    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 525    pub fn on_hover(&mut self, listener: impl Fn(&bool, &mut Window, &mut App) + 'static)
 526    where
 527        Self: Sized,
 528    {
 529        debug_assert!(
 530            self.hover_listener.is_none(),
 531            "calling on_hover more than once on the same element is not supported"
 532        );
 533        self.hover_listener = Some(Box::new(listener));
 534    }
 535
 536    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
 537    /// The imperative API equivalent to [`InteractiveElement::tooltip`]
 538    pub fn tooltip(&mut self, build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static)
 539    where
 540        Self: Sized,
 541    {
 542        debug_assert!(
 543            self.tooltip_builder.is_none(),
 544            "calling tooltip more than once on the same element is not supported"
 545        );
 546        self.tooltip_builder = Some(TooltipBuilder {
 547            build: Rc::new(build_tooltip),
 548            hoverable: false,
 549        });
 550    }
 551
 552    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
 553    /// The tooltip itself is also hoverable and won't disappear when the user moves the mouse into
 554    /// the tooltip. The imperative API equivalent to [`InteractiveElement::hoverable_tooltip`]
 555    pub fn hoverable_tooltip(
 556        &mut self,
 557        build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static,
 558    ) where
 559        Self: Sized,
 560    {
 561        debug_assert!(
 562            self.tooltip_builder.is_none(),
 563            "calling tooltip more than once on the same element is not supported"
 564        );
 565        self.tooltip_builder = Some(TooltipBuilder {
 566            build: Rc::new(build_tooltip),
 567            hoverable: true,
 568        });
 569    }
 570
 571    /// Block the mouse from all interactions with elements behind this element's hitbox. Typically
 572    /// `block_mouse_except_scroll` should be preferred.
 573    ///
 574    /// The imperative API equivalent to [`InteractiveElement::occlude`]
 575    pub fn occlude_mouse(&mut self) {
 576        self.hitbox_behavior = HitboxBehavior::BlockMouse;
 577    }
 578
 579    /// Set the bounds of this element as a window control area for the platform window.
 580    /// The imperative API equivalent to [`InteractiveElement::window_control_area`]
 581    pub fn window_control_area(&mut self, area: WindowControlArea) {
 582        self.window_control = Some(area);
 583    }
 584
 585    /// Block non-scroll mouse interactions with elements behind this element's hitbox. See
 586    /// [`Hitbox::is_hovered`] for details.
 587    ///
 588    /// The imperative API equivalent to [`InteractiveElement::block_mouse_except_scroll`]
 589    pub fn block_mouse_except_scroll(&mut self) {
 590        self.hitbox_behavior = HitboxBehavior::BlockMouseExceptScroll;
 591    }
 592}
 593
 594/// A trait for elements that want to use the standard GPUI event handlers that don't
 595/// require any state.
 596pub trait InteractiveElement: Sized {
 597    /// Retrieve the interactivity state associated with this element
 598    fn interactivity(&mut self) -> &mut Interactivity;
 599
 600    /// Assign this element to a group of elements that can be styled together
 601    fn group(mut self, group: impl Into<SharedString>) -> Self {
 602        self.interactivity().group = Some(group.into());
 603        self
 604    }
 605
 606    /// Assign this element an ID, so that it can be used with interactivity
 607    fn id(mut self, id: impl Into<ElementId>) -> Stateful<Self> {
 608        self.interactivity().element_id = Some(id.into());
 609
 610        Stateful { element: self }
 611    }
 612
 613    /// Track the focus state of the given focus handle on this element.
 614    /// If the focus handle is focused by the application, this element will
 615    /// apply its focused styles.
 616    fn track_focus(mut self, focus_handle: &FocusHandle) -> Self {
 617        self.interactivity().focusable = true;
 618        self.interactivity().tracked_focus_handle = Some(focus_handle.clone());
 619        self
 620    }
 621
 622    /// Set index of the tab stop order.
 623    fn tab_index(mut self, index: isize) -> Self {
 624        self.interactivity().focusable = true;
 625        self.interactivity().tab_index = Some(index);
 626        self
 627    }
 628
 629    /// Set the keymap context for this element. This will be used to determine
 630    /// which action to dispatch from the keymap.
 631    fn key_context<C, E>(mut self, key_context: C) -> Self
 632    where
 633        C: TryInto<KeyContext, Error = E>,
 634        E: Debug,
 635    {
 636        if let Some(key_context) = key_context.try_into().log_err() {
 637            self.interactivity().key_context = Some(key_context);
 638        }
 639        self
 640    }
 641
 642    /// Apply the given style to this element when the mouse hovers over it
 643    fn hover(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self {
 644        debug_assert!(
 645            self.interactivity().hover_style.is_none(),
 646            "hover style already set"
 647        );
 648        self.interactivity().hover_style = Some(Box::new(f(StyleRefinement::default())));
 649        self
 650    }
 651
 652    /// Apply the given style to this element when the mouse hovers over a group member
 653    fn group_hover(
 654        mut self,
 655        group_name: impl Into<SharedString>,
 656        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
 657    ) -> Self {
 658        self.interactivity().group_hover_style = Some(GroupStyle {
 659            group: group_name.into(),
 660            style: Box::new(f(StyleRefinement::default())),
 661        });
 662        self
 663    }
 664
 665    /// Bind the given callback to the mouse down event for the given mouse button,
 666    /// the fluent API equivalent to [`Interactivity::on_mouse_down`]
 667    ///
 668    /// See [`Context::listener`](crate::Context::listener) to get access to the view state from this callback.
 669    fn on_mouse_down(
 670        mut self,
 671        button: MouseButton,
 672        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 673    ) -> Self {
 674        self.interactivity().on_mouse_down(button, listener);
 675        self
 676    }
 677
 678    #[cfg(any(test, feature = "test-support"))]
 679    /// Set a key that can be used to look up this element's bounds
 680    /// in the [`VisualTestContext::debug_bounds`] map
 681    /// This is a noop in release builds
 682    fn debug_selector(mut self, f: impl FnOnce() -> String) -> Self {
 683        self.interactivity().debug_selector = Some(f());
 684        self
 685    }
 686
 687    #[cfg(not(any(test, feature = "test-support")))]
 688    /// Set a key that can be used to look up this element's bounds
 689    /// in the [`VisualTestContext::debug_bounds`] map
 690    /// This is a noop in release builds
 691    #[inline]
 692    fn debug_selector(self, _: impl FnOnce() -> String) -> Self {
 693        self
 694    }
 695
 696    /// Bind the given callback to the mouse down event for any button, during the capture phase
 697    /// the fluent API equivalent to [`Interactivity::capture_any_mouse_down`]
 698    ///
 699    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 700    fn capture_any_mouse_down(
 701        mut self,
 702        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 703    ) -> Self {
 704        self.interactivity().capture_any_mouse_down(listener);
 705        self
 706    }
 707
 708    /// Bind the given callback to the mouse down event for any button, during the capture phase
 709    /// the fluent API equivalent to [`Interactivity::on_any_mouse_down`]
 710    ///
 711    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 712    fn on_any_mouse_down(
 713        mut self,
 714        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 715    ) -> Self {
 716        self.interactivity().on_any_mouse_down(listener);
 717        self
 718    }
 719
 720    /// Bind the given callback to the mouse up event for the given button, during the bubble phase
 721    /// the fluent API equivalent to [`Interactivity::on_mouse_up`]
 722    ///
 723    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 724    fn on_mouse_up(
 725        mut self,
 726        button: MouseButton,
 727        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 728    ) -> Self {
 729        self.interactivity().on_mouse_up(button, listener);
 730        self
 731    }
 732
 733    /// Bind the given callback to the mouse up event for any button, during the capture phase
 734    /// the fluent API equivalent to [`Interactivity::capture_any_mouse_up`]
 735    ///
 736    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 737    fn capture_any_mouse_up(
 738        mut self,
 739        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 740    ) -> Self {
 741        self.interactivity().capture_any_mouse_up(listener);
 742        self
 743    }
 744
 745    /// Bind the given callback to the mouse down event, on any button, during the capture phase,
 746    /// when the mouse is outside of the bounds of this element.
 747    /// The fluent API equivalent to [`Interactivity::on_mouse_down_out`]
 748    ///
 749    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 750    fn on_mouse_down_out(
 751        mut self,
 752        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 753    ) -> Self {
 754        self.interactivity().on_mouse_down_out(listener);
 755        self
 756    }
 757
 758    /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
 759    /// when the mouse is outside of the bounds of this element.
 760    /// The fluent API equivalent to [`Interactivity::on_mouse_up_out`]
 761    ///
 762    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 763    fn on_mouse_up_out(
 764        mut self,
 765        button: MouseButton,
 766        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 767    ) -> Self {
 768        self.interactivity().on_mouse_up_out(button, listener);
 769        self
 770    }
 771
 772    /// Bind the given callback to the mouse move event, during the bubble phase
 773    /// The fluent API equivalent to [`Interactivity::on_mouse_move`]
 774    ///
 775    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 776    fn on_mouse_move(
 777        mut self,
 778        listener: impl Fn(&MouseMoveEvent, &mut Window, &mut App) + 'static,
 779    ) -> Self {
 780        self.interactivity().on_mouse_move(listener);
 781        self
 782    }
 783
 784    /// Bind the given callback to the mouse drag event of the given type. Note that this
 785    /// will be called for all move events, inside or outside of this element, as long as the
 786    /// drag was started with this element under the mouse. Useful for implementing draggable
 787    /// UIs that don't conform to a drag and drop style interaction, like resizing.
 788    /// The fluent API equivalent to [`Interactivity::on_drag_move`]
 789    ///
 790    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 791    fn on_drag_move<T: 'static>(
 792        mut self,
 793        listener: impl Fn(&DragMoveEvent<T>, &mut Window, &mut App) + 'static,
 794    ) -> Self {
 795        self.interactivity().on_drag_move(listener);
 796        self
 797    }
 798
 799    /// Bind the given callback to scroll wheel events during the bubble phase
 800    /// The fluent API equivalent to [`Interactivity::on_scroll_wheel`]
 801    ///
 802    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 803    fn on_scroll_wheel(
 804        mut self,
 805        listener: impl Fn(&ScrollWheelEvent, &mut Window, &mut App) + 'static,
 806    ) -> Self {
 807        self.interactivity().on_scroll_wheel(listener);
 808        self
 809    }
 810
 811    /// Capture the given action, before normal action dispatch can fire
 812    /// The fluent API equivalent to [`Interactivity::on_scroll_wheel`]
 813    ///
 814    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 815    fn capture_action<A: Action>(
 816        mut self,
 817        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
 818    ) -> Self {
 819        self.interactivity().capture_action(listener);
 820        self
 821    }
 822
 823    /// Bind the given callback to an action dispatch during the bubble phase
 824    /// The fluent API equivalent to [`Interactivity::on_action`]
 825    ///
 826    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 827    fn on_action<A: Action>(
 828        mut self,
 829        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
 830    ) -> Self {
 831        self.interactivity().on_action(listener);
 832        self
 833    }
 834
 835    /// Bind the given callback to an action dispatch, based on a dynamic action parameter
 836    /// instead of a type parameter. Useful for component libraries that want to expose
 837    /// action bindings to their users.
