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 invalidation.updated.remove(view_id);
80 self.rendered_views.remove(view_id);
81 }
82 for view_id in &invalidation.updated {
83 self.rendered_views.insert(
84 *view_id,
85 cx.render_view(RenderParams {
86 window_id: self.window_id,
87 view_id: *view_id,
88 titlebar_height: self.titlebar_height,
89 hovered_region_ids: self.hovered_region_ids.clone(),
90 clicked_region_ids: self
91 .clicked_button
92 .map(|button| (self.clicked_region_ids.clone(), button)),
93 refreshing: false,
94 })
95 .unwrap(),
96 );
97 }
98 }
99
100 pub fn refresh(&mut self, invalidation: &mut WindowInvalidation, cx: &mut MutableAppContext) {
101 self.invalidate(invalidation, cx);
102 for (view_id, view) in &mut self.rendered_views {
103 if !invalidation.updated.contains(view_id) {
104 *view = cx
105 .render_view(RenderParams {
106 window_id: self.window_id,
107 view_id: *view_id,
108 titlebar_height: self.titlebar_height,
109 hovered_region_ids: self.hovered_region_ids.clone(),
110 clicked_region_ids: self
111 .clicked_button
112 .map(|button| (self.clicked_region_ids.clone(), button)),
113 refreshing: true,
114 })
115 .unwrap();
116 }
117 }
118 }
119
120 pub fn build_scene(
121 &mut self,
122 window_size: Vector2F,
123 scale_factor: f32,
124 refreshing: bool,
125 cx: &mut MutableAppContext,
126 ) -> Scene {
127 let mut scene = Scene::new(scale_factor);
128
129 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
130 self.layout(window_size, refreshing, cx);
131 let mut paint_cx = self.build_paint_context(&mut scene, window_size, cx);
132 paint_cx.paint(
133 root_view_id,
134 Vector2F::zero(),
135 RectF::new(Vector2F::zero(), window_size),
136 );
137 self.text_layout_cache.finish_frame();
138 self.cursor_regions = scene.cursor_regions();
139 self.mouse_regions = scene.mouse_regions();
140
141 if cx.window_is_active(self.window_id) {
142 if let Some(event) = self.last_mouse_moved_event.clone() {
143 self.dispatch_event(event, true, cx);
144 }
145 }
146 } else {
147 log::error!("could not find root_view_id for window {}", self.window_id);
148 }
149
150 scene
151 }
152
153 fn layout(&mut self, window_size: Vector2F, refreshing: bool, cx: &mut MutableAppContext) {
154 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
155 self.build_layout_context(window_size, refreshing, cx)
156 .layout(root_view_id, SizeConstraint::strict(window_size));
157 }
158 }
159
160 pub fn build_layout_context<'a>(
161 &'a mut self,
162 window_size: Vector2F,
163 refreshing: bool,
164 cx: &'a mut MutableAppContext,
165 ) -> LayoutContext<'a> {
166 LayoutContext {
167 window_id: self.window_id,
168 rendered_views: &mut self.rendered_views,
169 font_cache: &self.font_cache,
170 font_system: cx.platform().fonts(),
171 text_layout_cache: &self.text_layout_cache,
172 asset_cache: &self.asset_cache,
173 view_stack: Vec::new(),
174 refreshing,
175 hovered_region_ids: self.hovered_region_ids.clone(),
176 clicked_region_ids: self
177 .clicked_button
178 .map(|button| (self.clicked_region_ids.clone(), button)),
179 titlebar_height: self.titlebar_height,
180 window_size,
181 app: cx,
182 }
183 }
184
185 pub fn build_paint_context<'a>(
186 &'a mut self,
187 scene: &'a mut Scene,
188 window_size: Vector2F,
189 cx: &'a mut MutableAppContext,
190 ) -> PaintContext {
191 PaintContext {
192 scene,
193 window_size,
194 font_cache: &self.font_cache,
195 text_layout_cache: &self.text_layout_cache,
196 rendered_views: &mut self.rendered_views,
197 view_stack: Vec::new(),
198 app: cx,
199 }
200 }
201
202 pub fn rect_for_text_range(&self, range_utf16: Range<usize>, cx: &AppContext) -> Option<RectF> {
203 cx.focused_view_id(self.window_id).and_then(|view_id| {
204 let cx = MeasurementContext {
205 app: cx,
206 rendered_views: &self.rendered_views,
207 window_id: self.window_id,
208 };
209 cx.rect_for_text_range(view_id, range_utf16)
210 })
211 }
212
213 pub fn dispatch_event(
214 &mut self,
215 event: Event,
216 event_reused: bool,
217 cx: &mut MutableAppContext,
218 ) -> bool {
219 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
220 let mut events_to_send = Vec::new();
221 let mut invalidated_views: HashSet<usize> = Default::default();
222
223 // 1. Allocate the correct set of GPUI events generated from the platform events
224 // -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
225 // -> Also moves around mouse related state
226 match &event {
227 Event::MouseDown(e) => {
228 // Click events are weird because they can be fired after a drag event.
