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
  18#[cfg(any(target_os = "linux", target_os = "macos"))]
  19use crate::PinchEvent;
  20use crate::{
  21    AbsoluteLength, Action, AnyDrag, AnyElement, AnyTooltip, AnyView, App, Bounds, ClickEvent,
  22    DispatchPhase, Display, Element, ElementId, Entity, FocusHandle, Global, GlobalElementId,
  23    Hitbox, HitboxBehavior, HitboxId, InspectorElementId, IntoElement, IsZero, KeyContext,
  24    KeyDownEvent, KeyUpEvent, KeyboardButton, KeyboardClickEvent, LayoutId, ModifiersChangedEvent,
  25    MouseButton, MouseClickEvent, MouseDownEvent, MouseMoveEvent, MousePressureEvent, MouseUpEvent,
  26    Overflow, ParentElement, Pixels, Point, Render, ScrollWheelEvent, SharedString, Size, Style,
  27    StyleRefinement, Styled, Task, TooltipId, Visibility, Window, WindowControlArea, point, px,
  28    size,
  29};
  30use collections::HashMap;
  31use gpui_util::ResultExt;
  32use refineable::Refineable;
  33use smallvec::SmallVec;
  34use stacksafe::{StackSafe, stacksafe};
  35use std::{
  36    any::{Any, TypeId},
  37    cell::RefCell,
  38    cmp::Ordering,
  39    fmt::Debug,
  40    marker::PhantomData,
  41    mem,
  42    rc::Rc,
  43    sync::Arc,
  44    time::Duration,
  45};
  46
  47use super::ImageCacheProvider;
  48
  49const DRAG_THRESHOLD: f64 = 2.;
  50const TOOLTIP_SHOW_DELAY: Duration = Duration::from_millis(500);
  51const HOVERABLE_TOOLTIP_HIDE_DELAY: Duration = Duration::from_millis(500);
  52
  53/// The styling information for a given group.
  54pub struct GroupStyle {
  55    /// The identifier for this group.
  56    pub group: SharedString,
  57
  58    /// The specific style refinement that this group would apply
  59    /// to its children.
  60    pub style: Box<StyleRefinement>,
  61}
  62
  63/// An event for when a drag is moving over this element, with the given state type.
  64pub struct DragMoveEvent<T> {
  65    /// The mouse move event that triggered this drag move event.
  66    pub event: MouseMoveEvent,
  67
  68    /// The bounds of this element.
  69    pub bounds: Bounds<Pixels>,
  70    drag: PhantomData<T>,
  71    dragged_item: Arc<dyn Any>,
  72}
  73
  74impl<T: 'static> DragMoveEvent<T> {
  75    /// Returns the drag state for this event.
  76    pub fn drag<'b>(&self, cx: &'b App) -> &'b T {
  77        cx.active_drag
  78            .as_ref()
  79            .and_then(|drag| drag.value.downcast_ref::<T>())
  80            .expect("DragMoveEvent is only valid when the stored active drag is of the same type.")
  81    }
  82
  83    /// An item that is about to be dropped.
  84    pub fn dragged_item(&self) -> &dyn Any {
  85        self.dragged_item.as_ref()
  86    }
  87}
  88
  89impl Interactivity {
  90    /// Create an `Interactivity`, capturing the caller location in debug mode.
  91    #[cfg(any(feature = "inspector", debug_assertions))]
  92    #[track_caller]
  93    pub fn new() -> Interactivity {
  94        Interactivity {
  95            source_location: Some(core::panic::Location::caller()),
  96            ..Default::default()
  97        }
  98    }
  99
 100    /// Create an `Interactivity`, capturing the caller location in debug mode.
 101    #[cfg(not(any(feature = "inspector", debug_assertions)))]
 102    pub fn new() -> Interactivity {
 103        Interactivity::default()
 104    }
 105
 106    /// Gets the source location of construction. Returns `None` when not in debug mode.
 107    pub fn source_location(&self) -> Option<&'static std::panic::Location<'static>> {
 108        #[cfg(any(feature = "inspector", debug_assertions))]
 109        {
 110            self.source_location
 111        }
 112
 113        #[cfg(not(any(feature = "inspector", debug_assertions)))]
 114        {
 115            None
 116        }
 117    }
 118
 119    /// Bind the given callback to the mouse down event for the given mouse button, during the bubble phase.
 120    /// The imperative API equivalent of [`InteractiveElement::on_mouse_down`].
 121    ///
 122    /// See [`Context::listener`](crate::Context::listener) to get access to the view state from this callback.
 123    pub fn on_mouse_down(
 124        &mut self,
 125        button: MouseButton,
 126        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 127    ) {
 128        self.mouse_down_listeners
 129            .push(Box::new(move |event, phase, hitbox, window, cx| {
 130                if phase == DispatchPhase::Bubble
 131                    && event.button == button
 132                    && hitbox.is_hovered(window)
 133                {
 134                    (listener)(event, window, cx)
 135                }
 136            }));
 137    }
 138
 139    /// Bind the given callback to the mouse down event for any button, during the capture phase.
 140    /// The imperative API equivalent of [`InteractiveElement::capture_any_mouse_down`].
 141    ///
 142    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 143    pub fn capture_any_mouse_down(
 144        &mut self,
 145        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 146    ) {
 147        self.mouse_down_listeners
 148            .push(Box::new(move |event, phase, hitbox, window, cx| {
 149                if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 150                    (listener)(event, window, cx)
 151                }
 152            }));
 153    }
 154
 155    /// Bind the given callback to the mouse down event for any button, during the bubble phase.
 156    /// The imperative API equivalent to [`InteractiveElement::on_any_mouse_down`].
 157    ///
 158    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 159    pub fn on_any_mouse_down(
 160        &mut self,
 161        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 162    ) {
 163        self.mouse_down_listeners
 164            .push(Box::new(move |event, phase, hitbox, window, cx| {
 165                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
 166                    (listener)(event, window, cx)
 167                }
 168            }));
 169    }
 170
 171    /// Bind the given callback to the mouse pressure event, during the bubble phase
 172    /// the imperative API equivalent to [`InteractiveElement::on_mouse_pressure`].
 173    ///
 174    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 175    pub fn on_mouse_pressure(
 176        &mut self,
 177        listener: impl Fn(&MousePressureEvent, &mut Window, &mut App) + 'static,
 178    ) {
 179        self.mouse_pressure_listeners
 180            .push(Box::new(move |event, phase, hitbox, window, cx| {
 181                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
 182                    (listener)(event, window, cx)
 183                }
 184            }));
 185    }
 186
 187    /// Bind the given callback to the mouse pressure event, during the capture phase
 188    /// the imperative API equivalent to [`InteractiveElement::on_mouse_pressure`].
 189    ///
 190    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 191    pub fn capture_mouse_pressure(
 192        &mut self,
 193        listener: impl Fn(&MousePressureEvent, &mut Window, &mut App) + 'static,
 194    ) {
 195        self.mouse_pressure_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 the given button, during the bubble phase.
 204    /// The imperative API equivalent to [`InteractiveElement::on_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_mouse_up(
 208        &mut self,
 209        button: MouseButton,
 210        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 211    ) {
 212        self.mouse_up_listeners
 213            .push(Box::new(move |event, phase, hitbox, window, cx| {
 214                if phase == DispatchPhase::Bubble
 215                    && event.button == button
 216                    && hitbox.is_hovered(window)
 217                {
 218                    (listener)(event, window, cx)
 219                }
 220            }));
 221    }
 222
 223    /// Bind the given callback to the mouse up event for any button, during the capture phase.
 224    /// The imperative API equivalent to [`InteractiveElement::capture_any_mouse_up`].
 225    ///
 226    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 227    pub fn capture_any_mouse_up(
 228        &mut self,
 229        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 230    ) {
 231        self.mouse_up_listeners
 232            .push(Box::new(move |event, phase, hitbox, window, cx| {
 233                if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 234                    (listener)(event, window, cx)
 235                }
 236            }));
 237    }
 238
 239    /// Bind the given callback to the mouse up event for any button, during the bubble phase.
 240    /// The imperative API equivalent to [`Interactivity::on_any_mouse_up`].
 241    ///
 242    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 243    pub fn on_any_mouse_up(
 244        &mut self,
 245        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 246    ) {
 247        self.mouse_up_listeners
 248            .push(Box::new(move |event, phase, hitbox, window, cx| {
 249                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
 250                    (listener)(event, window, cx)
 251                }
 252            }));
 253    }
 254
 255    /// Bind the given callback to the mouse down event, on any button, during the capture phase,
 256    /// when the mouse is outside of the bounds of this element.
 257    /// The imperative API equivalent to [`InteractiveElement::on_mouse_down_out`].
 258    ///
 259    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 260    pub fn on_mouse_down_out(
 261        &mut self,
 262        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 263    ) {
 264        self.mouse_down_listeners
 265            .push(Box::new(move |event, phase, hitbox, window, cx| {
 266                if phase == DispatchPhase::Capture && !hitbox.contains(&window.mouse_position()) {
 267                    (listener)(event, window, cx)
 268                }
 269            }));
 270    }
 271
 272    /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
 273    /// when the mouse is outside of the bounds of this element.
 274    /// The imperative API equivalent to [`InteractiveElement::on_mouse_up_out`].
 275    ///
 276    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 277    pub fn on_mouse_up_out(
 278        &mut self,
 279        button: MouseButton,
 280        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 281    ) {
 282        self.mouse_up_listeners
 283            .push(Box::new(move |event, phase, hitbox, window, cx| {
 284                if phase == DispatchPhase::Capture
 285                    && event.button == button
 286                    && !hitbox.is_hovered(window)
 287                {
 288                    (listener)(event, window, cx);
 289                }
 290            }));
 291    }
 292
 293    /// Bind the given callback to the mouse move event, during the bubble phase.
 294    /// The imperative API equivalent to [`InteractiveElement::on_mouse_move`].
 295    ///
 296    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 297    pub fn on_mouse_move(
 298        &mut self,
 299        listener: impl Fn(&MouseMoveEvent, &mut Window, &mut App) + 'static,
 300    ) {
 301        self.mouse_move_listeners
 302            .push(Box::new(move |event, phase, hitbox, window, cx| {
 303                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
 304                    (listener)(event, window, cx);
 305                }
 306            }));
 307    }
 308
 309    /// Bind the given callback to the mouse drag event of the given type. Note that this
 310    /// will be called for all move events, inside or outside of this element, as long as the
 311    /// drag was started with this element under the mouse. Useful for implementing draggable
 312    /// UIs that don't conform to a drag and drop style interaction, like resizing.
 313    /// The imperative API equivalent to [`InteractiveElement::on_drag_move`].
 314    ///
 315    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 316    pub fn on_drag_move<T>(
 317        &mut self,
 318        listener: impl Fn(&DragMoveEvent<T>, &mut Window, &mut App) + 'static,
 319    ) where
 320        T: 'static,
 321    {
 322        self.mouse_move_listeners
 323            .push(Box::new(move |event, phase, hitbox, window, cx| {
 324                if phase == DispatchPhase::Capture
 325                    && let Some(drag) = &cx.active_drag
 326                    && drag.value.as_ref().type_id() == TypeId::of::<T>()
 327                {
 328                    (listener)(
 329                        &DragMoveEvent {
 330                            event: event.clone(),
 331                            bounds: hitbox.bounds,
 332                            drag: PhantomData,
 333                            dragged_item: Arc::clone(&drag.value),
 334                        },
 335                        window,
 336                        cx,
 337                    );
 338                }
 339            }));
 340    }
 341
 342    /// Bind the given callback to scroll wheel events during the bubble phase.
 343    /// The imperative API equivalent to [`InteractiveElement::on_scroll_wheel`].
 344    ///
 345    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 346    pub fn on_scroll_wheel(
 347        &mut self,
 348        listener: impl Fn(&ScrollWheelEvent, &mut Window, &mut App) + 'static,
 349    ) {
 350        self.scroll_wheel_listeners
 351            .push(Box::new(move |event, phase, hitbox, window, cx| {
 352                if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
 353                    (listener)(event, window, cx);
 354                }
 355            }));
 356    }
 357
 358    /// Bind the given callback to pinch gesture events during the bubble phase.
 359    ///
 360    /// Note: This event is only available on macOS and Wayland (Linux).
 361    /// On Windows, pinch gestures are simulated as scroll wheel events with Ctrl held.
 362    ///
 363    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 364    #[cfg(any(target_os = "linux", target_os = "macos"))]
 365    pub fn on_pinch(&mut self, listener: impl Fn(&PinchEvent, &mut Window, &mut App) + 'static) {
 366        self.pinch_listeners
 367            .push(Box::new(move |event, phase, hitbox, window, cx| {
 368                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
 369                    (listener)(event, window, cx);
 370                }
 371            }));
 372    }
 373
 374    /// Bind the given callback to pinch gesture events during the capture phase.
 375    ///
 376    /// Note: This event is only available on macOS and Wayland (Linux).
 377    /// On Windows, pinch gestures are simulated as scroll wheel events with Ctrl held.
 378    ///
 379    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 380    #[cfg(any(target_os = "linux", target_os = "macos"))]
 381    pub fn capture_pinch(
 382        &mut self,
 383        listener: impl Fn(&PinchEvent, &mut Window, &mut App) + 'static,
 384    ) {
 385        self.pinch_listeners
 386            .push(Box::new(move |event, phase, _hitbox, window, cx| {
 387                if phase == DispatchPhase::Capture {
 388                    (listener)(event, window, cx);
 389                } else {
 390                    cx.propagate();
 391                }
 392            }));
 393    }
 394
 395    /// Bind the given callback to an action dispatch during the capture phase.
 396    /// The imperative API equivalent to [`InteractiveElement::capture_action`].
 397    ///
 398    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 399    pub fn capture_action<A: Action>(
 400        &mut self,
 401        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
 402    ) {
 403        self.action_listeners.push((
 404            TypeId::of::<A>(),
 405            Box::new(move |action, phase, window, cx| {
 406                let action = action.downcast_ref().unwrap();
 407                if phase == DispatchPhase::Capture {
 408                    (listener)(action, window, cx)
 409                } else {
 410                    cx.propagate();
 411                }
 412            }),
 413        ));
 414    }
 415
 416    /// Bind the given callback to an action dispatch during the bubble phase.
 417    /// The imperative API equivalent to [`InteractiveElement::on_action`].
 418    ///
 419    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 420    pub fn on_action<A: Action>(&mut self, listener: impl Fn(&A, &mut Window, &mut App) + 'static) {
 421        self.action_listeners.push((
 422            TypeId::of::<A>(),
 423            Box::new(move |action, phase, window, cx| {
 424                let action = action.downcast_ref().unwrap();
 425                if phase == DispatchPhase::Bubble {
 426                    (listener)(action, window, cx)
 427                }
 428            }),
 429        ));
 430    }
 431
 432    /// Bind the given callback to an action dispatch, based on a dynamic action parameter
 433    /// instead of a type parameter. Useful for component libraries that want to expose
 434    /// action bindings to their users.
 435    /// The imperative API equivalent to [`InteractiveElement::on_boxed_action`].
 436    ///
 437    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 438    pub fn on_boxed_action(
 439        &mut self,
 440        action: &dyn Action,
 441        listener: impl Fn(&dyn Action, &mut Window, &mut App) + 'static,
 442    ) {
 443        let action = action.boxed_clone();
 444        self.action_listeners.push((
 445            (*action).type_id(),
 446            Box::new(move |_, phase, window, cx| {
 447                if phase == DispatchPhase::Bubble {
 448                    (listener)(&*action, window, cx)
 449                }
 450            }),
 451        ));
 452    }
 453
 454    /// Bind the given callback to key down events during the bubble phase.
 455    /// The imperative API equivalent to [`InteractiveElement::on_key_down`].
 456    ///
 457    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 458    pub fn on_key_down(
 459        &mut self,
 460        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
 461    ) {
 462        self.key_down_listeners
 463            .push(Box::new(move |event, phase, window, cx| {
 464                if phase == DispatchPhase::Bubble {
 465                    (listener)(event, window, cx)
 466                }
 467            }));
 468    }
 469
 470    /// Bind the given callback to key down events during the capture phase.
 471    /// The imperative API equivalent to [`InteractiveElement::capture_key_down`].
 472    ///
 473    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 474    pub fn capture_key_down(
 475        &mut self,
 476        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
 477    ) {
 478        self.key_down_listeners
 479            .push(Box::new(move |event, phase, window, cx| {
 480                if phase == DispatchPhase::Capture {
 481                    listener(event, window, cx)
 482                }
 483            }));
 484    }
 485
 486    /// Bind the given callback to key up events during the bubble phase.
 487    /// The imperative API equivalent to [`InteractiveElement::on_key_up`].
