1use crate::{
2 Active, Anonymous, AnyElement, AppContext, BorrowWindow, Bounds, Click, DispatchPhase, Element,
3 ElementFocusability, ElementId, ElementIdentity, EventListeners, Focus, FocusHandle, Focusable,
4 Hover, Identified, Interactive, IntoAnyElement, LayoutId, MouseClickEvent, MouseDownEvent,
5 MouseMoveEvent, MouseUpEvent, NonFocusable, Overflow, ParentElement, Pixels, Point,
6 ScrollWheelEvent, SharedString, Style, StyleRefinement, Styled, ViewContext,
7};
8use collections::HashMap;
9use parking_lot::Mutex;
10use refineable::Refineable;
11use smallvec::SmallVec;
12use std::{mem, sync::Arc};
13
14#[derive(Default)]
15pub struct DivState {
16 active_state: Arc<Mutex<ActiveState>>,
17 pending_click: Arc<Mutex<Option<MouseDownEvent>>>,
18}
19
20#[derive(Copy, Clone, Default, Eq, PartialEq)]
21struct ActiveState {
22 group: bool,
23 element: bool,
24}
25
26impl ActiveState {
27 pub fn is_none(&self) -> bool {
28 !self.group && !self.element
29 }
30}
31
32#[derive(Default)]
33struct GroupBounds(HashMap<SharedString, SmallVec<[Bounds<Pixels>; 1]>>);
34
35pub fn group_bounds(name: &SharedString, cx: &mut AppContext) -> Option<Bounds<Pixels>> {
36 cx.default_global::<GroupBounds>()
37 .0
38 .get(name)
39 .and_then(|bounds_stack| bounds_stack.last().cloned())
40}
41
42#[derive(Default, Clone)]
43pub struct ScrollState(Arc<Mutex<Point<Pixels>>>);
44
45impl ScrollState {
46 pub fn x(&self) -> Pixels {
47 self.0.lock().x
48 }
49
50 pub fn set_x(&self, value: Pixels) {
51 self.0.lock().x = value;
52 }
53
54 pub fn y(&self) -> Pixels {
55 self.0.lock().y
56 }
57
58 pub fn set_y(&self, value: Pixels) {
59 self.0.lock().y = value;
60 }
61}
62
63pub fn div<V>() -> Div<V, Anonymous, NonFocusable>
64where
65 V: 'static + Send + Sync,
66{
67 Div {
68 identity: Anonymous,
69 focusability: NonFocusable,
70 children: SmallVec::new(),
71 group: None,
72 base_style: StyleRefinement::default(),
73 hover_style: StyleRefinement::default(),
74 group_hover: None,
75 active_style: StyleRefinement::default(),
76 group_active: None,
77 focus_style: StyleRefinement::default(),
78 focus_in_style: StyleRefinement::default(),
79 in_focus_style: StyleRefinement::default(),
80 listeners: EventListeners::default(),
81 }
82}
83
84pub struct Div<
85 V: 'static + Send + Sync,
86 I: ElementIdentity = Anonymous,
87 F: ElementFocusability = NonFocusable,
88> {
89 identity: I,
90 focusability: F,
91 children: SmallVec<[AnyElement<V>; 2]>,
92 group: Option<SharedString>,
93 base_style: StyleRefinement,
94 hover_style: StyleRefinement,
95 group_hover: Option<GroupStyle>,
96 active_style: StyleRefinement,
97 group_active: Option<GroupStyle>,
98 focus_style: StyleRefinement,
99 focus_in_style: StyleRefinement,
100 in_focus_style: StyleRefinement,
101 listeners: EventListeners<V>,
102}
103
104struct GroupStyle {
105 group: SharedString,
106 style: StyleRefinement,
107}
108
109impl<V, F> Div<V, Anonymous, F>
110where
111 F: ElementFocusability,
112 V: 'static + Send + Sync,
113{
114 pub fn id(self, id: impl Into<ElementId>) -> Div<V, Identified, F> {
115 Div {
116 identity: Identified(id.into()),
117 focusability: self.focusability,
118 children: self.children,
119 group: self.group,
120 base_style: self.base_style,
121 hover_style: self.hover_style,
122 group_hover: self.group_hover,
