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, AnyWeakViewHandle, Appearance,
16 AssetCache, ElementBox, Entity, FontSystem, ModelHandle, MouseButton, MouseMovedEvent,
17 MouseRegion, MouseRegionId, ParentId, ReadModel, ReadView, RenderContext, RenderParams, Scene,
18 UpgradeModelHandle, UpgradeViewHandle, 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 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 = Scene::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, 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 self.cursor_regions = scene.cursor_regions();
151 self.mouse_regions = scene.mouse_regions();
152
153 if cx.window_is_active(self.window_id) {
154 if let Some(event) = self.last_mouse_moved_event.clone() {
155 self.dispatch_event(event, true, cx);
156 }
157 }
158 } else {
159 log::error!("could not find root_view_id for window {}", self.window_id);
160 }
161
162 scene
163 }
164
165 fn layout(&mut self, window_size: Vector2F, refreshing: bool, cx: &mut MutableAppContext) {
166 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
167 self.build_layout_context(window_size, refreshing, cx)
168 .layout(root_view_id, SizeConstraint::strict(window_size));
169 }
170 }
171
172 pub fn build_layout_context<'a>(
173 &'a mut self,
174 window_size: Vector2F,
175 refreshing: bool,
176 cx: &'a mut MutableAppContext,
177 ) -> LayoutContext<'a> {
178 LayoutContext {
179 window_id: self.window_id,
180 rendered_views: &mut self.rendered_views,
181 font_cache: &self.font_cache,
182 font_system: cx.platform().fonts(),
183 text_layout_cache: &self.text_layout_cache,
184 asset_cache: &self.asset_cache,
185 view_stack: Vec::new(),
186 refreshing,
187 hovered_region_ids: self.hovered_region_ids.clone(),
188 clicked_region_ids: self
189 .clicked_button
190 .map(|button| (self.clicked_region_ids.clone(), button)),
191 titlebar_height: self.titlebar_height,
192 appearance: self.appearance,
193 window_size,
194 app: cx,
195 }
196 }
197
198 pub fn build_paint_context<'a>(
199 &'a mut self,
200 scene: &'a mut Scene,
201 window_size: Vector2F,
202 cx: &'a mut MutableAppContext,
203 ) -> PaintContext {
204 PaintContext {
205 scene,
206 window_size,
207 font_cache: &self.font_cache,
208 text_layout_cache: &self.text_layout_cache,
209 rendered_views: &mut self.rendered_views,
210 view_stack: Vec::new(),
211 app: cx,
212 }
213 }
214
215 pub fn rect_for_text_range(&self, range_utf16: Range<usize>, cx: &AppContext) -> Option<RectF> {
216 cx.focused_view_id(self.window_id).and_then(|view_id| {
217 let cx = MeasurementContext {
218 app: cx,
219 rendered_views: &self.rendered_views,
220 window_id: self.window_id,
221 };
222 cx.rect_for_text_range(view_id, range_utf16)
223 })
224 }
225
226 pub fn dispatch_event(
227 &mut self,
228 event: Event,
229 event_reused: bool,
230 cx: &mut MutableAppContext,
231 ) -> bool {
232 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
233 let mut events_to_send = Vec::new();
234 let mut notified_views: HashSet<usize> = Default::default();
235
236 // 1. Allocate the correct set of GPUI events generated from the platform events
237 // -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
238 // -> Also moves around mouse related state
239 match &event {
240 Event::MouseDown(e) => {
241 // Click events are weird because they can be fired after a drag event.
242 // MDN says that browsers handle this by starting from 'the most
243 // specific ancestor element that contained both [positions]'
244 // So we need to store the overlapping regions on mouse down.
245
246 // If there is already clicked_button stored, don't replace it.
