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 cx.root_view_id(self.window_id)
213 .and_then(|root_view_id| self.rendered_views.get(&root_view_id))
214 .map(|root_element| {
215 root_element.debug(&DebugContext {
216 rendered_views: &self.rendered_views,
217 font_cache: &self.font_cache,
218 app: cx,
219 })
220 })
221 }
222}
223
224pub struct DispatchDirective {
225 pub path: Vec<usize>,
226 pub action: Box<dyn Action>,
227}
228
229pub struct LayoutContext<'a> {
230 rendered_views: &'a mut HashMap<usize, ElementBox>,
231 parents: &'a mut HashMap<usize, usize>,
232 view_stack: Vec<usize>,
233 pub refreshing: bool,
234 pub font_cache: &'a Arc<FontCache>,
235 pub font_system: Arc<dyn FontSystem>,
236 pub text_layout_cache: &'a TextLayoutCache,
237 pub asset_cache: &'a AssetCache,
238 pub app: &'a mut MutableAppContext,
239}
240
241impl<'a> LayoutContext<'a> {
242 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
243 if let Some(parent_id) = self.view_stack.last() {
244 self.parents.insert(view_id, *parent_id);
245 }
246 self.view_stack.push(view_id);
247 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
248 let size = rendered_view.layout(constraint, self);
249 self.rendered_views.insert(view_id, rendered_view);
250 self.view_stack.pop();
251 size
252 }
253}
254
255impl<'a> Deref for LayoutContext<'a> {
256 type Target = MutableAppContext;
257
258 fn deref(&self) -> &Self::Target {
259 self.app
260 }
261}
262
263impl<'a> DerefMut for LayoutContext<'a> {
264 fn deref_mut(&mut self) -> &mut Self::Target {
265 self.app
266 }
267}
268
269impl<'a> ReadView for LayoutContext<'a> {
270 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
271 self.app.read_view(handle)
272 }
273}
274
275impl<'a> ReadModel for LayoutContext<'a> {
276 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
277 self.app.read_model(handle)
278 }
279}
280
281impl<'a> UpgradeModelHandle for LayoutContext<'a> {
282 fn upgrade_model_handle<T: Entity>(
283 &self,
284 handle: &WeakModelHandle<T>,
285 ) -> Option<ModelHandle<T>> {
286 self.app.upgrade_model_handle(handle)
287 }
288
289 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
290 self.app.model_handle_is_upgradable(handle)
291 }
292
293 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
294 self.app.upgrade_any_model_handle(handle)
295 }
296}
297
298impl<'a> UpgradeViewHandle for LayoutContext<'a> {
299 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
300 self.app.upgrade_view_handle(handle)
301 }
302
303 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
304 self.app.upgrade_any_view_handle(handle)
305 }
306}
307
308impl<'a> ElementStateContext for LayoutContext<'a> {
309 fn current_view_id(&self) -> usize {
310 *self.view_stack.last().unwrap()
311 }
312}
313
314pub struct PaintContext<'a> {
315 rendered_views: &'a mut HashMap<usize, ElementBox>,
316 pub scene: &'a mut Scene,
317 pub font_cache: &'a FontCache,
318 pub text_layout_cache: &'a TextLayoutCache,
319 pub app: &'a AppContext,
320}
321
322impl<'a> PaintContext<'a> {
323 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
324 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
325 tree.paint(origin, visible_bounds, self);
326 self.rendered_views.insert(view_id, tree);
327 }
328 }
329}
330
331impl<'a> Deref for PaintContext<'a> {
332 type Target = AppContext;
333
334 fn deref(&self) -> &Self::Target {
335 self.app
336 }
337}
338
339pub struct EventContext<'a> {
340 rendered_views: &'a mut HashMap<usize, ElementBox>,
341 dispatched_actions: Vec<DispatchDirective>,
342 pub font_cache: &'a FontCache,
343 pub text_layout_cache: &'a TextLayoutCache,
344 pub app: &'a mut MutableAppContext,
345 pub notify_count: usize,
346 view_stack: Vec<usize>,
347 invalidated_views: HashSet<usize>,
348}
349
350impl<'a> EventContext<'a> {
351 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
352 if let Some(mut element) = self.rendered_views.remove(&view_id) {
353 self.view_stack.push(view_id);
354 let result = element.dispatch_event(event, self);
355 self.view_stack.pop();
356 self.rendered_views.insert(view_id, element);
357 result
358 } else {
359 false
360 }
361 }
362
363 pub fn dispatch_action<A: Action>(&mut self, action: A) {
