interactive.rs

   1use crate::{
   2    div, point, px, Action, AnyDrag, AnyView, AppContext, BorrowWindow, Bounds, Component,
   3    DispatchContext, DispatchPhase, Div, Element, ElementId, FocusHandle, KeyMatch, Keystroke,
   4    Modifiers, Overflow, Pixels, Point, Render, SharedString, Size, Style, StyleRefinement, View,
   5    ViewContext,
   6};
   7use collections::HashMap;
   8use derive_more::{Deref, DerefMut};
   9use parking_lot::Mutex;
  10use refineable::Refineable;
  11use smallvec::SmallVec;
  12use std::{
  13    any::{Any, TypeId},
  14    fmt::Debug,
  15    marker::PhantomData,
  16    mem,
  17    ops::Deref,
  18    path::PathBuf,
  19    sync::Arc,
  20};
  21
  22const DRAG_THRESHOLD: f64 = 2.;
  23
  24pub trait StatelessInteractive<V: 'static>: Element<V> {
  25    fn stateless_interaction(&mut self) -> &mut StatelessInteraction<V>;
  26
  27    fn hover(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
  28    where
  29        Self: Sized,
  30    {
  31        self.stateless_interaction().hover_style = f(StyleRefinement::default());
  32        self
  33    }
  34
  35    fn group_hover(
  36        mut self,
  37        group_name: impl Into<SharedString>,
  38        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
  39    ) -> Self
  40    where
  41        Self: Sized,
  42    {
  43        self.stateless_interaction().group_hover_style = Some(GroupStyle {
  44            group: group_name.into(),
  45            style: f(StyleRefinement::default()),
  46        });
  47        self
  48    }
  49
  50    fn on_mouse_down(
  51        mut self,
  52        button: MouseButton,
  53        handler: impl Fn(&mut V, &MouseDownEvent, &mut ViewContext<V>) + 'static,
  54    ) -> Self
  55    where
  56        Self: Sized,
  57    {
  58        self.stateless_interaction()
  59            .mouse_down_listeners
  60            .push(Box::new(move |view, event, bounds, phase, cx| {
  61                if phase == DispatchPhase::Bubble
  62                    && event.button == button
  63                    && bounds.contains_point(&event.position)
  64                {
  65                    handler(view, event, cx)
  66                }
  67            }));
  68        self
  69    }
  70
  71    fn on_mouse_up(
  72        mut self,
  73        button: MouseButton,
  74        handler: impl Fn(&mut V, &MouseUpEvent, &mut ViewContext<V>) + 'static,
  75    ) -> Self
  76    where
  77        Self: Sized,
  78    {
  79        self.stateless_interaction()
  80            .mouse_up_listeners
  81            .push(Box::new(move |view, event, bounds, phase, cx| {
  82                if phase == DispatchPhase::Bubble
  83                    && event.button == button
  84                    && bounds.contains_point(&event.position)
  85                {
  86                    handler(view, event, cx)
  87                }
  88            }));
  89        self
  90    }
  91
  92    fn on_mouse_down_out(
  93        mut self,
  94        button: MouseButton,
  95        handler: impl Fn(&mut V, &MouseDownEvent, &mut ViewContext<V>) + 'static,
  96    ) -> Self
  97    where
  98        Self: Sized,
  99    {
 100        self.stateless_interaction()
 101            .mouse_down_listeners
 102            .push(Box::new(move |view, event, bounds, phase, cx| {
 103                if phase == DispatchPhase::Capture
 104                    && event.button == button
 105                    && !bounds.contains_point(&event.position)
 106                {
 107                    handler(view, event, cx)
 108                }
 109            }));
 110        self
 111    }
 112
 113    fn on_mouse_up_out(
 114        mut self,
 115        button: MouseButton,
 116        handler: impl Fn(&mut V, &MouseUpEvent, &mut ViewContext<V>) + 'static,
 117    ) -> Self
 118    where
 119        Self: Sized,
 120    {
 121        self.stateless_interaction()
 122            .mouse_up_listeners
 123            .push(Box::new(move |view, event, bounds, phase, cx| {
 124                if phase == DispatchPhase::Capture
 125                    && event.button == button
 126                    && !bounds.contains_point(&event.position)
 127                {
 128                    handler(view, event, cx);
 129                }
 130            }));
 131        self
 132    }
 133
 134    fn on_mouse_move(
 135        mut self,
 136        handler: impl Fn(&mut V, &MouseMoveEvent, &mut ViewContext<V>) + 'static,
 137    ) -> Self
 138    where
 139        Self: Sized,
 140    {
 141        self.stateless_interaction()
 142            .mouse_move_listeners
 143            .push(Box::new(move |view, event, bounds, phase, cx| {
 144                if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position) {
 145                    handler(view, event, cx);
 146                }
 147            }));
 148        self
 149    }
 150
 151    fn on_scroll_wheel(
 152        mut self,
 153        handler: impl Fn(&mut V, &ScrollWheelEvent, &mut ViewContext<V>) + 'static,
 154    ) -> Self
 155    where
 156        Self: Sized,
 157    {
 158        self.stateless_interaction()
 159            .scroll_wheel_listeners
 160            .push(Box::new(move |view, event, bounds, phase, cx| {
 161                if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position) {
 162                    handler(view, event, cx);
 163                }
 164            }));
 165        self
 166    }
 167
 168    fn context<C>(mut self, context: C) -> Self