247 if self.clicked_button.is_none() {
248 self.clicked_region_ids = self
249 .mouse_regions
250 .iter()
251 .filter_map(|(region, _)| {
252 if region.bounds.contains_point(e.position) {
253 Some(region.id())
254 } else {
255 None
256 }
257 })
258 .collect();
259
260 self.clicked_button = Some(e.button);
261 }
262
263 events_to_send.push(MouseRegionEvent::Down(DownRegionEvent {
264 region: Default::default(),
265 platform_event: e.clone(),
266 }));
267 events_to_send.push(MouseRegionEvent::DownOut(DownOutRegionEvent {
268 region: Default::default(),
269 platform_event: e.clone(),
270 }));
271 }
272 Event::MouseUp(e) => {
273 // NOTE: The order of event pushes is important! MouseUp events MUST be fired
274 // before click events, and so the UpRegionEvent events need to be pushed before
275 // ClickRegionEvents
276 events_to_send.push(MouseRegionEvent::Up(UpRegionEvent {
277 region: Default::default(),
278 platform_event: e.clone(),
279 }));
280 events_to_send.push(MouseRegionEvent::UpOut(UpOutRegionEvent {
281 region: Default::default(),
282 platform_event: e.clone(),
283 }));
284 events_to_send.push(MouseRegionEvent::Click(ClickRegionEvent {
285 region: Default::default(),
286 platform_event: e.clone(),
287 }));
288 }
289 Event::MouseMoved(
290 e @ MouseMovedEvent {
291 position,
292 pressed_button,
293 ..
294 },
295 ) => {
296 let mut style_to_assign = CursorStyle::Arrow;
297 for region in self.cursor_regions.iter().rev() {
298 if region.bounds.contains_point(*position) {
299 style_to_assign = region.style;
300 break;
301 }
302 }
303 cx.platform().set_cursor_style(style_to_assign);
304
305 if !event_reused {
306 if pressed_button.is_some() {
307 events_to_send.push(MouseRegionEvent::Drag(DragRegionEvent {
308 region: Default::default(),
309 prev_mouse_position: self.mouse_position,
310 platform_event: e.clone(),
311 }));
312 } else if let Some(clicked_button) = self.clicked_button {
313 // Mouse up event happened outside the current window. Simulate mouse up button event
314 let button_event = e.to_button_event(clicked_button);
315 events_to_send.push(MouseRegionEvent::Up(UpRegionEvent {
316 region: Default::default(),
317 platform_event: button_event.clone(),
318 }));
319 events_to_send.push(MouseRegionEvent::UpOut(UpOutRegionEvent {
320 region: Default::default(),
321 platform_event: button_event.clone(),
322 }));
323 events_to_send.push(MouseRegionEvent::Click(ClickRegionEvent {
324 region: Default::default(),
325 platform_event: button_event.clone(),
326 }));
327 }
328
329 events_to_send.push(MouseRegionEvent::Move(MoveRegionEvent {
330 region: Default::default(),
331 platform_event: e.clone(),
332 }));
333 }
334
335 events_to_send.push(MouseRegionEvent::Hover(HoverRegionEvent {
336 region: Default::default(),
337 platform_event: e.clone(),
338 started: false,
339 }));
340
341 self.last_mouse_moved_event = Some(event.clone());
342 }
343 Event::ScrollWheel(e) => {
344 events_to_send.push(MouseRegionEvent::ScrollWheel(ScrollWheelRegionEvent {
345 region: Default::default(),
346 platform_event: e.clone(),
347 }))
348 }
349
350 _ => {}
351 }
352
353 if let Some(position) = event.position() {
354 self.mouse_position = position;
355 }
356
357 let mut any_event_handled = false;
358 // 2. Process the raw mouse events into region events
359 for mut region_event in events_to_send {
360 let mut valid_regions = Vec::new();
361
362 // GPUI elements are arranged by depth but sibling elements can register overlapping
363 // mouse regions. As such, hover events are only fired on overlapping elements which
364 // are at the same depth as the topmost element which overlaps with the mouse.
365
366 match ®ion_event {
367 MouseRegionEvent::Hover(_) => {
368 let mut top_most_depth = None;
369 let mouse_position = self.mouse_position.clone();
370 for (region, depth) 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 && top_most_depth.is_none() {
379 top_most_depth = Some(depth);
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 // top_most_depth is set
386 if contains_mouse && depth == top_most_depth.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 MouseRegionEvent::Down(_) | MouseRegionEvent::Up(_) => {
406 for (region, _) in self.mouse_regions.iter().rev() {
407 if region.bounds.contains_point(self.mouse_position) {
408 if region.notify_on_click {
409 notified_views.insert(region.id().view_id());
410 }
411 valid_regions.push(region.clone());
412 }
413 }
414 }
415 MouseRegionEvent::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 MouseRegionEvent::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 MouseRegionEvent::UpOut(_) | MouseRegionEvent::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 region_event.set_region(valid_region.bounds);
469 if let MouseRegionEvent::Hover(e) = &mut region_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 MouseRegionEvent::Down(e) = ®ion_event {
476 if valid_region
477 .handlers
478 .contains_handler(MouseRegionEvent::click_disc(), Some(e.button))
479 || valid_region
480 .handlers
481 .contains_handler(MouseRegionEvent::drag_disc(), Some(e.button))
482 {
483 event_cx.handled = true;
484 }
485 }
486
487 if let Some(callback) = valid_region.handlers.get(®ion_event.handler_key()) {
488 event_cx.handled = true;
489 event_cx.with_current_view(valid_region.id().view_id(), {
490 let region_event = region_event.clone();
491 |cx| {
492 callback(region_event, cx);
493 }
494 });
495 }
496
497 any_event_handled = any_event_handled || event_cx.handled;
498 // For bubbling events, if the event was handled, don't continue dispatching
499 // This only makes sense for local events.
