1use crate::{
2 app::{AppContext, MutableAppContext, WindowInvalidation},
3 elements::Element,
4 font_cache::FontCache,
5 geometry::rect::RectF,
6 json::{self, ToJson},
7 platform::Event,
8 text_layout::TextLayoutCache,
9 Action, AnyModelHandle, AnyViewHandle, AnyWeakModelHandle, AssetCache, ElementBox,
10 ElementStateContext, Entity, FontSystem, ModelHandle, ReadModel, ReadView, Scene,
11 UpgradeModelHandle, UpgradeViewHandle, View, ViewHandle, WeakModelHandle, WeakViewHandle,
12};
13use pathfinder_geometry::vector::{vec2f, Vector2F};
14use serde_json::json;
15use std::{
16 collections::{HashMap, HashSet},
17 ops::{Deref, DerefMut},
18 sync::Arc,
19};
20
21pub struct Presenter {
22 window_id: usize,
23 pub(crate) rendered_views: HashMap<usize, ElementBox>,
24 parents: HashMap<usize, usize>,
25 font_cache: Arc<FontCache>,
26 text_layout_cache: TextLayoutCache,
27 asset_cache: Arc<AssetCache>,
28 last_mouse_moved_event: Option<Event>,
29 titlebar_height: f32,
30}
31
32impl Presenter {
33 pub fn new(
34 window_id: usize,
35 titlebar_height: f32,
36 font_cache: Arc<FontCache>,
37 text_layout_cache: TextLayoutCache,
38 asset_cache: Arc<AssetCache>,
39 cx: &mut MutableAppContext,
40 ) -> Self {
41 Self {
42 window_id,
43 rendered_views: cx.render_views(window_id, titlebar_height),
44 parents: HashMap::new(),
45 font_cache,
46 text_layout_cache,
47 asset_cache,
48 last_mouse_moved_event: None,
49 titlebar_height,
50 }
51 }
52
53 pub fn dispatch_path(&self, app: &AppContext) -> Vec<usize> {
54 if let Some(view_id) = app.focused_view_id(self.window_id) {
55 self.dispatch_path_from(view_id)
56 } else {
57 Vec::new()
58 }
59 }
60
61 pub(crate) fn dispatch_path_from(&self, mut view_id: usize) -> Vec<usize> {
62 let mut path = Vec::new();
63 path.push(view_id);
64 while let Some(parent_id) = self.parents.get(&view_id).copied() {
65 path.push(parent_id);
66 view_id = parent_id;
67 }
68 path.reverse();
69 path
70 }
71
72 pub fn invalidate(
73 &mut self,
74 invalidation: &mut WindowInvalidation,
75 cx: &mut MutableAppContext,
76 ) {
77 cx.start_frame();
78 for view_id in &invalidation.removed {
79 invalidation.updated.remove(&view_id);
80 self.rendered_views.remove(&view_id);
81 self.parents.remove(&view_id);
82 }
83 for view_id in &invalidation.updated {
84 self.rendered_views.insert(
85 *view_id,
86 cx.render_view(self.window_id, *view_id, self.titlebar_height, false)
87 .unwrap(),
88 );
89 }
90 }
91
92 pub fn refresh(&mut self, invalidation: &mut WindowInvalidation, cx: &mut MutableAppContext) {
93 self.invalidate(invalidation, cx);
94 for (view_id, view) in &mut self.rendered_views {
95 if !invalidation.updated.contains(view_id) {
96 *view = cx
97 .render_view(self.window_id, *view_id, self.titlebar_height, true)
98 .unwrap();
99 }
100 }
101 }
102
103 pub fn build_scene(
104 &mut self,
105 window_size: Vector2F,
106 scale_factor: f32,
107 refreshing: bool,
108 cx: &mut MutableAppContext,
109 ) -> Scene {
110 let mut scene = Scene::new(scale_factor);
111
112 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
113 self.layout(window_size, refreshing, cx);
114 let mut paint_cx = self.build_paint_context(&mut scene, cx);
115 paint_cx.paint(
116 root_view_id,
117 Vector2F::zero(),
118 RectF::new(Vector2F::zero(), window_size),
119 );
120 self.text_layout_cache.finish_frame();
121
122 if let Some(event) = self.last_mouse_moved_event.clone() {
123 self.dispatch_event(event, cx)
124 }
125 } else {
126 log::error!("could not find root_view_id for window {}", self.window_id);
127 }
128
129 scene
130 }
131
132 fn layout(&mut self, size: Vector2F, refreshing: bool, cx: &mut MutableAppContext) {
