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, MouseButton, MouseEvent, MouseMovedEvent, MouseRegion, MouseRegionId,
13 ReadModel, ReadView, RenderContext, RenderParams, Scene, UpgradeModelHandle, UpgradeViewHandle,
14 View, ViewHandle, WeakModelHandle, 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, Range},
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 rect_for_text_range(&self, range_utf16: Range<usize>, cx: &AppContext) -> Option<RectF> {
228 cx.focused_view_id(self.window_id).and_then(|view_id| {
229 let cx = MeasurementContext {
230 app: cx,
231 rendered_views: &self.rendered_views,
232 window_id: self.window_id,
233 };
234 cx.rect_for_text_range(view_id, range_utf16)
235 })
236 }
237
238 pub fn dispatch_event(&mut self, event: Event, cx: &mut MutableAppContext) -> bool {
239 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
240 let mut invalidated_views = Vec::new();
241 let mut mouse_down_out_handlers = Vec::new();
242 let mut mouse_down_region = None;
243 let mut clicked_region = None;
244 let mut right_mouse_down_region = None;
245 let mut right_clicked_region = None;
246 let mut dragged_region = None;
247
248 match event {
249 Event::MouseDown(MouseEvent {
250 position,
251 button: MouseButton::Left,
252 ..
253 }) => {
254 let mut hit = false;
255 for (region, _) in self.mouse_regions.iter().rev() {
256 if region.bounds.contains_point(position) {
257 if !hit {
258 hit = true;
259 invalidated_views.push(region.view_id);
260 mouse_down_region = Some((region.clone(), position));
261 self.clicked_region = Some(region.clone());
262 self.prev_drag_position = Some(position);
263 }
264 } else if let Some(handler) = region.mouse_down_out.clone() {
265 mouse_down_out_handlers.push((handler, region.view_id, position));
266 }
267 }
268 }
269 Event::MouseUp(MouseEvent {
270 position,
271 click_count,
272 button: MouseButton::Left,
273 ..
274 }) => {
275 self.prev_drag_position.take();
276 if let Some(region) = self.clicked_region.take() {
277 invalidated_views.push(region.view_id);
278 if region.bounds.contains_point(position) {
279 clicked_region = Some((region, position, click_count));
280 }
281 }
282 }
283 Event::MouseDown(MouseEvent {
284 position,
285 button: MouseButton::Right,
286 ..
287 }) => {
288 let mut hit = false;
289 for (region, _) in self.mouse_regions.iter().rev() {
290 if region.bounds.contains_point(position) {
291 if !hit {
292 hit = true;
293 invalidated_views.push(region.view_id);
294 right_mouse_down_region = Some((region.clone(), position));
295 self.right_clicked_region = Some(region.clone());
296 }
297 } else if let Some(handler) = region.right_mouse_down_out.clone() {
298 mouse_down_out_handlers.push((handler, region.view_id, position));
299 }
300 }
301 }
302 Event::MouseUp(MouseEvent {
303 position,
304 click_count,
305 button: MouseButton::Right,
306 ..
307 }) => {
308 if let Some(region) = self.right_clicked_region.take() {
309 invalidated_views.push(region.view_id);
310 if region.bounds.contains_point(position) {
311 right_clicked_region = Some((region, position, click_count));
312 }
313 }
314 }
315 Event::MouseMoved(MouseMovedEvent {
316 pressed_button,
317 position,
318 shift,
319 ctrl,
320 alt,
321 cmd,
322 ..
