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 point, px, size, Action, AnyDrag, AnyElement, AnyTooltip, AnyView, AppContext, Bounds,
20 ClickEvent, DispatchPhase, Element, ElementContext, ElementId, FocusHandle, Global, Hitbox,
21 HitboxId, IntoElement, IsZero, KeyContext, KeyDownEvent, KeyUpEvent, LayoutId, MouseButton,
22 MouseDownEvent, MouseMoveEvent, MouseUpEvent, ParentElement, Pixels, Point, Render,
23 ScrollWheelEvent, SharedString, Size, Style, StyleRefinement, Styled, Task, View, Visibility,
24 WindowContext,
25};
26use collections::HashMap;
27use refineable::Refineable;
28use smallvec::SmallVec;
29use std::{
30 any::{Any, TypeId},
31 cell::RefCell,
32 cmp::Ordering,
33 fmt::Debug,
34 marker::PhantomData,
35 mem,
36 ops::DerefMut,
37 rc::Rc,
38 time::Duration,
39};
40use taffy::style::Overflow;
41use util::ResultExt;
42
43const DRAG_THRESHOLD: f64 = 2.;
44pub(crate) const TOOLTIP_DELAY: Duration = Duration::from_millis(500);
45
46/// The styling information for a given group.
47pub struct GroupStyle {
48 /// The identifier for this group.
49 pub group: SharedString,
50
51 /// The specific style refinement that this group would apply
52 /// to its children.
53 pub style: Box<StyleRefinement>,
54}
55
56/// An event for when a drag is moving over this element, with the given state type.
57pub struct DragMoveEvent<T> {
58 /// The mouse move event that triggered this drag move event.
59 pub event: MouseMoveEvent,
60
61 /// The bounds of this element.
62 pub bounds: Bounds<Pixels>,
63 drag: PhantomData<T>,
64}
65
66impl<T: 'static> DragMoveEvent<T> {
67 /// Returns the drag state for this event.
68 pub fn drag<'b>(&self, cx: &'b AppContext) -> &'b T {
69 cx.active_drag
70 .as_ref()
71 .and_then(|drag| drag.value.downcast_ref::<T>())
72 .expect("DragMoveEvent is only valid when the stored active drag is of the same type.")
73 }
74}
75
76impl Interactivity {
77 /// Bind the given callback to the mouse down event for the given mouse button, during the bubble phase
78 /// The imperative API equivalent of [`InteractiveElement::on_mouse_down`]
79 ///
80 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to the view state from this callback.
81 pub fn on_mouse_down(
82 &mut self,
83 button: MouseButton,
84 listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
85 ) {
86 self.mouse_down_listeners
87 .push(Box::new(move |event, phase, hitbox, cx| {
88 if phase == DispatchPhase::Bubble && event.button == button && hitbox.is_hovered(cx)
89 {
90 (listener)(event, cx)
91 }
92 }));
93 }
94
95 /// Bind the given callback to the mouse down event for any button, during the capture phase
96 /// The imperative API equivalent of [`InteractiveElement::capture_any_mouse_down`]
97 ///
98 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
99 pub fn capture_any_mouse_down(
100 &mut self,
101 listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
102 ) {
103 self.mouse_down_listeners
104 .push(Box::new(move |event, phase, hitbox, cx| {
105 if phase == DispatchPhase::Capture && hitbox.is_hovered(cx) {
106 (listener)(event, cx)
107 }
108 }));
109 }
110
111 /// Bind the given callback to the mouse down event for any button, during the bubble phase
112 /// the imperative API equivalent to [`InteractiveElement::on_any_mouse_down`]
113 ///
114 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
115 pub fn on_any_mouse_down(
116 &mut self,
117 listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
118 ) {
119 self.mouse_down_listeners
120 .push(Box::new(move |event, phase, hitbox, cx| {
121 if phase == DispatchPhase::Bubble && hitbox.is_hovered(cx) {
122 (listener)(event, cx)
123 }
124 }));
125 }
126
127 /// Bind the given callback to the mouse up event for the given button, during the bubble phase
128 /// the imperative API equivalent to [`InteractiveElement::on_mouse_up`]
129 ///
130 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
131 pub fn on_mouse_up(
132 &mut self,
133 button: MouseButton,
134 listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
135 ) {
136 self.mouse_up_listeners
137 .push(Box::new(move |event, phase, hitbox, cx| {
138 if phase == DispatchPhase::Bubble && event.button == button && hitbox.is_hovered(cx)
139 {
140 (listener)(event, cx)
141 }
142 }));
143 }
144
145 /// Bind the given callback to the mouse up event for any button, during the capture phase
146 /// the imperative API equivalent to [`InteractiveElement::capture_any_mouse_up`]
147 ///
148 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
149 pub fn capture_any_mouse_up(
150 &mut self,
151 listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
152 ) {
153 self.mouse_up_listeners
154 .push(Box::new(move |event, phase, hitbox, cx| {
155 if phase == DispatchPhase::Capture && hitbox.is_hovered(cx) {
156 (listener)(event, cx)
157 }
158 }));
159 }
160
161 /// Bind the given callback to the mouse up event for any button, during the bubble phase
162 /// the imperative API equivalent to [`Interactivity::on_any_mouse_up`]
163 ///
164 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
165 pub fn on_any_mouse_up(
166 &mut self,
167 listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
168 ) {
169 self.mouse_up_listeners
170 .push(Box::new(move |event, phase, hitbox, cx| {
171 if phase == DispatchPhase::Bubble && hitbox.is_hovered(cx) {
172 (listener)(event, cx)
173 }
174 }));
175 }
176
177 /// Bind the given callback to the mouse down event, on any button, during the capture phase,
178 /// when the mouse is outside of the bounds of this element.
179 /// The imperative API equivalent to [`InteractiveElement::on_mouse_down_out`]
180 ///
181 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
182 pub fn on_mouse_down_out(
183 &mut self,
184 listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
185 ) {
186 self.mouse_down_listeners
187 .push(Box::new(move |event, phase, hitbox, cx| {
188 if phase == DispatchPhase::Capture && !hitbox.contains(&cx.mouse_position()) {
189 (listener)(event, cx)
190 }
191 }));
192 }
193
194 /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
195 /// when the mouse is outside of the bounds of this element.
196 /// The imperative API equivalent to [`InteractiveElement::on_mouse_up_out`]
197 ///
198 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
199 pub fn on_mouse_up_out(
200 &mut self,
201 button: MouseButton,
202 listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
203 ) {
204 self.mouse_up_listeners
205 .push(Box::new(move |event, phase, hitbox, cx| {
206 if phase == DispatchPhase::Capture
207 && event.button == button
208 && !hitbox.is_hovered(cx)
209 {
210 (listener)(event, cx);
211 }
212 }));
213 }
214
215 /// Bind the given callback to the mouse move event, during the bubble phase
216 /// The imperative API equivalent to [`InteractiveElement::on_mouse_move`]
217 ///
218 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
219 pub fn on_mouse_move(
220 &mut self,
221 listener: impl Fn(&MouseMoveEvent, &mut WindowContext) + 'static,
222 ) {
223 self.mouse_move_listeners
224 .push(Box::new(move |event, phase, hitbox, cx| {
225 if phase == DispatchPhase::Bubble && hitbox.is_hovered(cx) {
226 (listener)(event, cx);
227 }
228 }));
229 }
230
231 /// Bind the given callback to the mouse drag event of the given type. Note that this
232 /// will be called for all move events, inside or outside of this element, as long as the
233 /// drag was started with this element under the mouse. Useful for implementing draggable
234 /// UIs that don't conform to a drag and drop style interaction, like resizing.
235 /// The imperative API equivalent to [`InteractiveElement::on_drag_move`]
236 ///
237 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
238 pub fn on_drag_move<T>(
239 &mut self,
240 listener: impl Fn(&DragMoveEvent<T>, &mut WindowContext) + 'static,
241 ) where
242 T: 'static,
243 {
244 self.mouse_move_listeners
245 .push(Box::new(move |event, phase, hitbox, cx| {
246 if phase == DispatchPhase::Capture
247 && cx
248 .active_drag
249 .as_ref()
250 .is_some_and(|drag| drag.value.as_ref().type_id() == TypeId::of::<T>())
251 {
252 (listener)(
253 &DragMoveEvent {
254 event: event.clone(),
255 bounds: hitbox.bounds,
256 drag: PhantomData,
257 },
258 cx,
259 );
260 }
261 }));
262 }
263
264 /// Bind the given callback to scroll wheel events during the bubble phase
265 /// The imperative API equivalent to [`InteractiveElement::on_scroll_wheel`]
266 ///
267 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
268 pub fn on_scroll_wheel(
269 &mut self,
270 listener: impl Fn(&ScrollWheelEvent, &mut WindowContext) + 'static,
271 ) {
272 self.scroll_wheel_listeners
273 .push(Box::new(move |event, phase, hitbox, cx| {
274 if phase == DispatchPhase::Bubble && hitbox.is_hovered(cx) {
275 (listener)(event, cx);
276 }
277 }));
278 }
279
280 /// Bind the given callback to an action dispatch during the capture phase
281 /// The imperative API equivalent to [`InteractiveElement::capture_action`]
282 ///
283 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
284 pub fn capture_action<A: Action>(
285 &mut self,
286 listener: impl Fn(&A, &mut WindowContext) + 'static,
287 ) {
288 self.action_listeners.push((
289 TypeId::of::<A>(),
290 Box::new(move |action, phase, cx| {
291 let action = action.downcast_ref().unwrap();
292 if phase == DispatchPhase::Capture {
293 (listener)(action, cx)
294 }
295 }),
296 ));
297 }
298
299 /// Bind the given callback to an action dispatch during the bubble phase
300 /// The imperative API equivalent to [`InteractiveElement::on_action`]
301 ///
302 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
303 pub fn on_action<A: Action>(&mut self, listener: impl Fn(&A, &mut WindowContext) + 'static) {
304 self.action_listeners.push((
305 TypeId::of::<A>(),
306 Box::new(move |action, phase, cx| {
307 let action = action.downcast_ref().unwrap();
308 if phase == DispatchPhase::Bubble {
309 (listener)(action, cx)
310 }
311 }),
312 ));
313 }
314
315 /// Bind the given callback to an action dispatch, based on a dynamic action parameter
316 /// instead of a type parameter. Useful for component libraries that want to expose
317 /// action bindings to their users.
