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
249 // If there is already clicked_button stored, don't replace it.
250 if self.clicked_button.is_none() {
251 self.clicked_regions = self
252 .mouse_regions
253 .iter()
254 .filter_map(|(region, _)| {
255 region
256 .bounds
257 .contains_point(e.position)
258 .then(|| region.clone())
259 })
260 .collect();
261 self.clicked_button = Some(e.button);
262 }
263
264 events_to_send.push(MouseRegionEvent::Down(DownRegionEvent {
265 region: Default::default(),
266 platform_event: e.clone(),
267 }));
268 events_to_send.push(MouseRegionEvent::DownOut(DownOutRegionEvent {
269 region: Default::default(),
270 platform_event: e.clone(),
271 }));
272 }
273 Event::MouseUp(e) => {
274 // NOTE: The order of event pushes is important! MouseUp events MUST be fired
275 // before click events, and so the UpRegionEvent events need to be pushed before
276 // ClickRegionEvents
277 events_to_send.push(MouseRegionEvent::Up(UpRegionEvent {
278 region: Default::default(),
279 platform_event: e.clone(),
280 }));
281 events_to_send.push(MouseRegionEvent::UpOut(UpOutRegionEvent {
282 region: Default::default(),
283 platform_event: e.clone(),
284 }));
285 events_to_send.push(MouseRegionEvent::Click(ClickRegionEvent {
286 region: Default::default(),
287 platform_event: e.clone(),
288 }));
289 }
290 Event::MouseMoved(
291 e @ MouseMovedEvent {
292 position,
293 pressed_button,
294 ..
295 },
296 ) => {
297 let mut style_to_assign = CursorStyle::Arrow;
298 for region in self.cursor_regions.iter().rev() {
299 if region.bounds.contains_point(*position) {
300 style_to_assign = region.style;
301 break;
302 }
303 }
304 cx.platform().set_cursor_style(style_to_assign);
305
306 if !event_reused {
307 if pressed_button.is_some() {
308 events_to_send.push(MouseRegionEvent::Drag(DragRegionEvent {
309 region: Default::default(),
310 prev_mouse_position: self.mouse_position,
311 platform_event: e.clone(),
312 }));
313 } else if let Some(clicked_button) = self.clicked_button {
314 // Mouse up event happened outside the current window. Simulate mouse up button event
315 let button_event = e.to_button_event(clicked_button);
316 events_to_send.push(MouseRegionEvent::Up(UpRegionEvent {
317 region: Default::default(),
318 platform_event: button_event.clone(),
319 }));
320 events_to_send.push(MouseRegionEvent::UpOut(UpOutRegionEvent {
321 region: Default::default(),
322 platform_event: button_event.clone(),
323 }));
324 events_to_send.push(MouseRegionEvent::Click(ClickRegionEvent {
325 region: Default::default(),
326 platform_event: button_event.clone(),
327 }));
328 }
329
330 events_to_send.push(MouseRegionEvent::Move(MoveRegionEvent {
331 region: Default::default(),
332 platform_event: e.clone(),
333 }));
334 }
335
336 events_to_send.push(MouseRegionEvent::Hover(HoverRegionEvent {
337 region: Default::default(),
338 platform_event: e.clone(),
339 started: false,
340 }));
341
342 self.last_mouse_moved_event = Some(event.clone());
343 }
344
345 _ => {}
346 }
347
348 if let Some(position) = event.position() {
349 self.mouse_position = position;
350 }
351
352 let mut invalidated_views: HashSet<usize> = Default::default();
353 let mut any_event_handled = false;
354 // 2. Process the raw mouse events into region events
355 for mut region_event in events_to_send {
356 let mut valid_regions = Vec::new();
357
358 // GPUI elements are arranged by depth but sibling elements can register overlapping
359 // mouse regions. As such, hover events are only fired on overlapping elements which
360 // are at the same depth as the topmost element which overlaps with the mouse.
