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, ElementId, FocusHandle, Global, GlobalElementId, Hitbox,
21 HitboxId, IntoElement, IsZero, KeyContext, KeyDownEvent, KeyUpEvent, LayoutId,
22 ModifiersChangedEvent, MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent,
23 ParentElement, Pixels, Point, Render, ScrollWheelEvent, SharedString, Size, Style,
24 StyleRefinement, Styled, Task, TooltipId, View, Visibility, 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 } else {
295 cx.propagate();
296 }
297 }),
298 ));
299 }
300
301 /// Bind the given callback to an action dispatch during the bubble phase
302 /// The imperative API equivalent to [`InteractiveElement::on_action`]
303 ///
304 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
305 pub fn on_action<A: Action>(&mut self, listener: impl Fn(&A, &mut WindowContext) + 'static) {
306 self.action_listeners.push((
307 TypeId::of::<A>(),
308 Box::new(move |action, phase, cx| {
309 let action = action.downcast_ref().unwrap();
310 if phase == DispatchPhase::Bubble {
311 (listener)(action, cx)
312 }
313 }),
314 ));
315 }
316
317 /// Bind the given callback to an action dispatch, based on a dynamic action parameter
318 /// instead of a type parameter. Useful for component libraries that want to expose
319 /// action bindings to their users.
320 /// The imperative API equivalent to [`InteractiveElement::on_boxed_action`]
321 ///
322 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
323 pub fn on_boxed_action(
324 &mut self,
325 action: &dyn Action,
326 listener: impl Fn(&dyn Action, &mut WindowContext) + 'static,
327 ) {
328 let action = action.boxed_clone();
329 self.action_listeners.push((
330 (*action).type_id(),
331 Box::new(move |_, phase, cx| {
332 if phase == DispatchPhase::Bubble {
333 (listener)(&*action, cx)
334 }
335 }),
336 ));
337 }
338
339 /// Bind the given callback to key down events during the bubble phase
340 /// The imperative API equivalent to [`InteractiveElement::on_key_down`]
341 ///
342 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
343 pub fn on_key_down(&mut self, listener: impl Fn(&KeyDownEvent, &mut WindowContext) + 'static) {
344 self.key_down_listeners
345 .push(Box::new(move |event, phase, cx| {
346 if phase == DispatchPhase::Bubble {
347 (listener)(event, cx)
348 }
349 }));
350 }
351
352 /// Bind the given callback to key down events during the capture phase
353 /// The imperative API equivalent to [`InteractiveElement::capture_key_down`]
354 ///
355 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
356 pub fn capture_key_down(
357 &mut self,
358 listener: impl Fn(&KeyDownEvent, &mut WindowContext) + 'static,
359 ) {
360 self.key_down_listeners
361 .push(Box::new(move |event, phase, cx| {
362 if phase == DispatchPhase::Capture {
363 listener(event, cx)
364 }
365 }));
366 }
367
368 /// Bind the given callback to key up events during the bubble phase
369 /// The imperative API equivalent to [`InteractiveElement::on_key_up`]
370 ///
371 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
372 pub fn on_key_up(&mut self, listener: impl Fn(&KeyUpEvent, &mut WindowContext) + 'static) {
373 self.key_up_listeners
374 .push(Box::new(move |event, phase, cx| {
375 if phase == DispatchPhase::Bubble {
376 listener(event, cx)
377 }
378 }));
379 }
380
381 /// Bind the given callback to key up events during the capture phase
382 /// The imperative API equivalent to [`InteractiveElement::on_key_up`]
383 ///
384 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
385 pub fn capture_key_up(&mut self, listener: impl Fn(&KeyUpEvent, &mut WindowContext) + 'static) {
386 self.key_up_listeners
387 .push(Box::new(move |event, phase, cx| {
388 if phase == DispatchPhase::Capture {
389 listener(event, cx)
390 }
391 }));
392 }
393
394 /// Bind the given callback to modifiers changing events.
395 /// The imperative API equivalent to [`InteractiveElement::on_modifiers_changed`]
396 ///
397 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
398 pub fn on_modifiers_changed(
399 &mut self,
400 listener: impl Fn(&ModifiersChangedEvent, &mut WindowContext) + 'static,
401 ) {
402 self.modifiers_changed_listeners
403 .push(Box::new(move |event, cx| listener(event, cx)));
404 }
405
406 /// Bind the given callback to drop events of the given type, whether or not the drag started on this element
407 /// The imperative API equivalent to [`InteractiveElement::on_drop`]
408 ///
409 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
410 pub fn on_drop<T: 'static>(&mut self, listener: impl Fn(&T, &mut WindowContext) + 'static) {
411 self.drop_listeners.push((
412 TypeId::of::<T>(),
413 Box::new(move |dragged_value, cx| {
414 listener(dragged_value.downcast_ref().unwrap(), cx);
415 }),
416 ));
417 }
418
419 /// Use the given predicate to determine whether or not a drop event should be dispatched to this element
420 /// The imperative API equivalent to [`InteractiveElement::can_drop`]
421 pub fn can_drop(&mut self, predicate: impl Fn(&dyn Any, &mut WindowContext) -> bool + 'static) {
422 self.can_drop_predicate = Some(Box::new(predicate));
423 }
424
425 /// Bind the given callback to click events of this element
426 /// The imperative API equivalent to [`StatefulInteractiveElement::on_click`]
427 ///
428 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
429 pub fn on_click(&mut self, listener: impl Fn(&ClickEvent, &mut WindowContext) + 'static)
430 where
431 Self: Sized,
432 {
433 self.click_listeners
434 .push(Box::new(move |event, cx| listener(event, cx)));
435 }
436
437 /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
438 /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
439 /// the [`Self::on_drag_move`] API
440 /// The imperative API equivalent to [`StatefulInteractiveElement::on_drag`]
441 ///
442 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
443 pub fn on_drag<T, W>(
444 &mut self,
445 value: T,
446 constructor: impl Fn(&T, &mut WindowContext) -> View<W> + 'static,
447 ) where
448 Self: Sized,
449 T: 'static,
450 W: 'static + Render,
451 {
452 debug_assert!(
453 self.drag_listener.is_none(),
454 "calling on_drag more than once on the same element is not supported"
455 );
456 self.drag_listener = Some((
457 Box::new(value),
458 Box::new(move |value, cx| constructor(value.downcast_ref().unwrap(), cx).into()),
459 ));
460 }
461
462 /// Bind the given callback on the hover start and end events of this element. Note that the boolean
463 /// passed to the callback is true when the hover starts and false when it ends.
464 /// The imperative API equivalent to [`StatefulInteractiveElement::on_drag`]
465 ///
466 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
467 pub fn on_hover(&mut self, listener: impl Fn(&bool, &mut WindowContext) + 'static)
468 where
469 Self: Sized,
470 {
471 debug_assert!(
472 self.hover_listener.is_none(),
473 "calling on_hover more than once on the same element is not supported"
474 );
475 self.hover_listener = Some(Box::new(listener));
476 }
477
478 /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
479 /// The imperative API equivalent to [`InteractiveElement::tooltip`]
480 pub fn tooltip(&mut self, build_tooltip: impl Fn(&mut WindowContext) -> AnyView + 'static)
481 where
482 Self: Sized,
483 {
484 debug_assert!(
485 self.tooltip_builder.is_none(),
486 "calling tooltip more than once on the same element is not supported"
487 );
488 self.tooltip_builder = Some(TooltipBuilder {
489 build: Rc::new(build_tooltip),
490 hoverable: false,
491 });
492 }
493
494 /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
495 /// The tooltip itself is also hoverable and won't disappear when the user moves the mouse into
496 /// the tooltip. The imperative API equivalent to [`InteractiveElement::hoverable_tooltip`]
497 pub fn hoverable_tooltip(
498 &mut self,
499 build_tooltip: impl Fn(&mut WindowContext) -> AnyView + 'static,
500 ) where
501 Self: Sized,
502 {
503 debug_assert!(
504 self.tooltip_builder.is_none(),
505 "calling tooltip more than once on the same element is not supported"
506 );
507 self.tooltip_builder = Some(TooltipBuilder {
508 build: Rc::new(build_tooltip),
509 hoverable: true,
510 });
511 }
512
513 /// Block the mouse from interacting with this element or any of its children
514 /// The imperative API equivalent to [`InteractiveElement::block_mouse`]
515 pub fn occlude_mouse(&mut self) {
516 self.occlude_mouse = true;
517 }
518}
519
520/// A trait for elements that want to use the standard GPUI event handlers that don't
521/// require any state.
522pub trait InteractiveElement: Sized {
523 /// Retrieve the interactivity state associated with this element
524 fn interactivity(&mut self) -> &mut Interactivity;
525
526 /// Assign this element to a group of elements that can be styled together
527 fn group(mut self, group: impl Into<SharedString>) -> Self {
528 self.interactivity().group = Some(group.into());
529 self
530 }
531
532 /// Assign this element an ID, so that it can be used with interactivity
533 fn id(mut self, id: impl Into<ElementId>) -> Stateful<Self> {
534 self.interactivity().element_id = Some(id.into());
535
536 Stateful { element: self }
537 }
538
539 /// Track the focus state of the given focus handle on this element.
540 /// If the focus handle is focused by the application, this element will
541 /// apply its focused styles.
542 fn track_focus(mut self, focus_handle: &FocusHandle) -> Focusable<Self> {
543 self.interactivity().focusable = true;
544 self.interactivity().tracked_focus_handle = Some(focus_handle.clone());
545 Focusable { element: self }
546 }
547
548 /// Set the keymap context for this element. This will be used to determine
549 /// which action to dispatch from the keymap.
550 fn key_context<C, E>(mut self, key_context: C) -> Self
551 where
552 C: TryInto<KeyContext, Error = E>,
553 E: Debug,
554 {
555 if let Some(key_context) = key_context.try_into().log_err() {
556 self.interactivity().key_context = Some(key_context);
557 }
558 self
559 }
560
561 /// Apply the given style to this element when the mouse hovers over it
562 fn hover(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self {
563 debug_assert!(
564 self.interactivity().hover_style.is_none(),
565 "hover style already set"
566 );
567 self.interactivity().hover_style = Some(Box::new(f(StyleRefinement::default())));
568 self
569 }
570
571 /// Apply the given style to this element when the mouse hovers over a group member
572 fn group_hover(
573 mut self,
574 group_name: impl Into<SharedString>,
575 f: impl FnOnce(StyleRefinement) -> StyleRefinement,
576 ) -> Self {
577 self.interactivity().group_hover_style = Some(GroupStyle {
578 group: group_name.into(),
579 style: Box::new(f(StyleRefinement::default())),
580 });
581 self
582 }
583
584 /// Bind the given callback to the mouse down event for the given mouse button,
585 /// the fluent API equivalent to [`Interactivity::on_mouse_down`]
586 ///
587 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to the view state from this callback.