318 /// The imperative API equivalent to [`InteractiveElement::on_boxed_action`]
319 ///
320 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
321 pub fn on_boxed_action(
322 &mut self,
323 action: &dyn Action,
324 listener: impl Fn(&Box<dyn Action>, &mut WindowContext) + 'static,
325 ) {
326 let action = action.boxed_clone();
327 self.action_listeners.push((
328 (*action).type_id(),
329 Box::new(move |_, phase, cx| {
330 if phase == DispatchPhase::Bubble {
331 (listener)(&action, cx)
332 }
333 }),
334 ));
335 }
336
337 /// Bind the given callback to key down events during the bubble phase
338 /// The imperative API equivalent to [`InteractiveElement::on_key_down`]
339 ///
340 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
341 pub fn on_key_down(&mut self, listener: impl Fn(&KeyDownEvent, &mut WindowContext) + 'static) {
342 self.key_down_listeners
343 .push(Box::new(move |event, phase, cx| {
344 if phase == DispatchPhase::Bubble {
345 (listener)(event, cx)
346 }
347 }));
348 }
349
350 /// Bind the given callback to key down events during the capture phase
351 /// The imperative API equivalent to [`InteractiveElement::capture_key_down`]
352 ///
353 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
354 pub fn capture_key_down(
355 &mut self,
356 listener: impl Fn(&KeyDownEvent, &mut WindowContext) + 'static,
357 ) {
358 self.key_down_listeners
359 .push(Box::new(move |event, phase, cx| {
360 if phase == DispatchPhase::Capture {
361 listener(event, cx)
362 }
363 }));
364 }
365
366 /// Bind the given callback to key up events during the bubble phase
367 /// The imperative API equivalent to [`InteractiveElement::on_key_up`]
368 ///
369 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
370 pub fn on_key_up(&mut self, listener: impl Fn(&KeyUpEvent, &mut WindowContext) + 'static) {
371 self.key_up_listeners
372 .push(Box::new(move |event, phase, cx| {
373 if phase == DispatchPhase::Bubble {
374 listener(event, cx)
375 }
376 }));
377 }
378
379 /// Bind the given callback to key up events during the capture phase
380 /// The imperative API equivalent to [`InteractiveElement::on_key_up`]
381 ///
382 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
383 pub fn capture_key_up(&mut self, listener: impl Fn(&KeyUpEvent, &mut WindowContext) + 'static) {
384 self.key_up_listeners
385 .push(Box::new(move |event, phase, cx| {
386 if phase == DispatchPhase::Capture {
387 listener(event, cx)
388 }
389 }));
390 }
391
392 /// Bind the given callback to drop events of the given type, whether or not the drag started on this element
393 /// The imperative API equivalent to [`InteractiveElement::on_drop`]
394 ///
395 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
396 pub fn on_drop<T: 'static>(&mut self, listener: impl Fn(&T, &mut WindowContext) + 'static) {
397 self.drop_listeners.push((
398 TypeId::of::<T>(),
399 Box::new(move |dragged_value, cx| {
400 listener(dragged_value.downcast_ref().unwrap(), cx);
401 }),
402 ));
403 }
404
405 /// Use the given predicate to determine whether or not a drop event should be dispatched to this element
406 /// The imperative API equivalent to [`InteractiveElement::can_drop`]
407 pub fn can_drop(&mut self, predicate: impl Fn(&dyn Any, &mut WindowContext) -> bool + 'static) {
408 self.can_drop_predicate = Some(Box::new(predicate));
409 }
410
411 /// Bind the given callback to click events of this element
412 /// The imperative API equivalent to [`StatefulInteractiveElement::on_click`]
413 ///
414 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
415 pub fn on_click(&mut self, listener: impl Fn(&ClickEvent, &mut WindowContext) + 'static)
416 where
417 Self: Sized,
418 {
419 self.click_listeners
420 .push(Box::new(move |event, cx| listener(event, cx)));
421 }
422
423 /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
424 /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
425 /// the [`Self::on_drag_move`] API
426 /// The imperative API equivalent to [`StatefulInteractiveElement::on_drag`]
427 ///
428 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
429 pub fn on_drag<T, W>(
430 &mut self,
431 value: T,
432 constructor: impl Fn(&T, &mut WindowContext) -> View<W> + 'static,
433 ) where
434 Self: Sized,
435 T: 'static,
436 W: 'static + Render,
437 {
438 debug_assert!(
439 self.drag_listener.is_none(),
440 "calling on_drag more than once on the same element is not supported"
441 );
442 self.drag_listener = Some((
443 Box::new(value),
444 Box::new(move |value, cx| constructor(value.downcast_ref().unwrap(), cx).into()),
445 ));
446 }
447
448 /// Bind the given callback on the hover start and end events of this element. Note that the boolean
449 /// passed to the callback is true when the hover starts and false when it ends.
450 /// The imperative API equivalent to [`StatefulInteractiveElement::on_drag`]
451 ///
452 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
453 pub fn on_hover(&mut self, listener: impl Fn(&bool, &mut WindowContext) + 'static)
454 where
455 Self: Sized,
456 {
457 debug_assert!(
458 self.hover_listener.is_none(),
459 "calling on_hover more than once on the same element is not supported"
460 );
461 self.hover_listener = Some(Box::new(listener));
462 }
463
464 /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
465 /// The imperative API equivalent to [`InteractiveElement::tooltip`]
466 pub fn tooltip(&mut self, build_tooltip: impl Fn(&mut WindowContext) -> AnyView + 'static)
467 where
468 Self: Sized,
469 {
470 debug_assert!(
471 self.tooltip_builder.is_none(),
472 "calling tooltip more than once on the same element is not supported"
473 );
474 self.tooltip_builder = Some(Rc::new(build_tooltip));
475 }
476
477 /// Block the mouse from interacting with this element or any of its children
478 /// The imperative API equivalent to [`InteractiveElement::block_mouse`]
479 pub fn occlude_mouse(&mut self) {
480 self.occlude_mouse = true;
481 }
482}
483
484/// A trait for elements that want to use the standard GPUI event handlers that don't
485/// require any state.
486pub trait InteractiveElement: Sized {
487 /// Retrieve the interactivity state associated with this element
488 fn interactivity(&mut self) -> &mut Interactivity;
489
490 /// Assign this element to a group of elements that can be styled together
491 fn group(mut self, group: impl Into<SharedString>) -> Self {
492 self.interactivity().group = Some(group.into());
493 self
494 }
495
496 /// Assign this element an ID, so that it can be used with interactivity
497 fn id(mut self, id: impl Into<ElementId>) -> Stateful<Self> {
498 self.interactivity().element_id = Some(id.into());
499
500 Stateful { element: self }
501 }
502
503 /// Track the focus state of the given focus handle on this element.
504 /// If the focus handle is focused by the application, this element will
505 /// apply its focused styles.
506 fn track_focus(mut self, focus_handle: &FocusHandle) -> Focusable<Self> {
507 self.interactivity().focusable = true;
508 self.interactivity().tracked_focus_handle = Some(focus_handle.clone());
509 Focusable { element: self }
510 }
511
512 /// Set the keymap context for this element. This will be used to determine
513 /// which action to dispatch from the keymap.
514 fn key_context<C, E>(mut self, key_context: C) -> Self
515 where
516 C: TryInto<KeyContext, Error = E>,
517 E: Debug,
518 {
519 if let Some(key_context) = key_context.try_into().log_err() {
520 self.interactivity().key_context = Some(key_context);
521 }
522 self
523 }
524
525 /// Apply the given style to this element when the mouse hovers over it
526 fn hover(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self {
527 debug_assert!(
528 self.interactivity().hover_style.is_none(),
529 "hover style already set"
530 );
531 self.interactivity().hover_style = Some(Box::new(f(StyleRefinement::default())));
532 self
533 }
534
535 /// Apply the given style to this element when the mouse hovers over a group member
536 fn group_hover(
537 mut self,
538 group_name: impl Into<SharedString>,
539 f: impl FnOnce(StyleRefinement) -> StyleRefinement,
540 ) -> Self {
541 self.interactivity().group_hover_style = Some(GroupStyle {
542 group: group_name.into(),
543 style: Box::new(f(StyleRefinement::default())),
544 });
545 self
546 }
547
548 /// Bind the given callback to the mouse down event for the given mouse button,
549 /// the fluent API equivalent to [`Interactivity::on_mouse_down`]
550 ///
551 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to the view state from this callback.
552 fn on_mouse_down(
553 mut self,
554 button: MouseButton,
555 listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
556 ) -> Self {
557 self.interactivity().on_mouse_down(button, listener);
558 self
559 }
560
561 #[cfg(any(test, feature = "test-support"))]
562 /// Set a key that can be used to look up this element's bounds
563 /// in the [`VisualTestContext::debug_bounds`] map
564 /// This is a noop in release builds
565 fn debug_selector(mut self, f: impl FnOnce() -> String) -> Self {
566 self.interactivity().debug_selector = Some(f());
567 self
568 }
569
570 #[cfg(not(any(test, feature = "test-support")))]
571 /// Set a key that can be used to look up this element's bounds
572 /// in the [`VisualTestContext::debug_bounds`] map
573 /// This is a noop in release builds
574 #[inline]
575 fn debug_selector(self, _: impl FnOnce() -> String) -> Self {
576 self
577 }
578
579 /// Bind the given callback to the mouse down event for any button, during the capture phase
580 /// the fluent API equivalent to [`Interactivity::capture_any_mouse_down`]
581 ///
582 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
583 fn capture_any_mouse_down(
584 mut self,
585 listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
586 ) -> Self {
587 self.interactivity().capture_any_mouse_down(listener);
588 self
589 }
590
591 /// Bind the given callback to the mouse down event for any button, during the capture phase
592 /// the fluent API equivalent to [`Interactivity::on_any_mouse_down`]
593 ///
594 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
595 fn on_any_mouse_down(
596 mut self,
597 listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
598 ) -> Self {
599 self.interactivity().on_any_mouse_down(listener);
600 self
601 }
602
603 /// Bind the given callback to the mouse up event for the given button, during the bubble phase
604 /// the fluent API equivalent to [`Interactivity::on_mouse_up`]
605 ///
606 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
607 fn on_mouse_up(
608 mut self,
609 button: MouseButton,
610 listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
611 ) -> Self {
612 self.interactivity().on_mouse_up(button, listener);
613 self
614 }
615
616 /// Bind the given callback to the mouse up event for any button, during the capture phase
617 /// the fluent API equivalent to [`Interactivity::capture_any_mouse_up`]
618 ///
619 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
620 fn capture_any_mouse_up(
621 mut self,
622 listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
623 ) -> Self {
624 self.interactivity().capture_any_mouse_up(listener);
625 self
626 }
627
628 /// Bind the given callback to the mouse down event, on any button, during the capture phase,
629 /// when the mouse is outside of the bounds of this element.