229 // MDN says that browsers handle this by starting from 'the most
230 // specific ancestor element that contained both [positions]'
231 // So we need to store the overlapping regions on mouse down.
232
233 // If there is already clicked_button stored, don't replace it.
234 if self.clicked_button.is_none() {
235 self.clicked_region_ids = self
236 .mouse_regions
237 .iter()
238 .filter_map(|(region, _)| {
239 if region.bounds.contains_point(e.position) {
240 Some(region.id())
241 } else {
242 None
243 }
244 })
245 .collect();
246
247 // Clicked status is used when rendering views via the RenderContext.
248 // So when it changes, these views need to be rerendered
249 for clicked_region_id in self.clicked_region_ids.iter() {
250 invalidated_views.insert(clicked_region_id.view_id());
251 }
252 self.clicked_button = Some(e.button);
253 }
254
255 events_to_send.push(MouseRegionEvent::Down(DownRegionEvent {
256 region: Default::default(),
257 platform_event: e.clone(),
258 }));
259 events_to_send.push(MouseRegionEvent::DownOut(DownOutRegionEvent {
260 region: Default::default(),
261 platform_event: e.clone(),
262 }));
263 }
264 Event::MouseUp(e) => {
265 // NOTE: The order of event pushes is important! MouseUp events MUST be fired
266 // before click events, and so the UpRegionEvent events need to be pushed before
267 // ClickRegionEvents
268 events_to_send.push(MouseRegionEvent::Up(UpRegionEvent {
269 region: Default::default(),
270 platform_event: e.clone(),
271 }));
272 events_to_send.push(MouseRegionEvent::UpOut(UpOutRegionEvent {
273 region: Default::default(),
274 platform_event: e.clone(),
275 }));
276 events_to_send.push(MouseRegionEvent::Click(ClickRegionEvent {
277 region: Default::default(),
278 platform_event: e.clone(),
279 }));
280 }
281 Event::MouseMoved(
282 e @ MouseMovedEvent {
283 position,
284 pressed_button,
285 ..
286 },
287 ) => {
288 let mut style_to_assign = CursorStyle::Arrow;
289 for region in self.cursor_regions.iter().rev() {
290 if region.bounds.contains_point(*position) {
291 style_to_assign = region.style;
292 break;
293 }
294 }
295 cx.platform().set_cursor_style(style_to_assign);
296
297 if !event_reused {
298 if pressed_button.is_some() {
299 events_to_send.push(MouseRegionEvent::Drag(DragRegionEvent {
300 region: Default::default(),
301 prev_mouse_position: self.mouse_position,
302 platform_event: e.clone(),
303 }));
304 } else if let Some(clicked_button) = self.clicked_button {
305 // Mouse up event happened outside the current window. Simulate mouse up button event
306 let button_event = e.to_button_event(clicked_button);
307 events_to_send.push(MouseRegionEvent::Up(UpRegionEvent {
308 region: Default::default(),
309 platform_event: button_event.clone(),
310 }));
311 events_to_send.push(MouseRegionEvent::UpOut(UpOutRegionEvent {
312 region: Default::default(),
313 platform_event: button_event.clone(),
314 }));
315 events_to_send.push(MouseRegionEvent::Click(ClickRegionEvent {
316 region: Default::default(),
317 platform_event: button_event.clone(),
318 }));
319 }
320
321 events_to_send.push(MouseRegionEvent::Move(MoveRegionEvent {
322 region: Default::default(),
323 platform_event: e.clone(),
324 }));
325 }
326
327 events_to_send.push(MouseRegionEvent::Hover(HoverRegionEvent {
328 region: Default::default(),
329 platform_event: e.clone(),
330 started: false,
331 }));
332
333 self.last_mouse_moved_event = Some(event.clone());
334 }
335 Event::ScrollWheel(e) => {
336 events_to_send.push(MouseRegionEvent::ScrollWheel(ScrollWheelRegionEvent {
337 region: Default::default(),
338 platform_event: e.clone(),
339 }))
340 }
341
342 _ => {}
343 }
344
345 if let Some(position) = event.position() {
346 self.mouse_position = position;
347 }
348
349 let mut any_event_handled = false;
350 // 2. Process the raw mouse events into region events
351 for mut region_event in events_to_send {
352 let mut valid_regions = Vec::new();
353
354 // GPUI elements are arranged by depth but sibling elements can register overlapping
355 // mouse regions. As such, hover events are only fired on overlapping elements which
356 // are at the same depth as the topmost element which overlaps with the mouse.