588 fn on_mouse_down(
589 mut self,
590 button: MouseButton,
591 listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
592 ) -> Self {
593 self.interactivity().on_mouse_down(button, listener);
594 self
595 }
596
597 #[cfg(any(test, feature = "test-support"))]
598 /// Set a key that can be used to look up this element's bounds
599 /// in the [`VisualTestContext::debug_bounds`] map
600 /// This is a noop in release builds
601 fn debug_selector(mut self, f: impl FnOnce() -> String) -> Self {
602 self.interactivity().debug_selector = Some(f());
603 self
604 }
605
606 #[cfg(not(any(test, feature = "test-support")))]
607 /// Set a key that can be used to look up this element's bounds
608 /// in the [`VisualTestContext::debug_bounds`] map
609 /// This is a noop in release builds
610 #[inline]
611 fn debug_selector(self, _: impl FnOnce() -> String) -> Self {
612 self
613 }
614
615 /// Bind the given callback to the mouse down event for any button, during the capture phase
616 /// the fluent API equivalent to [`Interactivity::capture_any_mouse_down`]
617 ///
618 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
619 fn capture_any_mouse_down(
620 mut self,
621 listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
622 ) -> Self {
623 self.interactivity().capture_any_mouse_down(listener);
624 self
625 }
626
627 /// Bind the given callback to the mouse down event for any button, during the capture phase
628 /// the fluent API equivalent to [`Interactivity::on_any_mouse_down`]
629 ///
630 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
631 fn on_any_mouse_down(
632 mut self,
633 listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
634 ) -> Self {
635 self.interactivity().on_any_mouse_down(listener);
636 self
637 }
638
639 /// Bind the given callback to the mouse up event for the given button, during the bubble phase
640 /// the fluent API equivalent to [`Interactivity::on_mouse_up`]
641 ///
642 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
643 fn on_mouse_up(
644 mut self,
645 button: MouseButton,
646 listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
647 ) -> Self {
648 self.interactivity().on_mouse_up(button, listener);
649 self
650 }
651
652 /// Bind the given callback to the mouse up event for any button, during the capture phase
653 /// the fluent API equivalent to [`Interactivity::capture_any_mouse_up`]
654 ///
655 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
656 fn capture_any_mouse_up(
657 mut self,
658 listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
659 ) -> Self {
660 self.interactivity().capture_any_mouse_up(listener);
661 self
662 }
663
664 /// Bind the given callback to the mouse down event, on any button, during the capture phase,
665 /// when the mouse is outside of the bounds of this element.
666 /// The fluent API equivalent to [`Interactivity::on_mouse_down_out`]
667 ///
668 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
669 fn on_mouse_down_out(
670 mut self,
671 listener: impl Fn(&MouseDownEvent, &mut WindowContext) + 'static,
672 ) -> Self {
673 self.interactivity().on_mouse_down_out(listener);
674 self
675 }
676
677 /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
678 /// when the mouse is outside of the bounds of this element.
679 /// The fluent API equivalent to [`Interactivity::on_mouse_up_out`]
680 ///
681 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
682 fn on_mouse_up_out(
683 mut self,
684 button: MouseButton,
685 listener: impl Fn(&MouseUpEvent, &mut WindowContext) + 'static,
686 ) -> Self {
687 self.interactivity().on_mouse_up_out(button, listener);
688 self
689 }
690
691 /// Bind the given callback to the mouse move event, during the bubble phase
692 /// The fluent API equivalent to [`Interactivity::on_mouse_move`]
693 ///
694 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
695 fn on_mouse_move(
696 mut self,
697 listener: impl Fn(&MouseMoveEvent, &mut WindowContext) + 'static,
698 ) -> Self {
699 self.interactivity().on_mouse_move(listener);
700 self
701 }
702
703 /// Bind the given callback to the mouse drag event of the given type. Note that this
704 /// will be called for all move events, inside or outside of this element, as long as the
705 /// drag was started with this element under the mouse. Useful for implementing draggable
706 /// UIs that don't conform to a drag and drop style interaction, like resizing.
707 /// The fluent API equivalent to [`Interactivity::on_drag_move`]
708 ///
709 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
710 fn on_drag_move<T: 'static>(
711 mut self,
712 listener: impl Fn(&DragMoveEvent<T>, &mut WindowContext) + 'static,
713 ) -> Self {
714 self.interactivity().on_drag_move(listener);
715 self
716 }
717
718 /// Bind the given callback to scroll wheel events during the bubble phase
719 /// The fluent API equivalent to [`Interactivity::on_scroll_wheel`]
720 ///
721 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
722 fn on_scroll_wheel(
723 mut self,
724 listener: impl Fn(&ScrollWheelEvent, &mut WindowContext) + 'static,
725 ) -> Self {
726 self.interactivity().on_scroll_wheel(listener);
727 self
728 }
729
730 /// Capture the given action, before normal action dispatch can fire
731 /// The fluent API equivalent to [`Interactivity::on_scroll_wheel`]
732 ///
733 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
734 fn capture_action<A: Action>(
735 mut self,
736 listener: impl Fn(&A, &mut WindowContext) + 'static,
737 ) -> Self {
738 self.interactivity().capture_action(listener);
739 self
740 }
741
742 /// Bind the given callback to an action dispatch during the bubble phase
743 /// The fluent API equivalent to [`Interactivity::on_action`]
744 ///
745 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
746 fn on_action<A: Action>(mut self, listener: impl Fn(&A, &mut WindowContext) + 'static) -> Self {
747 self.interactivity().on_action(listener);
748 self
749 }
750
751 /// Bind the given callback to an action dispatch, based on a dynamic action parameter
752 /// instead of a type parameter. Useful for component libraries that want to expose
753 /// action bindings to their users.
754 /// The fluent API equivalent to [`Interactivity::on_boxed_action`]
755 ///
756 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
757 fn on_boxed_action(
758 mut self,
759 action: &dyn Action,
760 listener: impl Fn(&dyn Action, &mut WindowContext) + 'static,
761 ) -> Self {
762 self.interactivity().on_boxed_action(action, listener);
763 self
764 }
765
766 /// Bind the given callback to key down events during the bubble phase
767 /// The fluent API equivalent to [`Interactivity::on_key_down`]
768 ///
769 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
770 fn on_key_down(
771 mut self,
772 listener: impl Fn(&KeyDownEvent, &mut WindowContext) + 'static,
773 ) -> Self {
774 self.interactivity().on_key_down(listener);
775 self
776 }
777
778 /// Bind the given callback to key down events during the capture phase
779 /// The fluent API equivalent to [`Interactivity::capture_key_down`]
780 ///
781 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
782 fn capture_key_down(
783 mut self,
784 listener: impl Fn(&KeyDownEvent, &mut WindowContext) + 'static,
785 ) -> Self {
786 self.interactivity().capture_key_down(listener);
787 self
788 }
789
790 /// Bind the given callback to key up events during the bubble phase
791 /// The fluent API equivalent to [`Interactivity::on_key_up`]
792 ///
793 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
794 fn on_key_up(mut self, listener: impl Fn(&KeyUpEvent, &mut WindowContext) + 'static) -> Self {
795 self.interactivity().on_key_up(listener);
796 self
797 }
798
799 /// Bind the given callback to key up events during the capture phase
800 /// The fluent API equivalent to [`Interactivity::capture_key_up`]
801 ///
802 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
803 fn capture_key_up(
804 mut self,
805 listener: impl Fn(&KeyUpEvent, &mut WindowContext) + 'static,
806 ) -> Self {
807 self.interactivity().capture_key_up(listener);
808 self
809 }
810
811 /// Bind the given callback to modifiers changing events.
812 /// The fluent API equivalent to [`Interactivity::on_modifiers_changed`]
813 ///
814 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
815 fn on_modifiers_changed(
816 mut self,
817 listener: impl Fn(&ModifiersChangedEvent, &mut WindowContext) + 'static,
818 ) -> Self {
819 self.interactivity().on_modifiers_changed(listener);
820 self
821 }
822
823 /// Apply the given style when the given data type is dragged over this element
824 fn drag_over<S: 'static>(
825 mut self,
826 f: impl 'static + Fn(StyleRefinement, &S, &WindowContext) -> StyleRefinement,
827 ) -> Self {
828 self.interactivity().drag_over_styles.push((
829 TypeId::of::<S>(),
830 Box::new(move |currently_dragged: &dyn Any, cx| {
831 f(
832 StyleRefinement::default(),
833 currently_dragged.downcast_ref::<S>().unwrap(),
834 cx,
835 )
836 }),
837 ));
838 self
839 }
840
841 /// Apply the given style when the given data type is dragged over this element's group
842 fn group_drag_over<S: 'static>(
843 mut self,
844 group_name: impl Into<SharedString>,
845 f: impl FnOnce(StyleRefinement) -> StyleRefinement,
846 ) -> Self {
847 self.interactivity().group_drag_over_styles.push((
848 TypeId::of::<S>(),
849 GroupStyle {
850 group: group_name.into(),
851 style: Box::new(f(StyleRefinement::default())),
852 },
853 ));
854 self
855 }
856
857 /// Bind the given callback to drop events of the given type, whether or not the drag started on this element
858 /// The fluent API equivalent to [`Interactivity::on_drop`]
859 ///
860 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
861 fn on_drop<T: 'static>(mut self, listener: impl Fn(&T, &mut WindowContext) + 'static) -> Self {
862 self.interactivity().on_drop(listener);
863 self
864 }
865
866 /// Use the given predicate to determine whether or not a drop event should be dispatched to this element
867 /// The fluent API equivalent to [`Interactivity::can_drop`]
868 fn can_drop(
869 mut self,
870 predicate: impl Fn(&dyn Any, &mut WindowContext) -> bool + 'static,
871 ) -> Self {
872 self.interactivity().can_drop(predicate);
873 self
874 }
875
876 /// Block the mouse from interacting with this element or any of its children
877 /// The fluent API equivalent to [`Interactivity::block_mouse`]
878 fn occlude(mut self) -> Self {
879 self.interactivity().occlude_mouse();
880 self
881 }
882}
883
884/// A trait for elements that want to use the standard GPUI interactivity features
885/// that require state.
