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
 338pub trait ElementInteraction<V: 'static>: 'static {
 339    fn as_stateless(&self) -> &StatelessInteraction<V>;
 340    fn as_stateless_mut(&mut self) -> &mut StatelessInteraction<V>;
 341    fn as_stateful(&self) -> Option<&StatefulInteraction<V>>;
 342    fn as_stateful_mut(&mut self) -> Option<&mut StatefulInteraction<V>>;
 343
 344    fn initialize<R>(
 345        &mut self,
 346        cx: &mut ViewContext<V>,
 347        f: impl FnOnce(&mut ViewContext<V>) -> R,
 348    ) -> R {
 349        if let Some(stateful) = self.as_stateful_mut() {
 350            cx.with_element_id(stateful.id.clone(), |global_id, cx| {
 351                stateful.key_listeners.push((
 352                    TypeId::of::<KeyDownEvent>(),
 353                    Box::new(move |_, key_down, context, phase, cx| {
 354                        if phase == DispatchPhase::Bubble {
 355                            let key_down = key_down.downcast_ref::<KeyDownEvent>().unwrap();
 356                            if let KeyMatch::Some(action) =
 357                                cx.match_keystroke(&global_id, &key_down.keystroke, context)
 358                            {
 359                                return Some(action);
 360                            }
 361                        }
 362
 363                        None
 364                    }),
 365                ));
 366                let result = stateful.stateless.initialize(cx, f);
 367                stateful.key_listeners.pop();
 368                result
 369            })
 370        } else {
 371            let stateless = self.as_stateless_mut();
 372            cx.with_key_dispatch_context(stateless.dispatch_context.clone(), |cx| {
 373                cx.with_key_listeners(mem::take(&mut stateless.key_listeners), f)
 374            })
 375        }
 376    }
 377
 378    fn refine_style(
 379        &self,
 380        style: &mut Style,
 381        bounds: Bounds<Pixels>,
 382        element_state: &InteractiveElementState,
 383        cx: &mut ViewContext<V>,
 384    ) {
 385        let mouse_position = cx.mouse_position();
 386        let stateless = self.as_stateless();
 387        if let Some(group_hover) = stateless.group_hover_style.as_ref() {
 388            if let Some(group_bounds) = GroupBounds::get(&group_hover.group, cx) {
 389                if group_bounds.contains_point(&mouse_position) {
 390                    style.refine(&group_hover.style);
 391                }
 392            }
 393        }
 394        if bounds.contains_point(&mouse_position) {
 395            style.refine(&stateless.hover_style);
 396        }
 397
 398        if let Some(drag) = cx.active_drag.take() {
 399            for (state_type, group_drag_style) in &self.as_stateless().group_drag_over_styles {
 400                if let Some(group_bounds) = GroupBounds::get(&group_drag_style.group, cx) {
 401                    if *state_type == drag.view.entity_type()
 402                        && group_bounds.contains_point(&mouse_position)
 403                    {
 404                        style.refine(&group_drag_style.style);
 405                    }
 406                }
 407            }
 408
 409            for (state_type, drag_over_style) in &self.as_stateless().drag_over_styles {
 410                if *state_type == drag.view.entity_type() && bounds.contains_point(&mouse_position)
 411                {
 412                    style.refine(drag_over_style);
 413                }
 414            }
 415
 416            cx.active_drag = Some(drag);
 417        }
 418
 419        if let Some(stateful) = self.as_stateful() {
 420            let active_state = element_state.active_state.lock();
 421            if active_state.group {
 422                if let Some(group_style) = stateful.group_active_style.as_ref() {
 423                    style.refine(&group_style.style);
 424                }
 425            }
 426            if active_state.element {
 427                style.refine(&stateful.active_style);
 428            }
