1use crate::{
2 app::{AppContext, MutableAppContext, WindowInvalidation},
3 elements::Element,
4 font_cache::FontCache,
5 geometry::rect::RectF,
6 json::{self, ToJson},
7 platform::{CursorStyle, Event},
8 scene::CursorRegion,
9 text_layout::TextLayoutCache,
10 Action, AnyModelHandle, AnyViewHandle, AnyWeakModelHandle, AssetCache, ElementBox, Entity,
11 FontSystem, ModelHandle, MouseRegion, MouseRegionId, ReadModel, ReadView, RenderContext,
12 RenderParams, Scene, UpgradeModelHandle, UpgradeViewHandle, View, ViewHandle, WeakModelHandle,
13 WeakViewHandle,
14};
15use pathfinder_geometry::vector::{vec2f, Vector2F};
16use serde_json::json;
17use std::{
18 collections::{HashMap, HashSet},
19 marker::PhantomData,
20 ops::{Deref, DerefMut},
21 sync::Arc,
22};
23
24pub struct Presenter {
25 window_id: usize,
26 pub(crate) rendered_views: HashMap<usize, ElementBox>,
27 parents: HashMap<usize, usize>,
28 cursor_regions: Vec<CursorRegion>,
29 mouse_regions: Vec<MouseRegion>,
30 font_cache: Arc<FontCache>,
31 text_layout_cache: TextLayoutCache,
32 asset_cache: Arc<AssetCache>,
33 last_mouse_moved_event: Option<Event>,
34 hovered_region_ids: HashSet<MouseRegionId>,
35 clicked_region: Option<MouseRegion>,
36 prev_drag_position: Option<Vector2F>,
37 titlebar_height: f32,
38}
39
40impl Presenter {
41 pub fn new(
42 window_id: usize,
43 titlebar_height: f32,
44 font_cache: Arc<FontCache>,
45 text_layout_cache: TextLayoutCache,
46 asset_cache: Arc<AssetCache>,
47 cx: &mut MutableAppContext,
48 ) -> Self {
49 Self {
50 window_id,
51 rendered_views: cx.render_views(window_id, titlebar_height),
52 parents: HashMap::new(),
53 cursor_regions: Default::default(),
54 mouse_regions: Default::default(),
55 font_cache,
56 text_layout_cache,
57 asset_cache,
58 last_mouse_moved_event: None,
59 hovered_region_ids: Default::default(),
60 clicked_region: None,
61 prev_drag_position: None,
62 titlebar_height,
63 }
64 }
65
66 pub fn dispatch_path(&self, app: &AppContext) -> Vec<usize> {
67 let mut path = Vec::new();
68 if let Some(view_id) = app.focused_view_id(self.window_id) {
69 self.compute_dispatch_path_from(view_id, &mut path)
70 }
71 path
72 }
73
74 pub(crate) fn compute_dispatch_path_from(&self, mut view_id: usize, path: &mut Vec<usize>) {
75 path.push(view_id);
76 while let Some(parent_id) = self.parents.get(&view_id).copied() {
77 path.push(parent_id);
78 view_id = parent_id;
79 }
80 path.reverse();
81 }
82
83 pub fn invalidate(
84 &mut self,
85 invalidation: &mut WindowInvalidation,
86 cx: &mut MutableAppContext,
87 ) {
88 cx.start_frame();
89 for view_id in &invalidation.removed {
90 invalidation.updated.remove(&view_id);
91 self.rendered_views.remove(&view_id);
92 self.parents.remove(&view_id);
93 }
94 for view_id in &invalidation.updated {
95 self.rendered_views.insert(
96 *view_id,
97 cx.render_view(RenderParams {
98 window_id: self.window_id,
99 view_id: *view_id,
100 titlebar_height: self.titlebar_height,
101 hovered_region_ids: self.hovered_region_ids.clone(),
102 clicked_region_id: self.clicked_region.as_ref().map(MouseRegion::id),
103 refreshing: false,
104 })
105 .unwrap(),
106 );
107 }
108 }
109
110 pub fn refresh(&mut self, invalidation: &mut WindowInvalidation, cx: &mut MutableAppContext) {
111 self.invalidate(invalidation, cx);
112 for (view_id, view) in &mut self.rendered_views {