886pub trait StatefulInteractiveElement: InteractiveElement {
887 /// Set this element to focusable.
888 fn focusable(mut self) -> Focusable<Self> {
889 self.interactivity().focusable = true;
890 Focusable { element: self }
891 }
892
893 /// Set the overflow x and y to scroll.
894 fn overflow_scroll(mut self) -> Self {
895 self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
896 self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
897 self
898 }
899
900 /// Set the overflow x to scroll.
901 fn overflow_x_scroll(mut self) -> Self {
902 self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
903 self
904 }
905
906 /// Set the overflow y to scroll.
907 fn overflow_y_scroll(mut self) -> Self {
908 self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
909 self
910 }
911
912 /// Track the scroll state of this element with the given handle.
913 fn track_scroll(mut self, scroll_handle: &ScrollHandle) -> Self {
914 self.interactivity().tracked_scroll_handle = Some(scroll_handle.clone());
915 self
916 }
917
918 /// Set the given styles to be applied when this element is active.
919 fn active(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
920 where
921 Self: Sized,
922 {
923 self.interactivity().active_style = Some(Box::new(f(StyleRefinement::default())));
924 self
925 }
926
927 /// Set the given styles to be applied when this element's group is active.
928 fn group_active(
929 mut self,
930 group_name: impl Into<SharedString>,
931 f: impl FnOnce(StyleRefinement) -> StyleRefinement,
932 ) -> Self
933 where
934 Self: Sized,
935 {
936 self.interactivity().group_active_style = Some(GroupStyle {
937 group: group_name.into(),
938 style: Box::new(f(StyleRefinement::default())),
939 });
940 self
941 }
942
943 /// Bind the given callback to click events of this element
944 /// The fluent API equivalent to [`Interactivity::on_click`]
945 ///
946 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
947 fn on_click(mut self, listener: impl Fn(&ClickEvent, &mut WindowContext) + 'static) -> Self
948 where
949 Self: Sized,
950 {
951 self.interactivity().on_click(listener);
952 self
953 }
954
955 /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
956 /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
957 /// the [`Self::on_drag_move`] API
958 /// The fluent API equivalent to [`Interactivity::on_drag`]
959 ///
960 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
961 fn on_drag<T, W>(
962 mut self,
963 value: T,
964 constructor: impl Fn(&T, &mut WindowContext) -> View<W> + 'static,
965 ) -> Self
966 where
967 Self: Sized,
968 T: 'static,
969 W: 'static + Render,
970 {
971 self.interactivity().on_drag(value, constructor);
972 self
973 }
974
975 /// Bind the given callback on the hover start and end events of this element. Note that the boolean
976 /// passed to the callback is true when the hover starts and false when it ends.
977 /// The fluent API equivalent to [`Interactivity::on_hover`]
978 ///
979 /// See [`ViewContext::listener`](crate::ViewContext::listener) to get access to a view's state from this callback.
980 fn on_hover(mut self, listener: impl Fn(&bool, &mut WindowContext) + 'static) -> Self
981 where
982 Self: Sized,
983 {
984 self.interactivity().on_hover(listener);
985 self
986 }
987
988 /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
989 /// The fluent API equivalent to [`Interactivity::tooltip`]
990 fn tooltip(mut self, build_tooltip: impl Fn(&mut WindowContext) -> AnyView + 'static) -> Self
991 where
992 Self: Sized,
993 {
994 self.interactivity().tooltip(build_tooltip);
995 self
996 }
997
998 /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
999 /// The tooltip itself is also hoverable and won't disappear when the user moves the mouse into
1000 /// the tooltip. The fluent API equivalent to [`Interactivity::hoverable_tooltip`]
1001 fn hoverable_tooltip(
1002 mut self,
1003 build_tooltip: impl Fn(&mut WindowContext) -> AnyView + 'static,
1004 ) -> Self
1005 where
1006 Self: Sized,
1007 {
1008 self.interactivity().hoverable_tooltip(build_tooltip);
1009 self
1010 }
1011}
1012
1013/// A trait for providing focus related APIs to interactive elements
1014pub trait FocusableElement: InteractiveElement {
1015 /// Set the given styles to be applied when this element, specifically, is focused.
1016 fn focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1017 where
1018 Self: Sized,
1019 {
1020 self.interactivity().focus_style = Some(Box::new(f(StyleRefinement::default())));
1021 self
1022 }
1023
1024 /// Set the given styles to be applied when this element is inside another element that is focused.
1025 fn in_focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1026 where
1027 Self: Sized,
1028 {
1029 self.interactivity().in_focus_style = Some(Box::new(f(StyleRefinement::default())));
1030 self
1031 }
1032}
1033
1034pub(crate) type MouseDownListener =
1035 Box<dyn Fn(&MouseDownEvent, DispatchPhase, &Hitbox, &mut WindowContext) + 'static>;
1036pub(crate) type MouseUpListener =
1037 Box<dyn Fn(&MouseUpEvent, DispatchPhase, &Hitbox, &mut WindowContext) + 'static>;
1038
1039pub(crate) type MouseMoveListener =
1040 Box<dyn Fn(&MouseMoveEvent, DispatchPhase, &Hitbox, &mut WindowContext) + 'static>;
1041
1042pub(crate) type ScrollWheelListener =
1043 Box<dyn Fn(&ScrollWheelEvent, DispatchPhase, &Hitbox, &mut WindowContext) + 'static>;
1044
1045pub(crate) type ClickListener = Box<dyn Fn(&ClickEvent, &mut WindowContext) + 'static>;
1046
1047pub(crate) type DragListener = Box<dyn Fn(&dyn Any, &mut WindowContext) -> AnyView + 'static>;
1048
1049type DropListener = Box<dyn Fn(&dyn Any, &mut WindowContext) + 'static>;
1050
1051type CanDropPredicate = Box<dyn Fn(&dyn Any, &mut WindowContext) -> bool + 'static>;
1052
1053pub(crate) struct TooltipBuilder {
1054 build: Rc<dyn Fn(&mut WindowContext) -> AnyView + 'static>,
1055 hoverable: bool,
1056}
1057
1058pub(crate) type KeyDownListener =
1059 Box<dyn Fn(&KeyDownEvent, DispatchPhase, &mut WindowContext) + 'static>;
1060
1061pub(crate) type KeyUpListener =
1062 Box<dyn Fn(&KeyUpEvent, DispatchPhase, &mut WindowContext) + 'static>;
1063
1064pub(crate) type ModifiersChangedListener =
1065 Box<dyn Fn(&ModifiersChangedEvent, &mut WindowContext) + 'static>;
1066
1067pub(crate) type ActionListener = Box<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
1068
1069/// Construct a new [`Div`] element
1070#[track_caller]
1071pub fn div() -> Div {
1072 #[cfg(debug_assertions)]
1073 let interactivity = Interactivity {
1074 location: Some(*core::panic::Location::caller()),
1075 ..Default::default()
1076 };
1077
1078 #[cfg(not(debug_assertions))]
1079 let interactivity = Interactivity::default();
1080
1081 Div {
1082 interactivity,
1083 children: SmallVec::default(),
1084 }
1085}
1086
1087/// A [`Div`] element, the all-in-one element for building complex UIs in GPUI
1088pub struct Div {
1089 interactivity: Interactivity,
1090 children: SmallVec<[AnyElement; 2]>,
1091}
1092
1093/// A frame state for a `Div` element, which contains layout IDs for its children.
1094///
1095/// This struct is used internally by the `Div` element to manage the layout state of its children
1096/// during the UI update cycle. It holds a small vector of `LayoutId` values, each corresponding to
1097/// a child element of the `Div`. These IDs are used to query the layout engine for the computed
1098/// bounds of the children after the layout phase is complete.
1099pub struct DivFrameState {
1100 child_layout_ids: SmallVec<[LayoutId; 2]>,
1101}
1102
1103impl Styled for Div {
1104 fn style(&mut self) -> &mut StyleRefinement {
1105 &mut self.interactivity.base_style
1106 }
1107}
1108
1109impl InteractiveElement for Div {
1110 fn interactivity(&mut self) -> &mut Interactivity {
1111 &mut self.interactivity
1112 }
1113}
1114
1115impl ParentElement for Div {
1116 fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
1117 self.children.extend(elements)
1118 }
1119}
1120
1121impl Element for Div {
1122 type RequestLayoutState = DivFrameState;
1123 type PrepaintState = Option<Hitbox>;
1124
1125 fn id(&self) -> Option<ElementId> {
1126 self.interactivity.element_id.clone()
1127 }
1128
1129 fn request_layout(
1130 &mut self,
1131 global_id: Option<&GlobalElementId>,
1132 cx: &mut WindowContext,
1133 ) -> (LayoutId, Self::RequestLayoutState) {
1134 let mut child_layout_ids = SmallVec::new();
1135 let layout_id = self
1136 .interactivity
1137 .request_layout(global_id, cx, |style, cx| {
1138 cx.with_text_style(style.text_style().cloned(), |cx| {
1139 child_layout_ids = self
1140 .children
1141 .iter_mut()
1142 .map(|child| child.request_layout(cx))
1143 .collect::<SmallVec<_>>();
1144 cx.request_layout(style, child_layout_ids.iter().copied())
1145 })
1146 });
1147 (layout_id, DivFrameState { child_layout_ids })
1148 }
1149
1150 fn prepaint(
1151 &mut self,
1152 global_id: Option<&GlobalElementId>,
1153 bounds: Bounds<Pixels>,
1154 request_layout: &mut Self::RequestLayoutState,
1155 cx: &mut WindowContext,
1156 ) -> Option<Hitbox> {
1157 let mut child_min = point(Pixels::MAX, Pixels::MAX);
1158 let mut child_max = Point::default();
1159 let content_size = if request_layout.child_layout_ids.is_empty() {
1160 bounds.size
1161 } else if let Some(scroll_handle) = self.interactivity.tracked_scroll_handle.as_ref() {
1162 let mut state = scroll_handle.0.borrow_mut();
1163 state.child_bounds = Vec::with_capacity(request_layout.child_layout_ids.len());
1164 state.bounds = bounds;
1165 let requested = state.requested_scroll_top.take();
1166
1167 for (ix, child_layout_id) in request_layout.child_layout_ids.iter().enumerate() {
1168 let child_bounds = cx.layout_bounds(*child_layout_id);
1169 child_min = child_min.min(&child_bounds.origin);
1170 child_max = child_max.max(&child_bounds.lower_right());
1171 state.child_bounds.push(child_bounds);
1172
1173 if let Some(requested) = requested.as_ref() {
1174 if requested.0 == ix {
1175 *state.offset.borrow_mut() =
1176 bounds.origin - (child_bounds.origin - point(px(0.), requested.1));
1177 }
1178 }
1179 }
1180 (child_max - child_min).into()
1181 } else {
1182 for child_layout_id in &request_layout.child_layout_ids {
1183 let child_bounds = cx.layout_bounds(*child_layout_id);
1184 child_min = child_min.min(&child_bounds.origin);
1185 child_max = child_max.max(&child_bounds.lower_right());
1186 }
1187 (child_max - child_min).into()
1188 };
1189
1190 self.interactivity.prepaint(
1191 global_id,
1192 bounds,
1193 content_size,
1194 cx,
1195 |_style, scroll_offset, hitbox, cx| {
1196 cx.with_element_offset(scroll_offset, |cx| {
1197 for child in &mut self.children {
1198 child.prepaint(cx);
1199 }
1200 });
1201 hitbox
1202 },
1203 )
1204 }
1205
1206 fn paint(
1207 &mut self,
1208 global_id: Option<&GlobalElementId>,
1209 bounds: Bounds<Pixels>,
1210 _request_layout: &mut Self::RequestLayoutState,
1211 hitbox: &mut Option<Hitbox>,
1212 cx: &mut WindowContext,
1213 ) {
1214 self.interactivity
1215 .paint(global_id, bounds, hitbox.as_ref(), cx, |_style, cx| {
1216 for child in &mut self.children {
1217 child.paint(cx);
1218 }
1219 });
1220 }
1221}
1222
1223impl IntoElement for Div {
1224 type Element = Self;
1225
1226 fn into_element(self) -> Self::Element {
1227 self
1228 }
1229}
1230
1231/// The interactivity struct. Powers all of the general-purpose
1232/// interactivity in the `Div` element.
