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, ScrollWheelRegionEvent,
12 UpOutRegionEvent, UpRegionEvent,
13 },
14 text_layout::TextLayoutCache,
15 Action, AnyModelHandle, AnyViewHandle, AnyWeakModelHandle, AssetCache, ElementBox, Entity,
16 FontSystem, ModelHandle, MouseButton, MouseMovedEvent, MouseRegion, MouseRegionId, ParentId,
17 ReadModel, ReadView, RenderContext, RenderParams, Scene, UpgradeModelHandle, UpgradeViewHandle,
18 View, ViewHandle, WeakModelHandle, WeakViewHandle,
19};
20use collections::{HashMap, HashSet};
21use pathfinder_geometry::vector::{vec2f, Vector2F};
22use serde_json::json;
23use smallvec::SmallVec;
24use std::{
25 marker::PhantomData,
26 ops::{Deref, DerefMut, Range},
27 sync::Arc,
28};
29
30pub struct Presenter {
31 window_id: usize,
32 pub(crate) rendered_views: HashMap<usize, ElementBox>,
33 cursor_regions: Vec<CursorRegion>,
34 mouse_regions: Vec<(MouseRegion, usize)>,
35 font_cache: Arc<FontCache>,
36 text_layout_cache: TextLayoutCache,
37 asset_cache: Arc<AssetCache>,
38 last_mouse_moved_event: Option<Event>,
39 hovered_region_ids: HashSet<MouseRegionId>,
40 clicked_region_ids: HashSet<MouseRegionId>,
41 clicked_button: Option<MouseButton>,
42 mouse_position: Vector2F,
43 titlebar_height: f32,
44}
45
46impl Presenter {
47 pub fn new(
48 window_id: usize,
49 titlebar_height: f32,
50 font_cache: Arc<FontCache>,
51 text_layout_cache: TextLayoutCache,
52 asset_cache: Arc<AssetCache>,
53 cx: &mut MutableAppContext,
54 ) -> Self {
55 Self {
56 window_id,
57 rendered_views: cx.render_views(window_id, titlebar_height),
58 cursor_regions: Default::default(),
59 mouse_regions: Default::default(),
60 font_cache,
61 text_layout_cache,
62 asset_cache,
63 last_mouse_moved_event: None,
64 hovered_region_ids: Default::default(),
65 clicked_region_ids: Default::default(),
66 clicked_button: None,
67 mouse_position: vec2f(0., 0.),
68 titlebar_height,
69 }
70 }
71
72 pub fn invalidate(
73 &mut self,
74 invalidation: &mut WindowInvalidation,
75 cx: &mut MutableAppContext,
76 ) {
77 cx.start_frame();
78 for view_id in &invalidation.removed {
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
90 .clicked_button
91 .map(|button| (self.clicked_region_ids.clone(), button)),
92 refreshing: false,
93 })
94 .unwrap(),
95 );
96 }
97 }
98
99 pub fn refresh(&mut self, invalidation: &mut WindowInvalidation, cx: &mut MutableAppContext) {
100 self.invalidate(invalidation, cx);
101 for (view_id, view) in &mut self.rendered_views {
102 if !invalidation.updated.contains(view_id) {
103 *view = cx
104 .render_view(RenderParams {
105 window_id: self.window_id,
106 view_id: *view_id,
107 titlebar_height: self.titlebar_height,
108 hovered_region_ids: self.hovered_region_ids.clone(),
109 clicked_region_ids: self
110 .clicked_button
111 .map(|button| (self.clicked_region_ids.clone(), button)),
112 refreshing: true,
113 })
114 .unwrap();
115 }
116 }
117 }
118
119 pub fn build_scene(
120 &mut self,
121 window_size: Vector2F,
122 scale_factor: f32,
123 refreshing: bool,
124 cx: &mut MutableAppContext,
125 ) -> Scene {
126 let mut scene = Scene::new(scale_factor);
127
128 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
129 self.layout(window_size, refreshing, cx);
