1use crate::{
2 app::{AppContext, MutableAppContext, WindowInvalidation},
3 elements::Element,
4 font_cache::FontCache,
5 geometry::rect::RectF,
6 json::{self, ToJson},
7 keymap::Keystroke,
8 platform::{CursorStyle, Event},
9 scene::CursorRegion,
10 text_layout::TextLayoutCache,
11 Action, AnyModelHandle, AnyViewHandle, AnyWeakModelHandle, AssetCache, ElementBox, Entity,
12 FontSystem, ModelHandle, MouseRegion, MouseRegionId, ReadModel, ReadView, RenderContext,
13 RenderParams, Scene, UpgradeModelHandle, UpgradeViewHandle, View, ViewHandle, WeakModelHandle,
14 WeakViewHandle,
15};
16use pathfinder_geometry::vector::{vec2f, Vector2F};
17use serde_json::json;
18use smallvec::SmallVec;
19use std::{
20 collections::{HashMap, HashSet},
21 marker::PhantomData,
22 ops::{Deref, DerefMut},
23 sync::Arc,
24};
25
26pub struct Presenter {
27 window_id: usize,
28 pub(crate) rendered_views: HashMap<usize, ElementBox>,
29 parents: HashMap<usize, usize>,
30 cursor_regions: Vec<CursorRegion>,
31 mouse_regions: Vec<(MouseRegion, usize)>,
32 font_cache: Arc<FontCache>,
33 text_layout_cache: TextLayoutCache,
34 asset_cache: Arc<AssetCache>,
35 last_mouse_moved_event: Option<Event>,
36 hovered_region_ids: HashSet<MouseRegionId>,
37 clicked_region: Option<MouseRegion>,
38 right_clicked_region: Option<MouseRegion>,
39 prev_drag_position: Option<Vector2F>,
40 titlebar_height: f32,
41}
42
43impl Presenter {
44 pub fn new(
45 window_id: usize,
46 titlebar_height: f32,
47 font_cache: Arc<FontCache>,
48 text_layout_cache: TextLayoutCache,
49 asset_cache: Arc<AssetCache>,
50 cx: &mut MutableAppContext,
51 ) -> Self {
52 Self {
53 window_id,
54 rendered_views: cx.render_views(window_id, titlebar_height),
55 parents: HashMap::new(),
56 cursor_regions: Default::default(),
57 mouse_regions: Default::default(),
58 font_cache,
59 text_layout_cache,
60 asset_cache,
61 last_mouse_moved_event: None,
62 hovered_region_ids: Default::default(),
63 clicked_region: None,
64 right_clicked_region: None,
65 prev_drag_position: None,
66 titlebar_height,
67 }
68 }
69
70 pub fn dispatch_path(&self, app: &AppContext) -> Vec<usize> {
71 let mut path = Vec::new();
72 if let Some(view_id) = app.focused_view_id(self.window_id) {
73 self.compute_dispatch_path_from(view_id, &mut path)
74 }
75 path
76 }
77
78 pub(crate) fn compute_dispatch_path_from(&self, mut view_id: usize, path: &mut Vec<usize>) {
79 path.push(view_id);
80 while let Some(parent_id) = self.parents.get(&view_id).copied() {
81 path.push(parent_id);
82 view_id = parent_id;
83 }
84 path.reverse();
85 }
86
87 pub fn invalidate(
88 &mut self,
89 invalidation: &mut WindowInvalidation,
90 cx: &mut MutableAppContext,
91 ) {
92 cx.start_frame();
93 for view_id in &invalidation.removed {
94 invalidation.updated.remove(&view_id);
95 self.rendered_views.remove(&view_id);
96 self.parents.remove(&view_id);
97 }
98 for view_id in &invalidation.updated {
99 self.rendered_views.insert(
100 *view_id,
101 cx.render_view(RenderParams {
102 window_id: self.window_id,
103 view_id: *view_id,
104 titlebar_height: self.titlebar_height,
105 hovered_region_ids: self.hovered_region_ids.clone(),
106 clicked_region_id: self.clicked_region.as_ref().and_then(MouseRegion::id),
107 right_clicked_region_id: self
108 .right_clicked_region
109 .as_ref()
110 .and_then(MouseRegion::id),
111 refreshing: false,
112 })
113 .unwrap(),
114 );
115 }
116 }
117
118 pub fn refresh(&mut self, invalidation: &mut WindowInvalidation, cx: &mut MutableAppContext) {
119 self.invalidate(invalidation, cx);
120 for (view_id, view) in &mut self.rendered_views {
121 if !invalidation.updated.contains(view_id) {
122 *view = cx
123 .render_view(RenderParams {
124 window_id: self.window_id,
125 view_id: *view_id,
126 titlebar_height: self.titlebar_height,
127 hovered_region_ids: self.hovered_region_ids.clone(),
128 clicked_region_id: self.clicked_region.as_ref().and_then(MouseRegion::id),