 429        }
 430    }
 431
 432    fn paint(
 433        &mut self,
 434        bounds: Bounds<Pixels>,
 435        content_size: Size<Pixels>,
 436        overflow: Point<Overflow>,
 437        element_state: &mut InteractiveElementState,
 438        cx: &mut ViewContext<V>,
 439    ) {
 440        let stateless = self.as_stateless_mut();
 441        for listener in stateless.mouse_down_listeners.drain(..) {
 442            cx.on_mouse_event(move |state, event: &MouseDownEvent, phase, cx| {
 443                listener(state, event, &bounds, phase, cx);
 444            })
 445        }
 446
 447        for listener in stateless.mouse_up_listeners.drain(..) {
 448            cx.on_mouse_event(move |state, event: &MouseUpEvent, phase, cx| {
 449                listener(state, event, &bounds, phase, cx);
 450            })
 451        }
 452
 453        for listener in stateless.mouse_move_listeners.drain(..) {
 454            cx.on_mouse_event(move |state, event: &MouseMoveEvent, phase, cx| {
 455                listener(state, event, &bounds, phase, cx);
 456            })
 457        }
 458
 459        for listener in stateless.scroll_wheel_listeners.drain(..) {
 460            cx.on_mouse_event(move |state, event: &ScrollWheelEvent, phase, cx| {
 461                listener(state, event, &bounds, phase, cx);
 462            })
 463        }
 464
 465        let hover_group_bounds = stateless
 466            .group_hover_style
 467            .as_ref()
 468            .and_then(|group_hover| GroupBounds::get(&group_hover.group, cx));
 469
 470        if let Some(group_bounds) = hover_group_bounds {
 471            let hovered = group_bounds.contains_point(&cx.mouse_position());
 472            cx.on_mouse_event(move |_, event: &MouseMoveEvent, phase, cx| {
 473                if phase == DispatchPhase::Capture {
 474                    if group_bounds.contains_point(&event.position) != hovered {
 475                        cx.notify();
 476                    }
 477                }
 478            });
 479        }
 480
 481        if stateless.hover_style.is_some()
 482            || (cx.active_drag.is_some() && !stateless.drag_over_styles.is_empty())
 483        {
 484            let hovered = bounds.contains_point(&cx.mouse_position());
 485            cx.on_mouse_event(move |_, event: &MouseMoveEvent, phase, cx| {
 486                if phase == DispatchPhase::Capture {
 487                    if bounds.contains_point(&event.position) != hovered {
 488                        cx.notify();
 489                    }
 490                }
 491            });
 492        }
 493
 494        if cx.active_drag.is_some() {
 495            let drop_listeners = mem::take(&mut stateless.drop_listeners);
 496            cx.on_mouse_event(move |view, event: &MouseUpEvent, phase, cx| {
 497                if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position) {
 498                    if let Some(drag_state_type) =
 499                        cx.active_drag.as_ref().map(|drag| drag.view.entity_type())
 500                    {
 501                        for (drop_state_type, listener) in &drop_listeners {
 502                            if *drop_state_type == drag_state_type {
 503                                let drag = cx
 504                                    .active_drag
 505                                    .take()
 506                                    .expect("checked for type drag state type above");
 507                                listener(view, drag.view.clone(), cx);
 508                                cx.notify();
 509                                cx.stop_propagation();
 510                            }
 511                        }
 512                    }
 513                }
 514            });
 515        }
 516
 517        if let Some(stateful) = self.as_stateful_mut() {
 518            let click_listeners = mem::take(&mut stateful.click_listeners);
 519            let drag_listener = mem::take(&mut stateful.drag_listener);
 520
 521            if !click_listeners.is_empty() || drag_listener.is_some() {