 169    where
 170        Self: Sized,
 171        C: TryInto<DispatchContext>,
 172        C::Error: Debug,
 173    {
 174        self.stateless_interaction().dispatch_context =
 175            context.try_into().expect("invalid dispatch context");
 176        self
 177    }
 178
 179    fn on_action<A: 'static>(
 180        mut self,
 181        listener: impl Fn(&mut V, &A, DispatchPhase, &mut ViewContext<V>) + 'static,
 182    ) -> Self
 183    where
 184        Self: Sized,
 185    {
 186        self.stateless_interaction().key_listeners.push((
 187            TypeId::of::<A>(),
 188            Box::new(move |view, event, _, phase, cx| {
 189                let event = event.downcast_ref().unwrap();
 190                listener(view, event, phase, cx);
 191                None
 192            }),
 193        ));
 194        self
 195    }
 196
 197    fn on_key_down(
 198        mut self,
 199        listener: impl Fn(&mut V, &KeyDownEvent, DispatchPhase, &mut ViewContext<V>) + 'static,
 200    ) -> Self
 201    where
 202        Self: Sized,
 203    {
 204        self.stateless_interaction().key_listeners.push((
 205            TypeId::of::<KeyDownEvent>(),
 206            Box::new(move |view, event, _, phase, cx| {
 207                let event = event.downcast_ref().unwrap();
 208                listener(view, event, phase, cx);
 209                None
 210            }),
 211        ));
 212        self
 213    }
 214
 215    fn on_key_up(
 216        mut self,
 217        listener: impl Fn(&mut V, &KeyUpEvent, DispatchPhase, &mut ViewContext<V>) + 'static,
 218    ) -> Self
 219    where
 220        Self: Sized,
 221    {
 222        self.stateless_interaction().key_listeners.push((
 223            TypeId::of::<KeyUpEvent>(),
 224            Box::new(move |view, event, _, phase, cx| {
 225                let event = event.downcast_ref().unwrap();
 226                listener(view, event, phase, cx);
 227                None
 228            }),
 229        ));
 230        self
 231    }
 232
 233    fn drag_over<S: 'static>(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
 234    where
 235        Self: Sized,
 236    {
 237        self.stateless_interaction()
 238            .drag_over_styles
 239            .push((TypeId::of::<S>(), f(StyleRefinement::default())));
 240        self
 241    }
 242
 243    fn group_drag_over<S: 'static>(
 244        mut self,
 245        group_name: impl Into<SharedString>,
 246        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
 247    ) -> Self
 248    where
 249        Self: Sized,
 250    {
 251        self.stateless_interaction().group_drag_over_styles.push((
 252            TypeId::of::<S>(),
 253            GroupStyle {
 254                group: group_name.into(),
 255                style: f(StyleRefinement::default()),
 256            },
 257        ));
 258        self
 259    }
 260
 261    fn on_drop<W: 'static>(
 262        mut self,
 263        listener: impl Fn(&mut V, View<W>, &mut ViewContext<V>) + 'static,
 264    ) -> Self
 265    where
 266        Self: Sized,
 267    {
 268        self.stateless_interaction().drop_listeners.push((
 269            TypeId::of::<W>(),
 270            Box::new(move |view, dragged_view, cx| {
 271                listener(view, dragged_view.downcast().unwrap(), cx);
 272            }),
 273        ));
 274        self
 275    }
 276}
 277
 278pub trait StatefulInteractive<V: 'static>: StatelessInteractive<V> {
 279    fn stateful_interaction(&mut self) -> &mut StatefulInteraction<V>;
 280
 281    fn active(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
 282    where
 283        Self: Sized,
 284    {
 285        self.stateful_interaction().active_style = f(StyleRefinement::default());
 286        self
 287    }
 288
 289    fn group_active(
 290        mut self,
 291        group_name: impl Into<SharedString>,
 292        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
 293    ) -> Self
 294    where
 295        Self: Sized,
 296    {
 297        self.stateful_interaction().group_active_style = Some(GroupStyle {
 298            group: group_name.into(),
 299            style: f(StyleRefinement::default()),
 300        });
 301        self
 302    }
 303
 304    fn on_click(
 305        mut self,
 306        listener: impl Fn(&mut V, &ClickEvent, &mut ViewContext<V>) + 'static,
 307    ) -> Self
 308    where
 309        Self: Sized,
 310    {
 311        self.stateful_interaction()
 312            .click_listeners
 313            .push(Box::new(move |view, event, cx| listener(view, event, cx)));
 314        self
 315    }
 316
 317    fn on_drag<W>(
 318        mut self,
 319        listener: impl Fn(&mut V, &mut ViewContext<V>) -> View<W> + 'static,
 320    ) -> Self
 321    where
 322        Self: Sized,
 323        W: 'static + Render,
 324    {
 325        debug_assert!(
 326            self.stateful_interaction().drag_listener.is_none(),
 327            "calling on_drag more than once on the same element is not supported"
 328        );
 329        self.stateful_interaction().drag_listener =
 330            Some(Box::new(move |view_state, cursor_offset, cx| AnyDrag {
 331                view: listener(view_state, cx).into(),
 332                cursor_offset,
 333            }));
 334        self
 335    }
 336
 337    fn on_hover(mut self, listener: impl 'static + Fn(&mut V, bool, &mut ViewContext<V>)) -> Self
 338    where
 339        Self: Sized,
 340    {
 341        debug_assert!(