130 let mut paint_cx = self.build_paint_context(&mut scene, window_size, cx);
131 paint_cx.paint(
132 root_view_id,
133 Vector2F::zero(),
134 RectF::new(Vector2F::zero(), window_size),
135 );
136 self.text_layout_cache.finish_frame();
137 self.cursor_regions = scene.cursor_regions();
138 self.mouse_regions = scene.mouse_regions();
139
140 if cx.window_is_active(self.window_id) {
141 if let Some(event) = self.last_mouse_moved_event.clone() {
142 self.dispatch_event(event, true, cx);
143 }
144 }
145 } else {
146 log::error!("could not find root_view_id for window {}", self.window_id);
147 }
148
149 scene
150 }
151
152 fn layout(&mut self, window_size: Vector2F, refreshing: bool, cx: &mut MutableAppContext) {
153 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
154 self.build_layout_context(window_size, refreshing, cx)
155 .layout(root_view_id, SizeConstraint::strict(window_size));
156 }
157 }
158
159 pub fn build_layout_context<'a>(
160 &'a mut self,
161 window_size: Vector2F,
162 refreshing: bool,
163 cx: &'a mut MutableAppContext,
164 ) -> LayoutContext<'a> {
165 LayoutContext {
166 window_id: self.window_id,
167 rendered_views: &mut self.rendered_views,
168 font_cache: &self.font_cache,
169 font_system: cx.platform().fonts(),
170 text_layout_cache: &self.text_layout_cache,
171 asset_cache: &self.asset_cache,
172 view_stack: Vec::new(),
173 refreshing,
174 hovered_region_ids: self.hovered_region_ids.clone(),
175 clicked_region_ids: self
176 .clicked_button
177 .map(|button| (self.clicked_region_ids.clone(), button)),
178 titlebar_height: self.titlebar_height,
179 window_size,
180 app: cx,
181 }
182 }
183
184 pub fn build_paint_context<'a>(
185 &'a mut self,
186 scene: &'a mut Scene,
187 window_size: Vector2F,
188 cx: &'a mut MutableAppContext,
189 ) -> PaintContext {
190 PaintContext {
191 scene,
192 window_size,
193 font_cache: &self.font_cache,
194 text_layout_cache: &self.text_layout_cache,
195 rendered_views: &mut self.rendered_views,
196 view_stack: Vec::new(),
197 app: cx,
198 }
199 }
200
201 pub fn rect_for_text_range(&self, range_utf16: Range<usize>, cx: &AppContext) -> Option<RectF> {
202 cx.focused_view_id(self.window_id).and_then(|view_id| {
203 let cx = MeasurementContext {
204 app: cx,
205 rendered_views: &self.rendered_views,
206 window_id: self.window_id,
207 };
208 cx.rect_for_text_range(view_id, range_utf16)
209 })
210 }
211
212 pub fn dispatch_event(
213 &mut self,
214 event: Event,
215 event_reused: bool,
216 cx: &mut MutableAppContext,
217 ) -> bool {
218 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
219 let mut events_to_send = Vec::new();
220
221 // 1. Allocate the correct set of GPUI events generated from the platform events
222 // -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
223 // -> Also moves around mouse related state
224 match &event {
225 Event::MouseDown(e) => {
226 // Click events are weird because they can be fired after a drag event.
227 // MDN says that browsers handle this by starting from 'the most
228 // specific ancestor element that contained both [positions]'
229 // So we need to store the overlapping regions on mouse down.
230
231 // If there is already clicked_button stored, don't replace it.
