div.rs

   1//! Div is the central, reusable element that most GPUI trees will be built from.
   2//! It functions as a container for other elements, and provides a number of
   3//! useful features for laying out and styling its children as well as binding
   4//! mouse events and action handlers. It is meant to be similar to the HTML `<div>`
   5//! element, but for GPUI.
   6//!
   7//! # Build your own div
   8//!
   9//! GPUI does not directly provide APIs for stateful, multi step events like `click`
  10//! and `drag`. We want GPUI users to be able to build their own abstractions for
  11//! their own needs. However, as a UI framework, we're also obliged to provide some
  12//! building blocks to make the process of building your own elements easier.
  13//! For this we have the [`Interactivity`] and the [`StyleRefinement`] structs, as well
  14//! as several associated traits. Together, these provide the full suite of Dom-like events
  15//! and Tailwind-like styling that you can use to build your own custom elements. Div is
  16//! constructed by combining these two systems into an all-in-one element.
  17
  18use crate::{
  19    Action, AnyDrag, AnyElement, AnyTooltip, AnyView, App, Bounds, ClickEvent, DispatchPhase,
  20    Element, ElementId, Entity, FocusHandle, Global, GlobalElementId, Hitbox, HitboxBehavior,
  21    HitboxId, InspectorElementId, IntoElement, IsZero, KeyContext, KeyDownEvent, KeyUpEvent,
  22    KeyboardButton, KeyboardClickEvent, LayoutId, ModifiersChangedEvent, MouseButton,
  23    MouseClickEvent, MouseDownEvent, MouseMoveEvent, MouseUpEvent, Overflow, ParentElement, Pixels,
  24    Point, Render, ScrollWheelEvent, SharedString, Size, Style, StyleRefinement, Styled, Task,
  25    TooltipId, Visibility, Window, WindowControlArea, point, px, size,
  26    taffy::{CONTAINER_LAYOUT_ID_TO_DEBUG, LAYOUT_ID_TO_DEBUG, LOG_TAFFY},
  27};
  28use collections::HashMap;
  29use refineable::Refineable;
  30use smallvec::SmallVec;
  31use std::{
  32    any::{Any, TypeId},
  33    cell::RefCell,
  34    cmp::Ordering,
  35    fmt::Debug,
  36    marker::PhantomData,
  37    mem,
  38    rc::Rc,
  39    sync::Arc,
  40    time::Duration,
  41};
  42use util::ResultExt;
  43
  44use super::ImageCacheProvider;
  45
  46const DRAG_THRESHOLD: f64 = 2.;
  47const TOOLTIP_SHOW_DELAY: Duration = Duration::from_millis(500);
  48const HOVERABLE_TOOLTIP_HIDE_DELAY: Duration = Duration::from_millis(500);
  49
  50/// The styling information for a given group.
  51pub struct GroupStyle {
  52    /// The identifier for this group.
  53    pub group: SharedString,
  54
  55    /// The specific style refinement that this group would apply
  56    /// to its children.
  57    pub style: Box<StyleRefinement>,
  58}
  59
  60/// An event for when a drag is moving over this element, with the given state type.
  61pub struct DragMoveEvent<T> {
  62    /// The mouse move event that triggered this drag move event.
  63    pub event: MouseMoveEvent,
  64
  65    /// The bounds of this element.
  66    pub bounds: Bounds<Pixels>,
  67    drag: PhantomData<T>,
  68    dragged_item: Arc<dyn Any>,
  69}
  70
  71impl<T: 'static> DragMoveEvent<T> {
  72    /// Returns the drag state for this event.
  73    pub fn drag<'b>(&self, cx: &'b App) -> &'b T {
  74        cx.active_drag
  75            .as_ref()
  76            .and_then(|drag| drag.value.downcast_ref::<T>())
  77            .expect("DragMoveEvent is only valid when the stored active drag is of the same type.")
  78    }
  79
  80    /// An item that is about to be dropped.
  81    pub fn dragged_item(&self) -> &dyn Any {
  82        self.dragged_item.as_ref()
  83    }
  84}
  85
  86impl Interactivity {
  87    /// Create an `Interactivity`, capturing the caller location in debug mode.
  88    #[cfg(any(feature = "inspector", debug_assertions))]
  89    #[track_caller]
  90    pub fn new() -> Interactivity {
  91        Interactivity {
  92            source_location: Some(core::panic::Location::caller()),
  93            ..Default::default()
  94        }
  95    }
  96
  97    /// Create an `Interactivity`, capturing the caller location in debug mode.
  98    #[cfg(not(any(feature = "inspector", debug_assertions)))]
  99    pub fn new() -> Interactivity {
 100        Interactivity::default()
 101    }
 102
 103    /// Gets the source location of construction. Returns `None` when not in debug mode.
 104    pub fn source_location(&self) -> Option<&'static std::panic::Location<'static>> {
 105        #[cfg(any(feature = "inspector", debug_assertions))]
 106        {
 107            self.source_location
 108        }
 109
 110        #[cfg(not(any(feature = "inspector", debug_assertions)))]
 111        {
 112            None
 113        }
 114    }
 115
 116    /// Bind the given callback to the mouse down event for the given mouse button, during the bubble phase
 117    /// The imperative API equivalent of [`InteractiveElement::on_mouse_down`]
 118    ///
 119    /// See [`Context::listener`](crate::Context::listener) to get access to the view state from this callback.
 120    pub fn on_mouse_down(
 121        &mut self,
 122        button: MouseButton,
 123        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 124    ) {
 125        self.mouse_down_listeners
 126            .push(Box::new(move |event, phase, hitbox, window, cx| {
 127                if phase == DispatchPhase::Bubble
 128                    && event.button == button
 129                    && hitbox.is_hovered(window)
 130                {
 131                    (listener)(event, window, cx)
 132                }
 133            }));
 134    }
 135
 136    /// Bind the given callback to the mouse down event for any button, during the capture phase
 137    /// The imperative API equivalent of [`InteractiveElement::capture_any_mouse_down`]
 138    ///
 139    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 140    pub fn capture_any_mouse_down(
 141        &mut self,
 142        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 143    ) {
 144        self.mouse_down_listeners
 145            .push(Box::new(move |event, phase, hitbox, window, cx| {
 146                if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 147                    (listener)(event, window, cx)
 148                }
 149            }));
 150    }
 151
 152    /// Bind the given callback to the mouse down event for any button, during the bubble phase
 153    /// the imperative API equivalent to [`InteractiveElement::on_any_mouse_down`]
 154    ///
 155    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 156    pub fn on_any_mouse_down(
 157        &mut self,
 158        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 159    ) {
 160        self.mouse_down_listeners
 161            .push(Box::new(move |event, phase, hitbox, window, cx| {
 162                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
 163                    (listener)(event, window, cx)
 164                }
 165            }));
 166    }
 167
 168    /// Bind the given callback to the mouse up event for the given button, during the bubble phase
 169    /// the imperative API equivalent to [`InteractiveElement::on_mouse_up`]
 170    ///
 171    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 172    pub fn on_mouse_up(
 173        &mut self,
 174        button: MouseButton,
 175        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 176    ) {
 177        self.mouse_up_listeners
 178            .push(Box::new(move |event, phase, hitbox, window, cx| {
 179                if phase == DispatchPhase::Bubble
 180                    && event.button == button
 181                    && hitbox.is_hovered(window)
 182                {
 183                    (listener)(event, window, cx)
 184                }
 185            }));
 186    }
 187
 188    /// Bind the given callback to the mouse up event for any button, during the capture phase
 189    /// the imperative API equivalent to [`InteractiveElement::capture_any_mouse_up`]
 190    ///
 191    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 192    pub fn capture_any_mouse_up(
 193        &mut self,
 194        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 195    ) {
 196        self.mouse_up_listeners
 197            .push(Box::new(move |event, phase, hitbox, window, cx| {
 198                if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 199                    (listener)(event, window, cx)
 200                }
 201            }));
 202    }
 203
 204    /// Bind the given callback to the mouse up event for any button, during the bubble phase
 205    /// the imperative API equivalent to [`Interactivity::on_any_mouse_up`]
 206    ///
 207    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 208    pub fn on_any_mouse_up(
 209        &mut self,
 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 && hitbox.is_hovered(window) {
 215                    (listener)(event, window, cx)
 216                }
 217            }));
 218    }
 219
 220    /// Bind the given callback to the mouse down event, on any button, during the capture phase,
 221    /// when the mouse is outside of the bounds of this element.
 222    /// The imperative API equivalent to [`InteractiveElement::on_mouse_down_out`]
 223    ///
 224    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 225    pub fn on_mouse_down_out(
 226        &mut self,
 227        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 228    ) {
 229        self.mouse_down_listeners
 230            .push(Box::new(move |event, phase, hitbox, window, cx| {
 231                if phase == DispatchPhase::Capture && !hitbox.contains(&window.mouse_position()) {
 232                    (listener)(event, window, cx)
 233                }
 234            }));
 235    }
 236
 237    /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
 238    /// when the mouse is outside of the bounds of this element.
 239    /// The imperative API equivalent to [`InteractiveElement::on_mouse_up_out`]
 240    ///
 241    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 242    pub fn on_mouse_up_out(
 243        &mut self,
 244        button: MouseButton,
 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::Capture
 250                    && event.button == button
 251                    && !hitbox.is_hovered(window)
 252                {
 253                    (listener)(event, window, cx);
 254                }
 255            }));
 256    }
 257
 258    /// Bind the given callback to the mouse move event, during the bubble phase
 259    /// The imperative API equivalent to [`InteractiveElement::on_mouse_move`]
 260    ///
 261    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 262    pub fn on_mouse_move(
 263        &mut self,
 264        listener: impl Fn(&MouseMoveEvent, &mut Window, &mut App) + 'static,
 265    ) {
 266        self.mouse_move_listeners
 267            .push(Box::new(move |event, phase, hitbox, window, cx| {
 268                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
 269                    (listener)(event, window, cx);
 270                }
 271            }));
 272    }
 273
 274    /// Bind the given callback to the mouse drag event of the given type. Note that this
 275    /// will be called for all move events, inside or outside of this element, as long as the
 276    /// drag was started with this element under the mouse. Useful for implementing draggable
 277    /// UIs that don't conform to a drag and drop style interaction, like resizing.
 278    /// The imperative API equivalent to [`InteractiveElement::on_drag_move`]
 279    ///
 280    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 281    pub fn on_drag_move<T>(
 282        &mut self,
 283        listener: impl Fn(&DragMoveEvent<T>, &mut Window, &mut App) + 'static,
 284    ) where
 285        T: 'static,
 286    {
 287        self.mouse_move_listeners
 288            .push(Box::new(move |event, phase, hitbox, window, cx| {
 289                if phase == DispatchPhase::Capture {
 290                    if let Some(drag) = &cx.active_drag {
 291                        if drag.value.as_ref().type_id() == TypeId::of::<T>() {
 292                            (listener)(
 293                                &DragMoveEvent {
 294                                    event: event.clone(),
 295                                    bounds: hitbox.bounds,
 296                                    drag: PhantomData,
 297                                    dragged_item: Arc::clone(&drag.value),
 298                                },
 299                                window,
 300                                cx,
 301                            );
 302                        }
 303                    }
 304                }
 305            }));
 306    }
 307
 308    /// Bind the given callback to scroll wheel events during the bubble phase
 309    /// The imperative API equivalent to [`InteractiveElement::on_scroll_wheel`]
 310    ///
 311    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 312    pub fn on_scroll_wheel(
 313        &mut self,
 314        listener: impl Fn(&ScrollWheelEvent, &mut Window, &mut App) + 'static,
 315    ) {
 316        self.scroll_wheel_listeners
 317            .push(Box::new(move |event, phase, hitbox, window, cx| {
 318                if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
 319                    (listener)(event, window, cx);
 320                }
 321            }));
 322    }
 323
 324    /// Bind the given callback to an action dispatch during the capture phase
 325    /// The imperative API equivalent to [`InteractiveElement::capture_action`]
 326    ///
 327    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 328    pub fn capture_action<A: Action>(
 329        &mut self,
 330        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
 331    ) {
 332        self.action_listeners.push((
 333            TypeId::of::<A>(),
 334            Box::new(move |action, phase, window, cx| {
 335                let action = action.downcast_ref().unwrap();
 336                if phase == DispatchPhase::Capture {
 337                    (listener)(action, window, cx)
 338                } else {
 339                    cx.propagate();
 340                }
 341            }),
 342        ));
 343    }
 344
 345    /// Bind the given callback to an action dispatch during the bubble phase
 346    /// The imperative API equivalent to [`InteractiveElement::on_action`]
 347    ///
 348    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 349    pub fn on_action<A: Action>(&mut self, listener: impl Fn(&A, &mut Window, &mut App) + 'static) {
 350        self.action_listeners.push((
 351            TypeId::of::<A>(),
 352            Box::new(move |action, phase, window, cx| {
 353                let action = action.downcast_ref().unwrap();
 354                if phase == DispatchPhase::Bubble {
 355                    (listener)(action, window, cx)
 356                }
 357            }),
 358        ));
 359    }
 360
 361    /// Bind the given callback to an action dispatch, based on a dynamic action parameter
 362    /// instead of a type parameter. Useful for component libraries that want to expose
 363    /// action bindings to their users.
