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 CursorRegion, MouseClick, MouseDown, MouseDownOut, MouseDrag, MouseEvent, MouseHover,
11 MouseMove, MouseScrollWheel, MouseUp, MouseUpOut, Scene,
12 },
13 text_layout::TextLayoutCache,
14 Action, AnyModelHandle, AnyViewHandle, AnyWeakModelHandle, AnyWeakViewHandle, Appearance,
15 AssetCache, ElementBox, Entity, FontSystem, ModelHandle, MouseButton, MouseMovedEvent,
16 MouseRegion, MouseRegionId, ParentId, ReadModel, ReadView, RenderContext, RenderParams,
17 SceneBuilder, UpgradeModelHandle, UpgradeViewHandle, View, ViewHandle, WeakModelHandle,
18 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 appearance: Appearance,
45}
46
47impl Presenter {
48 pub fn new(
49 window_id: usize,
50 titlebar_height: f32,
51 appearance: Appearance,
52 font_cache: Arc<FontCache>,
53 text_layout_cache: TextLayoutCache,
54 asset_cache: Arc<AssetCache>,
55 cx: &mut MutableAppContext,
56 ) -> Self {
57 Self {
58 window_id,
59 rendered_views: cx.render_views(window_id, titlebar_height, appearance),
60 cursor_regions: Default::default(),
61 mouse_regions: Default::default(),
62 font_cache,
63 text_layout_cache,
64 asset_cache,
65 last_mouse_moved_event: None,
66 hovered_region_ids: Default::default(),
67 clicked_region_ids: Default::default(),
68 clicked_button: None,
69 mouse_position: vec2f(0., 0.),
70 titlebar_height,
71 appearance,
72 }
73 }
74
75 pub fn invalidate(
76 &mut self,
77 invalidation: &mut WindowInvalidation,
78 appearance: Appearance,
79 cx: &mut MutableAppContext,
80 ) {
81 cx.start_frame();
82 self.appearance = appearance;
83 for view_id in &invalidation.removed {
84 invalidation.updated.remove(view_id);
85 self.rendered_views.remove(view_id);
86 }
87 for view_id in &invalidation.updated {
88 self.rendered_views.insert(
89 *view_id,
90 cx.render_view(RenderParams {
91 window_id: self.window_id,
92 view_id: *view_id,
93 titlebar_height: self.titlebar_height,
94 hovered_region_ids: self.hovered_region_ids.clone(),
95 clicked_region_ids: self
96 .clicked_button
97 .map(|button| (self.clicked_region_ids.clone(), button)),
98 refreshing: false,
99 appearance,
100 })
101 .unwrap(),
102 );
103 }
104 }
105
106 pub fn refresh(
107 &mut self,
108 invalidation: &mut WindowInvalidation,
109 appearance: Appearance,
110 cx: &mut MutableAppContext,
111 ) {
112 self.invalidate(invalidation, appearance, cx);
113 for (view_id, view) in &mut self.rendered_views {
114 if !invalidation.updated.contains(view_id) {
115 *view = cx
116 .render_view(RenderParams {
117 window_id: self.window_id,
118 view_id: *view_id,
119 titlebar_height: self.titlebar_height,
120 hovered_region_ids: self.hovered_region_ids.clone(),
121 clicked_region_ids: self
122 .clicked_button
123 .map(|button| (self.clicked_region_ids.clone(), button)),
124 refreshing: true,
125 appearance,
126 })
127 .unwrap();
128 }
129 }
130 }
131
132 pub fn build_scene(
133 &mut self,
134 window_size: Vector2F,
135 scale_factor: f32,
136 refreshing: bool,
137 cx: &mut MutableAppContext,
138 ) -> Scene {
139 let mut scene_builder = SceneBuilder::new(scale_factor);
140
141 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
142 self.layout(window_size, refreshing, cx);
143 let mut paint_cx = self.build_paint_context(&mut scene_builder, window_size, cx);
144 paint_cx.paint(
145 root_view_id,
146 Vector2F::zero(),
147 RectF::new(Vector2F::zero(), window_size),
148 );
149 self.text_layout_cache.finish_frame();
150 let scene = scene_builder.build();
151 self.cursor_regions = scene.cursor_regions();
152 self.mouse_regions = scene.mouse_regions();
153
154 if cx.window_is_active(self.window_id) {
155 if let Some(event) = self.last_mouse_moved_event.clone() {
156 self.dispatch_event(event, true, cx);
157 }
158 }
159
160 scene
161 } else {
