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 invalidated_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 // Clicked status is used when rendering views via the RenderContext.
261 // So when it changes, these views need to be rerendered
262 for clicked_region_id in self.clicked_region_ids.iter() {
263 invalidated_views.insert(clicked_region_id.view_id());
264 }
265 self.clicked_button = Some(e.button);
266 }
267
268 events_to_send.push(MouseRegionEvent::Down(DownRegionEvent {
269 region: Default::default(),
270 platform_event: e.clone(),
271 }));
272 events_to_send.push(MouseRegionEvent::DownOut(DownOutRegionEvent {
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 UpRegionEvent events need to be pushed before
280 // ClickRegionEvents
281 events_to_send.push(MouseRegionEvent::Up(UpRegionEvent {
282 region: Default::default(),
283 platform_event: e.clone(),
284 }));
285 events_to_send.push(MouseRegionEvent::UpOut(UpOutRegionEvent {
286 region: Default::default(),
287 platform_event: e.clone(),
288 }));
289 events_to_send.push(MouseRegionEvent::Click(ClickRegionEvent {
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 events_to_send.push(MouseRegionEvent::Drag(DragRegionEvent {
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 events_to_send.push(MouseRegionEvent::Up(UpRegionEvent {
321 region: Default::default(),
322 platform_event: button_event.clone(),
323 }));
324 events_to_send.push(MouseRegionEvent::UpOut(UpOutRegionEvent {
325 region: Default::default(),
326 platform_event: button_event.clone(),
327 }));
328 events_to_send.push(MouseRegionEvent::Click(ClickRegionEvent {
329 region: Default::default(),
330 platform_event: button_event.clone(),
331 }));
332 }
333
334 events_to_send.push(MouseRegionEvent::Move(MoveRegionEvent {
335 region: Default::default(),
336 platform_event: e.clone(),
337 }));
338 }
339
340 events_to_send.push(MouseRegionEvent::Hover(HoverRegionEvent {
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) => {
349 events_to_send.push(MouseRegionEvent::ScrollWheel(ScrollWheelRegionEvent {
350 region: Default::default(),
351 platform_event: e.clone(),
352 }))
353 }
354
355 _ => {}
356 }
357
358 if let Some(position) = event.position() {
359 self.mouse_position = position;
360 }
361
362 let mut any_event_handled = false;
363 // 2. Process the raw mouse events into region events
364 for mut region_event in events_to_send {
365 let mut valid_regions = Vec::new();
366
367 // GPUI elements are arranged by depth but sibling elements can register overlapping
368 // mouse regions. As such, hover events are only fired on overlapping elements which
369 // are at the same depth as the topmost element which overlaps with the mouse.
370
371 match ®ion_event {
372 MouseRegionEvent::Hover(_) => {
373 let mut top_most_depth = None;
374 let mouse_position = self.mouse_position.clone();
375 for (region, depth) in self.mouse_regions.iter().rev() {
376 // Allow mouse regions to appear transparent to hovers
377 if !region.hoverable {
378 continue;
379 }
380
381 let contains_mouse = region.bounds.contains_point(mouse_position);
382
383 if contains_mouse && top_most_depth.is_none() {
384 top_most_depth = Some(depth);
385 }
386
387 // This unwrap relies on short circuiting boolean expressions
388 // The right side of the && is only executed when contains_mouse
389 // is true, and we know above that when contains_mouse is true
390 // top_most_depth is set
391 if contains_mouse && depth == top_most_depth.unwrap() {
392 //Ensure that hover entrance events aren't sent twice
393 if self.hovered_region_ids.insert(region.id()) {
394 valid_regions.push(region.clone());
395 invalidated_views.insert(region.id().view_id());
396 }
397 } else {
398 // Ensure that hover exit events aren't sent twice
399 if self.hovered_region_ids.remove(®ion.id()) {
400 valid_regions.push(region.clone());
401 invalidated_views.insert(region.id().view_id());
402 }
403 }
404 }
405 }
406 MouseRegionEvent::Click(e) => {
407 // Only raise click events if the released button is the same as the one stored
408 if self
409 .clicked_button
410 .map(|clicked_button| clicked_button == e.button)
411 .unwrap_or(false)
412 {
413 // Clear clicked regions and clicked button
414 let clicked_region_ids =
415 std::mem::replace(&mut self.clicked_region_ids, Default::default());
416 // Clicked status is used when rendering views via the RenderContext.