630 /// The fluent API equivalent to [`Interactivity::on_mouse_down_out`]
631 ///
632 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
633 fn on_mouse_down_out(
634 mut self,
635 listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
636 ) -> Self {
637 self.interactivity().on_mouse_down_out(listener);
638 self
639 }
640
641 /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
642 /// when the mouse is outside of the bounds of this element.
643 /// The fluent API equivalent to [`Interactivity::on_mouse_up_out`]
644 ///
645 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
646 fn on_mouse_up_out(
647 mut self,
648 button: MouseButton,
649 listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
650 ) -> Self {
651 self.interactivity().on_mouse_up_out(button, listener);
652 self
653 }
654
655 /// Bind the given callback to the mouse move event, during the bubble phase
656 /// The fluent API equivalent to [`Interactivity::on_mouse_move`]
657 ///
658 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
659 fn on_mouse_move(
660 mut self,
661 listener: impl Fn(&MouseMoveEvent, &mut WindowContext) + 'static,
662 ) -> Self {
663 self.interactivity().on_mouse_move(listener);
664 self
665 }
666
667 /// Bind the given callback to the mouse drag event of the given type. Note that this
668 /// will be called for all move events, inside or outside of this element, as long as the
669 /// drag was started with this element under the mouse. Useful for implementing draggable
670 /// UIs that don't conform to a drag and drop style interaction, like resizing.
671 /// The fluent API equivalent to [`Interactivity::on_drag_move`]
672 ///
673 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
674 fn on_drag_move<T: 'static>(
675 mut self,
676 listener: impl Fn(&DragMoveEvent<T>, &mut WindowContext) + 'static,
677 ) -> Self
678 where
679 T: 'static,
680 {
681 self.interactivity().on_drag_move(listener);
682 self
683 }
684
685 /// Bind the given callback to scroll wheel events during the bubble phase
686 /// The fluent API equivalent to [`Interactivity::on_scroll_wheel`]
687 ///
688 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
689 fn on_scroll_wheel(
690 mut self,
691 listener: impl Fn(&ScrollWheelEvent, &mut WindowContext) + 'static,
692 ) -> Self {
693 self.interactivity().on_scroll_wheel(listener);
694 self
695 }
696
697 /// Capture the given action, before normal action dispatch can fire
698 /// The fluent API equivalent to [`Interactivity::on_scroll_wheel`]
699 ///
700 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
701 fn capture_action<A: Action>(
702 mut self,
703 listener: impl Fn(&A, &mut WindowContext) + 'static,
704 ) -> Self {
705 self.interactivity().capture_action(listener);
706 self
707 }
708
709 /// Bind the given callback to an action dispatch during the bubble phase
710 /// The fluent API equivalent to [`Interactivity::on_action`]
711 ///
712 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
713 fn on_action<A: Action>(mut self, listener: impl Fn(&A, &mut WindowContext) + 'static) -> Self {
714 self.interactivity().on_action(listener);
715 self
716 }
717
718 /// Bind the given callback to an action dispatch, based on a dynamic action parameter
719 /// instead of a type parameter. Useful for component libraries that want to expose
720 /// action bindings to their users.
721 /// The fluent API equivalent to [`Interactivity::on_boxed_action`]
722 ///
723 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
724 fn on_boxed_action(
725 mut self,
726 action: &dyn Action,
727 listener: impl Fn(&Box<dyn Action>, &mut WindowContext) + 'static,
728 ) -> Self {
729 self.interactivity().on_boxed_action(action, listener);
730 self
731 }
732
733 /// Bind the given callback to key down events during the bubble phase
734 /// The fluent API equivalent to [`Interactivity::on_key_down`]
735 ///
736 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
737 fn on_key_down(
738 mut self,
739 listener: impl Fn(&KeyDownEvent, &mut WindowContext) + 'static,
740 ) -> Self {
741 self.interactivity().on_key_down(listener);
742 self
743 }
744
745 /// Bind the given callback to key down events during the capture phase
746 /// The fluent API equivalent to [`Interactivity::capture_key_down`]
747 ///
748 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
749 fn capture_key_down(
750 mut self,
751 listener: impl Fn(&KeyDownEvent, &mut WindowContext) + 'static,
752 ) -> Self {
753 self.interactivity().capture_key_down(listener);
754 self
755 }
756
757 /// Bind the given callback to key up events during the bubble phase
758 /// The fluent API equivalent to [`Interactivity::on_key_up`]
759 ///
760 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
761 fn on_key_up(mut self, listener: impl Fn(&KeyUpEvent, &mut WindowContext) + 'static) -> Self {
762 self.interactivity().on_key_up(listener);
763 self
764 }
765
766 /// Bind the given callback to key up events during the capture phase
767 /// The fluent API equivalent to [`Interactivity::capture_key_up`]
768 ///
769 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
770 fn capture_key_up(
771 mut self,
772 listener: impl Fn(&KeyUpEvent, &mut WindowContext) + 'static,
773 ) -> Self {
774 self.interactivity().capture_key_up(listener);
775 self
776 }
777
778 /// Apply the given style when the given data type is dragged over this element
779 fn drag_over<S: 'static>(
780 mut self,
781 f: impl 'static + Fn(StyleRefinement, &S, &WindowContext) -> StyleRefinement,
782 ) -> Self {
783 self.interactivity().drag_over_styles.push((
784 TypeId::of::<S>(),
785 Box::new(move |currently_dragged: &dyn Any, cx| {
786 f(
787 StyleRefinement::default(),
788 currently_dragged.downcast_ref::<S>().unwrap(),
789 cx,
790 )
791 }),
792 ));
793 self
794 }
795
796 /// Apply the given style when the given data type is dragged over this element's group
797 fn group_drag_over<S: 'static>(
798 mut self,
799 group_name: impl Into<SharedString>,
800 f: impl FnOnce(StyleRefinement) -> StyleRefinement,
801 ) -> Self {
802 self.interactivity().group_drag_over_styles.push((
803 TypeId::of::<S>(),
804 GroupStyle {
805 group: group_name.into(),
806 style: Box::new(f(StyleRefinement::default())),
807 },
808 ));
809 self
810 }
811
812 /// Bind the given callback to drop events of the given type, whether or not the drag started on this element
813 /// The fluent API equivalent to [`Interactivity::on_drop`]
814 ///
815 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
816 fn on_drop<T: 'static>(mut self, listener: impl Fn(&T, &mut WindowContext) + 'static) -> Self {
817 self.interactivity().on_drop(listener);
818 self
819 }
820
821 /// Use the given predicate to determine whether or not a drop event should be dispatched to this element
822 /// The fluent API equivalent to [`Interactivity::can_drop`]
823 fn can_drop(
824 mut self,
825 predicate: impl Fn(&dyn Any, &mut WindowContext) -> bool + 'static,
826 ) -> Self {
827 self.interactivity().can_drop(predicate);
828 self
829 }
830
831 /// Block the mouse from interacting with this element or any of its children
832 /// The fluent API equivalent to [`Interactivity::block_mouse`]
833 fn occlude(mut self) -> Self {
834 self.interactivity().occlude_mouse();
835 self
836 }
837}
838
839/// A trait for elements that want to use the standard GPUI interactivity features
840/// that require state.
841pub trait StatefulInteractiveElement: InteractiveElement {
842 /// Set this element to focusable.
843 fn focusable(mut self) -> Focusable<Self> {
844 self.interactivity().focusable = true;
845 Focusable { element: self }
846 }
847
848 /// Set the overflow x and y to scroll.
849 fn overflow_scroll(mut self) -> Self {
850 self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
851 self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
852 self
853 }
854
855 /// Set the overflow x to scroll.
856 fn overflow_x_scroll(mut self) -> Self {
857 self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
858 self
859 }
860
861 /// Set the overflow y to scroll.
862 fn overflow_y_scroll(mut self) -> Self {
863 self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
864 self
865 }
866
867 /// Track the scroll state of this element with the given handle.
868 fn track_scroll(mut self, scroll_handle: &ScrollHandle) -> Self {
869 self.interactivity().tracked_scroll_handle = Some(scroll_handle.clone());
870 self
871 }
872
873 /// Set the given styles to be applied when this element is active.
874 fn active(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
875 where
876 Self: Sized,
877 {
878 self.interactivity().active_style = Some(Box::new(f(StyleRefinement::default())));
879 self
880 }
881
882 /// Set the given styles to be applied when this element's group is active.
883 fn group_active(
884 mut self,
885 group_name: impl Into<SharedString>,
886 f: impl FnOnce(StyleRefinement) -> StyleRefinement,
887 ) -> Self
888 where
889 Self: Sized,
890 {
891 self.interactivity().group_active_style = Some(GroupStyle {
892 group: group_name.into(),
893 style: Box::new(f(StyleRefinement::default())),
894 });
895 self
896 }
897
898 /// Bind the given callback to click events of this element
899 /// The fluent API equivalent to [`Interactivity::on_click`]
900 ///
901 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
902 fn on_click(mut self, listener: impl Fn(&ClickEvent, &mut WindowContext) + 'static) -> Self
903 where
904 Self: Sized,
905 {
906 self.interactivity().on_click(listener);
907 self
908 }
909
910 /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
911 /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
912 /// the [`Self::on_drag_move`] API
913 /// The fluent API equivalent to [`Interactivity::on_drag`]
914 ///
915 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
916 fn on_drag<T, W>(
917 mut self,
918 value: T,
919 constructor: impl Fn(&T, &mut WindowContext) -> View<W> + 'static,
920 ) -> Self
921 where
922 Self: Sized,
923 T: 'static,
924 W: 'static + Render,
925 {
926 self.interactivity().on_drag(value, constructor);
927 self
928 }
929
930 /// Bind the given callback on the hover start and end events of this element. Note that the boolean
931 /// passed to the callback is true when the hover starts and false when it ends.
932 /// The fluent API equivalent to [`Interactivity::on_hover`]
933 ///
934 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
935 fn on_hover(mut self, listener: impl Fn(&bool, &mut WindowContext) + 'static) -> Self
936 where
937 Self: Sized,
938 {
939 self.interactivity().on_hover(listener);
940 self
941 }
942
943 /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
944 /// The fluent API equivalent to [`Interactivity::tooltip`]
945 fn tooltip(mut self, build_tooltip: impl Fn(&mut WindowContext) -> AnyView + 'static) -> Self
946 where
947 Self: Sized,
948 {
949 self.interactivity().tooltip(build_tooltip);
950 self
951 }
952}
953
954/// A trait for providing focus related APIs to interactive elements
955pub trait FocusableElement: InteractiveElement {
956 /// Set the given styles to be applied when this element, specifically, is focused.