162 log::error!("could not find root_view_id for window {}", self.window_id);
163 scene_builder.build()
164 }
165 }
166
167 fn layout(&mut self, window_size: Vector2F, refreshing: bool, cx: &mut MutableAppContext) {
168 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
169 self.build_layout_context(window_size, refreshing, cx)
170 .layout(root_view_id, SizeConstraint::strict(window_size));
171 }
172 }
173
174 pub fn build_layout_context<'a>(
175 &'a mut self,
176 window_size: Vector2F,
177 refreshing: bool,
178 cx: &'a mut MutableAppContext,
179 ) -> LayoutContext<'a> {
180 LayoutContext {
181 window_id: self.window_id,
182 rendered_views: &mut self.rendered_views,
183 font_cache: &self.font_cache,
184 font_system: cx.platform().fonts(),
185 text_layout_cache: &self.text_layout_cache,
186 asset_cache: &self.asset_cache,
187 view_stack: Vec::new(),
188 refreshing,
189 hovered_region_ids: self.hovered_region_ids.clone(),
190 clicked_region_ids: self
191 .clicked_button
192 .map(|button| (self.clicked_region_ids.clone(), button)),
193 titlebar_height: self.titlebar_height,
194 appearance: self.appearance,
195 window_size,
196 app: cx,
197 }
198 }
199
200 pub fn build_paint_context<'a>(
201 &'a mut self,
202 scene: &'a mut SceneBuilder,
203 window_size: Vector2F,
204 cx: &'a mut MutableAppContext,
205 ) -> PaintContext {
206 PaintContext {
207 scene,
208 window_size,
209 font_cache: &self.font_cache,
210 text_layout_cache: &self.text_layout_cache,
211 rendered_views: &mut self.rendered_views,
212 view_stack: Vec::new(),
213 app: cx,
214 }
215 }
216
217 pub fn rect_for_text_range(&self, range_utf16: Range<usize>, cx: &AppContext) -> Option<RectF> {
218 cx.focused_view_id(self.window_id).and_then(|view_id| {
219 let cx = MeasurementContext {
220 app: cx,
221 rendered_views: &self.rendered_views,
222 window_id: self.window_id,
223 };
224 cx.rect_for_text_range(view_id, range_utf16)
225 })
226 }
227
228 pub fn dispatch_event(
229 &mut self,
230 event: Event,
231 event_reused: bool,
232 cx: &mut MutableAppContext,
233 ) -> bool {
234 let mut mouse_events = SmallVec::<[_; 2]>::new();
235 let mut notified_views: HashSet<usize> = Default::default();
236
237 // 1. Handle platform event. Keyboard events get dispatched immediately, while mouse events
238 // get mapped into the mouse-specific MouseEvent type.
239 // -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
240 // -> Also updates mouse-related state
241 match &event {
242 Event::KeyDown(e) => return cx.dispatch_key_down(self.window_id, e),
243 Event::KeyUp(e) => return cx.dispatch_key_up(self.window_id, e),
244 Event::ModifiersChanged(e) => return cx.dispatch_modifiers_changed(self.window_id, e),
245 Event::MouseDown(e) => {
246 // Click events are weird because they can be fired after a drag event.
247 // MDN says that browsers handle this by starting from 'the most
248 // specific ancestor element that contained both [positions]'
249 // So we need to store the overlapping regions on mouse down.
250
251 // If there is already clicked_button stored, don't replace it.
252 if self.clicked_button.is_none() {
253 self.clicked_region_ids = self
254 .mouse_regions
255 .iter()
256 .filter_map(|(region, _)| {
257 if region.bounds.contains_point(e.position) {
258 Some(region.id())
259 } else {
260 None
261 }
262 })
263 .collect();
264
265 self.clicked_button = Some(e.button);
266 }
267
268 mouse_events.push(MouseEvent::Down(MouseDown {
269 region: Default::default(),
270 platform_event: e.clone(),
271 }));
272 mouse_events.push(MouseEvent::DownOut(MouseDownOut {
273 region: Default::default(),
274 platform_event: e.clone(),
275 }));
276 }
277 Event::MouseUp(e) => {
278 // NOTE: The order of event pushes is important! MouseUp events MUST be fired
279 // before click events, and so the MouseUp events need to be pushed before
280 // MouseClick events.