133 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
134 self.build_layout_context(refreshing, cx)
135 .layout(root_view_id, SizeConstraint::strict(size));
136 }
137 }
138
139 pub fn build_layout_context<'a>(
140 &'a mut self,
141 refreshing: bool,
142 cx: &'a mut MutableAppContext,
143 ) -> LayoutContext<'a> {
144 LayoutContext {
145 rendered_views: &mut self.rendered_views,
146 parents: &mut self.parents,
147 refreshing,
148 font_cache: &self.font_cache,
149 font_system: cx.platform().fonts(),
150 text_layout_cache: &self.text_layout_cache,
151 asset_cache: &self.asset_cache,
152 view_stack: Vec::new(),
153 app: cx,
154 }
155 }
156
157 pub fn build_paint_context<'a>(
158 &'a mut self,
159 scene: &'a mut Scene,
160 cx: &'a mut MutableAppContext,
161 ) -> PaintContext {
162 PaintContext {
163 scene,
164 font_cache: &self.font_cache,
165 text_layout_cache: &self.text_layout_cache,
166 rendered_views: &mut self.rendered_views,
167 app: cx,
168 }
169 }
170
171 pub fn dispatch_event(&mut self, event: Event, cx: &mut MutableAppContext) {
172 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
173 match event {
174 Event::MouseMoved { .. } => {
175 self.last_mouse_moved_event = Some(event.clone());
176 }
177 Event::LeftMouseDragged { position } => {
178 self.last_mouse_moved_event = Some(Event::MouseMoved {
179 position,
180 left_mouse_down: true,
181 });
182 }
183 _ => {}
184 }
185
186 let mut event_cx = self.build_event_context(cx);
187 event_cx.dispatch_event(root_view_id, &event);
188
189 let invalidated_views = event_cx.invalidated_views;
190 let dispatch_directives = event_cx.dispatched_actions;
191
192 for view_id in invalidated_views {
193 cx.notify_view(self.window_id, view_id);
194 }
195 for directive in dispatch_directives {
196 cx.dispatch_action_any(self.window_id, &directive.path, directive.action.as_ref());
197 }
198 }
199 }
200
201 pub fn build_event_context<'a>(
202 &'a mut self,
203 cx: &'a mut MutableAppContext,
204 ) -> EventContext<'a> {
205 EventContext {
206 rendered_views: &mut self.rendered_views,
207 dispatched_actions: Default::default(),
208 font_cache: &self.font_cache,
209 text_layout_cache: &self.text_layout_cache,
210 view_stack: Default::default(),
211 invalidated_views: Default::default(),
212 notify_count: 0,
213 app: cx,
214 }
215 }
216
217 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
218 let view = cx.root_view(self.window_id)?;
219 Some(json!({
220 "root_view": view.debug_json(cx),
221 "root_element": self.rendered_views.get(&view.id())
222 .map(|root_element| {
223 root_element.debug(&DebugContext {
224 rendered_views: &self.rendered_views,
225 font_cache: &self.font_cache,
226 app: cx,
227 })
228 })
229 }))
230 }
231}
232
233pub struct DispatchDirective {
234 pub path: Vec<usize>,
235 pub action: Box<dyn Action>,
236}
237
238pub struct LayoutContext<'a> {
239 rendered_views: &'a mut HashMap<usize, ElementBox>,
240 parents: &'a mut HashMap<usize, usize>,
241 view_stack: Vec<usize>,
242 pub refreshing: bool,
243 pub font_cache: &'a Arc<FontCache>,
244 pub font_system: Arc<dyn FontSystem>,
245 pub text_layout_cache: &'a TextLayoutCache,
246 pub asset_cache: &'a AssetCache,
247 pub app: &'a mut MutableAppContext,
248}
249
250impl<'a> LayoutContext<'a> {
251 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
252 if let Some(parent_id) = self.view_stack.last() {
253 self.parents.insert(view_id, *parent_id);
254 }
255 self.view_stack.push(view_id);
256 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
257 let size = rendered_view.layout(constraint, self);