957 fn focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
958 where
959 Self: Sized,
960 {
961 self.interactivity().focus_style = Some(Box::new(f(StyleRefinement::default())));
962 self
963 }
964
965 /// Set the given styles to be applied when this element is inside another element that is focused.
966 fn in_focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
967 where
968 Self: Sized,
969 {
970 self.interactivity().in_focus_style = Some(Box::new(f(StyleRefinement::default())));
971 self
972 }
973}
974
975pub(crate) type MouseDownListener =
976 Box<dyn Fn(&MouseDownEvent, DispatchPhase, &Hitbox, &mut WindowContext) + 'static>;
977pub(crate) type MouseUpListener =
978 Box<dyn Fn(&MouseUpEvent, DispatchPhase, &Hitbox, &mut WindowContext) + 'static>;
979
980pub(crate) type MouseMoveListener =
981 Box<dyn Fn(&MouseMoveEvent, DispatchPhase, &Hitbox, &mut WindowContext) + 'static>;
982
983pub(crate) type ScrollWheelListener =
984 Box<dyn Fn(&ScrollWheelEvent, DispatchPhase, &Hitbox, &mut WindowContext) + 'static>;
985
986pub(crate) type ClickListener = Box<dyn Fn(&ClickEvent, &mut WindowContext) + 'static>;
987
988pub(crate) type DragListener = Box<dyn Fn(&dyn Any, &mut WindowContext) -> AnyView + 'static>;
989
990type DropListener = Box<dyn Fn(&dyn Any, &mut WindowContext) + 'static>;
991
992type CanDropPredicate = Box<dyn Fn(&dyn Any, &mut WindowContext) -> bool + 'static>;
993
994pub(crate) type TooltipBuilder = Rc<dyn Fn(&mut WindowContext) -> AnyView + 'static>;
995
996pub(crate) type KeyDownListener =
997 Box<dyn Fn(&KeyDownEvent, DispatchPhase, &mut WindowContext) + 'static>;
998
999pub(crate) type KeyUpListener =
1000 Box<dyn Fn(&KeyUpEvent, DispatchPhase, &mut WindowContext) + 'static>;
1001
1002pub(crate) type ActionListener = Box<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
1003
1004/// Construct a new [`Div`] element
1005#[track_caller]
1006pub fn div() -> Div {
1007 #[cfg(debug_assertions)]
1008 let interactivity = Interactivity {
1009 location: Some(*core::panic::Location::caller()),
1010 ..Default::default()
1011 };
1012
1013 #[cfg(not(debug_assertions))]
1014 let interactivity = Interactivity::default();
1015
1016 Div {
1017 interactivity,
1018 children: SmallVec::default(),
1019 }
1020}
1021
1022/// A [`Div`] element, the all-in-one element for building complex UIs in GPUI
1023pub struct Div {
1024 interactivity: Interactivity,
1025 children: SmallVec<[AnyElement; 2]>,
1026}
1027
1028/// A frame state for a `Div` element, which contains layout IDs for its children.
1029///
1030/// This struct is used internally by the `Div` element to manage the layout state of its children
1031/// during the UI update cycle. It holds a small vector of `LayoutId` values, each corresponding to
1032/// a child element of the `Div`. These IDs are used to query the layout engine for the computed
1033/// bounds of the children after the layout phase is complete.
1034pub struct DivFrameState {
1035 child_layout_ids: SmallVec<[LayoutId; 2]>,
1036}
1037
1038impl Styled for Div {
1039 fn style(&mut self) -> &mut StyleRefinement {
1040 &mut self.interactivity.base_style
1041 }
1042}
1043
1044impl InteractiveElement for Div {
1045 fn interactivity(&mut self) -> &mut Interactivity {
1046 &mut self.interactivity
1047 }
1048}
1049
1050impl ParentElement for Div {
1051 fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
1052 self.children.extend(elements)
1053 }
1054}
1055
1056impl Element for Div {
1057 type BeforeLayout = DivFrameState;
1058 type AfterLayout = Option<Hitbox>;
1059
1060 fn before_layout(&mut self, cx: &mut ElementContext) -> (LayoutId, Self::BeforeLayout) {
1061 let mut child_layout_ids = SmallVec::new();
1062 let layout_id = self.interactivity.before_layout(cx, |style, cx| {
1063 cx.with_text_style(style.text_style().cloned(), |cx| {
1064 child_layout_ids = self
1065 .children
1066 .iter_mut()
1067 .map(|child| child.before_layout(cx))
1068 .collect::<SmallVec<_>>();
1069 cx.request_layout(&style, child_layout_ids.iter().copied())
1070 })
1071 });
1072 (layout_id, DivFrameState { child_layout_ids })
1073 }
1074
1075 fn after_layout(
1076 &mut self,
1077 bounds: Bounds<Pixels>,
1078 before_layout: &mut Self::BeforeLayout,
1079 cx: &mut ElementContext,
1080 ) -> Option<Hitbox> {
1081 let mut child_min = point(Pixels::MAX, Pixels::MAX);
1082 let mut child_max = Point::default();
1083 let content_size = if before_layout.child_layout_ids.is_empty() {
1084 bounds.size
1085 } else if let Some(scroll_handle) = self.interactivity.tracked_scroll_handle.as_ref() {
1086 let mut state = scroll_handle.0.borrow_mut();
1087 state.child_bounds = Vec::with_capacity(before_layout.child_layout_ids.len());
1088 state.bounds = bounds;
1089 let requested = state.requested_scroll_top.take();
1090
1091 for (ix, child_layout_id) in before_layout.child_layout_ids.iter().enumerate() {
1092 let child_bounds = cx.layout_bounds(*child_layout_id);
1093 child_min = child_min.min(&child_bounds.origin);
1094 child_max = child_max.max(&child_bounds.lower_right());
1095 state.child_bounds.push(child_bounds);
1096
1097 if let Some(requested) = requested.as_ref() {
1098 if requested.0 == ix {
1099 *state.offset.borrow_mut() =
1100 bounds.origin - (child_bounds.origin - point(px(0.), requested.1));
1101 }
1102 }
1103 }
1104 (child_max - child_min).into()
1105 } else {
1106 for child_layout_id in &before_layout.child_layout_ids {
1107 let child_bounds = cx.layout_bounds(*child_layout_id);
1108 child_min = child_min.min(&child_bounds.origin);
1109 child_max = child_max.max(&child_bounds.lower_right());
1110 }
1111 (child_max - child_min).into()
1112 };
1113
1114 self.interactivity.after_layout(
1115 bounds,
1116 content_size,
1117 cx,
1118 |_style, scroll_offset, hitbox, cx| {
1119 cx.with_element_offset(scroll_offset, |cx| {
1120 for child in &mut self.children {
1121 child.after_layout(cx);
1122 }
1123 });
1124 hitbox
1125 },
1126 )
1127 }
1128
1129 fn paint(
1130 &mut self,
1131 bounds: Bounds<Pixels>,
1132 _before_layout: &mut Self::BeforeLayout,
1133 hitbox: &mut Option<Hitbox>,
1134 cx: &mut ElementContext,
1135 ) {
1136 self.interactivity
1137 .paint(bounds, hitbox.as_ref(), cx, |_style, cx| {
1138 for child in &mut self.children {
1139 child.paint(cx);
1140 }
1141 });
1142 }
1143}
1144
1145impl IntoElement for Div {
1146 type Element = Self;
1147
1148 fn into_element(self) -> Self::Element {
1149 self
1150 }
1151}
1152
1153/// The interactivity struct. Powers all of the general-purpose
1154/// interactivity in the `Div` element.
1155#[derive(Default)]
1156pub struct Interactivity {
1157 /// The element ID of the element
1158 pub element_id: Option<ElementId>,
1159 /// Whether the element was clicked. This will only be present after layout.
1160 pub active: Option<bool>,
1161 /// Whether the element was hovered. This will only be present after paint if an hitbox
1162 /// was created for the interactive element.
1163 pub hovered: Option<bool>,
1164 pub(crate) content_size: Size<Pixels>,
1165 pub(crate) key_context: Option<KeyContext>,
1166 pub(crate) focusable: bool,
1167 pub(crate) tracked_focus_handle: Option<FocusHandle>,
1168 pub(crate) tracked_scroll_handle: Option<ScrollHandle>,
1169 pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
1170 pub(crate) group: Option<SharedString>,
1171 /// The base style of the element, before any modifications are applied
1172 /// by focus, active, etc.
1173 pub base_style: Box<StyleRefinement>,
1174 pub(crate) focus_style: Option<Box<StyleRefinement>>,
1175 pub(crate) in_focus_style: Option<Box<StyleRefinement>>,
1176 pub(crate) hover_style: Option<Box<StyleRefinement>>,
1177 pub(crate) group_hover_style: Option<GroupStyle>,
1178 pub(crate) active_style: Option<Box<StyleRefinement>>,
1179 pub(crate) group_active_style: Option<GroupStyle>,
1180 pub(crate) drag_over_styles: Vec<(
1181 TypeId,
1182 Box<dyn Fn(&dyn Any, &mut WindowContext) -> StyleRefinement>,
1183 )>,
1184 pub(crate) group_drag_over_styles: Vec<(TypeId, GroupStyle)>,
1185 pub(crate) mouse_down_listeners: Vec<MouseDownListener>,
1186 pub(crate) mouse_up_listeners: Vec<MouseUpListener>,
1187 pub(crate) mouse_move_listeners: Vec<MouseMoveListener>,
1188 pub(crate) scroll_wheel_listeners: Vec<ScrollWheelListener>,
1189 pub(crate) key_down_listeners: Vec<KeyDownListener>,
1190 pub(crate) key_up_listeners: Vec<KeyUpListener>,
1191 pub(crate) action_listeners: Vec<(TypeId, ActionListener)>,
1192 pub(crate) drop_listeners: Vec<(TypeId, DropListener)>,
1193 pub(crate) can_drop_predicate: Option<CanDropPredicate>,
1194 pub(crate) click_listeners: Vec<ClickListener>,
1195 pub(crate) drag_listener: Option<(Box<dyn Any>, DragListener)>,
1196 pub(crate) hover_listener: Option<Box<dyn Fn(&bool, &mut WindowContext)>>,
1197 pub(crate) tooltip_builder: Option<TooltipBuilder>,
1198 pub(crate) occlude_mouse: bool,
1199
1200 #[cfg(debug_assertions)]
1201 pub(crate) location: Option<core::panic::Location<'static>>,
1202
1203 #[cfg(any(test, feature = "test-support"))]
1204 pub(crate) debug_selector: Option<String>,
1205}
1206
1207impl Interactivity {
1208 /// Layout this element according to this interactivity state's configured styles
1209 pub fn before_layout(
1210 &mut self,
1211 cx: &mut ElementContext,
1212 f: impl FnOnce(Style, &mut ElementContext) -> LayoutId,
1213 ) -> LayoutId {
1214 cx.with_element_state::<InteractiveElementState, _>(
1215 self.element_id.clone(),
1216 |element_state, cx| {
1217 let mut element_state =
1218 element_state.map(|element_state| element_state.unwrap_or_default());
1219
1220 if let Some(element_state) = element_state.as_ref() {
1221 if cx.has_active_drag() {
1222 if let Some(pending_mouse_down) = element_state.pending_mouse_down.as_ref()
1223 {
1224 *pending_mouse_down.borrow_mut() = None;
1225 }
1226 if let Some(clicked_state) = element_state.clicked_state.as_ref() {
1227 *clicked_state.borrow_mut() = ElementClickedState::default();
1228 }
1229 }
1230 }
1231
1232 // Ensure we store a focus handle in our element state if we're focusable.