500 if event_cx.handled && region_event.is_capturable() {
501 break;
502 }
503 }
504 }
505
506 if !any_event_handled && !event_reused {
507 let mut event_cx = self.build_event_context(&mut notified_views, cx);
508 any_event_handled = event_cx.dispatch_event(root_view_id, &event);
509 }
510
511 for view_id in notified_views {
512 cx.notify_view(self.window_id, view_id);
513 }
514
515 any_event_handled
516 } else {
517 false
518 }
519 }
520
521 pub fn build_event_context<'a>(
522 &'a mut self,
523 notified_views: &'a mut HashSet<usize>,
524 cx: &'a mut MutableAppContext,
525 ) -> EventContext<'a> {
526 EventContext {
527 rendered_views: &mut self.rendered_views,
528 font_cache: &self.font_cache,
529 text_layout_cache: &self.text_layout_cache,
530 view_stack: Default::default(),
531 notified_views,
532 notify_count: 0,
533 handled: false,
534 window_id: self.window_id,
535 app: cx,
536 }
537 }
538
539 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
540 let view = cx.root_view(self.window_id)?;
541 Some(json!({
542 "root_view": view.debug_json(cx),
543 "root_element": self.rendered_views.get(&view.id())
544 .map(|root_element| {
545 root_element.debug(&DebugContext {
546 rendered_views: &self.rendered_views,
547 font_cache: &self.font_cache,
548 app: cx,
549 })
550 })
551 }))
552 }
553}
554
555pub struct LayoutContext<'a> {
556 window_id: usize,
557 rendered_views: &'a mut HashMap<usize, ElementBox>,
558 view_stack: Vec<usize>,
559 pub font_cache: &'a Arc<FontCache>,
560 pub font_system: Arc<dyn FontSystem>,
561 pub text_layout_cache: &'a TextLayoutCache,
562 pub asset_cache: &'a AssetCache,
563 pub app: &'a mut MutableAppContext,
564 pub refreshing: bool,
565 pub window_size: Vector2F,
566 titlebar_height: f32,
567 appearance: Appearance,
568 hovered_region_ids: HashSet<MouseRegionId>,
569 clicked_region_ids: Option<(HashSet<MouseRegionId>, MouseButton)>,
570}
571
572impl<'a> LayoutContext<'a> {
573 pub(crate) fn keystrokes_for_action(
574 &self,
575 action: &dyn Action,
576 ) -> Option<SmallVec<[Keystroke; 2]>> {
577 self.app
578 .keystrokes_for_action(self.window_id, &self.view_stack, action)
579 }
580
581 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
582 let print_error = |view_id| {
583 format!(
584 "{} with id {}",
585 self.app.name_for_view(self.window_id, view_id).unwrap(),
586 view_id,
587 )
588 };
589 match (
590 self.view_stack.last(),
591 self.app.parents.get(&(self.window_id, view_id)),
592 ) {
593 (Some(layout_parent), Some(ParentId::View(app_parent))) => {
594 if layout_parent != app_parent {
595 panic!(
596 "View {} was laid out with parent {} when it was constructed with parent {}",
597 print_error(view_id),
598 print_error(*layout_parent),
599 print_error(*app_parent))
600 }
601 }
602 (None, Some(ParentId::View(app_parent))) => panic!(
603 "View {} was laid out without a parent when it was constructed with parent {}",
604 print_error(view_id),
605 print_error(*app_parent)
606 ),
607 (Some(layout_parent), Some(ParentId::Root)) => panic!(
608 "View {} was laid out with parent {} when it was constructed as a window root",
609 print_error(view_id),
610 print_error(*layout_parent),
611 ),
612 (_, None) => panic!(
613 "View {} did not have a registered parent in the app context",
614 print_error(view_id),
615 ),
616 _ => {}
617 }
618
619 self.view_stack.push(view_id);
620 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
621 let size = rendered_view.layout(constraint, self);
622 self.rendered_views.insert(view_id, rendered_view);
623 self.view_stack.pop();
624 size
625 }
626
627 pub fn render<F, V, T>(&mut self, handle: &ViewHandle<V>, f: F) -> T
628 where