417 // So when it changes, these views need to be rerendered
418 for clicked_region_id in clicked_region_ids.iter() {
419 invalidated_views.insert(clicked_region_id.view_id());
420 }
421 self.clicked_button = None;
422
423 // Find regions which still overlap with the mouse since the last MouseDown happened
424 for (mouse_region, _) in self.mouse_regions.iter().rev() {
425 if clicked_region_ids.contains(&mouse_region.id()) {
426 if mouse_region.bounds.contains_point(self.mouse_position) {
427 valid_regions.push(mouse_region.clone());
428 }
429 }
430 }
431 }
432 }
433 MouseRegionEvent::Drag(_) => {
434 for (mouse_region, _) in self.mouse_regions.iter().rev() {
435 if self.clicked_region_ids.contains(&mouse_region.id()) {
436 valid_regions.push(mouse_region.clone());
437 }
438 }
439 }
440
441 MouseRegionEvent::UpOut(_) | MouseRegionEvent::DownOut(_) => {
442 for (mouse_region, _) in self.mouse_regions.iter().rev() {
443 // NOT contains
444 if !mouse_region.bounds.contains_point(self.mouse_position) {
445 valid_regions.push(mouse_region.clone());
446 }
447 }
448 }
449 _ => {
450 for (mouse_region, _) in self.mouse_regions.iter().rev() {
451 // Contains
452 if mouse_region.bounds.contains_point(self.mouse_position) {
453 valid_regions.push(mouse_region.clone());
454 }
455 }
456 }
457 }
458
459 //3. Fire region events
460 let hovered_region_ids = self.hovered_region_ids.clone();
461 for valid_region in valid_regions.into_iter() {
462 let mut event_cx = self.build_event_context(&mut invalidated_views, cx);
463
464 region_event.set_region(valid_region.bounds);
465 if let MouseRegionEvent::Hover(e) = &mut region_event {
466 e.started = hovered_region_ids.contains(&valid_region.id())
467 }
468 // Handle Down events if the MouseRegion has a Click or Drag handler. This makes the api more intuitive as you would
469 // not expect a MouseRegion to be transparent to Down events if it also has a Click handler.
470 // This behavior can be overridden by adding a Down handler that calls cx.propogate_event
471 if let MouseRegionEvent::Down(e) = ®ion_event {
472 if valid_region
473 .handlers
474 .contains_handler(MouseRegionEvent::click_disc(), Some(e.button))
475 || valid_region
476 .handlers
477 .contains_handler(MouseRegionEvent::drag_disc(), Some(e.button))
478 {
479 event_cx.handled = true;
480 }
481 }
482
483 if let Some(callback) = valid_region.handlers.get(®ion_event.handler_key()) {
484 event_cx.handled = true;
485 event_cx
486 .invalidated_views
487 .insert(valid_region.id().view_id());
488 event_cx.with_current_view(valid_region.id().view_id(), {
489 let region_event = region_event.clone();
490 |cx| {
491 callback(region_event, cx);
492 }
493 });
494 }
495
496 any_event_handled = any_event_handled || event_cx.handled;
497 // For bubbling events, if the event was handled, don't continue dispatching
498 // This only makes sense for local events.