 522                let pending_mouse_down = element_state.pending_mouse_down.clone();
 523                let mouse_down = pending_mouse_down.lock().clone();
 524                if let Some(mouse_down) = mouse_down {
 525                    if let Some(drag_listener) = drag_listener {
 526                        let active_state = element_state.active_state.clone();
 527
 528                        cx.on_mouse_event(move |view_state, event: &MouseMoveEvent, phase, cx| {
 529                            if cx.active_drag.is_some() {
 530                                if phase == DispatchPhase::Capture {
 531                                    cx.notify();
 532                                }
 533                            } else if phase == DispatchPhase::Bubble
 534                                && bounds.contains_point(&event.position)
 535                                && (event.position - mouse_down.position).magnitude()
 536                                    > DRAG_THRESHOLD
 537                            {
 538                                *active_state.lock() = ActiveState::default();
 539                                let cursor_offset = event.position - bounds.origin;
 540                                let drag = drag_listener(view_state, cursor_offset, cx);
 541                                cx.active_drag = Some(drag);
 542                                cx.notify();
 543                                cx.stop_propagation();
 544                            }
 545                        });
 546                    }
 547
 548                    cx.on_mouse_event(move |view_state, event: &MouseUpEvent, phase, cx| {
 549                        if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position)
 550                        {
 551                            let mouse_click = ClickEvent {
 552                                down: mouse_down.clone(),
 553                                up: event.clone(),
 554                            };
 555                            for listener in &click_listeners {
 556                                listener(view_state, &mouse_click, cx);
 557                            }
 558                        }
 559                        *pending_mouse_down.lock() = None;
 560                    });
 561                } else {
 562                    cx.on_mouse_event(move |_state, event: &MouseDownEvent, phase, _cx| {
 563                        if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position)
 564                        {
 565                            *pending_mouse_down.lock() = Some(event.clone());
 566                        }
 567                    });
 568                }
 569            }
 570
 571            let active_state = element_state.active_state.clone();
 572            if active_state.lock().is_none() {
 573                let active_group_bounds = stateful
 574                    .group_active_style
 575                    .as_ref()
 576                    .and_then(|group_active| GroupBounds::get(&group_active.group, cx));
 577                cx.on_mouse_event(move |_view, down: &MouseDownEvent, phase, cx| {
 578                    if phase == DispatchPhase::Bubble {
 579                        let group = active_group_bounds
 580                            .map_or(false, |bounds| bounds.contains_point(&down.position));
 581                        let element = bounds.contains_point(&down.position);
 582                        if group || element {
 583                            *active_state.lock() = ActiveState { group, element };
 584                            cx.notify();
 585                        }
 586                    }
 587                });
 588            } else {
 589                cx.on_mouse_event(move |_, _: &MouseUpEvent, phase, cx| {
 590                    if phase == DispatchPhase::Capture {
 591                        *active_state.lock() = ActiveState::default();
 592                        cx.notify();
 593                    }
 594                });
 595            }