 838    /// The fluent API equivalent to [`Interactivity::on_boxed_action`]
 839    ///
 840    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 841    fn on_boxed_action(
 842        mut self,
 843        action: &dyn Action,
 844        listener: impl Fn(&dyn Action, &mut Window, &mut App) + 'static,
 845    ) -> Self {
 846        self.interactivity().on_boxed_action(action, listener);
 847        self
 848    }
 849
 850    /// Bind the given callback to key down events during the bubble phase
 851    /// The fluent API equivalent to [`Interactivity::on_key_down`]
 852    ///
 853    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 854    fn on_key_down(
 855        mut self,
 856        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
 857    ) -> Self {
 858        self.interactivity().on_key_down(listener);
 859        self
 860    }
 861
 862    /// Bind the given callback to key down events during the capture phase
 863    /// The fluent API equivalent to [`Interactivity::capture_key_down`]
 864    ///
 865    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 866    fn capture_key_down(
 867        mut self,
 868        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
 869    ) -> Self {
 870        self.interactivity().capture_key_down(listener);
 871        self
 872    }
 873
 874    /// Bind the given callback to key up events during the bubble phase
 875    /// The fluent API equivalent to [`Interactivity::on_key_up`]
 876    ///
 877    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 878    fn on_key_up(
 879        mut self,
 880        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
 881    ) -> Self {
 882        self.interactivity().on_key_up(listener);
 883        self
 884    }
 885
 886    /// Bind the given callback to key up events during the capture phase
 887    /// The fluent API equivalent to [`Interactivity::capture_key_up`]
 888    ///
 889    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 890    fn capture_key_up(
 891        mut self,
 892        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
 893    ) -> Self {
 894        self.interactivity().capture_key_up(listener);
 895        self
 896    }
 897
 898    /// Bind the given callback to modifiers changing events.
 899    /// The fluent API equivalent to [`Interactivity::on_modifiers_changed`]
 900    ///
 901    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 902    fn on_modifiers_changed(
 903        mut self,
 904        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
 905    ) -> Self {
 906        self.interactivity().on_modifiers_changed(listener);
 907        self
 908    }
 909
 910    /// Apply the given style when the given data type is dragged over this element
 911    fn drag_over<S: 'static>(
 912        mut self,
 913        f: impl 'static + Fn(StyleRefinement, &S, &mut Window, &mut App) -> StyleRefinement,
 914    ) -> Self {
 915        self.interactivity().drag_over_styles.push((
 916            TypeId::of::<S>(),
 917            Box::new(move |currently_dragged: &dyn Any, window, cx| {
 918                f(
 919                    StyleRefinement::default(),
 920                    currently_dragged.downcast_ref::<S>().unwrap(),
 921                    window,
 922                    cx,
 923                )
 924            }),
 925        ));
 926        self
 927    }
 928
 929    /// Apply the given style when the given data type is dragged over this element's group
 930    fn group_drag_over<S: 'static>(
 931        mut self,
 932        group_name: impl Into<SharedString>,
 933        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
 934    ) -> Self {
 935        self.interactivity().group_drag_over_styles.push((
 936            TypeId::of::<S>(),
 937            GroupStyle {
 938                group: group_name.into(),
 939                style: Box::new(f(StyleRefinement::default())),
 940            },
 941        ));
 942        self
 943    }
 944
 945    /// Bind the given callback to drop events of the given type, whether or not the drag started on this element
 946    /// The fluent API equivalent to [`Interactivity::on_drop`]
 947    ///
 948    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 949    fn on_drop<T: 'static>(
 950        mut self,
 951        listener: impl Fn(&T, &mut Window, &mut App) + 'static,
 952    ) -> Self {
 953        self.interactivity().on_drop(listener);
 954        self
 955    }
 956
 957    /// Use the given predicate to determine whether or not a drop event should be dispatched to this element
 958    /// The fluent API equivalent to [`Interactivity::can_drop`]
 959    fn can_drop(
 960        mut self,
 961        predicate: impl Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static,
 962    ) -> Self {
 963        self.interactivity().can_drop(predicate);
 964        self
 965    }
 966
 967    /// Block the mouse from all interactions with elements behind this element's hitbox. Typically
 968    /// `block_mouse_except_scroll` should be preferred.
 969    /// The fluent API equivalent to [`Interactivity::occlude_mouse`]
 970    fn occlude(mut self) -> Self {
 971        self.interactivity().occlude_mouse();
 972        self
 973    }
 974
 975    /// Set the bounds of this element as a window control area for the platform window.
 976    /// The fluent API equivalent to [`Interactivity::window_control_area`]
 977    fn window_control_area(mut self, area: WindowControlArea) -> Self {
 978        self.interactivity().window_control_area(area);
 979        self
 980    }
 981
 982    /// Block non-scroll mouse interactions with elements behind this element's hitbox. See
 983    /// [`Hitbox::is_hovered`] for details.
 984    ///
 985    /// The fluent API equivalent to [`Interactivity::block_mouse_except_scroll`]
 986    fn block_mouse_except_scroll(mut self) -> Self {
 987        self.interactivity().block_mouse_except_scroll();
 988        self
 989    }
 990
 991    /// Set the given styles to be applied when this element, specifically, is focused.
 992    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
 993    fn focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
 994    where
 995        Self: Sized,
 996    {
 997        self.interactivity().focus_style = Some(Box::new(f(StyleRefinement::default())));
 998        self
 999    }
1000
1001    /// Set the given styles to be applied when this element is inside another element that is focused.
1002    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
1003    fn in_focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1004    where
1005        Self: Sized,
1006    {
1007        self.interactivity().in_focus_style = Some(Box::new(f(StyleRefinement::default())));
1008        self
1009    }
1010}
1011
1012/// A trait for elements that want to use the standard GPUI interactivity features
1013/// that require state.
1014pub trait StatefulInteractiveElement: InteractiveElement {
1015    /// Set this element to focusable.
1016    fn focusable(mut self) -> Self {
1017        self.interactivity().focusable = true;
1018        self
1019    }
1020
1021    /// Set the overflow x and y to scroll.
1022    fn overflow_scroll(mut self) -> Self {
1023        self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
1024        self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
1025        self
1026    }
1027
1028    /// Set the overflow x to scroll.
1029    fn overflow_x_scroll(mut self) -> Self {
1030        self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
1031        self
1032    }
1033
1034    /// Set the overflow y to scroll.
1035    fn overflow_y_scroll(mut self) -> Self {
1036        self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
1037        self
1038    }
1039
1040    /// Track the scroll state of this element with the given handle.
1041    fn track_scroll(mut self, scroll_handle: &ScrollHandle) -> Self {
1042        self.interactivity().tracked_scroll_handle = Some(scroll_handle.clone());
1043        self
1044    }
1045
1046    /// Track the scroll state of this element with the given handle.
1047    fn anchor_scroll(mut self, scroll_anchor: Option<ScrollAnchor>) -> Self {
1048        self.interactivity().scroll_anchor = scroll_anchor;
1049        self
1050    }
1051
1052    /// Set the given styles to be applied when this element is active.
1053    fn active(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1054    where
1055        Self: Sized,
1056    {
1057        self.interactivity().active_style = Some(Box::new(f(StyleRefinement::default())));
1058        self
1059    }
1060
1061    /// Set the given styles to be applied when this element's group is active.
1062    fn group_active(
1063        mut self,
1064        group_name: impl Into<SharedString>,
1065        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
1066    ) -> Self
1067    where
1068        Self: Sized,
1069    {
1070        self.interactivity().group_active_style = Some(GroupStyle {
1071            group: group_name.into(),
1072            style: Box::new(f(StyleRefinement::default())),
1073        });
1074        self
1075    }
1076
1077    /// Bind the given callback to click events of this element
1078    /// The fluent API equivalent to [`Interactivity::on_click`]
1079    ///
1080    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1081    fn on_click(mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static) -> Self
1082    where
1083        Self: Sized,
1084    {
1085        self.interactivity().on_click(listener);
1086        self
1087    }
1088
1089    /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
1090    /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
1091    /// the [`Self::on_drag_move`] API.
1092    /// The callback also has access to the offset of triggering click from the origin of parent element.
1093    /// The fluent API equivalent to [`Interactivity::on_drag`]
1094    ///
1095    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1096    fn on_drag<T, W>(
1097        mut self,
1098        value: T,
1099        constructor: impl Fn(&T, Point<Pixels>, &mut Window, &mut App) -> Entity<W> + 'static,
1100    ) -> Self
1101    where
1102        Self: Sized,
1103        T: 'static,
1104        W: 'static + Render,
1105    {
1106        self.interactivity().on_drag(value, constructor);
1107        self
1108    }
1109
1110    /// Bind the given callback on the hover start and end events of this element. Note that the boolean
1111    /// passed to the callback is true when the hover starts and false when it ends.
1112    /// The fluent API equivalent to [`Interactivity::on_hover`]
1113    ///
1114    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1115    fn on_hover(mut self, listener: impl Fn(&bool, &mut Window, &mut App) + 'static) -> Self
1116    where
1117        Self: Sized,
1118    {
1119        self.interactivity().on_hover(listener);
1120        self
1121    }
1122
1123    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
1124    /// The fluent API equivalent to [`Interactivity::tooltip`]
1125    fn tooltip(mut self, build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static) -> Self
1126    where
1127        Self: Sized,
1128    {
1129        self.interactivity().tooltip(build_tooltip);
1130        self
1131    }
1132
1133    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
1134    /// The tooltip itself is also hoverable and won't disappear when the user moves the mouse into
1135    /// the tooltip. The fluent API equivalent to [`Interactivity::hoverable_tooltip`]
1136    fn hoverable_tooltip(
1137        mut self,
1138        build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static,
1139    ) -> Self
1140    where
1141        Self: Sized,
1142    {
1143        self.interactivity().hoverable_tooltip(build_tooltip);
1144        self
1145    }
1146}
1147
1148pub(crate) type MouseDownListener =
1149    Box<dyn Fn(&MouseDownEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1150pub(crate) type MouseUpListener =
1151    Box<dyn Fn(&MouseUpEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1152
1153pub(crate) type MouseMoveListener =
1154    Box<dyn Fn(&MouseMoveEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1155
1156pub(crate) type ScrollWheelListener =
1157    Box<dyn Fn(&ScrollWheelEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1158
1159pub(crate) type ClickListener = Box<dyn Fn(&ClickEvent, &mut Window, &mut App) + 'static>;
1160
1161pub(crate) type DragListener =
1162    Box<dyn Fn(&dyn Any, Point<Pixels>, &mut Window, &mut App) -> AnyView + 'static>;
1163
1164type DropListener = Box<dyn Fn(&dyn Any, &mut Window, &mut App) + 'static>;
1165
1166type CanDropPredicate = Box<dyn Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static>;
1167
1168pub(crate) struct TooltipBuilder {
1169    build: Rc<dyn Fn(&mut Window, &mut App) -> AnyView + 'static>,
1170    hoverable: bool,
1171}
1172
1173pub(crate) type KeyDownListener =
1174    Box<dyn Fn(&KeyDownEvent, DispatchPhase, &mut Window, &mut App) + 'static>;
1175
1176pub(crate) type KeyUpListener =
1177    Box<dyn Fn(&KeyUpEvent, DispatchPhase, &mut Window, &mut App) + 'static>;
1178
1179pub(crate) type ModifiersChangedListener =
1180    Box<dyn Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static>;
1181
1182pub(crate) type ActionListener =
1183    Box<dyn Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
1184
1185/// Construct a new [`Div`] element
1186#[track_caller]
1187pub fn div() -> Div {
1188    Div {
1189        interactivity: Interactivity::new(),
1190        children: SmallVec::default(),
1191        prepaint_listener: None,
1192        image_cache: None,
1193    }
1194}
1195
1196/// A [`Div`] element, the all-in-one element for building complex UIs in GPUI
1197pub struct Div {
1198    interactivity: Interactivity,
1199    children: SmallVec<[AnyElement; 2]>,
1200    prepaint_listener: Option<Box<dyn Fn(Vec<Bounds<Pixels>>, &mut Window, &mut App) + 'static>>,
1201    image_cache: Option<Box<dyn ImageCacheProvider>>,
1202}
1203
1204impl Div {
1205    /// Add a listener to be called when the children of this `Div` are prepainted.