499 if event_cx.handled && region_event.is_capturable() {
500 break;
501 }
502 }
503 }
504
505 if !any_event_handled && !event_reused {
506 let mut event_cx = self.build_event_context(&mut invalidated_views, cx);
507 any_event_handled = event_cx.dispatch_event(root_view_id, &event);
508 }
509
510 for view_id in invalidated_views {
511 cx.notify_view(self.window_id, view_id);
512 }
513
514 any_event_handled
515 } else {
516 false
517 }
518 }
519
520 pub fn build_event_context<'a>(
521 &'a mut self,
522 invalidated_views: &'a mut HashSet<usize>,
523 cx: &'a mut MutableAppContext,
524 ) -> EventContext<'a> {
525 EventContext {
526 rendered_views: &mut self.rendered_views,
527 font_cache: &self.font_cache,
528 text_layout_cache: &self.text_layout_cache,
529 view_stack: Default::default(),
530 invalidated_views,
531 notify_count: 0,
532 handled: false,
533 window_id: self.window_id,
534 app: cx,
535 }
536 }
537
538 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
539 let view = cx.root_view(self.window_id)?;
540 Some(json!({
541 "root_view": view.debug_json(cx),
542 "root_element": self.rendered_views.get(&view.id())
543 .map(|root_element| {
544 root_element.debug(&DebugContext {
545 rendered_views: &self.rendered_views,
546 font_cache: &self.font_cache,
547 app: cx,
548 })
549 })
550 }))
551 }
552}
553
554pub struct LayoutContext<'a> {
555 window_id: usize,
556 rendered_views: &'a mut HashMap<usize, ElementBox>,
557 view_stack: Vec<usize>,
558 pub font_cache: &'a Arc<FontCache>,
559 pub font_system: Arc<dyn FontSystem>,
560 pub text_layout_cache: &'a TextLayoutCache,
561 pub asset_cache: &'a AssetCache,
562 pub app: &'a mut MutableAppContext,
563 pub refreshing: bool,
564 pub window_size: Vector2F,
565 titlebar_height: f32,
566 appearance: Appearance,
567 hovered_region_ids: HashSet<MouseRegionId>,
568 clicked_region_ids: Option<(HashSet<MouseRegionId>, MouseButton)>,
569}
570
571impl<'a> LayoutContext<'a> {
572 pub(crate) fn keystrokes_for_action(
573 &self,
574 action: &dyn Action,
575 ) -> Option<SmallVec<[Keystroke; 2]>> {
576 self.app
577 .keystrokes_for_action(self.window_id, &self.view_stack, action)
578 }
579
580 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
581 let print_error = |view_id| {
582 format!(
583 "{} with id {}",
584 self.app.name_for_view(self.window_id, view_id).unwrap(),
585 view_id,
586 )
587 };
588 match (
589 self.view_stack.last(),
590 self.app.parents.get(&(self.window_id, view_id)),
591 ) {
592 (Some(layout_parent), Some(ParentId::View(app_parent))) => {
593 if layout_parent != app_parent {
594 panic!(
595 "View {} was laid out with parent {} when it was constructed with parent {}",
596 print_error(view_id),
597 print_error(*layout_parent),
598 print_error(*app_parent))
599 }
600 }
601 (None, Some(ParentId::View(app_parent))) => panic!(
602 "View {} was laid out without a parent when it was constructed with parent {}",
603 print_error(view_id),
604 print_error(*app_parent)
605 ),
606 (Some(layout_parent), Some(ParentId::Root)) => panic!(
607 "View {} was laid out with parent {} when it was constructed as a window root",
608 print_error(view_id),
609 print_error(*layout_parent),
610 ),
611 (_, None) => panic!(
612 "View {} did not have a registered parent in the app context",
613 print_error(view_id),
614 ),
615 _ => {}
616 }
617
618 self.view_stack.push(view_id);
619 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
620 let size = rendered_view.layout(constraint, self);
621 self.rendered_views.insert(view_id, rendered_view);
622 self.view_stack.pop();
623 size
624 }
625
626 pub fn render<F, V, T>(&mut self, handle: &ViewHandle<V>, f: F) -> T
627 where