129 right_clicked_region_id: self
130 .right_clicked_region
131 .as_ref()
132 .and_then(MouseRegion::id),
133 refreshing: true,
134 })
135 .unwrap();
136 }
137 }
138 }
139
140 pub fn build_scene(
141 &mut self,
142 window_size: Vector2F,
143 scale_factor: f32,
144 refreshing: bool,
145 cx: &mut MutableAppContext,
146 ) -> Scene {
147 let mut scene = Scene::new(scale_factor);
148
149 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
150 self.layout(window_size, refreshing, cx);
151 let mut paint_cx = self.build_paint_context(&mut scene, window_size, cx);
152 paint_cx.paint(
153 root_view_id,
154 Vector2F::zero(),
155 RectF::new(Vector2F::zero(), window_size),
156 );
157 self.text_layout_cache.finish_frame();
158 self.cursor_regions = scene.cursor_regions();
159 self.mouse_regions = scene.mouse_regions();
160
161 if cx.window_is_active(self.window_id) {
162 if let Some(event) = self.last_mouse_moved_event.clone() {
163 let mut invalidated_views = Vec::new();
164 self.handle_hover_events(&event, &mut invalidated_views, cx);
165
166 for view_id in invalidated_views {
167 cx.notify_view(self.window_id, view_id);
168 }
169 }
170 }
171 } else {
172 log::error!("could not find root_view_id for window {}", self.window_id);
173 }
174
175 scene
176 }
177
178 fn layout(&mut self, window_size: Vector2F, refreshing: bool, cx: &mut MutableAppContext) {
179 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
180 self.build_layout_context(window_size, refreshing, cx)
181 .layout(root_view_id, SizeConstraint::strict(window_size));
182 }
183 }
184
185 pub fn build_layout_context<'a>(
186 &'a mut self,
187 window_size: Vector2F,
188 refreshing: bool,
189 cx: &'a mut MutableAppContext,
190 ) -> LayoutContext<'a> {
191 LayoutContext {
192 window_id: self.window_id,
193 rendered_views: &mut self.rendered_views,
194 parents: &mut self.parents,
195 font_cache: &self.font_cache,
196 font_system: cx.platform().fonts(),
197 text_layout_cache: &self.text_layout_cache,
198 asset_cache: &self.asset_cache,
199 view_stack: Vec::new(),
200 refreshing,
201 hovered_region_ids: self.hovered_region_ids.clone(),
202 clicked_region_id: self.clicked_region.as_ref().and_then(MouseRegion::id),
203 right_clicked_region_id: self.right_clicked_region.as_ref().and_then(MouseRegion::id),
204 titlebar_height: self.titlebar_height,
205 window_size,
206 app: cx,
207 }
208 }
209
210 pub fn build_paint_context<'a>(
211 &'a mut self,
212 scene: &'a mut Scene,
213 window_size: Vector2F,
214 cx: &'a mut MutableAppContext,
215 ) -> PaintContext {
216 PaintContext {
217 scene,
218 window_size,
219 font_cache: &self.font_cache,
220 text_layout_cache: &self.text_layout_cache,
221 rendered_views: &mut self.rendered_views,
222 view_stack: Vec::new(),
223 app: cx,
224 }
225 }
226
227 pub fn dispatch_event(&mut self, event: Event, cx: &mut MutableAppContext) -> bool {
228 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
229 let mut invalidated_views = Vec::new();
230 let mut mouse_down_out_handlers = Vec::new();
231 let mut mouse_down_region = None;
232 let mut clicked_region = None;
233 let mut right_mouse_down_region = None;
234 let mut right_clicked_region = None;
235 let mut dragged_region = None;
236
237 match event {
238 Event::LeftMouseDown { position, .. } => {
239 let mut hit = false;
240 for (region, _) in self.mouse_regions.iter().rev() {
241 if region.bounds.contains_point(position) {
242 if !hit {
243 hit = true;
244 invalidated_views.push(region.view_id);
245 mouse_down_region = Some((region.clone(), position));
246 self.clicked_region = Some(region.clone());
247 self.prev_drag_position = Some(position);
248 }
249 } else if let Some(handler) = region.mouse_down_out.clone() {
250 mouse_down_out_handlers.push((handler, region.view_id, position));
251 }
252 }
253 }
254 Event::LeftMouseUp {
255 position,
256 click_count,
257 ..