629 F: FnOnce(&mut V, &mut RenderContext<V>) -> T,
630 V: View,
631 {
632 handle.update(self.app, |view, cx| {
633 let mut render_cx = RenderContext {
634 app: cx,
635 window_id: handle.window_id(),
636 view_id: handle.id(),
637 view_type: PhantomData,
638 titlebar_height: self.titlebar_height,
639 hovered_region_ids: self.hovered_region_ids.clone(),
640 clicked_region_ids: self.clicked_region_ids.clone(),
641 refreshing: self.refreshing,
642 appearance: self.appearance,
643 };
644 f(view, &mut render_cx)
645 })
646 }
647}
648
649impl<'a> Deref for LayoutContext<'a> {
650 type Target = MutableAppContext;
651
652 fn deref(&self) -> &Self::Target {
653 self.app
654 }
655}
656
657impl<'a> DerefMut for LayoutContext<'a> {
658 fn deref_mut(&mut self) -> &mut Self::Target {
659 self.app
660 }
661}
662
663impl<'a> ReadView for LayoutContext<'a> {
664 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
665 self.app.read_view(handle)
666 }
667}
668
669impl<'a> ReadModel for LayoutContext<'a> {
670 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
671 self.app.read_model(handle)
672 }
673}
674
675impl<'a> UpgradeModelHandle for LayoutContext<'a> {
676 fn upgrade_model_handle<T: Entity>(
677 &self,
678 handle: &WeakModelHandle<T>,
679 ) -> Option<ModelHandle<T>> {
680 self.app.upgrade_model_handle(handle)
681 }
682
683 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
684 self.app.model_handle_is_upgradable(handle)
685 }
686
687 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
688 self.app.upgrade_any_model_handle(handle)
689 }
690}
691
692impl<'a> UpgradeViewHandle for LayoutContext<'a> {
693 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
694 self.app.upgrade_view_handle(handle)
695 }
696
697 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
698 self.app.upgrade_any_view_handle(handle)
699 }
700}
701
702pub struct PaintContext<'a> {
703 rendered_views: &'a mut HashMap<usize, ElementBox>,
704 view_stack: Vec<usize>,
705 pub window_size: Vector2F,
706 pub scene: &'a mut Scene,
707 pub font_cache: &'a FontCache,
708 pub text_layout_cache: &'a TextLayoutCache,
709 pub app: &'a AppContext,
710}
711
712impl<'a> PaintContext<'a> {
713 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
714 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
715 self.view_stack.push(view_id);
716 tree.paint(origin, visible_bounds, self);
717 self.rendered_views.insert(view_id, tree);
718 self.view_stack.pop();
719 }
720 }
721
722 #[inline]
723 pub fn paint_layer<F>(&mut self, clip_bounds: Option<RectF>, f: F)
724 where
725 F: FnOnce(&mut Self),
726 {
727 self.scene.push_layer(clip_bounds);
728 f(self);
729 self.scene.pop_layer();
730 }
731
732 pub fn current_view_id(&self) -> usize {
733 *self.view_stack.last().unwrap()
734 }
735}
736
737impl<'a> Deref for PaintContext<'a> {
738 type Target = AppContext;
739
740 fn deref(&self) -> &Self::Target {
741 self.app
742 }
743}
744
745pub struct EventContext<'a> {
746 rendered_views: &'a mut HashMap<usize, ElementBox>,
747 pub font_cache: &'a FontCache,
748 pub text_layout_cache: &'a TextLayoutCache,
749 pub app: &'a mut MutableAppContext,
750 pub window_id: usize,
751 pub notify_count: usize,
752 view_stack: Vec<usize>,
753 handled: bool,
754 notified_views: &'a mut HashSet<usize>,
755}
756
757impl<'a> EventContext<'a> {
758 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
759 if let Some(mut element) = self.rendered_views.remove(&view_id) {
760 let result =
761 self.with_current_view(view_id, |this| element.dispatch_event(event, this));
762 self.rendered_views.insert(view_id, element);
763 result
764 } else {
765 false
766 }
767 }
768
769 fn with_current_view<F, T>(&mut self, view_id: usize, f: F) -> T