628 F: FnOnce(&mut V, &mut RenderContext<V>) -> T,
629 V: View,
630 {
631 handle.update(self.app, |view, cx| {
632 let mut render_cx = RenderContext {
633 app: cx,
634 window_id: handle.window_id(),
635 view_id: handle.id(),
636 view_type: PhantomData,
637 titlebar_height: self.titlebar_height,
638 hovered_region_ids: self.hovered_region_ids.clone(),
639 clicked_region_ids: self.clicked_region_ids.clone(),
640 refreshing: self.refreshing,
641 appearance: self.appearance,
642 };
643 f(view, &mut render_cx)
644 })
645 }
646}
647
648impl<'a> Deref for LayoutContext<'a> {
649 type Target = MutableAppContext;
650
651 fn deref(&self) -> &Self::Target {
652 self.app
653 }
654}
655
656impl<'a> DerefMut for LayoutContext<'a> {
657 fn deref_mut(&mut self) -> &mut Self::Target {
658 self.app
659 }
660}
661
662impl<'a> ReadView for LayoutContext<'a> {
663 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
664 self.app.read_view(handle)
665 }
666}
667
668impl<'a> ReadModel for LayoutContext<'a> {
669 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
670 self.app.read_model(handle)
671 }
672}
673
674impl<'a> UpgradeModelHandle for LayoutContext<'a> {
675 fn upgrade_model_handle<T: Entity>(
676 &self,
677 handle: &WeakModelHandle<T>,
678 ) -> Option<ModelHandle<T>> {
679 self.app.upgrade_model_handle(handle)
680 }
681
682 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
683 self.app.model_handle_is_upgradable(handle)
684 }
685
686 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
687 self.app.upgrade_any_model_handle(handle)
688 }
689}
690
691impl<'a> UpgradeViewHandle for LayoutContext<'a> {
692 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
693 self.app.upgrade_view_handle(handle)
694 }
695
696 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
697 self.app.upgrade_any_view_handle(handle)
698 }
699}
700
701pub struct PaintContext<'a> {
702 rendered_views: &'a mut HashMap<usize, ElementBox>,
703 view_stack: Vec<usize>,
704 pub window_size: Vector2F,
705 pub scene: &'a mut Scene,
706 pub font_cache: &'a FontCache,
707 pub text_layout_cache: &'a TextLayoutCache,
708 pub app: &'a AppContext,
709}
710
711impl<'a> PaintContext<'a> {
712 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
713 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
714 self.view_stack.push(view_id);
715 tree.paint(origin, visible_bounds, self);
716 self.rendered_views.insert(view_id, tree);
717 self.view_stack.pop();
718 }
719 }
720
721 #[inline]
722 pub fn paint_layer<F>(&mut self, clip_bounds: Option<RectF>, f: F)
723 where
724 F: FnOnce(&mut Self),
725 {
726 self.scene.push_layer(clip_bounds);
727 f(self);
728 self.scene.pop_layer();
729 }
730
731 pub fn current_view_id(&self) -> usize {
732 *self.view_stack.last().unwrap()
733 }
734}
735
736impl<'a> Deref for PaintContext<'a> {
737 type Target = AppContext;
738
739 fn deref(&self) -> &Self::Target {
740 self.app
741 }
742}
743
744pub struct EventContext<'a> {
745 rendered_views: &'a mut HashMap<usize, ElementBox>,
746 pub font_cache: &'a FontCache,
747 pub text_layout_cache: &'a TextLayoutCache,
748 pub app: &'a mut MutableAppContext,
749 pub window_id: usize,
750 pub notify_count: usize,
751 view_stack: Vec<usize>,
752 handled: bool,
753 invalidated_views: &'a mut HashSet<usize>,
754}
755
756impl<'a> EventContext<'a> {
757 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
758 if let Some(mut element) = self.rendered_views.remove(&view_id) {
759 let result =
760 self.with_current_view(view_id, |this| element.dispatch_event(event, this));
761 self.rendered_views.insert(view_id, element);
762 result
763 } else {
764 false
765 }
766 }
767
768 fn with_current_view<F, T>(&mut self, view_id: usize, f: F) -> T
