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::{
10 ClickRegionEvent, CursorRegion, DownOutRegionEvent, DownRegionEvent, DragRegionEvent,
11 HoverRegionEvent, MouseRegionEvent, MoveRegionEvent, UpOutRegionEvent, UpRegionEvent,
12 },
13 text_layout::TextLayoutCache,
14 Action, AnyModelHandle, AnyViewHandle, AnyWeakModelHandle, AssetCache, ElementBox, Entity,
15 FontSystem, ModelHandle, MouseButton, MouseMovedEvent, MouseRegion, MouseRegionId, ParentId,
16 ReadModel, ReadView, RenderContext, RenderParams, Scene, UpgradeModelHandle, UpgradeViewHandle,
17 View, ViewHandle, WeakModelHandle, WeakViewHandle,
18};
19use collections::{HashMap, HashSet};
20use pathfinder_geometry::vector::{vec2f, Vector2F};
21use serde_json::json;
22use smallvec::SmallVec;
23use std::{
24 marker::PhantomData,
25 ops::{Deref, DerefMut, Range},
26 sync::Arc,
27};
28
29pub struct Presenter {
30 window_id: usize,
31 pub(crate) rendered_views: HashMap<usize, ElementBox>,
32 cursor_regions: Vec<CursorRegion>,
33 mouse_regions: Vec<(MouseRegion, usize)>,
34 font_cache: Arc<FontCache>,
35 text_layout_cache: TextLayoutCache,
36 asset_cache: Arc<AssetCache>,
37 last_mouse_moved_event: Option<Event>,
38 hovered_region_ids: HashSet<MouseRegionId>,
39 clicked_regions: Vec<MouseRegion>,
40 clicked_button: Option<MouseButton>,
41 mouse_position: Vector2F,
42 titlebar_height: f32,
43}
44
45impl Presenter {
46 pub fn new(
47 window_id: usize,
48 titlebar_height: f32,
49 font_cache: Arc<FontCache>,
50 text_layout_cache: TextLayoutCache,
51 asset_cache: Arc<AssetCache>,
52 cx: &mut MutableAppContext,
53 ) -> Self {
54 Self {
55 window_id,
56 rendered_views: cx.render_views(window_id, titlebar_height),
57 cursor_regions: Default::default(),
58 mouse_regions: Default::default(),
59 font_cache,
60 text_layout_cache,
61 asset_cache,
62 last_mouse_moved_event: None,
63 hovered_region_ids: Default::default(),
64 clicked_regions: Vec::new(),
65 clicked_button: None,
66 mouse_position: vec2f(0., 0.),
67 titlebar_height,
68 }
69 }
70
71 pub fn invalidate(
72 &mut self,
73 invalidation: &mut WindowInvalidation,
74 cx: &mut MutableAppContext,
75 ) {
76 cx.start_frame();
77 for view_id in &invalidation.removed {
78 invalidation.updated.remove(view_id);
79 self.rendered_views.remove(view_id);
80 }
81 for view_id in &invalidation.updated {
82 self.rendered_views.insert(
83 *view_id,
84 cx.render_view(RenderParams {
85 window_id: self.window_id,
86 view_id: *view_id,
87 titlebar_height: self.titlebar_height,
88 hovered_region_ids: self.hovered_region_ids.clone(),
89 clicked_region_ids: self.clicked_button.map(|button| {
90 (
91 self.clicked_regions
92 .iter()
93 .filter_map(MouseRegion::id)
94 .collect(),
95 button,
96 )
97 }),
98 refreshing: false,
99 })
100 .unwrap(),
101 );
102 }
103 }
104
105 pub fn refresh(&mut self, invalidation: &mut WindowInvalidation, cx: &mut MutableAppContext) {
106 self.invalidate(invalidation, cx);
107 for (view_id, view) in &mut self.rendered_views {
108 if !invalidation.updated.contains(view_id) {
109 *view = cx
110 .render_view(RenderParams {
111 window_id: self.window_id,
112 view_id: *view_id,
113 titlebar_height: self.titlebar_height,
114 hovered_region_ids: self.hovered_region_ids.clone(),
115 clicked_region_ids: self.clicked_button.map(|button| {
116 (
117 self.clicked_regions
118 .iter()
119 .filter_map(MouseRegion::id)
120 .collect(),
121 button,
122 )
123 }),
124 refreshing: true,
125 })
126 .unwrap();
127 }
128 }
129 }
130
131 pub fn build_scene(