281 mouse_events.push(MouseEvent::Up(MouseUp {
282 region: Default::default(),
283 platform_event: e.clone(),
284 }));
285 mouse_events.push(MouseEvent::UpOut(MouseUpOut {
286 region: Default::default(),
287 platform_event: e.clone(),
288 }));
289 mouse_events.push(MouseEvent::Click(MouseClick {
290 region: Default::default(),
291 platform_event: e.clone(),
292 }));
293 }
294 Event::MouseMoved(
295 e @ MouseMovedEvent {
296 position,
297 pressed_button,
298 ..
299 },
300 ) => {
301 let mut style_to_assign = CursorStyle::Arrow;
302 for region in self.cursor_regions.iter().rev() {
303 if region.bounds.contains_point(*position) {
304 style_to_assign = region.style;
305 break;
306 }
307 }
308 cx.platform().set_cursor_style(style_to_assign);
309
310 if !event_reused {
311 if pressed_button.is_some() {
312 mouse_events.push(MouseEvent::Drag(MouseDrag {
313 region: Default::default(),
314 prev_mouse_position: self.mouse_position,
315 platform_event: e.clone(),
316 }));
317 } else if let Some(clicked_button) = self.clicked_button {
318 // Mouse up event happened outside the current window. Simulate mouse up button event
319 let button_event = e.to_button_event(clicked_button);
320 mouse_events.push(MouseEvent::Up(MouseUp {
321 region: Default::default(),
322 platform_event: button_event.clone(),
323 }));
324 mouse_events.push(MouseEvent::UpOut(MouseUpOut {
325 region: Default::default(),
326 platform_event: button_event.clone(),
327 }));
328 mouse_events.push(MouseEvent::Click(MouseClick {
329 region: Default::default(),
330 platform_event: button_event.clone(),
331 }));
332 }
333
334 mouse_events.push(MouseEvent::Move(MouseMove {
335 region: Default::default(),
336 platform_event: e.clone(),
337 }));
338 }
339
340 mouse_events.push(MouseEvent::Hover(MouseHover {
341 region: Default::default(),
342 platform_event: e.clone(),
343 started: false,
344 }));
345
346 self.last_mouse_moved_event = Some(event.clone());
347 }
348 Event::ScrollWheel(e) => mouse_events.push(MouseEvent::ScrollWheel(MouseScrollWheel {
349 region: Default::default(),
350 platform_event: e.clone(),
351 })),
352 }
353
354 if let Some(position) = event.position() {
355 self.mouse_position = position;
356 }
357
358 // 2. Dispatch mouse events on regions
359 let mut any_event_handled = false;
360 for mut mouse_event in mouse_events {
361 let mut valid_regions = Vec::new();
362
363 // GPUI elements are arranged by z_index but sibling elements can register overlapping
364 // mouse regions. As such, hover events are only fired on overlapping elements which
365 // are at the same z-index as the topmost element which overlaps with the mouse.
366 match &mouse_event {
367 MouseEvent::Hover(_) => {
368 let mut highest_z_index = None;
369 let mouse_position = self.mouse_position.clone();
370 for (region, z_index) in self.mouse_regions.iter().rev() {
371 // Allow mouse regions to appear transparent to hovers
372 if !region.hoverable {
373 continue;
374 }
375
376 let contains_mouse = region.bounds.contains_point(mouse_position);
377
378 if contains_mouse && highest_z_index.is_none() {
379 highest_z_index = Some(z_index);
380 }
381
382 // This unwrap relies on short circuiting boolean expressions
383 // The right side of the && is only executed when contains_mouse
384 // is true, and we know above that when contains_mouse is true
385 // highest_z_index is set.