 488    ///
 489    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 490    pub fn on_key_up(&mut self, listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static) {
 491        self.key_up_listeners
 492            .push(Box::new(move |event, phase, window, cx| {
 493                if phase == DispatchPhase::Bubble {
 494                    listener(event, window, cx)
 495                }
 496            }));
 497    }
 498
 499    /// Bind the given callback to key up events during the capture phase.
 500    /// The imperative API equivalent to [`InteractiveElement::on_key_up`].
 501    ///
 502    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 503    pub fn capture_key_up(
 504        &mut self,
 505        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
 506    ) {
 507        self.key_up_listeners
 508            .push(Box::new(move |event, phase, window, cx| {
 509                if phase == DispatchPhase::Capture {
 510                    listener(event, window, cx)
 511                }
 512            }));
 513    }
 514
 515    /// Bind the given callback to modifiers changing events.
 516    /// The imperative API equivalent to [`InteractiveElement::on_modifiers_changed`].
 517    ///
 518    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 519    pub fn on_modifiers_changed(
 520        &mut self,
 521        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
 522    ) {
 523        self.modifiers_changed_listeners
 524            .push(Box::new(move |event, window, cx| {
 525                listener(event, window, cx)
 526            }));
 527    }
 528
 529    /// Bind the given callback to drop events of the given type, whether or not the drag started on this element.
 530    /// The imperative API equivalent to [`InteractiveElement::on_drop`].
 531    ///
 532    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 533    pub fn on_drop<T: 'static>(&mut self, listener: impl Fn(&T, &mut Window, &mut App) + 'static) {
 534        self.drop_listeners.push((
 535            TypeId::of::<T>(),
 536            Box::new(move |dragged_value, window, cx| {
 537                listener(dragged_value.downcast_ref().unwrap(), window, cx);
 538            }),
 539        ));
 540    }
 541
 542    /// Use the given predicate to determine whether or not a drop event should be dispatched to this element.
 543    /// The imperative API equivalent to [`InteractiveElement::can_drop`].
 544    pub fn can_drop(
 545        &mut self,
 546        predicate: impl Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static,
 547    ) {
 548        self.can_drop_predicate = Some(Box::new(predicate));
 549    }
 550
 551    /// Bind the given callback to click events of this element.
 552    /// The imperative API equivalent to [`StatefulInteractiveElement::on_click`].
 553    ///
 554    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 555    pub fn on_click(&mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static)
 556    where
 557        Self: Sized,
 558    {
 559        self.click_listeners.push(Rc::new(move |event, window, cx| {
 560            listener(event, window, cx)
 561        }));
 562    }
 563
 564    /// Bind the given callback to non-primary click events of this element.
 565    /// The imperative API equivalent to [`StatefulInteractiveElement::on_aux_click`].
 566    ///
 567    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 568    pub fn on_aux_click(&mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static)
 569    where
 570        Self: Sized,
 571    {
 572        self.aux_click_listeners
 573            .push(Rc::new(move |event, window, cx| {
 574                listener(event, window, cx)
 575            }));
 576    }
 577
 578    /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
 579    /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
 580    /// the [`Self::on_drag_move`] API.
 581    /// The imperative API equivalent to [`StatefulInteractiveElement::on_drag`].
 582    ///
 583    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 584    pub fn on_drag<T, W>(
 585        &mut self,
 586        value: T,
 587        constructor: impl Fn(&T, Point<Pixels>, &mut Window, &mut App) -> Entity<W> + 'static,
 588    ) where
 589        Self: Sized,
 590        T: 'static,
 591        W: 'static + Render,
 592    {
 593        debug_assert!(
 594            self.drag_listener.is_none(),
 595            "calling on_drag more than once on the same element is not supported"
 596        );
 597        self.drag_listener = Some((
 598            Arc::new(value),
 599            Box::new(move |value, offset, window, cx| {
 600                constructor(value.downcast_ref().unwrap(), offset, window, cx).into()
 601            }),
 602        ));
 603    }
 604
 605    /// Bind the given callback on the hover start and end events of this element. Note that the boolean
 606    /// passed to the callback is true when the hover starts and false when it ends.
 607    /// The imperative API equivalent to [`StatefulInteractiveElement::on_hover`].
 608    ///
 609    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 610    pub fn on_hover(&mut self, listener: impl Fn(&bool, &mut Window, &mut App) + 'static)
 611    where
 612        Self: Sized,
 613    {
 614        debug_assert!(
 615            self.hover_listener.is_none(),
 616            "calling on_hover more than once on the same element is not supported"
 617        );
 618        self.hover_listener = Some(Box::new(listener));
 619    }
 620
 621    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
 622    /// The imperative API equivalent to [`StatefulInteractiveElement::tooltip`].
 623    pub fn tooltip(&mut self, build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static)
 624    where
 625        Self: Sized,
 626    {
 627        debug_assert!(
 628            self.tooltip_builder.is_none(),
 629            "calling tooltip more than once on the same element is not supported"
 630        );
 631        self.tooltip_builder = Some(TooltipBuilder {
 632            build: Rc::new(build_tooltip),
 633            hoverable: false,
 634        });
 635    }
 636
 637    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
 638    /// The tooltip itself is also hoverable and won't disappear when the user moves the mouse into
 639    /// the tooltip. The imperative API equivalent to [`StatefulInteractiveElement::hoverable_tooltip`].
 640    pub fn hoverable_tooltip(
 641        &mut self,
 642        build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static,
 643    ) where
 644        Self: Sized,
 645    {
 646        debug_assert!(
 647            self.tooltip_builder.is_none(),
 648            "calling tooltip more than once on the same element is not supported"
 649        );
 650        self.tooltip_builder = Some(TooltipBuilder {
 651            build: Rc::new(build_tooltip),
 652            hoverable: true,
 653        });
 654    }
 655
 656    /// Block the mouse from all interactions with elements behind this element's hitbox. Typically
 657    /// `block_mouse_except_scroll` should be preferred.
 658    ///
 659    /// The imperative API equivalent to [`InteractiveElement::occlude`]
 660    pub fn occlude_mouse(&mut self) {
 661        self.hitbox_behavior = HitboxBehavior::BlockMouse;
 662    }
 663
 664    /// Set the bounds of this element as a window control area for the platform window.
 665    /// The imperative API equivalent to [`InteractiveElement::window_control_area`]
 666    pub fn window_control_area(&mut self, area: WindowControlArea) {
 667        self.window_control = Some(area);
 668    }
 669
 670    /// Block non-scroll mouse interactions with elements behind this element's hitbox.
 671    /// The imperative API equivalent to [`InteractiveElement::block_mouse_except_scroll`].
 672    ///
 673    /// See [`Hitbox::is_hovered`] for details.
 674    pub fn block_mouse_except_scroll(&mut self) {
 675        self.hitbox_behavior = HitboxBehavior::BlockMouseExceptScroll;
 676    }
 677
 678    #[cfg(any(target_os = "linux", target_os = "macos"))]
 679    fn has_pinch_listeners(&self) -> bool {
 680        !self.pinch_listeners.is_empty()
 681    }
 682
 683    #[cfg(not(any(target_os = "linux", target_os = "macos")))]
 684    fn has_pinch_listeners(&self) -> bool {
 685        false
 686    }
 687}
 688
 689/// A trait for elements that want to use the standard GPUI event handlers that don't
 690/// require any state.
 691pub trait InteractiveElement: Sized {
 692    /// Retrieve the interactivity state associated with this element
 693    fn interactivity(&mut self) -> &mut Interactivity;
 694
 695    /// Assign this element to a group of elements that can be styled together
 696    fn group(mut self, group: impl Into<SharedString>) -> Self {
 697        self.interactivity().group = Some(group.into());
 698        self
 699    }
 700
 701    /// Assign this element an ID, so that it can be used with interactivity
 702    fn id(mut self, id: impl Into<ElementId>) -> Stateful<Self> {
 703        self.interactivity().element_id = Some(id.into());
 704
 705        Stateful { element: self }
 706    }
 707
 708    /// Track the focus state of the given focus handle on this element.
 709    /// If the focus handle is focused by the application, this element will
 710    /// apply its focused styles.
 711    fn track_focus(mut self, focus_handle: &FocusHandle) -> Self {
 712        self.interactivity().focusable = true;
 713        self.interactivity().tracked_focus_handle = Some(focus_handle.clone());
 714        self
 715    }
 716
 717    /// Set whether this element is a tab stop.
 718    ///
 719    /// When false, the element remains in tab-index order but cannot be reached via keyboard navigation.
 720    /// Useful for container elements: focus the container, then call `window.focus_next(cx)` to focus
 721    /// the first tab stop inside it while having the container element itself be unreachable via the keyboard.
 722    /// Should only be used with `tab_index`.
 723    fn tab_stop(mut self, tab_stop: bool) -> Self {
 724        self.interactivity().tab_stop = tab_stop;
 725        self
 726    }
 727
 728    /// Set index of the tab stop order, and set this node as a tab stop.
 729    /// This will default the element to being a tab stop. See [`Self::tab_stop`] for more information.
 730    /// This should only be used in conjunction with `tab_group`
 731    /// in order to not interfere with the tab index of other elements.
 732    fn tab_index(mut self, index: isize) -> Self {
 733        self.interactivity().focusable = true;
 734        self.interactivity().tab_index = Some(index);
 735        self.interactivity().tab_stop = true;
 736        self
 737    }
 738
 739    /// Designate this div as a "tab group". Tab groups have their own location in the tab-index order,
 740    /// but for children of the tab group, the tab index is reset to 0. This can be useful for swapping
 741    /// the order of tab stops within the group, without having to renumber all the tab stops in the whole
 742    /// application.
 743    fn tab_group(mut self) -> Self {
 744        self.interactivity().tab_group = true;
 745        if self.interactivity().tab_index.is_none() {
 746            self.interactivity().tab_index = Some(0);
 747        }
 748        self
 749    }
 750
 751    /// Set the keymap context for this element. This will be used to determine
 752    /// which action to dispatch from the keymap.
 753    fn key_context<C, E>(mut self, key_context: C) -> Self
 754    where
 755        C: TryInto<KeyContext, Error = E>,
 756        E: Debug,
 757    {
 758        if let Some(key_context) = key_context.try_into().log_err() {
 759            self.interactivity().key_context = Some(key_context);
 760        }
 761        self
 762    }
 763
 764    /// Apply the given style to this element when the mouse hovers over it
 765    fn hover(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self {
 766        debug_assert!(
 767            self.interactivity().hover_style.is_none(),
 768            "hover style already set"
 769        );
 770        self.interactivity().hover_style = Some(Box::new(f(StyleRefinement::default())));
 771        self
 772    }
 773
 774    /// Apply the given style to this element when the mouse hovers over a group member
 775    fn group_hover(
 776        mut self,
 777        group_name: impl Into<SharedString>,
 778        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
 779    ) -> Self {
 780        self.interactivity().group_hover_style = Some(GroupStyle {
 781            group: group_name.into(),
 782            style: Box::new(f(StyleRefinement::default())),
 783        });
 784        self
 785    }
 786
 787    /// Bind the given callback to the mouse down event for the given mouse button.
 788    /// The fluent API equivalent to [`Interactivity::on_mouse_down`].
 789    ///
 790    /// See [`Context::listener`](crate::Context::listener) to get access to the view state from this callback.
 791    fn on_mouse_down(
 792        mut self,
 793        button: MouseButton,
 794        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 795    ) -> Self {
 796        self.interactivity().on_mouse_down(button, listener);
 797        self
 798    }
 799
 800    #[cfg(any(test, feature = "test-support"))]
 801    /// Set a key that can be used to look up this element's bounds
 802    /// in the [`crate::VisualTestContext::debug_bounds`] map
 803    /// This is a noop in release builds
 804    fn debug_selector(mut self, f: impl FnOnce() -> String) -> Self {
 805        self.interactivity().debug_selector = Some(f());
 806        self
 807    }
 808
 809    #[cfg(not(any(test, feature = "test-support")))]
 810    /// Set a key that can be used to look up this element's bounds
 811    /// in the [`crate::VisualTestContext::debug_bounds`] map
 812    /// This is a noop in release builds
 813    #[inline]
 814    fn debug_selector(self, _: impl FnOnce() -> String) -> Self {
 815        self
 816    }
 817
 818    /// Bind the given callback to the mouse down event for any button, during the capture phase.
 819    /// The fluent API equivalent to [`Interactivity::capture_any_mouse_down`].
 820    ///
 821    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 822    fn capture_any_mouse_down(
 823        mut self,
 824        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 825    ) -> Self {
 826        self.interactivity().capture_any_mouse_down(listener);
 827        self
 828    }
 829
 830    /// Bind the given callback to the mouse down event for any button, during the capture phase.
 831    /// The fluent API equivalent to [`Interactivity::on_any_mouse_down`].
 832    ///
 833    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 834    fn on_any_mouse_down(
 835        mut self,
 836        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 837    ) -> Self {
 838        self.interactivity().on_any_mouse_down(listener);
 839        self
 840    }
 841
 842    /// Bind the given callback to the mouse up event for the given button, during the bubble phase.
 843    /// The fluent API equivalent to [`Interactivity::on_mouse_up`].
 844    ///
 845    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 846    fn on_mouse_up(
 847        mut self,
 848        button: MouseButton,
 849        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 850    ) -> Self {
 851        self.interactivity().on_mouse_up(button, listener);
 852        self
 853    }
 854
 855    /// Bind the given callback to the mouse up event for any button, during the capture phase.
 856    /// The fluent API equivalent to [`Interactivity::capture_any_mouse_up`].
 857    ///
 858    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 859    fn capture_any_mouse_up(
 860        mut self,
 861        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 862    ) -> Self {
 863        self.interactivity().capture_any_mouse_up(listener);
 864        self
 865    }
 866
 867    /// Bind the given callback to the mouse pressure event, during the bubble phase
 868    /// the fluent API equivalent to [`Interactivity::on_mouse_pressure`]
 869    ///
 870    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 871    fn on_mouse_pressure(
 872        mut self,
 873        listener: impl Fn(&MousePressureEvent, &mut Window, &mut App) + 'static,
 874    ) -> Self {
 875        self.interactivity().on_mouse_pressure(listener);
 876        self
 877    }
 878
 879    /// Bind the given callback to the mouse pressure event, during the capture phase
 880    /// the fluent API equivalent to [`Interactivity::on_mouse_pressure`]
 881    ///
 882    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 883    fn capture_mouse_pressure(
 884        mut self,
 885        listener: impl Fn(&MousePressureEvent, &mut Window, &mut App) + 'static,
 886    ) -> Self {
 887        self.interactivity().capture_mouse_pressure(listener);
 888        self
 889    }
 890
 891    /// Bind the given callback to the mouse down event, on any button, during the capture phase,
 892    /// when the mouse is outside of the bounds of this element.
 893    /// The fluent API equivalent to [`Interactivity::on_mouse_down_out`].
 894    ///
 895    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 896    fn on_mouse_down_out(
 897        mut self,
 898        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 899    ) -> Self {
 900        self.interactivity().on_mouse_down_out(listener);
 901        self
 902    }
 903
 904    /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
 905    /// when the mouse is outside of the bounds of this element.
 906    /// The fluent API equivalent to [`Interactivity::on_mouse_up_out`].
 907    ///
 908    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 909    fn on_mouse_up_out(
 910        mut self,
 911        button: MouseButton,
 912        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 913    ) -> Self {
 914        self.interactivity().on_mouse_up_out(button, listener);
 915        self
 916    }
 917
 918    /// Bind the given callback to the mouse move event, during the bubble phase.
 919    /// The fluent API equivalent to [`Interactivity::on_mouse_move`].
 920    ///
 921    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 922    fn on_mouse_move(
 923        mut self,
 924        listener: impl Fn(&MouseMoveEvent, &mut Window, &mut App) + 'static,
 925    ) -> Self {
 926        self.interactivity().on_mouse_move(listener);
 927        self
 928    }
 929
 930    /// Bind the given callback to the mouse drag event of the given type. Note that this
 931    /// will be called for all move events, inside or outside of this element, as long as the
 932    /// drag was started with this element under the mouse. Useful for implementing draggable
 933    /// UIs that don't conform to a drag and drop style interaction, like resizing.
 934    /// The fluent API equivalent to [`Interactivity::on_drag_move`].
 935    ///
 936    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 937    fn on_drag_move<T: 'static>(
 938        mut self,
 939        listener: impl Fn(&DragMoveEvent<T>, &mut Window, &mut App) + 'static,
 940    ) -> Self {
 941        self.interactivity().on_drag_move(listener);
 942        self
 943    }
 944
 945    /// Bind the given callback to scroll wheel events during the bubble phase.