258 self.rendered_views.insert(view_id, rendered_view);
259 self.view_stack.pop();
260 size
261 }
262}
263
264impl<'a> Deref for LayoutContext<'a> {
265 type Target = MutableAppContext;
266
267 fn deref(&self) -> &Self::Target {
268 self.app
269 }
270}
271
272impl<'a> DerefMut for LayoutContext<'a> {
273 fn deref_mut(&mut self) -> &mut Self::Target {
274 self.app
275 }
276}
277
278impl<'a> ReadView for LayoutContext<'a> {
279 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
280 self.app.read_view(handle)
281 }
282}
283
284impl<'a> ReadModel for LayoutContext<'a> {
285 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
286 self.app.read_model(handle)
287 }
288}
289
290impl<'a> UpgradeModelHandle for LayoutContext<'a> {
291 fn upgrade_model_handle<T: Entity>(
292 &self,
293 handle: &WeakModelHandle<T>,
294 ) -> Option<ModelHandle<T>> {
295 self.app.upgrade_model_handle(handle)
296 }
297
298 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
299 self.app.model_handle_is_upgradable(handle)
300 }
301
302 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
303 self.app.upgrade_any_model_handle(handle)
304 }
305}
306
307impl<'a> UpgradeViewHandle for LayoutContext<'a> {
308 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
309 self.app.upgrade_view_handle(handle)
310 }
311
312 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
313 self.app.upgrade_any_view_handle(handle)
314 }
315}
316
317impl<'a> ElementStateContext for LayoutContext<'a> {
318 fn current_view_id(&self) -> usize {
319 *self.view_stack.last().unwrap()
320 }
321}
322
323pub struct PaintContext<'a> {
324 rendered_views: &'a mut HashMap<usize, ElementBox>,
325 pub scene: &'a mut Scene,
326 pub font_cache: &'a FontCache,
327 pub text_layout_cache: &'a TextLayoutCache,
328 pub app: &'a AppContext,
329}
330
331impl<'a> PaintContext<'a> {
332 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
333 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
334 tree.paint(origin, visible_bounds, self);
335 self.rendered_views.insert(view_id, tree);
336 }
337 }
338}
339
340impl<'a> Deref for PaintContext<'a> {
341 type Target = AppContext;
342
343 fn deref(&self) -> &Self::Target {
344 self.app
345 }
346}
347
348pub struct EventContext<'a> {
349 rendered_views: &'a mut HashMap<usize, ElementBox>,
350 dispatched_actions: Vec<DispatchDirective>,
351 pub font_cache: &'a FontCache,
352 pub text_layout_cache: &'a TextLayoutCache,
353 pub app: &'a mut MutableAppContext,
354 pub notify_count: usize,
355 view_stack: Vec<usize>,
356 invalidated_views: HashSet<usize>,
357}
358
359impl<'a> EventContext<'a> {
360 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
361 if let Some(mut element) = self.rendered_views.remove(&view_id) {
362 self.view_stack.push(view_id);
363 let result = element.dispatch_event(event, self);
364 self.view_stack.pop();
365 self.rendered_views.insert(view_id, element);
366 result
367 } else {
368 false
369 }
370 }
371
372 pub fn dispatch_action<A: Action>(&mut self, action: A) {
373 self.dispatched_actions.push(DispatchDirective {
374 path: self.view_stack.clone(),
375 action: Box::new(action),
376 });
377 }
378
379 pub fn notify(&mut self) {
380 self.notify_count += 1;
381 if let Some(view_id) = self.view_stack.last() {
382 self.invalidated_views.insert(*view_id);
383 }
384 }
385
386 pub fn notify_count(&self) -> usize {
387 self.notify_count
388 }
389}
390
391impl<'a> Deref for EventContext<'a> {
392 type Target = MutableAppContext;
393
394 fn deref(&self) -> &Self::Target {
395 self.app
396 }
397}
398
399impl<'a> DerefMut for EventContext<'a> {
