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 let mouse_down = pending_click.lock().clone();
300 if let Some(mouse_down) = mouse_down {
301 cx.on_mouse_event(move |state, event: &MouseUpEvent, phase, cx| {
302 if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position) {
303 let mouse_click = MouseClickEvent {
304 down: mouse_down.clone(),
305 up: event.clone(),
306 };
307 for listener in &click_listeners {
308 listener(state, &mouse_click, cx);
309 }
310 }
311
312 *pending_click.lock() = None;
313 });
314 } else {
315 cx.on_mouse_event(move |_state, event: &MouseDownEvent, phase, _cx| {
316 if phase == DispatchPhase::Bubble && bounds.contains_point(&event.position) {
317 *pending_click.lock() = Some(event.clone());
318 }
319 });
320 }
321
322 for listener in mem::take(&mut self.listeners.mouse_down) {
323 cx.on_mouse_event(move |state, event: &MouseDownEvent, phase, cx| {
324 listener(state, event, &bounds, phase, cx);
325 })
326 }
327
328 for listener in mem::take(&mut self.listeners.mouse_up) {
329 cx.on_mouse_event(move |state, event: &MouseUpEvent, phase, cx| {
330 listener(state, event, &bounds, phase, cx);
331 })
332 }
333
334 for listener in mem::take(&mut self.listeners.mouse_move) {
335 cx.on_mouse_event(move |state, event: &MouseMoveEvent, phase, cx| {
336 listener(state, event, &bounds, phase, cx);
337 })
338 }
339
340 for listener in mem::take(&mut self.listeners.scroll_wheel) {
341 cx.on_mouse_event(move |state, event: &ScrollWheelEvent, phase, cx| {
342 listener(state, event, &bounds, phase, cx);
343 })
344 }
345 }
346}
347
348impl<V, I> Div<V, I, NonFocusable>
349where
350 I: ElementIdentity,
351 V: 'static + Send + Sync,
352{
353 pub fn focusable(self, handle: &FocusHandle) -> Div<V, I, Focusable> {
354 Div {
355 identity: self.identity,
356 focusability: handle.clone().into(),
357 children: self.children,
358 group: self.group,
359 base_style: self.base_style,
360 hover_style: self.hover_style,
361 group_hover: self.group_hover,
362 active_style: self.active_style,
363 group_active: self.group_active,
364 focus_style: self.focus_style,
365 focus_in_style: self.focus_in_style,
366 in_focus_style: self.in_focus_style,
367 listeners: self.listeners,
368 }
369 }
370}
371
372impl<V, I> Focus for Div<V, I, Focusable>
373where
374 I: ElementIdentity,
375 V: 'static + Send + Sync,
376{
377 fn handle(&self) -> &FocusHandle {
378 self.focusability.as_ref()
379 }
380
381 fn set_focus_style(&mut self, style: StyleRefinement) {
382 self.focus_style = style;
383 }
384
385 fn set_focus_in_style(&mut self, style: StyleRefinement) {
386 self.focus_in_style = style;
387 }
388
389 fn set_in_focus_style(&mut self, style: StyleRefinement) {
390 self.in_focus_style = style;
391 }
392}
393
394impl<V, I, F> Element for Div<V, I, F>
395where
396 I: ElementIdentity,
397 F: ElementFocusability,
398 V: 'static + Send + Sync,
399{
400 type ViewState = V;
401 type ElementState = DivState;
402
403 fn id(&self) -> Option<ElementId> {
404 self.identity.id()
405 }
406
407 fn initialize(
408 &mut self,
409 view_state: &mut Self::ViewState,
410 element_state: Option<Self::ElementState>,
411 cx: &mut ViewContext<Self::ViewState>,
412 ) -> Self::ElementState {
413 cx.with_focus(
414 self.focusability.focus_handle().cloned(),
415 mem::take(&mut self.listeners.key_down),
416 mem::take(&mut self.listeners.key_up),
417 mem::take(&mut self.listeners.focus),
418 |cx| {
419 for child in &mut self.children {
420 child.initialize(view_state, cx);
421 }
422 element_state.unwrap_or_default()
423 },
424 )
425 }
426
427 fn layout(
428 &mut self,
429 view_state: &mut Self::ViewState,
430 element_state: &mut Self::ElementState,
431 cx: &mut ViewContext<Self::ViewState>,
432 ) -> LayoutId {
433 let style = self.compute_style(Bounds::default(), element_state, cx);
434 style.apply_text_style(cx, |cx| {
435 self.with_element_id(cx, |this, cx| {
436 let layout_ids = this
437 .children
438 .iter_mut()
439 .map(|child| child.layout(view_state, cx))
440 .collect::<Vec<_>>();
441 cx.request_layout(&style, layout_ids)
442 })
443 })
444 }
445
446 fn paint(
447 &mut self,
448 bounds: Bounds<Pixels>,
449 view_state: &mut Self::ViewState,
450 element_state: &mut Self::ElementState,
451 cx: &mut ViewContext<Self::ViewState>,
452 ) {
453 self.with_element_id(cx, |this, cx| {
454 if let Some(group) = this.group.clone() {
455 cx.default_global::<GroupBounds>()
456 .0
457 .entry(group)
458 .or_default()
459 .push(bounds);
460 }
461
462 let hover_group_bounds = this
463 .group_hover
464 .as_ref()
465 .and_then(|group_hover| group_bounds(&group_hover.group, cx));
466 let active_group_bounds = this
467 .group_active
468 .as_ref()
469 .and_then(|group_active| group_bounds(&group_active.group, cx));
470 let style = this.compute_style(bounds, element_state, cx);
471 let z_index = style.z_index.unwrap_or(0);
472
473 // Paint background and event handlers.