1233#[derive(Default)]
1234pub struct Interactivity {
1235 /// The element ID of the element. In id is required to support a stateful subset of the interactivity such as on_click.
1236 pub element_id: Option<ElementId>,
1237 /// Whether the element was clicked. This will only be present after layout.
1238 pub active: Option<bool>,
1239 /// Whether the element was hovered. This will only be present after paint if an hitbox
1240 /// was created for the interactive element.
1241 pub hovered: Option<bool>,
1242 pub(crate) tooltip_id: Option<TooltipId>,
1243 pub(crate) content_size: Size<Pixels>,
1244 pub(crate) key_context: Option<KeyContext>,
1245 pub(crate) focusable: bool,
1246 pub(crate) tracked_focus_handle: Option<FocusHandle>,
1247 pub(crate) tracked_scroll_handle: Option<ScrollHandle>,
1248 pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
1249 pub(crate) group: Option<SharedString>,
1250 /// The base style of the element, before any modifications are applied
1251 /// by focus, active, etc.
1252 pub base_style: Box<StyleRefinement>,
1253 pub(crate) focus_style: Option<Box<StyleRefinement>>,
1254 pub(crate) in_focus_style: Option<Box<StyleRefinement>>,
1255 pub(crate) hover_style: Option<Box<StyleRefinement>>,
1256 pub(crate) group_hover_style: Option<GroupStyle>,
1257 pub(crate) active_style: Option<Box<StyleRefinement>>,
1258 pub(crate) group_active_style: Option<GroupStyle>,
1259 pub(crate) drag_over_styles: Vec<(
1260 TypeId,
1261 Box<dyn Fn(&dyn Any, &mut WindowContext) -> StyleRefinement>,
1262 )>,
1263 pub(crate) group_drag_over_styles: Vec<(TypeId, GroupStyle)>,
1264 pub(crate) mouse_down_listeners: Vec<MouseDownListener>,
1265 pub(crate) mouse_up_listeners: Vec<MouseUpListener>,
1266 pub(crate) mouse_move_listeners: Vec<MouseMoveListener>,
1267 pub(crate) scroll_wheel_listeners: Vec<ScrollWheelListener>,
1268 pub(crate) key_down_listeners: Vec<KeyDownListener>,
1269 pub(crate) key_up_listeners: Vec<KeyUpListener>,
1270 pub(crate) modifiers_changed_listeners: Vec<ModifiersChangedListener>,
1271 pub(crate) action_listeners: Vec<(TypeId, ActionListener)>,
1272 pub(crate) drop_listeners: Vec<(TypeId, DropListener)>,
1273 pub(crate) can_drop_predicate: Option<CanDropPredicate>,
1274 pub(crate) click_listeners: Vec<ClickListener>,
1275 pub(crate) drag_listener: Option<(Box<dyn Any>, DragListener)>,
1276 pub(crate) hover_listener: Option<Box<dyn Fn(&bool, &mut WindowContext)>>,
1277 pub(crate) tooltip_builder: Option<TooltipBuilder>,
1278 pub(crate) occlude_mouse: bool,
1279
1280 #[cfg(debug_assertions)]
1281 pub(crate) location: Option<core::panic::Location<'static>>,
1282
1283 #[cfg(any(test, feature = "test-support"))]
1284 pub(crate) debug_selector: Option<String>,
1285}
1286
1287impl Interactivity {
1288 /// Layout this element according to this interactivity state's configured styles
1289 pub fn request_layout(
1290 &mut self,
1291 global_id: Option<&GlobalElementId>,
1292 cx: &mut WindowContext,
1293 f: impl FnOnce(Style, &mut WindowContext) -> LayoutId,
1294 ) -> LayoutId {
1295 cx.with_optional_element_state::<InteractiveElementState, _>(
1296 global_id,
1297 |element_state, cx| {
1298 let mut element_state =
1299 element_state.map(|element_state| element_state.unwrap_or_default());
1300
1301 if let Some(element_state) = element_state.as_ref() {
1302 if cx.has_active_drag() {
1303 if let Some(pending_mouse_down) = element_state.pending_mouse_down.as_ref()
1304 {
1305 *pending_mouse_down.borrow_mut() = None;
1306 }
1307 if let Some(clicked_state) = element_state.clicked_state.as_ref() {
1308 *clicked_state.borrow_mut() = ElementClickedState::default();
1309 }
1310 }
1311 }
1312
1313 // Ensure we store a focus handle in our element state if we're focusable.
1314 // If there's an explicit focus handle we're tracking, use that. Otherwise
1315 // create a new handle and store it in the element state, which lives for as
1316 // as frames contain an element with this id.
1317 if self.focusable && self.tracked_focus_handle.is_none() {
1318 if let Some(element_state) = element_state.as_mut() {
1319 self.tracked_focus_handle = Some(
1320 element_state
1321 .focus_handle
1322 .get_or_insert_with(|| cx.focus_handle())
1323 .clone(),
1324 );
1325 }
1326 }
1327
1328 if let Some(scroll_handle) = self.tracked_scroll_handle.as_ref() {
1329 self.scroll_offset = Some(scroll_handle.0.borrow().offset.clone());
1330 } else if self.base_style.overflow.x == Some(Overflow::Scroll)
1331 || self.base_style.overflow.y == Some(Overflow::Scroll)
1332 {
1333 if let Some(element_state) = element_state.as_mut() {
1334 self.scroll_offset = Some(
1335 element_state
1336 .scroll_offset
1337 .get_or_insert_with(Rc::default)
1338 .clone(),
1339 );
1340 }
1341 }
1342
1343 let style = self.compute_style_internal(None, element_state.as_mut(), cx);
1344 let layout_id = f(style, cx);
1345 (layout_id, element_state)
1346 },
1347 )
1348 }
1349
1350 /// Commit the bounds of this element according to this interactivity state's configured styles.
1351 pub fn prepaint<R>(
1352 &mut self,
1353 global_id: Option<&GlobalElementId>,
1354 bounds: Bounds<Pixels>,
1355 content_size: Size<Pixels>,
1356 cx: &mut WindowContext,
1357 f: impl FnOnce(&Style, Point<Pixels>, Option<Hitbox>, &mut WindowContext) -> R,
1358 ) -> R {
1359 self.content_size = content_size;
1360 if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
1361 cx.set_focus_handle(focus_handle);
1362 }
1363 cx.with_optional_element_state::<InteractiveElementState, _>(
1364 global_id,
1365 |element_state, cx| {
1366 let mut element_state =
1367 element_state.map(|element_state| element_state.unwrap_or_default());
1368 let style = self.compute_style_internal(None, element_state.as_mut(), cx);
1369
1370 if let Some(element_state) = element_state.as_ref() {
1371 if let Some(clicked_state) = element_state.clicked_state.as_ref() {
1372 let clicked_state = clicked_state.borrow();
1373 self.active = Some(clicked_state.element);
1374 }
1375
1376 if let Some(active_tooltip) = element_state.active_tooltip.as_ref() {
1377 if let Some(active_tooltip) = active_tooltip.borrow().as_ref() {
1378 if let Some(tooltip) = active_tooltip.tooltip.clone() {
1379 self.tooltip_id = Some(cx.set_tooltip(tooltip));
1380 }
1381 }
1382 }
1383 }
1384
1385 cx.with_text_style(style.text_style().cloned(), |cx| {
1386 cx.with_content_mask(style.overflow_mask(bounds, cx.rem_size()), |cx| {
1387 let hitbox = if self.should_insert_hitbox(&style) {
1388 Some(cx.insert_hitbox(bounds, self.occlude_mouse))
1389 } else {
1390 None
1391 };
1392
1393 let scroll_offset = self.clamp_scroll_position(bounds, &style, cx);
1394 let result = f(&style, scroll_offset, hitbox, cx);
1395 (result, element_state)
1396 })
1397 })
1398 },
1399 )
1400 }
1401
1402 fn should_insert_hitbox(&self, style: &Style) -> bool {
1403 self.occlude_mouse
1404 || style.mouse_cursor.is_some()
1405 || self.group.is_some()
1406 || self.scroll_offset.is_some()
1407 || self.tracked_focus_handle.is_some()
1408 || self.hover_style.is_some()
1409 || self.group_hover_style.is_some()
1410 || !self.mouse_up_listeners.is_empty()
1411 || !self.mouse_down_listeners.is_empty()
1412 || !self.mouse_move_listeners.is_empty()
1413 || !self.click_listeners.is_empty()
1414 || !self.scroll_wheel_listeners.is_empty()
1415 || self.drag_listener.is_some()
1416 || !self.drop_listeners.is_empty()
1417 || self.tooltip_builder.is_some()
1418 }
1419
1420 fn clamp_scroll_position(
1421 &self,
1422 bounds: Bounds<Pixels>,
1423 style: &Style,
1424 cx: &mut WindowContext,
1425 ) -> Point<Pixels> {
1426 if let Some(scroll_offset) = self.scroll_offset.as_ref() {
1427 if let Some(scroll_handle) = &self.tracked_scroll_handle {
1428 scroll_handle.0.borrow_mut().overflow = style.overflow;
1429 }
1430
1431 let rem_size = cx.rem_size();
1432 let padding_size = size(
1433 style
1434 .padding
1435 .left
1436 .to_pixels(bounds.size.width.into(), rem_size)
1437 + style
1438 .padding
1439 .right
1440 .to_pixels(bounds.size.width.into(), rem_size),
1441 style
1442 .padding
1443 .top
1444 .to_pixels(bounds.size.height.into(), rem_size)
1445 + style
1446 .padding
1447 .bottom
1448 .to_pixels(bounds.size.height.into(), rem_size),
1449 );
1450 let scroll_max = (self.content_size + padding_size - bounds.size).max(&Size::default());
1451 // Clamp scroll offset in case scroll max is smaller now (e.g., if children
1452 // were removed or the bounds became larger).