1233 // If there's an explicit focus handle we're tracking, use that. Otherwise
1234 // create a new handle and store it in the element state, which lives for as
1235 // as frames contain an element with this id.
1236 if self.focusable {
1237 if self.tracked_focus_handle.is_none() {
1238 if let Some(element_state) = element_state.as_mut() {
1239 self.tracked_focus_handle = Some(
1240 element_state
1241 .focus_handle
1242 .get_or_insert_with(|| cx.focus_handle())
1243 .clone(),
1244 );
1245 }
1246 }
1247 }
1248
1249 if let Some(scroll_handle) = self.tracked_scroll_handle.as_ref() {
1250 self.scroll_offset = Some(scroll_handle.0.borrow().offset.clone());
1251 } else if self.base_style.overflow.x == Some(Overflow::Scroll)
1252 || self.base_style.overflow.y == Some(Overflow::Scroll)
1253 {
1254 if let Some(element_state) = element_state.as_mut() {
1255 self.scroll_offset = Some(
1256 element_state
1257 .scroll_offset
1258 .get_or_insert_with(|| Rc::default())
1259 .clone(),
1260 );
1261 }
1262 }
1263
1264 let style = self.compute_style_internal(None, element_state.as_mut(), cx);
1265 let layout_id = f(style, cx);
1266 (layout_id, element_state)
1267 },
1268 )
1269 }
1270
1271 /// Commit the bounds of this element according to this interactivity state's configured styles.
1272 pub fn after_layout<R>(
1273 &mut self,
1274 bounds: Bounds<Pixels>,
1275 content_size: Size<Pixels>,
1276 cx: &mut ElementContext,
1277 f: impl FnOnce(&Style, Point<Pixels>, Option<Hitbox>, &mut ElementContext) -> R,
1278 ) -> R {
1279 self.content_size = content_size;
1280 cx.with_element_state::<InteractiveElementState, _>(
1281 self.element_id.clone(),
1282 |element_state, cx| {
1283 let mut element_state =
1284 element_state.map(|element_state| element_state.unwrap_or_default());
1285 let style = self.compute_style_internal(None, element_state.as_mut(), cx);
1286
1287 if let Some(element_state) = element_state.as_ref() {
1288 if let Some(clicked_state) = element_state.clicked_state.as_ref() {
1289 let clicked_state = clicked_state.borrow();
1290 self.active = Some(clicked_state.element);
1291 }
1292
1293 if let Some(active_tooltip) = element_state.active_tooltip.as_ref() {
1294 if let Some(active_tooltip) = active_tooltip.borrow().as_ref() {
1295 if let Some(tooltip) = active_tooltip.tooltip.clone() {
1296 cx.set_tooltip(tooltip);
1297 }
1298 }
1299 }
1300 }
1301
1302 cx.with_text_style(style.text_style().cloned(), |cx| {
1303 cx.with_content_mask(style.overflow_mask(bounds, cx.rem_size()), |cx| {
1304 let hitbox = if self.should_insert_hitbox(&style) {
1305 Some(cx.insert_hitbox(bounds, self.occlude_mouse))
1306 } else {
1307 None
1308 };
1309
1310 let scroll_offset = self.clamp_scroll_position(bounds, &style, cx);
1311 let result = f(&style, scroll_offset, hitbox, cx);
1312 (result, element_state)
1313 })
1314 })
1315 },
1316 )
1317 }
1318
1319 fn should_insert_hitbox(&self, style: &Style) -> bool {
1320 self.occlude_mouse
1321 || style.mouse_cursor.is_some()
1322 || self.group.is_some()
1323 || self.scroll_offset.is_some()
1324 || self.tracked_focus_handle.is_some()
1325 || self.hover_style.is_some()
1326 || self.group_hover_style.is_some()
1327 || !self.mouse_up_listeners.is_empty()
1328 || !self.mouse_down_listeners.is_empty()
1329 || !self.mouse_move_listeners.is_empty()
1330 || !self.click_listeners.is_empty()
1331 || !self.scroll_wheel_listeners.is_empty()
1332 || self.drag_listener.is_some()
1333 || !self.drop_listeners.is_empty()
1334 || self.tooltip_builder.is_some()
1335 }
1336
1337 fn clamp_scroll_position(
1338 &mut self,
1339 bounds: Bounds<Pixels>,
1340 style: &Style,
1341 cx: &mut ElementContext,
1342 ) -> Point<Pixels> {
1343 if let Some(scroll_offset) = self.scroll_offset.as_ref() {
1344 if let Some(scroll_handle) = &self.tracked_scroll_handle {
1345 scroll_handle.0.borrow_mut().overflow = style.overflow;
1346 }
1347
1348 let rem_size = cx.rem_size();
1349 let padding_size = size(
1350 style
1351 .padding
1352 .left
1353 .to_pixels(bounds.size.width.into(), rem_size)
1354 + style
1355 .padding
1356 .right
1357 .to_pixels(bounds.size.width.into(), rem_size),
1358 style
1359 .padding
1360 .top
1361 .to_pixels(bounds.size.height.into(), rem_size)
1362 + style
1363 .padding
1364 .bottom
1365 .to_pixels(bounds.size.height.into(), rem_size),
1366 );
1367 let scroll_max = (self.content_size + padding_size - bounds.size).max(&Size::default());
1368 // Clamp scroll offset in case scroll max is smaller now (e.g., if children
1369 // were removed or the bounds became larger).
1370 let mut scroll_offset = scroll_offset.borrow_mut();
1371 scroll_offset.x = scroll_offset.x.clamp(-scroll_max.width, px(0.));
1372 scroll_offset.y = scroll_offset.y.clamp(-scroll_max.height, px(0.));
1373 *scroll_offset
1374 } else {
1375 Point::default()
1376 }
1377 }
1378
1379 /// Paint this element according to this interactivity state's configured styles
1380 /// and bind the element's mouse and keyboard events.
1381 ///
1382 /// content_size is the size of the content of the element, which may be larger than the
1383 /// element's bounds if the element is scrollable.
1384 ///
1385 /// the final computed style will be passed to the provided function, along
1386 /// with the current scroll offset
1387 pub fn paint(
1388 &mut self,
1389 bounds: Bounds<Pixels>,
1390 hitbox: Option<&Hitbox>,
1391 cx: &mut ElementContext,
1392 f: impl FnOnce(&Style, &mut ElementContext),
1393 ) {
1394 self.hovered = hitbox.map(|hitbox| hitbox.is_hovered(cx));
1395 cx.with_element_state::<InteractiveElementState, _>(
1396 self.element_id.clone(),
1397 |element_state, cx| {
1398 let mut element_state =
1399 element_state.map(|element_state| element_state.unwrap_or_default());
1400
1401 let style = self.compute_style_internal(hitbox, element_state.as_mut(), cx);
1402
1403 #[cfg(any(feature = "test-support", test))]
1404 if let Some(debug_selector) = &self.debug_selector {
1405 cx.window
1406 .next_frame
1407 .debug_bounds
1408 .insert(debug_selector.clone(), bounds);
1409 }
1410
1411 self.paint_hover_group_handler(cx);
1412
1413 if style.visibility == Visibility::Hidden {
1414 return ((), element_state);
1415 }
1416
1417 style.paint(bounds, cx, |cx: &mut ElementContext| {
1418 cx.with_text_style(style.text_style().cloned(), |cx| {
1419 cx.with_content_mask(style.overflow_mask(bounds, cx.rem_size()), |cx| {
1420 if let Some(hitbox) = hitbox {
1421 #[cfg(debug_assertions)]
1422 self.paint_debug_info(hitbox, &style, cx);
1423
1424 if !cx.has_active_drag() {
1425 if let Some(mouse_cursor) = style.mouse_cursor {
1426 cx.set_cursor_style(mouse_cursor, hitbox);
1427 }
1428 }
1429
1430 if let Some(group) = self.group.clone() {
1431 GroupHitboxes::push(group, hitbox.id, cx);
1432 }
1433
1434 self.paint_mouse_listeners(hitbox, element_state.as_mut(), cx);
1435 self.paint_scroll_listener(hitbox, &style, cx);
1436 }
1437
1438 self.paint_keyboard_listeners(cx);
1439 f(&style, cx);
1440
1441 if hitbox.is_some() {
1442 if let Some(group) = self.group.as_ref() {
1443 GroupHitboxes::pop(group, cx);
1444 }
1445 }
1446 });
1447 });
1448 });
1449
1450 ((), element_state)
1451 },
1452 );
1453 }
1454
1455 #[cfg(debug_assertions)]
1456 fn paint_debug_info(&mut self, hitbox: &Hitbox, style: &Style, cx: &mut ElementContext) {
1457 if self.element_id.is_some()
1458 && (style.debug || style.debug_below || cx.has_global::<crate::DebugBelow>())
1459 && hitbox.is_hovered(cx)
1460 {
1461 const FONT_SIZE: crate::Pixels = crate::Pixels(10.);
1462 let element_id = format!("{:?}", self.element_id.as_ref().unwrap());
1463 let str_len = element_id.len();
1464
1465 let render_debug_text = |cx: &mut ElementContext| {
1466 if let Some(text) = cx
1467 .text_system()
1468 .shape_text(
1469 element_id.into(),
1470 FONT_SIZE,
1471 &[cx.text_style().to_run(str_len)],
1472 None,
1473 )
1474 .ok()
1475 .and_then(|mut text| text.pop())
1476 {
1477 text.paint(hitbox.origin, FONT_SIZE, cx).ok();
1478
1479 let text_bounds = crate::Bounds {
1480 origin: hitbox.origin,
1481 size: text.size(FONT_SIZE),
1482 };
1483 if self.location.is_some()
1484 && text_bounds.contains(&cx.mouse_position())
1485 && cx.modifiers().command
1486 {
1487 let command_held = cx.modifiers().command;
1488 cx.on_key_event({
1489 move |e: &crate::ModifiersChangedEvent, _phase, cx| {
1490 if e.modifiers.command != command_held
1491 && text_bounds.contains(&cx.mouse_position())
1492 {
1493 cx.refresh();
1494 }
1495 }
1496 });
1497
1498 let was_hovered = hitbox.is_hovered(cx);
1499 cx.on_mouse_event({
1500 let hitbox = hitbox.clone();
1501 move |_: &MouseMoveEvent, phase, cx| {
1502 if phase == DispatchPhase::Capture {
1503 let hovered = hitbox.is_hovered(cx);
1504 if hovered != was_hovered {
1505 cx.refresh();
1506 }
1507 }
1508 }
1509 });
1510
1511 cx.on_mouse_event({
1512 let hitbox = hitbox.clone();
1513 let location = self.location.unwrap();
1514 move |e: &crate::MouseDownEvent, phase, cx| {
1515 if text_bounds.contains(&e.position)
1516 && phase.capture()
1517 && hitbox.is_hovered(cx)
1518 {
1519 cx.stop_propagation();
1520 let Ok(dir) = std::env::current_dir() else {
1521 return;
1522 };
1523
1524 eprintln!(
1525 "This element was created at:\n{}:{}:{}",
1526 dir.join(location.file()).to_string_lossy(),
1527 location.line(),
1528 location.column()
1529 );
1530 }
1531 }
1532 });
1533 cx.paint_quad(crate::outline(
1534 crate::Bounds {
1535 origin: hitbox.origin
1536 + crate::point(crate::px(0.), FONT_SIZE - px(2.)),
1537 size: crate::Size {
1538 width: text_bounds.size.width,
1539 height: crate::px(1.),
1540 },
1541 },
1542 crate::red(),
1543 ))
1544 }
1545 }
1546 };
1547
1548 cx.with_text_style(
1549 Some(crate::TextStyleRefinement {
1550 color: Some(crate::red()),
1551 line_height: Some(FONT_SIZE.into()),
1552 background_color: Some(crate::white()),
1553 ..Default::default()
1554 }),
1555 render_debug_text,
1556 )
1557 }
1558 }
1559
1560 fn paint_mouse_listeners(
1561 &mut self,
1562 hitbox: &Hitbox,
1563 element_state: Option<&mut InteractiveElementState>,
1564 cx: &mut ElementContext,
1565 ) {
1566 // If this element can be focused, register a mouse down listener
1567 // that will automatically transfer focus when hitting the element.