 342            self.stateful_interaction().hover_listener.is_none(),
 343            "calling on_hover more than once on the same element is not supported"
 344        );
 345        self.stateful_interaction().hover_listener = Some(Box::new(listener));
 346        self
 347    }
 348
 349    fn tooltip<W>(
 350        mut self,
 351        build_tooltip: impl Fn(&mut V, &mut ViewContext<V>) -> View<W> + 'static,
 352    ) -> Self
 353    where
 354        Self: Sized,
 355        W: 'static + Render,
 356    {
 357        debug_assert!(
 358            self.stateful_interaction().tooltip_builder.is_none(),
 359            "calling tooltip more than once on the same element is not supported"
 360        );
 361        self.stateful_interaction().tooltip_builder = Some(Box::new(move |view_state, cx| {
 362            build_tooltip(view_state, cx).into()
 363        }));
 364
 365        self
 366    }
 367}
 368
 369pub trait ElementInteraction<V: 'static>: 'static {
 370    fn as_stateless(&self) -> &StatelessInteraction<V>;
 371    fn as_stateless_mut(&mut self) -> &mut StatelessInteraction<V>;
 372    fn as_stateful(&self) -> Option<&StatefulInteraction<V>>;
 373    fn as_stateful_mut(&mut self) -> Option<&mut StatefulInteraction<V>>;
 374
 375    fn initialize<R>(
 376        &mut self,
 377        cx: &mut ViewContext<V>,
 378        f: impl FnOnce(&mut ViewContext<V>) -> R,
 379    ) -> R {
 380        if let Some(stateful) = self.as_stateful_mut() {
 381            cx.with_element_id(stateful.id.clone(), |global_id, cx| {
 382                stateful.key_listeners.push((
 383                    TypeId::of::<KeyDownEvent>(),
 384                    Box::new(move |_, key_down, context, phase, cx| {
 385                        if phase == DispatchPhase::Bubble {
 386                            let key_down = key_down.downcast_ref::<KeyDownEvent>().unwrap();
 387                            if let KeyMatch::Some(action) =
 388                                cx.match_keystroke(&global_id, &key_down.keystroke, context)
 389                            {
 390                                return Some(action);
 391                            }
 392                        }
 393
 394                        None
 395                    }),
 396                ));
 397                let result = stateful.stateless.initialize(cx, f);
 398                stateful.key_listeners.pop();
 399                result
 400            })
 401        } else {
 402            let stateless = self.as_stateless_mut();
 403            cx.with_key_dispatch_context(stateless.dispatch_context.clone(), |cx| {
 404                cx.with_key_listeners(mem::take(&mut stateless.key_listeners), f)
 405            })
 406        }
 407    }
 408
 409    fn refine_style(
 410        &self,
 411        style: &mut Style,
 412        bounds: Bounds<Pixels>,
 413        element_state: &InteractiveElementState,
 414        cx: &mut ViewContext<V>,
 415    ) {
 416        let mouse_position = cx.mouse_position();
 417        let stateless = self.as_stateless();
 418        if let Some(group_hover) = stateless.group_hover_style.as_ref() {
 419            if let Some(group_bounds) = GroupBounds::get(&group_hover.group, cx) {
 420                if group_bounds.contains_point(&mouse_position) {
 421                    style.refine(&group_hover.style);
 422                }
 423            }
 424        }
 425        if bounds.contains_point(&mouse_position) {
 426            style.refine(&stateless.hover_style);
 427        }
 428
 429        if let Some(drag) = cx.active_drag.take() {
 430            for (state_type, group_drag_style) in &self.as_stateless().group_drag_over_styles {
 431                if let Some(group_bounds) = GroupBounds::get(&group_drag_style.group, cx) {
 432                    if *state_type == drag.view.entity_type()
 433                        && group_bounds.contains_point(&mouse_position)
 434                    {
 435                        style.refine(&group_drag_style.style);
 436                    }
 437                }
 438            }
 439
 440            for (state_type, drag_over_style) in &self.as_stateless().drag_over_styles {
 441                if *state_type == drag.view.entity_type() && bounds.contains_point(&mouse_position)
 442                {
 443                    style.refine(drag_over_style);
 444                }
 445            }
 446
 447            cx.active_drag = Some(drag);
 448        }
 449
 450        if let Some(stateful) = self.as_stateful() {
 451            let active_state = element_state.active_state.lock();
 452            if active_state.group {
 453                if let Some(group_style) = stateful.group_active_style.as_ref() {
 454                    style.refine(&group_style.style);
 455                }
 456            }
 457            if active_state.element {
 458                style.refine(&stateful.active_style);
 459            }
 460        }
 461    }
 462
 463    fn paint(
 464        &mut self,
 465        bounds: Bounds<Pixels>,
 466        content_size: Size<Pixels>,
 467        overflow: Point<Overflow>,
 468        element_state: &mut InteractiveElementState,
 469        cx: &mut ViewContext<V>,
 470    ) {
 471        let stateless = self.as_stateless_mut();
 472        for listener in stateless.mouse_down_listeners.drain(..) {
 473            cx.on_mouse_event(move |state, event: &MouseDownEvent, phase, cx| {
 474                listener(state, event, &bounds, phase, cx);