 946    /// The fluent API equivalent to [`Interactivity::on_scroll_wheel`].
 947    ///
 948    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 949    fn on_scroll_wheel(
 950        mut self,
 951        listener: impl Fn(&ScrollWheelEvent, &mut Window, &mut App) + 'static,
 952    ) -> Self {
 953        self.interactivity().on_scroll_wheel(listener);
 954        self
 955    }
 956
 957    /// Bind the given callback to pinch gesture events during the bubble phase.
 958    /// The fluent API equivalent to [`Interactivity::on_pinch`].
 959    ///
 960    /// Note: This event is only available on macOS and Wayland (Linux).
 961    /// On Windows, pinch gestures are simulated as scroll wheel events with Ctrl held.
 962    ///
 963    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 964    #[cfg(any(target_os = "linux", target_os = "macos"))]
 965    fn on_pinch(mut self, listener: impl Fn(&PinchEvent, &mut Window, &mut App) + 'static) -> Self {
 966        self.interactivity().on_pinch(listener);
 967        self
 968    }
 969
 970    /// Bind the given callback to pinch gesture events during the capture phase.
 971    /// The fluent API equivalent to [`Interactivity::capture_pinch`].
 972    ///
 973    /// Note: This event is only available on macOS and Wayland (Linux).
 974    /// On Windows, pinch gestures are simulated as scroll wheel events with Ctrl held.
 975    ///
 976    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 977    #[cfg(any(target_os = "linux", target_os = "macos"))]
 978    fn capture_pinch(
 979        mut self,
 980        listener: impl Fn(&PinchEvent, &mut Window, &mut App) + 'static,
 981    ) -> Self {
 982        self.interactivity().capture_pinch(listener);
 983        self
 984    }
 985    /// Capture the given action, before normal action dispatch can fire.
 986    /// The fluent API equivalent to [`Interactivity::capture_action`].
 987    ///
 988    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 989    fn capture_action<A: Action>(
 990        mut self,
 991        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
 992    ) -> Self {
 993        self.interactivity().capture_action(listener);
 994        self
 995    }
 996
 997    /// Bind the given callback to an action dispatch during the bubble phase.
 998    /// The fluent API equivalent to [`Interactivity::on_action`].
 999    ///
1000    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1001    fn on_action<A: Action>(
1002        mut self,
1003        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
1004    ) -> Self {
1005        self.interactivity().on_action(listener);
1006        self
1007    }
1008
1009    /// Bind the given callback to an action dispatch, based on a dynamic action parameter
1010    /// instead of a type parameter. Useful for component libraries that want to expose
1011    /// action bindings to their users.
1012    /// The fluent API equivalent to [`Interactivity::on_boxed_action`].
1013    ///
1014    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1015    fn on_boxed_action(
1016        mut self,
1017        action: &dyn Action,
1018        listener: impl Fn(&dyn Action, &mut Window, &mut App) + 'static,
1019    ) -> Self {
1020        self.interactivity().on_boxed_action(action, listener);
1021        self
1022    }
1023
1024    /// Bind the given callback to key down events during the bubble phase.
1025    /// The fluent API equivalent to [`Interactivity::on_key_down`].
1026    ///
1027    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1028    fn on_key_down(
1029        mut self,
1030        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
1031    ) -> Self {
1032        self.interactivity().on_key_down(listener);
1033        self
1034    }
1035
1036    /// Bind the given callback to key down events during the capture phase.
1037    /// The fluent API equivalent to [`Interactivity::capture_key_down`].
1038    ///
1039    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1040    fn capture_key_down(
1041        mut self,
1042        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
1043    ) -> Self {
1044        self.interactivity().capture_key_down(listener);
1045        self
1046    }
1047
1048    /// Bind the given callback to key up events during the bubble phase.
1049    /// The fluent API equivalent to [`Interactivity::on_key_up`].
1050    ///
1051    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1052    fn on_key_up(
1053        mut self,
1054        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
1055    ) -> Self {
1056        self.interactivity().on_key_up(listener);
1057        self
1058    }
1059
1060    /// Bind the given callback to key up events during the capture phase.
1061    /// The fluent API equivalent to [`Interactivity::capture_key_up`].
1062    ///
1063    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1064    fn capture_key_up(
1065        mut self,
1066        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
1067    ) -> Self {
1068        self.interactivity().capture_key_up(listener);
1069        self
1070    }
1071
1072    /// Bind the given callback to modifiers changing events.
1073    /// The fluent API equivalent to [`Interactivity::on_modifiers_changed`].
1074    ///
1075    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1076    fn on_modifiers_changed(
1077        mut self,
1078        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
1079    ) -> Self {
1080        self.interactivity().on_modifiers_changed(listener);
1081        self
1082    }
1083
1084    /// Apply the given style when the given data type is dragged over this element
1085    fn drag_over<S: 'static>(
1086        mut self,
1087        f: impl 'static + Fn(StyleRefinement, &S, &mut Window, &mut App) -> StyleRefinement,
1088    ) -> Self {
1089        self.interactivity().drag_over_styles.push((
1090            TypeId::of::<S>(),
1091            Box::new(move |currently_dragged: &dyn Any, window, cx| {
1092                f(
1093                    StyleRefinement::default(),
1094                    currently_dragged.downcast_ref::<S>().unwrap(),
1095                    window,
1096                    cx,
1097                )
1098            }),
1099        ));
1100        self
1101    }
1102
1103    /// Apply the given style when the given data type is dragged over this element's group
1104    fn group_drag_over<S: 'static>(
1105        mut self,
1106        group_name: impl Into<SharedString>,
1107        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
1108    ) -> Self {
1109        self.interactivity().group_drag_over_styles.push((
1110            TypeId::of::<S>(),
1111            GroupStyle {
1112                group: group_name.into(),
1113                style: Box::new(f(StyleRefinement::default())),
1114            },
1115        ));
1116        self
1117    }
1118
1119    /// Bind the given callback to drop events of the given type, whether or not the drag started on this element.
1120    /// The fluent API equivalent to [`Interactivity::on_drop`].
1121    ///
1122    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1123    fn on_drop<T: 'static>(
1124        mut self,
1125        listener: impl Fn(&T, &mut Window, &mut App) + 'static,
1126    ) -> Self {
1127        self.interactivity().on_drop(listener);
1128        self
1129    }
1130
1131    /// Use the given predicate to determine whether or not a drop event should be dispatched to this element.
1132    /// The fluent API equivalent to [`Interactivity::can_drop`].
1133    fn can_drop(
1134        mut self,
1135        predicate: impl Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static,
1136    ) -> Self {
1137        self.interactivity().can_drop(predicate);
1138        self
1139    }
1140
1141    /// Block the mouse from all interactions with elements behind this element's hitbox. Typically
1142    /// `block_mouse_except_scroll` should be preferred.
1143    /// The fluent API equivalent to [`Interactivity::occlude_mouse`].
1144    fn occlude(mut self) -> Self {
1145        self.interactivity().occlude_mouse();
1146        self
1147    }
1148
1149    /// Set the bounds of this element as a window control area for the platform window.
1150    /// The fluent API equivalent to [`Interactivity::window_control_area`].
1151    fn window_control_area(mut self, area: WindowControlArea) -> Self {
1152        self.interactivity().window_control_area(area);
1153        self
1154    }
1155
1156    /// Block non-scroll mouse interactions with elements behind this element's hitbox.
1157    /// The fluent API equivalent to [`Interactivity::block_mouse_except_scroll`].
1158    ///
1159    /// See [`Hitbox::is_hovered`] for details.
1160    fn block_mouse_except_scroll(mut self) -> Self {
1161        self.interactivity().block_mouse_except_scroll();
1162        self
1163    }
1164
1165    /// Set the given styles to be applied when this element, specifically, is focused.
1166    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
1167    fn focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1168    where
1169        Self: Sized,
1170    {
1171        self.interactivity().focus_style = Some(Box::new(f(StyleRefinement::default())));
1172        self
1173    }
1174
1175    /// Set the given styles to be applied when this element is inside another element that is focused.
1176    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
1177    fn in_focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1178    where
1179        Self: Sized,
1180    {
1181        self.interactivity().in_focus_style = Some(Box::new(f(StyleRefinement::default())));
1182        self
1183    }
1184
1185    /// Set the given styles to be applied when this element is focused via keyboard navigation.
1186    /// This is similar to CSS's `:focus-visible` pseudo-class - it only applies when the element
1187    /// is focused AND the user is navigating via keyboard (not mouse clicks).
1188    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
1189    fn focus_visible(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1190    where
1191        Self: Sized,
1192    {
1193        self.interactivity().focus_visible_style = Some(Box::new(f(StyleRefinement::default())));
1194        self
1195    }
1196}
1197
1198/// A trait for elements that want to use the standard GPUI interactivity features
1199/// that require state.
1200pub trait StatefulInteractiveElement: InteractiveElement {
1201    /// Set this element to focusable.
1202    fn focusable(mut self) -> Self {
1203        self.interactivity().focusable = true;
1204        self
1205    }
1206
1207    /// Set the overflow x and y to scroll.
1208    fn overflow_scroll(mut self) -> Self {
1209        self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
1210        self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
1211        self
1212    }
1213
1214    /// Set the overflow x to scroll.
1215    fn overflow_x_scroll(mut self) -> Self {
1216        self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
1217        self
1218    }
1219
1220    /// Set the overflow y to scroll.
1221    fn overflow_y_scroll(mut self) -> Self {
1222        self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
1223        self
1224    }
1225
1226    /// Set the space to be reserved for rendering the scrollbar.
1227    ///
1228    /// This will only affect the layout of the element when overflow for this element is set to
1229    /// `Overflow::Scroll`.
1230    fn scrollbar_width(mut self, width: impl Into<AbsoluteLength>) -> Self {
1231        self.interactivity().base_style.scrollbar_width = Some(width.into());
1232        self
1233    }
1234
1235    /// Track the scroll state of this element with the given handle.
1236    fn track_scroll(mut self, scroll_handle: &ScrollHandle) -> Self {
1237        self.interactivity().tracked_scroll_handle = Some(scroll_handle.clone());
1238        self
1239    }
1240
1241    /// Track the scroll state of this element with the given handle.
1242    fn anchor_scroll(mut self, scroll_anchor: Option<ScrollAnchor>) -> Self {
1243        self.interactivity().scroll_anchor = scroll_anchor;
1244        self
1245    }
1246
1247    /// Set the given styles to be applied when this element is active.
1248    fn active(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1249    where
1250        Self: Sized,
1251    {
1252        self.interactivity().active_style = Some(Box::new(f(StyleRefinement::default())));
1253        self
1254    }
1255
1256    /// Set the given styles to be applied when this element's group is active.
1257    fn group_active(
1258        mut self,
1259        group_name: impl Into<SharedString>,
1260        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
1261    ) -> Self
1262    where
1263        Self: Sized,
1264    {
1265        self.interactivity().group_active_style = Some(GroupStyle {
1266            group: group_name.into(),
1267            style: Box::new(f(StyleRefinement::default())),
1268        });
1269        self
1270    }
1271
1272    /// Bind the given callback to click events of this element.
1273    /// The fluent API equivalent to [`Interactivity::on_click`].
1274    ///
1275    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1276    fn on_click(mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static) -> Self
1277    where
1278        Self: Sized,
1279    {
1280        self.interactivity().on_click(listener);
1281        self
1282    }
1283
1284    /// Bind the given callback to non-primary click events of this element.
1285    /// The fluent API equivalent to [`Interactivity::on_aux_click`].
1286    ///
1287    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1288    fn on_aux_click(
1289        mut self,
1290        listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static,
1291    ) -> Self
1292    where
1293        Self: Sized,
1294    {
1295        self.interactivity().on_aux_click(listener);
1296        self
1297    }
1298
1299    /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
1300    /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
1301    /// the [`InteractiveElement::on_drag_move`] API.
1302    /// The callback also has access to the offset of triggering click from the origin of parent element.
1303    /// The fluent API equivalent to [`Interactivity::on_drag`].
1304    ///
1305    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1306    fn on_drag<T, W>(
1307        mut self,
1308        value: T,
1309        constructor: impl Fn(&T, Point<Pixels>, &mut Window, &mut App) -> Entity<W> + 'static,
1310    ) -> Self
1311    where
1312        Self: Sized,
1313        T: 'static,
1314        W: 'static + Render,
1315    {
1316        self.interactivity().on_drag(value, constructor);
1317        self
1318    }
1319
1320    /// Bind the given callback on the hover start and end events of this element. Note that the boolean
1321    /// passed to the callback is true when the hover starts and false when it ends.
1322    /// The fluent API equivalent to [`Interactivity::on_hover`].
1323    ///
1324    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1325    fn on_hover(mut self, listener: impl Fn(&bool, &mut Window, &mut App) + 'static) -> Self
1326    where
1327        Self: Sized,
1328    {
1329        self.interactivity().on_hover(listener);
1330        self
1331    }
1332
1333    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
1334    /// The fluent API equivalent to [`Interactivity::tooltip`].
1335    fn tooltip(mut self, build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static) -> Self
1336    where
1337        Self: Sized,
1338    {
1339        self.interactivity().tooltip(build_tooltip);
1340        self
1341    }
1342
1343    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
1344    /// The tooltip itself is also hoverable and won't disappear when the user moves the mouse into
1345    /// the tooltip. The fluent API equivalent to [`Interactivity::hoverable_tooltip`].
1346    fn hoverable_tooltip(
1347        mut self,
1348        build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static,
1349    ) -> Self
1350    where
1351        Self: Sized,
1352    {
1353        self.interactivity().hoverable_tooltip(build_tooltip);
1354        self
1355    }
1356}
1357
1358pub(crate) type MouseDownListener =
1359    Box<dyn Fn(&MouseDownEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1360pub(crate) type MouseUpListener =
1361    Box<dyn Fn(&MouseUpEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1362pub(crate) type MousePressureListener =
1363    Box<dyn Fn(&MousePressureEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1364pub(crate) type MouseMoveListener =
1365    Box<dyn Fn(&MouseMoveEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1366
1367pub(crate) type ScrollWheelListener =
1368    Box<dyn Fn(&ScrollWheelEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1369
1370#[cfg(any(target_os = "linux", target_os = "macos"))]
1371pub(crate) type PinchListener =
1372    Box<dyn Fn(&PinchEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1373
1374pub(crate) type ClickListener = Rc<dyn Fn(&ClickEvent, &mut Window, &mut App) + 'static>;
1375
1376pub(crate) type DragListener =
1377    Box<dyn Fn(&dyn Any, Point<Pixels>, &mut Window, &mut App) -> AnyView + 'static>;
1378
1379type DropListener = Box<dyn Fn(&dyn Any, &mut Window, &mut App) + 'static>;
1380
1381type CanDropPredicate = Box<dyn Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static>;
1382
1383pub(crate) struct TooltipBuilder {
1384    build: Rc<dyn Fn(&mut Window, &mut App) -> AnyView + 'static>,
1385    hoverable: bool,
1386}
1387
1388pub(crate) type KeyDownListener =
1389    Box<dyn Fn(&KeyDownEvent, DispatchPhase, &mut Window, &mut App) + 'static>;
1390
1391pub(crate) type KeyUpListener =
1392    Box<dyn Fn(&KeyUpEvent, DispatchPhase, &mut Window, &mut App) + 'static>;
1393
1394pub(crate) type ModifiersChangedListener =
1395    Box<dyn Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static>;
1396
1397pub(crate) type ActionListener =
1398    Box<dyn Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
1399
1400/// Construct a new [`Div`] element
1401#[track_caller]
1402pub fn div() -> Div {
1403    Div {
1404        interactivity: Interactivity::new(),
1405        children: SmallVec::default(),
1406        prepaint_listener: None,
1407        image_cache: None,
1408        prepaint_order_fn: None,
1409    }
1410}
1411
1412/// A [`Div`] element, the all-in-one element for building complex UIs in GPUI
1413pub struct Div {
1414    interactivity: Interactivity,
1415    children: SmallVec<[StackSafe<AnyElement>; 2]>,
1416    prepaint_listener: Option<Box<dyn Fn(Vec<Bounds<Pixels>>, &mut Window, &mut App) + 'static>>,
1417    image_cache: Option<Box<dyn ImageCacheProvider>>,
1418    prepaint_order_fn: Option<Box<dyn Fn(&mut Window, &mut App) -> SmallVec<[usize; 8]>>>,
1419}
1420
1421impl Div {
1422    /// Add a listener to be called when the children of this `Div` are prepainted.
1423    /// This allows you to store the [`Bounds`] of the children for later use.