1568 // This behavior can be suppressed by using `cx.prevent_default()`.
1569 if let Some(focus_handle) = self.tracked_focus_handle.clone() {
1570 let hitbox = hitbox.clone();
1571 cx.on_mouse_event(move |_: &MouseDownEvent, phase, cx| {
1572 if phase == DispatchPhase::Bubble
1573 && hitbox.is_hovered(cx)
1574 && !cx.default_prevented()
1575 {
1576 cx.focus(&focus_handle);
1577 // If there is a parent that is also focusable, prevent it
1578 // from transferring focus because we already did so.
1579 cx.prevent_default();
1580 }
1581 });
1582 }
1583
1584 for listener in self.mouse_down_listeners.drain(..) {
1585 let hitbox = hitbox.clone();
1586 cx.on_mouse_event(move |event: &MouseDownEvent, phase, cx| {
1587 listener(event, phase, &hitbox, cx);
1588 })
1589 }
1590
1591 for listener in self.mouse_up_listeners.drain(..) {
1592 let hitbox = hitbox.clone();
1593 cx.on_mouse_event(move |event: &MouseUpEvent, phase, cx| {
1594 listener(event, phase, &hitbox, cx);
1595 })
1596 }
1597
1598 for listener in self.mouse_move_listeners.drain(..) {
1599 let hitbox = hitbox.clone();
1600 cx.on_mouse_event(move |event: &MouseMoveEvent, phase, cx| {
1601 listener(event, phase, &hitbox, cx);
1602 })
1603 }
1604
1605 for listener in self.scroll_wheel_listeners.drain(..) {
1606 let hitbox = hitbox.clone();
1607 cx.on_mouse_event(move |event: &ScrollWheelEvent, phase, cx| {
1608 listener(event, phase, &hitbox, cx);
1609 })
1610 }
1611
1612 if self.hover_style.is_some()
1613 || self.base_style.mouse_cursor.is_some()
1614 || cx.active_drag.is_some() && !self.drag_over_styles.is_empty()
1615 {
1616 let hitbox = hitbox.clone();
1617 let was_hovered = hitbox.is_hovered(cx);
1618 cx.on_mouse_event(move |_: &MouseMoveEvent, phase, cx| {
1619 let hovered = hitbox.is_hovered(cx);
1620 if phase == DispatchPhase::Capture && hovered != was_hovered {
1621 cx.refresh();
1622 }
1623 });
1624 }
1625
1626 let mut drag_listener = mem::take(&mut self.drag_listener);
1627 let drop_listeners = mem::take(&mut self.drop_listeners);
1628 let click_listeners = mem::take(&mut self.click_listeners);
1629 let can_drop_predicate = mem::take(&mut self.can_drop_predicate);
1630
1631 if !drop_listeners.is_empty() {
1632 let hitbox = hitbox.clone();
1633 cx.on_mouse_event({
1634 move |_: &MouseUpEvent, phase, cx| {
1635 if let Some(drag) = &cx.active_drag {
1636 if phase == DispatchPhase::Bubble && hitbox.is_hovered(cx) {
1637 let drag_state_type = drag.value.as_ref().type_id();
1638 for (drop_state_type, listener) in &drop_listeners {
1639 if *drop_state_type == drag_state_type {
1640 let drag = cx
1641 .active_drag
1642 .take()
1643 .expect("checked for type drag state type above");
1644
1645 let mut can_drop = true;
1646 if let Some(predicate) = &can_drop_predicate {
1647 can_drop = predicate(drag.value.as_ref(), cx.deref_mut());
1648 }
1649
1650 if can_drop {
1651 listener(drag.value.as_ref(), cx.deref_mut());
1652 cx.refresh();
1653 cx.stop_propagation();
1654 }
1655 }
1656 }
1657 }
1658 }
1659 }
1660 });
1661 }
1662
1663 if let Some(element_state) = element_state {
1664 if !click_listeners.is_empty() || drag_listener.is_some() {
1665 let pending_mouse_down = element_state
1666 .pending_mouse_down
1667 .get_or_insert_with(Default::default)
1668 .clone();
1669
1670 let clicked_state = element_state
1671 .clicked_state
1672 .get_or_insert_with(Default::default)
1673 .clone();
1674
1675 cx.on_mouse_event({
1676 let pending_mouse_down = pending_mouse_down.clone();
1677 let hitbox = hitbox.clone();
1678 move |event: &MouseDownEvent, phase, cx| {
1679 if phase == DispatchPhase::Bubble
1680 && event.button == MouseButton::Left
1681 && hitbox.is_hovered(cx)
1682 {
1683 *pending_mouse_down.borrow_mut() = Some(event.clone());
1684 cx.refresh();
1685 }
1686 }
1687 });
1688
1689 cx.on_mouse_event({
1690 let pending_mouse_down = pending_mouse_down.clone();
1691 let hitbox = hitbox.clone();
1692 move |event: &MouseMoveEvent, phase, cx| {
1693 if phase == DispatchPhase::Capture {
1694 return;
1695 }
1696
1697 let mut pending_mouse_down = pending_mouse_down.borrow_mut();
1698 if let Some(mouse_down) = pending_mouse_down.clone() {
1699 if !cx.has_active_drag()
1700 && (event.position - mouse_down.position).magnitude()
1701 > DRAG_THRESHOLD
1702 {
1703 if let Some((drag_value, drag_listener)) = drag_listener.take() {
1704 *clicked_state.borrow_mut() = ElementClickedState::default();
1705 let cursor_offset = event.position - hitbox.origin;
1706 let drag = (drag_listener)(drag_value.as_ref(), cx);
1707 cx.active_drag = Some(AnyDrag {
1708 view: drag,
1709 value: drag_value,
1710 cursor_offset,
1711 });
1712 pending_mouse_down.take();
1713 cx.refresh();
1714 cx.stop_propagation();
1715 }
1716 }
1717 }
1718 }
1719 });
1720
1721 cx.on_mouse_event({
1722 let mut captured_mouse_down = None;
1723 let hitbox = hitbox.clone();
1724 move |event: &MouseUpEvent, phase, cx| match phase {
1725 // Clear the pending mouse down during the capture phase,
1726 // so that it happens even if another event handler stops
1727 // propagation.
1728 DispatchPhase::Capture => {
1729 let mut pending_mouse_down = pending_mouse_down.borrow_mut();
1730 if pending_mouse_down.is_some() && hitbox.is_hovered(cx) {
1731 captured_mouse_down = pending_mouse_down.take();
1732 cx.refresh();
1733 }
1734 }
1735 // Fire click handlers during the bubble phase.