386 if contains_mouse && z_index == highest_z_index.unwrap() {
387 //Ensure that hover entrance events aren't sent twice
388 if self.hovered_region_ids.insert(region.id()) {
389 valid_regions.push(region.clone());
390 if region.notify_on_hover {
391 notified_views.insert(region.id().view_id());
392 }
393 }
394 } else {
395 // Ensure that hover exit events aren't sent twice
396 if self.hovered_region_ids.remove(®ion.id()) {
397 valid_regions.push(region.clone());
398 if region.notify_on_hover {
399 notified_views.insert(region.id().view_id());
400 }
401 }
402 }
403 }
404 }
405 MouseEvent::Down(_) | MouseEvent::Up(_) => {
406 for (region, _) in self.mouse_regions.iter().rev() {
407 if region.bounds.contains_point(self.mouse_position) {
408 valid_regions.push(region.clone());
409 if region.notify_on_click {
410 notified_views.insert(region.id().view_id());
411 }
412 }
413 }
414 }
415 MouseEvent::Click(e) => {
416 // Only raise click events if the released button is the same as the one stored
417 if self
418 .clicked_button
419 .map(|clicked_button| clicked_button == e.button)
420 .unwrap_or(false)
421 {
422 // Clear clicked regions and clicked button
423 let clicked_region_ids =
424 std::mem::replace(&mut self.clicked_region_ids, Default::default());
425 self.clicked_button = None;
426
427 // Find regions which still overlap with the mouse since the last MouseDown happened
428 for (mouse_region, _) in self.mouse_regions.iter().rev() {
429 if clicked_region_ids.contains(&mouse_region.id()) {
430 if mouse_region.bounds.contains_point(self.mouse_position) {
431 valid_regions.push(mouse_region.clone());
432 }
433 }
434 }
435 }
436 }
437 MouseEvent::Drag(_) => {
438 for (mouse_region, _) in self.mouse_regions.iter().rev() {
439 if self.clicked_region_ids.contains(&mouse_region.id()) {
440 valid_regions.push(mouse_region.clone());
441 }
442 }
443 }
444
445 MouseEvent::UpOut(_) | MouseEvent::DownOut(_) => {
446 for (mouse_region, _) in self.mouse_regions.iter().rev() {
447 // NOT contains
448 if !mouse_region.bounds.contains_point(self.mouse_position) {
449 valid_regions.push(mouse_region.clone());
450 }
451 }
452 }
453 _ => {
454 for (mouse_region, _) in self.mouse_regions.iter().rev() {
455 // Contains
456 if mouse_region.bounds.contains_point(self.mouse_position) {
457 valid_regions.push(mouse_region.clone());
458 }
459 }
460 }
461 }
462
463 //3. Fire region events
464 let hovered_region_ids = self.hovered_region_ids.clone();
465 for valid_region in valid_regions.into_iter() {
466 let mut event_cx = self.build_event_context(&mut notified_views, cx);
467
468 mouse_event.set_region(valid_region.bounds);
469 if let MouseEvent::Hover(e) = &mut mouse_event {
470 e.started = hovered_region_ids.contains(&valid_region.id())
471 }
472 // Handle Down events if the MouseRegion has a Click or Drag handler. This makes the api more intuitive as you would
473 // not expect a MouseRegion to be transparent to Down events if it also has a Click handler.
474 // This behavior can be overridden by adding a Down handler that calls cx.propogate_event
475 if let MouseEvent::Down(e) = &mouse_event {
476 if valid_region
477 .handlers
478 .contains(MouseEvent::click_disc(), Some(e.button))
479 || valid_region
480 .handlers
481 .contains(MouseEvent::drag_disc(), Some(e.button))
482 {
483 event_cx.handled = true;
484 }
485 }
486
487 // `event_consumed` should only be true if there are any handlers for this event.
488 let mut event_consumed = false;
489 if let Some(callbacks) = valid_region.handlers.get(&mouse_event.handler_key()) {
490 event_consumed = true;
491 for callback in callbacks {
492 event_cx.handled = true;
493 event_cx.with_current_view(valid_region.id().view_id(), {
494 let region_event = mouse_event.clone();
495 |cx| callback(region_event, cx)
496 });
497 event_consumed &= event_cx.handled;
498 any_event_handled |= event_cx.handled;
499 }
500 }
501
502 // For bubbling events, if the event was handled, don't continue dispatching.