132 &mut self,
133 window_size: Vector2F,
134 scale_factor: f32,
135 refreshing: bool,
136 cx: &mut MutableAppContext,
137 ) -> Scene {
138 let mut scene = Scene::new(scale_factor);
139
140 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
141 self.layout(window_size, refreshing, cx);
142 let mut paint_cx = self.build_paint_context(&mut scene, window_size, cx);
143 paint_cx.paint(
144 root_view_id,
145 Vector2F::zero(),
146 RectF::new(Vector2F::zero(), window_size),
147 );
148 self.text_layout_cache.finish_frame();
149 self.cursor_regions = scene.cursor_regions();
150 self.mouse_regions = scene.mouse_regions();
151
152 if cx.window_is_active(self.window_id) {
153 if let Some(event) = self.last_mouse_moved_event.clone() {
154 self.dispatch_event(event, true, cx);
155 }
156 }
157 } else {
158 log::error!("could not find root_view_id for window {}", self.window_id);
159 }
160
161 scene
162 }
163
164 fn layout(&mut self, window_size: Vector2F, refreshing: bool, cx: &mut MutableAppContext) {
165 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
166 self.build_layout_context(window_size, refreshing, cx)
167 .layout(root_view_id, SizeConstraint::strict(window_size));
168 }
169 }
170
171 pub fn build_layout_context<'a>(
172 &'a mut self,
173 window_size: Vector2F,
174 refreshing: bool,
175 cx: &'a mut MutableAppContext,
176 ) -> LayoutContext<'a> {
177 LayoutContext {
178 window_id: self.window_id,
179 rendered_views: &mut self.rendered_views,
180 font_cache: &self.font_cache,
181 font_system: cx.platform().fonts(),
182 text_layout_cache: &self.text_layout_cache,
183 asset_cache: &self.asset_cache,
184 view_stack: Vec::new(),
185 refreshing,
186 hovered_region_ids: self.hovered_region_ids.clone(),
187 clicked_region_ids: self.clicked_button.map(|button| {
188 (
189 self.clicked_regions
190 .iter()
191 .filter_map(MouseRegion::id)
192 .collect(),
193 button,
194 )
195 }),
196 titlebar_height: self.titlebar_height,
197 window_size,
198 app: cx,
199 }
200 }
201
202 pub fn build_paint_context<'a>(
203 &'a mut self,
204 scene: &'a mut Scene,
205 window_size: Vector2F,
206 cx: &'a mut MutableAppContext,
207 ) -> PaintContext {
208 PaintContext {
209 scene,
210 window_size,
211 font_cache: &self.font_cache,
212 text_layout_cache: &self.text_layout_cache,
213 rendered_views: &mut self.rendered_views,
214 view_stack: Vec::new(),
215 app: cx,
216 }
217 }
218
219 pub fn rect_for_text_range(&self, range_utf16: Range<usize>, cx: &AppContext) -> Option<RectF> {
220 cx.focused_view_id(self.window_id).and_then(|view_id| {
221 let cx = MeasurementContext {
222 app: cx,
223 rendered_views: &self.rendered_views,
224 window_id: self.window_id,
225 };
226 cx.rect_for_text_range(view_id, range_utf16)
227 })
228 }
229
230 pub fn dispatch_event(
231 &mut self,
232 event: Event,
233 event_reused: bool,
234 cx: &mut MutableAppContext,
235 ) -> bool {
236 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
237 let mut events_to_send = Vec::new();
238
239 //1. Allocate the correct set of GPUI events generated from the platform events
240 // -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
241 // -> Also moves around mouse related state
242 match &event {
243 Event::MouseDown(e) => {
244 //Click events are weird because they can be fired after a drag event.
245 //MDN says that browsers handle this by starting from 'the most
246 //specific ancestor element that contained both [positions]'
247 //So we need to store the overlapping regions on mouse down.