113 if !invalidation.updated.contains(view_id) {
114 *view = cx
115 .render_view(RenderParams {
116 window_id: self.window_id,
117 view_id: *view_id,
118 titlebar_height: self.titlebar_height,
119 hovered_region_ids: self.hovered_region_ids.clone(),
120 clicked_region_id: self.clicked_region.as_ref().map(MouseRegion::id),
121 refreshing: true,
122 })
123 .unwrap();
124 }
125 }
126 }
127
128 pub fn build_scene(
129 &mut self,
130 window_size: Vector2F,
131 scale_factor: f32,
132 refreshing: bool,
133 cx: &mut MutableAppContext,
134 ) -> Scene {
135 let mut scene = Scene::new(scale_factor);
136
137 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
138 self.layout(window_size, refreshing, cx);
139 let mut paint_cx = self.build_paint_context(&mut scene, cx);
140 paint_cx.paint(
141 root_view_id,
142 Vector2F::zero(),
143 RectF::new(Vector2F::zero(), window_size),
144 );
145 self.text_layout_cache.finish_frame();
146 self.cursor_regions = scene.cursor_regions();
147 self.mouse_regions = scene.mouse_regions();
148
149 if cx.window_is_active(self.window_id) {
150 if let Some(event) = self.last_mouse_moved_event.clone() {
151 self.dispatch_event(event, cx)
152 }
153 }
154 } else {
155 log::error!("could not find root_view_id for window {}", self.window_id);
156 }
157
158 scene
159 }
160
161 fn layout(&mut self, size: Vector2F, refreshing: bool, cx: &mut MutableAppContext) {
162 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
163 self.build_layout_context(refreshing, cx)
164 .layout(root_view_id, SizeConstraint::strict(size));
165 }
166 }
167
168 pub fn build_layout_context<'a>(
169 &'a mut self,
170 refreshing: bool,
171 cx: &'a mut MutableAppContext,
172 ) -> LayoutContext<'a> {
173 LayoutContext {
174 rendered_views: &mut self.rendered_views,
175 parents: &mut self.parents,
176 font_cache: &self.font_cache,
177 font_system: cx.platform().fonts(),
178 text_layout_cache: &self.text_layout_cache,
179 asset_cache: &self.asset_cache,
180 view_stack: Vec::new(),
181 refreshing,
182 hovered_region_ids: self.hovered_region_ids.clone(),
183 clicked_region_id: self.clicked_region.as_ref().map(MouseRegion::id),
184 titlebar_height: self.titlebar_height,
185 app: cx,
186 }
187 }
188
189 pub fn build_paint_context<'a>(
190 &'a mut self,
191 scene: &'a mut Scene,
192 cx: &'a mut MutableAppContext,
193 ) -> PaintContext {
194 PaintContext {
195 scene,
196 font_cache: &self.font_cache,
197 text_layout_cache: &self.text_layout_cache,
198 rendered_views: &mut self.rendered_views,
199 view_stack: Vec::new(),
200 app: cx,
201 }
202 }
203
204 pub fn dispatch_event(&mut self, event: Event, cx: &mut MutableAppContext) {
205 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
206 let mut invalidated_views = Vec::new();
207 let mut hovered_regions = Vec::new();
208 let mut unhovered_regions = Vec::new();
209 let mut clicked_region = None;
210 let mut dragged_region = None;
211
212 match event {
213 Event::LeftMouseDown { position, .. } => {
214 for region in self.mouse_regions.iter().rev() {
215 if region.bounds.contains_point(position) {
216 invalidated_views.push(region.view_id);
217 self.clicked_region = Some(region.clone());
218 self.prev_drag_position = Some(position);
219 break;
220 }
221 }
222 }
223 Event::LeftMouseUp {
224 position,
225 click_count,
226 ..