361
362 match ®ion_event {
363 MouseRegionEvent::Hover(_) => {
364 let mut top_most_depth = None;
365 let mouse_position = self.mouse_position.clone();
366 for (region, depth) in self.mouse_regions.iter().rev() {
367 // Allow mouse regions to appear transparent to hovers
368 if !region.hoverable {
369 continue;
370 }
371
372 let contains_mouse = region.bounds.contains_point(mouse_position);
373
374 if contains_mouse && top_most_depth.is_none() {
375 top_most_depth = Some(depth);
376 }
377
378 if let Some(region_id) = region.id() {
379 // This unwrap relies on short circuiting boolean expressions
380 // The right side of the && is only executed when contains_mouse
381 // is true, and we know above that when contains_mouse is true
382 // top_most_depth is set
383 if contains_mouse && depth == top_most_depth.unwrap() {
384 //Ensure that hover entrance events aren't sent twice
385 if self.hovered_region_ids.insert(region_id) {
386 valid_regions.push(region.clone());
387 invalidated_views.insert(region.view_id);
388 }
389 } else {
390 // Ensure that hover exit events aren't sent twice
391 if self.hovered_region_ids.remove(®ion_id) {
392 valid_regions.push(region.clone());
393 invalidated_views.insert(region.view_id);
394 }
395 }
396 }
397 }
398 }
399 MouseRegionEvent::Click(e) => {
400 // Only raise click events if the released button is the same as the one stored
401 if self
402 .clicked_button
403 .map(|clicked_button| clicked_button == e.button)
404 .unwrap_or(false)
405 {
406 // Clear clicked regions and clicked button
407 let clicked_regions =
408 std::mem::replace(&mut self.clicked_regions, Vec::new());
409 self.clicked_button = None;
410
411 // Find regions which still overlap with the mouse since the last MouseDown happened
412 for clicked_region in clicked_regions.into_iter().rev() {
413 if clicked_region.bounds.contains_point(e.position) {
414 valid_regions.push(clicked_region);
415 }
416 }
417 }
418 }
419 MouseRegionEvent::Drag(_) => {
420 for clicked_region in self.clicked_regions.iter().rev() {
421 valid_regions.push(clicked_region.clone());
422 }
423 }
424
425 MouseRegionEvent::UpOut(_) | MouseRegionEvent::DownOut(_) => {
426 for (mouse_region, _) in self.mouse_regions.iter().rev() {
427 // NOT contains
428 if !mouse_region.bounds.contains_point(self.mouse_position) {
429 valid_regions.push(mouse_region.clone());
430 }
431 }
432 }
433 _ => {
434 for (mouse_region, _) in self.mouse_regions.iter().rev() {
435 // Contains
436 if mouse_region.bounds.contains_point(self.mouse_position) {
437 valid_regions.push(mouse_region.clone());
438 }
439 }
440 }
441 }
442
443 //3. Fire region events
444 let hovered_region_ids = self.hovered_region_ids.clone();
445 for valid_region in valid_regions.into_iter() {
446 let mut event_cx = self.build_event_context(&mut invalidated_views, cx);
447
448 region_event.set_region(valid_region.bounds);
449 if let MouseRegionEvent::Hover(e) = &mut region_event {
450 e.started = valid_region
451 .id()
452 .map(|region_id| hovered_region_ids.contains(®ion_id))
453 .unwrap_or(false)
454 }
455 // Handle Down events if the MouseRegion has a Click handler. This makes the api more intuitive as you would
456 // not expect a MouseRegion to be transparent to Down events if it also has a Click handler.
457 // This behavior can be overridden by adding a Down handler that calls cx.propogate_event
458 if let MouseRegionEvent::Down(e) = ®ion_event {
459 if valid_region
460 .handlers
461 .contains_handler(MouseRegionEvent::click_disc(), Some(e.button))
462 {
463 event_cx.handled = true;
464 }
465 }
466
467 if let Some(callback) = valid_region.handlers.get(®ion_event.handler_key()) {
468 event_cx.handled = true;
469 event_cx.invalidated_views.insert(valid_region.view_id);
470 event_cx.with_current_view(valid_region.view_id, {
471 let region_event = region_event.clone();
472 |cx| {
473 callback(region_event, cx);
474 }
475 });
476 }
477
478 any_event_handled = any_event_handled || event_cx.handled;
479 // For bubbling events, if the event was handled, don't continue dispatching
480 // This only makes sense for local events.