 364    /// The imperative API equivalent to [`InteractiveElement::on_boxed_action`]
 365    ///
 366    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 367    pub fn on_boxed_action(
 368        &mut self,
 369        action: &dyn Action,
 370        listener: impl Fn(&dyn Action, &mut Window, &mut App) + 'static,
 371    ) {
 372        let action = action.boxed_clone();
 373        self.action_listeners.push((
 374            (*action).type_id(),
 375            Box::new(move |_, phase, window, cx| {
 376                if phase == DispatchPhase::Bubble {
 377                    (listener)(&*action, window, cx)
 378                }
 379            }),
 380        ));
 381    }
 382
 383    /// Bind the given callback to key down events during the bubble phase
 384    /// The imperative API equivalent to [`InteractiveElement::on_key_down`]
 385    ///
 386    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 387    pub fn on_key_down(
 388        &mut self,
 389        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
 390    ) {
 391        self.key_down_listeners
 392            .push(Box::new(move |event, phase, window, cx| {
 393                if phase == DispatchPhase::Bubble {
 394                    (listener)(event, window, cx)
 395                }
 396            }));
 397    }
 398
 399    /// Bind the given callback to key down events during the capture phase
 400    /// The imperative API equivalent to [`InteractiveElement::capture_key_down`]
 401    ///
 402    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 403    pub fn capture_key_down(
 404        &mut self,
 405        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
 406    ) {
 407        self.key_down_listeners
 408            .push(Box::new(move |event, phase, window, cx| {
 409                if phase == DispatchPhase::Capture {
 410                    listener(event, window, cx)
 411                }
 412            }));
 413    }
 414
 415    /// Bind the given callback to key up events during the bubble phase
 416    /// The imperative API equivalent to [`InteractiveElement::on_key_up`]
 417    ///
 418    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 419    pub fn on_key_up(&mut self, listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static) {
 420        self.key_up_listeners
 421            .push(Box::new(move |event, phase, window, cx| {
 422                if phase == DispatchPhase::Bubble {
 423                    listener(event, window, cx)
 424                }
 425            }));
 426    }
 427
 428    /// Bind the given callback to key up events during the capture phase
 429    /// The imperative API equivalent to [`InteractiveElement::on_key_up`]
 430    ///
 431    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 432    pub fn capture_key_up(
 433        &mut self,
 434        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
 435    ) {
 436        self.key_up_listeners
 437            .push(Box::new(move |event, phase, window, cx| {
 438                if phase == DispatchPhase::Capture {
 439                    listener(event, window, cx)
 440                }
 441            }));
 442    }
 443
 444    /// Bind the given callback to modifiers changing events.
 445    /// The imperative API equivalent to [`InteractiveElement::on_modifiers_changed`]
 446    ///
 447    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 448    pub fn on_modifiers_changed(
 449        &mut self,
 450        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
 451    ) {
 452        self.modifiers_changed_listeners
 453            .push(Box::new(move |event, window, cx| {
 454                listener(event, window, cx)
 455            }));
 456    }
 457
 458    /// Bind the given callback to drop events of the given type, whether or not the drag started on this element
 459    /// The imperative API equivalent to [`InteractiveElement::on_drop`]
 460    ///
 461    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 462    pub fn on_drop<T: 'static>(&mut self, listener: impl Fn(&T, &mut Window, &mut App) + 'static) {
 463        self.drop_listeners.push((
 464            TypeId::of::<T>(),
 465            Box::new(move |dragged_value, window, cx| {
 466                listener(dragged_value.downcast_ref().unwrap(), window, cx);
 467            }),
 468        ));
 469    }
 470
 471    /// Use the given predicate to determine whether or not a drop event should be dispatched to this element
 472    /// The imperative API equivalent to [`InteractiveElement::can_drop`]
 473    pub fn can_drop(
 474        &mut self,
 475        predicate: impl Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static,
 476    ) {
 477        self.can_drop_predicate = Some(Box::new(predicate));
 478    }
 479
 480    /// Bind the given callback to click events of this element
 481    /// The imperative API equivalent to [`StatefulInteractiveElement::on_click`]
 482    ///
 483    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 484    pub fn on_click(&mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static)
 485    where
 486        Self: Sized,
 487    {
 488        self.click_listeners.push(Rc::new(move |event, window, cx| {
 489            listener(event, window, cx)
 490        }));
 491    }
 492
 493    /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
 494    /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
 495    /// the [`Self::on_drag_move`] API
 496    /// The imperative API equivalent to [`StatefulInteractiveElement::on_drag`]
 497    ///
 498    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 499    pub fn on_drag<T, W>(
 500        &mut self,
 501        value: T,
 502        constructor: impl Fn(&T, Point<Pixels>, &mut Window, &mut App) -> Entity<W> + 'static,
 503    ) where
 504        Self: Sized,
 505        T: 'static,
 506        W: 'static + Render,
 507    {
 508        debug_assert!(
 509            self.drag_listener.is_none(),
 510            "calling on_drag more than once on the same element is not supported"
 511        );
 512        self.drag_listener = Some((
 513            Arc::new(value),
 514            Box::new(move |value, offset, window, cx| {
 515                constructor(value.downcast_ref().unwrap(), offset, window, cx).into()
 516            }),
 517        ));
 518    }
 519
 520    /// Bind the given callback on the hover start and end events of this element. Note that the boolean
 521    /// passed to the callback is true when the hover starts and false when it ends.
 522    /// The imperative API equivalent to [`StatefulInteractiveElement::on_hover`]
 523    ///
 524    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 525    pub fn on_hover(&mut self, listener: impl Fn(&bool, &mut Window, &mut App) + 'static)
 526    where
 527        Self: Sized,
 528    {
 529        debug_assert!(
 530            self.hover_listener.is_none(),
 531            "calling on_hover more than once on the same element is not supported"
 532        );
 533        self.hover_listener = Some(Box::new(listener));
 534    }
 535
 536    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
 537    /// The imperative API equivalent to [`InteractiveElement::tooltip`]
 538    pub fn tooltip(&mut self, build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static)
 539    where
 540        Self: Sized,
 541    {
 542        debug_assert!(
 543            self.tooltip_builder.is_none(),
 544            "calling tooltip more than once on the same element is not supported"
 545        );
 546        self.tooltip_builder = Some(TooltipBuilder {
 547            build: Rc::new(build_tooltip),
 548            hoverable: false,
 549        });
 550    }
 551
 552    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
 553    /// The tooltip itself is also hoverable and won't disappear when the user moves the mouse into
 554    /// the tooltip. The imperative API equivalent to [`InteractiveElement::hoverable_tooltip`]
 555    pub fn hoverable_tooltip(
 556        &mut self,
 557        build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static,
 558    ) where
 559        Self: Sized,
 560    {
 561        debug_assert!(
 562            self.tooltip_builder.is_none(),
 563            "calling tooltip more than once on the same element is not supported"
 564        );
 565        self.tooltip_builder = Some(TooltipBuilder {
 566            build: Rc::new(build_tooltip),
 567            hoverable: true,
 568        });
 569    }
 570
 571    /// Block the mouse from all interactions with elements behind this element's hitbox. Typically
 572    /// `block_mouse_except_scroll` should be preferred.
 573    ///
 574    /// The imperative API equivalent to [`InteractiveElement::occlude`]
 575    pub fn occlude_mouse(&mut self) {
 576        self.hitbox_behavior = HitboxBehavior::BlockMouse;
 577    }
 578
 579    /// Set the bounds of this element as a window control area for the platform window.
 580    /// The imperative API equivalent to [`InteractiveElement::window_control_area`]
 581    pub fn window_control_area(&mut self, area: WindowControlArea) {
 582        self.window_control = Some(area);
 583    }
 584
 585    /// Block non-scroll mouse interactions with elements behind this element's hitbox. See
 586    /// [`Hitbox::is_hovered`] for details.
 587    ///
 588    /// The imperative API equivalent to [`InteractiveElement::block_mouse_except_scroll`]
 589    pub fn block_mouse_except_scroll(&mut self) {
 590        self.hitbox_behavior = HitboxBehavior::BlockMouseExceptScroll;
 591    }
 592}
 593
 594/// A trait for elements that want to use the standard GPUI event handlers that don't
 595/// require any state.
 596pub trait InteractiveElement: Sized {
 597    /// Retrieve the interactivity state associated with this element
 598    fn interactivity(&mut self) -> &mut Interactivity;
 599
 600    /// Assign this element to a group of elements that can be styled together
 601    fn group(mut self, group: impl Into<SharedString>) -> Self {
 602        self.interactivity().group = Some(group.into());
 603        self
 604    }
 605
 606    /// Assign this element an ID, so that it can be used with interactivity
 607    fn id(mut self, id: impl Into<ElementId>) -> Stateful<Self> {
 608        self.interactivity().element_id = Some(id.into());
 609
 610        Stateful { element: self }
 611    }
 612
 613    /// Track the focus state of the given focus handle on this element.
 614    /// If the focus handle is focused by the application, this element will
 615    /// apply its focused styles.
 616    fn track_focus(mut self, focus_handle: &FocusHandle) -> Self {
 617        self.interactivity().focusable = true;
 618        self.interactivity().tracked_focus_handle = Some(focus_handle.clone());
 619        self
 620    }
 621
 622    /// Set index of the tab stop order.
 623    fn tab_index(mut self, index: isize) -> Self {
 624        self.interactivity().focusable = true;
 625        self.interactivity().tab_index = Some(index);
 626        self
 627    }
 628
 629    /// Set the keymap context for this element. This will be used to determine
 630    /// which action to dispatch from the keymap.
 631    fn key_context<C, E>(mut self, key_context: C) -> Self
 632    where
 633        C: TryInto<KeyContext, Error = E>,
 634        E: Debug,
 635    {
 636        if let Some(key_context) = key_context.try_into().log_err() {
 637            self.interactivity().key_context = Some(key_context);
 638        }
 639        self
 640    }
 641
 642    /// Apply the given style to this element when the mouse hovers over it
 643    fn hover(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self {
 644        debug_assert!(
 645            self.interactivity().hover_style.is_none(),
 646            "hover style already set"
 647        );
 648        self.interactivity().hover_style = Some(Box::new(f(StyleRefinement::default())));
 649        self
 650    }
 651
 652    /// Apply the given style to this element when the mouse hovers over a group member
 653    fn group_hover(
 654        mut self,
 655        group_name: impl Into<SharedString>,
 656        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
 657    ) -> Self {
 658        self.interactivity().group_hover_style = Some(GroupStyle {
 659            group: group_name.into(),
 660            style: Box::new(f(StyleRefinement::default())),
 661        });
 662        self
 663    }
 664
 665    /// Bind the given callback to the mouse down event for the given mouse button,
 666    /// the fluent API equivalent to [`Interactivity::on_mouse_down`]
 667    ///
 668    /// See [`Context::listener`](crate::Context::listener) to get access to the view state from this callback.
 669    fn on_mouse_down(
 670        mut self,
 671        button: MouseButton,
 672        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 673    ) -> Self {
 674        self.interactivity().on_mouse_down(button, listener);
 675        self
 676    }
 677
 678    #[cfg(any(test, feature = "test-support"))]
 679    /// Set a key that can be used to look up this element's bounds
 680    /// in the [`VisualTestContext::debug_bounds`] map
 681    /// This is a noop in release builds
 682    fn debug_selector(mut self, f: impl FnOnce() -> String) -> Self {
 683        self.interactivity().debug_selector = Some(f());
 684        self
 685    }
 686
 687    #[cfg(not(any(test, feature = "test-support")))]
 688    /// Set a key that can be used to look up this element's bounds
 689    /// in the [`VisualTestContext::debug_bounds`] map
 690    /// This is a noop in release builds
 691    #[inline]
 692    fn debug_selector(self, _: impl FnOnce() -> String) -> Self {
 693        self
 694    }
 695
 696    /// Bind the given callback to the mouse down event for any button, during the capture phase
 697    /// the fluent API equivalent to [`Interactivity::capture_any_mouse_down`]
 698    ///
 699    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 700    fn capture_any_mouse_down(
 701        mut self,
 702        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 703    ) -> Self {
 704        self.interactivity().capture_any_mouse_down(listener);
 705        self
 706    }
 707
 708    /// Bind the given callback to the mouse down event for any button, during the capture phase
 709    /// the fluent API equivalent to [`Interactivity::on_any_mouse_down`]
 710    ///
 711    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 712    fn on_any_mouse_down(
 713        mut self,
 714        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 715    ) -> Self {
 716        self.interactivity().on_any_mouse_down(listener);
 717        self
 718    }
 719
 720    /// Bind the given callback to the mouse up event for the given button, during the bubble phase
 721    /// the fluent API equivalent to [`Interactivity::on_mouse_up`]
 722    ///
 723    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 724    fn on_mouse_up(
 725        mut self,
 726        button: MouseButton,
 727        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 728    ) -> Self {
 729        self.interactivity().on_mouse_up(button, listener);
 730        self
 731    }
 732
 733    /// Bind the given callback to the mouse up event for any button, during the capture phase
 734    /// the fluent API equivalent to [`Interactivity::capture_any_mouse_up`]
 735    ///
 736    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 737    fn capture_any_mouse_up(
 738        mut self,
 739        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 740    ) -> Self {
 741        self.interactivity().capture_any_mouse_up(listener);
 742        self
 743    }
 744
 745    /// Bind the given callback to the mouse down event, on any button, during the capture phase,
 746    /// when the mouse is outside of the bounds of this element.
 747    /// The fluent API equivalent to [`Interactivity::on_mouse_down_out`]
 748    ///
 749    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 750    fn on_mouse_down_out(
 751        mut self,
 752        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
 753    ) -> Self {
 754        self.interactivity().on_mouse_down_out(listener);
 755        self
 756    }
 757
 758    /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
 759    /// when the mouse is outside of the bounds of this element.
 760    /// The fluent API equivalent to [`Interactivity::on_mouse_up_out`]
 761    ///
 762    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 763    fn on_mouse_up_out(
 764        mut self,
 765        button: MouseButton,
 766        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
 767    ) -> Self {
 768        self.interactivity().on_mouse_up_out(button, listener);
 769        self
 770    }
 771
 772    /// Bind the given callback to the mouse move event, during the bubble phase
 773    /// The fluent API equivalent to [`Interactivity::on_mouse_move`]
 774    ///
 775    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 776    fn on_mouse_move(
 777        mut self,
 778        listener: impl Fn(&MouseMoveEvent, &mut Window, &mut App) + 'static,
 779    ) -> Self {
 780        self.interactivity().on_mouse_move(listener);
 781        self
 782    }
 783
 784    /// Bind the given callback to the mouse drag event of the given type. Note that this
 785    /// will be called for all move events, inside or outside of this element, as long as the
 786    /// drag was started with this element under the mouse. Useful for implementing draggable
 787    /// UIs that don't conform to a drag and drop style interaction, like resizing.