1206    /// This allows you to store the [`Bounds`] of the children for later use.
1207    pub fn on_children_prepainted(
1208        mut self,
1209        listener: impl Fn(Vec<Bounds<Pixels>>, &mut Window, &mut App) + 'static,
1210    ) -> Self {
1211        self.prepaint_listener = Some(Box::new(listener));
1212        self
1213    }
1214
1215    /// Add an image cache at the location of this div in the element tree.
1216    pub fn image_cache(mut self, cache: impl ImageCacheProvider) -> Self {
1217        self.image_cache = Some(Box::new(cache));
1218        self
1219    }
1220}
1221
1222/// A frame state for a `Div` element, which contains layout IDs for its children.
1223///
1224/// This struct is used internally by the `Div` element to manage the layout state of its children
1225/// during the UI update cycle. It holds a small vector of `LayoutId` values, each corresponding to
1226/// a child element of the `Div`. These IDs are used to query the layout engine for the computed
1227/// bounds of the children after the layout phase is complete.
1228pub struct DivFrameState {
1229    child_layout_ids: SmallVec<[LayoutId; 2]>,
1230}
1231
1232/// Interactivity state displayed an manipulated in the inspector.
1233#[derive(Clone)]
1234pub struct DivInspectorState {
1235    /// The inspected element's base style. This is used for both inspecting and modifying the
1236    /// state. In the future it will make sense to separate the read and write, possibly tracking
1237    /// the modifications.
1238    #[cfg(any(feature = "inspector", debug_assertions))]
1239    pub base_style: Box<StyleRefinement>,
1240    /// Inspects the bounds of the element.
1241    pub bounds: Bounds<Pixels>,
1242    /// Size of the children of the element, or `bounds.size` if it has no children.
1243    pub content_size: Size<Pixels>,
1244}
1245
1246impl Styled for Div {
1247    fn style(&mut self) -> &mut StyleRefinement {
1248        &mut self.interactivity.base_style
1249    }
1250}
1251
1252impl InteractiveElement for Div {
1253    fn interactivity(&mut self) -> &mut Interactivity {
1254        &mut self.interactivity
1255    }
1256}
1257
1258impl ParentElement for Div {
1259    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
1260        self.children.extend(elements)
1261    }
1262}
1263
1264impl Element for Div {
1265    type RequestLayoutState = DivFrameState;
1266    type PrepaintState = Option<Hitbox>;
1267
1268    fn id(&self) -> Option<ElementId> {
1269        self.interactivity.element_id.clone()
1270    }
1271
1272    fn source_location(&self) -> Option<&'static std::panic::Location<'static>> {
1273        self.interactivity.source_location()
1274    }
1275
1276    fn request_layout(
1277        &mut self,
1278        global_id: Option<&GlobalElementId>,
1279        inspector_id: Option<&InspectorElementId>,
1280        window: &mut Window,
1281        cx: &mut App,
1282    ) -> (LayoutId, Self::RequestLayoutState) {
1283        let mut child_layout_ids = SmallVec::new();
1284        let image_cache = self
1285            .image_cache
1286            .as_mut()
1287            .map(|provider| provider.provide(window, cx));
1288
1289        let layout_id = window.with_image_cache(image_cache, |window| {
1290            self.interactivity.request_layout(
1291                global_id,
1292                inspector_id,
1293                window,
1294                cx,
1295                |style, window, cx| {
1296                    window.with_text_style(style.text_style().cloned(), |window| {
1297                        child_layout_ids = self
1298                            .children
1299                            .iter_mut()
1300                            .map(|child| child.request_layout(window, cx))
1301                            .collect::<SmallVec<_>>();
1302                        window.request_layout(style, child_layout_ids.iter().copied(), cx)
1303                    })
1304                },
1305            )
1306        });
1307
1308        (layout_id, DivFrameState { child_layout_ids })
1309    }
1310
1311    fn prepaint(
1312        &mut self,
1313        global_id: Option<&GlobalElementId>,
1314        inspector_id: Option<&InspectorElementId>,
1315        bounds: Bounds<Pixels>,
1316        request_layout: &mut Self::RequestLayoutState,
1317        window: &mut Window,
1318        cx: &mut App,
1319    ) -> Option<Hitbox> {
1320        let has_prepaint_listener = self.prepaint_listener.is_some();
1321        let mut children_bounds = Vec::with_capacity(if has_prepaint_listener {
1322            request_layout.child_layout_ids.len()
1323        } else {
1324            0
1325        });
1326
1327        let mut child_min = point(Pixels::MAX, Pixels::MAX);
1328        let mut child_max = Point::default();
1329        if let Some(handle) = self.interactivity.scroll_anchor.as_ref() {
1330            *handle.last_origin.borrow_mut() = bounds.origin - window.element_offset();
1331        }
1332        let content_size = if request_layout.child_layout_ids.is_empty() {
1333            bounds.size
1334        } else if let Some(scroll_handle) = self.interactivity.tracked_scroll_handle.as_ref() {
1335            let mut state = scroll_handle.0.borrow_mut();
1336            state.child_bounds = Vec::with_capacity(request_layout.child_layout_ids.len());
1337            state.bounds = bounds;
1338            for child_layout_id in &request_layout.child_layout_ids {
1339                let child_bounds = window.layout_bounds(*child_layout_id);
1340                child_min = child_min.min(&child_bounds.origin);
1341                child_max = child_max.max(&child_bounds.bottom_right());
1342                state.child_bounds.push(child_bounds);
1343            }
1344            (child_max - child_min).into()
1345        } else {
1346            for child_layout_id in &request_layout.child_layout_ids {
1347                let child_bounds = window.layout_bounds(*child_layout_id);
1348                child_min = child_min.min(&child_bounds.origin);
1349                child_max = child_max.max(&child_bounds.bottom_right());
1350
1351                if has_prepaint_listener {
1352                    children_bounds.push(child_bounds);
1353                }
1354            }
1355            (child_max - child_min).into()
1356        };
1357
1358        self.interactivity.prepaint(
1359            global_id,
1360            inspector_id,
1361            bounds,
1362            content_size,
1363            window,
1364            cx,
1365            |_style, scroll_offset, hitbox, window, cx| {
1366                window.with_element_offset(scroll_offset, |window| {
1367                    for child in &mut self.children {
1368                        child.prepaint(window, cx);
1369                    }
1370                });
1371
1372                if let Some(listener) = self.prepaint_listener.as_ref() {
1373                    listener(children_bounds, window, cx);
1374                }
1375
1376                hitbox
1377            },
1378        )
1379    }
1380
1381    fn paint(
1382        &mut self,
1383        global_id: Option<&GlobalElementId>,
1384        inspector_id: Option<&InspectorElementId>,
1385        bounds: Bounds<Pixels>,
1386        _request_layout: &mut Self::RequestLayoutState,
1387        hitbox: &mut Option<Hitbox>,
1388        window: &mut Window,
1389        cx: &mut App,
1390    ) {
1391        let image_cache = self
1392            .image_cache
1393            .as_mut()
1394            .map(|provider| provider.provide(window, cx));
1395
1396        window.with_image_cache(image_cache, |window| {
1397            self.interactivity.paint(
1398                global_id,
1399                inspector_id,
1400                bounds,
1401                hitbox.as_ref(),
1402                window,
1403                cx,
1404                |_style, window, cx| {
1405                    for child in &mut self.children {
1406                        child.paint(window, cx);
1407                    }
1408                },
1409            )
1410        });
1411    }
1412}
1413
1414impl IntoElement for Div {
1415    type Element = Self;
1416
1417    fn into_element(self) -> Self::Element {
1418        self
1419    }
1420}
1421
1422/// The interactivity struct. Powers all of the general-purpose
1423/// interactivity in the `Div` element.
1424#[derive(Default)]
1425pub struct Interactivity {
1426    /// The element ID of the element. In id is required to support a stateful subset of the interactivity such as on_click.
1427    pub element_id: Option<ElementId>,
1428    /// Whether the element was clicked. This will only be present after layout.
1429    pub active: Option<bool>,
1430    /// Whether the element was hovered. This will only be present after paint if an hitbox
1431    /// was created for the interactive element.
1432    pub hovered: Option<bool>,
1433    pub(crate) tooltip_id: Option<TooltipId>,
1434    pub(crate) content_size: Size<Pixels>,
1435    pub(crate) key_context: Option<KeyContext>,
1436    pub(crate) focusable: bool,
1437    pub(crate) tracked_focus_handle: Option<FocusHandle>,
1438    pub(crate) tracked_scroll_handle: Option<ScrollHandle>,
1439    pub(crate) scroll_anchor: Option<ScrollAnchor>,
1440    pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
1441    pub(crate) group: Option<SharedString>,
1442    /// The base style of the element, before any modifications are applied
1443    /// by focus, active, etc.
1444    pub base_style: Box<StyleRefinement>,
1445    pub(crate) focus_style: Option<Box<StyleRefinement>>,
1446    pub(crate) in_focus_style: Option<Box<StyleRefinement>>,
1447    pub(crate) hover_style: Option<Box<StyleRefinement>>,
1448    pub(crate) group_hover_style: Option<GroupStyle>,
1449    pub(crate) active_style: Option<Box<StyleRefinement>>,
1450    pub(crate) group_active_style: Option<GroupStyle>,
1451    pub(crate) drag_over_styles: Vec<(
1452        TypeId,
1453        Box<dyn Fn(&dyn Any, &mut Window, &mut App) -> StyleRefinement>,
1454    )>,
1455    pub(crate) group_drag_over_styles: Vec<(TypeId, GroupStyle)>,
1456    pub(crate) mouse_down_listeners: Vec<MouseDownListener>,
1457    pub(crate) mouse_up_listeners: Vec<MouseUpListener>,
1458    pub(crate) mouse_move_listeners: Vec<MouseMoveListener>,
1459    pub(crate) scroll_wheel_listeners: Vec<ScrollWheelListener>,
1460    pub(crate) key_down_listeners: Vec<KeyDownListener>,
1461    pub(crate) key_up_listeners: Vec<KeyUpListener>,
1462    pub(crate) modifiers_changed_listeners: Vec<ModifiersChangedListener>,
1463    pub(crate) action_listeners: Vec<(TypeId, ActionListener)>,
1464    pub(crate) drop_listeners: Vec<(TypeId, DropListener)>,
1465    pub(crate) can_drop_predicate: Option<CanDropPredicate>,
1466    pub(crate) click_listeners: Vec<ClickListener>,
1467    pub(crate) drag_listener: Option<(Arc<dyn Any>, DragListener)>,
1468    pub(crate) hover_listener: Option<Box<dyn Fn(&bool, &mut Window, &mut App)>>,
1469    pub(crate) tooltip_builder: Option<TooltipBuilder>,
1470    pub(crate) window_control: Option<WindowControlArea>,
1471    pub(crate) hitbox_behavior: HitboxBehavior,
1472    pub(crate) tab_index: Option<isize>,
1473
1474    #[cfg(any(feature = "inspector", debug_assertions))]
1475    pub(crate) source_location: Option<&'static core::panic::Location<'static>>,
1476
1477    #[cfg(any(test, feature = "test-support"))]
1478    pub(crate) debug_selector: Option<String>,
1479}
1480
1481impl Interactivity {
1482    /// Layout this element according to this interactivity state's configured styles
1483    pub fn request_layout(
1484        &mut self,
1485        global_id: Option<&GlobalElementId>,
1486        _inspector_id: Option<&InspectorElementId>,
1487        window: &mut Window,
1488        cx: &mut App,
1489        f: impl FnOnce(Style, &mut Window, &mut App) -> LayoutId,
1490    ) -> LayoutId {
1491        #[cfg(any(feature = "inspector", debug_assertions))]
1492        window.with_inspector_state(
1493            _inspector_id,
1494            cx,
1495            |inspector_state: &mut Option<DivInspectorState>, _window| {
1496                if let Some(inspector_state) = inspector_state {
1497                    self.base_style = inspector_state.base_style.clone();
1498                } else {
1499                    *inspector_state = Some(DivInspectorState {
1500                        base_style: self.base_style.clone(),
1501                        bounds: Default::default(),
1502                        content_size: Default::default(),
1503                    })
1504                }
1505            },
1506        );
1507
1508        window.with_optional_element_state::<InteractiveElementState, _>(
1509            global_id,
1510            |element_state, window| {
1511                let mut element_state =
1512                    element_state.map(|element_state| element_state.unwrap_or_default());
1513
1514                if let Some(element_state) = element_state.as_ref() {
1515                    if cx.has_active_drag() {
1516                        if let Some(pending_mouse_down) = element_state.pending_mouse_down.as_ref()
1517                        {
1518                            *pending_mouse_down.borrow_mut() = None;
1519                        }
1520                        if let Some(clicked_state) = element_state.clicked_state.as_ref() {
1521                            *clicked_state.borrow_mut() = ElementClickedState::default();
1522                        }
1523                    }
1524                }
1525
1526                // Ensure we store a focus handle in our element state if we're focusable.