481 if event_cx.handled && region_event.is_capturable() {
482 break;
483 }
484 }
485 }
486
487 if !any_event_handled && !event_reused {
488 let mut event_cx = self.build_event_context(&mut invalidated_views, cx);
489 any_event_handled = event_cx.dispatch_event(root_view_id, &event);
490 }
491
492 for view_id in invalidated_views {
493 cx.notify_view(self.window_id, view_id);
494 }
495
496 any_event_handled
497 } else {
498 false
499 }
500 }
501
502 pub fn build_event_context<'a>(
503 &'a mut self,
504 invalidated_views: &'a mut HashSet<usize>,
505 cx: &'a mut MutableAppContext,
506 ) -> EventContext<'a> {
507 EventContext {
508 rendered_views: &mut self.rendered_views,
509 font_cache: &self.font_cache,
510 text_layout_cache: &self.text_layout_cache,
511 view_stack: Default::default(),
512 invalidated_views,
513 notify_count: 0,
514 handled: false,
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 LayoutContext<'a> {
537 window_id: usize,
538 rendered_views: &'a mut HashMap<usize, ElementBox>,
539 view_stack: Vec<usize>,
540 pub font_cache: &'a Arc<FontCache>,
541 pub font_system: Arc<dyn FontSystem>,
542 pub text_layout_cache: &'a TextLayoutCache,
543 pub asset_cache: &'a AssetCache,
544 pub app: &'a mut MutableAppContext,
545 pub refreshing: bool,
546 pub window_size: Vector2F,
547 titlebar_height: f32,
548 hovered_region_ids: HashSet<MouseRegionId>,
549 clicked_region_ids: Option<(Vec<MouseRegionId>, MouseButton)>,
550}
551
552impl<'a> LayoutContext<'a> {
553 pub(crate) fn keystrokes_for_action(
554 &self,
555 action: &dyn Action,
556 ) -> Option<SmallVec<[Keystroke; 2]>> {
557 self.app
558 .keystrokes_for_action(self.window_id, &self.view_stack, action)
559 }
560
561 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
562 let print_error = |view_id| {
563 format!(
564 "{} with id {}",
565 self.app.name_for_view(self.window_id, view_id).unwrap(),
566 view_id,
567 )
568 };
569 match (
570 self.view_stack.last(),
571 self.app.parents.get(&(self.window_id, view_id)),
572 ) {
573 (Some(layout_parent), Some(ParentId::View(app_parent))) => {
574 if layout_parent != app_parent {
575 panic!(
576 "View {} was laid out with parent {} when it was constructed with parent {}",
577 print_error(view_id),
578 print_error(*layout_parent),
579 print_error(*app_parent))
580 }
581 }
582 (None, Some(ParentId::View(app_parent))) => panic!(
583 "View {} was laid out without a parent when it was constructed with parent {}",
584 print_error(view_id),
585 print_error(*app_parent)
586 ),
587 (Some(layout_parent), Some(ParentId::Root)) => panic!(
588 "View {} was laid out with parent {} when it was constructed as a window root",
589 print_error(view_id),
590 print_error(*layout_parent),
591 ),
592 (_, None) => panic!(
593 "View {} did not have a registered parent in the app context",
594 print_error(view_id),
595 ),
596 _ => {}
597 }
598
599 self.view_stack.push(view_id);
600 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
601 let size = rendered_view.layout(constraint, self);
602 self.rendered_views.insert(view_id, rendered_view);
603 self.view_stack.pop();
604 size
605 }
606
607 pub fn render<F, V, T>(&mut self, handle: &ViewHandle<V>, f: F) -> T
608 where
609 F: FnOnce(&mut V, &mut RenderContext<V>) -> T,
610 V: View,