248 self.clicked_regions = self
249 .mouse_regions
250 .iter()
251 .filter_map(|(region, _)| {
252 region
253 .bounds
254 .contains_point(e.position)
255 .then(|| region.clone())
256 })
257 .collect();
258 self.clicked_button = Some(e.button);
259
260 events_to_send.push(MouseRegionEvent::Down(DownRegionEvent {
261 region: Default::default(),
262 platform_event: e.clone(),
263 }));
264 events_to_send.push(MouseRegionEvent::DownOut(DownOutRegionEvent {
265 region: Default::default(),
266 platform_event: e.clone(),
267 }));
268 }
269 Event::MouseUp(e) => {
270 //NOTE: The order of event pushes is important! MouseUp events MUST be fired
271 //before click events, and so the UpRegionEvent events need to be pushed before
272 //ClickRegionEvents
273 events_to_send.push(MouseRegionEvent::Up(UpRegionEvent {
274 region: Default::default(),
275 platform_event: e.clone(),
276 }));
277 events_to_send.push(MouseRegionEvent::UpOut(UpOutRegionEvent {
278 region: Default::default(),
279 platform_event: e.clone(),
280 }));
281 events_to_send.push(MouseRegionEvent::Click(ClickRegionEvent {
282 region: Default::default(),
283 platform_event: e.clone(),
284 }));
285 }
286 Event::MouseMoved(
287 e @ MouseMovedEvent {
288 position,
289 pressed_button,
290 ..
291 },
292 ) => {
293 let mut style_to_assign = CursorStyle::Arrow;
294 for region in self.cursor_regions.iter().rev() {
295 if region.bounds.contains_point(*position) {
296 style_to_assign = region.style;
297 break;
298 }
299 }
300 cx.platform().set_cursor_style(style_to_assign);
301
302 if pressed_button.is_some() {
303 events_to_send.push(MouseRegionEvent::Drag(DragRegionEvent {
304 region: Default::default(),
305 prev_mouse_position: self.mouse_position,
306 platform_event: e.clone(),
307 }));
308 }
309
310 events_to_send.push(MouseRegionEvent::Move(MoveRegionEvent {
311 region: Default::default(),
312 platform_event: e.clone(),
313 }));
314
315 events_to_send.push(MouseRegionEvent::Hover(HoverRegionEvent {
316 region: Default::default(),
317 platform_event: e.clone(),
318 started: true,
319 }));
320
321 events_to_send.push(MouseRegionEvent::Hover(HoverRegionEvent {
322 region: Default::default(),
323 platform_event: e.clone(),
324 started: false,
325 }));
326
327 self.last_mouse_moved_event = Some(event.clone());
328 }
329 _ => {}
330 }
331
332 if let Some(position) = event.position() {
333 self.mouse_position = position;
334 }
335
336 let mut invalidated_views: HashSet<usize> = Default::default();
337 let mut any_event_handled = false;
338 //2. Process the raw mouse events into region events
339 for mut region_event in events_to_send {
340 let mut valid_regions = Vec::new();
341
342 //GPUI elements are arranged by depth but sibling elements can register overlapping
343 //mouse regions. As such, hover events are only fired on overlapping elements which
344 //are at the same depth as the deepest element which overlaps with the mouse.
345 if let MouseRegionEvent::Hover(_) = region_event {
346 let mut top_most_depth = None;
347 let mouse_position = self.mouse_position.clone();
348 for (region, depth) in self.mouse_regions.iter().rev() {
349 let contains_mouse = region.bounds.contains_point(mouse_position);
350
351 if contains_mouse && top_most_depth.is_none() {
352 top_most_depth = Some(depth);
353 }
354
355 if let Some(region_id) = region.id() {
356 //This unwrap relies on short circuiting boolean expressions
357 //The right side of the && is only executed when contains_mouse
358 //is true, and we know above that when contains_mouse is true
359 //top_most_depth is set
360 if contains_mouse && depth == top_most_depth.unwrap() {
361 //Ensure that hover entrance events aren't sent twice
362 if self.hovered_region_ids.insert(region_id) {
363 valid_regions.push(region.clone());
364 }
365 } else {
366 //Ensure that hover exit events aren't sent twice