227 } => {
228 self.prev_drag_position.take();
229 if let Some(region) = self.clicked_region.take() {
230 invalidated_views.push(region.view_id);
231 if region.bounds.contains_point(position) {
232 clicked_region = Some((region, position, click_count));
233 }
234 }
235 }
236 Event::MouseMoved {
237 position,
238 left_mouse_down,
239 } => {
240 self.last_mouse_moved_event = Some(event.clone());
241
242 if !left_mouse_down {
243 let mut style_to_assign = CursorStyle::Arrow;
244 for region in self.cursor_regions.iter().rev() {
245 if region.bounds.contains_point(position) {
246 style_to_assign = region.style;
247 break;
248 }
249 }
250 cx.platform().set_cursor_style(style_to_assign);
251
252 for region in self.mouse_regions.iter().rev() {
253 let region_id = region.id();
254 if region.bounds.contains_point(position) {
255 if !self.hovered_region_ids.contains(®ion_id) {
256 invalidated_views.push(region.view_id);
257 hovered_regions.push(region.clone());
258 self.hovered_region_ids.insert(region_id);
259 }
260 } else {
261 if self.hovered_region_ids.contains(®ion_id) {
262 invalidated_views.push(region.view_id);
263 unhovered_regions.push(region.clone());
264 self.hovered_region_ids.remove(®ion_id);
265 }
266 }
267 }
268 }
269 }
270 Event::LeftMouseDragged { position } => {
271 if let Some((clicked_region, prev_drag_position)) = self
272 .clicked_region
273 .as_ref()
274 .zip(self.prev_drag_position.as_mut())
275 {
276 dragged_region =
277 Some((clicked_region.clone(), position - *prev_drag_position));
278 *prev_drag_position = position;
279 }
280
281 self.last_mouse_moved_event = Some(Event::MouseMoved {
282 position,
283 left_mouse_down: true,
284 });
285 }
286 _ => {}
287 }
288
289 let mut event_cx = self.build_event_context(cx);
290 for unhovered_region in unhovered_regions {
291 if let Some(hover_callback) = unhovered_region.hover {
292 event_cx.with_current_view(unhovered_region.view_id, |event_cx| {
293 hover_callback(false, event_cx);
294 })
295 }
296 }
297
298 for hovered_region in hovered_regions {
299 if let Some(hover_callback) = hovered_region.hover {
300 event_cx.with_current_view(hovered_region.view_id, |event_cx| {
301 hover_callback(true, event_cx);
302 })
303 }
304 }
305
306 if let Some((clicked_region, position, click_count)) = clicked_region {
307 if let Some(click_callback) = clicked_region.click {
308 event_cx.with_current_view(clicked_region.view_id, |event_cx| {
309 click_callback(position, click_count, event_cx);
310 })
311 }
312 }
313
314 if let Some((dragged_region, delta)) = dragged_region {
315 if let Some(drag_callback) = dragged_region.drag {
316 event_cx.with_current_view(dragged_region.view_id, |event_cx| {
317 drag_callback(delta, event_cx);
318 })
319 }
320 }
321
322 event_cx.dispatch_event(root_view_id, &event);
323
324 invalidated_views.extend(event_cx.invalidated_views);
325 let dispatch_directives = event_cx.dispatched_actions;
326
327 for view_id in invalidated_views {
328 cx.notify_view(self.window_id, view_id);
329 }
330
331 let mut dispatch_path = Vec::new();
332 for directive in dispatch_directives {
333 dispatch_path.clear();
334 if let Some(view_id) = directive.dispatcher_view_id {
335 self.compute_dispatch_path_from(view_id, &mut dispatch_path);
336 }
337 cx.dispatch_action_any(self.window_id, &dispatch_path, directive.action.as_ref());