323 }) => {
324 if let Some(MouseButton::Left) = pressed_button {
325 if let Some((clicked_region, prev_drag_position)) = self
326 .clicked_region
327 .as_ref()
328 .zip(self.prev_drag_position.as_mut())
329 {
330 dragged_region =
331 Some((clicked_region.clone(), *prev_drag_position, position));
332 *prev_drag_position = position;
333 }
334
335 self.last_mouse_moved_event = Some(Event::MouseMoved(MouseMovedEvent {
336 position,
337 pressed_button: Some(MouseButton::Left),
338 shift,
339 ctrl,
340 alt,
341 cmd,
342 }));
343 }
344
345 self.last_mouse_moved_event = Some(event.clone());
346 }
347 _ => {}
348 }
349
350 let (mut handled, mut event_cx) =
351 self.handle_hover_events(&event, &mut invalidated_views, cx);
352
353 for (handler, view_id, position) in mouse_down_out_handlers {
354 event_cx.with_current_view(view_id, |event_cx| handler(position, event_cx))
355 }
356
357 if let Some((mouse_down_region, position)) = mouse_down_region {
358 handled = true;
359 if let Some(mouse_down_callback) = mouse_down_region.mouse_down {
360 event_cx.with_current_view(mouse_down_region.view_id, |event_cx| {
361 mouse_down_callback(position, event_cx);
362 })
363 }
364 }
365
366 if let Some((clicked_region, position, click_count)) = clicked_region {
367 handled = true;
368 if let Some(click_callback) = clicked_region.click {
369 event_cx.with_current_view(clicked_region.view_id, |event_cx| {
370 click_callback(position, click_count, event_cx);
371 })
372 }
373 }
374
375 if let Some((right_mouse_down_region, position)) = right_mouse_down_region {
376 handled = true;
377 if let Some(right_mouse_down_callback) = right_mouse_down_region.right_mouse_down {
378 event_cx.with_current_view(right_mouse_down_region.view_id, |event_cx| {
379 right_mouse_down_callback(position, event_cx);
380 })
381 }
382 }
383
384 if let Some((right_clicked_region, position, click_count)) = right_clicked_region {
385 handled = true;
386 if let Some(right_click_callback) = right_clicked_region.right_click {
387 event_cx.with_current_view(right_clicked_region.view_id, |event_cx| {
388 right_click_callback(position, click_count, event_cx);
389 })
390 }
391 }
392
393 if let Some((dragged_region, prev_position, position)) = dragged_region {
394 handled = true;
395 if let Some(drag_callback) = dragged_region.drag {
396 event_cx.with_current_view(dragged_region.view_id, |event_cx| {
397 drag_callback(prev_position, position, event_cx);
398 })
399 }
400 }
401
402 if !handled {
403 handled = event_cx.dispatch_event(root_view_id, &event);
404 }
405
406 invalidated_views.extend(event_cx.invalidated_views);
407 let dispatch_directives = event_cx.dispatched_actions;
408
409 for view_id in invalidated_views {
410 cx.notify_view(self.window_id, view_id);
411 }
412
413 let mut dispatch_path = Vec::new();
414 for directive in dispatch_directives {
415 dispatch_path.clear();
416 if let Some(view_id) = directive.dispatcher_view_id {
417 self.compute_dispatch_path_from(view_id, &mut dispatch_path);
418 }
419 cx.dispatch_action_any(self.window_id, &dispatch_path, directive.action.as_ref());
420 }
421
422 handled
423 } else {
424 false
425 }
426 }
427
428 fn handle_hover_events<'a>(
429 &'a mut self,
430 event: &Event,
431 invalidated_views: &mut Vec<usize>,
432 cx: &'a mut MutableAppContext,
433 ) -> (bool, EventContext<'a>) {
434 let mut unhovered_regions = Vec::new();
435 let mut hovered_regions = Vec::new();
436
437 if let Event::MouseMoved(MouseMovedEvent {
438 position,
439 pressed_button,
440 ..