503 // This only makes sense for local events which return false from is_capturable.
504 if event_consumed && mouse_event.is_capturable() {
505 break;
506 }
507 }
508 }
509
510 for view_id in notified_views {
511 cx.notify_view(self.window_id, view_id);
512 }
513
514 any_event_handled
515 }
516
517 pub fn build_event_context<'a>(
518 &'a mut self,
519 notified_views: &'a mut HashSet<usize>,
520 cx: &'a mut MutableAppContext,
521 ) -> EventContext<'a> {
522 EventContext {
523 font_cache: &self.font_cache,
524 text_layout_cache: &self.text_layout_cache,
525 view_stack: Default::default(),
526 notified_views,
527 notify_count: 0,
528 handled: false,
529 window_id: self.window_id,
530 app: cx,
531 }
532 }
533
534 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
535 let view = cx.root_view(self.window_id)?;
536 Some(json!({
537 "root_view": view.debug_json(cx),
538 "root_element": self.rendered_views.get(&view.id())
539 .map(|root_element| {
540 root_element.debug(&DebugContext {
541 rendered_views: &self.rendered_views,
542 font_cache: &self.font_cache,
543 app: cx,
544 })
545 })
546 }))
547 }
548}
549
550pub struct LayoutContext<'a> {
551 window_id: usize,
552 rendered_views: &'a mut HashMap<usize, ElementBox>,
553 view_stack: Vec<usize>,
554 pub font_cache: &'a Arc<FontCache>,
555 pub font_system: Arc<dyn FontSystem>,
556 pub text_layout_cache: &'a TextLayoutCache,
557 pub asset_cache: &'a AssetCache,
558 pub app: &'a mut MutableAppContext,
559 pub refreshing: bool,
560 pub window_size: Vector2F,
561 titlebar_height: f32,
562 appearance: Appearance,
563 hovered_region_ids: HashSet<MouseRegionId>,
564 clicked_region_ids: Option<(HashSet<MouseRegionId>, MouseButton)>,
565}
566
567impl<'a> LayoutContext<'a> {
568 pub(crate) fn keystrokes_for_action(
569 &self,
570 action: &dyn Action,
571 ) -> Option<SmallVec<[Keystroke; 2]>> {
572 self.app
573 .keystrokes_for_action(self.window_id, &self.view_stack, action)
574 }
575
576 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
577 let print_error = |view_id| {
578 format!(
579 "{} with id {}",
580 self.app.name_for_view(self.window_id, view_id).unwrap(),
581 view_id,
582 )
583 };
584 match (
585 self.view_stack.last(),
586 self.app.parents.get(&(self.window_id, view_id)),
587 ) {
588 (Some(layout_parent), Some(ParentId::View(app_parent))) => {
589 if layout_parent != app_parent {
590 panic!(
591 "View {} was laid out with parent {} when it was constructed with parent {}",
592 print_error(view_id),
593 print_error(*layout_parent),
594 print_error(*app_parent))
595 }
596 }
597 (None, Some(ParentId::View(app_parent))) => panic!(
598 "View {} was laid out without a parent when it was constructed with parent {}",
599 print_error(view_id),
600 print_error(*app_parent)
601 ),
602 (Some(layout_parent), Some(ParentId::Root)) => panic!(
603 "View {} was laid out with parent {} when it was constructed as a window root",
604 print_error(view_id),
605 print_error(*layout_parent),
606 ),
607 (_, None) => panic!(
608 "View {} did not have a registered parent in the app context",
609 print_error(view_id),
610 ),
611 _ => {}
612 }
613
614 self.view_stack.push(view_id);
615 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
616 let size = rendered_view.layout(constraint, self);
617 self.rendered_views.insert(view_id, rendered_view);
618 self.view_stack.pop();
619 size
620 }
621
622 pub fn render<F, V, T>(&mut self, handle: &ViewHandle<V>, f: F) -> T
623 where
624 F: FnOnce(&mut V, &mut RenderContext<V>) -> T,
625 V: View,
626 {