 596
 597            if overflow.x == Overflow::Scroll || overflow.y == Overflow::Scroll {
 598                let scroll_offset = element_state
 599                    .scroll_offset
 600                    .get_or_insert_with(Arc::default)
 601                    .clone();
 602                let line_height = cx.line_height();
 603                let scroll_max = (content_size - bounds.size).max(&Size::default());
 604
 605                cx.on_mouse_event(move |_, event: &ScrollWheelEvent, phase, cx| {
 606                    if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position) {
 607                        let mut scroll_offset = scroll_offset.lock();
 608                        let old_scroll_offset = *scroll_offset;
 609                        let delta = event.delta.pixel_delta(line_height);
 610
 611                        if overflow.x == Overflow::Scroll {
 612                            scroll_offset.x =
 613                                (scroll_offset.x + delta.x).clamp(-scroll_max.width, px(0.));
 614                        }
 615
 616                        if overflow.y == Overflow::Scroll {
 617                            scroll_offset.y =
 618                                (scroll_offset.y + delta.y).clamp(-scroll_max.height, px(0.));
 619                        }
 620
 621                        if *scroll_offset != old_scroll_offset {
 622                            cx.notify();
 623                            cx.stop_propagation();
 624                        }
 625                    }
 626                });
 627            }
 628        }
 629    }
 630}
 631
 632#[derive(Deref, DerefMut)]
 633pub struct StatefulInteraction<V> {
 634    pub id: ElementId,
 635    #[deref]
 636    #[deref_mut]
 637    stateless: StatelessInteraction<V>,
 638    click_listeners: SmallVec<[ClickListener<V>; 2]>,
 639    active_style: StyleRefinement,
 640    group_active_style: Option<GroupStyle>,
 641    drag_listener: Option<DragListener<V>>,
 642}
 643
 644impl<V: 'static> ElementInteraction<V> for StatefulInteraction<V> {
 645    fn as_stateful(&self) -> Option<&StatefulInteraction<V>> {
 646        Some(self)
 647    }
 648
 649    fn as_stateful_mut(&mut self) -> Option<&mut StatefulInteraction<V>> {
 650        Some(self)
 651    }
 652
 653    fn as_stateless(&self) -> &StatelessInteraction<V> {
 654        &self.stateless
 655    }
 656
 657    fn as_stateless_mut(&mut self) -> &mut StatelessInteraction<V> {
 658        &mut self.stateless
 659    }
 660}
 661
 662impl<V> From<ElementId> for StatefulInteraction<V> {
 663    fn from(id: ElementId) -> Self {
 664        Self {
 665            id,
 666            stateless: StatelessInteraction::default(),
 667            click_listeners: SmallVec::new(),
 668            drag_listener: None,
 669            active_style: StyleRefinement::default(),
 670            group_active_style: None,
 671        }
 672    }
 673}
 674
 675type DropListener<V> = dyn Fn(&mut V, AnyView, &mut ViewContext<V>) + 'static;
 676
 677pub struct StatelessInteraction<V> {
 678    pub dispatch_context: DispatchContext,
 679    pub mouse_down_listeners: SmallVec<[MouseDownListener<V>; 2]>,
 680    pub mouse_up_listeners: SmallVec<[MouseUpListener<V>; 2]>,
 681    pub mouse_move_listeners: SmallVec<[MouseMoveListener<V>; 2]>,
 682    pub scroll_wheel_listeners: SmallVec<[ScrollWheelListener<V>; 2]>,
 683    pub key_listeners: SmallVec<[(TypeId, KeyListener<V>); 32]>,
 684    pub hover_style: StyleRefinement,
 685    pub group_hover_style: Option<GroupStyle>,
 686    drag_over_styles: SmallVec<[(TypeId, StyleRefinement); 2]>,
 687    group_drag_over_styles: SmallVec<[(TypeId, GroupStyle); 2]>,
 688    drop_listeners: SmallVec<[(TypeId, Box<DropListener<V>>); 2]>,
 689}
 690
 691impl<V> StatelessInteraction<V> {
 692    pub fn into_stateful(self, id: impl Into<ElementId>) -> StatefulInteraction<V> {
 693        StatefulInteraction {
 694            id: id.into(),
 695            stateless: self,
 696            click_listeners: SmallVec::new(),