1424    pub fn on_children_prepainted(
1425        mut self,
1426        listener: impl Fn(Vec<Bounds<Pixels>>, &mut Window, &mut App) + 'static,
1427    ) -> Self {
1428        self.prepaint_listener = Some(Box::new(listener));
1429        self
1430    }
1431
1432    /// Add an image cache at the location of this div in the element tree.
1433    pub fn image_cache(mut self, cache: impl ImageCacheProvider) -> Self {
1434        self.image_cache = Some(Box::new(cache));
1435        self
1436    }
1437
1438    /// Specify a function that determines the order in which children are prepainted.
1439    ///
1440    /// The function is called at prepaint time and should return a vector of child indices
1441    /// in the desired prepaint order. Each index should appear exactly once.
1442    ///
1443    /// This is useful when the prepaint of one child affects state that another child reads.
1444    /// For example, in split editor views, the editor with an autoscroll request should
1445    /// be prepainted first so its scroll position update is visible to the other editor.
1446    pub fn with_dynamic_prepaint_order(
1447        mut self,
1448        order_fn: impl Fn(&mut Window, &mut App) -> SmallVec<[usize; 8]> + 'static,
1449    ) -> Self {
1450        self.prepaint_order_fn = Some(Box::new(order_fn));
1451        self
1452    }
1453}
1454
1455/// A frame state for a `Div` element, which contains layout IDs for its children.
1456///
1457/// This struct is used internally by the `Div` element to manage the layout state of its children
1458/// during the UI update cycle. It holds a small vector of `LayoutId` values, each corresponding to
1459/// a child element of the `Div`. These IDs are used to query the layout engine for the computed
1460/// bounds of the children after the layout phase is complete.
1461pub struct DivFrameState {
1462    child_layout_ids: SmallVec<[LayoutId; 2]>,
1463}
1464
1465/// Interactivity state displayed an manipulated in the inspector.
1466#[derive(Clone)]
1467pub struct DivInspectorState {
1468    /// The inspected element's base style. This is used for both inspecting and modifying the
1469    /// state. In the future it will make sense to separate the read and write, possibly tracking
1470    /// the modifications.
1471    #[cfg(any(feature = "inspector", debug_assertions))]
1472    pub base_style: Box<StyleRefinement>,
1473    /// Inspects the bounds of the element.
1474    pub bounds: Bounds<Pixels>,
1475    /// Size of the children of the element, or `bounds.size` if it has no children.
1476    pub content_size: Size<Pixels>,
1477}
1478
1479impl Styled for Div {
1480    fn style(&mut self) -> &mut StyleRefinement {
1481        &mut self.interactivity.base_style
1482    }
1483}
1484
1485impl InteractiveElement for Div {
1486    fn interactivity(&mut self) -> &mut Interactivity {
1487        &mut self.interactivity
1488    }
1489}
1490
1491impl ParentElement for Div {
1492    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
1493        self.children
1494            .extend(elements.into_iter().map(StackSafe::new))
1495    }
1496}
1497
1498impl Element for Div {
1499    type RequestLayoutState = DivFrameState;
1500    type PrepaintState = Option<Hitbox>;
1501
1502    fn id(&self) -> Option<ElementId> {
1503        self.interactivity.element_id.clone()
1504    }
1505
1506    fn source_location(&self) -> Option<&'static std::panic::Location<'static>> {
1507        self.interactivity.source_location()
1508    }
1509
1510    #[stacksafe]
1511    fn request_layout(
1512        &mut self,
1513        global_id: Option<&GlobalElementId>,
1514        inspector_id: Option<&InspectorElementId>,
1515        window: &mut Window,
1516        cx: &mut App,
1517    ) -> (LayoutId, Self::RequestLayoutState) {
1518        let mut child_layout_ids = SmallVec::new();
1519        let image_cache = self
1520            .image_cache
1521            .as_mut()
1522            .map(|provider| provider.provide(window, cx));
1523
1524        let layout_id = window.with_image_cache(image_cache, |window| {
1525            self.interactivity.request_layout(
1526                global_id,
1527                inspector_id,
1528                window,
1529                cx,
1530                |style, window, cx| {
1531                    window.with_text_style(style.text_style().cloned(), |window| {
1532                        child_layout_ids = self
1533                            .children
1534                            .iter_mut()
1535                            .map(|child| child.request_layout(window, cx))
1536                            .collect::<SmallVec<_>>();
1537                        window.request_layout(style, child_layout_ids.iter().copied(), cx)
1538                    })
1539                },
1540            )
1541        });
1542
1543        (layout_id, DivFrameState { child_layout_ids })
1544    }
1545
1546    #[stacksafe]
1547    fn prepaint(
1548        &mut self,
1549        global_id: Option<&GlobalElementId>,
1550        inspector_id: Option<&InspectorElementId>,
1551        bounds: Bounds<Pixels>,
1552        request_layout: &mut Self::RequestLayoutState,
1553        window: &mut Window,
1554        cx: &mut App,
1555    ) -> Option<Hitbox> {
1556        let image_cache = self
1557            .image_cache
1558            .as_mut()
1559            .map(|provider| provider.provide(window, cx));
1560
1561        let has_prepaint_listener = self.prepaint_listener.is_some();
1562        let mut children_bounds = Vec::with_capacity(if has_prepaint_listener {
1563            request_layout.child_layout_ids.len()
1564        } else {
1565            0
1566        });
1567
1568        let mut child_min = point(Pixels::MAX, Pixels::MAX);
1569        let mut child_max = Point::default();
1570        if let Some(handle) = self.interactivity.scroll_anchor.as_ref() {
1571            *handle.last_origin.borrow_mut() = bounds.origin - window.element_offset();
1572        }
1573        let content_size = if request_layout.child_layout_ids.is_empty() {
1574            bounds.size
1575        } else if let Some(scroll_handle) = self.interactivity.tracked_scroll_handle.as_ref() {
1576            let mut state = scroll_handle.0.borrow_mut();
1577            state.child_bounds = Vec::with_capacity(request_layout.child_layout_ids.len());
1578            for child_layout_id in &request_layout.child_layout_ids {
1579                let child_bounds = window.layout_bounds(*child_layout_id);
1580                child_min = child_min.min(&child_bounds.origin);
1581                child_max = child_max.max(&child_bounds.bottom_right());
1582                state.child_bounds.push(child_bounds);
1583            }
1584            (child_max - child_min).into()
1585        } else {
1586            for child_layout_id in &request_layout.child_layout_ids {
1587                let child_bounds = window.layout_bounds(*child_layout_id);
1588                child_min = child_min.min(&child_bounds.origin);
1589                child_max = child_max.max(&child_bounds.bottom_right());
1590
1591                if has_prepaint_listener {
1592                    children_bounds.push(child_bounds);
1593                }
1594            }
1595            (child_max - child_min).into()
1596        };
1597
1598        if let Some(scroll_handle) = self.interactivity.tracked_scroll_handle.as_ref() {
1599            scroll_handle.scroll_to_active_item();
1600        }
1601
1602        self.interactivity.prepaint(
1603            global_id,
1604            inspector_id,
1605            bounds,
1606            content_size,
1607            window,
1608            cx,
1609            |style, scroll_offset, hitbox, window, cx| {
1610                // skip children
1611                if style.display == Display::None {
1612                    return hitbox;
1613                }
1614
1615                window.with_image_cache(image_cache, |window| {
1616                    window.with_element_offset(scroll_offset, |window| {
1617                        if let Some(order_fn) = &self.prepaint_order_fn {
1618                            let order = order_fn(window, cx);
1619                            for idx in order {
1620                                if let Some(child) = self.children.get_mut(idx) {
1621                                    child.prepaint(window, cx);
1622                                }
1623                            }
1624                        } else {
1625                            for child in &mut self.children {
1626                                child.prepaint(window, cx);
1627                            }
1628                        }
1629                    });
1630
1631                    if let Some(listener) = self.prepaint_listener.as_ref() {
1632                        listener(children_bounds, window, cx);
1633                    }
1634                });
1635
1636                hitbox
1637            },
1638        )
1639    }
1640
1641    #[stacksafe]
1642    fn paint(
1643        &mut self,
1644        global_id: Option<&GlobalElementId>,
1645        inspector_id: Option<&InspectorElementId>,
1646        bounds: Bounds<Pixels>,
1647        _request_layout: &mut Self::RequestLayoutState,
1648        hitbox: &mut Option<Hitbox>,
1649        window: &mut Window,
1650        cx: &mut App,
1651    ) {
1652        let image_cache = self
1653            .image_cache
1654            .as_mut()
1655            .map(|provider| provider.provide(window, cx));
1656
1657        window.with_image_cache(image_cache, |window| {
1658            self.interactivity.paint(
1659                global_id,
1660                inspector_id,
1661                bounds,
1662                hitbox.as_ref(),
1663                window,
1664                cx,
1665                |style, window, cx| {
1666                    // skip children
1667                    if style.display == Display::None {
1668                        return;
1669                    }
1670
1671                    for child in &mut self.children {
1672                        child.paint(window, cx);
1673                    }
1674                },
1675            )
1676        });
1677    }
1678}
1679
1680impl IntoElement for Div {
1681    type Element = Self;
1682
1683    fn into_element(self) -> Self::Element {
1684        self
1685    }
1686}
1687
1688/// The interactivity struct. Powers all of the general-purpose
1689/// interactivity in the `Div` element.
1690#[derive(Default)]
1691pub struct Interactivity {
1692    /// The element ID of the element. In id is required to support a stateful subset of the interactivity such as on_click.
1693    pub element_id: Option<ElementId>,
1694    /// Whether the element was clicked. This will only be present after layout.
1695    pub active: Option<bool>,
1696    /// Whether the element was hovered. This will only be present after paint if an hitbox
1697    /// was created for the interactive element.
1698    pub hovered: Option<bool>,
1699    pub(crate) tooltip_id: Option<TooltipId>,
1700    pub(crate) content_size: Size<Pixels>,
1701    pub(crate) key_context: Option<KeyContext>,
1702    pub(crate) focusable: bool,
1703    pub(crate) tracked_focus_handle: Option<FocusHandle>,
1704    pub(crate) tracked_scroll_handle: Option<ScrollHandle>,
1705    pub(crate) scroll_anchor: Option<ScrollAnchor>,
1706    pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
1707    pub(crate) group: Option<SharedString>,
1708    /// The base style of the element, before any modifications are applied
1709    /// by focus, active, etc.
1710    pub base_style: Box<StyleRefinement>,
1711    pub(crate) focus_style: Option<Box<StyleRefinement>>,
1712    pub(crate) in_focus_style: Option<Box<StyleRefinement>>,
1713    pub(crate) focus_visible_style: Option<Box<StyleRefinement>>,
1714    pub(crate) hover_style: Option<Box<StyleRefinement>>,
1715    pub(crate) group_hover_style: Option<GroupStyle>,
1716    pub(crate) active_style: Option<Box<StyleRefinement>>,
1717    pub(crate) group_active_style: Option<GroupStyle>,
1718    pub(crate) drag_over_styles: Vec<(
1719        TypeId,
1720        Box<dyn Fn(&dyn Any, &mut Window, &mut App) -> StyleRefinement>,
1721    )>,
1722    pub(crate) group_drag_over_styles: Vec<(TypeId, GroupStyle)>,
1723    pub(crate) mouse_down_listeners: Vec<MouseDownListener>,
1724    pub(crate) mouse_up_listeners: Vec<MouseUpListener>,
1725    pub(crate) mouse_pressure_listeners: Vec<MousePressureListener>,
1726    pub(crate) mouse_move_listeners: Vec<MouseMoveListener>,
1727    pub(crate) scroll_wheel_listeners: Vec<ScrollWheelListener>,
1728    #[cfg(any(target_os = "linux", target_os = "macos"))]
1729    pub(crate) pinch_listeners: Vec<PinchListener>,
1730    pub(crate) key_down_listeners: Vec<KeyDownListener>,
1731    pub(crate) key_up_listeners: Vec<KeyUpListener>,
1732    pub(crate) modifiers_changed_listeners: Vec<ModifiersChangedListener>,
1733    pub(crate) action_listeners: Vec<(TypeId, ActionListener)>,
1734    pub(crate) drop_listeners: Vec<(TypeId, DropListener)>,
1735    pub(crate) can_drop_predicate: Option<CanDropPredicate>,
1736    pub(crate) click_listeners: Vec<ClickListener>,
1737    pub(crate) aux_click_listeners: Vec<ClickListener>,
1738    pub(crate) drag_listener: Option<(Arc<dyn Any>, DragListener)>,
1739    pub(crate) hover_listener: Option<Box<dyn Fn(&bool, &mut Window, &mut App)>>,
1740    pub(crate) tooltip_builder: Option<TooltipBuilder>,
1741    pub(crate) window_control: Option<WindowControlArea>,
1742    pub(crate) hitbox_behavior: HitboxBehavior,
1743    pub(crate) tab_index: Option<isize>,
1744    pub(crate) tab_group: bool,
1745    pub(crate) tab_stop: bool,
1746
1747    #[cfg(any(feature = "inspector", debug_assertions))]
1748    pub(crate) source_location: Option<&'static core::panic::Location<'static>>,
1749
1750    #[cfg(any(test, feature = "test-support"))]
1751    pub(crate) debug_selector: Option<String>,
1752}
1753
1754impl Interactivity {
1755    /// Layout this element according to this interactivity state's configured styles
1756    pub fn request_layout(
1757        &mut self,
1758        global_id: Option<&GlobalElementId>,
1759        _inspector_id: Option<&InspectorElementId>,
1760        window: &mut Window,
1761        cx: &mut App,
1762        f: impl FnOnce(Style, &mut Window, &mut App) -> LayoutId,
1763    ) -> LayoutId {
1764        #[cfg(any(feature = "inspector", debug_assertions))]
1765        window.with_inspector_state(
1766            _inspector_id,
1767            cx,
1768            |inspector_state: &mut Option<DivInspectorState>, _window| {
1769                if let Some(inspector_state) = inspector_state {
1770                    self.base_style = inspector_state.base_style.clone();
1771                } else {
1772                    *inspector_state = Some(DivInspectorState {
1773                        base_style: self.base_style.clone(),
1774                        bounds: Default::default(),
1775                        content_size: Default::default(),
1776                    })
1777                }
1778            },
1779        );
1780
1781        window.with_optional_element_state::<InteractiveElementState, _>(
1782            global_id,
1783            |element_state, window| {
1784                let mut element_state =
1785                    element_state.map(|element_state| element_state.unwrap_or_default());
1786
1787                if let Some(element_state) = element_state.as_ref()
1788                    && cx.has_active_drag()
1789                {
1790                    if let Some(pending_mouse_down) = element_state.pending_mouse_down.as_ref() {
1791                        *pending_mouse_down.borrow_mut() = None;
1792                    }
1793                    if let Some(clicked_state) = element_state.clicked_state.as_ref() {
1794                        *clicked_state.borrow_mut() = ElementClickedState::default();
1795                    }
1796                }
1797
1798                // Ensure we store a focus handle in our element state if we're focusable.
1799                // If there's an explicit focus handle we're tracking, use that. Otherwise
1800                // create a new handle and store it in the element state, which lives for as
1801                // as frames contain an element with this id.
1802                if self.focusable
1803                    && self.tracked_focus_handle.is_none()
1804                    && let Some(element_state) = element_state.as_mut()
1805                {
1806                    let mut handle = element_state
1807                        .focus_handle
1808                        .get_or_insert_with(|| cx.focus_handle())
1809                        .clone()
1810                        .tab_stop(self.tab_stop);
1811
1812                    if let Some(index) = self.tab_index {
1813                        handle = handle.tab_index(index);
1814                    }
1815
1816                    self.tracked_focus_handle = Some(handle);
1817                }
1818
1819                if let Some(scroll_handle) = self.tracked_scroll_handle.as_ref() {
1820                    self.scroll_offset = Some(scroll_handle.0.borrow().offset.clone());
1821                } else if (self.base_style.overflow.x == Some(Overflow::Scroll)
1822                    || self.base_style.overflow.y == Some(Overflow::Scroll))
1823                    && let Some(element_state) = element_state.as_mut()
1824                {
1825                    self.scroll_offset = Some(
1826                        element_state
1827                            .scroll_offset
1828                            .get_or_insert_with(Rc::default)
1829                            .clone(),
1830                    );
1831                }
1832
1833                let style = self.compute_style_internal(None, element_state.as_mut(), window, cx);
1834                let layout_id = f(style, window, cx);
1835                (layout_id, element_state)
1836            },
1837        )
1838    }
1839
1840    /// Commit the bounds of this element according to this interactivity state's configured styles.