 788    /// The fluent API equivalent to [`Interactivity::on_drag_move`]
 789    ///
 790    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 791    fn on_drag_move<T: 'static>(
 792        mut self,
 793        listener: impl Fn(&DragMoveEvent<T>, &mut Window, &mut App) + 'static,
 794    ) -> Self {
 795        self.interactivity().on_drag_move(listener);
 796        self
 797    }
 798
 799    /// Bind the given callback to scroll wheel events during the bubble phase
 800    /// The fluent API equivalent to [`Interactivity::on_scroll_wheel`]
 801    ///
 802    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 803    fn on_scroll_wheel(
 804        mut self,
 805        listener: impl Fn(&ScrollWheelEvent, &mut Window, &mut App) + 'static,
 806    ) -> Self {
 807        self.interactivity().on_scroll_wheel(listener);
 808        self
 809    }
 810
 811    /// Capture the given action, before normal action dispatch can fire
 812    /// The fluent API equivalent to [`Interactivity::on_scroll_wheel`]
 813    ///
 814    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 815    fn capture_action<A: Action>(
 816        mut self,
 817        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
 818    ) -> Self {
 819        self.interactivity().capture_action(listener);
 820        self
 821    }
 822
 823    /// Bind the given callback to an action dispatch during the bubble phase
 824    /// The fluent API equivalent to [`Interactivity::on_action`]
 825    ///
 826    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 827    fn on_action<A: Action>(
 828        mut self,
 829        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
 830    ) -> Self {
 831        self.interactivity().on_action(listener);
 832        self
 833    }
 834
 835    /// Bind the given callback to an action dispatch, based on a dynamic action parameter
 836    /// instead of a type parameter. Useful for component libraries that want to expose
 837    /// action bindings to their users.
 838    /// The fluent API equivalent to [`Interactivity::on_boxed_action`]
 839    ///
 840    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 841    fn on_boxed_action(
 842        mut self,
 843        action: &dyn Action,
 844        listener: impl Fn(&dyn Action, &mut Window, &mut App) + 'static,
 845    ) -> Self {
 846        self.interactivity().on_boxed_action(action, listener);
 847        self
 848    }
 849
 850    /// Bind the given callback to key down events during the bubble phase
 851    /// The fluent API equivalent to [`Interactivity::on_key_down`]
 852    ///
 853    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 854    fn on_key_down(
 855        mut self,
 856        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
 857    ) -> Self {
 858        self.interactivity().on_key_down(listener);
 859        self
 860    }
 861
 862    /// Bind the given callback to key down events during the capture phase
 863    /// The fluent API equivalent to [`Interactivity::capture_key_down`]
 864    ///
 865    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 866    fn capture_key_down(
 867        mut self,
 868        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
 869    ) -> Self {
 870        self.interactivity().capture_key_down(listener);
 871        self
 872    }
 873
 874    /// Bind the given callback to key up events during the bubble phase
 875    /// The fluent API equivalent to [`Interactivity::on_key_up`]
 876    ///
 877    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 878    fn on_key_up(
 879        mut self,
 880        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
 881    ) -> Self {
 882        self.interactivity().on_key_up(listener);
 883        self
 884    }
 885
 886    /// Bind the given callback to key up events during the capture phase
 887    /// The fluent API equivalent to [`Interactivity::capture_key_up`]
 888    ///
 889    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 890    fn capture_key_up(
 891        mut self,
 892        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
 893    ) -> Self {
 894        self.interactivity().capture_key_up(listener);
 895        self
 896    }
 897
 898    /// Bind the given callback to modifiers changing events.
 899    /// The fluent API equivalent to [`Interactivity::on_modifiers_changed`]
 900    ///
 901    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 902    fn on_modifiers_changed(
 903        mut self,
 904        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
 905    ) -> Self {
 906        self.interactivity().on_modifiers_changed(listener);
 907        self
 908    }
 909
 910    /// Apply the given style when the given data type is dragged over this element
 911    fn drag_over<S: 'static>(
 912        mut self,
 913        f: impl 'static + Fn(StyleRefinement, &S, &mut Window, &mut App) -> StyleRefinement,
 914    ) -> Self {
 915        self.interactivity().drag_over_styles.push((
 916            TypeId::of::<S>(),
 917            Box::new(move |currently_dragged: &dyn Any, window, cx| {
 918                f(
 919                    StyleRefinement::default(),
 920                    currently_dragged.downcast_ref::<S>().unwrap(),
 921                    window,
 922                    cx,
 923                )
 924            }),
 925        ));
 926        self
 927    }
 928
 929    /// Apply the given style when the given data type is dragged over this element's group
 930    fn group_drag_over<S: 'static>(
 931        mut self,
 932        group_name: impl Into<SharedString>,
 933        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
 934    ) -> Self {
 935        self.interactivity().group_drag_over_styles.push((
 936            TypeId::of::<S>(),
 937            GroupStyle {
 938                group: group_name.into(),
 939                style: Box::new(f(StyleRefinement::default())),
 940            },
 941        ));
 942        self
 943    }
 944
 945    /// Bind the given callback to drop events of the given type, whether or not the drag started on this element
 946    /// The fluent API equivalent to [`Interactivity::on_drop`]
 947    ///
 948    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
 949    fn on_drop<T: 'static>(
 950        mut self,
 951        listener: impl Fn(&T, &mut Window, &mut App) + 'static,
 952    ) -> Self {
 953        self.interactivity().on_drop(listener);
 954        self
 955    }
 956
 957    /// Use the given predicate to determine whether or not a drop event should be dispatched to this element
 958    /// The fluent API equivalent to [`Interactivity::can_drop`]
 959    fn can_drop(
 960        mut self,
 961        predicate: impl Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static,
 962    ) -> Self {
 963        self.interactivity().can_drop(predicate);
 964        self
 965    }
 966
 967    /// Block the mouse from all interactions with elements behind this element's hitbox. Typically
 968    /// `block_mouse_except_scroll` should be preferred.
 969    /// The fluent API equivalent to [`Interactivity::occlude_mouse`]
 970    fn occlude(mut self) -> Self {
 971        self.interactivity().occlude_mouse();
 972        self
 973    }
 974
 975    /// Set the bounds of this element as a window control area for the platform window.
 976    /// The fluent API equivalent to [`Interactivity::window_control_area`]
 977    fn window_control_area(mut self, area: WindowControlArea) -> Self {
 978        self.interactivity().window_control_area(area);
 979        self
 980    }
 981
 982    /// Block non-scroll mouse interactions with elements behind this element's hitbox. See
 983    /// [`Hitbox::is_hovered`] for details.
 984    ///
 985    /// The fluent API equivalent to [`Interactivity::block_mouse_except_scroll`]
 986    fn block_mouse_except_scroll(mut self) -> Self {
 987        self.interactivity().block_mouse_except_scroll();
 988        self
 989    }
 990
 991    /// Set the given styles to be applied when this element, specifically, is focused.
 992    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
 993    fn focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
 994    where
 995        Self: Sized,
 996    {
 997        self.interactivity().focus_style = Some(Box::new(f(StyleRefinement::default())));
 998        self
 999    }
1000
1001    /// Set the given styles to be applied when this element is inside another element that is focused.
1002    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
1003    fn in_focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1004    where
1005        Self: Sized,
1006    {
1007        self.interactivity().in_focus_style = Some(Box::new(f(StyleRefinement::default())));
1008        self
1009    }
1010}
1011
1012/// A trait for elements that want to use the standard GPUI interactivity features
1013/// that require state.
1014pub trait StatefulInteractiveElement: InteractiveElement {
1015    /// Set this element to focusable.
1016    fn focusable(mut self) -> Self {
1017        self.interactivity().focusable = true;
1018        self
1019    }
1020
1021    /// Set the overflow x and y to scroll.
1022    fn overflow_scroll(mut self) -> Self {
1023        self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
1024        self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
1025        self
1026    }
1027
1028    /// Set the overflow x to scroll.
1029    fn overflow_x_scroll(mut self) -> Self {
1030        self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
1031        self
1032    }
1033
1034    /// Set the overflow y to scroll.
1035    fn overflow_y_scroll(mut self) -> Self {
1036        self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
1037        self
1038    }
1039
1040    /// Track the scroll state of this element with the given handle.
1041    fn track_scroll(mut self, scroll_handle: &ScrollHandle) -> Self {
1042        self.interactivity().tracked_scroll_handle = Some(scroll_handle.clone());
1043        self
1044    }
1045
1046    /// Track the scroll state of this element with the given handle.
1047    fn anchor_scroll(mut self, scroll_anchor: Option<ScrollAnchor>) -> Self {
1048        self.interactivity().scroll_anchor = scroll_anchor;
1049        self
1050    }
1051
1052    /// Set the given styles to be applied when this element is active.
1053    fn active(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1054    where
1055        Self: Sized,
1056    {
1057        self.interactivity().active_style = Some(Box::new(f(StyleRefinement::default())));
1058        self
1059    }
1060
1061    /// Set the given styles to be applied when this element's group is active.
1062    fn group_active(
1063        mut self,
1064        group_name: impl Into<SharedString>,
1065        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
1066    ) -> Self
1067    where
1068        Self: Sized,
1069    {
1070        self.interactivity().group_active_style = Some(GroupStyle {
1071            group: group_name.into(),
1072            style: Box::new(f(StyleRefinement::default())),
1073        });
1074        self
1075    }
1076
1077    /// Bind the given callback to click events of this element
1078    /// The fluent API equivalent to [`Interactivity::on_click`]
1079    ///
1080    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1081    fn on_click(mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static) -> Self
1082    where
1083        Self: Sized,
1084    {
1085        self.interactivity().on_click(listener);
1086        self
1087    }
1088
1089    /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
1090    /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
1091    /// the [`Self::on_drag_move`] API.
1092    /// The callback also has access to the offset of triggering click from the origin of parent element.
1093    /// The fluent API equivalent to [`Interactivity::on_drag`]
1094    ///
1095    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1096    fn on_drag<T, W>(
1097        mut self,
1098        value: T,
1099        constructor: impl Fn(&T, Point<Pixels>, &mut Window, &mut App) -> Entity<W> + 'static,
1100    ) -> Self
1101    where
1102        Self: Sized,
1103        T: 'static,
1104        W: 'static + Render,
1105    {
1106        self.interactivity().on_drag(value, constructor);
1107        self
1108    }
1109
1110    /// Bind the given callback on the hover start and end events of this element. Note that the boolean
1111    /// passed to the callback is true when the hover starts and false when it ends.
1112    /// The fluent API equivalent to [`Interactivity::on_hover`]
1113    ///
1114    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1115    fn on_hover(mut self, listener: impl Fn(&bool, &mut Window, &mut App) + 'static) -> Self
1116    where
1117        Self: Sized,
1118    {
1119        self.interactivity().on_hover(listener);
1120        self
1121    }
1122
1123    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
1124    /// The fluent API equivalent to [`Interactivity::tooltip`]
1125    fn tooltip(mut self, build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static) -> Self
1126    where
1127        Self: Sized,
1128    {
1129        self.interactivity().tooltip(build_tooltip);
1130        self
1131    }
1132
1133    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
1134    /// The tooltip itself is also hoverable and won't disappear when the user moves the mouse into
1135    /// the tooltip. The fluent API equivalent to [`Interactivity::hoverable_tooltip`]
1136    fn hoverable_tooltip(
1137        mut self,
1138        build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static,
1139    ) -> Self
1140    where
1141        Self: Sized,
1142    {
1143        self.interactivity().hoverable_tooltip(build_tooltip);
1144        self
1145    }
1146}
1147
1148pub(crate) type MouseDownListener =
1149    Box<dyn Fn(&MouseDownEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1150pub(crate) type MouseUpListener =
1151    Box<dyn Fn(&MouseUpEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1152
1153pub(crate) type MouseMoveListener =
1154    Box<dyn Fn(&MouseMoveEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1155
1156pub(crate) type ScrollWheelListener =
1157    Box<dyn Fn(&ScrollWheelEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1158
1159pub(crate) type ClickListener = Rc<dyn Fn(&ClickEvent, &mut Window, &mut App) + 'static>;
1160
1161pub(crate) type DragListener =
1162    Box<dyn Fn(&dyn Any, Point<Pixels>, &mut Window, &mut App) -> AnyView + 'static>;
1163
1164type DropListener = Box<dyn Fn(&dyn Any, &mut Window, &mut App) + 'static>;
1165
1166type CanDropPredicate = Box<dyn Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static>;
1167
1168pub(crate) struct TooltipBuilder {
1169    build: Rc<dyn Fn(&mut Window, &mut App) -> AnyView + 'static>,
1170    hoverable: bool,
1171}
1172
1173pub(crate) type KeyDownListener =
1174    Box<dyn Fn(&KeyDownEvent, DispatchPhase, &mut Window, &mut App) + 'static>;
1175
1176pub(crate) type KeyUpListener =
1177    Box<dyn Fn(&KeyUpEvent, DispatchPhase, &mut Window, &mut App) + 'static>;
1178
1179pub(crate) type ModifiersChangedListener =
1180    Box<dyn Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static>;
1181
1182pub(crate) type ActionListener =
1183    Box<dyn Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
1184
1185/// Construct a new [`Div`] element
1186#[track_caller]
1187pub fn div() -> Div {
1188    Div {
1189        interactivity: Interactivity::new(),
1190        children: SmallVec::default(),
1191        prepaint_listener: None,
1192        image_cache: None,
1193    }
1194}
1195
1196/// A [`Div`] element, the all-in-one element for building complex UIs in GPUI
1197pub struct Div {
1198    interactivity: Interactivity,
1199    children: SmallVec<[AnyElement; 2]>,
1200    prepaint_listener: Option<Box<dyn Fn(Vec<Bounds<Pixels>>, &mut Window, &mut App) + 'static>>,
1201    image_cache: Option<Box<dyn ImageCacheProvider>>,
1202}
1203
1204impl Div {
1205    /// Add a listener to be called when the children of this `Div` are prepainted.
1206    /// This allows you to store the [`Bounds`] of the children for later use.
1207    pub fn on_children_prepainted(
1208        mut self,
1209        listener: impl Fn(Vec<Bounds<Pixels>>, &mut Window, &mut App) + 'static,
1210    ) -> Self {
1211        self.prepaint_listener = Some(Box::new(listener));
1212        self
1213    }
1214
1215    /// Add an image cache at the location of this div in the element tree.
1216    pub fn image_cache(mut self, cache: impl ImageCacheProvider) -> Self {
1217        self.image_cache = Some(Box::new(cache));
1218        self
1219    }
1220}
1221
1222/// A frame state for a `Div` element, which contains layout IDs for its children.
1223///
1224/// This struct is used internally by the `Div` element to manage the layout state of its children
1225/// during the UI update cycle. It holds a small vector of `LayoutId` values, each corresponding to
1226/// a child element of the `Div`. These IDs are used to query the layout engine for the computed
1227/// bounds of the children after the layout phase is complete.