 697            drag_listener: None,
 698            active_style: StyleRefinement::default(),
 699            group_active_style: None,
 700        }
 701    }
 702}
 703
 704pub struct GroupStyle {
 705    pub group: SharedString,
 706    pub style: StyleRefinement,
 707}
 708
 709#[derive(Default)]
 710pub struct GroupBounds(HashMap<SharedString, SmallVec<[Bounds<Pixels>; 1]>>);
 711
 712impl GroupBounds {
 713    pub fn get(name: &SharedString, cx: &mut AppContext) -> Option<Bounds<Pixels>> {
 714        cx.default_global::<Self>()
 715            .0
 716            .get(name)
 717            .and_then(|bounds_stack| bounds_stack.last())
 718            .cloned()
 719    }
 720
 721    pub fn push(name: SharedString, bounds: Bounds<Pixels>, cx: &mut AppContext) {
 722        cx.default_global::<Self>()
 723            .0
 724            .entry(name)
 725            .or_default()
 726            .push(bounds);
 727    }
 728
 729    pub fn pop(name: &SharedString, cx: &mut AppContext) {
 730        cx.default_global::<Self>().0.get_mut(name).unwrap().pop();
 731    }
 732}
 733
 734#[derive(Copy, Clone, Default, Eq, PartialEq)]
 735struct ActiveState {
 736    pub group: bool,
 737    pub element: bool,
 738}
 739
 740impl ActiveState {
 741    pub fn is_none(&self) -> bool {
 742        !self.group && !self.element
 743    }
 744}
 745
 746#[derive(Default)]
 747pub struct InteractiveElementState {
 748    active_state: Arc<Mutex<ActiveState>>,
 749    pending_mouse_down: Arc<Mutex<Option<MouseDownEvent>>>,
 750    scroll_offset: Option<Arc<Mutex<Point<Pixels>>>>,
 751}
 752
 753impl InteractiveElementState {
 754    pub fn scroll_offset(&self) -> Option<Point<Pixels>> {
 755        self.scroll_offset
 756            .as_ref()
 757            .map(|offset| offset.lock().clone())
 758    }
 759}
 760
 761impl<V> Default for StatelessInteraction<V> {
 762    fn default() -> Self {
 763        Self {
 764            dispatch_context: DispatchContext::default(),
 765            mouse_down_listeners: SmallVec::new(),
 766            mouse_up_listeners: SmallVec::new(),
 767            mouse_move_listeners: SmallVec::new(),
 768            scroll_wheel_listeners: SmallVec::new(),
 769            key_listeners: SmallVec::new(),
 770            hover_style: StyleRefinement::default(),
 771            group_hover_style: None,
 772            drag_over_styles: SmallVec::new(),
 773            group_drag_over_styles: SmallVec::new(),
 774            drop_listeners: SmallVec::new(),
 775        }
 776    }
 777}
 778
 779impl<V: 'static> ElementInteraction<V> for StatelessInteraction<V> {
 780    fn as_stateful(&self) -> Option<&StatefulInteraction<V>> {
 781        None
 782    }
 783
 784    fn as_stateful_mut(&mut self) -> Option<&mut StatefulInteraction<V>> {
 785        None
 786    }
 787
 788    fn as_stateless(&self) -> &StatelessInteraction<V> {
 789        self
 790    }
 791
 792    fn as_stateless_mut(&mut self) -> &mut StatelessInteraction<V> {
 793        self
 794    }
 795}
 796
 797#[derive(Clone, Debug, Eq, PartialEq)]
 798pub struct KeyDownEvent {
 799    pub keystroke: Keystroke,
 800    pub is_held: bool,
 801}
 802
 803#[derive(Clone, Debug)]
 804pub struct KeyUpEvent {
 805    pub keystroke: Keystroke,
 806}
 807
 808#[derive(Clone, Debug, Default)]
 809pub struct ModifiersChangedEvent {
 810    pub modifiers: Modifiers,
 811}
 812
 813impl Deref for ModifiersChangedEvent {
 814    type Target = Modifiers;
 815
 816    fn deref(&self) -> &Self::Target {
 817        &self.modifiers
 818    }
 819}
 820
 821/// The phase of a touch motion event.
 822/// Based on the winit enum of the same name.
 823#[derive(Clone, Copy, Debug)]
 824pub enum TouchPhase {
 825    Started,
 826    Moved,
 827    Ended,
 828}
 829
 830#[derive(Clone, Debug, Default)]
 831pub struct MouseDownEvent {
 832    pub button: MouseButton,
 833    pub position: Point<Pixels>,
 834    pub modifiers: Modifiers,
 835    pub click_count: usize,
 836}
 837
 838#[derive(Clone, Debug, Default)]
 839pub struct MouseUpEvent {
 840    pub button: MouseButton,