1841    pub fn prepaint<R>(
1842        &mut self,
1843        global_id: Option<&GlobalElementId>,
1844        _inspector_id: Option<&InspectorElementId>,
1845        bounds: Bounds<Pixels>,
1846        content_size: Size<Pixels>,
1847        window: &mut Window,
1848        cx: &mut App,
1849        f: impl FnOnce(&Style, Point<Pixels>, Option<Hitbox>, &mut Window, &mut App) -> R,
1850    ) -> R {
1851        self.content_size = content_size;
1852
1853        #[cfg(any(feature = "inspector", debug_assertions))]
1854        window.with_inspector_state(
1855            _inspector_id,
1856            cx,
1857            |inspector_state: &mut Option<DivInspectorState>, _window| {
1858                if let Some(inspector_state) = inspector_state {
1859                    inspector_state.bounds = bounds;
1860                    inspector_state.content_size = content_size;
1861                }
1862            },
1863        );
1864
1865        if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
1866            window.set_focus_handle(focus_handle, cx);
1867        }
1868        window.with_optional_element_state::<InteractiveElementState, _>(
1869            global_id,
1870            |element_state, window| {
1871                let mut element_state =
1872                    element_state.map(|element_state| element_state.unwrap_or_default());
1873                let style = self.compute_style_internal(None, element_state.as_mut(), window, cx);
1874
1875                if let Some(element_state) = element_state.as_mut() {
1876                    if let Some(clicked_state) = element_state.clicked_state.as_ref() {
1877                        let clicked_state = clicked_state.borrow();
1878                        self.active = Some(clicked_state.element);
1879                    }
1880                    if self.hover_style.is_some() || self.group_hover_style.is_some() {
1881                        element_state
1882                            .hover_state
1883                            .get_or_insert_with(Default::default);
1884                    }
1885                    if let Some(active_tooltip) = element_state.active_tooltip.as_ref() {
1886                        if self.tooltip_builder.is_some() {
1887                            self.tooltip_id = set_tooltip_on_window(active_tooltip, window);
1888                        } else {
1889                            // If there is no longer a tooltip builder, remove the active tooltip.
1890                            element_state.active_tooltip.take();
1891                        }
1892                    }
1893                }
1894
1895                window.with_text_style(style.text_style().cloned(), |window| {
1896                    window.with_content_mask(
1897                        style.overflow_mask(bounds, window.rem_size()),
1898                        |window| {
1899                            let hitbox = if self.should_insert_hitbox(&style, window, cx) {
1900                                Some(window.insert_hitbox(bounds, self.hitbox_behavior))
1901                            } else {
1902                                None
1903                            };
1904
1905                            let scroll_offset =
1906                                self.clamp_scroll_position(bounds, &style, window, cx);
1907                            let result = f(&style, scroll_offset, hitbox, window, cx);
1908                            (result, element_state)
1909                        },
1910                    )
1911                })
1912            },
1913        )
1914    }
1915
1916    fn should_insert_hitbox(&self, style: &Style, window: &Window, cx: &App) -> bool {
1917        self.hitbox_behavior != HitboxBehavior::Normal
1918            || self.window_control.is_some()
1919            || style.mouse_cursor.is_some()
1920            || self.group.is_some()
1921            || self.scroll_offset.is_some()
1922            || self.tracked_focus_handle.is_some()
1923            || self.hover_style.is_some()
1924            || self.group_hover_style.is_some()
1925            || self.hover_listener.is_some()
1926            || !self.mouse_up_listeners.is_empty()
1927            || !self.mouse_pressure_listeners.is_empty()
1928            || !self.mouse_down_listeners.is_empty()
1929            || !self.mouse_move_listeners.is_empty()
1930            || !self.click_listeners.is_empty()
1931            || !self.aux_click_listeners.is_empty()
1932            || !self.scroll_wheel_listeners.is_empty()
1933            || self.has_pinch_listeners()
1934            || self.drag_listener.is_some()
1935            || !self.drop_listeners.is_empty()
1936            || self.tooltip_builder.is_some()
1937            || window.is_inspector_picking(cx)
1938    }
1939
1940    fn clamp_scroll_position(
1941        &self,
1942        bounds: Bounds<Pixels>,
1943        style: &Style,
1944        window: &mut Window,
1945        _cx: &mut App,
1946    ) -> Point<Pixels> {
1947        fn round_to_two_decimals(pixels: Pixels) -> Pixels {
1948            const ROUNDING_FACTOR: f32 = 100.0;
1949            (pixels * ROUNDING_FACTOR).round() / ROUNDING_FACTOR
1950        }
1951
1952        if let Some(scroll_offset) = self.scroll_offset.as_ref() {
1953            let mut scroll_to_bottom = false;
1954            let mut tracked_scroll_handle = self
1955                .tracked_scroll_handle
1956                .as_ref()
1957                .map(|handle| handle.0.borrow_mut());
1958            if let Some(mut scroll_handle_state) = tracked_scroll_handle.as_deref_mut() {
1959                scroll_handle_state.overflow = style.overflow;
1960                scroll_to_bottom = mem::take(&mut scroll_handle_state.scroll_to_bottom);
1961            }
1962
1963            let rem_size = window.rem_size();
1964            let padding = style.padding.to_pixels(bounds.size.into(), rem_size);
1965            let padding_size = size(padding.left + padding.right, padding.top + padding.bottom);
1966            // The floating point values produced by Taffy and ours often vary
1967            // slightly after ~5 decimal places. This can lead to cases where after
1968            // subtracting these, the container becomes scrollable for less than
1969            // 0.00000x pixels. As we generally don't benefit from a precision that
1970            // high for the maximum scroll, we round the scroll max to 2 decimal
1971            // places here.
1972            let padded_content_size = self.content_size + padding_size;
1973            let scroll_max = Point::from(padded_content_size - bounds.size)
1974                .map(round_to_two_decimals)
1975                .max(&Default::default());
1976            // Clamp scroll offset in case scroll max is smaller now (e.g., if children
1977            // were removed or the bounds became larger).
1978            let mut scroll_offset = scroll_offset.borrow_mut();
1979
1980            scroll_offset.x = scroll_offset.x.clamp(-scroll_max.x, px(0.));
1981            if scroll_to_bottom {
1982                scroll_offset.y = -scroll_max.y;
1983            } else {
1984                scroll_offset.y = scroll_offset.y.clamp(-scroll_max.y, px(0.));
1985            }
1986
1987            if let Some(mut scroll_handle_state) = tracked_scroll_handle {
1988                scroll_handle_state.max_offset = scroll_max;
1989                scroll_handle_state.bounds = bounds;
1990            }
1991
1992            *scroll_offset
1993        } else {
1994            Point::default()
1995        }
1996    }
1997
1998    /// Paint this element according to this interactivity state's configured styles
1999    /// and bind the element's mouse and keyboard events.
2000    ///
2001    /// content_size is the size of the content of the element, which may be larger than the
2002    /// element's bounds if the element is scrollable.
2003    ///
2004    /// the final computed style will be passed to the provided function, along
2005    /// with the current scroll offset
2006    pub fn paint(
2007        &mut self,
2008        global_id: Option<&GlobalElementId>,
2009        _inspector_id: Option<&InspectorElementId>,
2010        bounds: Bounds<Pixels>,
2011        hitbox: Option<&Hitbox>,
2012        window: &mut Window,
2013        cx: &mut App,
2014        f: impl FnOnce(&Style, &mut Window, &mut App),
2015    ) {
2016        self.hovered = hitbox.map(|hitbox| hitbox.is_hovered(window));
2017        window.with_optional_element_state::<InteractiveElementState, _>(
2018            global_id,
2019            |element_state, window| {
2020                let mut element_state =
2021                    element_state.map(|element_state| element_state.unwrap_or_default());
2022
2023                let style = self.compute_style_internal(hitbox, element_state.as_mut(), window, cx);
2024
2025                #[cfg(any(feature = "test-support", test))]
2026                if let Some(debug_selector) = &self.debug_selector {
2027                    window
2028                        .next_frame
2029                        .debug_bounds
2030                        .insert(debug_selector.clone(), bounds);
2031                }
2032
2033                self.paint_hover_group_handler(window, cx);
2034
2035                if style.visibility == Visibility::Hidden {
2036                    return ((), element_state);
2037                }
2038
2039                let mut tab_group = None;
2040                if self.tab_group {
2041                    tab_group = self.tab_index;
2042                }
2043                if let Some(focus_handle) = &self.tracked_focus_handle {
2044                    window.next_frame.tab_stops.insert(focus_handle);
2045                }
2046
2047                window.with_element_opacity(style.opacity, |window| {
2048                    style.paint(bounds, window, cx, |window: &mut Window, cx: &mut App| {
2049                        window.with_text_style(style.text_style().cloned(), |window| {
2050                            window.with_content_mask(
2051                                style.overflow_mask(bounds, window.rem_size()),
2052                                |window| {
2053                                    window.with_tab_group(tab_group, |window| {
2054                                        if let Some(hitbox) = hitbox {
2055                                            #[cfg(debug_assertions)]
2056                                            self.paint_debug_info(
2057                                                global_id, hitbox, &style, window, cx,
2058                                            );
2059
2060                                            if let Some(drag) = cx.active_drag.as_ref() {
2061                                                if let Some(mouse_cursor) = drag.cursor_style {
2062                                                    window.set_window_cursor_style(mouse_cursor);
2063                                                }
2064                                            } else {
2065                                                if let Some(mouse_cursor) = style.mouse_cursor {
2066                                                    window.set_cursor_style(mouse_cursor, hitbox);
2067                                                }
2068                                            }
2069
2070                                            if let Some(group) = self.group.clone() {
2071                                                GroupHitboxes::push(group, hitbox.id, cx);
2072                                            }
2073
2074                                            if let Some(area) = self.window_control {
2075                                                window.insert_window_control_hitbox(
2076                                                    area,
2077                                                    hitbox.clone(),
2078                                                );
2079                                            }
2080
2081                                            self.paint_mouse_listeners(
2082                                                hitbox,
2083                                                element_state.as_mut(),
2084                                                window,
2085                                                cx,
2086                                            );
2087                                            self.paint_scroll_listener(hitbox, &style, window, cx);
2088                                        }
2089
2090                                        self.paint_keyboard_listeners(window, cx);
2091                                        f(&style, window, cx);
2092
2093                                        if let Some(_hitbox) = hitbox {
2094                                            #[cfg(any(feature = "inspector", debug_assertions))]
2095                                            window.insert_inspector_hitbox(
2096                                                _hitbox.id,
2097                                                _inspector_id,
2098                                                cx,
2099                                            );
2100
2101                                            if let Some(group) = self.group.as_ref() {
2102                                                GroupHitboxes::pop(group, cx);
2103                                            }
2104                                        }
2105                                    })
2106                                },
2107                            );
2108                        });
2109                    });
2110                });
2111
2112                ((), element_state)
2113            },
2114        );
2115    }
2116
2117    #[cfg(debug_assertions)]
2118    fn paint_debug_info(
2119        &self,
2120        global_id: Option<&GlobalElementId>,
2121        hitbox: &Hitbox,
2122        style: &Style,
2123        window: &mut Window,
2124        cx: &mut App,
2125    ) {
2126        use crate::{BorderStyle, TextAlign};
2127
2128        if let Some(global_id) = global_id
2129            && (style.debug || style.debug_below || cx.has_global::<crate::DebugBelow>())
2130            && hitbox.is_hovered(window)
2131        {
2132            const FONT_SIZE: crate::Pixels = crate::Pixels(10.);
2133            let element_id = format!("{global_id:?}");
2134            let str_len = element_id.len();
2135
2136            let render_debug_text = |window: &mut Window| {
2137                if let Some(text) = window
2138                    .text_system()
2139                    .shape_text(
2140                        element_id.into(),
2141                        FONT_SIZE,
2142                        &[window.text_style().to_run(str_len)],
2143                        None,
2144                        None,
2145                    )
2146                    .ok()
2147                    .and_then(|mut text| text.pop())
2148                {
2149                    text.paint(hitbox.origin, FONT_SIZE, TextAlign::Left, None, window, cx)
2150                        .ok();
2151
2152                    let text_bounds = crate::Bounds {
2153                        origin: hitbox.origin,
2154                        size: text.size(FONT_SIZE),
2155                    };
2156                    if let Some(source_location) = self.source_location
2157                        && text_bounds.contains(&window.mouse_position())
2158                        && window.modifiers().secondary()
2159                    {
2160                        let secondary_held = window.modifiers().secondary();
2161                        window.on_key_event({
2162                            move |e: &crate::ModifiersChangedEvent, _phase, window, _cx| {
2163                                if e.modifiers.secondary() != secondary_held
2164                                    && text_bounds.contains(&window.mouse_position())
2165                                {
2166                                    window.refresh();
2167                                }
2168                            }
2169                        });
2170
2171                        let was_hovered = hitbox.is_hovered(window);
2172                        let current_view = window.current_view();
2173                        window.on_mouse_event({
2174                            let hitbox = hitbox.clone();
2175                            move |_: &MouseMoveEvent, phase, window, cx| {
2176                                if phase == DispatchPhase::Capture {
2177                                    let hovered = hitbox.is_hovered(window);
2178                                    if hovered != was_hovered {
2179                                        cx.notify(current_view)
2180                                    }
2181                                }
2182                            }
2183                        });
2184
2185                        window.on_mouse_event({
2186                            let hitbox = hitbox.clone();
2187                            move |e: &crate::MouseDownEvent, phase, window, cx| {
2188                                if text_bounds.contains(&e.position)
2189                                    && phase.capture()
2190                                    && hitbox.is_hovered(window)
2191                                {
2192                                    cx.stop_propagation();
2193                                    let Ok(dir) = std::env::current_dir() else {
2194                                        return;
2195                                    };
2196
2197                                    eprintln!(
2198                                        "This element was created at:\n{}:{}:{}",
2199                                        dir.join(source_location.file()).to_string_lossy(),
2200                                        source_location.line(),
2201                                        source_location.column()
2202                                    );
2203                                }
2204                            }
2205                        });
2206                        window.paint_quad(crate::outline(
2207                            crate::Bounds {
2208                                origin: hitbox.origin
2209                                    + crate::point(crate::px(0.), FONT_SIZE - px(2.)),
2210                                size: crate::Size {
2211                                    width: text_bounds.size.width,
2212                                    height: crate::px(1.),
2213                                },
2214                            },
2215                            crate::red(),
2216                            BorderStyle::default(),
2217                        ))
2218                    }
2219                }
2220            };
2221
2222            window.with_text_style(
2223                Some(crate::TextStyleRefinement {
2224                    color: Some(crate::red()),
2225                    line_height: Some(FONT_SIZE.into()),
2226                    background_color: Some(crate::white()),
2227                    ..Default::default()
2228                }),
2229                render_debug_text,
2230            )
2231        }
2232    }
2233
2234    fn paint_mouse_listeners(
2235        &mut self,
2236        hitbox: &Hitbox,
2237        element_state: Option<&mut InteractiveElementState>,
2238        window: &mut Window,
2239        cx: &mut App,
2240    ) {
2241        let is_focused = self
2242            .tracked_focus_handle
2243            .as_ref()
2244            .map(|handle| handle.is_focused(window))
2245            .unwrap_or(false);
2246
2247        // If this element can be focused, register a mouse down listener
2248        // that will automatically transfer focus when hitting the element.
2249        // This behavior can be suppressed by using `cx.prevent_default()`.
2250        if let Some(focus_handle) = self.tracked_focus_handle.clone() {
2251            let hitbox = hitbox.clone();
2252            window.on_mouse_event(move |_: &MouseDownEvent, phase, window, cx| {
2253                if phase == DispatchPhase::Bubble
2254                    && hitbox.is_hovered(window)
2255                    && !window.default_prevented()
2256                {
2257                    window.focus(&focus_handle, cx);
2258                    // If there is a parent that is also focusable, prevent it
2259                    // from transferring focus because we already did so.