1736 DispatchPhase::Bubble => {
1737 if let Some(mouse_down) = captured_mouse_down.take() {
1738 let mouse_click = ClickEvent {
1739 down: mouse_down,
1740 up: event.clone(),
1741 };
1742 for listener in &click_listeners {
1743 listener(&mouse_click, cx);
1744 }
1745 }
1746 }
1747 }
1748 });
1749 }
1750
1751 if let Some(hover_listener) = self.hover_listener.take() {
1752 let hitbox = hitbox.clone();
1753 let was_hovered = element_state
1754 .hover_state
1755 .get_or_insert_with(Default::default)
1756 .clone();
1757 let has_mouse_down = element_state
1758 .pending_mouse_down
1759 .get_or_insert_with(Default::default)
1760 .clone();
1761
1762 cx.on_mouse_event(move |_: &MouseMoveEvent, phase, cx| {
1763 if phase != DispatchPhase::Bubble {
1764 return;
1765 }
1766 let is_hovered = has_mouse_down.borrow().is_none()
1767 && !cx.has_active_drag()
1768 && hitbox.is_hovered(cx);
1769 let mut was_hovered = was_hovered.borrow_mut();
1770
1771 if is_hovered != *was_hovered {
1772 *was_hovered = is_hovered;
1773 drop(was_hovered);
1774
1775 hover_listener(&is_hovered, cx.deref_mut());
1776 }
1777 });
1778 }
1779
1780 if let Some(tooltip_builder) = self.tooltip_builder.take() {
1781 let active_tooltip = element_state
1782 .active_tooltip
1783 .get_or_insert_with(Default::default)
1784 .clone();
1785 let pending_mouse_down = element_state
1786 .pending_mouse_down
1787 .get_or_insert_with(Default::default)
1788 .clone();
1789 let hitbox = hitbox.clone();
1790
1791 cx.on_mouse_event(move |_: &MouseMoveEvent, phase, cx| {
1792 let is_hovered = pending_mouse_down.borrow().is_none() && hitbox.is_hovered(cx);
1793 if !is_hovered {
1794 active_tooltip.borrow_mut().take();
1795 return;
1796 }
1797
1798 if phase != DispatchPhase::Bubble {
1799 return;
1800 }
1801
1802 if active_tooltip.borrow().is_none() {
1803 let task = cx.spawn({
1804 let active_tooltip = active_tooltip.clone();
1805 let tooltip_builder = tooltip_builder.clone();
1806
1807 move |mut cx| async move {
1808 cx.background_executor().timer(TOOLTIP_DELAY).await;
1809 cx.update(|cx| {
1810 active_tooltip.borrow_mut().replace(ActiveTooltip {
1811 tooltip: Some(AnyTooltip {
1812 view: tooltip_builder(cx),
1813 cursor_offset: cx.mouse_position(),
1814 }),
1815 _task: None,
1816 });
1817 cx.refresh();
1818 })
1819 .ok();
1820 }
1821 });
1822 active_tooltip.borrow_mut().replace(ActiveTooltip {
1823 tooltip: None,
1824 _task: Some(task),
1825 });
1826 }
1827 });
1828
1829 let active_tooltip = element_state
1830 .active_tooltip
1831 .get_or_insert_with(Default::default)
1832 .clone();
1833 cx.on_mouse_event(move |_: &MouseDownEvent, _, _| {
1834 active_tooltip.borrow_mut().take();
1835 });
1836 }
1837
1838 let active_state = element_state
1839 .clicked_state
1840 .get_or_insert_with(Default::default)
1841 .clone();
1842 if active_state.borrow().is_clicked() {
1843 cx.on_mouse_event(move |_: &MouseUpEvent, phase, cx| {
1844 if phase == DispatchPhase::Capture {
1845 *active_state.borrow_mut() = ElementClickedState::default();
1846 cx.refresh();
1847 }
1848 });
1849 } else {
1850 let active_group_hitbox = self
1851 .group_active_style
1852 .as_ref()
1853 .and_then(|group_active| GroupHitboxes::get(&group_active.group, cx));
1854 let hitbox = hitbox.clone();
1855 cx.on_mouse_event(move |_: &MouseDownEvent, phase, cx| {
1856 if phase == DispatchPhase::Bubble && !cx.default_prevented() {
1857 let group_hovered = active_group_hitbox
1858 .map_or(false, |group_hitbox_id| group_hitbox_id.is_hovered(cx));
1859 let element_hovered = hitbox.is_hovered(cx);
1860 if group_hovered || element_hovered {
1861 *active_state.borrow_mut() = ElementClickedState {
1862 group: group_hovered,
1863 element: element_hovered,
1864 };
1865 cx.refresh();
1866 }
1867 }
1868 });
1869 }
1870 }
1871 }
1872
1873 fn paint_keyboard_listeners(&mut self, cx: &mut ElementContext) {
1874 let key_down_listeners = mem::take(&mut self.key_down_listeners);
1875 let key_up_listeners = mem::take(&mut self.key_up_listeners);
1876 let action_listeners = mem::take(&mut self.action_listeners);
1877 if let Some(context) = self.key_context.clone() {
1878 cx.set_key_context(context);
1879 }
1880 if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
1881 cx.set_focus_handle(focus_handle);
1882 }
1883
1884 for listener in key_down_listeners {
1885 cx.on_key_event(move |event: &KeyDownEvent, phase, cx| {
1886 listener(event, phase, cx);
1887 })
1888 }
1889
1890 for listener in key_up_listeners {
1891 cx.on_key_event(move |event: &KeyUpEvent, phase, cx| {
1892 listener(event, phase, cx);
1893 })
1894 }
1895
1896 for (action_type, listener) in action_listeners {
1897 cx.on_action(action_type, listener)
1898 }
1899 }
1900
1901 fn paint_hover_group_handler(&self, cx: &mut ElementContext) {
1902 let group_hitbox = self
1903 .group_hover_style
1904 .as_ref()
1905 .and_then(|group_hover| GroupHitboxes::get(&group_hover.group, cx));
1906
1907 if let Some(group_hitbox) = group_hitbox {
1908 let was_hovered = group_hitbox.is_hovered(cx);
1909 cx.on_mouse_event(move |_: &MouseMoveEvent, phase, cx| {
1910 let hovered = group_hitbox.is_hovered(cx);
1911 if phase == DispatchPhase::Capture && hovered != was_hovered {
1912 cx.refresh();
1913 }
1914 });
1915 }
1916 }
1917
1918 fn paint_scroll_listener(&self, hitbox: &Hitbox, style: &Style, cx: &mut ElementContext) {
1919 if let Some(scroll_offset) = self.scroll_offset.clone() {
1920 let overflow = style.overflow;
1921 let line_height = cx.line_height();
1922 let hitbox = hitbox.clone();
1923 cx.on_mouse_event(move |event: &ScrollWheelEvent, phase, cx| {
1924 if phase == DispatchPhase::Bubble && hitbox.is_hovered(cx) {
1925 let mut scroll_offset = scroll_offset.borrow_mut();
1926 let old_scroll_offset = *scroll_offset;
1927 let delta = event.delta.pixel_delta(line_height);
1928
1929 if overflow.x == Overflow::Scroll {
1930 let mut delta_x = Pixels::ZERO;
1931 if !delta.x.is_zero() {
1932 delta_x = delta.x;
1933 } else if overflow.y != Overflow::Scroll {
1934 delta_x = delta.y;
1935 }
1936
1937 scroll_offset.x += delta_x;
1938 }
1939
1940 if overflow.y == Overflow::Scroll {
1941 let mut delta_y = Pixels::ZERO;
1942 if !delta.y.is_zero() {
1943 delta_y = delta.y;
1944 } else if overflow.x != Overflow::Scroll {
1945 delta_y = delta.x;
1946 }
1947
1948 scroll_offset.y += delta_y;
1949 }
1950
1951 cx.stop_propagation();
1952 if *scroll_offset != old_scroll_offset {
1953 cx.refresh();
1954 }
1955 }
1956 });
1957 }
1958 }
1959
1960 /// Compute the visual style for this element, based on the current bounds and the element's state.
1961 pub fn compute_style(&self, hitbox: Option<&Hitbox>, cx: &mut ElementContext) -> Style {
1962 cx.with_element_state(self.element_id.clone(), |element_state, cx| {
1963 let mut element_state =
1964 element_state.map(|element_state| element_state.unwrap_or_default());
1965 let style = self.compute_style_internal(hitbox, element_state.as_mut(), cx);
1966 (style, element_state)
1967 })
1968 }
1969
1970 /// Called from internal methods that have already called with_element_state.
1971 fn compute_style_internal(
1972 &self,
1973 hitbox: Option<&Hitbox>,
1974 element_state: Option<&mut InteractiveElementState>,
1975 cx: &mut ElementContext,
1976 ) -> Style {
1977 let mut style = Style::default();
1978 style.refine(&self.base_style);
1979
1980 if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
1981 if let Some(in_focus_style) = self.in_focus_style.as_ref() {
1982 if focus_handle.within_focused(cx) {
1983 style.refine(in_focus_style);
1984 }
1985 }
1986
1987 if let Some(focus_style) = self.focus_style.as_ref() {
1988 if focus_handle.is_focused(cx) {
1989 style.refine(focus_style);
1990 }
1991 }
1992 }
1993
1994 if let Some(hitbox) = hitbox {
1995 if !cx.has_active_drag() {
1996 if let Some(group_hover) = self.group_hover_style.as_ref() {
1997 if let Some(group_hitbox_id) =
1998 GroupHitboxes::get(&group_hover.group, cx.deref_mut())
1999 {
2000 if group_hitbox_id.is_hovered(cx) {
2001 style.refine(&group_hover.style);
2002 }
2003 }
2004 }
2005
2006 if let Some(hover_style) = self.hover_style.as_ref() {
2007 if hitbox.is_hovered(cx) {
2008 style.refine(hover_style);
2009 }
2010 }
2011 }
2012
2013 if let Some(drag) = cx.active_drag.take() {
2014 let mut can_drop = true;
2015 if let Some(can_drop_predicate) = &self.can_drop_predicate {
2016 can_drop = can_drop_predicate(drag.value.as_ref(), cx.deref_mut());
2017 }
2018
2019 if can_drop {
2020 for (state_type, group_drag_style) in &self.group_drag_over_styles {
2021 if let Some(group_hitbox_id) =
2022 GroupHitboxes::get(&group_drag_style.group, cx.deref_mut())
2023 {
2024 if *state_type == drag.value.as_ref().type_id()
2025 && group_hitbox_id.is_hovered(cx)
2026 {
2027 style.refine(&group_drag_style.style);
2028 }
2029 }
2030 }
2031
2032 for (state_type, build_drag_over_style) in &self.drag_over_styles {
2033 if *state_type == drag.value.as_ref().type_id() && hitbox.is_hovered(cx) {
2034 style.refine(&build_drag_over_style(drag.value.as_ref(), cx));
2035 }
2036 }
2037 }
2038
2039 cx.active_drag = Some(drag);
2040 }
2041 }
2042
2043 if let Some(element_state) = element_state {
2044 let clicked_state = element_state
2045 .clicked_state
2046 .get_or_insert_with(Default::default)
2047 .borrow();
2048 if clicked_state.group {
2049 if let Some(group) = self.group_active_style.as_ref() {
2050 style.refine(&group.style)
2051 }
2052 }
2053
2054 if let Some(active_style) = self.active_style.as_ref() {
2055 if clicked_state.element {
2056 style.refine(active_style)
2057 }
2058 }
2059 }
2060
2061 style
2062 }
2063}
2064
2065/// The per-frame state of an interactive element. Used for tracking stateful interactions like clicks
2066/// and scroll offsets.