357
358 match ®ion_event {
359 MouseRegionEvent::Hover(_) => {
360 let mut top_most_depth = None;
361 let mouse_position = self.mouse_position.clone();
362 for (region, depth) in self.mouse_regions.iter().rev() {
363 // Allow mouse regions to appear transparent to hovers
364 if !region.hoverable {
365 continue;
366 }
367
368 let contains_mouse = region.bounds.contains_point(mouse_position);
369
370 if contains_mouse && top_most_depth.is_none() {
371 top_most_depth = Some(depth);
372 }
373
374 // This unwrap relies on short circuiting boolean expressions
375 // The right side of the && is only executed when contains_mouse
376 // is true, and we know above that when contains_mouse is true
377 // top_most_depth is set
378 if contains_mouse && depth == top_most_depth.unwrap() {
379 //Ensure that hover entrance events aren't sent twice
380 if self.hovered_region_ids.insert(region.id()) {
381 valid_regions.push(region.clone());
382 invalidated_views.insert(region.id().view_id());
383 }
384 } else {
385 // Ensure that hover exit events aren't sent twice
386 if self.hovered_region_ids.remove(®ion.id()) {
387 valid_regions.push(region.clone());
388 invalidated_views.insert(region.id().view_id());
389 }
390 }
391 }
392 }
393 MouseRegionEvent::Click(e) => {
394 // Only raise click events if the released button is the same as the one stored
395 if self
396 .clicked_button
397 .map(|clicked_button| clicked_button == e.button)
398 .unwrap_or(false)
399 {
400 // Clear clicked regions and clicked button
401 let clicked_region_ids =
402 std::mem::replace(&mut self.clicked_region_ids, Default::default());
403 // Clicked status is used when rendering views via the RenderContext.
404 // So when it changes, these views need to be rerendered
405 for clicked_region_id in clicked_region_ids.iter() {
406 invalidated_views.insert(clicked_region_id.view_id());
407 }
408 self.clicked_button = None;
409
410 // Find regions which still overlap with the mouse since the last MouseDown happened
411 for (mouse_region, _) in self.mouse_regions.iter().rev() {
412 if clicked_region_ids.contains(&mouse_region.id()) {
413 if mouse_region.bounds.contains_point(self.mouse_position) {
414 valid_regions.push(mouse_region.clone());
415 }
416 }
417 }
418 }
419 }
420 MouseRegionEvent::Drag(_) => {
421 for (mouse_region, _) in self.mouse_regions.iter().rev() {
422 if self.clicked_region_ids.contains(&mouse_region.id()) {
423 valid_regions.push(mouse_region.clone());
424 }
425 }
426 }
427
428 MouseRegionEvent::UpOut(_) | MouseRegionEvent::DownOut(_) => {
429 for (mouse_region, _) in self.mouse_regions.iter().rev() {
430 // NOT contains
431 if !mouse_region.bounds.contains_point(self.mouse_position) {
432 valid_regions.push(mouse_region.clone());
433 }
434 }
435 }
436 _ => {
437 for (mouse_region, _) in self.mouse_regions.iter().rev() {
438 // Contains
439 if mouse_region.bounds.contains_point(self.mouse_position) {
440 valid_regions.push(mouse_region.clone());
441 }
442 }
443 }
444 }
445
446 //3. Fire region events
447 let hovered_region_ids = self.hovered_region_ids.clone();
448 for valid_region in valid_regions.into_iter() {
449 let mut event_cx = self.build_event_context(&mut invalidated_views, cx);
450
451 region_event.set_region(valid_region.bounds);
452 if let MouseRegionEvent::Hover(e) = &mut region_event {
453 e.started = hovered_region_ids.contains(&valid_region.id())
454 }
455 // Handle Down events if the MouseRegion has a Click or Drag 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 || valid_region
463 .handlers
464 .contains_handler(MouseRegionEvent::drag_disc(), Some(e.button))
465 {
466 event_cx.handled = true;
467 }
468 }
469
470 if let Some(callback) = valid_region.handlers.get(®ion_event.handler_key()) {
471 event_cx.handled = true;
472 event_cx
473 .invalidated_views
474 .insert(valid_region.id().view_id());
475 event_cx.with_current_view(valid_region.id().view_id(), {
476 let region_event = region_event.clone();
477 |cx| {
478 callback(region_event, cx);
479 }
480 });
481 }
482
483 any_event_handled = any_event_handled || event_cx.handled;
484 // For bubbling events, if the event was handled, don't continue dispatching
485 // This only makes sense for local events.