338 }
339 }
340 }
341
342 pub fn build_event_context<'a>(
343 &'a mut self,
344 cx: &'a mut MutableAppContext,
345 ) -> EventContext<'a> {
346 EventContext {
347 rendered_views: &mut self.rendered_views,
348 dispatched_actions: Default::default(),
349 font_cache: &self.font_cache,
350 text_layout_cache: &self.text_layout_cache,
351 view_stack: Default::default(),
352 invalidated_views: Default::default(),
353 notify_count: 0,
354 app: cx,
355 }
356 }
357
358 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
359 let view = cx.root_view(self.window_id)?;
360 Some(json!({
361 "root_view": view.debug_json(cx),
362 "root_element": self.rendered_views.get(&view.id())
363 .map(|root_element| {
364 root_element.debug(&DebugContext {
365 rendered_views: &self.rendered_views,
366 font_cache: &self.font_cache,
367 app: cx,
368 })
369 })
370 }))
371 }
372}
373
374pub struct DispatchDirective {
375 pub dispatcher_view_id: Option<usize>,
376 pub action: Box<dyn Action>,
377}
378
379pub struct LayoutContext<'a> {
380 rendered_views: &'a mut HashMap<usize, ElementBox>,
381 parents: &'a mut HashMap<usize, usize>,
382 view_stack: Vec<usize>,
383 pub font_cache: &'a Arc<FontCache>,
384 pub font_system: Arc<dyn FontSystem>,
385 pub text_layout_cache: &'a TextLayoutCache,
386 pub asset_cache: &'a AssetCache,
387 pub app: &'a mut MutableAppContext,
388 pub refreshing: bool,
389 titlebar_height: f32,
390 hovered_region_ids: HashSet<MouseRegionId>,
391 clicked_region_id: Option<MouseRegionId>,
392}
393
394impl<'a> LayoutContext<'a> {
395 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
396 if let Some(parent_id) = self.view_stack.last() {
397 self.parents.insert(view_id, *parent_id);
398 }
399 self.view_stack.push(view_id);
400 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
401 let size = rendered_view.layout(constraint, self);
402 self.rendered_views.insert(view_id, rendered_view);
403 self.view_stack.pop();
404 size
405 }
406
407 pub fn render<F, V, T>(&mut self, handle: &ViewHandle<V>, f: F) -> T
408 where
409 F: FnOnce(&mut V, &mut RenderContext<V>) -> T,
410 V: View,
411 {
412 handle.update(self.app, |view, cx| {
413 let mut render_cx = RenderContext {
414 app: cx,
415 window_id: handle.window_id(),
416 view_id: handle.id(),
417 view_type: PhantomData,
418 titlebar_height: self.titlebar_height,
419 hovered_region_ids: self.hovered_region_ids.clone(),
420 clicked_region_id: self.clicked_region_id,
421 refreshing: self.refreshing,
422 };
423 f(view, &mut render_cx)
424 })
425 }
426}
427
428impl<'a> Deref for LayoutContext<'a> {
429 type Target = MutableAppContext;
430
431 fn deref(&self) -> &Self::Target {
432 self.app
433 }
434}
435
436impl<'a> DerefMut for LayoutContext<'a> {
437 fn deref_mut(&mut self) -> &mut Self::Target {
438 self.app
439 }
440}
441
442impl<'a> ReadView for LayoutContext<'a> {
443 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
444 self.app.read_view(handle)
445 }
446}
447
448impl<'a> ReadModel for LayoutContext<'a> {
449 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
450 self.app.read_model(handle)
451 }
452}
453
454impl<'a> UpgradeModelHandle for LayoutContext<'a> {
455 fn upgrade_model_handle<T: Entity>(
456 &self,
457 handle: &WeakModelHandle<T>,
458 ) -> Option<ModelHandle<T>> {
459 self.app.upgrade_model_handle(handle)
460 }
461