367 if self.hovered_region_ids.remove(®ion_id) {
368 valid_regions.push(region.clone());
369 }
370 }
371 }
372 }
373 } else if let MouseRegionEvent::Click(e) = ®ion_event {
374 //Clear presenter state
375 let clicked_regions = std::mem::replace(&mut self.clicked_regions, Vec::new());
376 self.clicked_button = None;
377
378 //Find regions which still overlap with the mouse since the last MouseDown happened
379 for clicked_region in clicked_regions.into_iter().rev() {
380 if clicked_region.bounds.contains_point(e.position) {
381 valid_regions.push(clicked_region);
382 }
383 }
384 } else if region_event.is_local() {
385 for (mouse_region, _) in self.mouse_regions.iter().rev() {
386 //Contains
387 if mouse_region.bounds.contains_point(self.mouse_position) {
388 valid_regions.push(mouse_region.clone());
389 }
390 }
391 } else {
392 for (mouse_region, _) in self.mouse_regions.iter().rev() {
393 //NOT contains
394 if !mouse_region.bounds.contains_point(self.mouse_position) {
395 valid_regions.push(mouse_region.clone());
396 }
397 }
398 }
399
400 //3. Fire region events
401 let hovered_region_ids = self.hovered_region_ids.clone();
402 let mut event_cx = self.build_event_context(cx);
403 for valid_region in valid_regions.into_iter() {
404 region_event.set_region(valid_region.bounds);
405 if let MouseRegionEvent::Hover(e) = &mut region_event {
406 e.started = valid_region
407 .id()
408 .map(|region_id| hovered_region_ids.contains(®ion_id))
409 .unwrap_or(false)
410 }
411
412 if let Some(callback) = valid_region.handlers.get(®ion_event.handler_key()) {
413 if event_reused {
414 invalidated_views.insert(valid_region.view_id);
415 }
416
417 event_cx.handled = true;
418 let local = region_event.is_local();
419 event_cx.with_current_view(valid_region.view_id, {
420 let region_event = region_event.clone();
421 |cx| {
422 callback(region_event, cx);
423 }
424 });
425
426 // For bubbling events, if the event was handled, don't continue dispatching
427 // This only makes sense for local events. 'Out*' events are already
428 if event_cx.handled && local {
429 break;
430 }
431 }
432 }
433
434 invalidated_views.extend(event_cx.invalidated_views);
435 any_event_handled = any_event_handled && event_cx.handled;
436 }
437
438 if !any_event_handled {
439 let mut event_cx = self.build_event_context(cx);
440 any_event_handled = event_cx.dispatch_event(root_view_id, &event);
441 invalidated_views.extend(event_cx.invalidated_views);
442 }
443
444 for view_id in invalidated_views {
445 cx.notify_view(self.window_id, view_id);
446 }
447
448 any_event_handled
449 } else {
450 false
451 }
452 }
453
454 pub fn build_event_context<'a>(
455 &'a mut self,
456 cx: &'a mut MutableAppContext,
457 ) -> EventContext<'a> {
458 EventContext {
459 rendered_views: &mut self.rendered_views,
460 font_cache: &self.font_cache,
461 text_layout_cache: &self.text_layout_cache,
462 view_stack: Default::default(),
463 invalidated_views: Default::default(),
464 notify_count: 0,
465 handled: false,
466 window_id: self.window_id,
467 app: cx,
468 }
469 }
470
471 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
472 let view = cx.root_view(self.window_id)?;
473 Some(json!({
474 "root_view": view.debug_json(cx),
475 "root_element": self.rendered_views.get(&view.id())
476 .map(|root_element| {
477 root_element.debug(&DebugContext {
478 rendered_views: &self.rendered_views,
479 font_cache: &self.font_cache,
480 app: cx,
481 })
482 })
483 }))
484 }
485}
486
487pub struct LayoutContext<'a> {
488 window_id: usize,
489 rendered_views: &'a mut HashMap<usize, ElementBox>,
490 view_stack: Vec<usize>,
491 pub font_cache: &'a Arc<FontCache>,
492 pub font_system: Arc<dyn FontSystem>,
493 pub text_layout_cache: &'a TextLayoutCache,
494 pub asset_cache: &'a AssetCache,
495 pub app: &'a mut MutableAppContext,
496 pub refreshing: bool,
497 pub window_size: Vector2F,