232 if self.clicked_button.is_none() {
233 self.clicked_region_ids = self
234 .mouse_regions
235 .iter()
236 .filter_map(|(region, _)| {
237 if region.bounds.contains_point(e.position) {
238 Some(region.id())
239 } else {
240 None
241 }
242 })
243 .collect();
244 self.clicked_button = Some(e.button);
245 }
246
247 events_to_send.push(MouseRegionEvent::Down(DownRegionEvent {
248 region: Default::default(),
249 platform_event: e.clone(),
250 }));
251 events_to_send.push(MouseRegionEvent::DownOut(DownOutRegionEvent {
252 region: Default::default(),
253 platform_event: e.clone(),
254 }));
255 }
256 Event::MouseUp(e) => {
257 // NOTE: The order of event pushes is important! MouseUp events MUST be fired
258 // before click events, and so the UpRegionEvent events need to be pushed before
259 // ClickRegionEvents
260 events_to_send.push(MouseRegionEvent::Up(UpRegionEvent {
261 region: Default::default(),
262 platform_event: e.clone(),
263 }));
264 events_to_send.push(MouseRegionEvent::UpOut(UpOutRegionEvent {
265 region: Default::default(),
266 platform_event: e.clone(),
267 }));
268 events_to_send.push(MouseRegionEvent::Click(ClickRegionEvent {
269 region: Default::default(),
270 platform_event: e.clone(),
271 }));
272 }
273 Event::MouseMoved(
274 e @ MouseMovedEvent {
275 position,
276 pressed_button,
277 ..
278 },
279 ) => {
280 let mut style_to_assign = CursorStyle::Arrow;
281 for region in self.cursor_regions.iter().rev() {
282 if region.bounds.contains_point(*position) {
283 style_to_assign = region.style;
284 break;
285 }
286 }
287 cx.platform().set_cursor_style(style_to_assign);
288
289 if !event_reused {
290 if pressed_button.is_some() {
291 events_to_send.push(MouseRegionEvent::Drag(DragRegionEvent {
292 region: Default::default(),
293 prev_mouse_position: self.mouse_position,
294 platform_event: e.clone(),
295 }));
296 } else if let Some(clicked_button) = self.clicked_button {
297 // Mouse up event happened outside the current window. Simulate mouse up button event
298 let button_event = e.to_button_event(clicked_button);
299 events_to_send.push(MouseRegionEvent::Up(UpRegionEvent {
300 region: Default::default(),
301 platform_event: button_event.clone(),
302 }));
303 events_to_send.push(MouseRegionEvent::UpOut(UpOutRegionEvent {
304 region: Default::default(),
305 platform_event: button_event.clone(),
306 }));
307 events_to_send.push(MouseRegionEvent::Click(ClickRegionEvent {
308 region: Default::default(),
309 platform_event: button_event.clone(),
310 }));
311 }
312
313 events_to_send.push(MouseRegionEvent::Move(MoveRegionEvent {
314 region: Default::default(),
315 platform_event: e.clone(),
316 }));
317 }
318
319 events_to_send.push(MouseRegionEvent::Hover(HoverRegionEvent {
320 region: Default::default(),
321 platform_event: e.clone(),
322 started: false,
323 }));
324
325 self.last_mouse_moved_event = Some(event.clone());
326 }
327 Event::ScrollWheel(e) => {
328 events_to_send.push(MouseRegionEvent::ScrollWheel(ScrollWheelRegionEvent {
329 region: Default::default(),
330 platform_event: e.clone(),
331 }))
332 }
333
334 _ => {}
335 }
336
337 if let Some(position) = event.position() {
338 self.mouse_position = position;
339 }
340
341 let mut invalidated_views: HashSet<usize> = Default::default();
342 let mut any_event_handled = false;
343 // 2. Process the raw mouse events into region events
344 for mut region_event in events_to_send {
345 let mut valid_regions = Vec::new();
346
347 // GPUI elements are arranged by depth but sibling elements can register overlapping
348 // mouse regions. As such, hover events are only fired on overlapping elements which
349 // are at the same depth as the topmost element which overlaps with the mouse.