258 } => {
259 self.prev_drag_position.take();
260 if let Some(region) = self.clicked_region.take() {
261 invalidated_views.push(region.view_id);
262 if region.bounds.contains_point(position) {
263 clicked_region = Some((region, position, click_count));
264 }
265 }
266 }
267 Event::RightMouseDown { position, .. } => {
268 let mut hit = false;
269 for (region, _) in self.mouse_regions.iter().rev() {
270 if region.bounds.contains_point(position) {
271 if !hit {
272 hit = true;
273 invalidated_views.push(region.view_id);
274 right_mouse_down_region = Some((region.clone(), position));
275 self.right_clicked_region = Some(region.clone());
276 }
277 } else if let Some(handler) = region.right_mouse_down_out.clone() {
278 mouse_down_out_handlers.push((handler, region.view_id, position));
279 }
280 }
281 }
282 Event::RightMouseUp {
283 position,
284 click_count,
285 ..
286 } => {
287 if let Some(region) = self.right_clicked_region.take() {
288 invalidated_views.push(region.view_id);
289 if region.bounds.contains_point(position) {
290 right_clicked_region = Some((region, position, click_count));
291 }
292 }
293 }
294 Event::MouseMoved { .. } => {
295 self.last_mouse_moved_event = Some(event.clone());
296 }
297 Event::LeftMouseDragged {
298 position,
299 shift,
300 ctrl,
301 alt,
302 cmd,
303 } => {
304 if let Some((clicked_region, prev_drag_position)) = self
305 .clicked_region
306 .as_ref()
307 .zip(self.prev_drag_position.as_mut())
308 {
309 dragged_region =
310 Some((clicked_region.clone(), *prev_drag_position, position));
311 *prev_drag_position = position;
312 }
313
314 self.last_mouse_moved_event = Some(Event::MouseMoved {
315 position,
316 left_mouse_down: true,
317 shift,
318 ctrl,
319 alt,
320 cmd,
321 });
322 }
323 _ => {}
324 }
325
326 let (mut handled, mut event_cx) =
327 self.handle_hover_events(&event, &mut invalidated_views, cx);
328
329 for (handler, view_id, position) in mouse_down_out_handlers {
330 event_cx.with_current_view(view_id, |event_cx| handler(position, event_cx))
331 }
332
333 if let Some((mouse_down_region, position)) = mouse_down_region {
334 handled = true;
335 if let Some(mouse_down_callback) = mouse_down_region.mouse_down {
336 event_cx.with_current_view(mouse_down_region.view_id, |event_cx| {
337 mouse_down_callback(position, event_cx);
338 })
339 }
340 }
341
342 if let Some((clicked_region, position, click_count)) = clicked_region {
343 handled = true;
344 if let Some(click_callback) = clicked_region.click {
345 event_cx.with_current_view(clicked_region.view_id, |event_cx| {
346 click_callback(position, click_count, event_cx);
347 })
348 }
349 }
350
351 if let Some((right_mouse_down_region, position)) = right_mouse_down_region {
352 handled = true;
353 if let Some(right_mouse_down_callback) = right_mouse_down_region.right_mouse_down {
354 event_cx.with_current_view(right_mouse_down_region.view_id, |event_cx| {
355 right_mouse_down_callback(position, event_cx);
356 })
357 }
358 }
359
360 if let Some((right_clicked_region, position, click_count)) = right_clicked_region {
361 handled = true;
362 if let Some(right_click_callback) = right_clicked_region.right_click {
363 event_cx.with_current_view(right_clicked_region.view_id, |event_cx| {
364 right_click_callback(position, click_count, event_cx);
365 })
366 }
367 }
368
369 if let Some((dragged_region, prev_position, position)) = dragged_region {
370 handled = true;
371 if let Some(drag_callback) = dragged_region.drag {
372 event_cx.with_current_view(dragged_region.view_id, |event_cx| {
373 drag_callback(prev_position, position, event_cx);