498 titlebar_height: f32,
499 hovered_region_ids: HashSet<MouseRegionId>,
500 clicked_region_ids: Option<(Vec<MouseRegionId>, MouseButton)>,
501}
502
503impl<'a> LayoutContext<'a> {
504 pub(crate) fn keystrokes_for_action(
505 &self,
506 action: &dyn Action,
507 ) -> Option<SmallVec<[Keystroke; 2]>> {
508 self.app
509 .keystrokes_for_action(self.window_id, &self.view_stack, action)
510 }
511
512 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
513 let print_error = |view_id| {
514 format!(
515 "{} with id {}",
516 self.app.name_for_view(self.window_id, view_id).unwrap(),
517 view_id,
518 )
519 };
520 match (
521 self.view_stack.last(),
522 self.app.parents.get(&(self.window_id, view_id)),
523 ) {
524 (Some(layout_parent), Some(ParentId::View(app_parent))) => {
525 if layout_parent != app_parent {
526 panic!(
527 "View {} was laid out with parent {} when it was constructed with parent {}",
528 print_error(view_id),
529 print_error(*layout_parent),
530 print_error(*app_parent))
531 }
532 }
533 (None, Some(ParentId::View(app_parent))) => panic!(
534 "View {} was laid out without a parent when it was constructed with parent {}",
535 print_error(view_id),
536 print_error(*app_parent)
537 ),
538 (Some(layout_parent), Some(ParentId::Root)) => panic!(
539 "View {} was laid out with parent {} when it was constructed as a window root",
540 print_error(view_id),
541 print_error(*layout_parent),
542 ),
543 (_, None) => panic!(
544 "View {} did not have a registered parent in the app context",
545 print_error(view_id),
546 ),
547 _ => {}
548 }
549
550 self.view_stack.push(view_id);
551 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
552 let size = rendered_view.layout(constraint, self);
553 self.rendered_views.insert(view_id, rendered_view);
554 self.view_stack.pop();
555 size
556 }
557
558 pub fn render<F, V, T>(&mut self, handle: &ViewHandle<V>, f: F) -> T
559 where
560 F: FnOnce(&mut V, &mut RenderContext<V>) -> T,
561 V: View,
562 {
563 handle.update(self.app, |view, cx| {
564 let mut render_cx = RenderContext {
565 app: cx,
566 window_id: handle.window_id(),
567 view_id: handle.id(),
568 view_type: PhantomData,
569 titlebar_height: self.titlebar_height,
570 hovered_region_ids: self.hovered_region_ids.clone(),
571 clicked_region_ids: self.clicked_region_ids.clone(),
572 refreshing: self.refreshing,
573 };
574 f(view, &mut render_cx)
575 })
576 }
577}
578
579impl<'a> Deref for LayoutContext<'a> {
580 type Target = MutableAppContext;
581
582 fn deref(&self) -> &Self::Target {
583 self.app
584 }
585}
586
587impl<'a> DerefMut for LayoutContext<'a> {
588 fn deref_mut(&mut self) -> &mut Self::Target {
589 self.app
590 }
591}
592
593impl<'a> ReadView for LayoutContext<'a> {
594 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
595 self.app.read_view(handle)
596 }
597}
598
599impl<'a> ReadModel for LayoutContext<'a> {
600 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
601 self.app.read_model(handle)
602 }
603}
604
605impl<'a> UpgradeModelHandle for LayoutContext<'a> {
606 fn upgrade_model_handle<T: Entity>(
607 &self,
608 handle: &WeakModelHandle<T>,
609 ) -> Option<ModelHandle<T>> {
610 self.app.upgrade_model_handle(handle)
611 }
612
613 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
614 self.app.model_handle_is_upgradable(handle)
615 }
616
617 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
618 self.app.upgrade_any_model_handle(handle)
619 }
620}
621
622impl<'a> UpgradeViewHandle for LayoutContext<'a> {
623 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
624 self.app.upgrade_view_handle(handle)
625 }
626
627 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
628 self.app.upgrade_any_view_handle(handle)
629 }
630}
631
632pub struct PaintContext<'a> {
633 rendered_views: &'a mut HashMap<usize, ElementBox>,
634 view_stack: Vec<usize>,
635 pub window_size: Vector2F,
