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.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.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.invalidated_views.insert(valid_region.view_id);
456 event_cx.with_current_view(valid_region.view_id, {
457 let region_event = region_event.clone();
458 |cx| {
459 callback(region_event, cx);
460 }
461 });
462 }
463
464 any_event_handled = any_event_handled || event_cx.handled;
465 // For bubbling events, if the event was handled, don't continue dispatching
466 // This only makes sense for local events.
467 if event_cx.handled && region_event.is_capturable() {
468 break;
469 }
470 }
471 }
472
473 if !any_event_handled && !event_reused {
474 let mut event_cx = self.build_event_context(&mut invalidated_views, cx);
475 any_event_handled = event_cx.dispatch_event(root_view_id, &event);
476 }
477
478 for view_id in invalidated_views {
479 cx.notify_view(self.window_id, view_id);
480 }
481
482 any_event_handled
483 } else {
484 false
485 }
486 }
487
488 pub fn build_event_context<'a>(
489 &'a mut self,
490 invalidated_views: &'a mut HashSet<usize>,
491 cx: &'a mut MutableAppContext,
492 ) -> EventContext<'a> {
493 EventContext {
494 rendered_views: &mut self.rendered_views,
495 font_cache: &self.font_cache,
496 text_layout_cache: &self.text_layout_cache,
497 view_stack: Default::default(),
498 invalidated_views,
499 notify_count: 0,
500 handled: false,
501 window_id: self.window_id,
502 app: cx,
503 }
504 }
505
506 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
507 let view = cx.root_view(self.window_id)?;
508 Some(json!({
509 "root_view": view.debug_json(cx),
510 "root_element": self.rendered_views.get(&view.id())
511 .map(|root_element| {
512 root_element.debug(&DebugContext {
513 rendered_views: &self.rendered_views,
514 font_cache: &self.font_cache,
515 app: cx,
516 })
517 })
518 }))
519 }
520}
521
522pub struct LayoutContext<'a> {
523 window_id: usize,
524 rendered_views: &'a mut HashMap<usize, ElementBox>,
525 view_stack: Vec<usize>,
526 pub font_cache: &'a Arc<FontCache>,
527 pub font_system: Arc<dyn FontSystem>,
528 pub text_layout_cache: &'a TextLayoutCache,
529 pub asset_cache: &'a AssetCache,
530 pub app: &'a mut MutableAppContext,
531 pub refreshing: bool,
532 pub window_size: Vector2F,
533 titlebar_height: f32,
534 hovered_region_ids: HashSet<MouseRegionId>,
535 clicked_region_ids: Option<(HashSet<MouseRegionId>, MouseButton)>,
536}
537
538impl<'a> LayoutContext<'a> {
539 pub(crate) fn keystrokes_for_action(
540 &self,
541 action: &dyn Action,
542 ) -> Option<SmallVec<[Keystroke; 2]>> {
543 self.app
544 .keystrokes_for_action(self.window_id, &self.view_stack, action)
545 }
546
547 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
548 let print_error = |view_id| {
549 format!(
550 "{} with id {}",
551 self.app.name_for_view(self.window_id, view_id).unwrap(),
552 view_id,
553 )
554 };
555 match (
556 self.view_stack.last(),
557 self.app.parents.get(&(self.window_id, view_id)),
558 ) {
559 (Some(layout_parent), Some(ParentId::View(app_parent))) => {
560 if layout_parent != app_parent {
561 panic!(
562 "View {} was laid out with parent {} when it was constructed with parent {}",
563 print_error(view_id),
564 print_error(*layout_parent),
565 print_error(*app_parent))
566 }
567 }
568 (None, Some(ParentId::View(app_parent))) => panic!(
569 "View {} was laid out without a parent when it was constructed with parent {}",
570 print_error(view_id),
571 print_error(*app_parent)
572 ),