627 handle.update(self.app, |view, cx| {
628 let mut render_cx = RenderContext {
629 app: cx,
630 window_id: handle.window_id(),
631 view_id: handle.id(),
632 view_type: PhantomData,
633 titlebar_height: self.titlebar_height,
634 hovered_region_ids: self.hovered_region_ids.clone(),
635 clicked_region_ids: self.clicked_region_ids.clone(),
636 refreshing: self.refreshing,
637 appearance: self.appearance,
638 };
639 f(view, &mut render_cx)
640 })
641 }
642}
643
644impl<'a> Deref for LayoutContext<'a> {
645 type Target = MutableAppContext;
646
647 fn deref(&self) -> &Self::Target {
648 self.app
649 }
650}
651
652impl<'a> DerefMut for LayoutContext<'a> {
653 fn deref_mut(&mut self) -> &mut Self::Target {
654 self.app
655 }
656}
657
658impl<'a> ReadView for LayoutContext<'a> {
659 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
660 self.app.read_view(handle)
661 }
662}
663
664impl<'a> ReadModel for LayoutContext<'a> {
665 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
666 self.app.read_model(handle)
667 }
668}
669
670impl<'a> UpgradeModelHandle for LayoutContext<'a> {
671 fn upgrade_model_handle<T: Entity>(
672 &self,
673 handle: &WeakModelHandle<T>,
674 ) -> Option<ModelHandle<T>> {
675 self.app.upgrade_model_handle(handle)
676 }
677
678 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
679 self.app.model_handle_is_upgradable(handle)
680 }
681
682 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
683 self.app.upgrade_any_model_handle(handle)
684 }
685}
686
687impl<'a> UpgradeViewHandle for LayoutContext<'a> {
688 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
689 self.app.upgrade_view_handle(handle)
690 }
691
692 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
693 self.app.upgrade_any_view_handle(handle)
694 }
695}
696
697pub struct PaintContext<'a> {
698 rendered_views: &'a mut HashMap<usize, ElementBox>,
699 view_stack: Vec<usize>,
700 pub window_size: Vector2F,
701 pub scene: &'a mut SceneBuilder,
702 pub font_cache: &'a FontCache,
703 pub text_layout_cache: &'a TextLayoutCache,
704 pub app: &'a AppContext,
705}
706
707impl<'a> PaintContext<'a> {
708 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
709 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
710 self.view_stack.push(view_id);
711 tree.paint(origin, visible_bounds, self);
712 self.rendered_views.insert(view_id, tree);
713 self.view_stack.pop();
714 }
715 }
716
717 #[inline]
718 pub fn paint_stacking_context<F>(
719 &mut self,
720 clip_bounds: Option<RectF>,
721 z_index: Option<usize>,
722 f: F,
723 ) where
724 F: FnOnce(&mut Self),
725 {
726 self.scene.push_stacking_context(clip_bounds, z_index);
727 f(self);
728 self.scene.pop_stacking_context();
729 }
730
731 #[inline]
732 pub fn paint_layer<F>(&mut self, clip_bounds: Option<RectF>, f: F)
733 where
734 F: FnOnce(&mut Self),
735 {
736 self.scene.push_layer(clip_bounds);
737 f(self);
738 self.scene.pop_layer();
739 }
740
741 pub fn current_view_id(&self) -> usize {
742 *self.view_stack.last().unwrap()
743 }
744}
745
746impl<'a> Deref for PaintContext<'a> {
747 type Target = AppContext;
748
749 fn deref(&self) -> &Self::Target {
750 self.app
751 }
752}
753
754pub struct EventContext<'a> {
755 pub font_cache: &'a FontCache,
756 pub text_layout_cache: &'a TextLayoutCache,
757 pub app: &'a mut MutableAppContext,
758 pub window_id: usize,
759 pub notify_count: usize,
760 view_stack: Vec<usize>,
761 handled: bool,
762 notified_views: &'a mut HashSet<usize>,
763}
764
765impl<'a> EventContext<'a> {