1453 let mut scroll_offset = scroll_offset.borrow_mut();
1454 scroll_offset.x = scroll_offset.x.clamp(-scroll_max.width, px(0.));
1455 scroll_offset.y = scroll_offset.y.clamp(-scroll_max.height, px(0.));
1456 *scroll_offset
1457 } else {
1458 Point::default()
1459 }
1460 }
1461
1462 /// Paint this element according to this interactivity state's configured styles
1463 /// and bind the element's mouse and keyboard events.
1464 ///
1465 /// content_size is the size of the content of the element, which may be larger than the
1466 /// element's bounds if the element is scrollable.
1467 ///
1468 /// the final computed style will be passed to the provided function, along
1469 /// with the current scroll offset
1470 pub fn paint(
1471 &mut self,
1472 global_id: Option<&GlobalElementId>,
1473 bounds: Bounds<Pixels>,
1474 hitbox: Option<&Hitbox>,
1475 cx: &mut WindowContext,
1476 f: impl FnOnce(&Style, &mut WindowContext),
1477 ) {
1478 self.hovered = hitbox.map(|hitbox| hitbox.is_hovered(cx));
1479 cx.with_optional_element_state::<InteractiveElementState, _>(
1480 global_id,
1481 |element_state, cx| {
1482 let mut element_state =
1483 element_state.map(|element_state| element_state.unwrap_or_default());
1484
1485 let style = self.compute_style_internal(hitbox, element_state.as_mut(), cx);
1486
1487 #[cfg(any(feature = "test-support", test))]
1488 if let Some(debug_selector) = &self.debug_selector {
1489 cx.window
1490 .next_frame
1491 .debug_bounds
1492 .insert(debug_selector.clone(), bounds);
1493 }
1494
1495 self.paint_hover_group_handler(cx);
1496
1497 if style.visibility == Visibility::Hidden {
1498 return ((), element_state);
1499 }
1500
1501 cx.with_element_opacity(style.opacity, |cx| {
1502 style.paint(bounds, cx, |cx: &mut WindowContext| {
1503 cx.with_text_style(style.text_style().cloned(), |cx| {
1504 cx.with_content_mask(
1505 style.overflow_mask(bounds, cx.rem_size()),
1506 |cx| {
1507 if let Some(hitbox) = hitbox {
1508 #[cfg(debug_assertions)]
1509 self.paint_debug_info(global_id, hitbox, &style, cx);
1510
1511 if !cx.has_active_drag() {
1512 if let Some(mouse_cursor) = style.mouse_cursor {
1513 cx.set_cursor_style(mouse_cursor, hitbox);
1514 }
1515 }
1516
1517 if let Some(group) = self.group.clone() {
1518 GroupHitboxes::push(group, hitbox.id, cx);
1519 }
1520
1521 self.paint_mouse_listeners(
1522 hitbox,
1523 element_state.as_mut(),
1524 cx,
1525 );
1526 self.paint_scroll_listener(hitbox, &style, cx);
1527 }
1528
1529 self.paint_keyboard_listeners(cx);
1530 f(&style, cx);
1531
1532 if hitbox.is_some() {
1533 if let Some(group) = self.group.as_ref() {
1534 GroupHitboxes::pop(group, cx);
1535 }
1536 }
1537 },
1538 );
1539 });
1540 });
1541 });
1542
1543 ((), element_state)
1544 },
1545 );
1546 }
1547
1548 #[cfg(debug_assertions)]
1549 fn paint_debug_info(
1550 &self,
1551 global_id: Option<&GlobalElementId>,
1552 hitbox: &Hitbox,
1553 style: &Style,
1554 cx: &mut WindowContext,
1555 ) {
1556 if global_id.is_some()
1557 && (style.debug || style.debug_below || cx.has_global::<crate::DebugBelow>())
1558 && hitbox.is_hovered(cx)
1559 {
1560 const FONT_SIZE: crate::Pixels = crate::Pixels(10.);
1561 let element_id = format!("{:?}", global_id.unwrap());
1562 let str_len = element_id.len();
1563
1564 let render_debug_text = |cx: &mut WindowContext| {
1565 if let Some(text) = cx
1566 .text_system()
1567 .shape_text(
1568 element_id.into(),
1569 FONT_SIZE,
1570 &[cx.text_style().to_run(str_len)],
1571 None,
1572 )
1573 .ok()
1574 .and_then(|mut text| text.pop())
1575 {
1576 text.paint(hitbox.origin, FONT_SIZE, cx).ok();
1577
1578 let text_bounds = crate::Bounds {
1579 origin: hitbox.origin,
1580 size: text.size(FONT_SIZE),
1581 };
1582 if self.location.is_some()
1583 && text_bounds.contains(&cx.mouse_position())
1584 && cx.modifiers().secondary()
1585 {
1586 let secondary_held = cx.modifiers().secondary();
1587 cx.on_key_event({
1588 move |e: &crate::ModifiersChangedEvent, _phase, cx| {
1589 if e.modifiers.secondary() != secondary_held
1590 && text_bounds.contains(&cx.mouse_position())
1591 {
1592 cx.refresh();
1593 }
1594 }
1595 });
1596
1597 let was_hovered = hitbox.is_hovered(cx);
1598 cx.on_mouse_event({
1599 let hitbox = hitbox.clone();
1600 move |_: &MouseMoveEvent, phase, cx| {
1601 if phase == DispatchPhase::Capture {
1602 let hovered = hitbox.is_hovered(cx);
1603 if hovered != was_hovered {
1604 cx.refresh();
1605 }
1606 }
1607 }
1608 });
1609
1610 cx.on_mouse_event({
1611 let hitbox = hitbox.clone();
1612 let location = self.location.unwrap();
1613 move |e: &crate::MouseDownEvent, phase, cx| {
1614 if text_bounds.contains(&e.position)
1615 && phase.capture()
1616 && hitbox.is_hovered(cx)
1617 {
1618 cx.stop_propagation();
1619 let Ok(dir) = std::env::current_dir() else {
1620 return;
1621 };
1622
1623 eprintln!(
1624 "This element was created at:\n{}:{}:{}",
1625 dir.join(location.file()).to_string_lossy(),
1626 location.line(),
1627 location.column()
1628 );
1629 }
1630 }
1631 });
1632 cx.paint_quad(crate::outline(
1633 crate::Bounds {
1634 origin: hitbox.origin
1635 + crate::point(crate::px(0.), FONT_SIZE - px(2.)),
1636 size: crate::Size {
1637 width: text_bounds.size.width,
1638 height: crate::px(1.),
1639 },
1640 },
1641 crate::red(),
1642 ))
1643 }
1644 }
1645 };
1646
1647 cx.with_text_style(
1648 Some(crate::TextStyleRefinement {
1649 color: Some(crate::red()),
1650 line_height: Some(FONT_SIZE.into()),
1651 background_color: Some(crate::white()),
1652 ..Default::default()
1653 }),
1654 render_debug_text,
1655 )
1656 }
1657 }
1658
1659 fn paint_mouse_listeners(
1660 &mut self,
1661 hitbox: &Hitbox,
1662 element_state: Option<&mut InteractiveElementState>,
1663 cx: &mut WindowContext,
1664 ) {
1665 // If this element can be focused, register a mouse down listener
1666 // that will automatically transfer focus when hitting the element.
1667 // This behavior can be suppressed by using `cx.prevent_default()`.
1668 if let Some(focus_handle) = self.tracked_focus_handle.clone() {
1669 let hitbox = hitbox.clone();
1670 cx.on_mouse_event(move |_: &MouseDownEvent, phase, cx| {
1671 if phase == DispatchPhase::Bubble
1672 && hitbox.is_hovered(cx)
1673 && !cx.default_prevented()
1674 {
1675 cx.focus(&focus_handle);
1676 // If there is a parent that is also focusable, prevent it
1677 // from transferring focus because we already did so.