611 {
612 handle.update(self.app, |view, cx| {
613 let mut render_cx = RenderContext {
614 app: cx,
615 window_id: handle.window_id(),
616 view_id: handle.id(),
617 view_type: PhantomData,
618 titlebar_height: self.titlebar_height,
619 hovered_region_ids: self.hovered_region_ids.clone(),
620 clicked_region_ids: self.clicked_region_ids.clone(),
621 refreshing: self.refreshing,
622 };
623 f(view, &mut render_cx)
624 })
625 }
626}
627
628impl<'a> Deref for LayoutContext<'a> {
629 type Target = MutableAppContext;
630
631 fn deref(&self) -> &Self::Target {
632 self.app
633 }
634}
635
636impl<'a> DerefMut for LayoutContext<'a> {
637 fn deref_mut(&mut self) -> &mut Self::Target {
638 self.app
639 }
640}
641
642impl<'a> ReadView for LayoutContext<'a> {
643 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
644 self.app.read_view(handle)
645 }
646}
647
648impl<'a> ReadModel for LayoutContext<'a> {
649 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
650 self.app.read_model(handle)
651 }
652}
653
654impl<'a> UpgradeModelHandle for LayoutContext<'a> {
655 fn upgrade_model_handle<T: Entity>(
656 &self,
657 handle: &WeakModelHandle<T>,
658 ) -> Option<ModelHandle<T>> {
659 self.app.upgrade_model_handle(handle)
660 }
661
662 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
663 self.app.model_handle_is_upgradable(handle)
664 }
665
666 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
667 self.app.upgrade_any_model_handle(handle)
668 }
669}
670
671impl<'a> UpgradeViewHandle for LayoutContext<'a> {
672 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
673 self.app.upgrade_view_handle(handle)
674 }
675
676 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
677 self.app.upgrade_any_view_handle(handle)
678 }
679}
680
681pub struct PaintContext<'a> {
682 rendered_views: &'a mut HashMap<usize, ElementBox>,
683 view_stack: Vec<usize>,
684 pub window_size: Vector2F,
685 pub scene: &'a mut Scene,
686 pub font_cache: &'a FontCache,
687 pub text_layout_cache: &'a TextLayoutCache,
688 pub app: &'a AppContext,
689}
690
691impl<'a> PaintContext<'a> {
692 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
693 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
694 self.view_stack.push(view_id);
695 tree.paint(origin, visible_bounds, self);
696 self.rendered_views.insert(view_id, tree);
697 self.view_stack.pop();
698 }
699 }
700
701 #[inline]
702 pub fn paint_layer<F>(&mut self, clip_bounds: Option<RectF>, f: F)
703 where
704 F: FnOnce(&mut Self),
705 {
706 self.scene.push_layer(clip_bounds);
707 f(self);
708 self.scene.pop_layer();
709 }
710
711 pub fn current_view_id(&self) -> usize {
712 *self.view_stack.last().unwrap()
713 }
714}
715
716impl<'a> Deref for PaintContext<'a> {
717 type Target = AppContext;
718
719 fn deref(&self) -> &Self::Target {
720 self.app
721 }
722}
723
724pub struct EventContext<'a> {
725 rendered_views: &'a mut HashMap<usize, ElementBox>,
726 pub font_cache: &'a FontCache,
727 pub text_layout_cache: &'a TextLayoutCache,
728 pub app: &'a mut MutableAppContext,
729 pub window_id: usize,
730 pub notify_count: usize,
731 view_stack: Vec<usize>,
732 handled: bool,
733 invalidated_views: &'a mut HashSet<usize>,
734}
735
736impl<'a> EventContext<'a> {
737 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