 475            })
 476        }
 477
 478        for listener in stateless.mouse_up_listeners.drain(..) {
 479            cx.on_mouse_event(move |state, event: &MouseUpEvent, phase, cx| {
 480                listener(state, event, &bounds, phase, cx);
 481            })
 482        }
 483
 484        for listener in stateless.mouse_move_listeners.drain(..) {
 485            cx.on_mouse_event(move |state, event: &MouseMoveEvent, phase, cx| {
 486                listener(state, event, &bounds, phase, cx);
 487            })
 488        }
 489
 490        for listener in stateless.scroll_wheel_listeners.drain(..) {
 491            cx.on_mouse_event(move |state, event: &ScrollWheelEvent, phase, cx| {
 492                listener(state, event, &bounds, phase, cx);
 493            })
 494        }
 495
 496        let hover_group_bounds = stateless
 497            .group_hover_style
 498            .as_ref()
 499            .and_then(|group_hover| GroupBounds::get(&group_hover.group, cx));
 500
 501        if let Some(group_bounds) = hover_group_bounds {
 502            let hovered = group_bounds.contains_point(&cx.mouse_position());
 503            cx.on_mouse_event(move |_, event: &MouseMoveEvent, phase, cx| {
 504                if phase == DispatchPhase::Capture {
 505                    if group_bounds.contains_point(&event.position) != hovered {
 506                        cx.notify();
 507                    }
 508                }
 509            });
 510        }
 511
 512        if stateless.hover_style.is_some()
 513            || (cx.active_drag.is_some() && !stateless.drag_over_styles.is_empty())
 514        {
 515            let hovered = bounds.contains_point(&cx.mouse_position());
 516            cx.on_mouse_event(move |_, event: &MouseMoveEvent, phase, cx| {
 517                if phase == DispatchPhase::Capture {
 518                    if bounds.contains_point(&event.position) != hovered {
 519                        cx.notify();
 520                    }
 521                }
 522            });
 523        }
 524
 525        if cx.active_drag.is_some() {
 526            let drop_listeners = mem::take(&mut stateless.drop_listeners);
 527            cx.on_mouse_event(move |view, event: &MouseUpEvent, phase, cx| {
 528                if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position) {
 529                    if let Some(drag_state_type) =
 530                        cx.active_drag.as_ref().map(|drag| drag.view.entity_type())
 531                    {
 532                        for (drop_state_type, listener) in &drop_listeners {
 533                            if *drop_state_type == drag_state_type {
 534                                let drag = cx
 535                                    .active_drag
 536                                    .take()
 537                                    .expect("checked for type drag state type above");
 538                                listener(view, drag.view.clone(), cx);
 539                                cx.notify();
 540                                cx.stop_propagation();
 541                            }
 542                        }
 543                    }
 544                }
 545            });
 546        }
 547
 548        if let Some(stateful) = self.as_stateful_mut() {
 549            let click_listeners = mem::take(&mut stateful.click_listeners);
 550            let drag_listener = mem::take(&mut stateful.drag_listener);
 551
 552            if !click_listeners.is_empty() || drag_listener.is_some() {
 553                let pending_mouse_down = element_state.pending_mouse_down.clone();
 554                let mouse_down = pending_mouse_down.lock().clone();
 555                if let Some(mouse_down) = mouse_down {
 556                    if let Some(drag_listener) = drag_listener {
 557                        let active_state = element_state.active_state.clone();
 558
 559                        cx.on_mouse_event(move |view_state, event: &MouseMoveEvent, phase, cx| {
 560                            if cx.active_drag.is_some() {
 561                                if phase == DispatchPhase::Capture {
 562                                    cx.notify();
 563                                }
 564                            } else if phase == DispatchPhase::Bubble
 565                                && bounds.contains_point(&event.position)
 566                                && (event.position - mouse_down.position).magnitude()
 567                                    > DRAG_THRESHOLD
 568                            {
 569                                *active_state.lock() = ActiveState::default();
 570                                let cursor_offset = event.position - bounds.origin;
 571                                let drag = drag_listener(view_state, cursor_offset, cx);
 572                                cx.active_drag = Some(drag);
 573                                cx.notify();
 574                                cx.stop_propagation();
 575                            }
 576                        });
 577                    }
 578
 579                    cx.on_mouse_event(move |view_state, event: &MouseUpEvent, phase, cx| {
 580                        if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position)
 581                        {
 582                            let mouse_click = ClickEvent {
 583                                down: mouse_down.clone(),
 584                                up: event.clone(),
 585                            };