1527                // If there's an explicit focus handle we're tracking, use that. Otherwise
1528                // create a new handle and store it in the element state, which lives for as
1529                // as frames contain an element with this id.
1530                if self.focusable && self.tracked_focus_handle.is_none() {
1531                    if let Some(element_state) = element_state.as_mut() {
1532                        let mut handle = element_state
1533                            .focus_handle
1534                            .get_or_insert_with(|| cx.focus_handle())
1535                            .clone()
1536                            .tab_stop(false);
1537
1538                        if let Some(index) = self.tab_index {
1539                            handle = handle.tab_index(index).tab_stop(true);
1540                        }
1541
1542                        self.tracked_focus_handle = Some(handle);
1543                    }
1544                }
1545
1546                if let Some(scroll_handle) = self.tracked_scroll_handle.as_ref() {
1547                    self.scroll_offset = Some(scroll_handle.0.borrow().offset.clone());
1548                } else if self.base_style.overflow.x == Some(Overflow::Scroll)
1549                    || self.base_style.overflow.y == Some(Overflow::Scroll)
1550                {
1551                    if let Some(element_state) = element_state.as_mut() {
1552                        self.scroll_offset = Some(
1553                            element_state
1554                                .scroll_offset
1555                                .get_or_insert_with(Rc::default)
1556                                .clone(),
1557                        );
1558                    }
1559                }
1560
1561                let style = self.compute_style_internal(None, element_state.as_mut(), window, cx);
1562                let layout_id = f(style, window, cx);
1563                (layout_id, element_state)
1564            },
1565        )
1566    }
1567
1568    /// Commit the bounds of this element according to this interactivity state's configured styles.
1569    pub fn prepaint<R>(
1570        &mut self,
1571        global_id: Option<&GlobalElementId>,
1572        _inspector_id: Option<&InspectorElementId>,
1573        bounds: Bounds<Pixels>,
1574        content_size: Size<Pixels>,
1575        window: &mut Window,
1576        cx: &mut App,
1577        f: impl FnOnce(&Style, Point<Pixels>, Option<Hitbox>, &mut Window, &mut App) -> R,
1578    ) -> R {
1579        self.content_size = content_size;
1580
1581        #[cfg(any(feature = "inspector", debug_assertions))]
1582        window.with_inspector_state(
1583            _inspector_id,
1584            cx,
1585            |inspector_state: &mut Option<DivInspectorState>, _window| {
1586                if let Some(inspector_state) = inspector_state {
1587                    inspector_state.bounds = bounds;
1588                    inspector_state.content_size = content_size;
1589                }
1590            },
1591        );
1592
1593        if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
1594            window.set_focus_handle(focus_handle, cx);
1595        }
1596        window.with_optional_element_state::<InteractiveElementState, _>(
1597            global_id,
1598            |element_state, window| {
1599                let mut element_state =
1600                    element_state.map(|element_state| element_state.unwrap_or_default());
1601                let style = self.compute_style_internal(None, element_state.as_mut(), window, cx);
1602
1603                if let Some(element_state) = element_state.as_mut() {
1604                    if let Some(clicked_state) = element_state.clicked_state.as_ref() {
1605                        let clicked_state = clicked_state.borrow();
1606                        self.active = Some(clicked_state.element);
1607                    }
1608                    if let Some(active_tooltip) = element_state.active_tooltip.as_ref() {
1609                        if self.tooltip_builder.is_some() {
1610                            self.tooltip_id = set_tooltip_on_window(active_tooltip, window);
1611                        } else {
1612                            // If there is no longer a tooltip builder, remove the active tooltip.
1613                            element_state.active_tooltip.take();
1614                        }
1615                    }
1616                }
1617
1618                window.with_text_style(style.text_style().cloned(), |window| {
1619                    window.with_content_mask(
1620                        style.overflow_mask(bounds, window.rem_size()),
1621                        |window| {
1622                            let hitbox = if self.should_insert_hitbox(&style, window, cx) {
1623                                Some(window.insert_hitbox(bounds, self.hitbox_behavior))
1624                            } else {
1625                                None
1626                            };
1627
1628                            let scroll_offset =
1629                                self.clamp_scroll_position(bounds, &style, window, cx);
1630                            let result = f(&style, scroll_offset, hitbox, window, cx);
1631                            (result, element_state)
1632                        },
1633                    )
1634                })
1635            },
1636        )
1637    }
1638
1639    fn should_insert_hitbox(&self, style: &Style, window: &Window, cx: &App) -> bool {
1640        self.hitbox_behavior != HitboxBehavior::Normal
1641            || self.window_control.is_some()
1642            || style.mouse_cursor.is_some()
1643            || self.group.is_some()
1644            || self.scroll_offset.is_some()
1645            || self.tracked_focus_handle.is_some()
1646            || self.hover_style.is_some()
1647            || self.group_hover_style.is_some()
1648            || self.hover_listener.is_some()
1649            || !self.mouse_up_listeners.is_empty()
1650            || !self.mouse_down_listeners.is_empty()
1651            || !self.mouse_move_listeners.is_empty()
1652            || !self.click_listeners.is_empty()
1653            || !self.scroll_wheel_listeners.is_empty()
1654            || self.drag_listener.is_some()
1655            || !self.drop_listeners.is_empty()
1656            || self.tooltip_builder.is_some()
1657            || window.is_inspector_picking(cx)
1658    }
1659
1660    fn clamp_scroll_position(
1661        &self,
1662        bounds: Bounds<Pixels>,
1663        style: &Style,
1664        window: &mut Window,
1665        _cx: &mut App,
1666    ) -> Point<Pixels> {
1667        if let Some(scroll_offset) = self.scroll_offset.as_ref() {
1668            let mut scroll_to_bottom = false;
1669            let mut tracked_scroll_handle = self
1670                .tracked_scroll_handle
1671                .as_ref()
1672                .map(|handle| handle.0.borrow_mut());
1673            if let Some(mut scroll_handle_state) = tracked_scroll_handle.as_deref_mut() {
1674                scroll_handle_state.overflow = style.overflow;
1675                scroll_to_bottom = mem::take(&mut scroll_handle_state.scroll_to_bottom);
1676            }
1677
1678            let rem_size = window.rem_size();
1679            let padding = style.padding.to_pixels(bounds.size.into(), rem_size);
1680            let padding_size = size(padding.left + padding.right, padding.top + padding.bottom);
1681            let padded_content_size = self.content_size + padding_size;
1682            let scroll_max = (padded_content_size - bounds.size).max(&Size::default());
1683            // Clamp scroll offset in case scroll max is smaller now (e.g., if children
1684            // were removed or the bounds became larger).
1685            let mut scroll_offset = scroll_offset.borrow_mut();
1686
1687            scroll_offset.x = scroll_offset.x.clamp(-scroll_max.width, px(0.));
1688            if scroll_to_bottom {
1689                scroll_offset.y = -scroll_max.height;
1690            } else {
1691                scroll_offset.y = scroll_offset.y.clamp(-scroll_max.height, px(0.));
1692            }
1693
1694            if let Some(mut scroll_handle_state) = tracked_scroll_handle {
1695                scroll_handle_state.padded_content_size = padded_content_size;
1696            }
1697
1698            *scroll_offset
1699        } else {
1700            Point::default()
1701        }
1702    }
1703
1704    /// Paint this element according to this interactivity state's configured styles
1705    /// and bind the element's mouse and keyboard events.
1706    ///
1707    /// content_size is the size of the content of the element, which may be larger than the
1708    /// element's bounds if the element is scrollable.