462 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
463 self.app.model_handle_is_upgradable(handle)
464 }
465
466 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
467 self.app.upgrade_any_model_handle(handle)
468 }
469}
470
471impl<'a> UpgradeViewHandle for LayoutContext<'a> {
472 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
473 self.app.upgrade_view_handle(handle)
474 }
475
476 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
477 self.app.upgrade_any_view_handle(handle)
478 }
479}
480
481pub struct PaintContext<'a> {
482 rendered_views: &'a mut HashMap<usize, ElementBox>,
483 view_stack: Vec<usize>,
484 pub scene: &'a mut Scene,
485 pub font_cache: &'a FontCache,
486 pub text_layout_cache: &'a TextLayoutCache,
487 pub app: &'a AppContext,
488}
489
490impl<'a> PaintContext<'a> {
491 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
492 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
493 self.view_stack.push(view_id);
494 tree.paint(origin, visible_bounds, self);
495 self.rendered_views.insert(view_id, tree);
496 self.view_stack.pop();
497 }
498 }
499
500 pub fn current_view_id(&self) -> usize {
501 *self.view_stack.last().unwrap()
502 }
503}
504
505impl<'a> Deref for PaintContext<'a> {
506 type Target = AppContext;
507
508 fn deref(&self) -> &Self::Target {
509 self.app
510 }
511}
512
513pub struct EventContext<'a> {
514 rendered_views: &'a mut HashMap<usize, ElementBox>,
515 dispatched_actions: Vec<DispatchDirective>,
516 pub font_cache: &'a FontCache,
517 pub text_layout_cache: &'a TextLayoutCache,
518 pub app: &'a mut MutableAppContext,
519 pub notify_count: usize,
520 view_stack: Vec<usize>,
521 invalidated_views: HashSet<usize>,
522}
523
524impl<'a> EventContext<'a> {
525 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
526 if let Some(mut element) = self.rendered_views.remove(&view_id) {
527 let result =
528 self.with_current_view(view_id, |this| element.dispatch_event(event, this));
529 self.rendered_views.insert(view_id, element);
530 result
531 } else {
532 false
533 }
534 }
535
536 fn with_current_view<F, T>(&mut self, view_id: usize, f: F) -> T
537 where
538 F: FnOnce(&mut Self) -> T,
539 {
540 self.view_stack.push(view_id);
541 let result = f(self);
542 self.view_stack.pop();
543 result
544 }
545
546 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
547 self.dispatched_actions.push(DispatchDirective {
548 dispatcher_view_id: self.view_stack.last().copied(),
549 action,
550 });
551 }
552
553 pub fn dispatch_action<A: Action>(&mut self, action: A) {
554 self.dispatch_any_action(Box::new(action));
555 }
556
557 pub fn notify(&mut self) {
558 self.notify_count += 1;
559 if let Some(view_id) = self.view_stack.last() {
560 self.invalidated_views.insert(*view_id);
561 }
562 }
563
564 pub fn notify_count(&self) -> usize {
565 self.notify_count
566 }
567}
568
569impl<'a> Deref for EventContext<'a> {
570 type Target = MutableAppContext;
571
572 fn deref(&self) -> &Self::Target {
573 self.app
574 }
575}
576
577impl<'a> DerefMut for EventContext<'a> {
578 fn deref_mut(&mut self) -> &mut Self::Target {
579 self.app
580 }
581}
582
583pub struct DebugContext<'a> {
584 rendered_views: &'a HashMap<usize, ElementBox>,
585 pub font_cache: &'a FontCache,
586 pub app: &'a AppContext,
587}
588
589#[derive(Clone, Copy, Debug, Eq, PartialEq)]
590pub enum Axis {