350
351 match ®ion_event {
352 MouseRegionEvent::Hover(_) => {
353 let mut top_most_depth = None;
354 let mouse_position = self.mouse_position.clone();
355 for (region, depth) in self.mouse_regions.iter().rev() {
356 // Allow mouse regions to appear transparent to hovers
357 if !region.hoverable {
358 continue;
359 }
360
361 let contains_mouse = region.bounds.contains_point(mouse_position);
362
363 if contains_mouse && top_most_depth.is_none() {
364 top_most_depth = Some(depth);
365 }
366
367 // This unwrap relies on short circuiting boolean expressions
368 // The right side of the && is only executed when contains_mouse
369 // is true, and we know above that when contains_mouse is true
370 // top_most_depth is set
371 if contains_mouse && depth == top_most_depth.unwrap() {
372 //Ensure that hover entrance events aren't sent twice
373 if self.hovered_region_ids.insert(region.id()) {
374 valid_regions.push(region.clone());
375 invalidated_views.insert(region.id().view_id());
376 }
377 } else {
378 // Ensure that hover exit events aren't sent twice
379 if self.hovered_region_ids.remove(®ion.id()) {
380 valid_regions.push(region.clone());
381 invalidated_views.insert(region.id().view_id());
382 }
383 }
384 }
385 }
386 MouseRegionEvent::Click(e) => {
387 // Only raise click events if the released button is the same as the one stored
388 if self
389 .clicked_button
390 .map(|clicked_button| clicked_button == e.button)
391 .unwrap_or(false)
392 {
393 // Clear clicked regions and clicked button
394 let clicked_region_ids =
395 std::mem::replace(&mut self.clicked_region_ids, Default::default());
396 self.clicked_button = None;
397
398 // Find regions which still overlap with the mouse since the last MouseDown happened
399 for (mouse_region, _) in self.mouse_regions.iter().rev() {
400 if clicked_region_ids.contains(&mouse_region.id()) {
401 valid_regions.push(mouse_region.clone());
402 }
403 }
404 }
405 }
406 MouseRegionEvent::Drag(_) => {
407 for (mouse_region, _) in self.mouse_regions.iter().rev() {
408 if self.clicked_region_ids.contains(&mouse_region.id()) {
409 valid_regions.push(mouse_region.clone());
410 }
411 }
412 }
413
414 MouseRegionEvent::UpOut(_) | MouseRegionEvent::DownOut(_) => {
415 for (mouse_region, _) in self.mouse_regions.iter().rev() {
416 // NOT contains
417 if !mouse_region.bounds.contains_point(self.mouse_position) {
418 valid_regions.push(mouse_region.clone());
419 }
420 }
421 }
422 _ => {
423 for (mouse_region, _) in self.mouse_regions.iter().rev() {
424 // Contains
425 if mouse_region.bounds.contains_point(self.mouse_position) {
426 valid_regions.push(mouse_region.clone());
427 }
428 }
429 }
430 }
431
432 //3. Fire region events
433 let hovered_region_ids = self.hovered_region_ids.clone();
434 for valid_region in valid_regions.into_iter() {
435 let mut event_cx = self.build_event_context(&mut invalidated_views, cx);
436
437 region_event.set_region(valid_region.bounds);
438 if let MouseRegionEvent::Hover(e) = &mut region_event {
439 e.started = hovered_region_ids.contains(&valid_region.id())
440 }
441 // Handle Down events if the MouseRegion has a Click handler. This makes the api more intuitive as you would
442 // not expect a MouseRegion to be transparent to Down events if it also has a Click handler.
443 // This behavior can be overridden by adding a Down handler that calls cx.propogate_event
444 if let MouseRegionEvent::Down(e) = ®ion_event {
445 if valid_region
446 .handlers
447 .contains_handler(MouseRegionEvent::click_disc(), Some(e.button))
448 {
449 event_cx.handled = true;
450 }
451 }
452
453 if let Some(callback) = valid_region.handlers.get(®ion_event.handler_key()) {
454 event_cx.handled = true;
455 event_cx
456 .invalidated_views
457 .insert(valid_region.id().view_id());
458 event_cx.with_current_view(valid_region.id().view_id(), {
459 let region_event = region_event.clone();
460 |cx| {
461 callback(region_event, cx);
462 }
463 });
464 }
465
466 any_event_handled = any_event_handled || event_cx.handled;
467 // For bubbling events, if the event was handled, don't continue dispatching
468 // This only makes sense for local events.