1709    ///
1710    /// the final computed style will be passed to the provided function, along
1711    /// with the current scroll offset
1712    pub fn paint(
1713        &mut self,
1714        global_id: Option<&GlobalElementId>,
1715        _inspector_id: Option<&InspectorElementId>,
1716        bounds: Bounds<Pixels>,
1717        hitbox: Option<&Hitbox>,
1718        window: &mut Window,
1719        cx: &mut App,
1720        f: impl FnOnce(&Style, &mut Window, &mut App),
1721    ) {
1722        self.hovered = hitbox.map(|hitbox| hitbox.is_hovered(window));
1723        window.with_optional_element_state::<InteractiveElementState, _>(
1724            global_id,
1725            |element_state, window| {
1726                let mut element_state =
1727                    element_state.map(|element_state| element_state.unwrap_or_default());
1728
1729                let style = self.compute_style_internal(hitbox, element_state.as_mut(), window, cx);
1730
1731                #[cfg(any(feature = "test-support", test))]
1732                if let Some(debug_selector) = &self.debug_selector {
1733                    window
1734                        .next_frame
1735                        .debug_bounds
1736                        .insert(debug_selector.clone(), bounds);
1737                }
1738
1739                self.paint_hover_group_handler(window, cx);
1740
1741                if style.visibility == Visibility::Hidden {
1742                    return ((), element_state);
1743                }
1744
1745                if let Some(focus_handle) = &self.tracked_focus_handle {
1746                    window.next_frame.tab_handles.insert(focus_handle);
1747                }
1748
1749                window.with_element_opacity(style.opacity, |window| {
1750                    style.paint(bounds, window, cx, |window: &mut Window, cx: &mut App| {
1751                        window.with_text_style(style.text_style().cloned(), |window| {
1752                            window.with_content_mask(
1753                                style.overflow_mask(bounds, window.rem_size()),
1754                                |window| {
1755                                    if let Some(hitbox) = hitbox {
1756                                        #[cfg(debug_assertions)]
1757                                        self.paint_debug_info(
1758                                            global_id, hitbox, &style, window, cx,
1759                                        );
1760
1761                                        if let Some(drag) = cx.active_drag.as_ref() {
1762                                            if let Some(mouse_cursor) = drag.cursor_style {
1763                                                window.set_window_cursor_style(mouse_cursor);
1764                                            }
1765                                        } else {
1766                                            if let Some(mouse_cursor) = style.mouse_cursor {
1767                                                window.set_cursor_style(mouse_cursor, hitbox);
1768                                            }
1769                                        }
1770
1771                                        if let Some(group) = self.group.clone() {
1772                                            GroupHitboxes::push(group, hitbox.id, cx);
1773                                        }
1774
1775                                        if let Some(area) = self.window_control {
1776                                            window
1777                                                .insert_window_control_hitbox(area, hitbox.clone());
1778                                        }
1779
1780                                        self.paint_mouse_listeners(
1781                                            hitbox,
1782                                            element_state.as_mut(),
1783                                            window,
1784                                            cx,
1785                                        );
1786                                        self.paint_scroll_listener(hitbox, &style, window, cx);
1787                                    }
1788
1789                                    self.paint_keyboard_listeners(window, cx);
1790                                    f(&style, window, cx);
1791
1792                                    if let Some(_hitbox) = hitbox {
1793                                        #[cfg(any(feature = "inspector", debug_assertions))]
1794                                        window.insert_inspector_hitbox(
1795                                            _hitbox.id,
1796                                            _inspector_id,
1797                                            cx,
1798                                        );
1799
1800                                        if let Some(group) = self.group.as_ref() {
1801                                            GroupHitboxes::pop(group, cx);
1802                                        }
1803                                    }
1804                                },
1805                            );
1806                        });
1807                    });
1808                });
1809
1810                ((), element_state)
1811            },
1812        );
1813    }
1814
1815    #[cfg(debug_assertions)]
1816    fn paint_debug_info(
1817        &self,
1818        global_id: Option<&GlobalElementId>,
1819        hitbox: &Hitbox,
1820        style: &Style,
1821        window: &mut Window,
1822        cx: &mut App,
1823    ) {
1824        use crate::{BorderStyle, TextAlign};
1825
1826        if global_id.is_some()
1827            && (style.debug || style.debug_below || cx.has_global::<crate::DebugBelow>())
1828            && hitbox.is_hovered(window)
1829        {
1830            const FONT_SIZE: crate::Pixels = crate::Pixels(10.);
1831            let element_id = format!("{:?}", global_id.unwrap());
1832            let str_len = element_id.len();
1833
1834            let render_debug_text = |window: &mut Window| {
1835                if let Some(text) = window
1836                    .text_system()
1837                    .shape_text(
1838                        element_id.into(),
1839                        FONT_SIZE,
1840                        &[window.text_style().to_run(str_len)],
1841                        None,
1842                        None,
1843                    )
1844                    .ok()
1845                    .and_then(|mut text| text.pop())
1846                {
1847                    text.paint(hitbox.origin, FONT_SIZE, TextAlign::Left, None, window, cx)
1848                        .ok();
1849
1850                    let text_bounds = crate::Bounds {
1851                        origin: hitbox.origin,
1852                        size: text.size(FONT_SIZE),
1853                    };
1854                    if self.source_location.is_some()
1855                        && text_bounds.contains(&window.mouse_position())
1856                        && window.modifiers().secondary()
1857                    {
1858                        let secondary_held = window.modifiers().secondary();
1859                        window.on_key_event({
1860                            move |e: &crate::ModifiersChangedEvent, _phase, window, _cx| {
1861                                if e.modifiers.secondary() != secondary_held
1862                                    && text_bounds.contains(&window.mouse_position())
1863                                {
1864                                    window.refresh();
1865                                }
1866                            }
1867                        });
1868
1869                        let was_hovered = hitbox.is_hovered(window);
1870                        let current_view = window.current_view();
1871                        window.on_mouse_event({
1872                            let hitbox = hitbox.clone();
1873                            move |_: &MouseMoveEvent, phase, window, cx| {
1874                                if phase == DispatchPhase::Capture {
1875                                    let hovered = hitbox.is_hovered(window);
1876                                    if hovered != was_hovered {
1877                                        cx.notify(current_view)
1878                                    }
1879                                }
1880                            }
1881                        });
1882
1883                        window.on_mouse_event({
1884                            let hitbox = hitbox.clone();
1885                            let location = self.source_location.unwrap();
1886                            move |e: &crate::MouseDownEvent, phase, window, cx| {
1887                                if text_bounds.contains(&e.position)
1888                                    && phase.capture()
1889                                    && hitbox.is_hovered(window)
1890                                {
1891                                    cx.stop_propagation();
1892                                    let Ok(dir) = std::env::current_dir() else {
1893                                        return;
1894                                    };
1895
1896                                    eprintln!(
1897                                        "This element was created at:\n{}:{}:{}",
1898                                        dir.join(location.file()).to_string_lossy(),
1899                                        location.line(),
1900                                        location.column()
1901                                    );
1902                                }
1903                            }
1904                        });
1905                        window.paint_quad(crate::outline(
1906                            crate::Bounds {
1907                                origin: hitbox.origin
1908                                    + crate::point(crate::px(0.), FONT_SIZE - px(2.)),
1909                                size: crate::Size {
1910                                    width: text_bounds.size.width,
1911                                    height: crate::px(1.),
1912                                },
1913                            },
1914                            crate::red(),
1915                            BorderStyle::default(),
1916                        ))
1917                    }
1918                }
1919            };
1920
1921            window.with_text_style(
1922                Some(crate::TextStyleRefinement {
1923                    color: Some(crate::red()),
1924                    line_height: Some(FONT_SIZE.into()),
1925                    background_color: Some(crate::white()),
1926                    ..Default::default()
1927                }),
1928                render_debug_text,
1929            )
1930        }
1931    }
1932
1933    fn paint_mouse_listeners(
1934        &mut self,
1935        hitbox: &Hitbox,
1936        element_state: Option<&mut InteractiveElementState>,
1937        window: &mut Window,
1938        cx: &mut App,
1939    ) {
1940        // If this element can be focused, register a mouse down listener
1941        // that will automatically transfer focus when hitting the element.
1942        // This behavior can be suppressed by using `cx.prevent_default()`.
1943        if let Some(focus_handle) = self.tracked_focus_handle.clone() {
1944            let hitbox = hitbox.clone();
1945            window.on_mouse_event(move |_: &MouseDownEvent, phase, window, _| {
1946                if phase == DispatchPhase::Bubble
1947                    && hitbox.is_hovered(window)
1948                    && !window.default_prevented()
1949                {
1950                    window.focus(&focus_handle);
1951                    // If there is a parent that is also focusable, prevent it
1952                    // from transferring focus because we already did so.
1953                    window.prevent_default();
1954                }
1955            });
1956        }
1957
1958        for listener in self.mouse_down_listeners.drain(..) {
1959            let hitbox = hitbox.clone();
1960            window.on_mouse_event(move |event: &MouseDownEvent, phase, window, cx| {
1961                listener(event, phase, &hitbox, window, cx);
1962            })
1963        }
1964
1965        for listener in self.mouse_up_listeners.drain(..) {
1966            let hitbox = hitbox.clone();
1967            window.on_mouse_event(move |event: &MouseUpEvent, phase, window, cx| {
1968                listener(event, phase, &hitbox, window, cx);
1969            })
1970        }
1971
1972        for listener in self.mouse_move_listeners.drain(..) {
1973            let hitbox = hitbox.clone();
1974            window.on_mouse_event(move |event: &MouseMoveEvent, phase, window, cx| {
1975                listener(event, phase, &hitbox, window, cx);
1976            })
1977        }
1978
1979        for listener in self.scroll_wheel_listeners.drain(..) {
1980            let hitbox = hitbox.clone();
1981            window.on_mouse_event(move |event: &ScrollWheelEvent, phase, window, cx| {
1982                listener(event, phase, &hitbox, window, cx);
1983            })
1984        }
1985
1986        if self.hover_style.is_some()
1987            || self.base_style.mouse_cursor.is_some()
1988            || cx.active_drag.is_some() && !self.drag_over_styles.is_empty()
1989        {
1990            let hitbox = hitbox.clone();
1991            let was_hovered = hitbox.is_hovered(window);
1992            let current_view = window.current_view();
1993            window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
1994                let hovered = hitbox.is_hovered(window);
1995                if phase == DispatchPhase::Capture && hovered != was_hovered {
1996                    cx.notify(current_view);
1997                }
1998            });
1999        }
2000        let drag_cursor_style = self.base_style.as_ref().mouse_cursor;
2001
2002        let mut drag_listener = mem::take(&mut self.drag_listener);
2003        let drop_listeners = mem::take(&mut self.drop_listeners);
2004        let click_listeners = mem::take(&mut self.click_listeners);
2005        let can_drop_predicate = mem::take(&mut self.can_drop_predicate);
2006
2007        if !drop_listeners.is_empty() {
2008            let hitbox = hitbox.clone();
2009            window.on_mouse_event({
2010                move |_: &MouseUpEvent, phase, window, cx| {
2011                    if let Some(drag) = &cx.active_drag {
2012                        if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
2013                            let drag_state_type = drag.value.as_ref().type_id();
2014                            for (drop_state_type, listener) in &drop_listeners {
2015                                if *drop_state_type == drag_state_type {
2016                                    let drag = cx
2017                                        .active_drag
2018                                        .take()
2019                                        .expect("checked for type drag state type above");
2020
2021                                    let mut can_drop = true;
2022                                    if let Some(predicate) = &can_drop_predicate {
2023                                        can_drop = predicate(drag.value.as_ref(), window, cx);
2024                                    }
2025
2026                                    if can_drop {
2027                                        listener(drag.value.as_ref(), window, cx);
2028                                        window.refresh();
2029                                        cx.stop_propagation();
2030                                    }
2031                                }
2032                            }
2033                        }
2034                    }
2035                }
2036            });
2037        }
2038
2039        if let Some(element_state) = element_state {
2040            if !click_listeners.is_empty() || drag_listener.is_some() {
2041                let pending_mouse_down = element_state
2042                    .pending_mouse_down
2043                    .get_or_insert_with(Default::default)
2044                    .clone();
2045
2046                let clicked_state = element_state
2047                    .clicked_state
2048                    .get_or_insert_with(Default::default)
2049                    .clone();
2050
2051                window.on_mouse_event({
2052                    let pending_mouse_down = pending_mouse_down.clone();
2053                    let hitbox = hitbox.clone();
2054                    move |event: &MouseDownEvent, phase, window, _cx| {
2055                        if phase == DispatchPhase::Bubble
2056                            && event.button == MouseButton::Left
2057                            && hitbox.is_hovered(window)
2058                        {
2059                            *pending_mouse_down.borrow_mut() = Some(event.clone());
2060                            window.refresh();
2061                        }
2062                    }
2063                });
2064
2065                window.on_mouse_event({
2066                    let pending_mouse_down = pending_mouse_down.clone();
2067                    let hitbox = hitbox.clone();
2068                    move |event: &MouseMoveEvent, phase, window, cx| {
2069                        if phase == DispatchPhase::Capture {
2070                            return;
2071                        }
2072
2073                        let mut pending_mouse_down = pending_mouse_down.borrow_mut();
2074                        if let Some(mouse_down) = pending_mouse_down.clone() {
2075                            if !cx.has_active_drag()
2076                                && (event.position - mouse_down.position).magnitude()
2077                                    > DRAG_THRESHOLD
2078                            {
2079                                if let Some((drag_value, drag_listener)) = drag_listener.take() {
2080                                    *clicked_state.borrow_mut() = ElementClickedState::default();
2081                                    let cursor_offset = event.position - hitbox.origin;
2082                                    let drag = (drag_listener)(
2083                                        drag_value.as_ref(),
2084                                        cursor_offset,
2085                                        window,
2086                                        cx,
2087                                    );
2088                                    cx.active_drag = Some(AnyDrag {
2089                                        view: drag,
2090                                        value: drag_value,
2091                                        cursor_offset,
2092                                        cursor_style: drag_cursor_style,
2093                                    });
2094                                    pending_mouse_down.take();
2095                                    window.refresh();
2096                                    cx.stop_propagation();
2097                                }
2098                            }
2099                        }
2100                    }
2101                });
2102
2103                window.on_mouse_event({
2104                    let mut captured_mouse_down = None;
2105                    let hitbox = hitbox.clone();
2106                    move |event: &MouseUpEvent, phase, window, cx| match phase {
2107                        // Clear the pending mouse down during the capture phase,
2108                        // so that it happens even if another event handler stops
2109                        // propagation.