374 })
375 }
376 }
377
378 if !handled {
379 handled = event_cx.dispatch_event(root_view_id, &event);
380 }
381
382 invalidated_views.extend(event_cx.invalidated_views);
383 let dispatch_directives = event_cx.dispatched_actions;
384
385 for view_id in invalidated_views {
386 cx.notify_view(self.window_id, view_id);
387 }
388
389 let mut dispatch_path = Vec::new();
390 for directive in dispatch_directives {
391 dispatch_path.clear();
392 if let Some(view_id) = directive.dispatcher_view_id {
393 self.compute_dispatch_path_from(view_id, &mut dispatch_path);
394 }
395 cx.dispatch_action_any(self.window_id, &dispatch_path, directive.action.as_ref());
396 }
397
398 handled
399 } else {
400 false
401 }
402 }
403
404 fn handle_hover_events<'a>(
405 &'a mut self,
406 event: &Event,
407 invalidated_views: &mut Vec<usize>,
408 cx: &'a mut MutableAppContext,
409 ) -> (bool, EventContext<'a>) {
410 let mut unhovered_regions = Vec::new();
411 let mut hovered_regions = Vec::new();
412
413 if let Event::MouseMoved {
414 position,
415 left_mouse_down,
416 ..
417 } = event
418 {
419 if !left_mouse_down {
420 let mut style_to_assign = CursorStyle::Arrow;
421 for region in self.cursor_regions.iter().rev() {
422 if region.bounds.contains_point(*position) {
423 style_to_assign = region.style;
424 break;
425 }
426 }
427 cx.platform().set_cursor_style(style_to_assign);
428
429 let mut hover_depth = None;
430 for (region, depth) in self.mouse_regions.iter().rev() {
431 if region.bounds.contains_point(*position)
432 && hover_depth.map_or(true, |hover_depth| hover_depth == *depth)
433 {
434 hover_depth = Some(*depth);
435 if let Some(region_id) = region.id() {
436 if !self.hovered_region_ids.contains(®ion_id) {
437 invalidated_views.push(region.view_id);
438 hovered_regions.push((region.clone(), position));
439 self.hovered_region_ids.insert(region_id);
440 }
441 }
442 } else {
443 if let Some(region_id) = region.id() {
444 if self.hovered_region_ids.contains(®ion_id) {
445 invalidated_views.push(region.view_id);
446 unhovered_regions.push((region.clone(), position));
447 self.hovered_region_ids.remove(®ion_id);
448 }
449 }
450 }
451 }
452 }
453 }
454
455 let mut event_cx = self.build_event_context(cx);
456 let mut handled = false;
457
458 for (unhovered_region, position) in unhovered_regions {
459 handled = true;
460 if let Some(hover_callback) = unhovered_region.hover {
461 event_cx.with_current_view(unhovered_region.view_id, |event_cx| {
462 hover_callback(*position, false, event_cx);
463 })
464 }
465 }
466
467 for (hovered_region, position) in hovered_regions {
468 handled = true;
469 if let Some(hover_callback) = hovered_region.hover {
470 event_cx.with_current_view(hovered_region.view_id, |event_cx| {
471 hover_callback(*position, true, event_cx);
472 })
473 }
474 }
475
476 (handled, event_cx)
477 }
478
479 pub fn build_event_context<'a>(
480 &'a mut self,
481 cx: &'a mut MutableAppContext,
482 ) -> EventContext<'a> {
483 EventContext {
484 rendered_views: &mut self.rendered_views,
485 dispatched_actions: Default::default(),
486 font_cache: &self.font_cache,
487 text_layout_cache: &self.text_layout_cache,
488 view_stack: Default::default(),
489 invalidated_views: Default::default(),
490 notify_count: 0,
491 window_id: self.window_id,
492 app: cx,
493 }
494 }
495
496 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
497 let view = cx.root_view(self.window_id)?;
498 Some(json!({
499 "root_view": view.debug_json(cx),
500 "root_element": self.rendered_views.get(&view.id())
501 .map(|root_element| {