441 }) = event
442 {
443 if let None = pressed_button {
444 let mut style_to_assign = CursorStyle::Arrow;
445 for region in self.cursor_regions.iter().rev() {
446 if region.bounds.contains_point(*position) {
447 style_to_assign = region.style;
448 break;
449 }
450 }
451 cx.platform().set_cursor_style(style_to_assign);
452
453 let mut hover_depth = None;
454 for (region, depth) in self.mouse_regions.iter().rev() {
455 if region.bounds.contains_point(*position)
456 && hover_depth.map_or(true, |hover_depth| hover_depth == *depth)
457 {
458 hover_depth = Some(*depth);
459 if let Some(region_id) = region.id() {
460 if !self.hovered_region_ids.contains(®ion_id) {
461 invalidated_views.push(region.view_id);
462 hovered_regions.push((region.clone(), position));
463 self.hovered_region_ids.insert(region_id);
464 }
465 }
466 } else {
467 if let Some(region_id) = region.id() {
468 if self.hovered_region_ids.contains(®ion_id) {
469 invalidated_views.push(region.view_id);
470 unhovered_regions.push((region.clone(), position));
471 self.hovered_region_ids.remove(®ion_id);
472 }
473 }
474 }
475 }
476 }
477 }
478
479 let mut event_cx = self.build_event_context(cx);
480 let mut handled = false;
481
482 for (unhovered_region, position) in unhovered_regions {
483 handled = true;
484 if let Some(hover_callback) = unhovered_region.hover {
485 event_cx.with_current_view(unhovered_region.view_id, |event_cx| {
486 hover_callback(*position, false, event_cx);
487 })
488 }
489 }
490
491 for (hovered_region, position) in hovered_regions {
492 handled = true;
493 if let Some(hover_callback) = hovered_region.hover {
494 event_cx.with_current_view(hovered_region.view_id, |event_cx| {
495 hover_callback(*position, true, event_cx);
496 })
497 }
498 }
499
500 (handled, event_cx)
501 }
502
503 pub fn build_event_context<'a>(
504 &'a mut self,
505 cx: &'a mut MutableAppContext,
506 ) -> EventContext<'a> {
507 EventContext {
508 rendered_views: &mut self.rendered_views,
509 dispatched_actions: Default::default(),
510 font_cache: &self.font_cache,
511 text_layout_cache: &self.text_layout_cache,
512 view_stack: Default::default(),
513 invalidated_views: Default::default(),
514 notify_count: 0,
515 window_id: self.window_id,
516 app: cx,
517 }
518 }
519
520 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
521 let view = cx.root_view(self.window_id)?;
522 Some(json!({
523 "root_view": view.debug_json(cx),
524 "root_element": self.rendered_views.get(&view.id())
525 .map(|root_element| {
526 root_element.debug(&DebugContext {
527 rendered_views: &self.rendered_views,
528 font_cache: &self.font_cache,
529 app: cx,
530 })
531 })
532 }))
533 }
534}
535
536pub struct DispatchDirective {
537 pub dispatcher_view_id: Option<usize>,
538 pub action: Box<dyn Action>,
539}
540
541pub struct LayoutContext<'a> {
542 window_id: usize,
543 rendered_views: &'a mut HashMap<usize, ElementBox>,
544 parents: &'a mut HashMap<usize, usize>,
545 view_stack: Vec<usize>,
546 pub font_cache: &'a Arc<FontCache>,
547 pub font_system: Arc<dyn FontSystem>,
548 pub text_layout_cache: &'a TextLayoutCache,
549 pub asset_cache: &'a AssetCache,
550 pub app: &'a mut MutableAppContext,
551 pub refreshing: bool,
552 pub window_size: Vector2F,
553 titlebar_height: f32,
554 hovered_region_ids: HashSet<MouseRegionId>,
555 clicked_region_id: Option<MouseRegionId>,
556 right_clicked_region_id: Option<MouseRegionId>,
557}
558
559impl<'a> LayoutContext<'a> {
560 pub(crate) fn keystrokes_for_action(
561 &self,
