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