2260                    window.prevent_default();
2261                }
2262            });
2263        }
2264
2265        for listener in self.mouse_down_listeners.drain(..) {
2266            let hitbox = hitbox.clone();
2267            window.on_mouse_event(move |event: &MouseDownEvent, phase, window, cx| {
2268                listener(event, phase, &hitbox, window, cx);
2269            })
2270        }
2271
2272        for listener in self.mouse_up_listeners.drain(..) {
2273            let hitbox = hitbox.clone();
2274            window.on_mouse_event(move |event: &MouseUpEvent, phase, window, cx| {
2275                listener(event, phase, &hitbox, window, cx);
2276            })
2277        }
2278
2279        for listener in self.mouse_pressure_listeners.drain(..) {
2280            let hitbox = hitbox.clone();
2281            window.on_mouse_event(move |event: &MousePressureEvent, phase, window, cx| {
2282                listener(event, phase, &hitbox, window, cx);
2283            })
2284        }
2285
2286        for listener in self.mouse_move_listeners.drain(..) {
2287            let hitbox = hitbox.clone();
2288            window.on_mouse_event(move |event: &MouseMoveEvent, phase, window, cx| {
2289                listener(event, phase, &hitbox, window, cx);
2290            })
2291        }
2292
2293        for listener in self.scroll_wheel_listeners.drain(..) {
2294            let hitbox = hitbox.clone();
2295            window.on_mouse_event(move |event: &ScrollWheelEvent, phase, window, cx| {
2296                listener(event, phase, &hitbox, window, cx);
2297            })
2298        }
2299
2300        #[cfg(any(target_os = "linux", target_os = "macos"))]
2301        for listener in self.pinch_listeners.drain(..) {
2302            let hitbox = hitbox.clone();
2303            window.on_mouse_event(move |event: &PinchEvent, phase, window, cx| {
2304                listener(event, phase, &hitbox, window, cx);
2305            })
2306        }
2307
2308        if self.hover_style.is_some()
2309            || self.base_style.mouse_cursor.is_some()
2310            || cx.active_drag.is_some() && !self.drag_over_styles.is_empty()
2311        {
2312            let hitbox = hitbox.clone();
2313            let hover_state = self.hover_style.as_ref().and_then(|_| {
2314                element_state
2315                    .as_ref()
2316                    .and_then(|state| state.hover_state.as_ref())
2317                    .cloned()
2318            });
2319            let current_view = window.current_view();
2320
2321            window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2322                let hovered = hitbox.is_hovered(window);
2323                let was_hovered = hover_state
2324                    .as_ref()
2325                    .is_some_and(|state| state.borrow().element);
2326                if phase == DispatchPhase::Capture && hovered != was_hovered {
2327                    if let Some(hover_state) = &hover_state {
2328                        hover_state.borrow_mut().element = hovered;
2329                        cx.notify(current_view);
2330                    }
2331                }
2332            });
2333        }
2334
2335        if let Some(group_hover) = self.group_hover_style.as_ref() {
2336            if let Some(group_hitbox_id) = GroupHitboxes::get(&group_hover.group, cx) {
2337                let hover_state = element_state
2338                    .as_ref()
2339                    .and_then(|element| element.hover_state.as_ref())
2340                    .cloned();
2341                let current_view = window.current_view();
2342
2343                window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2344                    let group_hovered = group_hitbox_id.is_hovered(window);
2345                    let was_group_hovered = hover_state
2346                        .as_ref()
2347                        .is_some_and(|state| state.borrow().group);
2348                    if phase == DispatchPhase::Capture && group_hovered != was_group_hovered {
2349                        if let Some(hover_state) = &hover_state {
2350                            hover_state.borrow_mut().group = group_hovered;
2351                        }
2352                        cx.notify(current_view);
2353                    }
2354                });
2355            }
2356        }
2357
2358        let drag_cursor_style = self.base_style.as_ref().mouse_cursor;
2359
2360        let mut drag_listener = mem::take(&mut self.drag_listener);
2361        let drop_listeners = mem::take(&mut self.drop_listeners);
2362        let click_listeners = mem::take(&mut self.click_listeners);
2363        let aux_click_listeners = mem::take(&mut self.aux_click_listeners);
2364        let can_drop_predicate = mem::take(&mut self.can_drop_predicate);
2365
2366        if !drop_listeners.is_empty() {
2367            let hitbox = hitbox.clone();
2368            window.on_mouse_event({
2369                move |_: &MouseUpEvent, phase, window, cx| {
2370                    if let Some(drag) = &cx.active_drag
2371                        && phase == DispatchPhase::Bubble
2372                        && hitbox.is_hovered(window)
2373                    {
2374                        let drag_state_type = drag.value.as_ref().type_id();
2375                        for (drop_state_type, listener) in &drop_listeners {
2376                            if *drop_state_type == drag_state_type {
2377                                let drag = cx
2378                                    .active_drag
2379                                    .take()
2380                                    .expect("checked for type drag state type above");
2381
2382                                let mut can_drop = true;
2383                                if let Some(predicate) = &can_drop_predicate {
2384                                    can_drop = predicate(drag.value.as_ref(), window, cx);
2385                                }
2386
2387                                if can_drop {
2388                                    listener(drag.value.as_ref(), window, cx);
2389                                    window.refresh();
2390                                    cx.stop_propagation();
2391                                }
2392                            }
2393                        }
2394                    }
2395                }
2396            });
2397        }
2398
2399        if let Some(element_state) = element_state {
2400            if !click_listeners.is_empty()
2401                || !aux_click_listeners.is_empty()
2402                || drag_listener.is_some()
2403            {
2404                let pending_mouse_down = element_state
2405                    .pending_mouse_down
2406                    .get_or_insert_with(Default::default)
2407                    .clone();
2408
2409                let clicked_state = element_state
2410                    .clicked_state
2411                    .get_or_insert_with(Default::default)
2412                    .clone();
2413
2414                window.on_mouse_event({
2415                    let pending_mouse_down = pending_mouse_down.clone();
2416                    let hitbox = hitbox.clone();
2417                    let has_aux_click_listeners = !aux_click_listeners.is_empty();
2418                    move |event: &MouseDownEvent, phase, window, _cx| {
2419                        if phase == DispatchPhase::Bubble
2420                            && (event.button == MouseButton::Left || has_aux_click_listeners)
2421                            && hitbox.is_hovered(window)
2422                        {
2423                            *pending_mouse_down.borrow_mut() = Some(event.clone());
2424                            window.refresh();
2425                        }
2426                    }
2427                });
2428
2429                window.on_mouse_event({
2430                    let pending_mouse_down = pending_mouse_down.clone();
2431                    let hitbox = hitbox.clone();
2432                    move |event: &MouseMoveEvent, phase, window, cx| {
2433                        if phase == DispatchPhase::Capture {
2434                            return;
2435                        }
2436
2437                        let mut pending_mouse_down = pending_mouse_down.borrow_mut();
2438                        if let Some(mouse_down) = pending_mouse_down.clone()
2439                            && !cx.has_active_drag()
2440                            && (event.position - mouse_down.position).magnitude() > DRAG_THRESHOLD
2441                            && let Some((drag_value, drag_listener)) = drag_listener.take()
2442                            && mouse_down.button == MouseButton::Left
2443                        {
2444                            *clicked_state.borrow_mut() = ElementClickedState::default();
2445                            let cursor_offset = event.position - hitbox.origin;
2446                            let drag =
2447                                (drag_listener)(drag_value.as_ref(), cursor_offset, window, cx);
2448                            cx.active_drag = Some(AnyDrag {
2449                                view: drag,
2450                                value: drag_value,
2451                                cursor_offset,
2452                                cursor_style: drag_cursor_style,
2453                            });
2454                            pending_mouse_down.take();
2455                            window.refresh();
2456                            cx.stop_propagation();
2457                        }
2458                    }
2459                });
2460
2461                if is_focused {
2462                    // Press enter, space to trigger click, when the element is focused.
2463                    window.on_key_event({
2464                        let click_listeners = click_listeners.clone();
2465                        let hitbox = hitbox.clone();
2466                        move |event: &KeyUpEvent, phase, window, cx| {
2467                            if phase.bubble() && !window.default_prevented() {
2468                                let stroke = &event.keystroke;
2469                                let keyboard_button = if stroke.key.eq("enter") {
2470                                    Some(KeyboardButton::Enter)
2471                                } else if stroke.key.eq("space") {
2472                                    Some(KeyboardButton::Space)
2473                                } else {
2474                                    None
2475                                };
2476
2477                                if let Some(button) = keyboard_button
2478                                    && !stroke.modifiers.modified()
2479                                {
2480                                    let click_event = ClickEvent::Keyboard(KeyboardClickEvent {
2481                                        button,
2482                                        bounds: hitbox.bounds,
2483                                    });
2484
2485                                    for listener in &click_listeners {
2486                                        listener(&click_event, window, cx);
2487                                    }
2488                                }
2489                            }
2490                        }
2491                    });
2492                }
2493
2494                window.on_mouse_event({
2495                    let mut captured_mouse_down = None;
2496                    let hitbox = hitbox.clone();
2497                    move |event: &MouseUpEvent, phase, window, cx| match phase {
2498                        // Clear the pending mouse down during the capture phase,
2499                        // so that it happens even if another event handler stops
2500                        // propagation.
2501                        DispatchPhase::Capture => {
2502                            let mut pending_mouse_down = pending_mouse_down.borrow_mut();
2503                            if pending_mouse_down.is_some() && hitbox.is_hovered(window) {
2504                                captured_mouse_down = pending_mouse_down.take();
2505                                window.refresh();
2506                            } else if pending_mouse_down.is_some() {
2507                                // Clear the pending mouse down event (without firing click handlers)
2508                                // if the hitbox is not being hovered.
2509                                // This avoids dragging elements that changed their position
2510                                // immediately after being clicked.
2511                                // See https://github.com/zed-industries/zed/issues/24600 for more details
2512                                pending_mouse_down.take();
2513                                window.refresh();
2514                            }
2515                        }
2516                        // Fire click handlers during the bubble phase.
2517                        DispatchPhase::Bubble => {
2518                            if let Some(mouse_down) = captured_mouse_down.take() {
2519                                let btn = mouse_down.button;
2520
2521                                let mouse_click = ClickEvent::Mouse(MouseClickEvent {
2522                                    down: mouse_down,
2523                                    up: event.clone(),
2524                                });
2525
2526                                match btn {
2527                                    MouseButton::Left => {
2528                                        for listener in &click_listeners {
2529                                            listener(&mouse_click, window, cx);
2530                                        }
2531                                    }
2532                                    _ => {
2533                                        for listener in &aux_click_listeners {
2534                                            listener(&mouse_click, window, cx);
2535                                        }
2536                                    }
2537                                }
2538                            }
2539                        }
2540                    }
2541                });
2542            }
2543
2544            if let Some(hover_listener) = self.hover_listener.take() {
2545                let hitbox = hitbox.clone();
2546                let was_hovered = element_state
2547                    .hover_listener_state
2548                    .get_or_insert_with(Default::default)
2549                    .clone();
2550                let has_mouse_down = element_state
2551                    .pending_mouse_down
2552                    .get_or_insert_with(Default::default)
2553                    .clone();
2554
2555                window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2556                    if phase != DispatchPhase::Bubble {
2557                        return;
2558                    }
2559                    let is_hovered = has_mouse_down.borrow().is_none()
2560                        && !cx.has_active_drag()
2561                        && hitbox.is_hovered(window);
2562                    let mut was_hovered = was_hovered.borrow_mut();
2563
2564                    if is_hovered != *was_hovered {
2565                        *was_hovered = is_hovered;
2566                        drop(was_hovered);
2567
2568                        hover_listener(&is_hovered, window, cx);
2569                    }
2570                });
2571            }
2572
2573            if let Some(tooltip_builder) = self.tooltip_builder.take() {
2574                let active_tooltip = element_state
2575                    .active_tooltip
2576                    .get_or_insert_with(Default::default)
2577                    .clone();
2578                let pending_mouse_down = element_state
2579                    .pending_mouse_down
2580                    .get_or_insert_with(Default::default)
2581                    .clone();
2582
2583                let tooltip_is_hoverable = tooltip_builder.hoverable;
2584                let build_tooltip = Rc::new(move |window: &mut Window, cx: &mut App| {
2585                    Some(((tooltip_builder.build)(window, cx), tooltip_is_hoverable))
2586                });
2587                // Use bounds instead of testing hitbox since this is called during prepaint.
2588                let check_is_hovered_during_prepaint = Rc::new({
2589                    let pending_mouse_down = pending_mouse_down.clone();
2590                    let source_bounds = hitbox.bounds;
2591                    move |window: &Window| {
2592                        pending_mouse_down.borrow().is_none()
2593                            && source_bounds.contains(&window.mouse_position())
2594                    }
2595                });
2596                let check_is_hovered = Rc::new({
2597                    let hitbox = hitbox.clone();
2598                    move |window: &Window| {
2599                        pending_mouse_down.borrow().is_none() && hitbox.is_hovered(window)
2600                    }
2601                });
2602                register_tooltip_mouse_handlers(
2603                    &active_tooltip,
2604                    self.tooltip_id,
2605                    build_tooltip,
2606                    check_is_hovered,
2607                    check_is_hovered_during_prepaint,
2608                    window,
2609                );
2610            }
2611
2612            // We unconditionally bind both the mouse up and mouse down active state handlers
2613            // Because we might not get a chance to render a frame before the mouse up event arrives.
2614            let active_state = element_state
2615                .clicked_state
2616                .get_or_insert_with(Default::default)
2617                .clone();
2618
2619            {
2620                let active_state = active_state.clone();
2621                window.on_mouse_event(move |_: &MouseUpEvent, phase, window, _cx| {
2622                    if phase == DispatchPhase::Capture && active_state.borrow().is_clicked() {
2623                        *active_state.borrow_mut() = ElementClickedState::default();
2624                        window.refresh();
2625                    }
2626                });
2627            }
2628
2629            {
2630                let active_group_hitbox = self
2631                    .group_active_style
2632                    .as_ref()
2633                    .and_then(|group_active| GroupHitboxes::get(&group_active.group, cx));
2634                let hitbox = hitbox.clone();
2635                window.on_mouse_event(move |_: &MouseDownEvent, phase, window, _cx| {
2636                    if phase == DispatchPhase::Bubble && !window.default_prevented() {
2637                        let group_hovered = active_group_hitbox
2638                            .is_some_and(|group_hitbox_id| group_hitbox_id.is_hovered(window));
2639                        let element_hovered = hitbox.is_hovered(window);
2640                        if group_hovered || element_hovered {
2641                            *active_state.borrow_mut() = ElementClickedState {
2642                                group: group_hovered,
2643                                element: element_hovered,
2644                            };
2645                            window.refresh();
2646                        }
2647                    }
2648                });
2649            }
2650        }
2651    }
2652
2653    fn paint_keyboard_listeners(&mut self, window: &mut Window, _cx: &mut App) {
2654        let key_down_listeners = mem::take(&mut self.key_down_listeners);
2655        let key_up_listeners = mem::take(&mut self.key_up_listeners);
2656        let modifiers_changed_listeners = mem::take(&mut self.modifiers_changed_listeners);
2657        let action_listeners = mem::take(&mut self.action_listeners);
2658        if let Some(context) = self.key_context.clone() {
2659            window.set_key_context(context);
2660        }
2661
2662        for listener in key_down_listeners {
2663            window.on_key_event(move |event: &KeyDownEvent, phase, window, cx| {
2664                listener(event, phase, window, cx);
2665            })
2666        }
2667
2668        for listener in key_up_listeners {
2669            window.on_key_event(move |event: &KeyUpEvent, phase, window, cx| {
2670                listener(event, phase, window, cx);
2671            })
2672        }
2673
2674        for listener in modifiers_changed_listeners {
2675            window.on_modifiers_changed(move |event: &ModifiersChangedEvent, window, cx| {
2676                listener(event, window, cx);
2677            })
2678        }
2679
2680        for (action_type, listener) in action_listeners {
2681            window.on_action(action_type, listener)
2682        }
2683    }
2684
2685    fn paint_hover_group_handler(&self, window: &mut Window, cx: &mut App) {
2686        let group_hitbox = self
2687            .group_hover_style
2688            .as_ref()
2689            .and_then(|group_hover| GroupHitboxes::get(&group_hover.group, cx));
2690
2691        if let Some(group_hitbox) = group_hitbox {
2692            let was_hovered = group_hitbox.is_hovered(window);
2693            let current_view = window.current_view();
2694            window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2695                let hovered = group_hitbox.is_hovered(window);
2696                if phase == DispatchPhase::Capture && hovered != was_hovered {
2697                    cx.notify(current_view);
2698                }
2699            });
2700        }
2701    }
2702
2703    fn paint_scroll_listener(
2704        &self,
2705        hitbox: &Hitbox,
2706        style: &Style,
2707        window: &mut Window,
2708        _cx: &mut App,
2709    ) {
2710        if let Some(scroll_offset) = self.scroll_offset.clone() {
2711            let overflow = style.overflow;
2712            let allow_concurrent_scroll = style.allow_concurrent_scroll;
2713            let restrict_scroll_to_axis = style.restrict_scroll_to_axis;
2714            let line_height = window.line_height();
2715            let hitbox = hitbox.clone();
2716            let current_view = window.current_view();
2717            window.on_mouse_event(move |event: &ScrollWheelEvent, phase, window, cx| {
2718                if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
2719                    let mut scroll_offset = scroll_offset.borrow_mut();
2720                    let old_scroll_offset = *scroll_offset;
2721                    let delta = event.delta.pixel_delta(line_height);
2722
2723                    let mut delta_x = Pixels::ZERO;
2724                    if overflow.x == Overflow::Scroll {
2725                        if !delta.x.is_zero() {
2726                            delta_x = delta.x;
2727                        } else if !restrict_scroll_to_axis && overflow.y != Overflow::Scroll {
2728                            delta_x = delta.y;
2729                        }
2730                    }
2731                    let mut delta_y = Pixels::ZERO;
2732                    if overflow.y == Overflow::Scroll {
2733                        if !delta.y.is_zero() {
2734                            delta_y = delta.y;
2735                        } else if !restrict_scroll_to_axis && overflow.x != Overflow::Scroll {
2736                            delta_y = delta.x;
2737                        }
2738                    }
2739                    if !allow_concurrent_scroll && !delta_x.is_zero() && !delta_y.is_zero() {
2740                        if delta_x.abs() > delta_y.abs() {
2741                            delta_y = Pixels::ZERO;
2742                        } else {
2743                            delta_x = Pixels::ZERO;
2744                        }
2745                    }
2746                    scroll_offset.y += delta_y;
2747                    scroll_offset.x += delta_x;
2748                    if *scroll_offset != old_scroll_offset {
2749                        cx.notify(current_view);
2750                    }
2751                }
2752            });
2753        }
2754    }
2755
2756    /// Compute the visual style for this element, based on the current bounds and the element's state.