123 active_style: self.active_style,
124 group_active: self.group_active,
125 focus_style: self.focus_style,
126 focus_in_style: self.focus_in_style,
127 in_focus_style: self.in_focus_style,
128 listeners: self.listeners,
129 }
130 }
131}
132
133impl<V, I, F> Div<V, I, F>
134where
135 I: ElementIdentity,
136 F: ElementFocusability,
137 V: 'static + Send + Sync,
138{
139 pub fn group(mut self, group: impl Into<SharedString>) -> Self {
140 self.group = Some(group.into());
141 self
142 }
143
144 pub fn z_index(mut self, z_index: u32) -> Self {
145 self.base_style.z_index = Some(z_index);
146 self
147 }
148
149 pub fn overflow_hidden(mut self) -> Self {
150 self.base_style.overflow.x = Some(Overflow::Hidden);
151 self.base_style.overflow.y = Some(Overflow::Hidden);
152 self
153 }
154
155 pub fn overflow_hidden_x(mut self) -> Self {
156 self.base_style.overflow.x = Some(Overflow::Hidden);
157 self
158 }
159
160 pub fn overflow_hidden_y(mut self) -> Self {
161 self.base_style.overflow.y = Some(Overflow::Hidden);
162 self
163 }
164
165 pub fn overflow_scroll(mut self, _scroll_state: ScrollState) -> Self {
166 // todo!("impl scrolling")
167 // self.scroll_state = Some(scroll_state);
168 self.base_style.overflow.x = Some(Overflow::Scroll);
169 self.base_style.overflow.y = Some(Overflow::Scroll);
170 self
171 }
172
173 pub fn overflow_x_scroll(mut self, _scroll_state: ScrollState) -> Self {
174 // todo!("impl scrolling")
175 // self.scroll_state = Some(scroll_state);
176 self.base_style.overflow.x = Some(Overflow::Scroll);
177 self
178 }
179
180 pub fn overflow_y_scroll(mut self, _scroll_state: ScrollState) -> Self {
181 // todo!("impl scrolling")
182 // self.scroll_state = Some(scroll_state);
183 self.base_style.overflow.y = Some(Overflow::Scroll);
184 self
185 }
186
187 fn with_element_id<R>(
188 &mut self,
189 cx: &mut ViewContext<V>,
190 f: impl FnOnce(&mut Self, &mut ViewContext<V>) -> R,
191 ) -> R {
192 if let Some(id) = self.id() {
193 cx.with_element_id(id, |cx| f(self, cx))
194 } else {
195 f(self, cx)
196 }
197 }
198
199 pub fn compute_style(
200 &self,
201 bounds: Bounds<Pixels>,
202 state: &DivState,
203 cx: &mut ViewContext<V>,
204 ) -> Style {
205 let mut computed_style = Style::default();
206 computed_style.refine(&self.base_style);
207
208 if let Some(handle) = self.focusability.focus_handle() {
209 if handle.contains_focused(cx) {
210 computed_style.refine(&self.focus_in_style);
211 }
212
213 if handle.within_focused(cx) {
214 computed_style.refine(&self.in_focus_style);
215 }
216
217 if handle.is_focused(cx) {
218 computed_style.refine(&self.focus_style);
219 }
220 }
221
222 let mouse_position = cx.mouse_position();
223
224 if let Some(group_hover) = self.group_hover.as_ref() {
225 if let Some(group_bounds) = group_bounds(&group_hover.group, cx) {
226 if group_bounds.contains_point(&mouse_position) {
227 computed_style.refine(&group_hover.style);
228 }
229 }
230 }
231 if bounds.contains_point(&mouse_position) {
232 computed_style.refine(&self.hover_style);
233 }
234
235 let active_state = *state.active_state.lock();
236 if active_state.group {
237 if let Some(GroupStyle { style, .. }) = self.group_active.as_ref() {
238 computed_style.refine(style);
239 }
240 }
241 if active_state.element {
242 computed_style.refine(&self.active_style);