2067#[derive(Default)]
2068pub struct InteractiveElementState {
2069 pub(crate) focus_handle: Option<FocusHandle>,
2070 pub(crate) clicked_state: Option<Rc<RefCell<ElementClickedState>>>,
2071 pub(crate) hover_state: Option<Rc<RefCell<bool>>>,
2072 pub(crate) pending_mouse_down: Option<Rc<RefCell<Option<MouseDownEvent>>>>,
2073 pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
2074 pub(crate) active_tooltip: Option<Rc<RefCell<Option<ActiveTooltip>>>>,
2075}
2076
2077/// The current active tooltip
2078pub struct ActiveTooltip {
2079 pub(crate) tooltip: Option<AnyTooltip>,
2080 pub(crate) _task: Option<Task<()>>,
2081}
2082
2083/// Whether or not the element or a group that contains it is clicked by the mouse.
2084#[derive(Copy, Clone, Default, Eq, PartialEq)]
2085pub struct ElementClickedState {
2086 /// True if this element's group has been clicked, false otherwise
2087 pub group: bool,
2088
2089 /// True if this element has been clicked, false otherwise
2090 pub element: bool,
2091}
2092
2093impl ElementClickedState {
2094 fn is_clicked(&self) -> bool {
2095 self.group || self.element
2096 }
2097}
2098
2099#[derive(Default)]
2100pub(crate) struct GroupHitboxes(HashMap<SharedString, SmallVec<[HitboxId; 1]>>);
2101
2102impl Global for GroupHitboxes {}
2103
2104impl GroupHitboxes {
2105 pub fn get(name: &SharedString, cx: &mut AppContext) -> Option<HitboxId> {
2106 cx.default_global::<Self>()
2107 .0
2108 .get(name)
2109 .and_then(|bounds_stack| bounds_stack.last())
2110 .cloned()
2111 }
2112
2113 pub fn push(name: SharedString, hitbox_id: HitboxId, cx: &mut AppContext) {
2114 cx.default_global::<Self>()
2115 .0
2116 .entry(name)
2117 .or_default()
2118 .push(hitbox_id);
2119 }
2120
2121 pub fn pop(name: &SharedString, cx: &mut AppContext) {
2122 cx.default_global::<Self>().0.get_mut(name).unwrap().pop();
2123 }
2124}
2125
2126/// A wrapper around an element that can be focused.
2127pub struct Focusable<E> {
2128 /// The element that is focusable
2129 pub element: E,
2130}
2131
2132impl<E: InteractiveElement> FocusableElement for Focusable<E> {}
2133
2134impl<E> InteractiveElement for Focusable<E>
2135where
2136 E: InteractiveElement,
2137{
2138 fn interactivity(&mut self) -> &mut Interactivity {
2139 self.element.interactivity()
2140 }
2141}
2142
2143impl<E: StatefulInteractiveElement> StatefulInteractiveElement for Focusable<E> {}
2144
2145impl<E> Styled for Focusable<E>
2146where
2147 E: Styled,
2148{
2149 fn style(&mut self) -> &mut StyleRefinement {
2150 self.element.style()
2151 }
2152}
2153
2154impl<E> Element for Focusable<E>
2155where
2156 E: Element,
2157{
2158 type BeforeLayout = E::BeforeLayout;
2159 type AfterLayout = E::AfterLayout;
2160
2161 fn before_layout(&mut self, cx: &mut ElementContext) -> (LayoutId, Self::BeforeLayout) {
2162 self.element.before_layout(cx)
2163 }
2164
2165 fn after_layout(
2166 &mut self,
2167 bounds: Bounds<Pixels>,
2168 state: &mut Self::BeforeLayout,
2169 cx: &mut ElementContext,
2170 ) -> E::AfterLayout {
2171 self.element.after_layout(bounds, state, cx)
2172 }
2173
2174 fn paint(
2175 &mut self,
2176 bounds: Bounds<Pixels>,
2177 before_layout: &mut Self::BeforeLayout,
2178 after_layout: &mut Self::AfterLayout,
2179 cx: &mut ElementContext,
2180 ) {
2181 self.element.paint(bounds, before_layout, after_layout, cx)
2182 }
2183}
2184
2185impl<E> IntoElement for Focusable<E>
2186where
2187 E: IntoElement,
2188{
2189 type Element = E::Element;
2190
2191 fn into_element(self) -> Self::Element {
2192 self.element.into_element()
2193 }
2194}
2195
2196impl<E> ParentElement for Focusable<E>
2197where
2198 E: ParentElement,
2199{
2200 fn extend(&mut self, elements: impl Iterator<Item = AnyElement>) {
2201 self.element.extend(elements)
2202 }
2203}
2204
2205/// A wrapper around an element that can store state, produced after assigning an ElementId.
2206pub struct Stateful<E> {
2207 element: E,
2208}
2209
2210impl<E> Styled for Stateful<E>
2211where
2212 E: Styled,
2213{
2214 fn style(&mut self) -> &mut StyleRefinement {
2215 self.element.style()
2216 }
2217}
2218
2219impl<E> StatefulInteractiveElement for Stateful<E>
2220where
2221 E: Element,
2222 Self: InteractiveElement,
2223{
2224}
2225
2226impl<E> InteractiveElement for Stateful<E>
2227where
2228 E: InteractiveElement,
2229{
2230 fn interactivity(&mut self) -> &mut Interactivity {
2231 self.element.interactivity()
2232 }
2233}
2234
2235impl<E: FocusableElement> FocusableElement for Stateful<E> {}
2236
2237impl<E> Element for Stateful<E>
2238where
2239 E: Element,
2240{
2241 type BeforeLayout = E::BeforeLayout;
2242 type AfterLayout = E::AfterLayout;
2243
2244 fn before_layout(&mut self, cx: &mut ElementContext) -> (LayoutId, Self::BeforeLayout) {
2245 self.element.before_layout(cx)
2246 }
2247
2248 fn after_layout(
2249 &mut self,
2250 bounds: Bounds<Pixels>,
2251 state: &mut Self::BeforeLayout,
2252 cx: &mut ElementContext,
2253 ) -> E::AfterLayout {
2254 self.element.after_layout(bounds, state, cx)
2255 }
2256
2257 fn paint(
2258 &mut self,
2259 bounds: Bounds<Pixels>,
2260 before_layout: &mut Self::BeforeLayout,
2261 after_layout: &mut Self::AfterLayout,
2262 cx: &mut ElementContext,
2263 ) {
2264 self.element.paint(bounds, before_layout, after_layout, cx);
2265 }
2266}
2267
2268impl<E> IntoElement for Stateful<E>
2269where
2270 E: Element,
2271{
2272 type Element = Self;
2273
2274 fn into_element(self) -> Self::Element {
2275 self
2276 }
2277}
2278
2279impl<E> ParentElement for Stateful<E>
2280where
2281 E: ParentElement,
2282{
2283 fn extend(&mut self, elements: impl Iterator<Item = AnyElement>) {
2284 self.element.extend(elements)
2285 }
2286}
2287
2288#[derive(Default)]
2289struct ScrollHandleState {
2290 offset: Rc<RefCell<Point<Pixels>>>,
2291 bounds: Bounds<Pixels>,
2292 child_bounds: Vec<Bounds<Pixels>>,
2293 requested_scroll_top: Option<(usize, Pixels)>,
2294 overflow: Point<Overflow>,
2295}
2296
2297/// A handle to the scrollable aspects of an element.
2298/// Used for accessing scroll state, like the current scroll offset,
2299/// and for mutating the scroll state, like scrolling to a specific child.
2300#[derive(Clone)]
2301pub struct ScrollHandle(Rc<RefCell<ScrollHandleState>>);
2302
2303impl Default for ScrollHandle {
2304 fn default() -> Self {
2305 Self::new()
2306 }
2307}
2308
2309impl ScrollHandle {
2310 /// Construct a new scroll handle.
2311 pub fn new() -> Self {
2312 Self(Rc::default())
2313 }
2314
2315 /// Get the current scroll offset.
2316 pub fn offset(&self) -> Point<Pixels> {
2317 *self.0.borrow().offset.borrow()
2318 }
2319
2320 /// Get the top child that's scrolled into view.
2321 pub fn top_item(&self) -> usize {
2322 let state = self.0.borrow();
2323 let top = state.bounds.top() - state.offset.borrow().y;
2324
2325 match state.child_bounds.binary_search_by(|bounds| {
2326 if top < bounds.top() {
2327 Ordering::Greater
2328 } else if top > bounds.bottom() {
2329 Ordering::Less
2330 } else {
2331 Ordering::Equal
2332 }
2333 }) {
2334 Ok(ix) => ix,
2335 Err(ix) => ix.min(state.child_bounds.len().saturating_sub(1)),
2336 }
2337 }
2338
2339 /// Get the bounds for a specific child.
2340 pub fn bounds_for_item(&self, ix: usize) -> Option<Bounds<Pixels>> {
2341 self.0.borrow().child_bounds.get(ix).cloned()
2342 }
2343
2344 /// scroll_to_item scrolls the minimal amount to ensure that the child is
2345 /// fully visible
2346 pub fn scroll_to_item(&self, ix: usize) {
2347 let state = self.0.borrow();
2348
2349 let Some(bounds) = state.child_bounds.get(ix) else {
2350 return;
2351 };
2352
2353 let mut scroll_offset = state.offset.borrow_mut();
2354
2355 if state.overflow.y == Overflow::Scroll {
2356 if bounds.top() + scroll_offset.y < state.bounds.top() {
2357 scroll_offset.y = state.bounds.top() - bounds.top();
2358 } else if bounds.bottom() + scroll_offset.y > state.bounds.bottom() {
2359 scroll_offset.y = state.bounds.bottom() - bounds.bottom();
2360 }
2361 }
2362
2363 if state.overflow.x == Overflow::Scroll {
2364 if bounds.left() + scroll_offset.x < state.bounds.left() {
2365 scroll_offset.x = state.bounds.left() - bounds.left();
2366 } else if bounds.right() + scroll_offset.x > state.bounds.right() {
2367 scroll_offset.x = state.bounds.right() - bounds.right();
2368 }
2369 }
2370 }
2371
2372 /// Get the logical scroll top, based on a child index and a pixel offset.
2373 pub fn logical_scroll_top(&self) -> (usize, Pixels) {
2374 let ix = self.top_item();
2375 let state = self.0.borrow();
2376
2377 if let Some(child_bounds) = state.child_bounds.get(ix) {
2378 (
2379 ix,
2380 child_bounds.top() + state.offset.borrow().y - state.bounds.top(),
2381 )
2382 } else {
2383 (ix, px(0.))
2384 }
2385 }
2386
2387 /// Set the logical scroll top, based on a child index and a pixel offset.
2388 pub fn set_logical_scroll_top(&self, ix: usize, px: Pixels) {
2389 self.0.borrow_mut().requested_scroll_top = Some((ix, px));
2390 }
2391}