636 pub scene: &'a mut Scene,
637 pub font_cache: &'a FontCache,
638 pub text_layout_cache: &'a TextLayoutCache,
639 pub app: &'a AppContext,
640}
641
642impl<'a> PaintContext<'a> {
643 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
644 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
645 self.view_stack.push(view_id);
646 tree.paint(origin, visible_bounds, self);
647 self.rendered_views.insert(view_id, tree);
648 self.view_stack.pop();
649 }
650 }
651
652 #[inline]
653 pub fn paint_layer<F>(&mut self, clip_bounds: Option<RectF>, f: F)
654 where
655 F: FnOnce(&mut Self),
656 {
657 self.scene.push_layer(clip_bounds);
658 f(self);
659 self.scene.pop_layer();
660 }
661
662 pub fn current_view_id(&self) -> usize {
663 *self.view_stack.last().unwrap()
664 }
665}
666
667impl<'a> Deref for PaintContext<'a> {
668 type Target = AppContext;
669
670 fn deref(&self) -> &Self::Target {
671 self.app
672 }
673}
674
675pub struct EventContext<'a> {
676 rendered_views: &'a mut HashMap<usize, ElementBox>,
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 handled: bool,
684 invalidated_views: HashSet<usize>,
685}
686
687impl<'a> EventContext<'a> {
688 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
689 if let Some(mut element) = self.rendered_views.remove(&view_id) {
690 let result =
691 self.with_current_view(view_id, |this| element.dispatch_event(event, this));
692 self.rendered_views.insert(view_id, element);
693 result
694 } else {
695 false
696 }
697 }
698
699 fn with_current_view<F, T>(&mut self, view_id: usize, f: F) -> T
700 where
701 F: FnOnce(&mut Self) -> T,
702 {
703 self.view_stack.push(view_id);
704 let result = f(self);
705 self.view_stack.pop();
706 result
707 }
708
709 pub fn window_id(&self) -> usize {
710 self.window_id
711 }
712
713 pub fn view_id(&self) -> Option<usize> {
714 self.view_stack.last().copied()
715 }
716
717 pub fn is_parent_view_focused(&self) -> bool {
718 if let Some(parent_view_id) = self.view_stack.last() {
719 self.app.focused_view_id(self.window_id) == Some(*parent_view_id)
720 } else {
721 false
722 }
723 }
724
725 pub fn focus_parent_view(&mut self) {
726 if let Some(parent_view_id) = self.view_stack.last() {
727 self.app.focus(self.window_id, Some(*parent_view_id))
728 }
729 }
730
731 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
732 self.app
733 .dispatch_any_action_at(self.window_id, *self.view_stack.last().unwrap(), action)
734 }
735
736 pub fn dispatch_action<A: Action>(&mut self, action: A) {
737 self.dispatch_any_action(Box::new(action));
738 }
739
740 pub fn notify(&mut self) {
741 self.notify_count += 1;
742 if let Some(view_id) = self.view_stack.last() {
743 self.invalidated_views.insert(*view_id);
744 }
745 }
746
747 pub fn notify_count(&self) -> usize {
748 self.notify_count
749 }
750
751 pub fn propogate_event(&mut self) {
752 self.handled = false;
753 }
754}
755
756impl<'a> Deref for EventContext<'a> {
757 type Target = MutableAppContext;
758
759 fn deref(&self) -> &Self::Target {
760 self.app
761 }
762}
763
764impl<'a> DerefMut for EventContext<'a> {
765 fn deref_mut(&mut self) -> &mut Self::Target {
766 self.app
767 }
768}
769
770pub struct MeasurementContext<'a> {
771 app: &'a AppContext,
772 rendered_views: &'a HashMap<usize, ElementBox>,
773 pub window_id: usize,
774}
775
776impl<'a> Deref for MeasurementContext<'a> {
777 type Target = AppContext;
778
779 fn deref(&self) -> &Self::Target {
780 self.app
781 }
782}
783
784impl<'a> MeasurementContext<'a> {
785 fn rect_for_text_range(&self, view_id: usize, range_utf16: Range<usize>) -> Option<RectF> {
786 let element = self.rendered_views.get(&view_id)?;
787 element.rect_for_text_range(range_utf16, self)
788 }
789}
790
791pub struct DebugContext<'a> {
792 rendered_views: &'a HashMap<usize, ElementBox>,
793 pub font_cache: &'a FontCache,
794 pub app: &'a AppContext,