2110                        DispatchPhase::Capture => {
2111                            let mut pending_mouse_down = pending_mouse_down.borrow_mut();
2112                            if pending_mouse_down.is_some() && hitbox.is_hovered(window) {
2113                                captured_mouse_down = pending_mouse_down.take();
2114                                window.refresh();
2115                            } else if pending_mouse_down.is_some() {
2116                                // Clear the pending mouse down event (without firing click handlers)
2117                                // if the hitbox is not being hovered.
2118                                // This avoids dragging elements that changed their position
2119                                // immediately after being clicked.
2120                                // See https://github.com/zed-industries/zed/issues/24600 for more details
2121                                pending_mouse_down.take();
2122                                window.refresh();
2123                            }
2124                        }
2125                        // Fire click handlers during the bubble phase.
2126                        DispatchPhase::Bubble => {
2127                            if let Some(mouse_down) = captured_mouse_down.take() {
2128                                let mouse_click = ClickEvent {
2129                                    down: mouse_down,
2130                                    up: event.clone(),
2131                                };
2132                                for listener in &click_listeners {
2133                                    listener(&mouse_click, window, cx);
2134                                }
2135                            }
2136                        }
2137                    }
2138                });
2139            }
2140
2141            if let Some(hover_listener) = self.hover_listener.take() {
2142                let hitbox = hitbox.clone();
2143                let was_hovered = element_state
2144                    .hover_state
2145                    .get_or_insert_with(Default::default)
2146                    .clone();
2147                let has_mouse_down = element_state
2148                    .pending_mouse_down
2149                    .get_or_insert_with(Default::default)
2150                    .clone();
2151
2152                window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2153                    if phase != DispatchPhase::Bubble {
2154                        return;
2155                    }
2156                    let is_hovered = has_mouse_down.borrow().is_none()
2157                        && !cx.has_active_drag()
2158                        && hitbox.is_hovered(window);
2159                    let mut was_hovered = was_hovered.borrow_mut();
2160
2161                    if is_hovered != *was_hovered {
2162                        *was_hovered = is_hovered;
2163                        drop(was_hovered);
2164
2165                        hover_listener(&is_hovered, window, cx);
2166                    }
2167                });
2168            }
2169
2170            if let Some(tooltip_builder) = self.tooltip_builder.take() {
2171                let active_tooltip = element_state
2172                    .active_tooltip
2173                    .get_or_insert_with(Default::default)
2174                    .clone();
2175                let pending_mouse_down = element_state
2176                    .pending_mouse_down
2177                    .get_or_insert_with(Default::default)
2178                    .clone();
2179
2180                let tooltip_is_hoverable = tooltip_builder.hoverable;
2181                let build_tooltip = Rc::new(move |window: &mut Window, cx: &mut App| {
2182                    Some(((tooltip_builder.build)(window, cx), tooltip_is_hoverable))
2183                });
2184                // Use bounds instead of testing hitbox since this is called during prepaint.
2185                let check_is_hovered_during_prepaint = Rc::new({
2186                    let pending_mouse_down = pending_mouse_down.clone();
2187                    let source_bounds = hitbox.bounds;
2188                    move |window: &Window| {
2189                        pending_mouse_down.borrow().is_none()
2190                            && source_bounds.contains(&window.mouse_position())
2191                    }
2192                });
2193                let check_is_hovered = Rc::new({
2194                    let hitbox = hitbox.clone();
2195                    move |window: &Window| {
2196                        pending_mouse_down.borrow().is_none() && hitbox.is_hovered(window)
2197                    }
2198                });
2199                register_tooltip_mouse_handlers(
2200                    &active_tooltip,
2201                    self.tooltip_id,
2202                    build_tooltip,
2203                    check_is_hovered,
2204                    check_is_hovered_during_prepaint,
2205                    window,
2206                );
2207            }
2208
2209            let active_state = element_state
2210                .clicked_state
2211                .get_or_insert_with(Default::default)
2212                .clone();
2213            if active_state.borrow().is_clicked() {
2214                window.on_mouse_event(move |_: &MouseUpEvent, phase, window, _cx| {
2215                    if phase == DispatchPhase::Capture {
2216                        *active_state.borrow_mut() = ElementClickedState::default();
2217                        window.refresh();
2218                    }
2219                });
2220            } else {
2221                let active_group_hitbox = self
2222                    .group_active_style
2223                    .as_ref()
2224                    .and_then(|group_active| GroupHitboxes::get(&group_active.group, cx));
2225                let hitbox = hitbox.clone();
2226                window.on_mouse_event(move |_: &MouseDownEvent, phase, window, _cx| {
2227                    if phase == DispatchPhase::Bubble && !window.default_prevented() {
2228                        let group_hovered = active_group_hitbox
2229                            .map_or(false, |group_hitbox_id| group_hitbox_id.is_hovered(window));
2230                        let element_hovered = hitbox.is_hovered(window);
2231                        if group_hovered || element_hovered {
2232                            *active_state.borrow_mut() = ElementClickedState {
2233                                group: group_hovered,
2234                                element: element_hovered,
2235                            };
2236                            window.refresh();
2237                        }
2238                    }
2239                });
2240            }
2241        }
2242    }
2243
2244    fn paint_keyboard_listeners(&mut self, window: &mut Window, _cx: &mut App) {
2245        let key_down_listeners = mem::take(&mut self.key_down_listeners);
2246        let key_up_listeners = mem::take(&mut self.key_up_listeners);
2247        let modifiers_changed_listeners = mem::take(&mut self.modifiers_changed_listeners);
2248        let action_listeners = mem::take(&mut self.action_listeners);
2249        if let Some(context) = self.key_context.clone() {
2250            window.set_key_context(context);
2251        }
2252
2253        for listener in key_down_listeners {
2254            window.on_key_event(move |event: &KeyDownEvent, phase, window, cx| {
2255                listener(event, phase, window, cx);
2256            })
2257        }
2258
2259        for listener in key_up_listeners {
2260            window.on_key_event(move |event: &KeyUpEvent, phase, window, cx| {
2261                listener(event, phase, window, cx);
2262            })
2263        }
2264
2265        for listener in modifiers_changed_listeners {
2266            window.on_modifiers_changed(move |event: &ModifiersChangedEvent, window, cx| {
2267                listener(event, window, cx);
2268            })
2269        }
2270
2271        for (action_type, listener) in action_listeners {
2272            window.on_action(action_type, listener)
2273        }
2274    }
2275
2276    fn paint_hover_group_handler(&self, window: &mut Window, cx: &mut App) {
2277        let group_hitbox = self
2278            .group_hover_style
2279            .as_ref()
2280            .and_then(|group_hover| GroupHitboxes::get(&group_hover.group, cx));
2281
2282        if let Some(group_hitbox) = group_hitbox {
2283            let was_hovered = group_hitbox.is_hovered(window);
2284            let current_view = window.current_view();
2285            window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2286                let hovered = group_hitbox.is_hovered(window);
2287                if phase == DispatchPhase::Capture && hovered != was_hovered {
2288                    cx.notify(current_view);
2289                }
2290            });
2291        }
2292    }
2293
2294    fn paint_scroll_listener(
2295        &self,
2296        hitbox: &Hitbox,
2297        style: &Style,
2298        window: &mut Window,
2299        _cx: &mut App,
2300    ) {
2301        if let Some(scroll_offset) = self.scroll_offset.clone() {
2302            let overflow = style.overflow;
2303            let allow_concurrent_scroll = style.allow_concurrent_scroll;
2304            let restrict_scroll_to_axis = style.restrict_scroll_to_axis;
2305            let line_height = window.line_height();
2306            let hitbox = hitbox.clone();
2307            let current_view = window.current_view();
2308            window.on_mouse_event(move |event: &ScrollWheelEvent, phase, window, cx| {
2309                if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
2310                    let mut scroll_offset = scroll_offset.borrow_mut();
2311                    let old_scroll_offset = *scroll_offset;
2312                    let delta = event.delta.pixel_delta(line_height);
2313
2314                    let mut delta_x = Pixels::ZERO;
2315                    if overflow.x == Overflow::Scroll {
2316                        if !delta.x.is_zero() {
2317                            delta_x = delta.x;
2318                        } else if !restrict_scroll_to_axis && overflow.y != Overflow::Scroll {
2319                            delta_x = delta.y;
2320                        }
2321                    }
2322                    let mut delta_y = Pixels::ZERO;
2323                    if overflow.y == Overflow::Scroll {
2324                        if !delta.y.is_zero() {
2325                            delta_y = delta.y;
2326                        } else if !restrict_scroll_to_axis && overflow.x != Overflow::Scroll {
2327                            delta_y = delta.x;
2328                        }
2329                    }
2330                    if !allow_concurrent_scroll && !delta_x.is_zero() && !delta_y.is_zero() {
2331                        if delta_x.abs() > delta_y.abs() {
2332                            delta_y = Pixels::ZERO;
2333                        } else {
2334                            delta_x = Pixels::ZERO;
2335                        }
2336                    }
2337                    scroll_offset.y += delta_y;
2338                    scroll_offset.x += delta_x;
2339                    if *scroll_offset != old_scroll_offset {
2340                        cx.notify(current_view);
2341                    }
2342                }
2343            });
2344        }
2345    }
2346
2347    /// Compute the visual style for this element, based on the current bounds and the element's state.
2348    pub fn compute_style(
2349        &self,
2350        global_id: Option<&GlobalElementId>,
2351        hitbox: Option<&Hitbox>,
2352        window: &mut Window,
2353        cx: &mut App,
2354    ) -> Style {
2355        window.with_optional_element_state(global_id, |element_state, window| {
2356            let mut element_state =
2357                element_state.map(|element_state| element_state.unwrap_or_default());
2358            let style = self.compute_style_internal(hitbox, element_state.as_mut(), window, cx);
2359            (style, element_state)
2360        })
2361    }
2362
2363    /// Called from internal methods that have already called with_element_state.
2364    fn compute_style_internal(
2365        &self,
2366        hitbox: Option<&Hitbox>,
2367        element_state: Option<&mut InteractiveElementState>,
2368        window: &mut Window,
2369        cx: &mut App,
2370    ) -> Style {
2371        let mut style = Style::default();
2372        style.refine(&self.base_style);
2373
2374        if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
2375            if let Some(in_focus_style) = self.in_focus_style.as_ref() {
2376                if focus_handle.within_focused(window, cx) {
2377                    style.refine(in_focus_style);
2378                }
2379            }
2380
2381            if let Some(focus_style) = self.focus_style.as_ref() {
2382                if focus_handle.is_focused(window) {
2383                    style.refine(focus_style);
2384                }
2385            }
2386        }
2387
2388        if let Some(hitbox) = hitbox {
2389            if !cx.has_active_drag() {
2390                if let Some(group_hover) = self.group_hover_style.as_ref() {
2391                    if let Some(group_hitbox_id) = GroupHitboxes::get(&group_hover.group, cx) {
2392                        if group_hitbox_id.is_hovered(window) {
2393                            style.refine(&group_hover.style);
2394                        }
2395                    }
2396                }
2397
2398                if let Some(hover_style) = self.hover_style.as_ref() {
2399                    if hitbox.is_hovered(window) {
2400                        style.refine(hover_style);
2401                    }
2402                }
2403            }
2404
2405            if let Some(drag) = cx.active_drag.take() {
2406                let mut can_drop = true;
2407                if let Some(can_drop_predicate) = &self.can_drop_predicate {
2408                    can_drop = can_drop_predicate(drag.value.as_ref(), window, cx);
2409                }
2410
2411                if can_drop {
2412                    for (state_type, group_drag_style) in &self.group_drag_over_styles {
2413                        if let Some(group_hitbox_id) =
2414                            GroupHitboxes::get(&group_drag_style.group, cx)
2415                        {
2416                            if *state_type == drag.value.as_ref().type_id()
2417                                && group_hitbox_id.is_hovered(window)
2418                            {
2419                                style.refine(&group_drag_style.style);
2420                            }
2421                        }
2422                    }
2423
2424                    for (state_type, build_drag_over_style) in &self.drag_over_styles {
2425                        if *state_type == drag.value.as_ref().type_id() && hitbox.is_hovered(window)
2426                        {
2427                            style.refine(&build_drag_over_style(drag.value.as_ref(), window, cx));
2428                        }
2429                    }
2430                }
2431
2432                style.mouse_cursor = drag.cursor_style;
2433                cx.active_drag = Some(drag);
2434            }
2435        }
2436
2437        if let Some(element_state) = element_state {
2438            let clicked_state = element_state
2439                .clicked_state
2440                .get_or_insert_with(Default::default)
2441                .borrow();
2442            if clicked_state.group {
2443                if let Some(group) = self.group_active_style.as_ref() {
2444                    style.refine(&group.style)
2445                }
2446            }
2447
2448            if let Some(active_style) = self.active_style.as_ref() {
2449                if clicked_state.element {
2450                    style.refine(active_style)
2451                }
2452            }
2453        }
2454
2455        style
2456    }
2457}
2458
2459/// The per-frame state of an interactive element. Used for tracking stateful interactions like clicks
2460/// and scroll offsets.