770 where
771 F: FnOnce(&mut Self) -> T,
772 {
773 self.view_stack.push(view_id);
774 let result = f(self);
775 self.view_stack.pop();
776 result
777 }
778
779 pub fn window_id(&self) -> usize {
780 self.window_id
781 }
782
783 pub fn view_id(&self) -> Option<usize> {
784 self.view_stack.last().copied()
785 }
786
787 pub fn is_parent_view_focused(&self) -> bool {
788 if let Some(parent_view_id) = self.view_stack.last() {
789 self.app.focused_view_id(self.window_id) == Some(*parent_view_id)
790 } else {
791 false
792 }
793 }
794
795 pub fn focus_parent_view(&mut self) {
796 if let Some(parent_view_id) = self.view_stack.last() {
797 self.app.focus(self.window_id, Some(*parent_view_id))
798 }
799 }
800
801 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
802 self.app
803 .dispatch_any_action_at(self.window_id, *self.view_stack.last().unwrap(), action)
804 }
805
806 pub fn dispatch_action<A: Action>(&mut self, action: A) {
807 self.dispatch_any_action(Box::new(action));
808 }
809
810 pub fn notify(&mut self) {
811 self.notify_count += 1;
812 if let Some(view_id) = self.view_stack.last() {
813 self.notified_views.insert(*view_id);
814 }
815 }
816
817 pub fn notify_count(&self) -> usize {
818 self.notify_count
819 }
820
821 pub fn propogate_event(&mut self) {
822 self.handled = false;
823 }
824}
825
826impl<'a> Deref for EventContext<'a> {
827 type Target = MutableAppContext;
828
829 fn deref(&self) -> &Self::Target {
830 self.app
831 }
832}
833
834impl<'a> DerefMut for EventContext<'a> {
835 fn deref_mut(&mut self) -> &mut Self::Target {
836 self.app
837 }
838}
839
840pub struct MeasurementContext<'a> {
841 app: &'a AppContext,
842 rendered_views: &'a HashMap<usize, ElementBox>,
843 pub window_id: usize,
844}
845
846impl<'a> Deref for MeasurementContext<'a> {
847 type Target = AppContext;
848
849 fn deref(&self) -> &Self::Target {
850 self.app
851 }
852}
853
854impl<'a> MeasurementContext<'a> {
855 fn rect_for_text_range(&self, view_id: usize, range_utf16: Range<usize>) -> Option<RectF> {
856 let element = self.rendered_views.get(&view_id)?;
857 element.rect_for_text_range(range_utf16, self)
858 }
859}
860
861pub struct DebugContext<'a> {
862 rendered_views: &'a HashMap<usize, ElementBox>,
863 pub font_cache: &'a FontCache,
864 pub app: &'a AppContext,
865}
866
867#[derive(Clone, Copy, Debug, Eq, PartialEq)]
868pub enum Axis {
869 Horizontal,
870 Vertical,
871}
872
873impl Axis {
874 pub fn invert(self) -> Self {
875 match self {
876 Self::Horizontal => Self::Vertical,
877 Self::Vertical => Self::Horizontal,
878 }
879 }
880}
881
882impl ToJson for Axis {
883 fn to_json(&self) -> serde_json::Value {
884 match self {
885 Axis::Horizontal => json!("horizontal"),
886 Axis::Vertical => json!("vertical"),
887 }
888 }
889}
890
891pub trait Vector2FExt {
892 fn along(self, axis: Axis) -> f32;
893}
894
895impl Vector2FExt for Vector2F {
896 fn along(self, axis: Axis) -> f32 {
897 match axis {
898 Axis::Horizontal => self.x(),
899 Axis::Vertical => self.y(),
900 }
901 }
902}
903
904#[derive(Copy, Clone, Debug)]
905pub struct SizeConstraint {
906 pub min: Vector2F,
907 pub max: Vector2F,
908}
909
910impl SizeConstraint {
911 pub fn new(min: Vector2F, max: Vector2F) -> Self {
912 Self { min, max }
913 }
914
915 pub fn strict(size: Vector2F) -> Self {
916 Self {
917 min: size,
918 max: size,
919 }
920 }
921
922 pub fn strict_along(axis: Axis, max: f32) -> Self {
923 match axis {
924 Axis::Horizontal => Self {
925 min: vec2f(max, 0.0),
926 max: vec2f(max, f32::INFINITY),
927 },
928 Axis::Vertical => Self {
929 min: vec2f(0.0, max),
930 max: vec2f(f32::INFINITY, max),
931 },
932 }
933 }
934