769 where
770 F: FnOnce(&mut Self) -> T,
771 {
772 self.view_stack.push(view_id);
773 let result = f(self);
774 self.view_stack.pop();
775 result
776 }
777
778 pub fn window_id(&self) -> usize {
779 self.window_id
780 }
781
782 pub fn view_id(&self) -> Option<usize> {
783 self.view_stack.last().copied()
784 }
785
786 pub fn is_parent_view_focused(&self) -> bool {
787 if let Some(parent_view_id) = self.view_stack.last() {
788 self.app.focused_view_id(self.window_id) == Some(*parent_view_id)
789 } else {
790 false
791 }
792 }
793
794 pub fn focus_parent_view(&mut self) {
795 if let Some(parent_view_id) = self.view_stack.last() {
796 self.app.focus(self.window_id, Some(*parent_view_id))
797 }
798 }
799
800 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
801 self.app
802 .dispatch_any_action_at(self.window_id, *self.view_stack.last().unwrap(), action)
803 }
804
805 pub fn dispatch_action<A: Action>(&mut self, action: A) {
806 self.dispatch_any_action(Box::new(action));
807 }
808
809 pub fn notify(&mut self) {
810 self.notify_count += 1;
811 if let Some(view_id) = self.view_stack.last() {
812 self.invalidated_views.insert(*view_id);
813 }
814 }
815
816 pub fn notify_count(&self) -> usize {
817 self.notify_count
818 }
819
820 pub fn propogate_event(&mut self) {
821 self.handled = false;
822 }
823}
824
825impl<'a> Deref for EventContext<'a> {
826 type Target = MutableAppContext;
827
828 fn deref(&self) -> &Self::Target {
829 self.app
830 }
831}
832
833impl<'a> DerefMut for EventContext<'a> {
834 fn deref_mut(&mut self) -> &mut Self::Target {
835 self.app
836 }
837}
838
839pub struct MeasurementContext<'a> {
840 app: &'a AppContext,
841 rendered_views: &'a HashMap<usize, ElementBox>,
842 pub window_id: usize,
843}
844
845impl<'a> Deref for MeasurementContext<'a> {
846 type Target = AppContext;
847
848 fn deref(&self) -> &Self::Target {
849 self.app
850 }
851}
852
853impl<'a> MeasurementContext<'a> {
854 fn rect_for_text_range(&self, view_id: usize, range_utf16: Range<usize>) -> Option<RectF> {
855 let element = self.rendered_views.get(&view_id)?;
856 element.rect_for_text_range(range_utf16, self)
857 }
858}
859
860pub struct DebugContext<'a> {
861 rendered_views: &'a HashMap<usize, ElementBox>,
862 pub font_cache: &'a FontCache,
863 pub app: &'a AppContext,
864}
865
866#[derive(Clone, Copy, Debug, Eq, PartialEq)]
867pub enum Axis {
868 Horizontal,
869 Vertical,
870}
871
872impl Axis {
873 pub fn invert(self) -> Self {
874 match self {
875 Self::Horizontal => Self::Vertical,
876 Self::Vertical => Self::Horizontal,
877 }
878 }
879}
880
881impl ToJson for Axis {
882 fn to_json(&self) -> serde_json::Value {
883 match self {
884 Axis::Horizontal => json!("horizontal"),
885 Axis::Vertical => json!("vertical"),
886 }
887 }
888}
889
890pub trait Vector2FExt {
891 fn along(self, axis: Axis) -> f32;
892}
893
894impl Vector2FExt for Vector2F {
895 fn along(self, axis: Axis) -> f32 {
896 match axis {
897 Axis::Horizontal => self.x(),
898 Axis::Vertical => self.y(),
899 }
900 }
901}
902
903#[derive(Copy, Clone, Debug)]
904pub struct SizeConstraint {
905 pub min: Vector2F,
906 pub max: Vector2F,
907}
908
909impl SizeConstraint {
910 pub fn new(min: Vector2F, max: Vector2F) -> Self {
911 Self { min, max }
912 }
913
914 pub fn strict(size: Vector2F) -> Self {
915 Self {
916 min: size,
917 max: size,
918 }
919 }
920
921 pub fn strict_along(axis: Axis, max: f32) -> Self {
922 match axis {
923 Axis::Horizontal => Self {
924 min: vec2f(max, 0.0),
925 max: vec2f(max, f32::INFINITY),
926 },
927 Axis::Vertical => Self {
928 min: vec2f(0.0, max),
929 max: vec2f(f32::INFINITY, max),
930 },
931 }
932 }
933