486 if event_cx.handled && region_event.is_capturable() {
487 break;
488 }
489 }
490 }
491
492 if !any_event_handled && !event_reused {
493 let mut event_cx = self.build_event_context(&mut invalidated_views, cx);
494 any_event_handled = event_cx.dispatch_event(root_view_id, &event);
495 }
496
497 for view_id in invalidated_views {
498 cx.notify_view(self.window_id, view_id);
499 }
500
501 any_event_handled
502 } else {
503 false
504 }
505 }
506
507 pub fn build_event_context<'a>(
508 &'a mut self,
509 invalidated_views: &'a mut HashSet<usize>,
510 cx: &'a mut MutableAppContext,
511 ) -> EventContext<'a> {
512 EventContext {
513 rendered_views: &mut self.rendered_views,
514 font_cache: &self.font_cache,
515 text_layout_cache: &self.text_layout_cache,
516 view_stack: Default::default(),
517 invalidated_views,
518 notify_count: 0,
519 handled: false,
520 window_id: self.window_id,
521 app: cx,
522 }
523 }
524
525 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
526 let view = cx.root_view(self.window_id)?;
527 Some(json!({
528 "root_view": view.debug_json(cx),
529 "root_element": self.rendered_views.get(&view.id())
530 .map(|root_element| {
531 root_element.debug(&DebugContext {
532 rendered_views: &self.rendered_views,
533 font_cache: &self.font_cache,
534 app: cx,
535 })
536 })
537 }))
538 }
539}
540
541pub struct LayoutContext<'a> {
542 window_id: usize,
543 rendered_views: &'a mut HashMap<usize, ElementBox>,
544 view_stack: Vec<usize>,
545 pub font_cache: &'a Arc<FontCache>,
546 pub font_system: Arc<dyn FontSystem>,
547 pub text_layout_cache: &'a TextLayoutCache,
548 pub asset_cache: &'a AssetCache,
549 pub app: &'a mut MutableAppContext,
550 pub refreshing: bool,
551 pub window_size: Vector2F,
552 titlebar_height: f32,
553 hovered_region_ids: HashSet<MouseRegionId>,
554 clicked_region_ids: Option<(HashSet<MouseRegionId>, MouseButton)>,
555}
556
557impl<'a> LayoutContext<'a> {
558 pub(crate) fn keystrokes_for_action(
559 &self,
560 action: &dyn Action,
561 ) -> Option<SmallVec<[Keystroke; 2]>> {
562 self.app
563 .keystrokes_for_action(self.window_id, &self.view_stack, action)
564 }
565
566 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
567 let print_error = |view_id| {
568 format!(
569 "{} with id {}",
570 self.app.name_for_view(self.window_id, view_id).unwrap(),
571 view_id,
572 )
573 };
574 match (
575 self.view_stack.last(),
576 self.app.parents.get(&(self.window_id, view_id)),
577 ) {
578 (Some(layout_parent), Some(ParentId::View(app_parent))) => {
579 if layout_parent != app_parent {
580 panic!(
581 "View {} was laid out with parent {} when it was constructed with parent {}",
582 print_error(view_id),
583 print_error(*layout_parent),
584 print_error(*app_parent))
585 }
586 }
587 (None, Some(ParentId::View(app_parent))) => panic!(
588 "View {} was laid out without a parent when it was constructed with parent {}",
589 print_error(view_id),
590 print_error(*app_parent)
591 ),
592 (Some(layout_parent), Some(ParentId::Root)) => panic!(
593 "View {} was laid out with parent {} when it was constructed as a window root",
594 print_error(view_id),
595 print_error(*layout_parent),
596 ),
597 (_, None) => panic!(
598 "View {} did not have a registered parent in the app context",
599 print_error(view_id),
600 ),
601 _ => {}
602 }
603
604 self.view_stack.push(view_id);
605 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