474 cx.stack(z_index, |cx| {
475 cx.stack(0, |cx| {
476 style.paint(bounds, cx);
477 this.paint_hover_listeners(bounds, hover_group_bounds, cx);
478 this.paint_active_listener(
479 bounds,
480 active_group_bounds,
481 element_state.active_state.clone(),
482 cx,
483 );
484 this.paint_event_listeners(bounds, element_state.pending_click.clone(), cx);
485 });
486
487 cx.stack(1, |cx| {
488 style.apply_text_style(cx, |cx| {
489 style.apply_overflow(bounds, cx, |cx| {
490 for child in &mut this.children {
491 child.paint(view_state, None, cx);
492 }
493 })
494 })
495 });
496 });
497
498 if let Some(group) = this.group.as_ref() {
499 cx.default_global::<GroupBounds>()
500 .0
501 .get_mut(group)
502 .unwrap()
503 .pop();
504 }
505 })
506 }
507}
508
509impl<V, I, F> IntoAnyElement<V> for Div<V, I, F>
510where
511 I: ElementIdentity,
512 F: ElementFocusability,
513 V: 'static + Send + Sync,
514{
515 fn into_any(self) -> AnyElement<V> {
516 AnyElement::new(self)
517 }
518}
519
520impl<V, I, F> ParentElement for Div<V, I, F>
521where
522 I: ElementIdentity,
523 F: ElementFocusability,
524 V: 'static + Send + Sync,
525{
526 fn children_mut(&mut self) -> &mut SmallVec<[AnyElement<Self::ViewState>; 2]> {
527 &mut self.children
528 }
529}
530
531impl<V, I, F> Styled for Div<V, I, F>
532where
533 I: ElementIdentity,
534 F: ElementFocusability,
535 V: 'static + Send + Sync,
536{
537 fn style(&mut self) -> &mut StyleRefinement {
538 &mut self.base_style
539 }
540}
541
542impl<V, I, F> Interactive for Div<V, I, F>
543where
544 I: ElementIdentity,
545 F: ElementFocusability,
546 V: 'static + Send + Sync,
547{
548 fn listeners(&mut self) -> &mut EventListeners<V> {
549 &mut self.listeners
550 }
551}
552
553impl<V, I, F> Hover for Div<V, I, F>
554where
555 I: ElementIdentity,
556 F: ElementFocusability,
557 V: 'static + Send + Sync,
558{
559 fn set_hover_style(&mut self, group: Option<SharedString>, style: StyleRefinement) {
560 if let Some(group) = group {
561 self.group_hover = Some(GroupStyle { group, style });
562 } else {
563 self.hover_style = style;
564 }
565 }
566}
567
568impl<V, F> Click for Div<V, Identified, F>
569where
570 F: ElementFocusability,
571 V: 'static + Send + Sync,
572{
573}
574
575impl<V, F> Active for Div<V, Identified, F>
576where
577 F: ElementFocusability,
578 V: 'static + Send + Sync,
579{
580 fn set_active_style(&mut self, group: Option<SharedString>, style: StyleRefinement) {
581 if let Some(group) = group {
582 self.group_active = Some(GroupStyle { group, style });
583 } else {
584 self.active_style = style;
585 }
586 }
587}
588
589fn paint_hover_listener<V>(bounds: Bounds<Pixels>, cx: &mut ViewContext<V>)
590where
591 V: 'static + Send + Sync,
592{
593 let hovered = bounds.contains_point(&cx.mouse_position());
594 cx.on_mouse_event(move |_, event: &MouseMoveEvent, phase, cx| {
595 if phase == DispatchPhase::Capture {
596 if bounds.contains_point(&event.position) != hovered {
597 cx.notify();
598 }
599 }
600 });
601}