243 }
244
245 computed_style
246 }
247
248 fn paint_hover_listeners(
249 &self,
250 bounds: Bounds<Pixels>,
251 group_bounds: Option<Bounds<Pixels>>,
252 cx: &mut ViewContext<V>,
253 ) {
254 if let Some(group_bounds) = group_bounds {
255 paint_hover_listener(group_bounds, cx);
256 }
257
258 if self.hover_style.is_some() {
259 paint_hover_listener(bounds, cx);
260 }
261 }
262
263 fn paint_active_listener(
264 &self,
265 bounds: Bounds<Pixels>,
266 group_bounds: Option<Bounds<Pixels>>,
267 active_state: Arc<Mutex<ActiveState>>,
268 cx: &mut ViewContext<V>,
269 ) {
270 if active_state.lock().is_none() {
271 cx.on_mouse_event(move |_view, down: &MouseDownEvent, phase, cx| {
272 if phase == DispatchPhase::Bubble {
273 let group =
274 group_bounds.map_or(false, |bounds| bounds.contains_point(&down.position));
275 let element = bounds.contains_point(&down.position);
276 if group || element {
277 *active_state.lock() = ActiveState { group, element };
278 cx.notify();
279 }
280 }
281 });
282 } else {
283 cx.on_mouse_event(move |_, _: &MouseUpEvent, phase, cx| {
284 if phase == DispatchPhase::Capture {
285 *active_state.lock() = ActiveState::default();
286 cx.notify();
287 }
288 });
289 }
290 }
291
292 fn paint_event_listeners(
293 &mut self,
294 bounds: Bounds<Pixels>,
295 pending_click: Arc<Mutex<Option<MouseDownEvent>>>,
296 cx: &mut ViewContext<V>,
297 ) {
298 let click_listeners = mem::take(&mut self.listeners.mouse_click);
299
300 let mouse_down = pending_click.lock().clone();
301 if let Some(mouse_down) = mouse_down {
302 cx.on_mouse_event(move |state, event: &MouseUpEvent, phase, cx| {
303 if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position) {
304 let mouse_click = MouseClickEvent {
305 down: mouse_down.clone(),
306 up: event.clone(),
307 };
308 for listener in &click_listeners {
309 listener(state, &mouse_click, cx);
310 }
311 }
312
313 *pending_click.lock() = None;
314 });
315 } else {
316 cx.on_mouse_event(move |_state, event: &MouseDownEvent, phase, _cx| {
317 if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position) {
318 *pending_click.lock() = Some(event.clone());
319 }
320 });
321 }
322
323 if let Some(focus_handle) = self.focusability.focus_handle() {
324 let focus_handle = focus_handle.clone();
325 cx.on_mouse_event(move |_, event: &MouseDownEvent, phase, cx| {
326 if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position) {
327 cx.focus(&focus_handle);
328 }
329 })
330 }
331
332 for listener in mem::take(&mut self.listeners.mouse_down) {
333 cx.on_mouse_event(move |state, event: &MouseDownEvent, phase, cx| {
334 listener(state, event, &bounds, phase, cx);
335 })
336 }
337
338 for listener in mem::take(&mut self.listeners.mouse_up) {
339 cx.on_mouse_event(move |state, event: &MouseUpEvent, phase, cx| {
340 listener(state, event, &bounds, phase, cx);
341 })
342 }
343
344 for listener in mem::take(&mut self.listeners.mouse_move) {
345 cx.on_mouse_event(move |state, event: &MouseMoveEvent, phase, cx| {
346 listener(state, event, &bounds, phase, cx);
347 })
348 }
349
350 for listener in mem::take(&mut self.listeners.scroll_wheel) {
351 cx.on_mouse_event(move |state, event: &ScrollWheelEvent, phase, cx| {
352 listener(state, event, &bounds, phase, cx);
353 })
354 }
355 }
356}
357
358impl<V, I> Div<V, I, NonFocusable>