502 root_element.debug(&DebugContext {
503 rendered_views: &self.rendered_views,
504 font_cache: &self.font_cache,
505 app: cx,
506 })
507 })
508 }))
509 }
510}
511
512pub struct DispatchDirective {
513 pub dispatcher_view_id: Option<usize>,
514 pub action: Box<dyn Action>,
515}
516
517pub struct LayoutContext<'a> {
518 window_id: usize,
519 rendered_views: &'a mut HashMap<usize, ElementBox>,
520 parents: &'a mut HashMap<usize, usize>,
521 view_stack: Vec<usize>,
522 pub font_cache: &'a Arc<FontCache>,
523 pub font_system: Arc<dyn FontSystem>,
524 pub text_layout_cache: &'a TextLayoutCache,
525 pub asset_cache: &'a AssetCache,
526 pub app: &'a mut MutableAppContext,
527 pub refreshing: bool,
528 pub window_size: Vector2F,
529 titlebar_height: f32,
530 hovered_region_ids: HashSet<MouseRegionId>,
531 clicked_region_id: Option<MouseRegionId>,
532 right_clicked_region_id: Option<MouseRegionId>,
533}
534
535impl<'a> LayoutContext<'a> {
536 pub(crate) fn keystrokes_for_action(
537 &self,
538 action: &dyn Action,
539 ) -> Option<SmallVec<[Keystroke; 2]>> {
540 self.app
541 .keystrokes_for_action(self.window_id, &self.view_stack, action)
542 }
543
544 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
545 if let Some(parent_id) = self.view_stack.last() {
546 self.parents.insert(view_id, *parent_id);
547 }
548 self.view_stack.push(view_id);
549 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
550 let size = rendered_view.layout(constraint, self);
551 self.rendered_views.insert(view_id, rendered_view);
552 self.view_stack.pop();
553 size
554 }
555
556 pub fn render<F, V, T>(&mut self, handle: &ViewHandle<V>, f: F) -> T
557 where
558 F: FnOnce(&mut V, &mut RenderContext<V>) -> T,
559 V: View,
560 {
561 handle.update(self.app, |view, cx| {
562 let mut render_cx = RenderContext {
563 app: cx,
564 window_id: handle.window_id(),
565 view_id: handle.id(),
566 view_type: PhantomData,
567 titlebar_height: self.titlebar_height,
568 hovered_region_ids: self.hovered_region_ids.clone(),
569 clicked_region_id: self.clicked_region_id,
570 right_clicked_region_id: self.right_clicked_region_id,
571 refreshing: self.refreshing,
572 };
573 f(view, &mut render_cx)
574 })
575 }
576}
577
578impl<'a> Deref for LayoutContext<'a> {
579 type Target = MutableAppContext;
580
581 fn deref(&self) -> &Self::Target {
582 self.app
583 }
584}
585
586impl<'a> DerefMut for LayoutContext<'a> {
587 fn deref_mut(&mut self) -> &mut Self::Target {
588 self.app
589 }
590}
591
592impl<'a> ReadView for LayoutContext<'a> {
593 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
594 self.app.read_view(handle)
595 }
596}
597
598impl<'a> ReadModel for LayoutContext<'a> {
599 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
600 self.app.read_model(handle)
601 }
602}
603
604impl<'a> UpgradeModelHandle for LayoutContext<'a> {
605 fn upgrade_model_handle<T: Entity>(
606 &self,
607 handle: &WeakModelHandle<T>,
608 ) -> Option<ModelHandle<T>> {
609 self.app.upgrade_model_handle(handle)
610 }
611
612 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
613 self.app.model_handle_is_upgradable(handle)
614 }
615
616 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
617 self.app.upgrade_any_model_handle(handle)
618 }
619}
620
621impl<'a> UpgradeViewHandle for LayoutContext<'a> {
622 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
623 self.app.upgrade_view_handle(handle)
624 }
625
626 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
627 self.app.upgrade_any_view_handle(handle)
628 }
629}
630
631pub struct PaintContext<'a> {