469 if event_cx.handled && region_event.is_capturable() {
470 break;
471 }
472 }
473 }
474
475 if !any_event_handled && !event_reused {
476 let mut event_cx = self.build_event_context(&mut invalidated_views, cx);
477 any_event_handled = event_cx.dispatch_event(root_view_id, &event);
478 }
479
480 for view_id in invalidated_views {
481 cx.notify_view(self.window_id, view_id);
482 }
483
484 any_event_handled
485 } else {
486 false
487 }
488 }
489
490 pub fn build_event_context<'a>(
491 &'a mut self,
492 invalidated_views: &'a mut HashSet<usize>,
493 cx: &'a mut MutableAppContext,
494 ) -> EventContext<'a> {
495 EventContext {
496 rendered_views: &mut self.rendered_views,
497 font_cache: &self.font_cache,
498 text_layout_cache: &self.text_layout_cache,
499 view_stack: Default::default(),
500 invalidated_views,
501 notify_count: 0,
502 handled: false,
503 window_id: self.window_id,
504 app: cx,
505 }
506 }
507
508 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
509 let view = cx.root_view(self.window_id)?;
510 Some(json!({
511 "root_view": view.debug_json(cx),
512 "root_element": self.rendered_views.get(&view.id())
513 .map(|root_element| {
514 root_element.debug(&DebugContext {
515 rendered_views: &self.rendered_views,
516 font_cache: &self.font_cache,
517 app: cx,
518 })
519 })
520 }))
521 }
522}
523
524pub struct LayoutContext<'a> {
525 window_id: usize,
526 rendered_views: &'a mut HashMap<usize, ElementBox>,
527 view_stack: Vec<usize>,
528 pub font_cache: &'a Arc<FontCache>,
529 pub font_system: Arc<dyn FontSystem>,
530 pub text_layout_cache: &'a TextLayoutCache,
531 pub asset_cache: &'a AssetCache,
532 pub app: &'a mut MutableAppContext,
533 pub refreshing: bool,
534 pub window_size: Vector2F,
535 titlebar_height: f32,
536 hovered_region_ids: HashSet<MouseRegionId>,
537 clicked_region_ids: Option<(HashSet<MouseRegionId>, MouseButton)>,
538}
539
540impl<'a> LayoutContext<'a> {
541 pub(crate) fn keystrokes_for_action(
542 &self,
543 action: &dyn Action,
544 ) -> Option<SmallVec<[Keystroke; 2]>> {
545 self.app
546 .keystrokes_for_action(self.window_id, &self.view_stack, action)
547 }
548
549 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
550 let print_error = |view_id| {
551 format!(
552 "{} with id {}",
553 self.app.name_for_view(self.window_id, view_id).unwrap(),
554 view_id,
555 )
556 };
557 match (
558 self.view_stack.last(),
559 self.app.parents.get(&(self.window_id, view_id)),
560 ) {
561 (Some(layout_parent), Some(ParentId::View(app_parent))) => {
562 if layout_parent != app_parent {
563 panic!(
564 "View {} was laid out with parent {} when it was constructed with parent {}",
565 print_error(view_id),
566 print_error(*layout_parent),
567 print_error(*app_parent))
568 }
569 }
570 (None, Some(ParentId::View(app_parent))) => panic!(
571 "View {} was laid out without a parent when it was constructed with parent {}",
572 print_error(view_id),
573 print_error(*app_parent)
574 ),
575 (Some(layout_parent), Some(ParentId::Root)) => panic!(
576 "View {} was laid out with parent {} when it was constructed as a window root",
577 print_error(view_id),
578 print_error(*layout_parent),
579 ),
580 (_, None) => panic!(
581 "View {} did not have a registered parent in the app context",
582 print_error(view_id),
583 ),
584 _ => {}
585 }
586
587 self.view_stack.push(view_id);
588 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