766 fn with_current_view<F, T>(&mut self, view_id: usize, f: F) -> T
767 where
768 F: FnOnce(&mut Self) -> T,
769 {
770 self.view_stack.push(view_id);
771 let result = f(self);
772 self.view_stack.pop();
773 result
774 }
775
776 pub fn window_id(&self) -> usize {
777 self.window_id
778 }
779
780 pub fn view_id(&self) -> Option<usize> {
781 self.view_stack.last().copied()
782 }
783
784 pub fn is_parent_view_focused(&self) -> bool {
785 if let Some(parent_view_id) = self.view_stack.last() {
786 self.app.focused_view_id(self.window_id) == Some(*parent_view_id)
787 } else {
788 false
789 }
790 }
791
792 pub fn focus_parent_view(&mut self) {
793 if let Some(parent_view_id) = self.view_stack.last() {
794 self.app.focus(self.window_id, Some(*parent_view_id))
795 }
796 }
797
798 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
799 self.app
800 .dispatch_any_action_at(self.window_id, *self.view_stack.last().unwrap(), action)
801 }
802
803 pub fn dispatch_action<A: Action>(&mut self, action: A) {
804 self.dispatch_any_action(Box::new(action));
805 }
806
807 pub fn notify(&mut self) {
808 self.notify_count += 1;
809 if let Some(view_id) = self.view_stack.last() {
810 self.notified_views.insert(*view_id);
811 }
812 }
813
814 pub fn notify_count(&self) -> usize {
815 self.notify_count
816 }
817
818 pub fn propagate_event(&mut self) {
819 self.handled = false;
820 }
821}
822
823impl<'a> Deref for EventContext<'a> {
824 type Target = MutableAppContext;
825
826 fn deref(&self) -> &Self::Target {
827 self.app
828 }
829}
830
831impl<'a> DerefMut for EventContext<'a> {
832 fn deref_mut(&mut self) -> &mut Self::Target {
833 self.app
834 }
835}
836
837pub struct MeasurementContext<'a> {
838 app: &'a AppContext,
839 rendered_views: &'a HashMap<usize, ElementBox>,
840 pub window_id: usize,
841}
842
843impl<'a> Deref for MeasurementContext<'a> {
844 type Target = AppContext;
845
846 fn deref(&self) -> &Self::Target {
847 self.app
848 }
849}
850
851impl<'a> MeasurementContext<'a> {
852 fn rect_for_text_range(&self, view_id: usize, range_utf16: Range<usize>) -> Option<RectF> {
853 let element = self.rendered_views.get(&view_id)?;
854 element.rect_for_text_range(range_utf16, self)
855 }
856}
857
858pub struct DebugContext<'a> {
859 rendered_views: &'a HashMap<usize, ElementBox>,
860 pub font_cache: &'a FontCache,
861 pub app: &'a AppContext,
862}
863
864#[derive(Clone, Copy, Debug, Eq, PartialEq)]
865pub enum Axis {
866 Horizontal,
867 Vertical,
868}
869
870impl Axis {
871 pub fn invert(self) -> Self {
872 match self {
873 Self::Horizontal => Self::Vertical,
874 Self::Vertical => Self::Horizontal,
875 }
876 }
877
878 pub fn component(&self, point: Vector2F) -> f32 {
879 match self {
880 Self::Horizontal => point.x(),
881 Self::Vertical => point.y(),
882 }
883 }
884}
885
886impl ToJson for Axis {
887 fn to_json(&self) -> serde_json::Value {
888 match self {
889 Axis::Horizontal => json!("horizontal"),
890 Axis::Vertical => json!("vertical"),
891 }
892 }
893}
894
895pub trait Vector2FExt {
896 fn along(self, axis: Axis) -> f32;
897}
898
899impl Vector2FExt for Vector2F {
900 fn along(self, axis: Axis) -> f32 {
901 match axis {
902 Axis::Horizontal => self.x(),
903 Axis::Vertical => self.y(),
904 }
905 }
906}
907
908#[derive(Copy, Clone, Debug)]
909pub struct SizeConstraint {
910 pub min: Vector2F,
911 pub max: Vector2F,
912}
913
914impl SizeConstraint {
915 pub fn new(min: Vector2F, max: Vector2F) -> Self {
916 Self { min, max }
917 }
918
919 pub fn strict(size: Vector2F) -> Self {
920 Self {
921 min: size,
922 max: size,