606 let size = rendered_view.layout(constraint, self);
607 self.rendered_views.insert(view_id, rendered_view);
608 self.view_stack.pop();
609 size
610 }
611
612 pub fn render<F, V, T>(&mut self, handle: &ViewHandle<V>, f: F) -> T
613 where
614 F: FnOnce(&mut V, &mut RenderContext<V>) -> T,
615 V: View,
616 {
617 handle.update(self.app, |view, cx| {
618 let mut render_cx = RenderContext {
619 app: cx,
620 window_id: handle.window_id(),
621 view_id: handle.id(),
622 view_type: PhantomData,
623 titlebar_height: self.titlebar_height,
624 hovered_region_ids: self.hovered_region_ids.clone(),
625 clicked_region_ids: self.clicked_region_ids.clone(),
626 refreshing: self.refreshing,
627 };
628 f(view, &mut render_cx)
629 })
630 }
631}
632
633impl<'a> Deref for LayoutContext<'a> {
634 type Target = MutableAppContext;
635
636 fn deref(&self) -> &Self::Target {
637 self.app
638 }
639}
640
641impl<'a> DerefMut for LayoutContext<'a> {
642 fn deref_mut(&mut self) -> &mut Self::Target {
643 self.app
644 }
645}
646
647impl<'a> ReadView for LayoutContext<'a> {
648 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
649 self.app.read_view(handle)
650 }
651}
652
653impl<'a> ReadModel for LayoutContext<'a> {
654 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
655 self.app.read_model(handle)
656 }
657}
658
659impl<'a> UpgradeModelHandle for LayoutContext<'a> {
660 fn upgrade_model_handle<T: Entity>(
661 &self,
662 handle: &WeakModelHandle<T>,
663 ) -> Option<ModelHandle<T>> {
664 self.app.upgrade_model_handle(handle)
665 }
666
667 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
668 self.app.model_handle_is_upgradable(handle)
669 }
670
671 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
672 self.app.upgrade_any_model_handle(handle)
673 }
674}
675
676impl<'a> UpgradeViewHandle for LayoutContext<'a> {
677 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
678 self.app.upgrade_view_handle(handle)
679 }
680
681 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
682 self.app.upgrade_any_view_handle(handle)
683 }
684}
685
686pub struct PaintContext<'a> {
687 rendered_views: &'a mut HashMap<usize, ElementBox>,
688 view_stack: Vec<usize>,
689 pub window_size: Vector2F,
690 pub scene: &'a mut Scene,
691 pub font_cache: &'a FontCache,
692 pub text_layout_cache: &'a TextLayoutCache,
693 pub app: &'a AppContext,
694}
695
696impl<'a> PaintContext<'a> {
697 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
698 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
699 self.view_stack.push(view_id);
700 tree.paint(origin, visible_bounds, self);
701 self.rendered_views.insert(view_id, tree);
702 self.view_stack.pop();
703 }
704 }
705
706 #[inline]
707 pub fn paint_layer<F>(&mut self, clip_bounds: Option<RectF>, f: F)
708 where
709 F: FnOnce(&mut Self),
710 {
711 self.scene.push_layer(clip_bounds);
712 f(self);
713 self.scene.pop_layer();
714 }
715
716 pub fn current_view_id(&self) -> usize {
717 *self.view_stack.last().unwrap()
718 }
719}
720
721impl<'a> Deref for PaintContext<'a> {
722 type Target = AppContext;
723
724 fn deref(&self) -> &Self::Target {
725 self.app
726 }
727}
728
729pub struct EventContext<'a> {
730 rendered_views: &'a mut HashMap<usize, ElementBox>,
731 pub font_cache: &'a FontCache,
732 pub text_layout_cache: &'a TextLayoutCache,
733 pub app: &'a mut MutableAppContext,
734 pub window_id: usize,