573 (Some(layout_parent), Some(ParentId::Root)) => panic!(
574 "View {} was laid out with parent {} when it was constructed as a window root",
575 print_error(view_id),
576 print_error(*layout_parent),
577 ),
578 (_, None) => panic!(
579 "View {} did not have a registered parent in the app context",
580 print_error(view_id),
581 ),
582 _ => {}
583 }
584
585 self.view_stack.push(view_id);
586 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
587 let size = rendered_view.layout(constraint, self);
588 self.rendered_views.insert(view_id, rendered_view);
589 self.view_stack.pop();
590 size
591 }
592
593 pub fn render<F, V, T>(&mut self, handle: &ViewHandle<V>, f: F) -> T
594 where
595 F: FnOnce(&mut V, &mut RenderContext<V>) -> T,
596 V: View,
597 {
598 handle.update(self.app, |view, cx| {
599 let mut render_cx = RenderContext {
600 app: cx,
601 window_id: handle.window_id(),
602 view_id: handle.id(),
603 view_type: PhantomData,
604 titlebar_height: self.titlebar_height,
605 hovered_region_ids: self.hovered_region_ids.clone(),
606 clicked_region_ids: self.clicked_region_ids.clone(),
607 refreshing: self.refreshing,
608 };
609 f(view, &mut render_cx)
610 })
611 }
612}
613
614impl<'a> Deref for LayoutContext<'a> {
615 type Target = MutableAppContext;
616
617 fn deref(&self) -> &Self::Target {
618 self.app
619 }
620}
621
622impl<'a> DerefMut for LayoutContext<'a> {
623 fn deref_mut(&mut self) -> &mut Self::Target {
624 self.app
625 }
626}
627
628impl<'a> ReadView for LayoutContext<'a> {
629 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
630 self.app.read_view(handle)
631 }
632}
633
634impl<'a> ReadModel for LayoutContext<'a> {
635 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
636 self.app.read_model(handle)
637 }
638}
639
640impl<'a> UpgradeModelHandle for LayoutContext<'a> {
641 fn upgrade_model_handle<T: Entity>(
642 &self,
643 handle: &WeakModelHandle<T>,
644 ) -> Option<ModelHandle<T>> {
645 self.app.upgrade_model_handle(handle)
646 }
647
648 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
649 self.app.model_handle_is_upgradable(handle)
650 }
651
652 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
653 self.app.upgrade_any_model_handle(handle)
654 }
655}
656
657impl<'a> UpgradeViewHandle for LayoutContext<'a> {
658 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
659 self.app.upgrade_view_handle(handle)
660 }
661
662 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
663 self.app.upgrade_any_view_handle(handle)
664 }
665}
666
667pub struct PaintContext<'a> {
668 rendered_views: &'a mut HashMap<usize, ElementBox>,
669 view_stack: Vec<usize>,
670 pub window_size: Vector2F,
671 pub scene: &'a mut Scene,
672 pub font_cache: &'a FontCache,
673 pub text_layout_cache: &'a TextLayoutCache,
674 pub app: &'a AppContext,
675}
676
677impl<'a> PaintContext<'a> {
678 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
679 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
680 self.view_stack.push(view_id);
681 tree.paint(origin, visible_bounds, self);
682 self.rendered_views.insert(view_id, tree);
683 self.view_stack.pop();
684 }
685 }
686
687 #[inline]
688 pub fn paint_layer<F>(&mut self, clip_bounds: Option<RectF>, f: F)
689 where
690 F: FnOnce(&mut Self),
691 {
692 self.scene.push_layer(clip_bounds);
693 f(self);
694 self.scene.pop_layer();
695 }
696
697 pub fn current_view_id(&self) -> usize {
698 *self.view_stack.last().unwrap()
699 }
700}
701
702impl<'a> Deref for PaintContext<'a> {
703 type Target = AppContext;
704