359where
360 I: ElementIdentity,
361 V: 'static + Send + Sync,
362{
363 pub fn focusable(self, handle: &FocusHandle) -> Div<V, I, Focusable> {
364 Div {
365 identity: self.identity,
366 focusability: handle.clone().into(),
367 children: self.children,
368 group: self.group,
369 base_style: self.base_style,
370 hover_style: self.hover_style,
371 group_hover: self.group_hover,
372 active_style: self.active_style,
373 group_active: self.group_active,
374 focus_style: self.focus_style,
375 focus_in_style: self.focus_in_style,
376 in_focus_style: self.in_focus_style,
377 listeners: self.listeners,
378 }
379 }
380}
381
382impl<V, I> Focus for Div<V, I, Focusable>
383where
384 I: ElementIdentity,
385 V: 'static + Send + Sync,
386{
387 fn handle(&self) -> &FocusHandle {
388 self.focusability.as_ref()
389 }
390
391 fn set_focus_style(&mut self, style: StyleRefinement) {
392 self.focus_style = style;
393 }
394
395 fn set_focus_in_style(&mut self, style: StyleRefinement) {
396 self.focus_in_style = style;
397 }
398
399 fn set_in_focus_style(&mut self, style: StyleRefinement) {
400 self.in_focus_style = style;
401 }
402}
403
404impl<V, I, F> Element for Div<V, I, F>
405where
406 I: ElementIdentity,
407 F: ElementFocusability,
408 V: 'static + Send + Sync,
409{
410 type ViewState = V;
411 type ElementState = DivState;
412
413 fn id(&self) -> Option<ElementId> {
414 self.identity.id()
415 }
416
417 fn initialize(
418 &mut self,
419 view_state: &mut Self::ViewState,
420 element_state: Option<Self::ElementState>,
421 cx: &mut ViewContext<Self::ViewState>,
422 ) -> Self::ElementState {
423 cx.with_focus(
424 self.focusability.focus_handle().cloned(),
425 mem::take(&mut self.listeners.key_down),
426 mem::take(&mut self.listeners.key_up),
427 mem::take(&mut self.listeners.focus),
428 |cx| {
429 for child in &mut self.children {
430 child.initialize(view_state, cx);
431 }
432 element_state.unwrap_or_default()
433 },
434 )
435 }
436
437 fn layout(
438 &mut self,
439 view_state: &mut Self::ViewState,
440 element_state: &mut Self::ElementState,
441 cx: &mut ViewContext<Self::ViewState>,
442 ) -> LayoutId {
443 let style = self.compute_style(Bounds::default(), element_state, cx);
444 style.apply_text_style(cx, |cx| {
445 self.with_element_id(cx, |this, cx| {
446 let layout_ids = this
447 .children
448 .iter_mut()
449 .map(|child| child.layout(view_state, cx))
450 .collect::<Vec<_>>();
451 cx.request_layout(&style, layout_ids)
452 })
453 })
454 }
455
456 fn paint(
457 &mut self,
458 bounds: Bounds<Pixels>,
459 view_state: &mut Self::ViewState,
460 element_state: &mut Self::ElementState,
461 cx: &mut ViewContext<Self::ViewState>,
462 ) {
463 self.with_element_id(cx, |this, cx| {
464 if let Some(group) = this.group.clone() {
465 cx.default_global::<GroupBounds>()
466 .0
467 .entry(group)
468 .or_default()
469 .push(bounds);
470 }
471
472 let hover_group_bounds = this
473 .group_hover
474 .as_ref()
475 .and_then(|group_hover| group_bounds(&group_hover.group, cx));
476 let active_group_bounds = this
477 .group_active
478 .as_ref()
479 .and_then(|group_active| group_bounds(&group_active.group, cx));
480 let style = this.compute_style(bounds, element_state, cx);
481 let z_index = style.z_index.unwrap_or(0);
482
483 // Paint background and event handlers.