562 action: &dyn Action,
563 ) -> Option<SmallVec<[Keystroke; 2]>> {
564 self.app
565 .keystrokes_for_action(self.window_id, &self.view_stack, action)
566 }
567
568 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
569 if let Some(parent_id) = self.view_stack.last() {
570 self.parents.insert(view_id, *parent_id);
571 }
572 self.view_stack.push(view_id);
573 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
574 let size = rendered_view.layout(constraint, self);
575 self.rendered_views.insert(view_id, rendered_view);
576 self.view_stack.pop();
577 size
578 }
579
580 pub fn render<F, V, T>(&mut self, handle: &ViewHandle<V>, f: F) -> T
581 where
582 F: FnOnce(&mut V, &mut RenderContext<V>) -> T,
583 V: View,
584 {
585 handle.update(self.app, |view, cx| {
586 let mut render_cx = RenderContext {
587 app: cx,
588 window_id: handle.window_id(),
589 view_id: handle.id(),
590 view_type: PhantomData,
591 titlebar_height: self.titlebar_height,
592 hovered_region_ids: self.hovered_region_ids.clone(),
593 clicked_region_id: self.clicked_region_id,
594 right_clicked_region_id: self.right_clicked_region_id,
595 refreshing: self.refreshing,
596 };
597 f(view, &mut render_cx)
598 })
599 }
600}
601
602impl<'a> Deref for LayoutContext<'a> {
603 type Target = MutableAppContext;
604
605 fn deref(&self) -> &Self::Target {
606 self.app
607 }
608}
609
610impl<'a> DerefMut for LayoutContext<'a> {
611 fn deref_mut(&mut self) -> &mut Self::Target {
612 self.app
613 }
614}
615
616impl<'a> ReadView for LayoutContext<'a> {
617 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
618 self.app.read_view(handle)
619 }
620}
621
622impl<'a> ReadModel for LayoutContext<'a> {
623 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
624 self.app.read_model(handle)
625 }
626}
627
628impl<'a> UpgradeModelHandle for LayoutContext<'a> {
629 fn upgrade_model_handle<T: Entity>(
630 &self,
631 handle: &WeakModelHandle<T>,
632 ) -> Option<ModelHandle<T>> {
633 self.app.upgrade_model_handle(handle)
634 }
635
636 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
637 self.app.model_handle_is_upgradable(handle)
638 }
639
640 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
641 self.app.upgrade_any_model_handle(handle)
642 }
643}
644
645impl<'a> UpgradeViewHandle for LayoutContext<'a> {
646 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
647 self.app.upgrade_view_handle(handle)
648 }
649
650 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
651 self.app.upgrade_any_view_handle(handle)
652 }
653}
654
655pub struct PaintContext<'a> {
656 rendered_views: &'a mut HashMap<usize, ElementBox>,
657 view_stack: Vec<usize>,
658 pub window_size: Vector2F,
659 pub scene: &'a mut Scene,
660 pub font_cache: &'a FontCache,
661 pub text_layout_cache: &'a TextLayoutCache,
662 pub app: &'a AppContext,
663}
664
665impl<'a> PaintContext<'a> {
666 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
667 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
668 self.view_stack.push(view_id);
669 tree.paint(origin, visible_bounds, self);
670 self.rendered_views.insert(view_id, tree);
671 self.view_stack.pop();
672 }
673 }
674
675 #[inline]
676 pub fn paint_layer<F>(&mut self, clip_bounds: Option<RectF>, f: F)
677 where
678 F: FnOnce(&mut Self) -> (),
679 {
680 self.scene.push_layer(clip_bounds);
681 f(self);
682 self.scene.pop_layer();
683 }
684
685 pub fn current_view_id(&self) -> usize {
686 *self.view_stack.last().unwrap()
687 }
688}
689
690impl<'a> Deref for PaintContext<'a> {