705 fn deref(&self) -> &Self::Target {
706 self.app
707 }
708}
709
710pub struct EventContext<'a> {
711 rendered_views: &'a mut HashMap<usize, ElementBox>,
712 pub font_cache: &'a FontCache,
713 pub text_layout_cache: &'a TextLayoutCache,
714 pub app: &'a mut MutableAppContext,
715 pub window_id: usize,
716 pub notify_count: usize,
717 view_stack: Vec<usize>,
718 handled: bool,
719 invalidated_views: &'a mut HashSet<usize>,
720}
721
722impl<'a> EventContext<'a> {
723 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
724 if let Some(mut element) = self.rendered_views.remove(&view_id) {
725 let result =
726 self.with_current_view(view_id, |this| element.dispatch_event(event, this));
727 self.rendered_views.insert(view_id, element);
728 result
729 } else {
730 false
731 }
732 }
733
734 fn with_current_view<F, T>(&mut self, view_id: usize, f: F) -> T
735 where
736 F: FnOnce(&mut Self) -> T,
737 {
738 self.view_stack.push(view_id);
739 let result = f(self);
740 self.view_stack.pop();
741 result
742 }
743
744 pub fn window_id(&self) -> usize {
745 self.window_id
746 }
747
748 pub fn view_id(&self) -> Option<usize> {
749 self.view_stack.last().copied()
750 }
751
752 pub fn is_parent_view_focused(&self) -> bool {
753 if let Some(parent_view_id) = self.view_stack.last() {
754 self.app.focused_view_id(self.window_id) == Some(*parent_view_id)
755 } else {
756 false
757 }
758 }
759
760 pub fn focus_parent_view(&mut self) {
761 if let Some(parent_view_id) = self.view_stack.last() {
762 self.app.focus(self.window_id, Some(*parent_view_id))
763 }
764 }
765
766 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
767 self.app
768 .dispatch_any_action_at(self.window_id, *self.view_stack.last().unwrap(), action)
769 }
770
771 pub fn dispatch_action<A: Action>(&mut self, action: A) {
772 self.dispatch_any_action(Box::new(action));
773 }
774
775 pub fn notify(&mut self) {
776 self.notify_count += 1;
777 if let Some(view_id) = self.view_stack.last() {
778 self.invalidated_views.insert(*view_id);
779 }
780 }
781
782 pub fn notify_count(&self) -> usize {
783 self.notify_count
784 }
785
786 pub fn propogate_event(&mut self) {
787 self.handled = false;
788 }
789}
790
791impl<'a> Deref for EventContext<'a> {
792 type Target = MutableAppContext;
793
794 fn deref(&self) -> &Self::Target {
795 self.app
796 }
797}
798
799impl<'a> DerefMut for EventContext<'a> {
800 fn deref_mut(&mut self) -> &mut Self::Target {
801 self.app
802 }
803}
804
805pub struct MeasurementContext<'a> {
806 app: &'a AppContext,
807 rendered_views: &'a HashMap<usize, ElementBox>,
808 pub window_id: usize,
809}
810
811impl<'a> Deref for MeasurementContext<'a> {
812 type Target = AppContext;
813
814 fn deref(&self) -> &Self::Target {
815 self.app
816 }
817}
818
819impl<'a> MeasurementContext<'a> {
820 fn rect_for_text_range(&self, view_id: usize, range_utf16: Range<usize>) -> Option<RectF> {
821 let element = self.rendered_views.get(&view_id)?;
822 element.rect_for_text_range(range_utf16, self)
823 }
824}
825
826pub struct DebugContext<'a> {
827 rendered_views: &'a HashMap<usize, ElementBox>,
828 pub font_cache: &'a FontCache,
829 pub app: &'a AppContext,
830}
831
832#[derive(Clone, Copy, Debug, Eq, PartialEq)]
833pub enum Axis {
834 Horizontal,
835 Vertical,
836}
837
838impl Axis {
839 pub fn invert(self) -> Self {
840 match self {
841 Self::Horizontal => Self::Vertical,
842 Self::Vertical => Self::Horizontal,
843 }
844 }
845}
846
847impl ToJson for Axis {
848 fn to_json(&self) -> serde_json::Value {