934 pub fn max_along(&self, axis: Axis) -> f32 {
935 match axis {
936 Axis::Horizontal => self.max.x(),
937 Axis::Vertical => self.max.y(),
938 }
939 }
940
941 pub fn min_along(&self, axis: Axis) -> f32 {
942 match axis {
943 Axis::Horizontal => self.min.x(),
944 Axis::Vertical => self.min.y(),
945 }
946 }
947
948 pub fn constrain(&self, size: Vector2F) -> Vector2F {
949 vec2f(
950 size.x().min(self.max.x()).max(self.min.x()),
951 size.y().min(self.max.y()).max(self.min.y()),
952 )
953 }
954}
955
956impl Default for SizeConstraint {
957 fn default() -> Self {
958 SizeConstraint {
959 min: Vector2F::zero(),
960 max: Vector2F::splat(f32::INFINITY),
961 }
962 }
963}
964
965impl ToJson for SizeConstraint {
966 fn to_json(&self) -> serde_json::Value {
967 json!({
968 "min": self.min.to_json(),
969 "max": self.max.to_json(),
970 })
971 }
972}
973
974pub struct ChildView {
975 view: AnyWeakViewHandle,
976 view_name: &'static str,
977}
978
979impl ChildView {
980 pub fn new(view: impl Into<AnyViewHandle>, cx: &AppContext) -> Self {
981 let view = view.into();
982 let view_name = cx.view_ui_name(view.window_id(), view.id()).unwrap();
983 Self {
984 view: view.downgrade(),
985 view_name,
986 }
987 }
988}
989
990impl Element for ChildView {
991 type LayoutState = bool;
992 type PaintState = ();
993
994 fn layout(
995 &mut self,
996 constraint: SizeConstraint,
997 cx: &mut LayoutContext,
998 ) -> (Vector2F, Self::LayoutState) {
999 if cx.rendered_views.contains_key(&self.view.id()) {
1000 let size = cx.layout(self.view.id(), constraint);
1001 (size, true)
1002 } else {
1003 log::error!(
1004 "layout called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1005 self.view.id(),
1006 self.view_name
1007 );
1008 (Vector2F::zero(), false)
1009 }
1010 }
1011
1012 fn paint(
1013 &mut self,
1014 bounds: RectF,
1015 visible_bounds: RectF,
1016 view_is_valid: &mut Self::LayoutState,
1017 cx: &mut PaintContext,
1018 ) {
1019 if *view_is_valid {
1020 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
1021 } else {
1022 log::error!(
1023 "paint called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1024 self.view.id(),
1025 self.view_name
1026 );
1027 }
1028 }
1029
1030 fn dispatch_event(
1031 &mut self,
1032 event: &Event,
1033 _: RectF,
1034 _: RectF,
1035 view_is_valid: &mut Self::LayoutState,
1036 _: &mut Self::PaintState,
1037 cx: &mut EventContext,
1038 ) -> bool {
1039 if *view_is_valid {
1040 cx.dispatch_event(self.view.id(), event)
1041 } else {
1042 log::error!(
1043 "dispatch_event called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1044 self.view.id(),
1045 self.view_name
1046 );
1047 false
1048 }
1049 }
1050
1051 fn rect_for_text_range(
1052 &self,
1053 range_utf16: Range<usize>,
1054 _: RectF,
1055 _: RectF,
1056 view_is_valid: &Self::LayoutState,
1057 _: &Self::PaintState,
1058 cx: &MeasurementContext,
1059 ) -> Option<RectF> {
1060 if *view_is_valid {
1061 cx.rect_for_text_range(self.view.id(), range_utf16)
1062 } else {
1063 log::error!(
1064 "rect_for_text_range called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1065 self.view.id(),
1066 self.view_name
1067 );
1068 None
1069 }
1070 }
1071
1072 fn debug(
1073 &self,
1074 bounds: RectF,
1075 _: &Self::LayoutState,
1076 _: &Self::PaintState,
1077 cx: &DebugContext,
1078 ) -> serde_json::Value {
1079 json!({
1080 "type": "ChildView",
1081 "view_id": self.view.id(),
1082 "bounds": bounds.to_json(),
1083 "view": if let Some(view) = self.view.upgrade(cx.app) {
1084 view.debug_json(cx.app)
1085 } else {
1086 json!(null)
1087 },
1088 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
1089 view.debug(cx)
1090 } else {
1091 json!(null)
1092 }
1093 })
1094 }
1095}