795}
796
797#[derive(Clone, Copy, Debug, Eq, PartialEq)]
798pub enum Axis {
799 Horizontal,
800 Vertical,
801}
802
803impl Axis {
804 pub fn invert(self) -> Self {
805 match self {
806 Self::Horizontal => Self::Vertical,
807 Self::Vertical => Self::Horizontal,
808 }
809 }
810}
811
812impl ToJson for Axis {
813 fn to_json(&self) -> serde_json::Value {
814 match self {
815 Axis::Horizontal => json!("horizontal"),
816 Axis::Vertical => json!("vertical"),
817 }
818 }
819}
820
821pub trait Vector2FExt {
822 fn along(self, axis: Axis) -> f32;
823}
824
825impl Vector2FExt for Vector2F {
826 fn along(self, axis: Axis) -> f32 {
827 match axis {
828 Axis::Horizontal => self.x(),
829 Axis::Vertical => self.y(),
830 }
831 }
832}
833
834#[derive(Copy, Clone, Debug)]
835pub struct SizeConstraint {
836 pub min: Vector2F,
837 pub max: Vector2F,
838}
839
840impl SizeConstraint {
841 pub fn new(min: Vector2F, max: Vector2F) -> Self {
842 Self { min, max }
843 }
844
845 pub fn strict(size: Vector2F) -> Self {
846 Self {
847 min: size,
848 max: size,
849 }
850 }
851
852 pub fn strict_along(axis: Axis, max: f32) -> Self {
853 match axis {
854 Axis::Horizontal => Self {
855 min: vec2f(max, 0.0),
856 max: vec2f(max, f32::INFINITY),
857 },
858 Axis::Vertical => Self {
859 min: vec2f(0.0, max),
860 max: vec2f(f32::INFINITY, max),
861 },
862 }
863 }
864
865 pub fn max_along(&self, axis: Axis) -> f32 {
866 match axis {
867 Axis::Horizontal => self.max.x(),
868 Axis::Vertical => self.max.y(),
869 }
870 }
871
872 pub fn min_along(&self, axis: Axis) -> f32 {
873 match axis {
874 Axis::Horizontal => self.min.x(),
875 Axis::Vertical => self.min.y(),
876 }
877 }
878
879 pub fn constrain(&self, size: Vector2F) -> Vector2F {
880 vec2f(
881 size.x().min(self.max.x()).max(self.min.x()),
882 size.y().min(self.max.y()).max(self.min.y()),
883 )
884 }
885}
886
887impl Default for SizeConstraint {
888 fn default() -> Self {
889 SizeConstraint {
890 min: Vector2F::zero(),
891 max: Vector2F::splat(f32::INFINITY),
892 }
893 }
894}
895
896impl ToJson for SizeConstraint {
897 fn to_json(&self) -> serde_json::Value {
898 json!({
899 "min": self.min.to_json(),
900 "max": self.max.to_json(),
901 })
902 }
903}
904
905pub struct ChildView {
906 view: AnyViewHandle,
907}
908
909impl ChildView {
910 pub fn new(view: impl Into<AnyViewHandle>) -> Self {
911 Self { view: view.into() }
912 }
913}
914
915impl Element for ChildView {
916 type LayoutState = ();
917 type PaintState = ();
918
919 fn layout(
920 &mut self,
921 constraint: SizeConstraint,
922 cx: &mut LayoutContext,
923 ) -> (Vector2F, Self::LayoutState) {
924 let size = cx.layout(self.view.id(), constraint);
925 (size, ())
926 }
927
928 fn paint(
929 &mut self,
930 bounds: RectF,
931 visible_bounds: RectF,
932 _: &mut Self::LayoutState,
933 cx: &mut PaintContext,
934 ) -> Self::PaintState {
935 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
936 }
937
938 fn dispatch_event(
939 &mut self,
940 event: &Event,
941 _: RectF,
942 _: RectF,
943 _: &mut Self::LayoutState,
944 _: &mut Self::PaintState,
945 cx: &mut EventContext,
946 ) -> bool {
947 cx.dispatch_event(self.view.id(), event)
948 }
949
950 fn rect_for_text_range(
951 &self,
952 range_utf16: Range<usize>,
953 _: RectF,
954 _: RectF,
955 _: &Self::LayoutState,
956 _: &Self::PaintState,
957 cx: &MeasurementContext,
958 ) -> Option<RectF> {
959 cx.rect_for_text_range(self.view.id(), range_utf16)
960 }
961
962 fn debug(
963 &self,
964 bounds: RectF,
965 _: &Self::LayoutState,
966 _: &Self::PaintState,
967 cx: &DebugContext,
968 ) -> serde_json::Value {
969 json!({
970 "type": "ChildView",
971 "view_id": self.view.id(),
972 "bounds": bounds.to_json(),
973 "view": self.view.debug_json(cx.app),
974 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
975 view.debug(cx)
976 } else {
977 json!(null)
978 }
979 })
980 }
981}