935 pub fn max_along(&self, axis: Axis) -> f32 {
936 match axis {
937 Axis::Horizontal => self.max.x(),
938 Axis::Vertical => self.max.y(),
939 }
940 }
941
942 pub fn min_along(&self, axis: Axis) -> f32 {
943 match axis {
944 Axis::Horizontal => self.min.x(),
945 Axis::Vertical => self.min.y(),
946 }
947 }
948
949 pub fn constrain(&self, size: Vector2F) -> Vector2F {
950 vec2f(
951 size.x().min(self.max.x()).max(self.min.x()),
952 size.y().min(self.max.y()).max(self.min.y()),
953 )
954 }
955}
956
957impl Default for SizeConstraint {
958 fn default() -> Self {
959 SizeConstraint {
960 min: Vector2F::zero(),
961 max: Vector2F::splat(f32::INFINITY),
962 }
963 }
964}
965
966impl ToJson for SizeConstraint {
967 fn to_json(&self) -> serde_json::Value {
968 json!({
969 "min": self.min.to_json(),
970 "max": self.max.to_json(),
971 })
972 }
973}
974
975pub struct ChildView {
976 view: AnyWeakViewHandle,
977 view_name: &'static str,
978}
979
980impl ChildView {
981 pub fn new(view: impl Into<AnyViewHandle>, cx: &AppContext) -> Self {
982 let view = view.into();
983 let view_name = cx.view_ui_name(view.window_id(), view.id()).unwrap();
984 Self {
985 view: view.downgrade(),
986 view_name,
987 }
988 }
989}
990
991impl Element for ChildView {
992 type LayoutState = bool;
993 type PaintState = ();
994
995 fn layout(
996 &mut self,
997 constraint: SizeConstraint,
998 cx: &mut LayoutContext,
999 ) -> (Vector2F, Self::LayoutState) {
1000 if cx.rendered_views.contains_key(&self.view.id()) {
1001 let size = cx.layout(self.view.id(), constraint);
1002 (size, true)
1003 } else {
1004 log::error!(
1005 "layout called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1006 self.view.id(),
1007 self.view_name
1008 );
1009 (Vector2F::zero(), false)
1010 }
1011 }
1012
1013 fn paint(
1014 &mut self,
1015 bounds: RectF,
1016 visible_bounds: RectF,
1017 view_is_valid: &mut Self::LayoutState,
1018 cx: &mut PaintContext,
1019 ) {
1020 if *view_is_valid {
1021 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
1022 } else {
1023 log::error!(
1024 "paint called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1025 self.view.id(),
1026 self.view_name
1027 );
1028 }
1029 }
1030
1031 fn dispatch_event(
1032 &mut self,
1033 event: &Event,
1034 _: RectF,
1035 _: RectF,
1036 view_is_valid: &mut Self::LayoutState,
1037 _: &mut Self::PaintState,
1038 cx: &mut EventContext,
1039 ) -> bool {
1040 if *view_is_valid {
1041 cx.dispatch_event(self.view.id(), event)
1042 } else {
1043 log::error!(
1044 "dispatch_event called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1045 self.view.id(),
1046 self.view_name
1047 );
1048 false
1049 }
1050 }
1051
1052 fn rect_for_text_range(
1053 &self,
1054 range_utf16: Range<usize>,
1055 _: RectF,
1056 _: RectF,
1057 view_is_valid: &Self::LayoutState,
1058 _: &Self::PaintState,
1059 cx: &MeasurementContext,
1060 ) -> Option<RectF> {
1061 if *view_is_valid {
1062 cx.rect_for_text_range(self.view.id(), range_utf16)
1063 } else {
1064 log::error!(
1065 "rect_for_text_range called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1066 self.view.id(),
1067 self.view_name
1068 );
1069 None
1070 }
1071 }
1072
1073 fn debug(
1074 &self,
1075 bounds: RectF,
1076 _: &Self::LayoutState,
1077 _: &Self::PaintState,
1078 cx: &DebugContext,
1079 ) -> serde_json::Value {
1080 json!({
1081 "type": "ChildView",
1082 "view_id": self.view.id(),
1083 "bounds": bounds.to_json(),
1084 "view": if let Some(view) = self.view.upgrade(cx.app) {
1085 view.debug_json(cx.app)
1086 } else {
1087 json!(null)
1088 },
1089 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
1090 view.debug(cx)
1091 } else {
1092 json!(null)
1093 }
1094 })
1095 }
1096}