591 Horizontal,
592 Vertical,
593}
594
595impl Axis {
596 pub fn invert(self) -> Self {
597 match self {
598 Self::Horizontal => Self::Vertical,
599 Self::Vertical => Self::Horizontal,
600 }
601 }
602}
603
604impl ToJson for Axis {
605 fn to_json(&self) -> serde_json::Value {
606 match self {
607 Axis::Horizontal => json!("horizontal"),
608 Axis::Vertical => json!("vertical"),
609 }
610 }
611}
612
613pub trait Vector2FExt {
614 fn along(self, axis: Axis) -> f32;
615}
616
617impl Vector2FExt for Vector2F {
618 fn along(self, axis: Axis) -> f32 {
619 match axis {
620 Axis::Horizontal => self.x(),
621 Axis::Vertical => self.y(),
622 }
623 }
624}
625
626#[derive(Copy, Clone, Debug)]
627pub struct SizeConstraint {
628 pub min: Vector2F,
629 pub max: Vector2F,
630}
631
632impl SizeConstraint {
633 pub fn new(min: Vector2F, max: Vector2F) -> Self {
634 Self { min, max }
635 }
636
637 pub fn strict(size: Vector2F) -> Self {
638 Self {
639 min: size,
640 max: size,
641 }
642 }
643
644 pub fn strict_along(axis: Axis, max: f32) -> Self {
645 match axis {
646 Axis::Horizontal => Self {
647 min: vec2f(max, 0.0),
648 max: vec2f(max, f32::INFINITY),
649 },
650 Axis::Vertical => Self {
651 min: vec2f(0.0, max),
652 max: vec2f(f32::INFINITY, max),
653 },
654 }
655 }
656
657 pub fn max_along(&self, axis: Axis) -> f32 {
658 match axis {
659 Axis::Horizontal => self.max.x(),
660 Axis::Vertical => self.max.y(),
661 }
662 }
663
664 pub fn min_along(&self, axis: Axis) -> f32 {
665 match axis {
666 Axis::Horizontal => self.min.x(),
667 Axis::Vertical => self.min.y(),
668 }
669 }
670
671 pub fn constrain(&self, size: Vector2F) -> Vector2F {
672 vec2f(
673 size.x().min(self.max.x()).max(self.min.x()),
674 size.y().min(self.max.y()).max(self.min.y()),
675 )
676 }
677}
678
679impl ToJson for SizeConstraint {
680 fn to_json(&self) -> serde_json::Value {
681 json!({
682 "min": self.min.to_json(),
683 "max": self.max.to_json(),
684 })
685 }
686}
687
688pub struct ChildView {
689 view: AnyViewHandle,
690}
691
692impl ChildView {
693 pub fn new(view: impl Into<AnyViewHandle>) -> Self {
694 Self { view: view.into() }
695 }
696}
697
698impl Element for ChildView {
699 type LayoutState = ();
700 type PaintState = ();
701
702 fn layout(
703 &mut self,
704 constraint: SizeConstraint,
705 cx: &mut LayoutContext,
706 ) -> (Vector2F, Self::LayoutState) {
707 let size = cx.layout(self.view.id(), constraint);
708 (size, ())
709 }
710
711 fn paint(
712 &mut self,
713 bounds: RectF,
714 visible_bounds: RectF,
715 _: &mut Self::LayoutState,
716 cx: &mut PaintContext,
717 ) -> Self::PaintState {
718 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
719 }
720
721 fn dispatch_event(
722 &mut self,
723 event: &Event,
724 _: RectF,
725 _: RectF,
726 _: &mut Self::LayoutState,
727 _: &mut Self::PaintState,
728 cx: &mut EventContext,
729 ) -> bool {
730 cx.dispatch_event(self.view.id(), event)
731 }
732
733 fn debug(
734 &self,
735 bounds: RectF,
736 _: &Self::LayoutState,
737 _: &Self::PaintState,
738 cx: &DebugContext,
739 ) -> serde_json::Value {
740 json!({
741 "type": "ChildView",
742 "view_id": self.view.id(),
743 "bounds": bounds.to_json(),
744 "view": self.view.debug_json(cx.app),
745 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
746 view.debug(cx)
747 } else {
748 json!(null)
749 }
750 })
751 }
752}