632 rendered_views: &'a mut HashMap<usize, ElementBox>,
633 view_stack: Vec<usize>,
634 pub window_size: Vector2F,
635 pub scene: &'a mut Scene,
636 pub font_cache: &'a FontCache,
637 pub text_layout_cache: &'a TextLayoutCache,
638 pub app: &'a AppContext,
639}
640
641impl<'a> PaintContext<'a> {
642 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
643 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
644 self.view_stack.push(view_id);
645 tree.paint(origin, visible_bounds, self);
646 self.rendered_views.insert(view_id, tree);
647 self.view_stack.pop();
648 }
649 }
650
651 #[inline]
652 pub fn paint_layer<F>(&mut self, clip_bounds: Option<RectF>, f: F)
653 where
654 F: FnOnce(&mut Self) -> (),
655 {
656 self.scene.push_layer(clip_bounds);
657 f(self);
658 self.scene.pop_layer();
659 }
660
661 pub fn current_view_id(&self) -> usize {
662 *self.view_stack.last().unwrap()
663 }
664}
665
666impl<'a> Deref for PaintContext<'a> {
667 type Target = AppContext;
668
669 fn deref(&self) -> &Self::Target {
670 self.app
671 }
672}
673
674pub struct EventContext<'a> {
675 rendered_views: &'a mut HashMap<usize, ElementBox>,
676 dispatched_actions: Vec<DispatchDirective>,
677 pub font_cache: &'a FontCache,
678 pub text_layout_cache: &'a TextLayoutCache,
679 pub app: &'a mut MutableAppContext,
680 pub window_id: usize,
681 pub notify_count: usize,
682 view_stack: Vec<usize>,
683 invalidated_views: HashSet<usize>,
684}
685
686impl<'a> EventContext<'a> {
687 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
688 if let Some(mut element) = self.rendered_views.remove(&view_id) {
689 let result =
690 self.with_current_view(view_id, |this| element.dispatch_event(event, this));
691 self.rendered_views.insert(view_id, element);
692 result
693 } else {
694 false
695 }
696 }
697
698 fn with_current_view<F, T>(&mut self, view_id: usize, f: F) -> T
699 where
700 F: FnOnce(&mut Self) -> T,
701 {
702 self.view_stack.push(view_id);
703 let result = f(self);
704 self.view_stack.pop();
705 result
706 }
707
708 pub fn window_id(&self) -> usize {
709 self.window_id
710 }
711
712 pub fn view_id(&self) -> Option<usize> {
713 self.view_stack.last().copied()
714 }
715
716 pub fn is_parent_view_focused(&self) -> bool {
717 if let Some(parent_view_id) = self.view_stack.last() {
718 self.app.focused_view_id(self.window_id) == Some(*parent_view_id)
719 } else {
720 false
721 }
722 }
723
724 pub fn focus_parent_view(&mut self) {
725 if let Some(parent_view_id) = self.view_stack.last() {
726 self.app.focus(self.window_id, Some(*parent_view_id))
727 }
728 }
729
730 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
731 self.dispatched_actions.push(DispatchDirective {
732 dispatcher_view_id: self.view_stack.last().copied(),
733 action,
734 });
735 }
736
737 pub fn dispatch_action<A: Action>(&mut self, action: A) {
738 self.dispatch_any_action(Box::new(action));
739 }
740
741 pub fn notify(&mut self) {
742 self.notify_count += 1;
743 if let Some(view_id) = self.view_stack.last() {
744 self.invalidated_views.insert(*view_id);
745 }
746 }
747
748 pub fn notify_count(&self) -> usize {
749 self.notify_count
750 }
751}
752
753impl<'a> Deref for EventContext<'a> {
754 type Target = MutableAppContext;
755
756 fn deref(&self) -> &Self::Target {
757 self.app
758 }
759}
760
761impl<'a> DerefMut for EventContext<'a> {
762 fn deref_mut(&mut self) -> &mut Self::Target {
763 self.app
764 }
765}
766
767pub struct DebugContext<'a> {
768 rendered_views: &'a HashMap<usize, ElementBox>,
769 pub font_cache: &'a FontCache,
770 pub app: &'a AppContext,
771}
772