589 let size = rendered_view.layout(constraint, self);
590 self.rendered_views.insert(view_id, rendered_view);
591 self.view_stack.pop();
592 size
593 }
594
595 pub fn render<F, V, T>(&mut self, handle: &ViewHandle<V>, f: F) -> T
596 where
597 F: FnOnce(&mut V, &mut RenderContext<V>) -> T,
598 V: View,
599 {
600 handle.update(self.app, |view, cx| {
601 let mut render_cx = RenderContext {
602 app: cx,
603 window_id: handle.window_id(),
604 view_id: handle.id(),
605 view_type: PhantomData,
606 titlebar_height: self.titlebar_height,
607 hovered_region_ids: self.hovered_region_ids.clone(),
608 clicked_region_ids: self.clicked_region_ids.clone(),
609 refreshing: self.refreshing,
610 };
611 f(view, &mut render_cx)
612 })
613 }
614}
615
616impl<'a> Deref for LayoutContext<'a> {
617 type Target = MutableAppContext;
618
619 fn deref(&self) -> &Self::Target {
620 self.app
621 }
622}
623
624impl<'a> DerefMut for LayoutContext<'a> {
625 fn deref_mut(&mut self) -> &mut Self::Target {
626 self.app
627 }
628}
629
630impl<'a> ReadView for LayoutContext<'a> {
631 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
632 self.app.read_view(handle)
633 }
634}
635
636impl<'a> ReadModel for LayoutContext<'a> {
637 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
638 self.app.read_model(handle)
639 }
640}
641
642impl<'a> UpgradeModelHandle for LayoutContext<'a> {
643 fn upgrade_model_handle<T: Entity>(
644 &self,
645 handle: &WeakModelHandle<T>,
646 ) -> Option<ModelHandle<T>> {
647 self.app.upgrade_model_handle(handle)
648 }
649
650 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
651 self.app.model_handle_is_upgradable(handle)
652 }
653
654 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
655 self.app.upgrade_any_model_handle(handle)
656 }
657}
658
659impl<'a> UpgradeViewHandle for LayoutContext<'a> {
660 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
661 self.app.upgrade_view_handle(handle)
662 }
663
664 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
665 self.app.upgrade_any_view_handle(handle)
666 }
667}
668
669pub struct PaintContext<'a> {
670 rendered_views: &'a mut HashMap<usize, ElementBox>,
671 view_stack: Vec<usize>,
672 pub window_size: Vector2F,
673 pub scene: &'a mut Scene,
674 pub font_cache: &'a FontCache,
675 pub text_layout_cache: &'a TextLayoutCache,
676 pub app: &'a AppContext,
677}
678
679impl<'a> PaintContext<'a> {
680 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
681 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
682 self.view_stack.push(view_id);
683 tree.paint(origin, visible_bounds, self);
684 self.rendered_views.insert(view_id, tree);
685 self.view_stack.pop();
686 }
687 }
688
689 #[inline]
690 pub fn paint_layer<F>(&mut self, clip_bounds: Option<RectF>, f: F)
691 where
692 F: FnOnce(&mut Self),
693 {
694 self.scene.push_layer(clip_bounds);
695 f(self);
696 self.scene.pop_layer();
697 }
698
699 pub fn current_view_id(&self) -> usize {
700 *self.view_stack.last().unwrap()
701 }
702}
703
704impl<'a> Deref for PaintContext<'a> {
705 type Target = AppContext;
706
707 fn deref(&self) -> &Self::Target {
708 self.app
709 }
710}
711
712pub struct EventContext<'a> {
713 rendered_views: &'a mut HashMap<usize, ElementBox>,
714 pub font_cache: &'a FontCache,
715 pub text_layout_cache: &'a TextLayoutCache,
716 pub app: &'a mut MutableAppContext,