691 type Target = AppContext;
692
693 fn deref(&self) -> &Self::Target {
694 self.app
695 }
696}
697
698pub struct EventContext<'a> {
699 rendered_views: &'a mut HashMap<usize, ElementBox>,
700 dispatched_actions: Vec<DispatchDirective>,
701 pub font_cache: &'a FontCache,
702 pub text_layout_cache: &'a TextLayoutCache,
703 pub app: &'a mut MutableAppContext,
704 pub window_id: usize,
705 pub notify_count: usize,
706 view_stack: Vec<usize>,
707 invalidated_views: HashSet<usize>,
708}
709
710impl<'a> EventContext<'a> {
711 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
712 if let Some(mut element) = self.rendered_views.remove(&view_id) {
713 let result =
714 self.with_current_view(view_id, |this| element.dispatch_event(event, this));
715 self.rendered_views.insert(view_id, element);
716 result
717 } else {
718 false
719 }
720 }
721
722 fn with_current_view<F, T>(&mut self, view_id: usize, f: F) -> T
723 where
724 F: FnOnce(&mut Self) -> T,
725 {
726 self.view_stack.push(view_id);
727 let result = f(self);
728 self.view_stack.pop();
729 result
730 }
731
732 pub fn window_id(&self) -> usize {
733 self.window_id
734 }
735
736 pub fn view_id(&self) -> Option<usize> {
737 self.view_stack.last().copied()
738 }
739
740 pub fn is_parent_view_focused(&self) -> bool {
741 if let Some(parent_view_id) = self.view_stack.last() {
742 self.app.focused_view_id(self.window_id) == Some(*parent_view_id)
743 } else {
744 false
745 }
746 }
747
748 pub fn focus_parent_view(&mut self) {
749 if let Some(parent_view_id) = self.view_stack.last() {
750 self.app.focus(self.window_id, Some(*parent_view_id))
751 }
752 }
753
754 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
755 self.dispatched_actions.push(DispatchDirective {
756 dispatcher_view_id: self.view_stack.last().copied(),
757 action,
758 });
759 }
760
761 pub fn dispatch_action<A: Action>(&mut self, action: A) {
762 self.dispatch_any_action(Box::new(action));
763 }
764
765 pub fn notify(&mut self) {
766 self.notify_count += 1;
767 if let Some(view_id) = self.view_stack.last() {
768 self.invalidated_views.insert(*view_id);
769 }
770 }
771
772 pub fn notify_count(&self) -> usize {
773 self.notify_count
774 }
775}
776
777impl<'a> Deref for EventContext<'a> {
778 type Target = MutableAppContext;
779
780 fn deref(&self) -> &Self::Target {
781 self.app
782 }
783}
784
785impl<'a> DerefMut for EventContext<'a> {
786 fn deref_mut(&mut self) -> &mut Self::Target {
787 self.app
788 }
789}
790
791pub struct MeasurementContext<'a> {
792 app: &'a AppContext,
793 rendered_views: &'a HashMap<usize, ElementBox>,
794 pub window_id: usize,
795}
796
797impl<'a> Deref for MeasurementContext<'a> {
798 type Target = AppContext;
799
800 fn deref(&self) -> &Self::Target {
801 self.app
802 }
803}
804
805impl<'a> MeasurementContext<'a> {
806 fn rect_for_text_range(&self, view_id: usize, range_utf16: Range<usize>) -> Option<RectF> {
807 let element = self.rendered_views.get(&view_id)?;
808 element.rect_for_text_range(range_utf16, self)
809 }
810}
811
812pub struct DebugContext<'a> {
813 rendered_views: &'a HashMap<usize, ElementBox>,
814 pub font_cache: &'a FontCache,
815 pub app: &'a AppContext,
816}
817
818#[derive(Clone, Copy, Debug, Eq, PartialEq)]
819pub enum Axis {
820 Horizontal,
821 Vertical,
822}
823
824impl Axis {
825 pub fn invert(self) -> Self {
826 match self {
827 Self::Horizontal => Self::Vertical,
828 Self::Vertical => Self::Horizontal,
829 }
830 }
831}
832
833impl ToJson for Axis {
834 fn to_json(&self) -> serde_json::Value {