 586                            for listener in &click_listeners {
 587                                listener(view_state, &mouse_click, cx);
 588                            }
 589                        }
 590                        *pending_mouse_down.lock() = None;
 591                    });
 592                } else {
 593                    cx.on_mouse_event(move |_state, event: &MouseDownEvent, phase, _cx| {
 594                        if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position)
 595                        {
 596                            *pending_mouse_down.lock() = Some(event.clone());
 597                        }
 598                    });
 599                }
 600            }
 601
 602            if let Some(hover_listener) = stateful.hover_listener.take() {
 603                let was_hovered = element_state.hover_state.clone();
 604                let has_mouse_down = element_state.pending_mouse_down.lock().is_some();
 605                cx.on_mouse_event(move |view_state, event: &MouseMoveEvent, phase, cx| {
 606                    if phase != DispatchPhase::Bubble {
 607                        return;
 608                    }
 609                    let is_hovered = bounds.contains_point(&event.position) && !has_mouse_down;
 610                    let mut was_hovered = was_hovered.lock();
 611
 612                    if is_hovered != was_hovered.clone() {
 613                        *was_hovered = is_hovered;
 614                        drop(was_hovered);
 615                        hover_listener(view_state, is_hovered, cx);
 616                    }
 617                });
 618            }
 619
 620            let active_state = element_state.active_state.clone();
 621            if active_state.lock().is_none() {
 622                let active_group_bounds = stateful
 623                    .group_active_style
 624                    .as_ref()
 625                    .and_then(|group_active| GroupBounds::get(&group_active.group, cx));
 626                cx.on_mouse_event(move |_view, down: &MouseDownEvent, phase, cx| {
 627                    if phase == DispatchPhase::Bubble {
 628                        let group = active_group_bounds
 629                            .map_or(false, |bounds| bounds.contains_point(&down.position));
 630                        let element = bounds.contains_point(&down.position);
 631                        if group || element {
 632                            *active_state.lock() = ActiveState { group, element };
 633                            cx.notify();
 634                        }
 635                    }
 636                });
 637            } else {
 638                cx.on_mouse_event(move |_, _: &MouseUpEvent, phase, cx| {
 639                    if phase == DispatchPhase::Capture {
 640                        *active_state.lock() = ActiveState::default();
 641                        cx.notify();
 642                    }
 643                });
 644            }
 645
 646            if overflow.x == Overflow::Scroll || overflow.y == Overflow::Scroll {
 647                let scroll_offset = element_state
 648                    .scroll_offset
 649                    .get_or_insert_with(Arc::default)
 650                    .clone();
 651                let line_height = cx.line_height();
 652                let scroll_max = (content_size - bounds.size).max(&Size::default());
 653
 654                cx.on_mouse_event(move |_, event: &ScrollWheelEvent, phase, cx| {
 655                    if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position) {
 656                        let mut scroll_offset = scroll_offset.lock();
 657                        let old_scroll_offset = *scroll_offset;
 658                        let delta = event.delta.pixel_delta(line_height);
 659
 660                        if overflow.x == Overflow::Scroll {
 661                            scroll_offset.x =
 662                                (scroll_offset.x + delta.x).clamp(-scroll_max.width, px(0.));
 663                        }
 664
 665                        if overflow.y == Overflow::Scroll {
 666                            scroll_offset.y =
 667                                (scroll_offset.y + delta.y).clamp(-scroll_max.height, px(0.));
 668                        }
 669
 670                        if *scroll_offset != old_scroll_offset {
 671                            cx.notify();
 672                            cx.stop_propagation();
 673                        }
 674                    }
 675                });
 676            }
 677        }
 678    }
 679}
 680
 681#[derive(Deref, DerefMut)]
 682pub struct StatefulInteraction<V> {
 683    pub id: ElementId,
 684    #[deref]
 685    #[deref_mut]
 686    stateless: StatelessInteraction<V>,
 687    click_listeners: SmallVec<[ClickListener<V>; 2]>,
 688    active_style: StyleRefinement,
 689    group_active_style: Option<GroupStyle>,
 690    drag_listener: Option<DragListener<V>>,
 691    hover_listener: Option<HoverListener<V>>,
 692    tooltip_builder: Option<TooltipBuilder<V>>,
 693}
 694
 695impl<V: 'static> ElementInteraction<V> for StatefulInteraction<V> {
 696    fn as_stateful(&self) -> Option<&StatefulInteraction<V>> {
 697        Some(self)
 698    }
 699
 700    fn as_stateful_mut(&mut self) -> Option<&mut StatefulInteraction<V>> {
 701        Some(self)
 702    }
 703
 704    fn as_stateless(&self) -> &StatelessInteraction<V> {
 705        &self.stateless
 706    }