1678 cx.prevent_default();
1679 }
1680 });
1681 }
1682
1683 for listener in self.mouse_down_listeners.drain(..) {
1684 let hitbox = hitbox.clone();
1685 cx.on_mouse_event(move |event: &MouseDownEvent, phase, cx| {
1686 listener(event, phase, &hitbox, cx);
1687 })
1688 }
1689
1690 for listener in self.mouse_up_listeners.drain(..) {
1691 let hitbox = hitbox.clone();
1692 cx.on_mouse_event(move |event: &MouseUpEvent, phase, cx| {
1693 listener(event, phase, &hitbox, cx);
1694 })
1695 }
1696
1697 for listener in self.mouse_move_listeners.drain(..) {
1698 let hitbox = hitbox.clone();
1699 cx.on_mouse_event(move |event: &MouseMoveEvent, phase, cx| {
1700 listener(event, phase, &hitbox, cx);
1701 })
1702 }
1703
1704 for listener in self.scroll_wheel_listeners.drain(..) {
1705 let hitbox = hitbox.clone();
1706 cx.on_mouse_event(move |event: &ScrollWheelEvent, phase, cx| {
1707 listener(event, phase, &hitbox, cx);
1708 })
1709 }
1710
1711 if self.hover_style.is_some()
1712 || self.base_style.mouse_cursor.is_some()
1713 || cx.active_drag.is_some() && !self.drag_over_styles.is_empty()
1714 {
1715 let hitbox = hitbox.clone();
1716 let was_hovered = hitbox.is_hovered(cx);
1717 cx.on_mouse_event(move |_: &MouseMoveEvent, phase, cx| {
1718 let hovered = hitbox.is_hovered(cx);
1719 if phase == DispatchPhase::Capture && hovered != was_hovered {
1720 cx.refresh();
1721 }
1722 });
1723 }
1724
1725 let mut drag_listener = mem::take(&mut self.drag_listener);
1726 let drop_listeners = mem::take(&mut self.drop_listeners);
1727 let click_listeners = mem::take(&mut self.click_listeners);
1728 let can_drop_predicate = mem::take(&mut self.can_drop_predicate);
1729
1730 if !drop_listeners.is_empty() {
1731 let hitbox = hitbox.clone();
1732 cx.on_mouse_event({
1733 move |_: &MouseUpEvent, phase, cx| {
1734 if let Some(drag) = &cx.active_drag {
1735 if phase == DispatchPhase::Bubble && hitbox.is_hovered(cx) {
1736 let drag_state_type = drag.value.as_ref().type_id();
1737 for (drop_state_type, listener) in &drop_listeners {
1738 if *drop_state_type == drag_state_type {
1739 let drag = cx
1740 .active_drag
1741 .take()
1742 .expect("checked for type drag state type above");
1743
1744 let mut can_drop = true;
1745 if let Some(predicate) = &can_drop_predicate {
1746 can_drop = predicate(drag.value.as_ref(), cx);
1747 }
1748
1749 if can_drop {
1750 listener(drag.value.as_ref(), cx);
1751 cx.refresh();
1752 cx.stop_propagation();
1753 }
1754 }
1755 }
1756 }
1757 }
1758 }
1759 });
1760 }
1761
1762 if let Some(element_state) = element_state {
1763 if !click_listeners.is_empty() || drag_listener.is_some() {
1764 let pending_mouse_down = element_state
1765 .pending_mouse_down
1766 .get_or_insert_with(Default::default)
1767 .clone();
1768
1769 let clicked_state = element_state
1770 .clicked_state
1771 .get_or_insert_with(Default::default)
1772 .clone();
1773
1774 cx.on_mouse_event({
1775 let pending_mouse_down = pending_mouse_down.clone();
1776 let hitbox = hitbox.clone();
1777 move |event: &MouseDownEvent, phase, cx| {
1778 if phase == DispatchPhase::Bubble
1779 && event.button == MouseButton::Left
1780 && hitbox.is_hovered(cx)
1781 {
1782 *pending_mouse_down.borrow_mut() = Some(event.clone());
1783 cx.refresh();
1784 }
1785 }
1786 });
1787
1788 cx.on_mouse_event({
1789 let pending_mouse_down = pending_mouse_down.clone();
1790 let hitbox = hitbox.clone();
1791 move |event: &MouseMoveEvent, phase, cx| {
1792 if phase == DispatchPhase::Capture {
1793 return;
1794 }
1795
1796 let mut pending_mouse_down = pending_mouse_down.borrow_mut();
1797 if let Some(mouse_down) = pending_mouse_down.clone() {
1798 if !cx.has_active_drag()
1799 && (event.position - mouse_down.position).magnitude()
1800 > DRAG_THRESHOLD
1801 {
1802 if let Some((drag_value, drag_listener)) = drag_listener.take() {
1803 *clicked_state.borrow_mut() = ElementClickedState::default();
1804 let cursor_offset = event.position - hitbox.origin;
1805 let drag = (drag_listener)(drag_value.as_ref(), cx);
1806 cx.active_drag = Some(AnyDrag {
1807 view: drag,
1808 value: drag_value,
1809 cursor_offset,
1810 });
1811 pending_mouse_down.take();
1812 cx.refresh();
1813 cx.stop_propagation();
1814 }
1815 }
1816 }
1817 }
1818 });
1819
1820 cx.on_mouse_event({
1821 let mut captured_mouse_down = None;
1822 let hitbox = hitbox.clone();
1823 move |event: &MouseUpEvent, phase, cx| match phase {
1824 // Clear the pending mouse down during the capture phase,
1825 // so that it happens even if another event handler stops
1826 // propagation.
1827 DispatchPhase::Capture => {
1828 let mut pending_mouse_down = pending_mouse_down.borrow_mut();
1829 if pending_mouse_down.is_some() && hitbox.is_hovered(cx) {
1830 captured_mouse_down = pending_mouse_down.take();
1831 cx.refresh();
1832 }
1833 }
1834 // Fire click handlers during the bubble phase.
1835 DispatchPhase::Bubble => {
1836 if let Some(mouse_down) = captured_mouse_down.take() {
1837 let mouse_click = ClickEvent {
1838 down: mouse_down,
1839 up: event.clone(),
1840 };
1841 for listener in &click_listeners {
1842 listener(&mouse_click, cx);
1843 }
1844 }
1845 }
1846 }
1847 });
1848 }
1849
1850 if let Some(hover_listener) = self.hover_listener.take() {
1851 let hitbox = hitbox.clone();
1852 let was_hovered = element_state
1853 .hover_state
1854 .get_or_insert_with(Default::default)
1855 .clone();
1856 let has_mouse_down = element_state
1857 .pending_mouse_down
1858 .get_or_insert_with(Default::default)
1859 .clone();
1860
1861 cx.on_mouse_event(move |_: &MouseMoveEvent, phase, cx| {
1862 if phase != DispatchPhase::Bubble {
1863 return;
1864 }
1865 let is_hovered = has_mouse_down.borrow().is_none()
1866 && !cx.has_active_drag()
1867 && hitbox.is_hovered(cx);
1868 let mut was_hovered = was_hovered.borrow_mut();
1869
1870 if is_hovered != *was_hovered {
1871 *was_hovered = is_hovered;
1872 drop(was_hovered);
1873
1874 hover_listener(&is_hovered, cx);
1875 }
1876 });
1877 }
1878
1879 // Ensure to remove active tooltip if tooltip builder is none
1880 if self.tooltip_builder.is_none() {
1881 element_state.active_tooltip.take();
1882 }
1883
1884 if let Some(tooltip_builder) = self.tooltip_builder.take() {
1885 let tooltip_is_hoverable = tooltip_builder.hoverable;
1886 let active_tooltip = element_state
1887 .active_tooltip
1888 .get_or_insert_with(Default::default)
1889 .clone();
1890 let pending_mouse_down = element_state
1891 .pending_mouse_down
1892 .get_or_insert_with(Default::default)
1893 .clone();
1894
1895 cx.on_mouse_event({
1896 let active_tooltip = active_tooltip.clone();
1897 let hitbox = hitbox.clone();
1898 let tooltip_id = self.tooltip_id;
1899 move |_: &MouseMoveEvent, phase, cx| {
1900 let is_hovered =
1901 pending_mouse_down.borrow().is_none() && hitbox.is_hovered(cx);
1902 let tooltip_is_hovered =
1903 tooltip_id.map_or(false, |tooltip_id| tooltip_id.is_hovered(cx));
1904 if !is_hovered && (!tooltip_is_hoverable || !tooltip_is_hovered) {
1905 if active_tooltip.borrow_mut().take().is_some() {
1906 cx.refresh();
1907 }
1908
1909 return;
1910 }
1911
1912 if phase != DispatchPhase::Bubble {
1913 return;
1914 }
1915
1916 if active_tooltip.borrow().is_none() {
1917 let task = cx.spawn({
1918 let active_tooltip = active_tooltip.clone();
1919 let build_tooltip = tooltip_builder.build.clone();
1920 move |mut cx| async move {
1921 cx.background_executor().timer(TOOLTIP_DELAY).await;
1922 cx.update(|cx| {
1923 active_tooltip.borrow_mut().replace(ActiveTooltip {
1924 tooltip: Some(AnyTooltip {
1925 view: build_tooltip(cx),
1926 mouse_position: cx.mouse_position(),
1927 }),
1928 _task: None,
1929 });
1930 cx.refresh();
1931 })
1932 .ok();
1933 }
1934 });
1935 active_tooltip.borrow_mut().replace(ActiveTooltip {
1936 tooltip: None,
1937 _task: Some(task),
1938 });
1939 }
1940 }
1941 });
1942
1943 cx.on_mouse_event({
1944 let active_tooltip = active_tooltip.clone();
1945 let tooltip_id = self.tooltip_id;
1946 move |_: &MouseDownEvent, _, cx| {
1947 let tooltip_is_hovered =
1948 tooltip_id.map_or(false, |tooltip_id| tooltip_id.is_hovered(cx));
1949
1950 if (!tooltip_is_hoverable || !tooltip_is_hovered)
1951 && active_tooltip.borrow_mut().take().is_some()
1952 {
1953 cx.refresh();
1954 }
1955 }
1956 });
1957
1958 cx.on_mouse_event({
1959 let active_tooltip = active_tooltip.clone();
1960 let tooltip_id = self.tooltip_id;
1961 move |_: &ScrollWheelEvent, _, cx| {
1962 let tooltip_is_hovered =
1963 tooltip_id.map_or(false, |tooltip_id| tooltip_id.is_hovered(cx));
1964 if (!tooltip_is_hoverable || !tooltip_is_hovered)
1965 && active_tooltip.borrow_mut().take().is_some()
1966 {
1967 cx.refresh();
1968 }
1969 }
1970 })
1971 }
1972
1973 let active_state = element_state
1974 .clicked_state
1975 .get_or_insert_with(Default::default)
1976 .clone();
1977 if active_state.borrow().is_clicked() {
1978 cx.on_mouse_event(move |_: &MouseUpEvent, phase, cx| {
1979 if phase == DispatchPhase::Capture {
1980 *active_state.borrow_mut() = ElementClickedState::default();
1981 cx.refresh();
1982 }
1983 });
1984 } else {