738 if let Some(mut element) = self.rendered_views.remove(&view_id) {
739 let result =
740 self.with_current_view(view_id, |this| element.dispatch_event(event, this));
741 self.rendered_views.insert(view_id, element);
742 result
743 } else {
744 false
745 }
746 }
747
748 fn with_current_view<F, T>(&mut self, view_id: usize, f: F) -> T
749 where
750 F: FnOnce(&mut Self) -> T,
751 {
752 self.view_stack.push(view_id);
753 let result = f(self);
754 self.view_stack.pop();
755 result
756 }
757
758 pub fn window_id(&self) -> usize {
759 self.window_id
760 }
761
762 pub fn view_id(&self) -> Option<usize> {
763 self.view_stack.last().copied()
764 }
765
766 pub fn is_parent_view_focused(&self) -> bool {
767 if let Some(parent_view_id) = self.view_stack.last() {
768 self.app.focused_view_id(self.window_id) == Some(*parent_view_id)
769 } else {
770 false
771 }
772 }
773
774 pub fn focus_parent_view(&mut self) {
775 if let Some(parent_view_id) = self.view_stack.last() {
776 self.app.focus(self.window_id, Some(*parent_view_id))
777 }
778 }
779
780 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
781 self.app
782 .dispatch_any_action_at(self.window_id, *self.view_stack.last().unwrap(), action)
783 }
784
785 pub fn dispatch_action<A: Action>(&mut self, action: A) {
786 self.dispatch_any_action(Box::new(action));
787 }
788
789 pub fn notify(&mut self) {
790 self.notify_count += 1;
791 if let Some(view_id) = self.view_stack.last() {
792 self.invalidated_views.insert(*view_id);
793 }
794 }
795
796 pub fn notify_count(&self) -> usize {
797 self.notify_count
798 }
799
800 pub fn propogate_event(&mut self) {
801 self.handled = false;
802 }
803}
804
805impl<'a> Deref for EventContext<'a> {
806 type Target = MutableAppContext;
807
808 fn deref(&self) -> &Self::Target {
809 self.app
810 }
811}
812
813impl<'a> DerefMut for EventContext<'a> {
814 fn deref_mut(&mut self) -> &mut Self::Target {
815 self.app
816 }
817}
818
819pub struct MeasurementContext<'a> {
820 app: &'a AppContext,
821 rendered_views: &'a HashMap<usize, ElementBox>,
822 pub window_id: usize,
823}
824
825impl<'a> Deref for MeasurementContext<'a> {
826 type Target = AppContext;
827
828 fn deref(&self) -> &Self::Target {
829 self.app
830 }
831}
832
833impl<'a> MeasurementContext<'a> {
834 fn rect_for_text_range(&self, view_id: usize, range_utf16: Range<usize>) -> Option<RectF> {
835 let element = self.rendered_views.get(&view_id)?;
836 element.rect_for_text_range(range_utf16, self)
837 }
838}
839
840pub struct DebugContext<'a> {
841 rendered_views: &'a HashMap<usize, ElementBox>,
842 pub font_cache: &'a FontCache,
843 pub app: &'a AppContext,
844}
845
846#[derive(Clone, Copy, Debug, Eq, PartialEq)]
847pub enum Axis {
848 Horizontal,
849 Vertical,
850}
851
852impl Axis {
853 pub fn invert(self) -> Self {
854 match self {
855 Self::Horizontal => Self::Vertical,
856 Self::Vertical => Self::Horizontal,
857 }
858 }
859}
860
861impl ToJson for Axis {
862 fn to_json(&self) -> serde_json::Value {
863 match self {
864 Axis::Horizontal => json!("horizontal"),
865 Axis::Vertical => json!("vertical"),
866 }
867 }
868}
869
870pub trait Vector2FExt {
871 fn along(self, axis: Axis) -> f32;
872}
873
874impl Vector2FExt for Vector2F {
875 fn along(self, axis: Axis) -> f32 {