923 }
924 }
925
926 pub fn strict_along(axis: Axis, max: f32) -> Self {
927 match axis {
928 Axis::Horizontal => Self {
929 min: vec2f(max, 0.0),
930 max: vec2f(max, f32::INFINITY),
931 },
932 Axis::Vertical => Self {
933 min: vec2f(0.0, max),
934 max: vec2f(f32::INFINITY, max),
935 },
936 }
937 }
938
939 pub fn max_along(&self, axis: Axis) -> f32 {
940 match axis {
941 Axis::Horizontal => self.max.x(),
942 Axis::Vertical => self.max.y(),
943 }
944 }
945
946 pub fn min_along(&self, axis: Axis) -> f32 {
947 match axis {
948 Axis::Horizontal => self.min.x(),
949 Axis::Vertical => self.min.y(),
950 }
951 }
952
953 pub fn constrain(&self, size: Vector2F) -> Vector2F {
954 vec2f(
955 size.x().min(self.max.x()).max(self.min.x()),
956 size.y().min(self.max.y()).max(self.min.y()),
957 )
958 }
959}
960
961impl Default for SizeConstraint {
962 fn default() -> Self {
963 SizeConstraint {
964 min: Vector2F::zero(),
965 max: Vector2F::splat(f32::INFINITY),
966 }
967 }
968}
969
970impl ToJson for SizeConstraint {
971 fn to_json(&self) -> serde_json::Value {
972 json!({
973 "min": self.min.to_json(),
974 "max": self.max.to_json(),
975 })
976 }
977}
978
979pub struct ChildView {
980 view: AnyWeakViewHandle,
981 view_name: &'static str,
982}
983
984impl ChildView {
985 pub fn new(view: impl Into<AnyViewHandle>, cx: &AppContext) -> Self {
986 let view = view.into();
987 let view_name = cx.view_ui_name(view.window_id(), view.id()).unwrap();
988 Self {
989 view: view.downgrade(),
990 view_name,
991 }
992 }
993}
994
995impl Element for ChildView {
996 type LayoutState = bool;
997 type PaintState = ();
998
999 fn layout(
1000 &mut self,
1001 constraint: SizeConstraint,
1002 cx: &mut LayoutContext,
1003 ) -> (Vector2F, Self::LayoutState) {
1004 if cx.rendered_views.contains_key(&self.view.id()) {
1005 let size = cx.layout(self.view.id(), constraint);
1006 (size, true)
1007 } else {
1008 log::error!(
1009 "layout called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1010 self.view.id(),
1011 self.view_name
1012 );
1013 (Vector2F::zero(), false)
1014 }
1015 }
1016
1017 fn paint(
1018 &mut self,
1019 bounds: RectF,
1020 visible_bounds: RectF,
1021 view_is_valid: &mut Self::LayoutState,
1022 cx: &mut PaintContext,
1023 ) {
1024 if *view_is_valid {
1025 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
1026 } else {
1027 log::error!(
1028 "paint called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1029 self.view.id(),
1030 self.view_name
1031 );
1032 }
1033 }
1034
1035 fn rect_for_text_range(
1036 &self,
1037 range_utf16: Range<usize>,
1038 _: RectF,
1039 _: RectF,
1040 view_is_valid: &Self::LayoutState,
1041 _: &Self::PaintState,
1042 cx: &MeasurementContext,
1043 ) -> Option<RectF> {
1044 if *view_is_valid {
1045 cx.rect_for_text_range(self.view.id(), range_utf16)
1046 } else {
1047 log::error!(
1048 "rect_for_text_range called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1049 self.view.id(),
1050 self.view_name
1051 );
1052 None
1053 }
1054 }
1055
1056 fn debug(
1057 &self,
1058 bounds: RectF,
1059 _: &Self::LayoutState,
1060 _: &Self::PaintState,
1061 cx: &DebugContext,
1062 ) -> serde_json::Value {
1063 json!({
1064 "type": "ChildView",
1065 "view_id": self.view.id(),
1066 "bounds": bounds.to_json(),
1067 "view": if let Some(view) = self.view.upgrade(cx.app) {
1068 view.debug_json(cx.app)
1069 } else {
1070 json!(null)
1071 },
1072 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
1073 view.debug(cx)
1074 } else {
1075 json!(null)
1076 }
1077 })
1078 }
1079}