735 pub notify_count: usize,
736 view_stack: Vec<usize>,
737 handled: bool,
738 invalidated_views: &'a mut HashSet<usize>,
739}
740
741impl<'a> EventContext<'a> {
742 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
743 if let Some(mut element) = self.rendered_views.remove(&view_id) {
744 let result =
745 self.with_current_view(view_id, |this| element.dispatch_event(event, this));
746 self.rendered_views.insert(view_id, element);
747 result
748 } else {
749 false
750 }
751 }
752
753 fn with_current_view<F, T>(&mut self, view_id: usize, f: F) -> T
754 where
755 F: FnOnce(&mut Self) -> T,
756 {
757 self.view_stack.push(view_id);
758 let result = f(self);
759 self.view_stack.pop();
760 result
761 }
762
763 pub fn window_id(&self) -> usize {
764 self.window_id
765 }
766
767 pub fn view_id(&self) -> Option<usize> {
768 self.view_stack.last().copied()
769 }
770
771 pub fn is_parent_view_focused(&self) -> bool {
772 if let Some(parent_view_id) = self.view_stack.last() {
773 self.app.focused_view_id(self.window_id) == Some(*parent_view_id)
774 } else {
775 false
776 }
777 }
778
779 pub fn focus_parent_view(&mut self) {
780 if let Some(parent_view_id) = self.view_stack.last() {
781 self.app.focus(self.window_id, Some(*parent_view_id))
782 }
783 }
784
785 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
786 self.app
787 .dispatch_any_action_at(self.window_id, *self.view_stack.last().unwrap(), action)
788 }
789
790 pub fn dispatch_action<A: Action>(&mut self, action: A) {
791 self.dispatch_any_action(Box::new(action));
792 }
793
794 pub fn notify(&mut self) {
795 self.notify_count += 1;
796 if let Some(view_id) = self.view_stack.last() {
797 self.invalidated_views.insert(*view_id);
798 }
799 }
800
801 pub fn notify_count(&self) -> usize {
802 self.notify_count
803 }
804
805 pub fn propogate_event(&mut self) {
806 self.handled = false;
807 }
808}
809
810impl<'a> Deref for EventContext<'a> {
811 type Target = MutableAppContext;
812
813 fn deref(&self) -> &Self::Target {
814 self.app
815 }
816}
817
818impl<'a> DerefMut for EventContext<'a> {
819 fn deref_mut(&mut self) -> &mut Self::Target {
820 self.app
821 }
822}
823
824pub struct MeasurementContext<'a> {
825 app: &'a AppContext,
826 rendered_views: &'a HashMap<usize, ElementBox>,
827 pub window_id: usize,
828}
829
830impl<'a> Deref for MeasurementContext<'a> {
831 type Target = AppContext;
832
833 fn deref(&self) -> &Self::Target {
834 self.app
835 }
836}
837
838impl<'a> MeasurementContext<'a> {
839 fn rect_for_text_range(&self, view_id: usize, range_utf16: Range<usize>) -> Option<RectF> {
840 let element = self.rendered_views.get(&view_id)?;
841 element.rect_for_text_range(range_utf16, self)
842 }
843}
844
845pub struct DebugContext<'a> {
846 rendered_views: &'a HashMap<usize, ElementBox>,
847 pub font_cache: &'a FontCache,
848 pub app: &'a AppContext,
849}
850
851#[derive(Clone, Copy, Debug, Eq, PartialEq)]
852pub enum Axis {
853 Horizontal,
854 Vertical,
855}
856
857impl Axis {
858 pub fn invert(self) -> Self {
859 match self {
860 Self::Horizontal => Self::Vertical,
861 Self::Vertical => Self::Horizontal,
862 }
863 }
864}
865
866impl ToJson for Axis {
867 fn to_json(&self) -> serde_json::Value {
868 match self {
869 Axis::Horizontal => json!("horizontal"),
870 Axis::Vertical => json!("vertical"),
871 }
872 }
873}
874
875pub trait Vector2FExt {