484 cx.stack(z_index, |cx| {
485 cx.stack(0, |cx| {
486 style.paint(bounds, cx);
487 this.paint_hover_listeners(bounds, hover_group_bounds, cx);
488 this.paint_active_listener(
489 bounds,
490 active_group_bounds,
491 element_state.active_state.clone(),
492 cx,
493 );
494 this.paint_event_listeners(bounds, element_state.pending_click.clone(), cx);
495 });
496
497 cx.stack(1, |cx| {
498 style.apply_text_style(cx, |cx| {
499 style.apply_overflow(bounds, cx, |cx| {
500 for child in &mut this.children {
501 child.paint(view_state, None, cx);
502 }
503 })
504 })
505 });
506 });
507
508 if let Some(group) = this.group.as_ref() {
509 cx.default_global::<GroupBounds>()
510 .0
511 .get_mut(group)
512 .unwrap()
513 .pop();
514 }
515 })
516 }
517}
518
519impl<V, I, F> IntoAnyElement<V> for Div<V, I, F>
520where
521 I: ElementIdentity,
522 F: ElementFocusability,
523 V: 'static + Send + Sync,
524{
525 fn into_any(self) -> AnyElement<V> {
526 AnyElement::new(self)
527 }
528}
529
530impl<V, I, F> ParentElement for Div<V, I, F>
531where
532 I: ElementIdentity,
533 F: ElementFocusability,
534 V: 'static + Send + Sync,
535{
536 fn children_mut(&mut self) -> &mut SmallVec<[AnyElement<Self::ViewState>; 2]> {
537 &mut self.children
538 }
539}
540
541impl<V, I, F> Styled for Div<V, I, F>
542where
543 I: ElementIdentity,
544 F: ElementFocusability,
545 V: 'static + Send + Sync,
546{
547 fn style(&mut self) -> &mut StyleRefinement {
548 &mut self.base_style
549 }
550}
551
552impl<V, I, F> Interactive for Div<V, I, F>
553where
554 I: ElementIdentity,
555 F: ElementFocusability,
556 V: 'static + Send + Sync,
557{
558 fn listeners(&mut self) -> &mut EventListeners<V> {
559 &mut self.listeners
560 }
561}
562
563impl<V, I, F> Hover for Div<V, I, F>
564where
565 I: ElementIdentity,
566 F: ElementFocusability,
567 V: 'static + Send + Sync,
568{
569 fn set_hover_style(&mut self, group: Option<SharedString>, style: StyleRefinement) {
570 if let Some(group) = group {
571 self.group_hover = Some(GroupStyle { group, style });
572 } else {
573 self.hover_style = style;
574 }
575 }
576}
577
578impl<V, F> Click for Div<V, Identified, F>
579where
580 F: ElementFocusability,
581 V: 'static + Send + Sync,
582{
583}
584
585impl<V, F> Active for Div<V, Identified, F>
586where
587 F: ElementFocusability,
588 V: 'static + Send + Sync,
589{
590 fn set_active_style(&mut self, group: Option<SharedString>, style: StyleRefinement) {
591 if let Some(group) = group {
592 self.group_active = Some(GroupStyle { group, style });
593 } else {
594 self.active_style = style;
595 }
596 }
597}
598
599fn paint_hover_listener<V>(bounds: Bounds<Pixels>, cx: &mut ViewContext<V>)
600where
601 V: 'static + Send + Sync,
602{
603 let hovered = bounds.contains_point(&cx.mouse_position());
604 cx.on_mouse_event(move |_, event: &MouseMoveEvent, phase, cx| {
605 if phase == DispatchPhase::Capture {
606 if bounds.contains_point(&event.position) != hovered {
607 cx.notify();
608 }
609 }
610 });
611}