 841    pub position: Point<Pixels>,
 842    pub modifiers: Modifiers,
 843    pub click_count: usize,
 844}
 845
 846#[derive(Clone, Debug, Default)]
 847pub struct ClickEvent {
 848    pub down: MouseDownEvent,
 849    pub up: MouseUpEvent,
 850}
 851
 852pub struct Drag<S, R, V, E>
 853where
 854    R: Fn(&mut V, &mut ViewContext<V>) -> E,
 855    V: 'static,
 856    E: Component<()>,
 857{
 858    pub state: S,
 859    pub render_drag_handle: R,
 860    view_type: PhantomData<V>,
 861}
 862
 863impl<S, R, V, E> Drag<S, R, V, E>
 864where
 865    R: Fn(&mut V, &mut ViewContext<V>) -> E,
 866    V: 'static,
 867    E: Component<()>,
 868{
 869    pub fn new(state: S, render_drag_handle: R) -> Self {
 870        Drag {
 871            state,
 872            render_drag_handle,
 873            view_type: PhantomData,
 874        }
 875    }
 876}
 877
 878// impl<S, R, V, E> Render for Drag<S, R, V, E> {
 879//     // fn render(&mut self, cx: ViewContext<Self>) ->
 880// }
 881
 882#[derive(Hash, PartialEq, Eq, Copy, Clone, Debug)]
 883pub enum MouseButton {
 884    Left,
 885    Right,
 886    Middle,
 887    Navigate(NavigationDirection),
 888}
 889
 890impl MouseButton {
 891    pub fn all() -> Vec<Self> {
 892        vec![
 893            MouseButton::Left,
 894            MouseButton::Right,
 895            MouseButton::Middle,
 896            MouseButton::Navigate(NavigationDirection::Back),
 897            MouseButton::Navigate(NavigationDirection::Forward),
 898        ]
 899    }
 900}
 901
 902impl Default for MouseButton {
 903    fn default() -> Self {
 904        Self::Left
 905    }
 906}
 907
 908#[derive(Hash, PartialEq, Eq, Copy, Clone, Debug)]
 909pub enum NavigationDirection {
 910    Back,
 911    Forward,
 912}
 913
 914impl Default for NavigationDirection {
 915    fn default() -> Self {
 916        Self::Back
 917    }
 918}
 919
 920#[derive(Clone, Debug, Default)]
 921pub struct MouseMoveEvent {
 922    pub position: Point<Pixels>,
 923    pub pressed_button: Option<MouseButton>,
 924    pub modifiers: Modifiers,
 925}
 926
 927#[derive(Clone, Debug)]
 928pub struct ScrollWheelEvent {
 929    pub position: Point<Pixels>,
 930    pub delta: ScrollDelta,
 931    pub modifiers: Modifiers,
 932    pub touch_phase: TouchPhase,
 933}
 934
 935impl Deref for ScrollWheelEvent {
 936    type Target = Modifiers;
 937
 938    fn deref(&self) -> &Self::Target {
 939        &self.modifiers
 940    }
 941}
 942
 943#[derive(Clone, Copy, Debug)]
 944pub enum ScrollDelta {
 945    Pixels(Point<Pixels>),
 946    Lines(Point<f32>),
 947}
 948
 949impl Default for ScrollDelta {
 950    fn default() -> Self {
 951        Self::Lines(Default::default())
 952    }
 953}
 954
 955impl ScrollDelta {
 956    pub fn precise(&self) -> bool {
 957        match self {
 958            ScrollDelta::Pixels(_) => true,
 959            ScrollDelta::Lines(_) => false,
 960        }
 961    }
 962
 963    pub fn pixel_delta(&self, line_height: Pixels) -> Point<Pixels> {
 964        match self {
 965            ScrollDelta::Pixels(delta) => *delta,
 966            ScrollDelta::Lines(delta) => point(line_height * delta.x, line_height * delta.y),
 967        }
 968    }
 969}
 970
 971#[derive(Clone, Debug, Default)]
 972pub struct MouseExitEvent {
 973    pub position: Point<Pixels>,
 974    pub pressed_button: Option<MouseButton>,
 975    pub modifiers: Modifiers,
 976}
 977
 978impl Deref for MouseExitEvent {
 979    type Target = Modifiers;
 980
 981    fn deref(&self) -> &Self::Target {
 982        &self.modifiers
 983    }
 984}
 985
 986#[derive(Debug, Clone, Default)]
 987pub struct ExternalPaths(pub(crate) SmallVec<[PathBuf; 2]>);
 988
 989impl Render for ExternalPaths {
 990    type Element = Div<Self>;
 991
 992    fn render(&mut self, _: &mut ViewContext<Self>) -> Self::Element {
 993        div() // Intentionally left empty because the platform will render icons for the dragged files
 994    }
 995}
 996
 997#[derive(Debug, Clone)]
 998pub enum FileDropEvent {
 999    Entered {
1000        position: Point<Pixels>,