835 match self {
836 Axis::Horizontal => json!("horizontal"),
837 Axis::Vertical => json!("vertical"),
838 }
839 }
840}
841
842pub trait Vector2FExt {
843 fn along(self, axis: Axis) -> f32;
844}
845
846impl Vector2FExt for Vector2F {
847 fn along(self, axis: Axis) -> f32 {
848 match axis {
849 Axis::Horizontal => self.x(),
850 Axis::Vertical => self.y(),
851 }
852 }
853}
854
855#[derive(Copy, Clone, Debug)]
856pub struct SizeConstraint {
857 pub min: Vector2F,
858 pub max: Vector2F,
859}
860
861impl SizeConstraint {
862 pub fn new(min: Vector2F, max: Vector2F) -> Self {
863 Self { min, max }
864 }
865
866 pub fn strict(size: Vector2F) -> Self {
867 Self {
868 min: size,
869 max: size,
870 }
871 }
872
873 pub fn strict_along(axis: Axis, max: f32) -> Self {
874 match axis {
875 Axis::Horizontal => Self {
876 min: vec2f(max, 0.0),
877 max: vec2f(max, f32::INFINITY),
878 },
879 Axis::Vertical => Self {
880 min: vec2f(0.0, max),
881 max: vec2f(f32::INFINITY, max),
882 },
883 }
884 }
885
886 pub fn max_along(&self, axis: Axis) -> f32 {
887 match axis {
888 Axis::Horizontal => self.max.x(),
889 Axis::Vertical => self.max.y(),
890 }
891 }
892
893 pub fn min_along(&self, axis: Axis) -> f32 {
894 match axis {
895 Axis::Horizontal => self.min.x(),
896 Axis::Vertical => self.min.y(),
897 }
898 }
899
900 pub fn constrain(&self, size: Vector2F) -> Vector2F {
901 vec2f(
902 size.x().min(self.max.x()).max(self.min.x()),
903 size.y().min(self.max.y()).max(self.min.y()),
904 )
905 }
906}
907
908impl Default for SizeConstraint {
909 fn default() -> Self {
910 SizeConstraint {
911 min: Vector2F::zero(),
912 max: Vector2F::splat(f32::INFINITY),
913 }
914 }
915}
916
917impl ToJson for SizeConstraint {
918 fn to_json(&self) -> serde_json::Value {
919 json!({
920 "min": self.min.to_json(),
921 "max": self.max.to_json(),
922 })
923 }
924}
925
926pub struct ChildView {
927 view: AnyViewHandle,
928}
929
930impl ChildView {
931 pub fn new(view: impl Into<AnyViewHandle>) -> Self {
932 Self { view: view.into() }
933 }
934}
935
936impl Element for ChildView {
937 type LayoutState = ();
938 type PaintState = ();
939
940 fn layout(
941 &mut self,
942 constraint: SizeConstraint,
943 cx: &mut LayoutContext,
944 ) -> (Vector2F, Self::LayoutState) {
945 let size = cx.layout(self.view.id(), constraint);
946 (size, ())
947 }
948
949 fn paint(
950 &mut self,
951 bounds: RectF,
952 visible_bounds: RectF,
953 _: &mut Self::LayoutState,
954 cx: &mut PaintContext,
955 ) -> Self::PaintState {
956 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
957 }
958
959 fn dispatch_event(
960 &mut self,
961 event: &Event,
962 _: RectF,
963 _: RectF,
964 _: &mut Self::LayoutState,
965 _: &mut Self::PaintState,
966 cx: &mut EventContext,
967 ) -> bool {
968 cx.dispatch_event(self.view.id(), event)
969 }
970
971 fn rect_for_text_range(
972 &self,
973 range_utf16: Range<usize>,
974 _: RectF,
975 _: RectF,
976 _: &Self::LayoutState,
977 _: &Self::PaintState,
978 cx: &MeasurementContext,
979 ) -> Option<RectF> {
980 cx.rect_for_text_range(self.view.id(), range_utf16)
981 }
982
983 fn debug(
984 &self,
985 bounds: RectF,
986 _: &Self::LayoutState,
987 _: &Self::PaintState,
988 cx: &DebugContext,
989 ) -> serde_json::Value {
990 json!({
991 "type": "ChildView",
992 "view_id": self.view.id(),
993 "bounds": bounds.to_json(),
994 "view": self.view.debug_json(cx.app),
995 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
996 view.debug(cx)
997 } else {
998 json!(null)
999 }
1000 })
1001 }
1002}