876 fn along(self, axis: Axis) -> f32;
877}
878
879impl Vector2FExt for Vector2F {
880 fn along(self, axis: Axis) -> f32 {
881 match axis {
882 Axis::Horizontal => self.x(),
883 Axis::Vertical => self.y(),
884 }
885 }
886}
887
888#[derive(Copy, Clone, Debug)]
889pub struct SizeConstraint {
890 pub min: Vector2F,
891 pub max: Vector2F,
892}
893
894impl SizeConstraint {
895 pub fn new(min: Vector2F, max: Vector2F) -> Self {
896 Self { min, max }
897 }
898
899 pub fn strict(size: Vector2F) -> Self {
900 Self {
901 min: size,
902 max: size,
903 }
904 }
905
906 pub fn strict_along(axis: Axis, max: f32) -> Self {
907 match axis {
908 Axis::Horizontal => Self {
909 min: vec2f(max, 0.0),
910 max: vec2f(max, f32::INFINITY),
911 },
912 Axis::Vertical => Self {
913 min: vec2f(0.0, max),
914 max: vec2f(f32::INFINITY, max),
915 },
916 }
917 }
918
919 pub fn max_along(&self, axis: Axis) -> f32 {
920 match axis {
921 Axis::Horizontal => self.max.x(),
922 Axis::Vertical => self.max.y(),
923 }
924 }
925
926 pub fn min_along(&self, axis: Axis) -> f32 {
927 match axis {
928 Axis::Horizontal => self.min.x(),
929 Axis::Vertical => self.min.y(),
930 }
931 }
932
933 pub fn constrain(&self, size: Vector2F) -> Vector2F {
934 vec2f(
935 size.x().min(self.max.x()).max(self.min.x()),
936 size.y().min(self.max.y()).max(self.min.y()),
937 )
938 }
939}
940
941impl Default for SizeConstraint {
942 fn default() -> Self {
943 SizeConstraint {
944 min: Vector2F::zero(),
945 max: Vector2F::splat(f32::INFINITY),
946 }
947 }
948}
949
950impl ToJson for SizeConstraint {
951 fn to_json(&self) -> serde_json::Value {
952 json!({
953 "min": self.min.to_json(),
954 "max": self.max.to_json(),
955 })
956 }
957}
958
959pub struct ChildView {
960 view: AnyViewHandle,
961}
962
963impl ChildView {
964 pub fn new(view: impl Into<AnyViewHandle>) -> Self {
965 Self { view: view.into() }
966 }
967}
968
969impl Element for ChildView {
970 type LayoutState = ();
971 type PaintState = ();
972
973 fn layout(
974 &mut self,
975 constraint: SizeConstraint,
976 cx: &mut LayoutContext,
977 ) -> (Vector2F, Self::LayoutState) {
978 let size = cx.layout(self.view.id(), constraint);
979 (size, ())
980 }
981
982 fn paint(
983 &mut self,
984 bounds: RectF,
985 visible_bounds: RectF,
986 _: &mut Self::LayoutState,
987 cx: &mut PaintContext,
988 ) -> Self::PaintState {
989 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
990 }
991
992 fn dispatch_event(
993 &mut self,
994 event: &Event,
995 _: RectF,
996 _: RectF,
997 _: &mut Self::LayoutState,
998 _: &mut Self::PaintState,
999 cx: &mut EventContext,
1000 ) -> bool {
1001 cx.dispatch_event(self.view.id(), event)
1002 }
1003
1004 fn rect_for_text_range(
1005 &self,
1006 range_utf16: Range<usize>,
1007 _: RectF,
1008 _: RectF,
1009 _: &Self::LayoutState,
1010 _: &Self::PaintState,
1011 cx: &MeasurementContext,
1012 ) -> Option<RectF> {
1013 cx.rect_for_text_range(self.view.id(), range_utf16)
1014 }
1015
1016 fn debug(
1017 &self,
1018 bounds: RectF,
1019 _: &Self::LayoutState,
1020 _: &Self::PaintState,
1021 cx: &DebugContext,
1022 ) -> serde_json::Value {
1023 json!({
1024 "type": "ChildView",
1025 "view_id": self.view.id(),
1026 "bounds": bounds.to_json(),
1027 "view": self.view.debug_json(cx.app),
1028 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
1029 view.debug(cx)
1030 } else {
1031 json!(null)
1032 }
1033 })
1034 }
1035}