1228pub struct DivFrameState {
1229    child_layout_ids: SmallVec<[LayoutId; 2]>,
1230}
1231
1232/// Interactivity state displayed an manipulated in the inspector.
1233#[derive(Clone)]
1234pub struct DivInspectorState {
1235    /// The inspected element's base style. This is used for both inspecting and modifying the
1236    /// state. In the future it will make sense to separate the read and write, possibly tracking
1237    /// the modifications.
1238    #[cfg(any(feature = "inspector", debug_assertions))]
1239    pub base_style: Box<StyleRefinement>,
1240    /// Inspects the bounds of the element.
1241    pub bounds: Bounds<Pixels>,
1242    /// Size of the children of the element, or `bounds.size` if it has no children.
1243    pub content_size: Size<Pixels>,
1244}
1245
1246impl Styled for Div {
1247    fn style(&mut self) -> &mut StyleRefinement {
1248        &mut self.interactivity.base_style
1249    }
1250}
1251
1252impl InteractiveElement for Div {
1253    fn interactivity(&mut self) -> &mut Interactivity {
1254        &mut self.interactivity
1255    }
1256}
1257
1258impl ParentElement for Div {
1259    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
1260        self.children.extend(elements)
1261    }
1262}
1263
1264impl Element for Div {
1265    type RequestLayoutState = DivFrameState;
1266    type PrepaintState = Option<Hitbox>;
1267
1268    fn id(&self) -> Option<ElementId> {
1269        self.interactivity.element_id.clone()
1270    }
1271
1272    fn source_location(&self) -> Option<&'static std::panic::Location<'static>> {
1273        self.interactivity.source_location()
1274    }
1275
1276    fn request_layout(
1277        &mut self,
1278        global_id: Option<&GlobalElementId>,
1279        inspector_id: Option<&InspectorElementId>,
1280        window: &mut Window,
1281        cx: &mut App,
1282    ) -> (LayoutId, Self::RequestLayoutState) {
1283        let mut child_layout_ids = SmallVec::new();
1284        let image_cache = self
1285            .image_cache
1286            .as_mut()
1287            .map(|provider| provider.provide(window, cx));
1288
1289        let layout_id = window.with_image_cache(image_cache, |window| {
1290            self.interactivity.request_layout(
1291                global_id,
1292                inspector_id,
1293                window,
1294                cx,
1295                |style, window, cx| {
1296                    window.with_text_style(style.text_style().cloned(), |window| {
1297                        child_layout_ids = self
1298                            .children
1299                            .iter_mut()
1300                            .map(|child| child.request_layout(window, cx))
1301                            .collect::<SmallVec<_>>();
1302                        window.request_layout(style, child_layout_ids.iter().copied(), cx)
1303                    })
1304                },
1305            )
1306        });
1307
1308        (layout_id, DivFrameState { child_layout_ids })
1309    }
1310
1311    fn prepaint(
1312        &mut self,
1313        global_id: Option<&GlobalElementId>,
1314        inspector_id: Option<&InspectorElementId>,
1315        bounds: Bounds<Pixels>,
1316        request_layout: &mut Self::RequestLayoutState,
1317        window: &mut Window,
1318        cx: &mut App,
1319    ) -> Option<Hitbox> {
1320        if let Some(global_id) = global_id
1321            && global_id.0.ends_with(&["open-router-container".into()])
1322        {
1323            println!("open-router-container bounds = {:?}", bounds)
1324        }
1325        if let Some(global_id) = global_id
1326            && global_id.0.ends_with(&["api-key-editor".into()])
1327        {
1328            println!("api-key-editor bounds = {:?}", bounds)
1329        }
1330
1331        let has_prepaint_listener = self.prepaint_listener.is_some();
1332        let mut children_bounds = Vec::with_capacity(if has_prepaint_listener {
1333            request_layout.child_layout_ids.len()
1334        } else {
1335            0
1336        });
1337
1338        let mut child_min = point(Pixels::MAX, Pixels::MAX);
1339        let mut child_max = Point::default();
1340        if let Some(handle) = self.interactivity.scroll_anchor.as_ref() {
1341            *handle.last_origin.borrow_mut() = bounds.origin - window.element_offset();
1342        }
1343        let content_size = if request_layout.child_layout_ids.is_empty() {
1344            bounds.size
1345        } else if let Some(scroll_handle) = self.interactivity.tracked_scroll_handle.as_ref() {
1346            let mut state = scroll_handle.0.borrow_mut();
1347            state.child_bounds = Vec::with_capacity(request_layout.child_layout_ids.len());
1348            for child_layout_id in &request_layout.child_layout_ids {
1349                let child_bounds = window.layout_bounds(*child_layout_id);
1350                child_min = child_min.min(&child_bounds.origin);
1351                child_max = child_max.max(&child_bounds.bottom_right());
1352                state.child_bounds.push(child_bounds);
1353            }
1354            (child_max - child_min).into()
1355        } else {
1356            for child_layout_id in &request_layout.child_layout_ids {
1357                let child_bounds = window.layout_bounds(*child_layout_id);
1358                child_min = child_min.min(&child_bounds.origin);
1359                child_max = child_max.max(&child_bounds.bottom_right());
1360
1361                if has_prepaint_listener {
1362                    children_bounds.push(child_bounds);
1363                }
1364            }
1365            (child_max - child_min).into()
1366        };
1367
1368        self.interactivity.prepaint(
1369            global_id,
1370            inspector_id,
1371            bounds,
1372            content_size,
1373            window,
1374            cx,
1375            |_style, scroll_offset, hitbox, window, cx| {
1376                window.with_element_offset(scroll_offset, |window| {
1377                    for child in &mut self.children {
1378                        child.prepaint(window, cx);
1379                    }
1380                });
1381
1382                if let Some(listener) = self.prepaint_listener.as_ref() {
1383                    listener(children_bounds, window, cx);
1384                }
1385
1386                hitbox
1387            },
1388        )
1389    }
1390
1391    fn paint(
1392        &mut self,
1393        global_id: Option<&GlobalElementId>,
1394        inspector_id: Option<&InspectorElementId>,
1395        bounds: Bounds<Pixels>,
1396        _request_layout: &mut Self::RequestLayoutState,
1397        hitbox: &mut Option<Hitbox>,
1398        window: &mut Window,
1399        cx: &mut App,
1400    ) {
1401        let image_cache = self
1402            .image_cache
1403            .as_mut()
1404            .map(|provider| provider.provide(window, cx));
1405
1406        window.with_image_cache(image_cache, |window| {
1407            self.interactivity.paint(
1408                global_id,
1409                inspector_id,
1410                bounds,
1411                hitbox.as_ref(),
1412                window,
1413                cx,
1414                |_style, window, cx| {
1415                    for child in &mut self.children {
1416                        child.paint(window, cx);
1417                    }
1418                },
1419            )
1420        });
1421    }
1422}
1423
1424impl IntoElement for Div {
1425    type Element = Self;
1426
1427    fn into_element(self) -> Self::Element {
1428        self
1429    }
1430}
1431
1432/// The interactivity struct. Powers all of the general-purpose
1433/// interactivity in the `Div` element.
1434#[derive(Default)]
1435pub struct Interactivity {
1436    /// The element ID of the element. In id is required to support a stateful subset of the interactivity such as on_click.
1437    pub element_id: Option<ElementId>,
1438    /// Whether the element was clicked. This will only be present after layout.
1439    pub active: Option<bool>,
1440    /// Whether the element was hovered. This will only be present after paint if an hitbox
1441    /// was created for the interactive element.
1442    pub hovered: Option<bool>,
1443    pub(crate) tooltip_id: Option<TooltipId>,
1444    pub(crate) content_size: Size<Pixels>,
1445    pub(crate) key_context: Option<KeyContext>,
1446    pub(crate) focusable: bool,
1447    pub(crate) tracked_focus_handle: Option<FocusHandle>,
1448    pub(crate) tracked_scroll_handle: Option<ScrollHandle>,
1449    pub(crate) scroll_anchor: Option<ScrollAnchor>,
1450    pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
1451    pub(crate) group: Option<SharedString>,
1452    /// The base style of the element, before any modifications are applied
1453    /// by focus, active, etc.
1454    pub base_style: Box<StyleRefinement>,
1455    pub(crate) focus_style: Option<Box<StyleRefinement>>,
1456    pub(crate) in_focus_style: Option<Box<StyleRefinement>>,
1457    pub(crate) hover_style: Option<Box<StyleRefinement>>,
1458    pub(crate) group_hover_style: Option<GroupStyle>,
1459    pub(crate) active_style: Option<Box<StyleRefinement>>,
1460    pub(crate) group_active_style: Option<GroupStyle>,
1461    pub(crate) drag_over_styles: Vec<(
1462        TypeId,
1463        Box<dyn Fn(&dyn Any, &mut Window, &mut App) -> StyleRefinement>,
1464    )>,
1465    pub(crate) group_drag_over_styles: Vec<(TypeId, GroupStyle)>,
1466    pub(crate) mouse_down_listeners: Vec<MouseDownListener>,
1467    pub(crate) mouse_up_listeners: Vec<MouseUpListener>,
1468    pub(crate) mouse_move_listeners: Vec<MouseMoveListener>,
1469    pub(crate) scroll_wheel_listeners: Vec<ScrollWheelListener>,
1470    pub(crate) key_down_listeners: Vec<KeyDownListener>,
1471    pub(crate) key_up_listeners: Vec<KeyUpListener>,
1472    pub(crate) modifiers_changed_listeners: Vec<ModifiersChangedListener>,
1473    pub(crate) action_listeners: Vec<(TypeId, ActionListener)>,
1474    pub(crate) drop_listeners: Vec<(TypeId, DropListener)>,
1475    pub(crate) can_drop_predicate: Option<CanDropPredicate>,
1476    pub(crate) click_listeners: Vec<ClickListener>,
1477    pub(crate) drag_listener: Option<(Arc<dyn Any>, DragListener)>,
1478    pub(crate) hover_listener: Option<Box<dyn Fn(&bool, &mut Window, &mut App)>>,
1479    pub(crate) tooltip_builder: Option<TooltipBuilder>,
1480    pub(crate) window_control: Option<WindowControlArea>,
1481    pub(crate) hitbox_behavior: HitboxBehavior,
1482    pub(crate) tab_index: Option<isize>,
1483
1484    #[cfg(any(feature = "inspector", debug_assertions))]
1485    pub(crate) source_location: Option<&'static core::panic::Location<'static>>,
1486
1487    #[cfg(any(test, feature = "test-support"))]
1488    pub(crate) debug_selector: Option<String>,
1489}
1490
1491impl Interactivity {
1492    /// Layout this element according to this interactivity state's configured styles
1493    pub fn request_layout(
1494        &mut self,
1495        global_id: Option<&GlobalElementId>,
1496        _inspector_id: Option<&InspectorElementId>,
1497        window: &mut Window,
1498        cx: &mut App,
1499        f: impl FnOnce(Style, &mut Window, &mut App) -> LayoutId,
1500    ) -> LayoutId {
1501        #[cfg(any(feature = "inspector", debug_assertions))]
1502        window.with_inspector_state(
1503            _inspector_id,
1504            cx,
1505            |inspector_state: &mut Option<DivInspectorState>, _window| {
1506                if let Some(inspector_state) = inspector_state {
1507                    self.base_style = inspector_state.base_style.clone();
1508                } else {
1509                    *inspector_state = Some(DivInspectorState {
1510                        base_style: self.base_style.clone(),
1511                        bounds: Default::default(),
1512                        content_size: Default::default(),
1513                    })
1514                }
1515            },
1516        );
1517
1518        window.with_optional_element_state::<InteractiveElementState, _>(
1519            global_id,
1520            |element_state, window| {
1521                let mut element_state =
1522                    element_state.map(|element_state| element_state.unwrap_or_default());
1523
1524                if let Some(element_state) = element_state.as_ref() {
1525                    if cx.has_active_drag() {
1526                        if let Some(pending_mouse_down) = element_state.pending_mouse_down.as_ref()
1527                        {
1528                            *pending_mouse_down.borrow_mut() = None;
1529                        }
1530                        if let Some(clicked_state) = element_state.clicked_state.as_ref() {
1531                            *clicked_state.borrow_mut() = ElementClickedState::default();
1532                        }
1533                    }
1534                }
1535
1536                // Ensure we store a focus handle in our element state if we're focusable.
1537                // If there's an explicit focus handle we're tracking, use that. Otherwise
1538                // create a new handle and store it in the element state, which lives for as
1539                // as frames contain an element with this id.
1540                if self.focusable && self.tracked_focus_handle.is_none() {
1541                    if let Some(element_state) = element_state.as_mut() {
1542                        let mut handle = element_state
1543                            .focus_handle
1544                            .get_or_insert_with(|| cx.focus_handle())
1545                            .clone()
1546                            .tab_stop(false);
1547
1548                        if let Some(index) = self.tab_index {
1549                            handle = handle.tab_index(index).tab_stop(true);
1550                        }
1551
1552                        self.tracked_focus_handle = Some(handle);
1553                    }
1554                }
1555
1556                if let Some(scroll_handle) = self.tracked_scroll_handle.as_ref() {
1557                    self.scroll_offset = Some(scroll_handle.0.borrow().offset.clone());
1558                } else if self.base_style.overflow.x == Some(Overflow::Scroll)
1559                    || self.base_style.overflow.y == Some(Overflow::Scroll)
1560                {
1561                    if let Some(element_state) = element_state.as_mut() {
1562                        self.scroll_offset = Some(
1563                            element_state
1564                                .scroll_offset
1565                                .get_or_insert_with(Rc::default)
1566                                .clone(),
1567                        );
1568                    }
1569                }
1570
1571                let style = self.compute_style_internal(None, element_state.as_mut(), window, cx);
1572                let layout_id = f(style, window, cx);
1573                (layout_id, element_state)
1574            },
1575        )
1576    }
1577
1578    /// Commit the bounds of this element according to this interactivity state's configured styles.