717 pub window_id: usize,
718 pub notify_count: usize,
719 view_stack: Vec<usize>,
720 handled: bool,
721 invalidated_views: &'a mut HashSet<usize>,
722}
723
724impl<'a> EventContext<'a> {
725 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
726 if let Some(mut element) = self.rendered_views.remove(&view_id) {
727 let result =
728 self.with_current_view(view_id, |this| element.dispatch_event(event, this));
729 self.rendered_views.insert(view_id, element);
730 result
731 } else {
732 false
733 }
734 }
735
736 fn with_current_view<F, T>(&mut self, view_id: usize, f: F) -> T
737 where
738 F: FnOnce(&mut Self) -> T,
739 {
740 self.view_stack.push(view_id);
741 let result = f(self);
742 self.view_stack.pop();
743 result
744 }
745
746 pub fn window_id(&self) -> usize {
747 self.window_id
748 }
749
750 pub fn view_id(&self) -> Option<usize> {
751 self.view_stack.last().copied()
752 }
753
754 pub fn is_parent_view_focused(&self) -> bool {
755 if let Some(parent_view_id) = self.view_stack.last() {
756 self.app.focused_view_id(self.window_id) == Some(*parent_view_id)
757 } else {
758 false
759 }
760 }
761
762 pub fn focus_parent_view(&mut self) {
763 if let Some(parent_view_id) = self.view_stack.last() {
764 self.app.focus(self.window_id, Some(*parent_view_id))
765 }
766 }
767
768 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
769 self.app
770 .dispatch_any_action_at(self.window_id, *self.view_stack.last().unwrap(), action)
771 }
772
773 pub fn dispatch_action<A: Action>(&mut self, action: A) {
774 self.dispatch_any_action(Box::new(action));
775 }
776
777 pub fn notify(&mut self) {
778 self.notify_count += 1;
779 if let Some(view_id) = self.view_stack.last() {
780 self.invalidated_views.insert(*view_id);
781 }
782 }
783
784 pub fn notify_count(&self) -> usize {
785 self.notify_count
786 }
787
788 pub fn propogate_event(&mut self) {
789 self.handled = false;
790 }
791}
792
793impl<'a> Deref for EventContext<'a> {
794 type Target = MutableAppContext;
795
796 fn deref(&self) -> &Self::Target {
797 self.app
798 }
799}
800
801impl<'a> DerefMut for EventContext<'a> {
802 fn deref_mut(&mut self) -> &mut Self::Target {
803 self.app
804 }
805}
806
807pub struct MeasurementContext<'a> {
808 app: &'a AppContext,
809 rendered_views: &'a HashMap<usize, ElementBox>,
810 pub window_id: usize,
811}
812
813impl<'a> Deref for MeasurementContext<'a> {
814 type Target = AppContext;
815
816 fn deref(&self) -> &Self::Target {
817 self.app
818 }
819}
820
821impl<'a> MeasurementContext<'a> {
822 fn rect_for_text_range(&self, view_id: usize, range_utf16: Range<usize>) -> Option<RectF> {
823 let element = self.rendered_views.get(&view_id)?;
824 element.rect_for_text_range(range_utf16, self)
825 }
826}
827
828pub struct DebugContext<'a> {
829 rendered_views: &'a HashMap<usize, ElementBox>,
830 pub font_cache: &'a FontCache,
831 pub app: &'a AppContext,
832}
833
834#[derive(Clone, Copy, Debug, Eq, PartialEq)]
835pub enum Axis {
836 Horizontal,
837 Vertical,
838}
839
840impl Axis {
841 pub fn invert(self) -> Self {
842 match self {
843 Self::Horizontal => Self::Vertical,
844 Self::Vertical => Self::Horizontal,
845 }
846 }
847}
848
849impl ToJson for Axis {
850 fn to_json(&self) -> serde_json::Value {
851 match self {
852 Axis::Horizontal => json!("horizontal"),
853 Axis::Vertical => json!("vertical"),
854 }
855 }
856}
857
858pub trait Vector2FExt {