1985 let active_group_hitbox = self
1986 .group_active_style
1987 .as_ref()
1988 .and_then(|group_active| GroupHitboxes::get(&group_active.group, cx));
1989 let hitbox = hitbox.clone();
1990 cx.on_mouse_event(move |_: &MouseDownEvent, phase, cx| {
1991 if phase == DispatchPhase::Bubble && !cx.default_prevented() {
1992 let group_hovered = active_group_hitbox
1993 .map_or(false, |group_hitbox_id| group_hitbox_id.is_hovered(cx));
1994 let element_hovered = hitbox.is_hovered(cx);
1995 if group_hovered || element_hovered {
1996 *active_state.borrow_mut() = ElementClickedState {
1997 group: group_hovered,
1998 element: element_hovered,
1999 };
2000 cx.refresh();
2001 }
2002 }
2003 });
2004 }
2005 }
2006 }
2007
2008 fn paint_keyboard_listeners(&mut self, cx: &mut WindowContext) {
2009 let key_down_listeners = mem::take(&mut self.key_down_listeners);
2010 let key_up_listeners = mem::take(&mut self.key_up_listeners);
2011 let modifiers_changed_listeners = mem::take(&mut self.modifiers_changed_listeners);
2012 let action_listeners = mem::take(&mut self.action_listeners);
2013 if let Some(context) = self.key_context.clone() {
2014 cx.set_key_context(context);
2015 }
2016
2017 for listener in key_down_listeners {
2018 cx.on_key_event(move |event: &KeyDownEvent, phase, cx| {
2019 listener(event, phase, cx);
2020 })
2021 }
2022
2023 for listener in key_up_listeners {
2024 cx.on_key_event(move |event: &KeyUpEvent, phase, cx| {
2025 listener(event, phase, cx);
2026 })
2027 }
2028
2029 for listener in modifiers_changed_listeners {
2030 cx.on_modifiers_changed(move |event: &ModifiersChangedEvent, cx| {
2031 listener(event, cx);
2032 })
2033 }
2034
2035 for (action_type, listener) in action_listeners {
2036 cx.on_action(action_type, listener)
2037 }
2038 }
2039
2040 fn paint_hover_group_handler(&self, cx: &mut WindowContext) {
2041 let group_hitbox = self
2042 .group_hover_style
2043 .as_ref()
2044 .and_then(|group_hover| GroupHitboxes::get(&group_hover.group, cx));
2045
2046 if let Some(group_hitbox) = group_hitbox {
2047 let was_hovered = group_hitbox.is_hovered(cx);
2048 cx.on_mouse_event(move |_: &MouseMoveEvent, phase, cx| {
2049 let hovered = group_hitbox.is_hovered(cx);
2050 if phase == DispatchPhase::Capture && hovered != was_hovered {
2051 cx.refresh();
2052 }
2053 });
2054 }
2055 }
2056
2057 fn paint_scroll_listener(&self, hitbox: &Hitbox, style: &Style, cx: &mut WindowContext) {
2058 if let Some(scroll_offset) = self.scroll_offset.clone() {
2059 let overflow = style.overflow;
2060 let allow_concurrent_scroll = style.allow_concurrent_scroll;
2061 let line_height = cx.line_height();
2062 let hitbox = hitbox.clone();
2063 cx.on_mouse_event(move |event: &ScrollWheelEvent, phase, cx| {
2064 if phase == DispatchPhase::Bubble && hitbox.is_hovered(cx) {
2065 let mut scroll_offset = scroll_offset.borrow_mut();
2066 let old_scroll_offset = *scroll_offset;
2067 let delta = event.delta.pixel_delta(line_height);
2068
2069 let mut delta_x = Pixels::ZERO;
2070 if overflow.x == Overflow::Scroll {
2071 if !delta.x.is_zero() {
2072 delta_x = delta.x;
2073 } else if overflow.y != Overflow::Scroll {
2074 delta_x = delta.y;
2075 }
2076 }
2077 let mut delta_y = Pixels::ZERO;
2078 if overflow.y == Overflow::Scroll {
2079 if !delta.y.is_zero() {
2080 delta_y = delta.y;
2081 } else if overflow.x != Overflow::Scroll {
2082 delta_y = delta.x;
2083 }
2084 }
2085 if !allow_concurrent_scroll && !delta_x.is_zero() && !delta_y.is_zero() {
2086 if delta_x.abs() > delta_y.abs() {
2087 delta_y = Pixels::ZERO;
2088 } else {
2089 delta_x = Pixels::ZERO;
2090 }
2091 }
2092 scroll_offset.y += delta_y;
2093 scroll_offset.x += delta_x;
2094
2095 cx.stop_propagation();
2096 if *scroll_offset != old_scroll_offset {
2097 cx.refresh();
2098 }
2099 }
2100 });
2101 }
2102 }
2103
2104 /// Compute the visual style for this element, based on the current bounds and the element's state.
2105 pub fn compute_style(
2106 &self,
2107 global_id: Option<&GlobalElementId>,
2108 hitbox: Option<&Hitbox>,
2109 cx: &mut WindowContext,
2110 ) -> Style {
2111 cx.with_optional_element_state(global_id, |element_state, cx| {
2112 let mut element_state =
2113 element_state.map(|element_state| element_state.unwrap_or_default());
2114 let style = self.compute_style_internal(hitbox, element_state.as_mut(), cx);
2115 (style, element_state)
2116 })
2117 }
2118
2119 /// Called from internal methods that have already called with_element_state.
2120 fn compute_style_internal(
2121 &self,
2122 hitbox: Option<&Hitbox>,
2123 element_state: Option<&mut InteractiveElementState>,
2124 cx: &mut WindowContext,
2125 ) -> Style {
2126 let mut style = Style::default();
2127 style.refine(&self.base_style);
2128
2129 if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
2130 if let Some(in_focus_style) = self.in_focus_style.as_ref() {
2131 if focus_handle.within_focused(cx) {
2132 style.refine(in_focus_style);
2133 }
2134 }
2135
2136 if let Some(focus_style) = self.focus_style.as_ref() {
2137 if focus_handle.is_focused(cx) {
2138 style.refine(focus_style);
2139 }
2140 }
2141 }
2142
2143 if let Some(hitbox) = hitbox {
2144 if !cx.has_active_drag() {
2145 if let Some(group_hover) = self.group_hover_style.as_ref() {
2146 if let Some(group_hitbox_id) =
2147 GroupHitboxes::get(&group_hover.group, cx.deref_mut())
2148 {
2149 if group_hitbox_id.is_hovered(cx) {
2150 style.refine(&group_hover.style);
2151 }
2152 }
2153 }
2154
2155 if let Some(hover_style) = self.hover_style.as_ref() {
2156 if hitbox.is_hovered(cx) {
2157 style.refine(hover_style);
2158 }
2159 }
2160 }
2161
2162 if let Some(drag) = cx.active_drag.take() {
2163 let mut can_drop = true;
2164 if let Some(can_drop_predicate) = &self.can_drop_predicate {
2165 can_drop = can_drop_predicate(drag.value.as_ref(), cx);
2166 }
2167
2168 if can_drop {
2169 for (state_type, group_drag_style) in &self.group_drag_over_styles {
2170 if let Some(group_hitbox_id) =
2171 GroupHitboxes::get(&group_drag_style.group, cx.deref_mut())
2172 {
2173 if *state_type == drag.value.as_ref().type_id()
2174 && group_hitbox_id.is_hovered(cx)
2175 {
2176 style.refine(&group_drag_style.style);
2177 }
2178 }
2179 }
2180
2181 for (state_type, build_drag_over_style) in &self.drag_over_styles {
2182 if *state_type == drag.value.as_ref().type_id() && hitbox.is_hovered(cx) {
2183 style.refine(&build_drag_over_style(drag.value.as_ref(), cx));
2184 }
2185 }
2186 }
2187
2188 cx.active_drag = Some(drag);
2189 }
2190 }
2191
2192 if let Some(element_state) = element_state {
2193 let clicked_state = element_state
2194 .clicked_state
2195 .get_or_insert_with(Default::default)
2196 .borrow();
2197 if clicked_state.group {
2198 if let Some(group) = self.group_active_style.as_ref() {
2199 style.refine(&group.style)
2200 }
2201 }
2202
2203 if let Some(active_style) = self.active_style.as_ref() {
2204 if clicked_state.element {
2205 style.refine(active_style)
2206 }
2207 }
2208 }
2209
2210 style
2211 }
2212}
2213
2214/// The per-frame state of an interactive element. Used for tracking stateful interactions like clicks
2215/// and scroll offsets.
2216#[derive(Default)]
2217pub struct InteractiveElementState {
2218 pub(crate) focus_handle: Option<FocusHandle>,
2219 pub(crate) clicked_state: Option<Rc<RefCell<ElementClickedState>>>,
2220 pub(crate) hover_state: Option<Rc<RefCell<bool>>>,
2221 pub(crate) pending_mouse_down: Option<Rc<RefCell<Option<MouseDownEvent>>>>,
2222 pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
2223 pub(crate) active_tooltip: Option<Rc<RefCell<Option<ActiveTooltip>>>>,
2224}
2225
2226/// The current active tooltip
2227pub struct ActiveTooltip {
2228 pub(crate) tooltip: Option<AnyTooltip>,
2229 pub(crate) _task: Option<Task<()>>,
2230}
2231
2232/// Whether or not the element or a group that contains it is clicked by the mouse.
2233#[derive(Copy, Clone, Default, Eq, PartialEq)]
2234pub struct ElementClickedState {
2235 /// True if this element's group has been clicked, false otherwise
2236 pub group: bool,
2237
2238 /// True if this element has been clicked, false otherwise
2239 pub element: bool,
2240}
2241
2242impl ElementClickedState {
2243 fn is_clicked(&self) -> bool {
2244 self.group || self.element
2245 }
2246}
2247
2248#[derive(Default)]
2249pub(crate) struct GroupHitboxes(HashMap<SharedString, SmallVec<[HitboxId; 1]>>);
2250
2251impl Global for GroupHitboxes {}
2252
2253impl GroupHitboxes {
2254 pub fn get(name: &SharedString, cx: &mut AppContext) -> Option<HitboxId> {
2255 cx.default_global::<Self>()
2256 .0
2257 .get(name)
2258 .and_then(|bounds_stack| bounds_stack.last())
2259 .cloned()
2260 }
2261
2262 pub fn push(name: SharedString, hitbox_id: HitboxId, cx: &mut AppContext) {
2263 cx.default_global::<Self>()
2264 .0
2265 .entry(name)
2266 .or_default()
2267 .push(hitbox_id);
2268 }
2269
2270 pub fn pop(name: &SharedString, cx: &mut AppContext) {
2271 cx.default_global::<Self>().0.get_mut(name).unwrap().pop();
2272 }
2273}
2274
2275/// A wrapper around an element that can be focused.