1579    pub fn prepaint<R>(
1580        &mut self,
1581        global_id: Option<&GlobalElementId>,
1582        _inspector_id: Option<&InspectorElementId>,
1583        bounds: Bounds<Pixels>,
1584        content_size: Size<Pixels>,
1585        window: &mut Window,
1586        cx: &mut App,
1587        f: impl FnOnce(&Style, Point<Pixels>, Option<Hitbox>, &mut Window, &mut App) -> R,
1588    ) -> R {
1589        self.content_size = content_size;
1590
1591        #[cfg(any(feature = "inspector", debug_assertions))]
1592        window.with_inspector_state(
1593            _inspector_id,
1594            cx,
1595            |inspector_state: &mut Option<DivInspectorState>, _window| {
1596                if let Some(inspector_state) = inspector_state {
1597                    inspector_state.bounds = bounds;
1598                    inspector_state.content_size = content_size;
1599                }
1600            },
1601        );
1602
1603        if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
1604            window.set_focus_handle(focus_handle, cx);
1605        }
1606        window.with_optional_element_state::<InteractiveElementState, _>(
1607            global_id,
1608            |element_state, window| {
1609                let mut element_state =
1610                    element_state.map(|element_state| element_state.unwrap_or_default());
1611                let style = self.compute_style_internal(None, element_state.as_mut(), window, cx);
1612
1613                if let Some(element_state) = element_state.as_mut() {
1614                    if let Some(clicked_state) = element_state.clicked_state.as_ref() {
1615                        let clicked_state = clicked_state.borrow();
1616                        self.active = Some(clicked_state.element);
1617                    }
1618                    if let Some(active_tooltip) = element_state.active_tooltip.as_ref() {
1619                        if self.tooltip_builder.is_some() {
1620                            self.tooltip_id = set_tooltip_on_window(active_tooltip, window);
1621                        } else {
1622                            // If there is no longer a tooltip builder, remove the active tooltip.
1623                            element_state.active_tooltip.take();
1624                        }
1625                    }
1626                }
1627
1628                window.with_text_style(style.text_style().cloned(), |window| {
1629                    window.with_content_mask(
1630                        style.overflow_mask(bounds, window.rem_size()),
1631                        |window| {
1632                            let hitbox = if self.should_insert_hitbox(&style, window, cx) {
1633                                Some(window.insert_hitbox(bounds, self.hitbox_behavior))
1634                            } else {
1635                                None
1636                            };
1637
1638                            let scroll_offset =
1639                                self.clamp_scroll_position(bounds, &style, window, cx);
1640                            let result = f(&style, scroll_offset, hitbox, window, cx);
1641                            (result, element_state)
1642                        },
1643                    )
1644                })
1645            },
1646        )
1647    }
1648
1649    fn should_insert_hitbox(&self, style: &Style, window: &Window, cx: &App) -> bool {
1650        self.hitbox_behavior != HitboxBehavior::Normal
1651            || self.window_control.is_some()
1652            || style.mouse_cursor.is_some()
1653            || self.group.is_some()
1654            || self.scroll_offset.is_some()
1655            || self.tracked_focus_handle.is_some()
1656            || self.hover_style.is_some()
1657            || self.group_hover_style.is_some()
1658            || self.hover_listener.is_some()
1659            || !self.mouse_up_listeners.is_empty()
1660            || !self.mouse_down_listeners.is_empty()
1661            || !self.mouse_move_listeners.is_empty()
1662            || !self.click_listeners.is_empty()
1663            || !self.scroll_wheel_listeners.is_empty()
1664            || self.drag_listener.is_some()
1665            || !self.drop_listeners.is_empty()
1666            || self.tooltip_builder.is_some()
1667            || window.is_inspector_picking(cx)
1668    }
1669
1670    fn clamp_scroll_position(
1671        &self,
1672        bounds: Bounds<Pixels>,
1673        style: &Style,
1674        window: &mut Window,
1675        _cx: &mut App,
1676    ) -> Point<Pixels> {
1677        fn round_to_two_decimals(pixels: Pixels) -> Pixels {
1678            const ROUNDING_FACTOR: f32 = 100.0;
1679            (pixels * ROUNDING_FACTOR).round() / ROUNDING_FACTOR
1680        }
1681
1682        if let Some(scroll_offset) = self.scroll_offset.as_ref() {
1683            let mut scroll_to_bottom = false;
1684            let mut tracked_scroll_handle = self
1685                .tracked_scroll_handle
1686                .as_ref()
1687                .map(|handle| handle.0.borrow_mut());
1688            if let Some(mut scroll_handle_state) = tracked_scroll_handle.as_deref_mut() {
1689                scroll_handle_state.overflow = style.overflow;
1690                scroll_to_bottom = mem::take(&mut scroll_handle_state.scroll_to_bottom);
1691            }
1692
1693            let rem_size = window.rem_size();
1694            let padding = style.padding.to_pixels(bounds.size.into(), rem_size);
1695            let padding_size = size(padding.left + padding.right, padding.top + padding.bottom);
1696            // The floating point values produced by Taffy and ours often vary
1697            // slightly after ~5 decimal places. This can lead to cases where after
1698            // subtracting these, the container becomes scrollable for less than
1699            // 0.00000x pixels. As we generally don't benefit from a precision that
1700            // high for the maximum scroll, we round the scroll max to 2 decimal
1701            // places here.
1702            let padded_content_size = self.content_size + padding_size;
1703            let scroll_max = (padded_content_size - bounds.size)
1704                .map(round_to_two_decimals)
1705                .max(&Default::default());
1706            // Clamp scroll offset in case scroll max is smaller now (e.g., if children
1707            // were removed or the bounds became larger).
1708            let mut scroll_offset = scroll_offset.borrow_mut();
1709
1710            scroll_offset.x = scroll_offset.x.clamp(-scroll_max.width, px(0.));
1711            if scroll_to_bottom {
1712                scroll_offset.y = -scroll_max.height;
1713            } else {
1714                scroll_offset.y = scroll_offset.y.clamp(-scroll_max.height, px(0.));
1715            }
1716
1717            if let Some(mut scroll_handle_state) = tracked_scroll_handle {
1718                scroll_handle_state.max_offset = scroll_max;
1719                scroll_handle_state.bounds = bounds;
1720            }
1721
1722            *scroll_offset
1723        } else {
1724            Point::default()
1725        }
1726    }
1727
1728    /// Paint this element according to this interactivity state's configured styles
1729    /// and bind the element's mouse and keyboard events.
1730    ///
1731    /// content_size is the size of the content of the element, which may be larger than the
1732    /// element's bounds if the element is scrollable.
1733    ///
1734    /// the final computed style will be passed to the provided function, along
1735    /// with the current scroll offset
1736    pub fn paint(
1737        &mut self,
1738        global_id: Option<&GlobalElementId>,
1739        _inspector_id: Option<&InspectorElementId>,
1740        bounds: Bounds<Pixels>,
1741        hitbox: Option<&Hitbox>,
1742        window: &mut Window,
1743        cx: &mut App,
1744        f: impl FnOnce(&Style, &mut Window, &mut App),
1745    ) {
1746        self.hovered = hitbox.map(|hitbox| hitbox.is_hovered(window));
1747        window.with_optional_element_state::<InteractiveElementState, _>(
1748            global_id,
1749            |element_state, window| {
1750                let mut element_state =
1751                    element_state.map(|element_state| element_state.unwrap_or_default());
1752
1753                let style = self.compute_style_internal(hitbox, element_state.as_mut(), window, cx);
1754
1755                #[cfg(any(feature = "test-support", test))]
1756                if let Some(debug_selector) = &self.debug_selector {
1757                    window
1758                        .next_frame
1759                        .debug_bounds
1760                        .insert(debug_selector.clone(), bounds);
1761                }
1762
1763                self.paint_hover_group_handler(window, cx);
1764
1765                if style.visibility == Visibility::Hidden {
1766                    return ((), element_state);
1767                }
1768
1769                if let Some(focus_handle) = &self.tracked_focus_handle {
1770                    window.next_frame.tab_handles.insert(focus_handle);
1771                }
1772
1773                window.with_element_opacity(style.opacity, |window| {
1774                    style.paint(bounds, window, cx, |window: &mut Window, cx: &mut App| {
1775                        window.with_text_style(style.text_style().cloned(), |window| {
1776                            window.with_content_mask(
1777                                style.overflow_mask(bounds, window.rem_size()),
1778                                |window| {
1779                                    if let Some(hitbox) = hitbox {
1780                                        #[cfg(debug_assertions)]
1781                                        self.paint_debug_info(
1782                                            global_id, hitbox, &style, window, cx,
1783                                        );
1784
1785                                        if let Some(drag) = cx.active_drag.as_ref() {
1786                                            if let Some(mouse_cursor) = drag.cursor_style {
1787                                                window.set_window_cursor_style(mouse_cursor);
1788                                            }
1789                                        } else {
1790                                            if let Some(mouse_cursor) = style.mouse_cursor {
1791                                                window.set_cursor_style(mouse_cursor, hitbox);
1792                                            }
1793                                        }
1794
1795                                        if let Some(group) = self.group.clone() {
1796                                            GroupHitboxes::push(group, hitbox.id, cx);
1797                                        }
1798
1799                                        if let Some(area) = self.window_control {
1800                                            window
1801                                                .insert_window_control_hitbox(area, hitbox.clone());
1802                                        }
1803
1804                                        self.paint_mouse_listeners(
1805                                            hitbox,
1806                                            element_state.as_mut(),
1807                                            window,
1808                                            cx,
1809                                        );
1810                                        self.paint_scroll_listener(hitbox, &style, window, cx);
1811                                    }
1812
1813                                    self.paint_keyboard_listeners(window, cx);
1814                                    f(&style, window, cx);
1815
1816                                    if let Some(_hitbox) = hitbox {
1817                                        #[cfg(any(feature = "inspector", debug_assertions))]
1818                                        window.insert_inspector_hitbox(
1819                                            _hitbox.id,
1820                                            _inspector_id,
1821                                            cx,
1822                                        );
1823
1824                                        if let Some(group) = self.group.as_ref() {
1825                                            GroupHitboxes::pop(group, cx);
1826                                        }
1827                                    }
1828                                },
1829                            );
1830                        });
1831                    });
1832                });
1833
1834                ((), element_state)
1835            },
1836        );
1837    }
1838
1839    #[cfg(debug_assertions)]
1840    fn paint_debug_info(
1841        &self,
1842        global_id: Option<&GlobalElementId>,
1843        hitbox: &Hitbox,
1844        style: &Style,
1845        window: &mut Window,
1846        cx: &mut App,
1847    ) {
1848        use crate::{BorderStyle, TextAlign};
1849
1850        if global_id.is_some()
1851            && (style.debug || style.debug_below || cx.has_global::<crate::DebugBelow>())
1852            && hitbox.is_hovered(window)
1853        {
1854            const FONT_SIZE: crate::Pixels = crate::Pixels(10.);
1855            let element_id = format!("{:?}", global_id.unwrap());
1856            let str_len = element_id.len();
1857
1858            let render_debug_text = |window: &mut Window| {
1859                if let Some(text) = window
1860                    .text_system()
1861                    .shape_text(
1862                        element_id.into(),
1863                        FONT_SIZE,
1864                        &[window.text_style().to_run(str_len)],
1865                        None,
1866                        None,
1867                    )
1868                    .ok()
1869                    .and_then(|mut text| text.pop())
1870                {
1871                    text.paint(hitbox.origin, FONT_SIZE, TextAlign::Left, None, window, cx)
1872                        .ok();
1873
1874                    let text_bounds = crate::Bounds {
1875                        origin: hitbox.origin,
1876                        size: text.size(FONT_SIZE),
1877                    };
1878                    if self.source_location.is_some()
1879                        && text_bounds.contains(&window.mouse_position())
1880                        && window.modifiers().secondary()
1881                    {
1882                        let secondary_held = window.modifiers().secondary();
1883                        window.on_key_event({
1884                            move |e: &crate::ModifiersChangedEvent, _phase, window, _cx| {
1885                                if e.modifiers.secondary() != secondary_held
1886                                    && text_bounds.contains(&window.mouse_position())
1887                                {
1888                                    window.refresh();
1889                                }
1890                            }
1891                        });
1892
1893                        let was_hovered = hitbox.is_hovered(window);
1894                        let current_view = window.current_view();
1895                        window.on_mouse_event({
1896                            let hitbox = hitbox.clone();
1897                            move |_: &MouseMoveEvent, phase, window, cx| {
1898                                if phase == DispatchPhase::Capture {
1899                                    let hovered = hitbox.is_hovered(window);
1900                                    if hovered != was_hovered {
1901                                        cx.notify(current_view)
1902                                    }
1903                                }
1904                            }
1905                        });
1906
1907                        window.on_mouse_event({
1908                            let hitbox = hitbox.clone();
1909                            let location = self.source_location.unwrap();
1910                            move |e: &crate::MouseDownEvent, phase, window, cx| {
1911                                if text_bounds.contains(&e.position)
1912                                    && phase.capture()
1913                                    && hitbox.is_hovered(window)
1914                                {
1915                                    cx.stop_propagation();
1916                                    let Ok(dir) = std::env::current_dir() else {
1917                                        return;
1918                                    };
1919
1920                                    eprintln!(
1921                                        "This element was created at:\n{}:{}:{}",
1922                                        dir.join(location.file()).to_string_lossy(),
1923                                        location.line(),
1924                                        location.column()
1925                                    );
1926                                }
1927                            }
1928                        });
1929                        window.paint_quad(crate::outline(
1930                            crate::Bounds {
1931                                origin: hitbox.origin
1932                                    + crate::point(crate::px(0.), FONT_SIZE - px(2.)),
1933                                size: crate::Size {
1934                                    width: text_bounds.size.width,
1935                                    height: crate::px(1.),
1936                                },
1937                            },
1938                            crate::red(),
1939                            BorderStyle::default(),
1940                        ))
1941                    }
1942                }
1943            };
1944
1945            window.with_text_style(
1946                Some(crate::TextStyleRefinement {
1947                    color: Some(crate::red()),
1948                    line_height: Some(FONT_SIZE.into()),
1949                    background_color: Some(crate::white()),
1950                    ..Default::default()
1951                }),
1952                render_debug_text,
1953            )
1954        }
1955    }
1956
1957    fn paint_mouse_listeners(
1958        &mut self,
1959        hitbox: &Hitbox,
1960        element_state: Option<&mut InteractiveElementState>,
1961        window: &mut Window,
1962        cx: &mut App,
1963    ) {
1964        let is_focused = self
1965            .tracked_focus_handle
1966            .as_ref()
1967            .map(|handle| handle.is_focused(window))
1968            .unwrap_or(false);
1969
1970        // If this element can be focused, register a mouse down listener
1971        // that will automatically transfer focus when hitting the element.