 707
 708    fn as_stateless_mut(&mut self) -> &mut StatelessInteraction<V> {
 709        &mut self.stateless
 710    }
 711}
 712
 713impl<V> From<ElementId> for StatefulInteraction<V> {
 714    fn from(id: ElementId) -> Self {
 715        Self {
 716            id,
 717            stateless: StatelessInteraction::default(),
 718            click_listeners: SmallVec::new(),
 719            drag_listener: None,
 720            hover_listener: None,
 721            tooltip_builder: None,
 722            active_style: StyleRefinement::default(),
 723            group_active_style: None,
 724        }
 725    }
 726}
 727
 728type DropListener<V> = dyn Fn(&mut V, AnyView, &mut ViewContext<V>) + 'static;
 729
 730pub struct StatelessInteraction<V> {
 731    pub dispatch_context: DispatchContext,
 732    pub mouse_down_listeners: SmallVec<[MouseDownListener<V>; 2]>,
 733    pub mouse_up_listeners: SmallVec<[MouseUpListener<V>; 2]>,
 734    pub mouse_move_listeners: SmallVec<[MouseMoveListener<V>; 2]>,
 735    pub scroll_wheel_listeners: SmallVec<[ScrollWheelListener<V>; 2]>,
 736    pub key_listeners: SmallVec<[(TypeId, KeyListener<V>); 32]>,
 737    pub hover_style: StyleRefinement,
 738    pub group_hover_style: Option<GroupStyle>,
 739    drag_over_styles: SmallVec<[(TypeId, StyleRefinement); 2]>,
 740    group_drag_over_styles: SmallVec<[(TypeId, GroupStyle); 2]>,
 741    drop_listeners: SmallVec<[(TypeId, Box<DropListener<V>>); 2]>,
 742}
 743
 744impl<V> StatelessInteraction<V> {
 745    pub fn into_stateful(self, id: impl Into<ElementId>) -> StatefulInteraction<V> {
 746        StatefulInteraction {
 747            id: id.into(),
 748            stateless: self,
 749            click_listeners: SmallVec::new(),
 750            drag_listener: None,
 751            hover_listener: None,
 752            tooltip_builder: None,
 753            active_style: StyleRefinement::default(),
 754            group_active_style: None,
 755        }
 756    }
 757}
 758
 759pub struct GroupStyle {
 760    pub group: SharedString,
 761    pub style: StyleRefinement,
 762}
 763
 764#[derive(Default)]
 765pub struct GroupBounds(HashMap<SharedString, SmallVec<[Bounds<Pixels>; 1]>>);
 766
 767impl GroupBounds {
 768    pub fn get(name: &SharedString, cx: &mut AppContext) -> Option<Bounds<Pixels>> {
 769        cx.default_global::<Self>()
 770            .0
 771            .get(name)
 772            .and_then(|bounds_stack| bounds_stack.last())
 773            .cloned()
 774    }
 775
 776    pub fn push(name: SharedString, bounds: Bounds<Pixels>, cx: &mut AppContext) {
 777        cx.default_global::<Self>()
 778            .0
 779            .entry(name)
 780            .or_default()
 781            .push(bounds);
 782    }
 783
 784    pub fn pop(name: &SharedString, cx: &mut AppContext) {
 785        cx.default_global::<Self>().0.get_mut(name).unwrap().pop();
 786    }
 787}
 788
 789#[derive(Copy, Clone, Default, Eq, PartialEq)]
 790struct ActiveState {
 791    pub group: bool,
 792    pub element: bool,
 793}
 794
 795impl ActiveState {
 796    pub fn is_none(&self) -> bool {
 797        !self.group && !self.element
 798    }
 799}
 800
 801#[derive(Default)]
 802pub struct InteractiveElementState {
 803    active_state: Arc<Mutex<ActiveState>>,
 804    hover_state: Arc<Mutex<bool>>,
 805    pending_mouse_down: Arc<Mutex<Option<MouseDownEvent>>>,
 806    scroll_offset: Option<Arc<Mutex<Point<Pixels>>>>,
 807}
 808
 809impl InteractiveElementState {
 810    pub fn scroll_offset(&self) -> Option<Point<Pixels>> {
 811        self.scroll_offset
 812            .as_ref()
 813            .map(|offset| offset.lock().clone())
 814    }
 815}
 816
 817impl<V> Default for StatelessInteraction<V> {
 818    fn default() -> Self {
 819        Self {
 820            dispatch_context: DispatchContext::default(),
 821            mouse_down_listeners: SmallVec::new(),
 822            mouse_up_listeners: SmallVec::new(),
 823            mouse_move_listeners: SmallVec::new(),
 824            scroll_wheel_listeners: SmallVec::new(),
 825            key_listeners: SmallVec::new(),
 826            hover_style: StyleRefinement::default(),
 827            group_hover_style: None,
 828            drag_over_styles: SmallVec::new(),
 829            group_drag_over_styles: SmallVec::new(),
 830            drop_listeners: SmallVec::new(),
 831        }
 832    }
 833}
 834
 835impl<V: 'static> ElementInteraction<V> for StatelessInteraction<V> {
 836    fn as_stateful(&self) -> Option<&StatefulInteraction<V>> {
 837        None
 838    }
 839
 840    fn as_stateful_mut(&mut self) -> Option<&mut StatefulInteraction<V>> {
 841        None
 842    }
 843
 844    fn as_stateless(&self) -> &StatelessInteraction<V> {
 845        self
 846    }
 847
 848    fn as_stateless_mut(&mut self) -> &mut StatelessInteraction<V> {
 849        self
 850    }
 851}
 852
 853#[derive(Clone, Debug, Eq, PartialEq)]
 854pub struct KeyDownEvent {
 855    pub keystroke: Keystroke,
 856    pub is_held: bool,
 857}
 858
 859#[derive(Clone, Debug)]
 860pub struct KeyUpEvent {
 861    pub keystroke: Keystroke,
 862}
 863
 864#[derive(Clone, Debug, Default)]
 865pub struct ModifiersChangedEvent {
 866    pub modifiers: Modifiers,
 867}
 868
 869impl Deref for ModifiersChangedEvent {
 870    type Target = Modifiers;
 871
 872    fn deref(&self) -> &Self::Target {
 873        &self.modifiers
 874    }
 875}
 876
 877/// The phase of a touch motion event.
 878/// Based on the winit enum of the same name.