2276pub struct Focusable<E> {
2277 /// The element that is focusable
2278 pub element: E,
2279}
2280
2281impl<E: InteractiveElement> FocusableElement for Focusable<E> {}
2282
2283impl<E> InteractiveElement for Focusable<E>
2284where
2285 E: InteractiveElement,
2286{
2287 fn interactivity(&mut self) -> &mut Interactivity {
2288 self.element.interactivity()
2289 }
2290}
2291
2292impl<E: StatefulInteractiveElement> StatefulInteractiveElement for Focusable<E> {}
2293
2294impl<E> Styled for Focusable<E>
2295where
2296 E: Styled,
2297{
2298 fn style(&mut self) -> &mut StyleRefinement {
2299 self.element.style()
2300 }
2301}
2302
2303impl<E> Element for Focusable<E>
2304where
2305 E: Element,
2306{
2307 type RequestLayoutState = E::RequestLayoutState;
2308 type PrepaintState = E::PrepaintState;
2309
2310 fn id(&self) -> Option<ElementId> {
2311 self.element.id()
2312 }
2313
2314 fn request_layout(
2315 &mut self,
2316 id: Option<&GlobalElementId>,
2317 cx: &mut WindowContext,
2318 ) -> (LayoutId, Self::RequestLayoutState) {
2319 self.element.request_layout(id, cx)
2320 }
2321
2322 fn prepaint(
2323 &mut self,
2324 id: Option<&GlobalElementId>,
2325 bounds: Bounds<Pixels>,
2326 state: &mut Self::RequestLayoutState,
2327 cx: &mut WindowContext,
2328 ) -> E::PrepaintState {
2329 self.element.prepaint(id, bounds, state, cx)
2330 }
2331
2332 fn paint(
2333 &mut self,
2334 id: Option<&GlobalElementId>,
2335 bounds: Bounds<Pixels>,
2336 request_layout: &mut Self::RequestLayoutState,
2337 prepaint: &mut Self::PrepaintState,
2338 cx: &mut WindowContext,
2339 ) {
2340 self.element.paint(id, bounds, request_layout, prepaint, cx)
2341 }
2342}
2343
2344impl<E> IntoElement for Focusable<E>
2345where
2346 E: IntoElement,
2347{
2348 type Element = E::Element;
2349
2350 fn into_element(self) -> Self::Element {
2351 self.element.into_element()
2352 }
2353}
2354
2355impl<E> ParentElement for Focusable<E>
2356where
2357 E: ParentElement,
2358{
2359 fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
2360 self.element.extend(elements)
2361 }
2362}
2363
2364/// A wrapper around an element that can store state, produced after assigning an ElementId.
2365pub struct Stateful<E> {
2366 element: E,
2367}
2368
2369impl<E> Styled for Stateful<E>
2370where
2371 E: Styled,
2372{
2373 fn style(&mut self) -> &mut StyleRefinement {
2374 self.element.style()
2375 }
2376}
2377
2378impl<E> StatefulInteractiveElement for Stateful<E>
2379where
2380 E: Element,
2381 Self: InteractiveElement,
2382{
2383}
2384
2385impl<E> InteractiveElement for Stateful<E>
2386where
2387 E: InteractiveElement,
2388{
2389 fn interactivity(&mut self) -> &mut Interactivity {
2390 self.element.interactivity()
2391 }
2392}
2393
2394impl<E: FocusableElement> FocusableElement for Stateful<E> {}
2395
2396impl<E> Element for Stateful<E>
2397where
2398 E: Element,
2399{
2400 type RequestLayoutState = E::RequestLayoutState;
2401 type PrepaintState = E::PrepaintState;
2402
2403 fn id(&self) -> Option<ElementId> {
2404 self.element.id()
2405 }
2406
2407 fn request_layout(
2408 &mut self,
2409 id: Option<&GlobalElementId>,
2410 cx: &mut WindowContext,
2411 ) -> (LayoutId, Self::RequestLayoutState) {
2412 self.element.request_layout(id, cx)
2413 }
2414
2415 fn prepaint(
2416 &mut self,
2417 id: Option<&GlobalElementId>,
2418 bounds: Bounds<Pixels>,
2419 state: &mut Self::RequestLayoutState,
2420 cx: &mut WindowContext,
2421 ) -> E::PrepaintState {
2422 self.element.prepaint(id, bounds, state, cx)
2423 }
2424
2425 fn paint(
2426 &mut self,
2427 id: Option<&GlobalElementId>,
2428 bounds: Bounds<Pixels>,
2429 request_layout: &mut Self::RequestLayoutState,
2430 prepaint: &mut Self::PrepaintState,
2431 cx: &mut WindowContext,
2432 ) {
2433 self.element.paint(id, bounds, request_layout, prepaint, cx);
2434 }
2435}
2436
2437impl<E> IntoElement for Stateful<E>
2438where
2439 E: Element,
2440{
2441 type Element = Self;
2442
2443 fn into_element(self) -> Self::Element {
2444 self
2445 }
2446}
2447
2448impl<E> ParentElement for Stateful<E>
2449where
2450 E: ParentElement,
2451{
2452 fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
2453 self.element.extend(elements)
2454 }
2455}
2456
2457#[derive(Default, Debug)]
2458struct ScrollHandleState {
2459 offset: Rc<RefCell<Point<Pixels>>>,
2460 bounds: Bounds<Pixels>,
2461 child_bounds: Vec<Bounds<Pixels>>,
2462 requested_scroll_top: Option<(usize, Pixels)>,
2463 overflow: Point<Overflow>,
2464}
2465
2466/// A handle to the scrollable aspects of an element.
2467/// Used for accessing scroll state, like the current scroll offset,
2468/// and for mutating the scroll state, like scrolling to a specific child.
2469#[derive(Clone, Debug)]
2470pub struct ScrollHandle(Rc<RefCell<ScrollHandleState>>);
2471
2472impl Default for ScrollHandle {
2473 fn default() -> Self {
2474 Self::new()
2475 }
2476}
2477
2478impl ScrollHandle {
2479 /// Construct a new scroll handle.
2480 pub fn new() -> Self {
2481 Self(Rc::default())
2482 }
2483
2484 /// Get the current scroll offset.
2485 pub fn offset(&self) -> Point<Pixels> {
2486 *self.0.borrow().offset.borrow()
2487 }
2488
2489 /// Get the top child that's scrolled into view.
2490 pub fn top_item(&self) -> usize {
2491 let state = self.0.borrow();
2492 let top = state.bounds.top() - state.offset.borrow().y;
2493
2494 match state.child_bounds.binary_search_by(|bounds| {
2495 if top < bounds.top() {
2496 Ordering::Greater
2497 } else if top > bounds.bottom() {
2498 Ordering::Less
2499 } else {
2500 Ordering::Equal
2501 }
2502 }) {
2503 Ok(ix) => ix,
2504 Err(ix) => ix.min(state.child_bounds.len().saturating_sub(1)),
2505 }
2506 }
2507
2508 /// Return the bounds into which this child is painted
2509 pub fn bounds(&self) -> Bounds<Pixels> {
2510 self.0.borrow().bounds
2511 }
2512
2513 /// Set the bounds into which this child is painted
2514 pub(super) fn set_bounds(&self, bounds: Bounds<Pixels>) {
2515 self.0.borrow_mut().bounds = bounds;
2516 }
2517
2518 /// Get the bounds for a specific child.
2519 pub fn bounds_for_item(&self, ix: usize) -> Option<Bounds<Pixels>> {
2520 self.0.borrow().child_bounds.get(ix).cloned()
2521 }
2522
2523 /// scroll_to_item scrolls the minimal amount to ensure that the child is
2524 /// fully visible
2525 pub fn scroll_to_item(&self, ix: usize) {
2526 let state = self.0.borrow();
2527
2528 let Some(bounds) = state.child_bounds.get(ix) else {
2529 return;
2530 };
2531
2532 let mut scroll_offset = state.offset.borrow_mut();
2533
2534 if state.overflow.y == Overflow::Scroll {
2535 if bounds.top() + scroll_offset.y < state.bounds.top() {
2536 scroll_offset.y = state.bounds.top() - bounds.top();
2537 } else if bounds.bottom() + scroll_offset.y > state.bounds.bottom() {
2538 scroll_offset.y = state.bounds.bottom() - bounds.bottom();
2539 }
2540 }
2541
2542 if state.overflow.x == Overflow::Scroll {
2543 if bounds.left() + scroll_offset.x < state.bounds.left() {
2544 scroll_offset.x = state.bounds.left() - bounds.left();
2545 } else if bounds.right() + scroll_offset.x > state.bounds.right() {
2546 scroll_offset.x = state.bounds.right() - bounds.right();
2547 }
2548 }
2549 }
2550
2551 /// Set the offset explicitly. The offset is the distance from the top left of the
2552 /// parent container to the top left of the first child.
2553 /// As you scroll further down the offset becomes more negative.
2554 pub fn set_offset(&self, mut position: Point<Pixels>) {
2555 let state = self.0.borrow();
2556 *state.offset.borrow_mut() = position;
2557 }
2558
2559 /// Get the logical scroll top, based on a child index and a pixel offset.
2560 pub fn logical_scroll_top(&self) -> (usize, Pixels) {
2561 let ix = self.top_item();
2562 let state = self.0.borrow();
2563
2564 if let Some(child_bounds) = state.child_bounds.get(ix) {
2565 (
2566 ix,
2567 child_bounds.top() + state.offset.borrow().y - state.bounds.top(),
2568 )
2569 } else {
2570 (ix, px(0.))
2571 }
2572 }
2573
2574 /// Set the logical scroll top, based on a child index and a pixel offset.
2575 pub fn set_logical_scroll_top(&self, ix: usize, px: Pixels) {
2576 self.0.borrow_mut().requested_scroll_top = Some((ix, px));
2577 }
2578
2579 /// Get the count of children for scrollable item.
2580 pub fn children_count(&self) -> usize {
2581 self.0.borrow().child_bounds.len()
2582 }
2583}