1972        // This behavior can be suppressed by using `cx.prevent_default()`.
1973        if let Some(focus_handle) = self.tracked_focus_handle.clone() {
1974            let hitbox = hitbox.clone();
1975            window.on_mouse_event(move |_: &MouseDownEvent, phase, window, _| {
1976                if phase == DispatchPhase::Bubble
1977                    && hitbox.is_hovered(window)
1978                    && !window.default_prevented()
1979                {
1980                    window.focus(&focus_handle);
1981                    // If there is a parent that is also focusable, prevent it
1982                    // from transferring focus because we already did so.
1983                    window.prevent_default();
1984                }
1985            });
1986        }
1987
1988        for listener in self.mouse_down_listeners.drain(..) {
1989            let hitbox = hitbox.clone();
1990            window.on_mouse_event(move |event: &MouseDownEvent, phase, window, cx| {
1991                listener(event, phase, &hitbox, window, cx);
1992            })
1993        }
1994
1995        for listener in self.mouse_up_listeners.drain(..) {
1996            let hitbox = hitbox.clone();
1997            window.on_mouse_event(move |event: &MouseUpEvent, phase, window, cx| {
1998                listener(event, phase, &hitbox, window, cx);
1999            })
2000        }
2001
2002        for listener in self.mouse_move_listeners.drain(..) {
2003            let hitbox = hitbox.clone();
2004            window.on_mouse_event(move |event: &MouseMoveEvent, phase, window, cx| {
2005                listener(event, phase, &hitbox, window, cx);
2006            })
2007        }
2008
2009        for listener in self.scroll_wheel_listeners.drain(..) {
2010            let hitbox = hitbox.clone();
2011            window.on_mouse_event(move |event: &ScrollWheelEvent, phase, window, cx| {
2012                listener(event, phase, &hitbox, window, cx);
2013            })
2014        }
2015
2016        if self.hover_style.is_some()
2017            || self.base_style.mouse_cursor.is_some()
2018            || cx.active_drag.is_some() && !self.drag_over_styles.is_empty()
2019        {
2020            let hitbox = hitbox.clone();
2021            let was_hovered = hitbox.is_hovered(window);
2022            let current_view = window.current_view();
2023            window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2024                let hovered = hitbox.is_hovered(window);
2025                if phase == DispatchPhase::Capture && hovered != was_hovered {
2026                    cx.notify(current_view);
2027                }
2028            });
2029        }
2030        let drag_cursor_style = self.base_style.as_ref().mouse_cursor;
2031
2032        let mut drag_listener = mem::take(&mut self.drag_listener);
2033        let drop_listeners = mem::take(&mut self.drop_listeners);
2034        let click_listeners = mem::take(&mut self.click_listeners);
2035        let can_drop_predicate = mem::take(&mut self.can_drop_predicate);
2036
2037        if !drop_listeners.is_empty() {
2038            let hitbox = hitbox.clone();
2039            window.on_mouse_event({
2040                move |_: &MouseUpEvent, phase, window, cx| {
2041                    if let Some(drag) = &cx.active_drag {
2042                        if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
2043                            let drag_state_type = drag.value.as_ref().type_id();
2044                            for (drop_state_type, listener) in &drop_listeners {
2045                                if *drop_state_type == drag_state_type {
2046                                    let drag = cx
2047                                        .active_drag
2048                                        .take()
2049                                        .expect("checked for type drag state type above");
2050
2051                                    let mut can_drop = true;
2052                                    if let Some(predicate) = &can_drop_predicate {
2053                                        can_drop = predicate(drag.value.as_ref(), window, cx);
2054                                    }
2055
2056                                    if can_drop {
2057                                        listener(drag.value.as_ref(), window, cx);
2058                                        window.refresh();
2059                                        cx.stop_propagation();
2060                                    }
2061                                }
2062                            }
2063                        }
2064                    }
2065                }
2066            });
2067        }
2068
2069        if let Some(element_state) = element_state {
2070            if !click_listeners.is_empty() || drag_listener.is_some() {
2071                let pending_mouse_down = element_state
2072                    .pending_mouse_down
2073                    .get_or_insert_with(Default::default)
2074                    .clone();
2075
2076                let clicked_state = element_state
2077                    .clicked_state
2078                    .get_or_insert_with(Default::default)
2079                    .clone();
2080
2081                window.on_mouse_event({
2082                    let pending_mouse_down = pending_mouse_down.clone();
2083                    let hitbox = hitbox.clone();
2084                    move |event: &MouseDownEvent, phase, window, _cx| {
2085                        if phase == DispatchPhase::Bubble
2086                            && event.button == MouseButton::Left
2087                            && hitbox.is_hovered(window)
2088                        {
2089                            *pending_mouse_down.borrow_mut() = Some(event.clone());
2090                            window.refresh();
2091                        }
2092                    }
2093                });
2094
2095                window.on_mouse_event({
2096                    let pending_mouse_down = pending_mouse_down.clone();
2097                    let hitbox = hitbox.clone();
2098                    move |event: &MouseMoveEvent, phase, window, cx| {
2099                        if phase == DispatchPhase::Capture {
2100                            return;
2101                        }
2102
2103                        let mut pending_mouse_down = pending_mouse_down.borrow_mut();
2104                        if let Some(mouse_down) = pending_mouse_down.clone() {
2105                            if !cx.has_active_drag()
2106                                && (event.position - mouse_down.position).magnitude()
2107                                    > DRAG_THRESHOLD
2108                            {
2109                                if let Some((drag_value, drag_listener)) = drag_listener.take() {
2110                                    *clicked_state.borrow_mut() = ElementClickedState::default();
2111                                    let cursor_offset = event.position - hitbox.origin;
2112                                    let drag = (drag_listener)(
2113                                        drag_value.as_ref(),
2114                                        cursor_offset,
2115                                        window,
2116                                        cx,
2117                                    );
2118                                    cx.active_drag = Some(AnyDrag {
2119                                        view: drag,
2120                                        value: drag_value,
2121                                        cursor_offset,
2122                                        cursor_style: drag_cursor_style,
2123                                    });
2124                                    pending_mouse_down.take();
2125                                    window.refresh();
2126                                    cx.stop_propagation();
2127                                }
2128                            }
2129                        }
2130                    }
2131                });
2132
2133                if is_focused {
2134                    // Press enter, space to trigger click, when the element is focused.
2135                    window.on_key_event({
2136                        let click_listeners = click_listeners.clone();
2137                        let hitbox = hitbox.clone();
2138                        move |event: &KeyUpEvent, phase, window, cx| {
2139                            if phase.bubble() && !window.default_prevented() {
2140                                let stroke = &event.keystroke;
2141                                let keyboard_button = if stroke.key.eq("enter") {
2142                                    Some(KeyboardButton::Enter)
2143                                } else if stroke.key.eq("space") {
2144                                    Some(KeyboardButton::Space)
2145                                } else {
2146                                    None
2147                                };
2148
2149                                if let Some(button) = keyboard_button
2150                                    && !stroke.modifiers.modified()
2151                                {
2152                                    let click_event = ClickEvent::Keyboard(KeyboardClickEvent {
2153                                        button,
2154                                        bounds: hitbox.bounds,
2155                                    });
2156
2157                                    for listener in &click_listeners {
2158                                        listener(&click_event, window, cx);
2159                                    }
2160                                }
2161                            }
2162                        }
2163                    });
2164                }
2165
2166                window.on_mouse_event({
2167                    let mut captured_mouse_down = None;
2168                    let hitbox = hitbox.clone();
2169                    move |event: &MouseUpEvent, phase, window, cx| match phase {
2170                        // Clear the pending mouse down during the capture phase,
2171                        // so that it happens even if another event handler stops
2172                        // propagation.
2173                        DispatchPhase::Capture => {
2174                            let mut pending_mouse_down = pending_mouse_down.borrow_mut();
2175                            if pending_mouse_down.is_some() && hitbox.is_hovered(window) {
2176                                captured_mouse_down = pending_mouse_down.take();
2177                                window.refresh();
2178                            } else if pending_mouse_down.is_some() {
2179                                // Clear the pending mouse down event (without firing click handlers)
2180                                // if the hitbox is not being hovered.
2181                                // This avoids dragging elements that changed their position
2182                                // immediately after being clicked.
2183                                // See https://github.com/zed-industries/zed/issues/24600 for more details
2184                                pending_mouse_down.take();
2185                                window.refresh();
2186                            }
2187                        }
2188                        // Fire click handlers during the bubble phase.
2189                        DispatchPhase::Bubble => {
2190                            if let Some(mouse_down) = captured_mouse_down.take() {
2191                                let mouse_click = ClickEvent::Mouse(MouseClickEvent {
2192                                    down: mouse_down,
2193                                    up: event.clone(),
2194                                });
2195                                for listener in &click_listeners {
2196                                    listener(&mouse_click, window, cx);
2197                                }
2198                            }
2199                        }
2200                    }
2201                });
2202            }
2203
2204            if let Some(hover_listener) = self.hover_listener.take() {
2205                let hitbox = hitbox.clone();
2206                let was_hovered = element_state
2207                    .hover_state
2208                    .get_or_insert_with(Default::default)
2209                    .clone();
2210                let has_mouse_down = element_state
2211                    .pending_mouse_down
2212                    .get_or_insert_with(Default::default)
2213                    .clone();
2214
2215                window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2216                    if phase != DispatchPhase::Bubble {
2217                        return;
2218                    }
2219                    let is_hovered = has_mouse_down.borrow().is_none()
2220                        && !cx.has_active_drag()
2221                        && hitbox.is_hovered(window);
2222                    let mut was_hovered = was_hovered.borrow_mut();
2223
2224                    if is_hovered != *was_hovered {
2225                        *was_hovered = is_hovered;
2226                        drop(was_hovered);
2227
2228                        hover_listener(&is_hovered, window, cx);
2229                    }
2230                });
2231            }
2232
2233            if let Some(tooltip_builder) = self.tooltip_builder.take() {
2234                let active_tooltip = element_state
2235                    .active_tooltip
2236                    .get_or_insert_with(Default::default)
2237                    .clone();
2238                let pending_mouse_down = element_state
2239                    .pending_mouse_down
2240                    .get_or_insert_with(Default::default)
2241                    .clone();
2242
2243                let tooltip_is_hoverable = tooltip_builder.hoverable;
2244                let build_tooltip = Rc::new(move |window: &mut Window, cx: &mut App| {
2245                    Some(((tooltip_builder.build)(window, cx), tooltip_is_hoverable))
2246                });
2247                // Use bounds instead of testing hitbox since this is called during prepaint.
2248                let check_is_hovered_during_prepaint = Rc::new({
2249                    let pending_mouse_down = pending_mouse_down.clone();
2250                    let source_bounds = hitbox.bounds;
2251                    move |window: &Window| {
2252                        pending_mouse_down.borrow().is_none()
2253                            && source_bounds.contains(&window.mouse_position())
2254                    }
2255                });
2256                let check_is_hovered = Rc::new({
2257                    let hitbox = hitbox.clone();
2258                    move |window: &Window| {
2259                        pending_mouse_down.borrow().is_none() && hitbox.is_hovered(window)
2260                    }
2261                });
2262                register_tooltip_mouse_handlers(
2263                    &active_tooltip,
2264                    self.tooltip_id,
2265                    build_tooltip,
2266                    check_is_hovered,
2267                    check_is_hovered_during_prepaint,
2268                    window,
2269                );
2270            }
2271
2272            let active_state = element_state
2273                .clicked_state
2274                .get_or_insert_with(Default::default)
2275                .clone();
2276            if active_state.borrow().is_clicked() {
2277                window.on_mouse_event(move |_: &MouseUpEvent, phase, window, _cx| {
2278                    if phase == DispatchPhase::Capture {
2279                        *active_state.borrow_mut() = ElementClickedState::default();
2280                        window.refresh();
2281                    }
2282                });
2283            } else {
2284                let active_group_hitbox = self
2285                    .group_active_style
2286                    .as_ref()
2287                    .and_then(|group_active| GroupHitboxes::get(&group_active.group, cx));
2288                let hitbox = hitbox.clone();
2289                window.on_mouse_event(move |_: &MouseDownEvent, phase, window, _cx| {
2290                    if phase == DispatchPhase::Bubble && !window.default_prevented() {
2291                        let group_hovered = active_group_hitbox
2292                            .map_or(false, |group_hitbox_id| group_hitbox_id.is_hovered(window));
2293                        let element_hovered = hitbox.is_hovered(window);
2294                        if group_hovered || element_hovered {
2295                            *active_state.borrow_mut() = ElementClickedState {
2296                                group: group_hovered,
2297                                element: element_hovered,
2298                            };
2299                            window.refresh();
2300                        }
2301                    }
2302                });
2303            }
2304        }
2305    }
2306
2307    fn paint_keyboard_listeners(&mut self, window: &mut Window, _cx: &mut App) {
2308        let key_down_listeners = mem::take(&mut self.key_down_listeners);
2309        let key_up_listeners = mem::take(&mut self.key_up_listeners);
2310        let modifiers_changed_listeners = mem::take(&mut self.modifiers_changed_listeners);
2311        let action_listeners = mem::take(&mut self.action_listeners);
2312        if let Some(context) = self.key_context.clone() {
2313            window.set_key_context(context);
2314        }
2315
2316        for listener in key_down_listeners {
2317            window.on_key_event(move |event: &KeyDownEvent, phase, window, cx| {
2318                listener(event, phase, window, cx);
2319            })
2320        }
2321
2322        for listener in key_up_listeners {
2323            window.on_key_event(move |event: &KeyUpEvent, phase, window, cx| {
2324                listener(event, phase, window, cx);
2325            })
2326        }
2327
2328        for listener in modifiers_changed_listeners {
2329            window.on_modifiers_changed(move |event: &ModifiersChangedEvent, window, cx| {
2330                listener(event, window, cx);
2331            })
2332        }
2333
2334        for (action_type, listener) in action_listeners {
2335            window.on_action(action_type, listener)
2336        }
2337    }
2338
2339    fn paint_hover_group_handler(&self, window: &mut Window, cx: &mut App) {
2340        let group_hitbox = self
2341            .group_hover_style
2342            .as_ref()
2343            .and_then(|group_hover| GroupHitboxes::get(&group_hover.group, cx));
2344
2345        if let Some(group_hitbox) = group_hitbox {
2346            let was_hovered = group_hitbox.is_hovered(window);
2347            let current_view = window.current_view();
2348            window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2349                let hovered = group_hitbox.is_hovered(window);
2350                if phase == DispatchPhase::Capture && hovered != was_hovered {
2351                    cx.notify(current_view);
2352                }
2353            });
2354        }
2355    }
2356
2357    fn paint_scroll_listener(
2358        &self,
2359        hitbox: &Hitbox,
2360        style: &Style,
2361        window: &mut Window,
2362        _cx: &mut App,
2363    ) {
2364        if let Some(scroll_offset) = self.scroll_offset.clone() {
2365            let overflow = style.overflow;
2366            let allow_concurrent_scroll = style.allow_concurrent_scroll;
2367            let restrict_scroll_to_axis = style.restrict_scroll_to_axis;
2368            let line_height = window.line_height();
2369            let hitbox = hitbox.clone();
2370            let current_view = window.current_view();
2371            window.on_mouse_event(move |event: &ScrollWheelEvent, phase, window, cx| {
2372                if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
2373                    let mut scroll_offset = scroll_offset.borrow_mut();
2374                    let old_scroll_offset = *scroll_offset;
2375                    let delta = event.delta.pixel_delta(line_height);
2376
2377                    let mut delta_x = Pixels::ZERO;
2378                    if overflow.x == Overflow::Scroll {
2379                        if !delta.x.is_zero() {
2380                            delta_x = delta.x;
2381                        } else if !restrict_scroll_to_axis && overflow.y != Overflow::Scroll {
2382                            delta_x = delta.y;
2383                        }
2384                    }
2385                    let mut delta_y = Pixels::ZERO;
2386                    if overflow.y == Overflow::Scroll {
2387                        if !delta.y.is_zero() {
2388                            delta_y = delta.y;
2389                        } else if !restrict_scroll_to_axis && overflow.x != Overflow::Scroll {
2390                            delta_y = delta.x;
2391                        }
2392                    }
2393                    if !allow_concurrent_scroll && !delta_x.is_zero() && !delta_y.is_zero() {
2394                        if delta_x.abs() > delta_y.abs() {
2395                            delta_y = Pixels::ZERO;
2396                        } else {
2397                            delta_x = Pixels::ZERO;
2398                        }
2399                    }
2400                    scroll_offset.y += delta_y;
2401                    scroll_offset.x += delta_x;
2402                    if *scroll_offset != old_scroll_offset {
2403                        cx.notify(current_view);
2404                    }
2405                }
2406            });
2407        }
2408    }
2409
2410    /// Compute the visual style for this element, based on the current bounds and the element's state.