 879#[derive(Clone, Copy, Debug)]
 880pub enum TouchPhase {
 881    Started,
 882    Moved,
 883    Ended,
 884}
 885
 886#[derive(Clone, Debug, Default)]
 887pub struct MouseDownEvent {
 888    pub button: MouseButton,
 889    pub position: Point<Pixels>,
 890    pub modifiers: Modifiers,
 891    pub click_count: usize,
 892}
 893
 894#[derive(Clone, Debug, Default)]
 895pub struct MouseUpEvent {
 896    pub button: MouseButton,
 897    pub position: Point<Pixels>,
 898    pub modifiers: Modifiers,
 899    pub click_count: usize,
 900}
 901
 902#[derive(Clone, Debug, Default)]
 903pub struct ClickEvent {
 904    pub down: MouseDownEvent,
 905    pub up: MouseUpEvent,
 906}
 907
 908pub struct Drag<S, R, V, E>
 909where
 910    R: Fn(&mut V, &mut ViewContext<V>) -> E,
 911    V: 'static,
 912    E: Component<()>,
 913{
 914    pub state: S,
 915    pub render_drag_handle: R,
 916    view_type: PhantomData<V>,
 917}
 918
 919impl<S, R, V, E> Drag<S, R, V, E>
 920where
 921    R: Fn(&mut V, &mut ViewContext<V>) -> E,
 922    V: 'static,
 923    E: Component<()>,
 924{
 925    pub fn new(state: S, render_drag_handle: R) -> Self {
 926        Drag {
 927            state,
 928            render_drag_handle,
 929            view_type: PhantomData,
 930        }
 931    }
 932}
 933
 934// impl<S, R, V, E> Render for Drag<S, R, V, E> {
 935//     // fn render(&mut self, cx: ViewContext<Self>) ->
 936// }
 937
 938#[derive(Hash, PartialEq, Eq, Copy, Clone, Debug)]
 939pub enum MouseButton {
 940    Left,
 941    Right,
 942    Middle,
 943    Navigate(NavigationDirection),
 944}
 945
 946impl MouseButton {
 947    pub fn all() -> Vec<Self> {
 948        vec![
 949            MouseButton::Left,
 950            MouseButton::Right,
 951            MouseButton::Middle,
 952            MouseButton::Navigate(NavigationDirection::Back),
 953            MouseButton::Navigate(NavigationDirection::Forward),
 954        ]
 955    }
 956}
 957
 958impl Default for MouseButton {
 959    fn default() -> Self {
 960        Self::Left
 961    }
 962}
 963
 964#[derive(Hash, PartialEq, Eq, Copy, Clone, Debug)]
 965pub enum NavigationDirection {
 966    Back,
 967    Forward,
 968}
 969
 970impl Default for NavigationDirection {
 971    fn default() -> Self {
 972        Self::Back
 973    }
 974}
 975
 976#[derive(Clone, Debug, Default)]
 977pub struct MouseMoveEvent {
 978    pub position: Point<Pixels>,
 979    pub pressed_button: Option<MouseButton>,
 980    pub modifiers: Modifiers,
 981}
 982
 983#[derive(Clone, Debug)]
 984pub struct ScrollWheelEvent {
 985    pub position: Point<Pixels>,
 986    pub delta: ScrollDelta,
 987    pub modifiers: Modifiers,
 988    pub touch_phase: TouchPhase,
 989}
 990
 991impl Deref for ScrollWheelEvent {
 992    type Target = Modifiers;
 993
 994    fn deref(&self) -> &Self::Target {
 995        &self.modifiers
 996    }
 997}
 998
 999#[derive(Clone, Copy, Debug)]
1000pub enum ScrollDelta {
1001    Pixels(Point<Pixels>),
1002    Lines(Point<f32>),
1003}
1004
1005impl Default for ScrollDelta {
1006    fn default() -> Self {
1007        Self::Lines(Default::default())
1008    }
1009}
1010
1011impl ScrollDelta {
1012    pub fn precise(&self) -> bool {
1013        match self {
1014            ScrollDelta::Pixels(_) => true,
1015            ScrollDelta::Lines(_) => false,
1016        }
1017    }
1018
1019    pub fn pixel_delta(&self, line_height: Pixels) -> Point<Pixels> {
1020        match self {
1021            ScrollDelta::Pixels(delta) => *delta,
1022            ScrollDelta::Lines(delta) => point(line_height * delta.x, line_height * delta.y),
1023        }
1024    }
1025}
1026
1027#[derive(Clone, Debug, Default)]
1028pub struct MouseExitEvent {
1029    pub position: Point<Pixels>,
1030    pub pressed_button: Option<MouseButton>,
1031    pub modifiers: Modifiers,
1032}
1033
1034impl Deref for MouseExitEvent {
1035    type Target = Modifiers;
1036
1037    fn deref(&self) -> &Self::Target {
1038        &self.modifiers
1039    }
1040}
1041
1042#[derive(Debug, Clone, Default)]
1043pub struct ExternalPaths(pub(crate) SmallVec<[PathBuf; 2]>);
1044
1045impl Render for ExternalPaths {
1046    type Element = Div<Self>;
1047
1048    fn render(&mut self, _: &mut ViewContext<Self>) -> Self::Element {
1049        div() // Intentionally left empty because the platform will render icons for the dragged files
1050    }
1051}
1052