849 match self {
850 Axis::Horizontal => json!("horizontal"),
851 Axis::Vertical => json!("vertical"),
852 }
853 }
854}
855
856pub trait Vector2FExt {
857 fn along(self, axis: Axis) -> f32;
858}
859
860impl Vector2FExt for Vector2F {
861 fn along(self, axis: Axis) -> f32 {
862 match axis {
863 Axis::Horizontal => self.x(),
864 Axis::Vertical => self.y(),
865 }
866 }
867}
868
869#[derive(Copy, Clone, Debug)]
870pub struct SizeConstraint {
871 pub min: Vector2F,
872 pub max: Vector2F,
873}
874
875impl SizeConstraint {
876 pub fn new(min: Vector2F, max: Vector2F) -> Self {
877 Self { min, max }
878 }
879
880 pub fn strict(size: Vector2F) -> Self {
881 Self {
882 min: size,
883 max: size,
884 }
885 }
886
887 pub fn strict_along(axis: Axis, max: f32) -> Self {
888 match axis {
889 Axis::Horizontal => Self {
890 min: vec2f(max, 0.0),
891 max: vec2f(max, f32::INFINITY),
892 },
893 Axis::Vertical => Self {
894 min: vec2f(0.0, max),
895 max: vec2f(f32::INFINITY, max),
896 },
897 }
898 }
899
900 pub fn max_along(&self, axis: Axis) -> f32 {
901 match axis {
902 Axis::Horizontal => self.max.x(),
903 Axis::Vertical => self.max.y(),
904 }
905 }
906
907 pub fn min_along(&self, axis: Axis) -> f32 {
908 match axis {
909 Axis::Horizontal => self.min.x(),
910 Axis::Vertical => self.min.y(),
911 }
912 }
913
914 pub fn constrain(&self, size: Vector2F) -> Vector2F {
915 vec2f(
916 size.x().min(self.max.x()).max(self.min.x()),
917 size.y().min(self.max.y()).max(self.min.y()),
918 )
919 }
920}
921
922impl Default for SizeConstraint {
923 fn default() -> Self {
924 SizeConstraint {
925 min: Vector2F::zero(),
926 max: Vector2F::splat(f32::INFINITY),
927 }
928 }
929}
930
931impl ToJson for SizeConstraint {
932 fn to_json(&self) -> serde_json::Value {
933 json!({
934 "min": self.min.to_json(),
935 "max": self.max.to_json(),
936 })
937 }
938}
939
940pub struct ChildView {
941 view: AnyViewHandle,
942}
943
944impl ChildView {
945 pub fn new(view: impl Into<AnyViewHandle>) -> Self {
946 Self { view: view.into() }
947 }
948}
949
950impl Element for ChildView {
951 type LayoutState = ();
952 type PaintState = ();
953
954 fn layout(
955 &mut self,
956 constraint: SizeConstraint,
957 cx: &mut LayoutContext,
958 ) -> (Vector2F, Self::LayoutState) {
959 let size = cx.layout(self.view.id(), constraint);
960 (size, ())
961 }
962
963 fn paint(
964 &mut self,
965 bounds: RectF,
966 visible_bounds: RectF,
967 _: &mut Self::LayoutState,
968 cx: &mut PaintContext,
969 ) -> Self::PaintState {
970 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
971 }
972
973 fn dispatch_event(
974 &mut self,
975 event: &Event,
976 _: RectF,
977 _: RectF,
978 _: &mut Self::LayoutState,
979 _: &mut Self::PaintState,
980 cx: &mut EventContext,
981 ) -> bool {
982 cx.dispatch_event(self.view.id(), event)
983 }
984
985 fn rect_for_text_range(
986 &self,
987 range_utf16: Range<usize>,
988 _: RectF,
989 _: RectF,
990 _: &Self::LayoutState,
991 _: &Self::PaintState,
992 cx: &MeasurementContext,
993 ) -> Option<RectF> {
994 cx.rect_for_text_range(self.view.id(), range_utf16)
995 }
996
997 fn debug(
998 &self,
999 bounds: RectF,
1000 _: &Self::LayoutState,
1001 _: &Self::PaintState,
1002 cx: &DebugContext,
1003 ) -> serde_json::Value {
1004 json!({
1005 "type": "ChildView",
1006 "view_id": self.view.id(),
1007 "bounds": bounds.to_json(),
1008 "view": self.view.debug_json(cx.app),
1009 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
1010 view.debug(cx)
1011 } else {
1012 json!(null)
1013 }
1014 })
1015 }
1016}