2411    pub fn compute_style(
2412        &self,
2413        global_id: Option<&GlobalElementId>,
2414        hitbox: Option<&Hitbox>,
2415        window: &mut Window,
2416        cx: &mut App,
2417    ) -> Style {
2418        window.with_optional_element_state(global_id, |element_state, window| {
2419            let mut element_state =
2420                element_state.map(|element_state| element_state.unwrap_or_default());
2421            let style = self.compute_style_internal(hitbox, element_state.as_mut(), window, cx);
2422            (style, element_state)
2423        })
2424    }
2425
2426    /// Called from internal methods that have already called with_element_state.
2427    fn compute_style_internal(
2428        &self,
2429        hitbox: Option<&Hitbox>,
2430        element_state: Option<&mut InteractiveElementState>,
2431        window: &mut Window,
2432        cx: &mut App,
2433    ) -> Style {
2434        let mut style = Style::default();
2435        style.refine(&self.base_style);
2436
2437        if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
2438            if let Some(in_focus_style) = self.in_focus_style.as_ref() {
2439                if focus_handle.within_focused(window, cx) {
2440                    style.refine(in_focus_style);
2441                }
2442            }
2443
2444            if let Some(focus_style) = self.focus_style.as_ref() {
2445                if focus_handle.is_focused(window) {
2446                    style.refine(focus_style);
2447                }
2448            }
2449        }
2450
2451        if let Some(hitbox) = hitbox {
2452            if !cx.has_active_drag() {
2453                if let Some(group_hover) = self.group_hover_style.as_ref() {
2454                    if let Some(group_hitbox_id) = GroupHitboxes::get(&group_hover.group, cx) {
2455                        if group_hitbox_id.is_hovered(window) {
2456                            style.refine(&group_hover.style);
2457                        }
2458                    }
2459                }
2460
2461                if let Some(hover_style) = self.hover_style.as_ref() {
2462                    if hitbox.is_hovered(window) {
2463                        style.refine(hover_style);
2464                    }
2465                }
2466            }
2467
2468            if let Some(drag) = cx.active_drag.take() {
2469                let mut can_drop = true;
2470                if let Some(can_drop_predicate) = &self.can_drop_predicate {
2471                    can_drop = can_drop_predicate(drag.value.as_ref(), window, cx);
2472                }
2473
2474                if can_drop {
2475                    for (state_type, group_drag_style) in &self.group_drag_over_styles {
2476                        if let Some(group_hitbox_id) =
2477                            GroupHitboxes::get(&group_drag_style.group, cx)
2478                        {
2479                            if *state_type == drag.value.as_ref().type_id()
2480                                && group_hitbox_id.is_hovered(window)
2481                            {
2482                                style.refine(&group_drag_style.style);
2483                            }
2484                        }
2485                    }
2486
2487                    for (state_type, build_drag_over_style) in &self.drag_over_styles {
2488                        if *state_type == drag.value.as_ref().type_id() && hitbox.is_hovered(window)
2489                        {
2490                            style.refine(&build_drag_over_style(drag.value.as_ref(), window, cx));
2491                        }
2492                    }
2493                }
2494
2495                style.mouse_cursor = drag.cursor_style;
2496                cx.active_drag = Some(drag);
2497            }
2498        }
2499
2500        if let Some(element_state) = element_state {
2501            let clicked_state = element_state
2502                .clicked_state
2503                .get_or_insert_with(Default::default)
2504                .borrow();
2505            if clicked_state.group {
2506                if let Some(group) = self.group_active_style.as_ref() {
2507                    style.refine(&group.style)
2508                }
2509            }
2510
2511            if let Some(active_style) = self.active_style.as_ref() {
2512                if clicked_state.element {
2513                    style.refine(active_style)
2514                }
2515            }
2516        }
2517
2518        style
2519    }
2520}
2521
2522/// The per-frame state of an interactive element. Used for tracking stateful interactions like clicks
2523/// and scroll offsets.
2524#[derive(Default)]
2525pub struct InteractiveElementState {
2526    pub(crate) focus_handle: Option<FocusHandle>,
2527    pub(crate) clicked_state: Option<Rc<RefCell<ElementClickedState>>>,
2528    pub(crate) hover_state: Option<Rc<RefCell<bool>>>,
2529    pub(crate) pending_mouse_down: Option<Rc<RefCell<Option<MouseDownEvent>>>>,
2530    pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
2531    pub(crate) active_tooltip: Option<Rc<RefCell<Option<ActiveTooltip>>>>,
2532}
2533
2534/// Whether or not the element or a group that contains it is clicked by the mouse.
2535#[derive(Copy, Clone, Default, Eq, PartialEq)]
2536pub struct ElementClickedState {
2537    /// True if this element's group has been clicked, false otherwise
2538    pub group: bool,
2539
2540    /// True if this element has been clicked, false otherwise
2541    pub element: bool,
2542}
2543
2544impl ElementClickedState {
2545    fn is_clicked(&self) -> bool {
2546        self.group || self.element
2547    }
2548}
2549
2550pub(crate) enum ActiveTooltip {
2551    /// Currently delaying before showing the tooltip.
2552    WaitingForShow { _task: Task<()> },
2553    /// Tooltip is visible, element was hovered or for hoverable tooltips, the tooltip was hovered.
2554    Visible {
2555        tooltip: AnyTooltip,
2556        is_hoverable: bool,
2557    },
2558    /// Tooltip is visible and hoverable, but the mouse is no longer hovering. Currently delaying
2559    /// before hiding it.
2560    WaitingForHide {
2561        tooltip: AnyTooltip,
2562        _task: Task<()>,
2563    },
2564}
2565
2566pub(crate) fn clear_active_tooltip(
2567    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2568    window: &mut Window,
2569) {
2570    match active_tooltip.borrow_mut().take() {
2571        None => {}
2572        Some(ActiveTooltip::WaitingForShow { .. }) => {}
2573        Some(ActiveTooltip::Visible { .. }) => window.refresh(),
2574        Some(ActiveTooltip::WaitingForHide { .. }) => window.refresh(),
2575    }
2576}
2577
2578pub(crate) fn clear_active_tooltip_if_not_hoverable(
2579    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2580    window: &mut Window,
2581) {
2582    let should_clear = match active_tooltip.borrow().as_ref() {
2583        None => false,
2584        Some(ActiveTooltip::WaitingForShow { .. }) => false,
2585        Some(ActiveTooltip::Visible { is_hoverable, .. }) => !is_hoverable,
2586        Some(ActiveTooltip::WaitingForHide { .. }) => false,
2587    };
2588    if should_clear {
2589        active_tooltip.borrow_mut().take();
2590        window.refresh();
2591    }
2592}
2593
2594pub(crate) fn set_tooltip_on_window(
2595    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2596    window: &mut Window,
2597) -> Option<TooltipId> {
2598    let tooltip = match active_tooltip.borrow().as_ref() {
2599        None => return None,
2600        Some(ActiveTooltip::WaitingForShow { .. }) => return None,
2601        Some(ActiveTooltip::Visible { tooltip, .. }) => tooltip.clone(),
2602        Some(ActiveTooltip::WaitingForHide { tooltip, .. }) => tooltip.clone(),
2603    };
2604    Some(window.set_tooltip(tooltip))
2605}
2606
2607pub(crate) fn register_tooltip_mouse_handlers(
2608    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2609    tooltip_id: Option<TooltipId>,
2610    build_tooltip: Rc<dyn Fn(&mut Window, &mut App) -> Option<(AnyView, bool)>>,
2611    check_is_hovered: Rc<dyn Fn(&Window) -> bool>,
2612    check_is_hovered_during_prepaint: Rc<dyn Fn(&Window) -> bool>,
2613    window: &mut Window,
2614) {
2615    window.on_mouse_event({
2616        let active_tooltip = active_tooltip.clone();
2617        let build_tooltip = build_tooltip.clone();
2618        let check_is_hovered = check_is_hovered.clone();
2619        move |_: &MouseMoveEvent, phase, window, cx| {
2620            handle_tooltip_mouse_move(
2621                &active_tooltip,
2622                &build_tooltip,
2623                &check_is_hovered,
2624                &check_is_hovered_during_prepaint,
2625                phase,
2626                window,
2627                cx,
2628            )
2629        }
2630    });
2631
2632    window.on_mouse_event({
2633        let active_tooltip = active_tooltip.clone();
2634        move |_: &MouseDownEvent, _phase, window: &mut Window, _cx| {
2635            if !tooltip_id.map_or(false, |tooltip_id| tooltip_id.is_hovered(window)) {
2636                clear_active_tooltip_if_not_hoverable(&active_tooltip, window);
2637            }
2638        }
2639    });
2640
2641    window.on_mouse_event({
2642        let active_tooltip = active_tooltip.clone();
2643        move |_: &ScrollWheelEvent, _phase, window: &mut Window, _cx| {
2644            if !tooltip_id.map_or(false, |tooltip_id| tooltip_id.is_hovered(window)) {
2645                clear_active_tooltip_if_not_hoverable(&active_tooltip, window);
2646            }
2647        }
2648    });
2649}
2650
2651/// Handles displaying tooltips when an element is hovered.
2652///
2653/// The mouse hovering logic also relies on being called from window prepaint in order to handle the
2654/// case where the element the tooltip is on is not rendered - in that case its mouse listeners are
2655/// also not registered. During window prepaint, the hitbox information is not available, so
2656/// `check_is_hovered_during_prepaint` is used which bases the check off of the absolute bounds of
2657/// the element.
2658///
2659/// TODO: There's a minor bug due to the use of absolute bounds while checking during prepaint - it
2660/// does not know if the hitbox is occluded. In the case where a tooltip gets displayed and then
2661/// gets occluded after display, it will stick around until the mouse exits the hover bounds.
2662fn handle_tooltip_mouse_move(
2663    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2664    build_tooltip: &Rc<dyn Fn(&mut Window, &mut App) -> Option<(AnyView, bool)>>,
2665    check_is_hovered: &Rc<dyn Fn(&Window) -> bool>,
2666    check_is_hovered_during_prepaint: &Rc<dyn Fn(&Window) -> bool>,
2667    phase: DispatchPhase,
2668    window: &mut Window,
2669    cx: &mut App,
2670) {
2671    // Separates logic for what mutation should occur from applying it, to avoid overlapping
2672    // RefCell borrows.
2673    enum Action {
2674        None,
2675        CancelShow,
2676        ScheduleShow,
2677    }
2678
2679    let action = match active_tooltip.borrow().as_ref() {
2680        None => {
2681            let is_hovered = check_is_hovered(window);
2682            if is_hovered && phase.bubble() {
2683                Action::ScheduleShow
2684            } else {
2685                Action::None
2686            }
2687        }
2688        Some(ActiveTooltip::WaitingForShow { .. }) => {
2689            let is_hovered = check_is_hovered(window);
2690            if is_hovered {
2691                Action::None
2692            } else {
2693                Action::CancelShow
2694            }
2695        }
2696        // These are handled in check_visible_and_update.
2697        Some(ActiveTooltip::Visible { .. }) | Some(ActiveTooltip::WaitingForHide { .. }) => {
2698            Action::None
2699        }
2700    };
2701
2702    match action {
2703        Action::None => {}
2704        Action::CancelShow => {
2705            // Cancel waiting to show tooltip when it is no longer hovered.