2461#[derive(Default)]
2462pub struct InteractiveElementState {
2463    pub(crate) focus_handle: Option<FocusHandle>,
2464    pub(crate) clicked_state: Option<Rc<RefCell<ElementClickedState>>>,
2465    pub(crate) hover_state: Option<Rc<RefCell<bool>>>,
2466    pub(crate) pending_mouse_down: Option<Rc<RefCell<Option<MouseDownEvent>>>>,
2467    pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
2468    pub(crate) active_tooltip: Option<Rc<RefCell<Option<ActiveTooltip>>>>,
2469}
2470
2471/// Whether or not the element or a group that contains it is clicked by the mouse.
2472#[derive(Copy, Clone, Default, Eq, PartialEq)]
2473pub struct ElementClickedState {
2474    /// True if this element's group has been clicked, false otherwise
2475    pub group: bool,
2476
2477    /// True if this element has been clicked, false otherwise
2478    pub element: bool,
2479}
2480
2481impl ElementClickedState {
2482    fn is_clicked(&self) -> bool {
2483        self.group || self.element
2484    }
2485}
2486
2487pub(crate) enum ActiveTooltip {
2488    /// Currently delaying before showing the tooltip.
2489    WaitingForShow { _task: Task<()> },
2490    /// Tooltip is visible, element was hovered or for hoverable tooltips, the tooltip was hovered.
2491    Visible {
2492        tooltip: AnyTooltip,
2493        is_hoverable: bool,
2494    },
2495    /// Tooltip is visible and hoverable, but the mouse is no longer hovering. Currently delaying
2496    /// before hiding it.
2497    WaitingForHide {
2498        tooltip: AnyTooltip,
2499        _task: Task<()>,
2500    },
2501}
2502
2503pub(crate) fn clear_active_tooltip(
2504    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2505    window: &mut Window,
2506) {
2507    match active_tooltip.borrow_mut().take() {
2508        None => {}
2509        Some(ActiveTooltip::WaitingForShow { .. }) => {}
2510        Some(ActiveTooltip::Visible { .. }) => window.refresh(),
2511        Some(ActiveTooltip::WaitingForHide { .. }) => window.refresh(),
2512    }
2513}
2514
2515pub(crate) fn clear_active_tooltip_if_not_hoverable(
2516    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2517    window: &mut Window,
2518) {
2519    let should_clear = match active_tooltip.borrow().as_ref() {
2520        None => false,
2521        Some(ActiveTooltip::WaitingForShow { .. }) => false,
2522        Some(ActiveTooltip::Visible { is_hoverable, .. }) => !is_hoverable,
2523        Some(ActiveTooltip::WaitingForHide { .. }) => false,
2524    };
2525    if should_clear {
2526        active_tooltip.borrow_mut().take();
2527        window.refresh();
2528    }
2529}
2530
2531pub(crate) fn set_tooltip_on_window(
2532    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2533    window: &mut Window,
2534) -> Option<TooltipId> {
2535    let tooltip = match active_tooltip.borrow().as_ref() {
2536        None => return None,
2537        Some(ActiveTooltip::WaitingForShow { .. }) => return None,
2538        Some(ActiveTooltip::Visible { tooltip, .. }) => tooltip.clone(),
2539        Some(ActiveTooltip::WaitingForHide { tooltip, .. }) => tooltip.clone(),
2540    };
2541    Some(window.set_tooltip(tooltip))
2542}
2543
2544pub(crate) fn register_tooltip_mouse_handlers(
2545    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2546    tooltip_id: Option<TooltipId>,
2547    build_tooltip: Rc<dyn Fn(&mut Window, &mut App) -> Option<(AnyView, bool)>>,
2548    check_is_hovered: Rc<dyn Fn(&Window) -> bool>,
2549    check_is_hovered_during_prepaint: Rc<dyn Fn(&Window) -> bool>,
2550    window: &mut Window,
2551) {
2552    window.on_mouse_event({
2553        let active_tooltip = active_tooltip.clone();
2554        let build_tooltip = build_tooltip.clone();
2555        let check_is_hovered = check_is_hovered.clone();
2556        move |_: &MouseMoveEvent, phase, window, cx| {
2557            handle_tooltip_mouse_move(
2558                &active_tooltip,
2559                &build_tooltip,
2560                &check_is_hovered,
2561                &check_is_hovered_during_prepaint,
2562                phase,
2563                window,
2564                cx,
2565            )
2566        }
2567    });
2568
2569    window.on_mouse_event({
2570        let active_tooltip = active_tooltip.clone();
2571        move |_: &MouseDownEvent, _phase, window: &mut Window, _cx| {
2572            if !tooltip_id.map_or(false, |tooltip_id| tooltip_id.is_hovered(window)) {
2573                clear_active_tooltip_if_not_hoverable(&active_tooltip, window);
2574            }
2575        }
2576    });
2577
2578    window.on_mouse_event({
2579        let active_tooltip = active_tooltip.clone();
2580        move |_: &ScrollWheelEvent, _phase, window: &mut Window, _cx| {
2581            if !tooltip_id.map_or(false, |tooltip_id| tooltip_id.is_hovered(window)) {
2582                clear_active_tooltip_if_not_hoverable(&active_tooltip, window);
2583            }
2584        }
2585    });
2586}
2587
2588/// Handles displaying tooltips when an element is hovered.
2589///
2590/// The mouse hovering logic also relies on being called from window prepaint in order to handle the
2591/// case where the element the tooltip is on is not rendered - in that case its mouse listeners are
2592/// also not registered. During window prepaint, the hitbox information is not available, so
2593/// `check_is_hovered_during_prepaint` is used which bases the check off of the absolute bounds of
2594/// the element.
2595///
2596/// TODO: There's a minor bug due to the use of absolute bounds while checking during prepaint - it
2597/// does not know if the hitbox is occluded. In the case where a tooltip gets displayed and then
2598/// gets occluded after display, it will stick around until the mouse exits the hover bounds.
2599fn handle_tooltip_mouse_move(
2600    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2601    build_tooltip: &Rc<dyn Fn(&mut Window, &mut App) -> Option<(AnyView, bool)>>,
2602    check_is_hovered: &Rc<dyn Fn(&Window) -> bool>,
2603    check_is_hovered_during_prepaint: &Rc<dyn Fn(&Window) -> bool>,
2604    phase: DispatchPhase,
2605    window: &mut Window,
2606    cx: &mut App,
2607) {
2608    // Separates logic for what mutation should occur from applying it, to avoid overlapping
2609    // RefCell borrows.
2610    enum Action {
2611        None,
2612        CancelShow,
2613        ScheduleShow,
2614    }
2615
2616    let action = match active_tooltip.borrow().as_ref() {
2617        None => {
2618            let is_hovered = check_is_hovered(window);
2619            if is_hovered && phase.bubble() {
2620                Action::ScheduleShow
2621            } else {
2622                Action::None
2623            }
2624        }
2625        Some(ActiveTooltip::WaitingForShow { .. }) => {
2626            let is_hovered = check_is_hovered(window);
2627            if is_hovered {
2628                Action::None
2629            } else {
2630                Action::CancelShow
2631            }
2632        }
2633        // These are handled in check_visible_and_update.
2634        Some(ActiveTooltip::Visible { .. }) | Some(ActiveTooltip::WaitingForHide { .. }) => {
2635            Action::None
2636        }
2637    };
2638
2639    match action {
2640        Action::None => {}
2641        Action::CancelShow => {
2642            // Cancel waiting to show tooltip when it is no longer hovered.
2643            active_tooltip.borrow_mut().take();
2644        }
2645        Action::ScheduleShow => {
2646            let delayed_show_task = window.spawn(cx, {
2647                let active_tooltip = active_tooltip.clone();
2648                let build_tooltip = build_tooltip.clone();
2649                let check_is_hovered_during_prepaint = check_is_hovered_during_prepaint.clone();
2650                async move |cx| {
2651                    cx.background_executor().timer(TOOLTIP_SHOW_DELAY).await;
2652                    cx.update(|window, cx| {
2653                        let new_tooltip =
2654                            build_tooltip(window, cx).map(|(view, tooltip_is_hoverable)| {
2655                                let active_tooltip = active_tooltip.clone();
2656                                ActiveTooltip::Visible {
2657                                    tooltip: AnyTooltip {
2658                                        view,
2659                                        mouse_position: window.mouse_position(),
2660                                        check_visible_and_update: Rc::new(
2661                                            move |tooltip_bounds, window, cx| {
2662                                                handle_tooltip_check_visible_and_update(
2663                                                    &active_tooltip,
2664                                                    tooltip_is_hoverable,
2665                                                    &check_is_hovered_during_prepaint,
2666                                                    tooltip_bounds,
2667                                                    window,
2668                                                    cx,
2669                                                )
2670                                            },
2671                                        ),
2672                                    },
2673                                    is_hoverable: tooltip_is_hoverable,
2674                                }
2675                            });
2676                        *active_tooltip.borrow_mut() = new_tooltip;
2677                        window.refresh();
2678                    })
2679                    .ok();
2680                }
2681            });
2682            active_tooltip
2683                .borrow_mut()
2684                .replace(ActiveTooltip::WaitingForShow {
2685                    _task: delayed_show_task,
2686                });
2687        }
2688    }
2689}
2690
2691/// Returns a callback which will be called by window prepaint to update tooltip visibility. The
2692/// purpose of doing this logic here instead of the mouse move handler is that the mouse move
2693/// handler won't get called when the element is not painted (e.g. via use of `visible_on_hover`).
2694fn handle_tooltip_check_visible_and_update(
2695    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2696    tooltip_is_hoverable: bool,
2697    check_is_hovered: &Rc<dyn Fn(&Window) -> bool>,
2698    tooltip_bounds: Bounds<Pixels>,
2699    window: &mut Window,
2700    cx: &mut App,
2701) -> bool {
2702    // Separates logic for what mutation should occur from applying it, to avoid overlapping RefCell
2703    // borrows.