2757    pub fn compute_style(
2758        &self,
2759        global_id: Option<&GlobalElementId>,
2760        hitbox: Option<&Hitbox>,
2761        window: &mut Window,
2762        cx: &mut App,
2763    ) -> Style {
2764        window.with_optional_element_state(global_id, |element_state, window| {
2765            let mut element_state =
2766                element_state.map(|element_state| element_state.unwrap_or_default());
2767            let style = self.compute_style_internal(hitbox, element_state.as_mut(), window, cx);
2768            (style, element_state)
2769        })
2770    }
2771
2772    /// Called from internal methods that have already called with_element_state.
2773    fn compute_style_internal(
2774        &self,
2775        hitbox: Option<&Hitbox>,
2776        element_state: Option<&mut InteractiveElementState>,
2777        window: &mut Window,
2778        cx: &mut App,
2779    ) -> Style {
2780        let mut style = Style::default();
2781        style.refine(&self.base_style);
2782
2783        if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
2784            if let Some(in_focus_style) = self.in_focus_style.as_ref()
2785                && focus_handle.within_focused(window, cx)
2786            {
2787                style.refine(in_focus_style);
2788            }
2789
2790            if let Some(focus_style) = self.focus_style.as_ref()
2791                && focus_handle.is_focused(window)
2792            {
2793                style.refine(focus_style);
2794            }
2795
2796            if let Some(focus_visible_style) = self.focus_visible_style.as_ref()
2797                && focus_handle.is_focused(window)
2798                && window.last_input_was_keyboard()
2799            {
2800                style.refine(focus_visible_style);
2801            }
2802        }
2803
2804        if !cx.has_active_drag() {
2805            if let Some(group_hover) = self.group_hover_style.as_ref() {
2806                let is_group_hovered =
2807                    if let Some(group_hitbox_id) = GroupHitboxes::get(&group_hover.group, cx) {
2808                        group_hitbox_id.is_hovered(window)
2809                    } else if let Some(element_state) = element_state.as_ref() {
2810                        element_state
2811                            .hover_state
2812                            .as_ref()
2813                            .map(|state| state.borrow().group)
2814                            .unwrap_or(false)
2815                    } else {
2816                        false
2817                    };
2818
2819                if is_group_hovered {
2820                    style.refine(&group_hover.style);
2821                }
2822            }
2823
2824            if let Some(hover_style) = self.hover_style.as_ref() {
2825                let is_hovered = if let Some(hitbox) = hitbox {
2826                    hitbox.is_hovered(window)
2827                } else if let Some(element_state) = element_state.as_ref() {
2828                    element_state
2829                        .hover_state
2830                        .as_ref()
2831                        .map(|state| state.borrow().element)
2832                        .unwrap_or(false)
2833                } else {
2834                    false
2835                };
2836
2837                if is_hovered {
2838                    style.refine(hover_style);
2839                }
2840            }
2841        }
2842
2843        if let Some(hitbox) = hitbox {
2844            if let Some(drag) = cx.active_drag.take() {
2845                let mut can_drop = true;
2846                if let Some(can_drop_predicate) = &self.can_drop_predicate {
2847                    can_drop = can_drop_predicate(drag.value.as_ref(), window, cx);
2848                }
2849
2850                if can_drop {
2851                    for (state_type, group_drag_style) in &self.group_drag_over_styles {
2852                        if let Some(group_hitbox_id) =
2853                            GroupHitboxes::get(&group_drag_style.group, cx)
2854                            && *state_type == drag.value.as_ref().type_id()
2855                            && group_hitbox_id.is_hovered(window)
2856                        {
2857                            style.refine(&group_drag_style.style);
2858                        }
2859                    }
2860
2861                    for (state_type, build_drag_over_style) in &self.drag_over_styles {
2862                        if *state_type == drag.value.as_ref().type_id() && hitbox.is_hovered(window)
2863                        {
2864                            style.refine(&build_drag_over_style(drag.value.as_ref(), window, cx));
2865                        }
2866                    }
2867                }
2868
2869                style.mouse_cursor = drag.cursor_style;
2870                cx.active_drag = Some(drag);
2871            }
2872        }
2873
2874        if let Some(element_state) = element_state {
2875            let clicked_state = element_state
2876                .clicked_state
2877                .get_or_insert_with(Default::default)
2878                .borrow();
2879            if clicked_state.group
2880                && let Some(group) = self.group_active_style.as_ref()
2881            {
2882                style.refine(&group.style)
2883            }
2884
2885            if let Some(active_style) = self.active_style.as_ref()
2886                && clicked_state.element
2887            {
2888                style.refine(active_style)
2889            }
2890        }
2891
2892        style
2893    }
2894}
2895
2896/// The per-frame state of an interactive element. Used for tracking stateful interactions like clicks
2897/// and scroll offsets.
2898#[derive(Default)]
2899pub struct InteractiveElementState {
2900    pub(crate) focus_handle: Option<FocusHandle>,
2901    pub(crate) clicked_state: Option<Rc<RefCell<ElementClickedState>>>,
2902    pub(crate) hover_state: Option<Rc<RefCell<ElementHoverState>>>,
2903    pub(crate) hover_listener_state: Option<Rc<RefCell<bool>>>,
2904    pub(crate) pending_mouse_down: Option<Rc<RefCell<Option<MouseDownEvent>>>>,
2905    pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
2906    pub(crate) active_tooltip: Option<Rc<RefCell<Option<ActiveTooltip>>>>,
2907}
2908
2909/// Whether or not the element or a group that contains it is clicked by the mouse.
2910#[derive(Copy, Clone, Default, Eq, PartialEq)]
2911pub struct ElementClickedState {
2912    /// True if this element's group has been clicked, false otherwise
2913    pub group: bool,
2914
2915    /// True if this element has been clicked, false otherwise
2916    pub element: bool,
2917}
2918
2919impl ElementClickedState {
2920    fn is_clicked(&self) -> bool {
2921        self.group || self.element
2922    }
2923}
2924
2925/// Whether or not the element or a group that contains it is hovered.
2926#[derive(Copy, Clone, Default, Eq, PartialEq)]
2927pub struct ElementHoverState {
2928    /// True if this element's group is hovered, false otherwise
2929    pub group: bool,
2930
2931    /// True if this element is hovered, false otherwise
2932    pub element: bool,
2933}
2934
2935pub(crate) enum ActiveTooltip {
2936    /// Currently delaying before showing the tooltip.
2937    WaitingForShow { _task: Task<()> },
2938    /// Tooltip is visible, element was hovered or for hoverable tooltips, the tooltip was hovered.
2939    Visible {
2940        tooltip: AnyTooltip,
2941        is_hoverable: bool,
2942    },
2943    /// Tooltip is visible and hoverable, but the mouse is no longer hovering. Currently delaying
2944    /// before hiding it.
2945    WaitingForHide {
2946        tooltip: AnyTooltip,
2947        _task: Task<()>,
2948    },
2949}
2950
2951pub(crate) fn clear_active_tooltip(
2952    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2953    window: &mut Window,
2954) {
2955    match active_tooltip.borrow_mut().take() {
2956        None => {}
2957        Some(ActiveTooltip::WaitingForShow { .. }) => {}
2958        Some(ActiveTooltip::Visible { .. }) => window.refresh(),
2959        Some(ActiveTooltip::WaitingForHide { .. }) => window.refresh(),
2960    }
2961}
2962
2963pub(crate) fn clear_active_tooltip_if_not_hoverable(
2964    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2965    window: &mut Window,
2966) {
2967    let should_clear = match active_tooltip.borrow().as_ref() {
2968        None => false,
2969        Some(ActiveTooltip::WaitingForShow { .. }) => false,
2970        Some(ActiveTooltip::Visible { is_hoverable, .. }) => !is_hoverable,
2971        Some(ActiveTooltip::WaitingForHide { .. }) => false,
2972    };
2973    if should_clear {
2974        active_tooltip.borrow_mut().take();
2975        window.refresh();
2976    }
2977}
2978
2979pub(crate) fn set_tooltip_on_window(
2980    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2981    window: &mut Window,
2982) -> Option<TooltipId> {
2983    let tooltip = match active_tooltip.borrow().as_ref() {
2984        None => return None,
2985        Some(ActiveTooltip::WaitingForShow { .. }) => return None,
2986        Some(ActiveTooltip::Visible { tooltip, .. }) => tooltip.clone(),
2987        Some(ActiveTooltip::WaitingForHide { tooltip, .. }) => tooltip.clone(),
2988    };
2989    Some(window.set_tooltip(tooltip))
2990}
2991
2992pub(crate) fn register_tooltip_mouse_handlers(
2993    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2994    tooltip_id: Option<TooltipId>,
2995    build_tooltip: Rc<dyn Fn(&mut Window, &mut App) -> Option<(AnyView, bool)>>,
2996    check_is_hovered: Rc<dyn Fn(&Window) -> bool>,
2997    check_is_hovered_during_prepaint: Rc<dyn Fn(&Window) -> bool>,
2998    window: &mut Window,
2999) {
3000    window.on_mouse_event({
3001        let active_tooltip = active_tooltip.clone();
3002        let build_tooltip = build_tooltip.clone();
3003        let check_is_hovered = check_is_hovered.clone();
3004        move |_: &MouseMoveEvent, phase, window, cx| {
3005            handle_tooltip_mouse_move(
3006                &active_tooltip,
3007                &build_tooltip,
3008                &check_is_hovered,
3009                &check_is_hovered_during_prepaint,
3010                phase,
3011                window,
3012                cx,
3013            )
3014        }
3015    });
3016
3017    window.on_mouse_event({
3018        let active_tooltip = active_tooltip.clone();
3019        move |_: &MouseDownEvent, _phase, window: &mut Window, _cx| {
3020            if !tooltip_id.is_some_and(|tooltip_id| tooltip_id.is_hovered(window)) {
3021                clear_active_tooltip_if_not_hoverable(&active_tooltip, window);
3022            }
3023        }
3024    });
3025
3026    window.on_mouse_event({
3027        let active_tooltip = active_tooltip.clone();
3028        move |_: &ScrollWheelEvent, _phase, window: &mut Window, _cx| {
3029            if !tooltip_id.is_some_and(|tooltip_id| tooltip_id.is_hovered(window)) {
3030                clear_active_tooltip_if_not_hoverable(&active_tooltip, window);
3031            }
3032        }
3033    });
3034}
3035
3036/// Handles displaying tooltips when an element is hovered.
3037///
3038/// The mouse hovering logic also relies on being called from window prepaint in order to handle the
3039/// case where the element the tooltip is on is not rendered - in that case its mouse listeners are
3040/// also not registered. During window prepaint, the hitbox information is not available, so
3041/// `check_is_hovered_during_prepaint` is used which bases the check off of the absolute bounds of
3042/// the element.
3043///
3044/// TODO: There's a minor bug due to the use of absolute bounds while checking during prepaint - it
3045/// does not know if the hitbox is occluded. In the case where a tooltip gets displayed and then
3046/// gets occluded after display, it will stick around until the mouse exits the hover bounds.
3047fn handle_tooltip_mouse_move(
3048    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3049    build_tooltip: &Rc<dyn Fn(&mut Window, &mut App) -> Option<(AnyView, bool)>>,
3050    check_is_hovered: &Rc<dyn Fn(&Window) -> bool>,
3051    check_is_hovered_during_prepaint: &Rc<dyn Fn(&Window) -> bool>,
3052    phase: DispatchPhase,
3053    window: &mut Window,
3054    cx: &mut App,
3055) {
3056    // Separates logic for what mutation should occur from applying it, to avoid overlapping
3057    // RefCell borrows.
3058    enum Action {
3059        None,
3060        CancelShow,
3061        ScheduleShow,
3062    }
3063
3064    let action = match active_tooltip.borrow().as_ref() {
3065        None => {
3066            let is_hovered = check_is_hovered(window);
3067            if is_hovered && phase.bubble() {
3068                Action::ScheduleShow
3069            } else {
3070                Action::None
3071            }
3072        }
3073        Some(ActiveTooltip::WaitingForShow { .. }) => {
3074            let is_hovered = check_is_hovered(window);
3075            if is_hovered {
3076                Action::None
3077            } else {
3078                Action::CancelShow
3079            }
3080        }
3081        // These are handled in check_visible_and_update.
3082        Some(ActiveTooltip::Visible { .. }) | Some(ActiveTooltip::WaitingForHide { .. }) => {
3083            Action::None
3084        }
3085    };
3086
3087    match action {
3088        Action::None => {}
3089        Action::CancelShow => {
3090            // Cancel waiting to show tooltip when it is no longer hovered.
3091            active_tooltip.borrow_mut().take();
3092        }
3093        Action::ScheduleShow => {
3094            let delayed_show_task = window.spawn(cx, {
3095                let active_tooltip = active_tooltip.clone();
3096                let build_tooltip = build_tooltip.clone();
3097                let check_is_hovered_during_prepaint = check_is_hovered_during_prepaint.clone();
3098                async move |cx| {
3099                    cx.background_executor().timer(TOOLTIP_SHOW_DELAY).await;
3100                    cx.update(|window, cx| {
3101                        let new_tooltip =
3102                            build_tooltip(window, cx).map(|(view, tooltip_is_hoverable)| {
3103                                let active_tooltip = active_tooltip.clone();
3104                                ActiveTooltip::Visible {
3105                                    tooltip: AnyTooltip {
3106                                        view,
3107                                        mouse_position: window.mouse_position(),
3108                                        check_visible_and_update: Rc::new(
3109                                            move |tooltip_bounds, window, cx| {
3110                                                handle_tooltip_check_visible_and_update(
3111                                                    &active_tooltip,
3112                                                    tooltip_is_hoverable,
3113                                                    &check_is_hovered_during_prepaint,
3114                                                    tooltip_bounds,
3115                                                    window,
3116                                                    cx,
3117                                                )
3118                                            },
3119                                        ),
3120                                    },
3121                                    is_hoverable: tooltip_is_hoverable,
3122                                }
3123                            });
3124                        *active_tooltip.borrow_mut() = new_tooltip;
3125                        window.refresh();
3126                    })
3127                    .ok();
3128                }
3129            });
3130            active_tooltip
3131                .borrow_mut()
3132                .replace(ActiveTooltip::WaitingForShow {
3133                    _task: delayed_show_task,
3134                });
3135        }
3136    }
3137}
3138
3139/// Returns a callback which will be called by window prepaint to update tooltip visibility. The
3140/// purpose of doing this logic here instead of the mouse move handler is that the mouse move
3141/// handler won't get called when the element is not painted (e.g. via use of `visible_on_hover`).
3142fn handle_tooltip_check_visible_and_update(
3143    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3144    tooltip_is_hoverable: bool,
3145    check_is_hovered: &Rc<dyn Fn(&Window) -> bool>,
3146    tooltip_bounds: Bounds<Pixels>,
3147    window: &mut Window,
3148    cx: &mut App,
3149) -> bool {
3150    // Separates logic for what mutation should occur from applying it, to avoid overlapping RefCell
3151    // borrows.