876 match axis {
877 Axis::Horizontal => self.x(),
878 Axis::Vertical => self.y(),
879 }
880 }
881}
882
883#[derive(Copy, Clone, Debug)]
884pub struct SizeConstraint {
885 pub min: Vector2F,
886 pub max: Vector2F,
887}
888
889impl SizeConstraint {
890 pub fn new(min: Vector2F, max: Vector2F) -> Self {
891 Self { min, max }
892 }
893
894 pub fn strict(size: Vector2F) -> Self {
895 Self {
896 min: size,
897 max: size,
898 }
899 }
900
901 pub fn strict_along(axis: Axis, max: f32) -> Self {
902 match axis {
903 Axis::Horizontal => Self {
904 min: vec2f(max, 0.0),
905 max: vec2f(max, f32::INFINITY),
906 },
907 Axis::Vertical => Self {
908 min: vec2f(0.0, max),
909 max: vec2f(f32::INFINITY, max),
910 },
911 }
912 }
913
914 pub fn max_along(&self, axis: Axis) -> f32 {
915 match axis {
916 Axis::Horizontal => self.max.x(),
917 Axis::Vertical => self.max.y(),
918 }
919 }
920
921 pub fn min_along(&self, axis: Axis) -> f32 {
922 match axis {
923 Axis::Horizontal => self.min.x(),
924 Axis::Vertical => self.min.y(),
925 }
926 }
927
928 pub fn constrain(&self, size: Vector2F) -> Vector2F {
929 vec2f(
930 size.x().min(self.max.x()).max(self.min.x()),
931 size.y().min(self.max.y()).max(self.min.y()),
932 )
933 }
934}
935
936impl Default for SizeConstraint {
937 fn default() -> Self {
938 SizeConstraint {
939 min: Vector2F::zero(),
940 max: Vector2F::splat(f32::INFINITY),
941 }
942 }
943}
944
945impl ToJson for SizeConstraint {
946 fn to_json(&self) -> serde_json::Value {
947 json!({
948 "min": self.min.to_json(),
949 "max": self.max.to_json(),
950 })
951 }
952}
953
954pub struct ChildView {
955 view: AnyViewHandle,
956}
957
958impl ChildView {
959 pub fn new(view: impl Into<AnyViewHandle>) -> Self {
960 Self { view: view.into() }
961 }
962}
963
964impl Element for ChildView {
965 type LayoutState = ();
966 type PaintState = ();
967
968 fn layout(
969 &mut self,
970 constraint: SizeConstraint,
971 cx: &mut LayoutContext,
972 ) -> (Vector2F, Self::LayoutState) {
973 let size = cx.layout(self.view.id(), constraint);
974 (size, ())
975 }
976
977 fn paint(
978 &mut self,
979 bounds: RectF,
980 visible_bounds: RectF,
981 _: &mut Self::LayoutState,
982 cx: &mut PaintContext,
983 ) -> Self::PaintState {
984 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
985 }
986
987 fn dispatch_event(
988 &mut self,
989 event: &Event,
990 _: RectF,
991 _: RectF,
992 _: &mut Self::LayoutState,
993 _: &mut Self::PaintState,
994 cx: &mut EventContext,
995 ) -> bool {
996 cx.dispatch_event(self.view.id(), event)
997 }
998
999 fn rect_for_text_range(
1000 &self,
1001 range_utf16: Range<usize>,
1002 _: RectF,
1003 _: RectF,
1004 _: &Self::LayoutState,
1005 _: &Self::PaintState,
1006 cx: &MeasurementContext,
1007 ) -> Option<RectF> {
1008 cx.rect_for_text_range(self.view.id(), range_utf16)
1009 }
1010
1011 fn debug(
1012 &self,
1013 bounds: RectF,
1014 _: &Self::LayoutState,
1015 _: &Self::PaintState,
1016 cx: &DebugContext,
1017 ) -> serde_json::Value {
1018 json!({
1019 "type": "ChildView",
1020 "view_id": self.view.id(),
1021 "bounds": bounds.to_json(),
1022 "view": self.view.debug_json(cx.app),
1023 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
1024 view.debug(cx)
1025 } else {
1026 json!(null)
1027 }
1028 })
1029 }
1030}