773#[derive(Clone, Copy, Debug, Eq, PartialEq)]
774pub enum Axis {
775 Horizontal,
776 Vertical,
777}
778
779impl Axis {
780 pub fn invert(self) -> Self {
781 match self {
782 Self::Horizontal => Self::Vertical,
783 Self::Vertical => Self::Horizontal,
784 }
785 }
786}
787
788impl ToJson for Axis {
789 fn to_json(&self) -> serde_json::Value {
790 match self {
791 Axis::Horizontal => json!("horizontal"),
792 Axis::Vertical => json!("vertical"),
793 }
794 }
795}
796
797pub trait Vector2FExt {
798 fn along(self, axis: Axis) -> f32;
799}
800
801impl Vector2FExt for Vector2F {
802 fn along(self, axis: Axis) -> f32 {
803 match axis {
804 Axis::Horizontal => self.x(),
805 Axis::Vertical => self.y(),
806 }
807 }
808}
809
810#[derive(Copy, Clone, Debug)]
811pub struct SizeConstraint {
812 pub min: Vector2F,
813 pub max: Vector2F,
814}
815
816impl SizeConstraint {
817 pub fn new(min: Vector2F, max: Vector2F) -> Self {
818 Self { min, max }
819 }
820
821 pub fn strict(size: Vector2F) -> Self {
822 Self {
823 min: size,
824 max: size,
825 }
826 }
827
828 pub fn strict_along(axis: Axis, max: f32) -> Self {
829 match axis {
830 Axis::Horizontal => Self {
831 min: vec2f(max, 0.0),
832 max: vec2f(max, f32::INFINITY),
833 },
834 Axis::Vertical => Self {
835 min: vec2f(0.0, max),
836 max: vec2f(f32::INFINITY, max),
837 },
838 }
839 }
840
841 pub fn max_along(&self, axis: Axis) -> f32 {
842 match axis {
843 Axis::Horizontal => self.max.x(),
844 Axis::Vertical => self.max.y(),
845 }
846 }
847
848 pub fn min_along(&self, axis: Axis) -> f32 {
849 match axis {
850 Axis::Horizontal => self.min.x(),
851 Axis::Vertical => self.min.y(),
852 }
853 }
854
855 pub fn constrain(&self, size: Vector2F) -> Vector2F {
856 vec2f(
857 size.x().min(self.max.x()).max(self.min.x()),
858 size.y().min(self.max.y()).max(self.min.y()),
859 )
860 }
861}
862
863impl Default for SizeConstraint {
864 fn default() -> Self {
865 SizeConstraint {
866 min: Vector2F::zero(),
867 max: Vector2F::splat(f32::INFINITY),
868 }
869 }
870}
871
872impl ToJson for SizeConstraint {
873 fn to_json(&self) -> serde_json::Value {
874 json!({
875 "min": self.min.to_json(),
876 "max": self.max.to_json(),
877 })
878 }
879}
880
881pub struct ChildView {
882 view: AnyViewHandle,
883}
884
885impl ChildView {
886 pub fn new(view: impl Into<AnyViewHandle>) -> Self {
887 Self { view: view.into() }
888 }
889}
890
891impl Element for ChildView {
892 type LayoutState = ();
893 type PaintState = ();
894
895 fn layout(
896 &mut self,
897 constraint: SizeConstraint,
898 cx: &mut LayoutContext,
899 ) -> (Vector2F, Self::LayoutState) {
900 let size = cx.layout(self.view.id(), constraint);
901 (size, ())
902 }
903
904 fn paint(
905 &mut self,
906 bounds: RectF,
907 visible_bounds: RectF,
908 _: &mut Self::LayoutState,
909 cx: &mut PaintContext,
910 ) -> Self::PaintState {
911 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
912 }
913
914 fn dispatch_event(
915 &mut self,
916 event: &Event,
917 _: RectF,
918 _: RectF,
919 _: &mut Self::LayoutState,
920 _: &mut Self::PaintState,
921 cx: &mut EventContext,
922 ) -> bool {
923 cx.dispatch_event(self.view.id(), event)
924 }
925
926 fn debug(
927 &self,
928 bounds: RectF,
929 _: &Self::LayoutState,
930 _: &Self::PaintState,
931 cx: &DebugContext,
932 ) -> serde_json::Value {
933 json!({
934 "type": "ChildView",
935 "view_id": self.view.id(),
936 "bounds": bounds.to_json(),
937 "view": self.view.debug_json(cx.app),
938 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
939 view.debug(cx)
940 } else {
941 json!(null)
942 }
943 })
944 }
945}