3152    enum Action {
3153        None,
3154        Hide,
3155        ScheduleHide(AnyTooltip),
3156        CancelHide(AnyTooltip),
3157    }
3158
3159    let is_hovered = check_is_hovered(window)
3160        || (tooltip_is_hoverable && tooltip_bounds.contains(&window.mouse_position()));
3161    let action = match active_tooltip.borrow().as_ref() {
3162        Some(ActiveTooltip::Visible { tooltip, .. }) => {
3163            if is_hovered {
3164                Action::None
3165            } else {
3166                if tooltip_is_hoverable {
3167                    Action::ScheduleHide(tooltip.clone())
3168                } else {
3169                    Action::Hide
3170                }
3171            }
3172        }
3173        Some(ActiveTooltip::WaitingForHide { tooltip, .. }) => {
3174            if is_hovered {
3175                Action::CancelHide(tooltip.clone())
3176            } else {
3177                Action::None
3178            }
3179        }
3180        None | Some(ActiveTooltip::WaitingForShow { .. }) => Action::None,
3181    };
3182
3183    match action {
3184        Action::None => {}
3185        Action::Hide => clear_active_tooltip(active_tooltip, window),
3186        Action::ScheduleHide(tooltip) => {
3187            let delayed_hide_task = window.spawn(cx, {
3188                let active_tooltip = active_tooltip.clone();
3189                async move |cx| {
3190                    cx.background_executor()
3191                        .timer(HOVERABLE_TOOLTIP_HIDE_DELAY)
3192                        .await;
3193                    if active_tooltip.borrow_mut().take().is_some() {
3194                        cx.update(|window, _cx| window.refresh()).ok();
3195                    }
3196                }
3197            });
3198            active_tooltip
3199                .borrow_mut()
3200                .replace(ActiveTooltip::WaitingForHide {
3201                    tooltip,
3202                    _task: delayed_hide_task,
3203                });
3204        }
3205        Action::CancelHide(tooltip) => {
3206            // Cancel waiting to hide tooltip when it becomes hovered.
3207            active_tooltip.borrow_mut().replace(ActiveTooltip::Visible {
3208                tooltip,
3209                is_hoverable: true,
3210            });
3211        }
3212    }
3213
3214    active_tooltip.borrow().is_some()
3215}
3216
3217#[derive(Default)]
3218pub(crate) struct GroupHitboxes(HashMap<SharedString, SmallVec<[HitboxId; 1]>>);
3219
3220impl Global for GroupHitboxes {}
3221
3222impl GroupHitboxes {
3223    pub fn get(name: &SharedString, cx: &mut App) -> Option<HitboxId> {
3224        cx.default_global::<Self>()
3225            .0
3226            .get(name)
3227            .and_then(|bounds_stack| bounds_stack.last())
3228            .cloned()
3229    }
3230
3231    pub fn push(name: SharedString, hitbox_id: HitboxId, cx: &mut App) {
3232        cx.default_global::<Self>()
3233            .0
3234            .entry(name)
3235            .or_default()
3236            .push(hitbox_id);
3237    }
3238
3239    pub fn pop(name: &SharedString, cx: &mut App) {
3240        cx.default_global::<Self>().0.get_mut(name).unwrap().pop();
3241    }
3242}
3243
3244/// A wrapper around an element that can store state, produced after assigning an ElementId.
3245pub struct Stateful<E> {
3246    pub(crate) element: E,
3247}
3248
3249impl<E> Styled for Stateful<E>
3250where
3251    E: Styled,
3252{
3253    fn style(&mut self) -> &mut StyleRefinement {
3254        self.element.style()
3255    }
3256}
3257
3258impl<E> StatefulInteractiveElement for Stateful<E>
3259where
3260    E: Element,
3261    Self: InteractiveElement,
3262{
3263}
3264
3265impl<E> InteractiveElement for Stateful<E>
3266where
3267    E: InteractiveElement,
3268{
3269    fn interactivity(&mut self) -> &mut Interactivity {
3270        self.element.interactivity()
3271    }
3272}
3273
3274impl<E> Element for Stateful<E>
3275where
3276    E: Element,
3277{
3278    type RequestLayoutState = E::RequestLayoutState;
3279    type PrepaintState = E::PrepaintState;
3280
3281    fn id(&self) -> Option<ElementId> {
3282        self.element.id()
3283    }
3284
3285    fn source_location(&self) -> Option<&'static core::panic::Location<'static>> {
3286        self.element.source_location()
3287    }
3288
3289    fn request_layout(
3290        &mut self,
3291        id: Option<&GlobalElementId>,
3292        inspector_id: Option<&InspectorElementId>,
3293        window: &mut Window,
3294        cx: &mut App,
3295    ) -> (LayoutId, Self::RequestLayoutState) {
3296        self.element.request_layout(id, inspector_id, window, cx)
3297    }
3298
3299    fn prepaint(
3300        &mut self,
3301        id: Option<&GlobalElementId>,
3302        inspector_id: Option<&InspectorElementId>,
3303        bounds: Bounds<Pixels>,
3304        state: &mut Self::RequestLayoutState,
3305        window: &mut Window,
3306        cx: &mut App,
3307    ) -> E::PrepaintState {
3308        self.element
3309            .prepaint(id, inspector_id, bounds, state, window, cx)
3310    }
3311
3312    fn paint(
3313        &mut self,
3314        id: Option<&GlobalElementId>,
3315        inspector_id: Option<&InspectorElementId>,
3316        bounds: Bounds<Pixels>,
3317        request_layout: &mut Self::RequestLayoutState,
3318        prepaint: &mut Self::PrepaintState,
3319        window: &mut Window,
3320        cx: &mut App,
3321    ) {
3322        self.element.paint(
3323            id,
3324            inspector_id,
3325            bounds,
3326            request_layout,
3327            prepaint,
3328            window,
3329            cx,
3330        );
3331    }
3332}
3333
3334impl<E> IntoElement for Stateful<E>
3335where
3336    E: Element,
3337{
3338    type Element = Self;
3339
3340    fn into_element(self) -> Self::Element {
3341        self
3342    }
3343}
3344
3345impl<E> ParentElement for Stateful<E>
3346where
3347    E: ParentElement,
3348{
3349    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
3350        self.element.extend(elements)
3351    }
3352}
3353
3354/// Represents an element that can be scrolled *to* in its parent element.
3355/// Contrary to [ScrollHandle::scroll_to_active_item], an anchored element does not have to be an immediate child of the parent.
3356#[derive(Clone)]
3357pub struct ScrollAnchor {
3358    handle: ScrollHandle,
3359    last_origin: Rc<RefCell<Point<Pixels>>>,
3360}
3361
3362impl ScrollAnchor {
3363    /// Creates a [ScrollAnchor] associated with a given [ScrollHandle].
3364    pub fn for_handle(handle: ScrollHandle) -> Self {
3365        Self {
3366            handle,
3367            last_origin: Default::default(),
3368        }
3369    }
3370    /// Request scroll to this item on the next frame.
3371    pub fn scroll_to(&self, window: &mut Window, _cx: &mut App) {
3372        let this = self.clone();
3373
3374        window.on_next_frame(move |_, _| {
3375            let viewport_bounds = this.handle.bounds();
3376            let self_bounds = *this.last_origin.borrow();
3377            this.handle.set_offset(viewport_bounds.origin - self_bounds);
3378        });
3379    }
3380}
3381
3382#[derive(Default, Debug)]
3383struct ScrollHandleState {
3384    offset: Rc<RefCell<Point<Pixels>>>,
3385    bounds: Bounds<Pixels>,
3386    max_offset: Point<Pixels>,
3387    child_bounds: Vec<Bounds<Pixels>>,
3388    scroll_to_bottom: bool,
3389    overflow: Point<Overflow>,
3390    active_item: Option<ScrollActiveItem>,
3391}
3392
3393#[derive(Default, Debug, Clone, Copy)]
3394struct ScrollActiveItem {
3395    index: usize,
3396    strategy: ScrollStrategy,
3397}
3398
3399#[derive(Default, Debug, Clone, Copy)]
3400enum ScrollStrategy {
3401    #[default]
3402    FirstVisible,
3403    Top,
3404}
3405
3406/// A handle to the scrollable aspects of an element.
3407/// Used for accessing scroll state, like the current scroll offset,
3408/// and for mutating the scroll state, like scrolling to a specific child.
3409#[derive(Clone, Debug)]
3410pub struct ScrollHandle(Rc<RefCell<ScrollHandleState>>);
3411
3412impl Default for ScrollHandle {
3413    fn default() -> Self {
3414        Self::new()
3415    }
3416}
3417
3418impl ScrollHandle {
3419    /// Construct a new scroll handle.
3420    pub fn new() -> Self {
3421        Self(Rc::default())
3422    }
3423
3424    /// Get the current scroll offset.
3425    pub fn offset(&self) -> Point<Pixels> {
3426        *self.0.borrow().offset.borrow()
3427    }
3428
3429    /// Get the maximum scroll offset.
3430    pub fn max_offset(&self) -> Point<Pixels> {
3431        self.0.borrow().max_offset
3432    }
3433
3434    /// Get the top child that's scrolled into view.
3435    pub fn top_item(&self) -> usize {
3436        let state = self.0.borrow();
3437        let top = state.bounds.top() - state.offset.borrow().y;
3438
3439        match state.child_bounds.binary_search_by(|bounds| {
3440            if top < bounds.top() {
3441                Ordering::Greater
3442            } else if top > bounds.bottom() {
3443                Ordering::Less
3444            } else {
3445                Ordering::Equal
3446            }
3447        }) {
3448            Ok(ix) => ix,
3449            Err(ix) => ix.min(state.child_bounds.len().saturating_sub(1)),
3450        }
3451    }
3452
3453    /// Get the bottom child that's scrolled into view.
3454    pub fn bottom_item(&self) -> usize {
3455        let state = self.0.borrow();
3456        let bottom = state.bounds.bottom() - state.offset.borrow().y;
3457
3458        match state.child_bounds.binary_search_by(|bounds| {
3459            if bottom < bounds.top() {
3460                Ordering::Greater
3461            } else if bottom > bounds.bottom() {
3462                Ordering::Less
3463            } else {
3464                Ordering::Equal
3465            }
3466        }) {
3467            Ok(ix) => ix,
3468            Err(ix) => ix.min(state.child_bounds.len().saturating_sub(1)),
3469        }
3470    }
3471
3472    /// Return the bounds into which this child is painted
3473    pub fn bounds(&self) -> Bounds<Pixels> {
3474        self.0.borrow().bounds
3475    }
3476
3477    /// Get the bounds for a specific child.
3478    pub fn bounds_for_item(&self, ix: usize) -> Option<Bounds<Pixels>> {
3479        self.0.borrow().child_bounds.get(ix).cloned()
3480    }
3481
3482    /// Update [ScrollHandleState]'s active item for scrolling to in prepaint
3483    pub fn scroll_to_item(&self, ix: usize) {
3484        let mut state = self.0.borrow_mut();
3485        state.active_item = Some(ScrollActiveItem {
3486            index: ix,
3487            strategy: ScrollStrategy::default(),
3488        });
3489    }
3490
3491    /// Update [ScrollHandleState]'s active item for scrolling to in prepaint
3492    /// This scrolls the minimal amount to ensure that the child is the first visible element
3493    pub fn scroll_to_top_of_item(&self, ix: usize) {
3494        let mut state = self.0.borrow_mut();
3495        state.active_item = Some(ScrollActiveItem {
3496            index: ix,
3497            strategy: ScrollStrategy::Top,
3498        });
3499    }
3500
3501    /// Scrolls the minimal amount to either ensure that the child is
3502    /// fully visible or the top element of the view depends on the
3503    /// scroll strategy
3504    fn scroll_to_active_item(&self) {
3505        let mut state = self.0.borrow_mut();
3506
3507        let Some(active_item) = state.active_item else {
3508            return;
3509        };
3510
3511        let active_item = match state.child_bounds.get(active_item.index) {
3512            Some(bounds) => {
3513                let mut scroll_offset = state.offset.borrow_mut();
3514
3515                match active_item.strategy {
3516                    ScrollStrategy::FirstVisible => {
3517                        if state.overflow.y == Overflow::Scroll {
3518                            let child_height = bounds.size.height;
3519                            let viewport_height = state.bounds.size.height;
3520                            if child_height > viewport_height {
3521                                scroll_offset.y = state.bounds.top() - bounds.top();
3522                            } else if bounds.top() + scroll_offset.y < state.bounds.top() {
3523                                scroll_offset.y = state.bounds.top() - bounds.top();
3524                            } else if bounds.bottom() + scroll_offset.y > state.bounds.bottom() {
3525                                scroll_offset.y = state.bounds.bottom() - bounds.bottom();
3526                            }
3527                        }
3528                    }
3529                    ScrollStrategy::Top => {
3530                        scroll_offset.y = state.bounds.top() - bounds.top();
3531                    }
3532                }
3533
3534                if state.overflow.x == Overflow::Scroll {
3535                    let child_width = bounds.size.width;
3536                    let viewport_width = state.bounds.size.width;
3537                    if child_width > viewport_width {
3538                        scroll_offset.x = state.bounds.left() - bounds.left();
3539                    } else if bounds.left() + scroll_offset.x < state.bounds.left() {
3540                        scroll_offset.x = state.bounds.left() - bounds.left();
3541                    } else if bounds.right() + scroll_offset.x > state.bounds.right() {
3542                        scroll_offset.x = state.bounds.right() - bounds.right();
3543                    }
3544                }
3545                None
3546            }
3547            None => Some(active_item),
3548        };
3549        state.active_item = active_item;
3550    }
3551
3552    /// Scrolls to the bottom.
3553    pub fn scroll_to_bottom(&self) {
3554        let mut state = self.0.borrow_mut();
3555        state.scroll_to_bottom = true;
3556    }
3557
3558    /// Set the offset explicitly. The offset is the distance from the top left of the
3559    /// parent container to the top left of the first child.
3560    /// As you scroll further down the offset becomes more negative.
3561    pub fn set_offset(&self, mut position: Point<Pixels>) {
3562        let state = self.0.borrow();
3563        *state.offset.borrow_mut() = position;
3564    }
3565
3566    /// Get the logical scroll top, based on a child index and a pixel offset.
3567    pub fn logical_scroll_top(&self) -> (usize, Pixels) {
3568        let ix = self.top_item();
3569        let state = self.0.borrow();
3570
3571        if let Some(child_bounds) = state.child_bounds.get(ix) {
3572            (
3573                ix,
3574                child_bounds.top() + state.offset.borrow().y - state.bounds.top(),
3575            )
3576        } else {
3577            (ix, px(0.))
3578        }
3579    }
3580
3581    /// Get the logical scroll bottom, based on a child index and a pixel offset.
3582    pub fn logical_scroll_bottom(&self) -> (usize, Pixels) {
3583        let ix = self.bottom_item();
3584        let state = self.0.borrow();
3585
3586        if let Some(child_bounds) = state.child_bounds.get(ix) {
3587            (
3588                ix,
3589                child_bounds.bottom() + state.offset.borrow().y - state.bounds.bottom(),
3590            )
3591        } else {
3592            (ix, px(0.))
3593        }
3594    }
3595
3596    /// Get the count of children for scrollable item.
3597    pub fn children_count(&self) -> usize {
3598        self.0.borrow().child_bounds.len()
3599    }
3600}
3601
3602#[cfg(test)]
3603mod tests {
3604    use super::*;
3605
3606    #[test]
3607    fn scroll_handle_aligns_wide_children_to_left_edge() {
3608        let handle = ScrollHandle::new();
3609        {
3610            let mut state = handle.0.borrow_mut();
3611            state.bounds = Bounds::new(point(px(0.), px(0.)), size(px(80.), px(20.)));
3612            state.child_bounds = vec![Bounds::new(point(px(25.), px(0.)), size(px(200.), px(20.)))];
3613            state.overflow.x = Overflow::Scroll;
3614            state.active_item = Some(ScrollActiveItem {
3615                index: 0,
3616                strategy: ScrollStrategy::default(),
3617            });
3618        }
3619
3620        handle.scroll_to_active_item();
3621
3622        assert_eq!(handle.offset().x, px(-25.));
3623    }
3624
3625    #[test]
3626    fn scroll_handle_aligns_tall_children_to_top_edge() {
3627        let handle = ScrollHandle::new();
3628        {
3629            let mut state = handle.0.borrow_mut();
3630            state.bounds = Bounds::new(point(px(0.), px(0.)), size(px(20.), px(80.)));
3631            state.child_bounds = vec![Bounds::new(point(px(0.), px(25.)), size(px(20.), px(200.)))];
3632            state.overflow.y = Overflow::Scroll;
3633            state.active_item = Some(ScrollActiveItem {
3634                index: 0,
3635                strategy: ScrollStrategy::default(),
3636            });
3637        }
3638
3639        handle.scroll_to_active_item();
3640
3641        assert_eq!(handle.offset().y, px(-25.));
3642    }
3643}