400 fn deref_mut(&mut self) -> &mut Self::Target {
401 self.app
402 }
403}
404
405pub struct DebugContext<'a> {
406 rendered_views: &'a HashMap<usize, ElementBox>,
407 pub font_cache: &'a FontCache,
408 pub app: &'a AppContext,
409}
410
411#[derive(Clone, Copy, Debug, Eq, PartialEq)]
412pub enum Axis {
413 Horizontal,
414 Vertical,
415}
416
417impl Axis {
418 pub fn invert(self) -> Self {
419 match self {
420 Self::Horizontal => Self::Vertical,
421 Self::Vertical => Self::Horizontal,
422 }
423 }
424}
425
426impl ToJson for Axis {
427 fn to_json(&self) -> serde_json::Value {
428 match self {
429 Axis::Horizontal => json!("horizontal"),
430 Axis::Vertical => json!("vertical"),
431 }
432 }
433}
434
435pub trait Vector2FExt {
436 fn along(self, axis: Axis) -> f32;
437}
438
439impl Vector2FExt for Vector2F {
440 fn along(self, axis: Axis) -> f32 {
441 match axis {
442 Axis::Horizontal => self.x(),
443 Axis::Vertical => self.y(),
444 }
445 }
446}
447
448#[derive(Copy, Clone, Debug)]
449pub struct SizeConstraint {
450 pub min: Vector2F,
451 pub max: Vector2F,
452}
453
454impl SizeConstraint {
455 pub fn new(min: Vector2F, max: Vector2F) -> Self {
456 Self { min, max }
457 }
458
459 pub fn strict(size: Vector2F) -> Self {
460 Self {
461 min: size,
462 max: size,
463 }
464 }
465
466 pub fn strict_along(axis: Axis, max: f32) -> Self {
467 match axis {
468 Axis::Horizontal => Self {
469 min: vec2f(max, 0.0),
470 max: vec2f(max, f32::INFINITY),
471 },
472 Axis::Vertical => Self {
473 min: vec2f(0.0, max),
474 max: vec2f(f32::INFINITY, max),
475 },
476 }
477 }
478
479 pub fn max_along(&self, axis: Axis) -> f32 {
480 match axis {
481 Axis::Horizontal => self.max.x(),
482 Axis::Vertical => self.max.y(),
483 }
484 }
485
486 pub fn min_along(&self, axis: Axis) -> f32 {
487 match axis {
488 Axis::Horizontal => self.min.x(),
489 Axis::Vertical => self.min.y(),
490 }
491 }
492
493 pub fn constrain(&self, size: Vector2F) -> Vector2F {
494 vec2f(
495 size.x().min(self.max.x()).max(self.min.x()),
496 size.y().min(self.max.y()).max(self.min.y()),
497 )
498 }
499}
500
501impl ToJson for SizeConstraint {
502 fn to_json(&self) -> serde_json::Value {
503 json!({
504 "min": self.min.to_json(),
505 "max": self.max.to_json(),
506 })
507 }
508}
509
510pub struct ChildView {
511 view: AnyViewHandle,
512}
513
514impl ChildView {
515 pub fn new(view: impl Into<AnyViewHandle>) -> Self {
516 Self { view: view.into() }
517 }
518}
519
520impl Element for ChildView {
521 type LayoutState = ();
522 type PaintState = ();
523
524 fn layout(
525 &mut self,
526 constraint: SizeConstraint,
527 cx: &mut LayoutContext,
528 ) -> (Vector2F, Self::LayoutState) {
529 let size = cx.layout(self.view.id(), constraint);
530 (size, ())
531 }
532
533 fn paint(
534 &mut self,
535 bounds: RectF,
536 visible_bounds: RectF,
537 _: &mut Self::LayoutState,
538 cx: &mut PaintContext,
539 ) -> Self::PaintState {
540 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
541 }
542
543 fn dispatch_event(
544 &mut self,
545 event: &Event,
546 _: RectF,
547 _: RectF,
548 _: &mut Self::LayoutState,
549 _: &mut Self::PaintState,
550 cx: &mut EventContext,
551 ) -> bool {
552 cx.dispatch_event(self.view.id(), event)
553 }
554
555 fn debug(
556 &self,
557 bounds: RectF,
558 _: &Self::LayoutState,
559 _: &Self::PaintState,
560 cx: &DebugContext,
561 ) -> serde_json::Value {
562 json!({
563 "type": "ChildView",
564 "view_id": self.view.id(),
565 "bounds": bounds.to_json(),
566 "view": self.view.debug_json(cx.app),
567 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
568 view.debug(cx)
569 } else {
570 json!(null)
571 }
572 })
573 }
574}