2706            active_tooltip.borrow_mut().take();
2707        }
2708        Action::ScheduleShow => {
2709            let delayed_show_task = window.spawn(cx, {
2710                let active_tooltip = active_tooltip.clone();
2711                let build_tooltip = build_tooltip.clone();
2712                let check_is_hovered_during_prepaint = check_is_hovered_during_prepaint.clone();
2713                async move |cx| {
2714                    cx.background_executor().timer(TOOLTIP_SHOW_DELAY).await;
2715                    cx.update(|window, cx| {
2716                        let new_tooltip =
2717                            build_tooltip(window, cx).map(|(view, tooltip_is_hoverable)| {
2718                                let active_tooltip = active_tooltip.clone();
2719                                ActiveTooltip::Visible {
2720                                    tooltip: AnyTooltip {
2721                                        view,
2722                                        mouse_position: window.mouse_position(),
2723                                        check_visible_and_update: Rc::new(
2724                                            move |tooltip_bounds, window, cx| {
2725                                                handle_tooltip_check_visible_and_update(
2726                                                    &active_tooltip,
2727                                                    tooltip_is_hoverable,
2728                                                    &check_is_hovered_during_prepaint,
2729                                                    tooltip_bounds,
2730                                                    window,
2731                                                    cx,
2732                                                )
2733                                            },
2734                                        ),
2735                                    },
2736                                    is_hoverable: tooltip_is_hoverable,
2737                                }
2738                            });
2739                        *active_tooltip.borrow_mut() = new_tooltip;
2740                        window.refresh();
2741                    })
2742                    .ok();
2743                }
2744            });
2745            active_tooltip
2746                .borrow_mut()
2747                .replace(ActiveTooltip::WaitingForShow {
2748                    _task: delayed_show_task,
2749                });
2750        }
2751    }
2752}
2753
2754/// Returns a callback which will be called by window prepaint to update tooltip visibility. The
2755/// purpose of doing this logic here instead of the mouse move handler is that the mouse move
2756/// handler won't get called when the element is not painted (e.g. via use of `visible_on_hover`).
2757fn handle_tooltip_check_visible_and_update(
2758    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
2759    tooltip_is_hoverable: bool,
2760    check_is_hovered: &Rc<dyn Fn(&Window) -> bool>,
2761    tooltip_bounds: Bounds<Pixels>,
2762    window: &mut Window,
2763    cx: &mut App,
2764) -> bool {
2765    // Separates logic for what mutation should occur from applying it, to avoid overlapping RefCell
2766    // borrows.
2767    enum Action {
2768        None,
2769        Hide,
2770        ScheduleHide(AnyTooltip),
2771        CancelHide(AnyTooltip),
2772    }
2773
2774    let is_hovered = check_is_hovered(window)
2775        || (tooltip_is_hoverable && tooltip_bounds.contains(&window.mouse_position()));
2776    let action = match active_tooltip.borrow().as_ref() {
2777        Some(ActiveTooltip::Visible { tooltip, .. }) => {
2778            if is_hovered {
2779                Action::None
2780            } else {
2781                if tooltip_is_hoverable {
2782                    Action::ScheduleHide(tooltip.clone())
2783                } else {
2784                    Action::Hide
2785                }
2786            }
2787        }
2788        Some(ActiveTooltip::WaitingForHide { tooltip, .. }) => {
2789            if is_hovered {
2790                Action::CancelHide(tooltip.clone())
2791            } else {
2792                Action::None
2793            }
2794        }
2795        None | Some(ActiveTooltip::WaitingForShow { .. }) => Action::None,
2796    };
2797
2798    match action {
2799        Action::None => {}
2800        Action::Hide => clear_active_tooltip(&active_tooltip, window),
2801        Action::ScheduleHide(tooltip) => {
2802            let delayed_hide_task = window.spawn(cx, {
2803                let active_tooltip = active_tooltip.clone();
2804                async move |cx| {
2805                    cx.background_executor()
2806                        .timer(HOVERABLE_TOOLTIP_HIDE_DELAY)
2807                        .await;
2808                    if active_tooltip.borrow_mut().take().is_some() {
2809                        cx.update(|window, _cx| window.refresh()).ok();
2810                    }
2811                }
2812            });
2813            active_tooltip
2814                .borrow_mut()
2815                .replace(ActiveTooltip::WaitingForHide {
2816                    tooltip,
2817                    _task: delayed_hide_task,
2818                });
2819        }
2820        Action::CancelHide(tooltip) => {
2821            // Cancel waiting to hide tooltip when it becomes hovered.
2822            active_tooltip.borrow_mut().replace(ActiveTooltip::Visible {
2823                tooltip,
2824                is_hoverable: true,
2825            });
2826        }
2827    }
2828
2829    active_tooltip.borrow().is_some()
2830}
2831
2832#[derive(Default)]
2833pub(crate) struct GroupHitboxes(HashMap<SharedString, SmallVec<[HitboxId; 1]>>);
2834
2835impl Global for GroupHitboxes {}
2836
2837impl GroupHitboxes {
2838    pub fn get(name: &SharedString, cx: &mut App) -> Option<HitboxId> {
2839        cx.default_global::<Self>()
2840            .0
2841            .get(name)
2842            .and_then(|bounds_stack| bounds_stack.last())
2843            .cloned()
2844    }
2845
2846    pub fn push(name: SharedString, hitbox_id: HitboxId, cx: &mut App) {
2847        cx.default_global::<Self>()
2848            .0
2849            .entry(name)
2850            .or_default()
2851            .push(hitbox_id);
2852    }
2853
2854    pub fn pop(name: &SharedString, cx: &mut App) {
2855        cx.default_global::<Self>().0.get_mut(name).unwrap().pop();
2856    }
2857}
2858
2859/// A wrapper around an element that can store state, produced after assigning an ElementId.
2860pub struct Stateful<E> {
2861    pub(crate) element: E,
2862}
2863
2864impl<E> Styled for Stateful<E>
2865where
2866    E: Styled,
2867{
2868    fn style(&mut self) -> &mut StyleRefinement {
2869        self.element.style()
2870    }
2871}
2872
2873impl<E> StatefulInteractiveElement for Stateful<E>
2874where
2875    E: Element,
2876    Self: InteractiveElement,
2877{
2878}
2879
2880impl<E> InteractiveElement for Stateful<E>
2881where
2882    E: InteractiveElement,
2883{
2884    fn interactivity(&mut self) -> &mut Interactivity {
2885        self.element.interactivity()
2886    }
2887}
2888
2889impl<E> Element for Stateful<E>
2890where
2891    E: Element,
2892{
2893    type RequestLayoutState = E::RequestLayoutState;
2894    type PrepaintState = E::PrepaintState;
2895
2896    fn id(&self) -> Option<ElementId> {
2897        self.element.id()
2898    }
2899
2900    fn source_location(&self) -> Option<&'static core::panic::Location<'static>> {
2901        self.element.source_location()
2902    }
2903
2904    fn request_layout(
2905        &mut self,
2906        id: Option<&GlobalElementId>,
2907        inspector_id: Option<&InspectorElementId>,
2908        window: &mut Window,
2909        cx: &mut App,
2910    ) -> (LayoutId, Self::RequestLayoutState) {
2911        self.element.request_layout(id, inspector_id, window, cx)
2912    }
2913
2914    fn prepaint(
2915        &mut self,
2916        id: Option<&GlobalElementId>,
2917        inspector_id: Option<&InspectorElementId>,
2918        bounds: Bounds<Pixels>,
2919        state: &mut Self::RequestLayoutState,
2920        window: &mut Window,
2921        cx: &mut App,
2922    ) -> E::PrepaintState {
2923        self.element
2924            .prepaint(id, inspector_id, bounds, state, window, cx)
2925    }
2926
2927    fn paint(
2928        &mut self,
2929        id: Option<&GlobalElementId>,
2930        inspector_id: Option<&InspectorElementId>,
2931        bounds: Bounds<Pixels>,
2932        request_layout: &mut Self::RequestLayoutState,
2933        prepaint: &mut Self::PrepaintState,
2934        window: &mut Window,
2935        cx: &mut App,
2936    ) {
2937        self.element.paint(
2938            id,
2939            inspector_id,
2940            bounds,
2941            request_layout,
2942            prepaint,
2943            window,
2944            cx,
2945        );
2946    }
2947}
2948
2949impl<E> IntoElement for Stateful<E>
2950where
2951    E: Element,
2952{
2953    type Element = Self;
2954
2955    fn into_element(self) -> Self::Element {
2956        self
2957    }
2958}
2959
2960impl<E> ParentElement for Stateful<E>
2961where
2962    E: ParentElement,
2963{
2964    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
2965        self.element.extend(elements)
2966    }
2967}
2968
2969/// Represents an element that can be scrolled *to* in its parent element.
2970///
2971/// Contrary to [ScrollHandle::scroll_to_item], an anchored element does not have to be an immediate child of the parent.
2972#[derive(Clone)]
2973pub struct ScrollAnchor {
2974    handle: ScrollHandle,
2975    last_origin: Rc<RefCell<Point<Pixels>>>,
2976}
2977
2978impl ScrollAnchor {
2979    /// Creates a [ScrollAnchor] associated with a given [ScrollHandle].
2980    pub fn for_handle(handle: ScrollHandle) -> Self {
2981        Self {
2982            handle,
2983            last_origin: Default::default(),
2984        }
2985    }
2986    /// Request scroll to this item on the next frame.
2987    pub fn scroll_to(&self, window: &mut Window, _cx: &mut App) {
2988        let this = self.clone();
2989
2990        window.on_next_frame(move |_, _| {
2991            let viewport_bounds = this.handle.bounds();
2992            let self_bounds = *this.last_origin.borrow();
2993            this.handle.set_offset(viewport_bounds.origin - self_bounds);
2994        });
2995    }
2996}
2997
2998#[derive(Default, Debug)]
2999struct ScrollHandleState {
3000    offset: Rc<RefCell<Point<Pixels>>>,
3001    bounds: Bounds<Pixels>,
3002    max_offset: Size<Pixels>,
3003    child_bounds: Vec<Bounds<Pixels>>,
3004    scroll_to_bottom: bool,
3005    overflow: Point<Overflow>,
3006}
3007
3008/// A handle to the scrollable aspects of an element.
3009/// Used for accessing scroll state, like the current scroll offset,
3010/// and for mutating the scroll state, like scrolling to a specific child.
3011#[derive(Clone, Debug)]
3012pub struct ScrollHandle(Rc<RefCell<ScrollHandleState>>);
3013
3014impl Default for ScrollHandle {
3015    fn default() -> Self {
3016        Self::new()
3017    }
3018}
3019
3020impl ScrollHandle {
3021    /// Construct a new scroll handle.
3022    pub fn new() -> Self {
3023        Self(Rc::default())
3024    }
3025
3026    /// Get the current scroll offset.
3027    pub fn offset(&self) -> Point<Pixels> {
3028        *self.0.borrow().offset.borrow()
3029    }
3030
3031    /// Get the maximum scroll offset.
3032    pub fn max_offset(&self) -> Size<Pixels> {
3033        self.0.borrow().max_offset
3034    }
3035
3036    /// Get the top child that's scrolled into view.
3037    pub fn top_item(&self) -> usize {
3038        let state = self.0.borrow();
3039        let top = state.bounds.top() - state.offset.borrow().y;
3040
3041        match state.child_bounds.binary_search_by(|bounds| {
3042            if top < bounds.top() {
3043                Ordering::Greater
3044            } else if top > bounds.bottom() {
3045                Ordering::Less
3046            } else {
3047                Ordering::Equal
3048            }
3049        }) {
3050            Ok(ix) => ix,
3051            Err(ix) => ix.min(state.child_bounds.len().saturating_sub(1)),
3052        }
3053    }
3054
3055    /// Return the bounds into which this child is painted
3056    pub fn bounds(&self) -> Bounds<Pixels> {
3057        self.0.borrow().bounds
3058    }
3059
3060    /// Get the bounds for a specific child.
3061    pub fn bounds_for_item(&self, ix: usize) -> Option<Bounds<Pixels>> {
3062        self.0.borrow().child_bounds.get(ix).cloned()
3063    }
3064
3065    /// scroll_to_item scrolls the minimal amount to ensure that the child is
3066    /// fully visible
3067    pub fn scroll_to_item(&self, ix: usize) {
3068        let state = self.0.borrow();
3069
3070        let Some(bounds) = state.child_bounds.get(ix) else {
3071            return;
3072        };
3073
3074        let mut scroll_offset = state.offset.borrow_mut();
3075
3076        if state.overflow.y == Overflow::Scroll {
3077            if bounds.top() + scroll_offset.y < state.bounds.top() {
3078                scroll_offset.y = state.bounds.top() - bounds.top();
3079            } else if bounds.bottom() + scroll_offset.y > state.bounds.bottom() {
3080                scroll_offset.y = state.bounds.bottom() - bounds.bottom();
3081            }
3082        }
3083
3084        if state.overflow.x == Overflow::Scroll {
3085            if bounds.left() + scroll_offset.x < state.bounds.left() {
3086                scroll_offset.x = state.bounds.left() - bounds.left();
3087            } else if bounds.right() + scroll_offset.x > state.bounds.right() {
3088                scroll_offset.x = state.bounds.right() - bounds.right();
3089            }
3090        }
3091    }
3092
3093    /// Scrolls to the bottom.
3094    pub fn scroll_to_bottom(&self) {
3095        let mut state = self.0.borrow_mut();
3096        state.scroll_to_bottom = true;
3097    }
3098
3099    /// Set the offset explicitly. The offset is the distance from the top left of the
3100    /// parent container to the top left of the first child.
3101    /// As you scroll further down the offset becomes more negative.
3102    pub fn set_offset(&self, mut position: Point<Pixels>) {
3103        let state = self.0.borrow();
3104        *state.offset.borrow_mut() = position;
3105    }
3106
3107    /// Get the logical scroll top, based on a child index and a pixel offset.
3108    pub fn logical_scroll_top(&self) -> (usize, Pixels) {
3109        let ix = self.top_item();
3110        let state = self.0.borrow();
3111
3112        if let Some(child_bounds) = state.child_bounds.get(ix) {
3113            (
3114                ix,
3115                child_bounds.top() + state.offset.borrow().y - state.bounds.top(),
3116            )
3117        } else {
3118            (ix, px(0.))
3119        }
3120    }
3121
3122    /// Get the count of children for scrollable item.
3123    pub fn children_count(&self) -> usize {
3124        self.0.borrow().child_bounds.len()
3125    }
3126}