2704    enum Action {
2705        None,
2706        Hide,
2707        ScheduleHide(AnyTooltip),
2708        CancelHide(AnyTooltip),
2709    }
2710
2711    let is_hovered = check_is_hovered(window)
2712        || (tooltip_is_hoverable && tooltip_bounds.contains(&window.mouse_position()));
2713    let action = match active_tooltip.borrow().as_ref() {
2714        Some(ActiveTooltip::Visible { tooltip, .. }) => {
2715            if is_hovered {
2716                Action::None
2717            } else {
2718                if tooltip_is_hoverable {
2719                    Action::ScheduleHide(tooltip.clone())
2720                } else {
2721                    Action::Hide
2722                }
2723            }
2724        }
2725        Some(ActiveTooltip::WaitingForHide { tooltip, .. }) => {
2726            if is_hovered {
2727                Action::CancelHide(tooltip.clone())
2728            } else {
2729                Action::None
2730            }
2731        }
2732        None | Some(ActiveTooltip::WaitingForShow { .. }) => Action::None,
2733    };
2734
2735    match action {
2736        Action::None => {}
2737        Action::Hide => clear_active_tooltip(&active_tooltip, window),
2738        Action::ScheduleHide(tooltip) => {
2739            let delayed_hide_task = window.spawn(cx, {
2740                let active_tooltip = active_tooltip.clone();
2741                async move |cx| {
2742                    cx.background_executor()
2743                        .timer(HOVERABLE_TOOLTIP_HIDE_DELAY)
2744                        .await;
2745                    if active_tooltip.borrow_mut().take().is_some() {
2746                        cx.update(|window, _cx| window.refresh()).ok();
2747                    }
2748                }
2749            });
2750            active_tooltip
2751                .borrow_mut()
2752                .replace(ActiveTooltip::WaitingForHide {
2753                    tooltip,
2754                    _task: delayed_hide_task,
2755                });
2756        }
2757        Action::CancelHide(tooltip) => {
2758            // Cancel waiting to hide tooltip when it becomes hovered.
2759            active_tooltip.borrow_mut().replace(ActiveTooltip::Visible {
2760                tooltip,
2761                is_hoverable: true,
2762            });
2763        }
2764    }
2765
2766    active_tooltip.borrow().is_some()
2767}
2768
2769#[derive(Default)]
2770pub(crate) struct GroupHitboxes(HashMap<SharedString, SmallVec<[HitboxId; 1]>>);
2771
2772impl Global for GroupHitboxes {}
2773
2774impl GroupHitboxes {
2775    pub fn get(name: &SharedString, cx: &mut App) -> Option<HitboxId> {
2776        cx.default_global::<Self>()
2777            .0
2778            .get(name)
2779            .and_then(|bounds_stack| bounds_stack.last())
2780            .cloned()
2781    }
2782
2783    pub fn push(name: SharedString, hitbox_id: HitboxId, cx: &mut App) {
2784        cx.default_global::<Self>()
2785            .0
2786            .entry(name)
2787            .or_default()
2788            .push(hitbox_id);
2789    }
2790
2791    pub fn pop(name: &SharedString, cx: &mut App) {
2792        cx.default_global::<Self>().0.get_mut(name).unwrap().pop();
2793    }
2794}
2795
2796/// A wrapper around an element that can store state, produced after assigning an ElementId.
2797pub struct Stateful<E> {
2798    pub(crate) element: E,
2799}
2800
2801impl<E> Styled for Stateful<E>
2802where
2803    E: Styled,
2804{
2805    fn style(&mut self) -> &mut StyleRefinement {
2806        self.element.style()
2807    }
2808}
2809
2810impl<E> StatefulInteractiveElement for Stateful<E>
2811where
2812    E: Element,
2813    Self: InteractiveElement,
2814{
2815}
2816
2817impl<E> InteractiveElement for Stateful<E>
2818where
2819    E: InteractiveElement,
2820{
2821    fn interactivity(&mut self) -> &mut Interactivity {
2822        self.element.interactivity()
2823    }
2824}
2825
2826impl<E> Element for Stateful<E>
2827where
2828    E: Element,
2829{
2830    type RequestLayoutState = E::RequestLayoutState;
2831    type PrepaintState = E::PrepaintState;
2832
2833    fn id(&self) -> Option<ElementId> {
2834        self.element.id()
2835    }
2836
2837    fn source_location(&self) -> Option<&'static core::panic::Location<'static>> {
2838        self.element.source_location()
2839    }
2840
2841    fn request_layout(
2842        &mut self,
2843        id: Option<&GlobalElementId>,
2844        inspector_id: Option<&InspectorElementId>,
2845        window: &mut Window,
2846        cx: &mut App,
2847    ) -> (LayoutId, Self::RequestLayoutState) {
2848        self.element.request_layout(id, inspector_id, window, cx)
2849    }
2850
2851    fn prepaint(
2852        &mut self,
2853        id: Option<&GlobalElementId>,
2854        inspector_id: Option<&InspectorElementId>,
2855        bounds: Bounds<Pixels>,
2856        state: &mut Self::RequestLayoutState,
2857        window: &mut Window,
2858        cx: &mut App,
2859    ) -> E::PrepaintState {
2860        self.element
2861            .prepaint(id, inspector_id, bounds, state, window, cx)
2862    }
2863
2864    fn paint(
2865        &mut self,
2866        id: Option<&GlobalElementId>,
2867        inspector_id: Option<&InspectorElementId>,
2868        bounds: Bounds<Pixels>,
2869        request_layout: &mut Self::RequestLayoutState,
2870        prepaint: &mut Self::PrepaintState,
2871        window: &mut Window,
2872        cx: &mut App,
2873    ) {
2874        self.element.paint(
2875            id,
2876            inspector_id,
2877            bounds,
2878            request_layout,
2879            prepaint,
2880            window,
2881            cx,
2882        );
2883    }
2884}
2885
2886impl<E> IntoElement for Stateful<E>
2887where
2888    E: Element,
2889{
2890    type Element = Self;
2891
2892    fn into_element(self) -> Self::Element {
2893        self
2894    }
2895}
2896
2897impl<E> ParentElement for Stateful<E>
2898where
2899    E: ParentElement,
2900{
2901    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
2902        self.element.extend(elements)
2903    }
2904}
2905
2906/// Represents an element that can be scrolled *to* in its parent element.
2907///
2908/// Contrary to [ScrollHandle::scroll_to_item], an anchored element does not have to be an immediate child of the parent.
2909#[derive(Clone)]
2910pub struct ScrollAnchor {
2911    handle: ScrollHandle,
2912    last_origin: Rc<RefCell<Point<Pixels>>>,
2913}
2914
2915impl ScrollAnchor {
2916    /// Creates a [ScrollAnchor] associated with a given [ScrollHandle].
2917    pub fn for_handle(handle: ScrollHandle) -> Self {
2918        Self {
2919            handle,
2920            last_origin: Default::default(),
2921        }
2922    }
2923    /// Request scroll to this item on the next frame.
2924    pub fn scroll_to(&self, window: &mut Window, _cx: &mut App) {
2925        let this = self.clone();
2926
2927        window.on_next_frame(move |_, _| {
2928            let viewport_bounds = this.handle.bounds();
2929            let self_bounds = *this.last_origin.borrow();
2930            this.handle.set_offset(viewport_bounds.origin - self_bounds);
2931        });
2932    }
2933}
2934
2935#[derive(Default, Debug)]
2936struct ScrollHandleState {
2937    offset: Rc<RefCell<Point<Pixels>>>,
2938    bounds: Bounds<Pixels>,
2939    padded_content_size: Size<Pixels>,
2940    child_bounds: Vec<Bounds<Pixels>>,
2941    scroll_to_bottom: bool,
2942    overflow: Point<Overflow>,
2943}
2944
2945/// A handle to the scrollable aspects of an element.
2946/// Used for accessing scroll state, like the current scroll offset,
2947/// and for mutating the scroll state, like scrolling to a specific child.
2948#[derive(Clone, Debug)]
2949pub struct ScrollHandle(Rc<RefCell<ScrollHandleState>>);
2950
2951impl Default for ScrollHandle {
2952    fn default() -> Self {
2953        Self::new()
2954    }
2955}
2956
2957impl ScrollHandle {
2958    /// Construct a new scroll handle.
2959    pub fn new() -> Self {
2960        Self(Rc::default())
2961    }
2962
2963    /// Get the current scroll offset.
2964    pub fn offset(&self) -> Point<Pixels> {
2965        *self.0.borrow().offset.borrow()
2966    }
2967
2968    /// Get the top child that's scrolled into view.
2969    pub fn top_item(&self) -> usize {
2970        let state = self.0.borrow();
2971        let top = state.bounds.top() - state.offset.borrow().y;
2972
2973        match state.child_bounds.binary_search_by(|bounds| {
2974            if top < bounds.top() {
2975                Ordering::Greater
2976            } else if top > bounds.bottom() {
2977                Ordering::Less
2978            } else {
2979                Ordering::Equal
2980            }
2981        }) {
2982            Ok(ix) => ix,
2983            Err(ix) => ix.min(state.child_bounds.len().saturating_sub(1)),
2984        }
2985    }
2986
2987    /// Return the bounds into which this child is painted
2988    pub fn bounds(&self) -> Bounds<Pixels> {
2989        self.0.borrow().bounds
2990    }
2991
2992    /// Set the bounds into which this child is painted
2993    pub(super) fn set_bounds(&self, bounds: Bounds<Pixels>) {
2994        self.0.borrow_mut().bounds = bounds;
2995    }
2996
2997    /// Get the bounds for a specific child.
2998    pub fn bounds_for_item(&self, ix: usize) -> Option<Bounds<Pixels>> {
2999        self.0.borrow().child_bounds.get(ix).cloned()
3000    }
3001
3002    /// Get the size of the content with padding of the container.
3003    pub fn padded_content_size(&self) -> Size<Pixels> {
3004        self.0.borrow().padded_content_size
3005    }
3006
3007    /// scroll_to_item scrolls the minimal amount to ensure that the child is
3008    /// fully visible
3009    pub fn scroll_to_item(&self, ix: usize) {
3010        let state = self.0.borrow();
3011
3012        let Some(bounds) = state.child_bounds.get(ix) else {
3013            return;
3014        };
3015
3016        let mut scroll_offset = state.offset.borrow_mut();
3017
3018        if state.overflow.y == Overflow::Scroll {
3019            if bounds.top() + scroll_offset.y < state.bounds.top() {
3020                scroll_offset.y = state.bounds.top() - bounds.top();
3021            } else if bounds.bottom() + scroll_offset.y > state.bounds.bottom() {
3022                scroll_offset.y = state.bounds.bottom() - bounds.bottom();
3023            }
3024        }
3025
3026        if state.overflow.x == Overflow::Scroll {
3027            if bounds.left() + scroll_offset.x < state.bounds.left() {
3028                scroll_offset.x = state.bounds.left() - bounds.left();
3029            } else if bounds.right() + scroll_offset.x > state.bounds.right() {
3030                scroll_offset.x = state.bounds.right() - bounds.right();
3031            }
3032        }
3033    }
3034
3035    /// Scrolls to the bottom.
3036    pub fn scroll_to_bottom(&self) {
3037        let mut state = self.0.borrow_mut();
3038        state.scroll_to_bottom = true;
3039    }
3040
3041    /// Set the offset explicitly. The offset is the distance from the top left of the
3042    /// parent container to the top left of the first child.
3043    /// As you scroll further down the offset becomes more negative.
3044    pub fn set_offset(&self, mut position: Point<Pixels>) {
3045        let state = self.0.borrow();
3046        *state.offset.borrow_mut() = position;
3047    }
3048
3049    /// Get the logical scroll top, based on a child index and a pixel offset.
3050    pub fn logical_scroll_top(&self) -> (usize, Pixels) {
3051        let ix = self.top_item();
3052        let state = self.0.borrow();
3053
3054        if let Some(child_bounds) = state.child_bounds.get(ix) {
3055            (
3056                ix,
3057                child_bounds.top() + state.offset.borrow().y - state.bounds.top(),
3058            )
3059        } else {
3060            (ix, px(0.))
3061        }
3062    }
3063
3064    /// Get the count of children for scrollable item.
3065    pub fn children_count(&self) -> usize {
3066        self.0.borrow().child_bounds.len()
3067    }
3068}