364 self.dispatched_actions.push(DispatchDirective {
365 path: self.view_stack.clone(),
366 action: Box::new(action),
367 });
368 }
369
370 pub fn notify(&mut self) {
371 self.notify_count += 1;
372 if let Some(view_id) = self.view_stack.last() {
373 self.invalidated_views.insert(*view_id);
374 }
375 }
376
377 pub fn notify_count(&self) -> usize {
378 self.notify_count
379 }
380}
381
382impl<'a> Deref for EventContext<'a> {
383 type Target = MutableAppContext;
384
385 fn deref(&self) -> &Self::Target {
386 self.app
387 }
388}
389
390impl<'a> DerefMut for EventContext<'a> {
391 fn deref_mut(&mut self) -> &mut Self::Target {
392 self.app
393 }
394}
395
396pub struct DebugContext<'a> {
397 rendered_views: &'a HashMap<usize, ElementBox>,
398 pub font_cache: &'a FontCache,
399 pub app: &'a AppContext,
400}
401
402#[derive(Clone, Copy, Debug, Eq, PartialEq)]
403pub enum Axis {
404 Horizontal,
405 Vertical,
406}
407
408impl Axis {
409 pub fn invert(self) -> Self {
410 match self {
411 Self::Horizontal => Self::Vertical,
412 Self::Vertical => Self::Horizontal,
413 }
414 }
415}
416
417impl ToJson for Axis {
418 fn to_json(&self) -> serde_json::Value {
419 match self {
420 Axis::Horizontal => json!("horizontal"),
421 Axis::Vertical => json!("vertical"),
422 }
423 }
424}
425
426pub trait Vector2FExt {
427 fn along(self, axis: Axis) -> f32;
428}
429
430impl Vector2FExt for Vector2F {
431 fn along(self, axis: Axis) -> f32 {
432 match axis {
433 Axis::Horizontal => self.x(),
434 Axis::Vertical => self.y(),
435 }
436 }
437}
438
439#[derive(Copy, Clone, Debug)]
440pub struct SizeConstraint {
441 pub min: Vector2F,
442 pub max: Vector2F,
443}
444
445impl SizeConstraint {
446 pub fn new(min: Vector2F, max: Vector2F) -> Self {
447 Self { min, max }
448 }
449
450 pub fn strict(size: Vector2F) -> Self {
451 Self {
452 min: size,
453 max: size,
454 }
455 }
456
457 pub fn strict_along(axis: Axis, max: f32) -> Self {
458 match axis {
459 Axis::Horizontal => Self {
460 min: vec2f(max, 0.0),
461 max: vec2f(max, f32::INFINITY),
462 },
463 Axis::Vertical => Self {
464 min: vec2f(0.0, max),
465 max: vec2f(f32::INFINITY, max),
466 },
467 }
468 }
469
470 pub fn max_along(&self, axis: Axis) -> f32 {
471 match axis {
472 Axis::Horizontal => self.max.x(),
473 Axis::Vertical => self.max.y(),
474 }
475 }
476
477 pub fn min_along(&self, axis: Axis) -> f32 {
478 match axis {
479 Axis::Horizontal => self.min.x(),
480 Axis::Vertical => self.min.y(),
481 }
482 }
483
484 pub fn constrain(&self, size: Vector2F) -> Vector2F {
485 vec2f(
486 size.x().min(self.max.x()).max(self.min.x()),
487 size.y().min(self.max.y()).max(self.min.y()),
488 )
489 }
490}
491
492impl ToJson for SizeConstraint {
493 fn to_json(&self) -> serde_json::Value {
494 json!({
495 "min": self.min.to_json(),
496 "max": self.max.to_json(),
497 })
498 }
499}
500
501pub struct ChildView {
502 view: AnyViewHandle,
503}
504
505impl ChildView {
506 pub fn new(view: impl Into<AnyViewHandle>) -> Self {
507 Self { view: view.into() }
508 }
509}
510
511impl Element for ChildView {
512 type LayoutState = ();
513 type PaintState = ();
514
515 fn layout(
516 &mut self,
517 constraint: SizeConstraint,
518 cx: &mut LayoutContext,
519 ) -> (Vector2F, Self::LayoutState) {
520 let size = cx.layout(self.view.id(), constraint);
521 (size, ())
522 }
523
524 fn paint(
525 &mut self,
526 bounds: RectF,
527 visible_bounds: RectF,
528 _: &mut Self::LayoutState,
529 cx: &mut PaintContext,
530 ) -> Self::PaintState {
531 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
532 }
533
534 fn dispatch_event(
535 &mut self,
536 event: &Event,
537 _: RectF,
538 _: RectF,
539 _: &mut Self::LayoutState,
540 _: &mut Self::PaintState,
541 cx: &mut EventContext,
542 ) -> bool {
543 cx.dispatch_event(self.view.id(), event)
544 }
545
546 fn debug(
547 &self,
548 bounds: RectF,
549 _: &Self::LayoutState,
550 _: &Self::PaintState,
551 cx: &DebugContext,
552 ) -> serde_json::Value {
553 json!({
554 "type": "ChildView",
555 "view_id": self.view.id(),
556 "bounds": bounds.to_json(),
557 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
558 view.debug(cx)
559 } else {
560 json!(null)
561 }
562 })
563 }
564}