859 fn along(self, axis: Axis) -> f32;
860}
861
862impl Vector2FExt for Vector2F {
863 fn along(self, axis: Axis) -> f32 {
864 match axis {
865 Axis::Horizontal => self.x(),
866 Axis::Vertical => self.y(),
867 }
868 }
869}
870
871#[derive(Copy, Clone, Debug)]
872pub struct SizeConstraint {
873 pub min: Vector2F,
874 pub max: Vector2F,
875}
876
877impl SizeConstraint {
878 pub fn new(min: Vector2F, max: Vector2F) -> Self {
879 Self { min, max }
880 }
881
882 pub fn strict(size: Vector2F) -> Self {
883 Self {
884 min: size,
885 max: size,
886 }
887 }
888
889 pub fn strict_along(axis: Axis, max: f32) -> Self {
890 match axis {
891 Axis::Horizontal => Self {
892 min: vec2f(max, 0.0),
893 max: vec2f(max, f32::INFINITY),
894 },
895 Axis::Vertical => Self {
896 min: vec2f(0.0, max),
897 max: vec2f(f32::INFINITY, max),
898 },
899 }
900 }
901
902 pub fn max_along(&self, axis: Axis) -> f32 {
903 match axis {
904 Axis::Horizontal => self.max.x(),
905 Axis::Vertical => self.max.y(),
906 }
907 }
908
909 pub fn min_along(&self, axis: Axis) -> f32 {
910 match axis {
911 Axis::Horizontal => self.min.x(),
912 Axis::Vertical => self.min.y(),
913 }
914 }
915
916 pub fn constrain(&self, size: Vector2F) -> Vector2F {
917 vec2f(
918 size.x().min(self.max.x()).max(self.min.x()),
919 size.y().min(self.max.y()).max(self.min.y()),
920 )
921 }
922}
923
924impl Default for SizeConstraint {
925 fn default() -> Self {
926 SizeConstraint {
927 min: Vector2F::zero(),
928 max: Vector2F::splat(f32::INFINITY),
929 }
930 }
931}
932
933impl ToJson for SizeConstraint {
934 fn to_json(&self) -> serde_json::Value {
935 json!({
936 "min": self.min.to_json(),
937 "max": self.max.to_json(),
938 })
939 }
940}
941
942pub struct ChildView {
943 view: AnyViewHandle,
944}
945
946impl ChildView {
947 pub fn new(view: impl Into<AnyViewHandle>) -> Self {
948 Self { view: view.into() }
949 }
950}
951
952impl Element for ChildView {
953 type LayoutState = ();
954 type PaintState = ();
955
956 fn layout(
957 &mut self,
958 constraint: SizeConstraint,
959 cx: &mut LayoutContext,
960 ) -> (Vector2F, Self::LayoutState) {
961 let size = cx.layout(self.view.id(), constraint);
962 (size, ())
963 }
964
965 fn paint(
966 &mut self,
967 bounds: RectF,
968 visible_bounds: RectF,
969 _: &mut Self::LayoutState,
970 cx: &mut PaintContext,
971 ) -> Self::PaintState {
972 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
973 }
974
975 fn dispatch_event(
976 &mut self,
977 event: &Event,
978 _: RectF,
979 _: RectF,
980 _: &mut Self::LayoutState,
981 _: &mut Self::PaintState,
982 cx: &mut EventContext,
983 ) -> bool {
984 cx.dispatch_event(self.view.id(), event)
985 }
986
987 fn rect_for_text_range(
988 &self,
989 range_utf16: Range<usize>,
990 _: RectF,
991 _: RectF,
992 _: &Self::LayoutState,
993 _: &Self::PaintState,
994 cx: &MeasurementContext,
995 ) -> Option<RectF> {
996 cx.rect_for_text_range(self.view.id(), range_utf16)
997 }
998
999 fn debug(
1000 &self,
1001 bounds: RectF,
1002 _: &Self::LayoutState,
1003 _: &Self::PaintState,
1004 cx: &DebugContext,
1005 ) -> serde_json::Value {
1006 json!({
1007 "type": "ChildView",
1008 "view_id": self.view.id(),
1009 "bounds": bounds.to_json(),
1010 "view": self.view.debug_json(cx.app),
1011 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
1012 view.debug(cx)
1013 } else {
1014 json!(null)
1015 }
1016 })
1017 }
1018}