1001        files: ExternalPaths,
1002    },
1003    Pending {
1004        position: Point<Pixels>,
1005    },
1006    Submit {
1007        position: Point<Pixels>,
1008    },
1009    Exited,
1010}
1011
1012#[derive(Clone, Debug)]
1013pub enum InputEvent {
1014    KeyDown(KeyDownEvent),
1015    KeyUp(KeyUpEvent),
1016    ModifiersChanged(ModifiersChangedEvent),
1017    MouseDown(MouseDownEvent),
1018    MouseUp(MouseUpEvent),
1019    MouseMove(MouseMoveEvent),
1020    MouseExited(MouseExitEvent),
1021    ScrollWheel(ScrollWheelEvent),
1022    FileDrop(FileDropEvent),
1023}
1024
1025impl InputEvent {
1026    pub fn position(&self) -> Option<Point<Pixels>> {
1027        match self {
1028            InputEvent::KeyDown { .. } => None,
1029            InputEvent::KeyUp { .. } => None,
1030            InputEvent::ModifiersChanged { .. } => None,
1031            InputEvent::MouseDown(event) => Some(event.position),
1032            InputEvent::MouseUp(event) => Some(event.position),
1033            InputEvent::MouseMove(event) => Some(event.position),
1034            InputEvent::MouseExited(event) => Some(event.position),
1035            InputEvent::ScrollWheel(event) => Some(event.position),
1036            InputEvent::FileDrop(FileDropEvent::Exited) => None,
1037            InputEvent::FileDrop(
1038                FileDropEvent::Entered { position, .. }
1039                | FileDropEvent::Pending { position, .. }
1040                | FileDropEvent::Submit { position, .. },
1041            ) => Some(*position),
1042        }
1043    }
1044
1045    pub fn mouse_event<'a>(&'a self) -> Option<&'a dyn Any> {
1046        match self {
1047            InputEvent::KeyDown { .. } => None,
1048            InputEvent::KeyUp { .. } => None,
1049            InputEvent::ModifiersChanged { .. } => None,
1050            InputEvent::MouseDown(event) => Some(event),
1051            InputEvent::MouseUp(event) => Some(event),
1052            InputEvent::MouseMove(event) => Some(event),
1053            InputEvent::MouseExited(event) => Some(event),
1054            InputEvent::ScrollWheel(event) => Some(event),
1055            InputEvent::FileDrop(event) => Some(event),
1056        }
1057    }
1058
1059    pub fn keyboard_event<'a>(&'a self) -> Option<&'a dyn Any> {
1060        match self {
1061            InputEvent::KeyDown(event) => Some(event),
1062            InputEvent::KeyUp(event) => Some(event),
1063            InputEvent::ModifiersChanged(event) => Some(event),
1064            InputEvent::MouseDown(_) => None,
1065            InputEvent::MouseUp(_) => None,
1066            InputEvent::MouseMove(_) => None,
1067            InputEvent::MouseExited(_) => None,
1068            InputEvent::ScrollWheel(_) => None,
1069            InputEvent::FileDrop(_) => None,
1070        }
1071    }
1072}
1073
1074pub struct FocusEvent {
1075    pub blurred: Option<FocusHandle>,
1076    pub focused: Option<FocusHandle>,
1077}
1078
1079pub type MouseDownListener<V> = Box<
1080    dyn Fn(&mut V, &MouseDownEvent, &Bounds<Pixels>, DispatchPhase, &mut ViewContext<V>) + 'static,
1081>;
1082pub type MouseUpListener<V> = Box<
1083    dyn Fn(&mut V, &MouseUpEvent, &Bounds<Pixels>, DispatchPhase, &mut ViewContext<V>) + 'static,
1084>;
1085
1086pub type MouseMoveListener<V> = Box<
1087    dyn Fn(&mut V, &MouseMoveEvent, &Bounds<Pixels>, DispatchPhase, &mut ViewContext<V>) + 'static,
1088>;
1089
1090pub type ScrollWheelListener<V> = Box<
1091    dyn Fn(&mut V, &ScrollWheelEvent, &Bounds<Pixels>, DispatchPhase, &mut ViewContext<V>)
1092        + 'static,
1093>;
1094
1095pub type ClickListener<V> = Box<dyn Fn(&mut V, &ClickEvent, &mut ViewContext<V>) + 'static>;
1096
1097pub(crate) type DragListener<V> =
1098    Box<dyn Fn(&mut V, Point<Pixels>, &mut ViewContext<V>) -> AnyDrag + 'static>;
1099
1100pub type KeyListener<V> = Box<
1101    dyn Fn(
1102            &mut V,
1103            &dyn Any,
1104            &[&DispatchContext],
1105            DispatchPhase,
1106            &mut ViewContext<V>,
1107        ) -> Option<Box<dyn Action>>
1108        + 'static,
1109>;