1053#[derive(Debug, Clone)]
1054pub enum FileDropEvent {
1055    Entered {
1056        position: Point<Pixels>,
1057        files: ExternalPaths,
1058    },
1059    Pending {
1060        position: Point<Pixels>,
1061    },
1062    Submit {
1063        position: Point<Pixels>,
1064    },
1065    Exited,
1066}
1067
1068#[derive(Clone, Debug)]
1069pub enum InputEvent {
1070    KeyDown(KeyDownEvent),
1071    KeyUp(KeyUpEvent),
1072    ModifiersChanged(ModifiersChangedEvent),
1073    MouseDown(MouseDownEvent),
1074    MouseUp(MouseUpEvent),
1075    MouseMove(MouseMoveEvent),
1076    MouseExited(MouseExitEvent),
1077    ScrollWheel(ScrollWheelEvent),
1078    FileDrop(FileDropEvent),
1079}
1080
1081impl InputEvent {
1082    pub fn position(&self) -> Option<Point<Pixels>> {
1083        match self {
1084            InputEvent::KeyDown { .. } => None,
1085            InputEvent::KeyUp { .. } => None,
1086            InputEvent::ModifiersChanged { .. } => None,
1087            InputEvent::MouseDown(event) => Some(event.position),
1088            InputEvent::MouseUp(event) => Some(event.position),
1089            InputEvent::MouseMove(event) => Some(event.position),
1090            InputEvent::MouseExited(event) => Some(event.position),
1091            InputEvent::ScrollWheel(event) => Some(event.position),
1092            InputEvent::FileDrop(FileDropEvent::Exited) => None,
1093            InputEvent::FileDrop(
1094                FileDropEvent::Entered { position, .. }
1095                | FileDropEvent::Pending { position, .. }
1096                | FileDropEvent::Submit { position, .. },
1097            ) => Some(*position),
1098        }
1099    }
1100
1101    pub fn mouse_event<'a>(&'a self) -> Option<&'a dyn Any> {
1102        match self {
1103            InputEvent::KeyDown { .. } => None,
1104            InputEvent::KeyUp { .. } => None,
1105            InputEvent::ModifiersChanged { .. } => None,
1106            InputEvent::MouseDown(event) => Some(event),
1107            InputEvent::MouseUp(event) => Some(event),
1108            InputEvent::MouseMove(event) => Some(event),
1109            InputEvent::MouseExited(event) => Some(event),
1110            InputEvent::ScrollWheel(event) => Some(event),
1111            InputEvent::FileDrop(event) => Some(event),
1112        }
1113    }
1114
1115    pub fn keyboard_event<'a>(&'a self) -> Option<&'a dyn Any> {
1116        match self {
1117            InputEvent::KeyDown(event) => Some(event),
1118            InputEvent::KeyUp(event) => Some(event),
1119            InputEvent::ModifiersChanged(event) => Some(event),
1120            InputEvent::MouseDown(_) => None,
1121            InputEvent::MouseUp(_) => None,
1122            InputEvent::MouseMove(_) => None,
1123            InputEvent::MouseExited(_) => None,
1124            InputEvent::ScrollWheel(_) => None,
1125            InputEvent::FileDrop(_) => None,
1126        }
1127    }
1128}
1129
1130pub struct FocusEvent {
1131    pub blurred: Option<FocusHandle>,
1132    pub focused: Option<FocusHandle>,
1133}
1134
1135pub type MouseDownListener<V> = Box<
1136    dyn Fn(&mut V, &MouseDownEvent, &Bounds<Pixels>, DispatchPhase, &mut ViewContext<V>) + 'static,
1137>;
1138pub type MouseUpListener<V> = Box<
1139    dyn Fn(&mut V, &MouseUpEvent, &Bounds<Pixels>, DispatchPhase, &mut ViewContext<V>) + 'static,
1140>;
1141
1142pub type MouseMoveListener<V> = Box<
1143    dyn Fn(&mut V, &MouseMoveEvent, &Bounds<Pixels>, DispatchPhase, &mut ViewContext<V>) + 'static,
1144>;
1145
1146pub type ScrollWheelListener<V> = Box<
1147    dyn Fn(&mut V, &ScrollWheelEvent, &Bounds<Pixels>, DispatchPhase, &mut ViewContext<V>)
1148        + 'static,
1149>;
1150
1151pub type ClickListener<V> = Box<dyn Fn(&mut V, &ClickEvent, &mut ViewContext<V>) + 'static>;
1152
1153pub(crate) type DragListener<V> =
1154    Box<dyn Fn(&mut V, Point<Pixels>, &mut ViewContext<V>) -> AnyDrag + 'static>;
1155
1156pub(crate) type HoverListener<V> = Box<dyn Fn(&mut V, bool, &mut ViewContext<V>) + 'static>;
1157
1158pub(crate) type TooltipBuilder<V> = Box<dyn Fn(&mut V, &mut ViewContext<V>) -> AnyView + 'static>;
1159
1160pub type KeyListener<V> = Box<
1161    dyn Fn(
1162            &mut V,
1163            &dyn Any,
1164            &[&DispatchContext],
1165            DispatchPhase,
1166            &mut ViewContext<V>,
1167        ) -> Option<Box<dyn Action>>
1168        + 'static,
1169>;