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 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 cursor_styles: Vec<(RectF, CursorStyle)>,
26 font_cache: Arc<FontCache>,
27 text_layout_cache: TextLayoutCache,
28 asset_cache: Arc<AssetCache>,
29 last_mouse_moved_event: Option<Event>,
30 titlebar_height: f32,
31}
32
33impl Presenter {
34 pub fn new(
35 window_id: usize,
36 titlebar_height: f32,
37 font_cache: Arc<FontCache>,
38 text_layout_cache: TextLayoutCache,
39 asset_cache: Arc<AssetCache>,
40 cx: &mut MutableAppContext,
41 ) -> Self {
42 Self {
43 window_id,
44 rendered_views: cx.render_views(window_id, titlebar_height),
45 parents: HashMap::new(),
46 cursor_styles: Default::default(),
47 font_cache,
48 text_layout_cache,
49 asset_cache,
50 last_mouse_moved_event: None,
51 titlebar_height,
52 }
53 }
54
55 pub fn dispatch_path(&self, app: &AppContext) -> Vec<usize> {
56 if let Some(view_id) = app.focused_view_id(self.window_id) {
57 self.dispatch_path_from(view_id)
58 } else {
59 Vec::new()
60 }
61 }
62
63 pub(crate) fn dispatch_path_from(&self, mut view_id: usize) -> Vec<usize> {
64 let mut path = Vec::new();
65 path.push(view_id);
66 while let Some(parent_id) = self.parents.get(&view_id).copied() {
67 path.push(parent_id);
68 view_id = parent_id;
69 }
70 path.reverse();
71 path
72 }
73
74 pub fn invalidate(
75 &mut self,
76 invalidation: &mut WindowInvalidation,
77 cx: &mut MutableAppContext,
78 ) {
79 cx.start_frame();
80 for view_id in &invalidation.removed {
81 invalidation.updated.remove(&view_id);
82 self.rendered_views.remove(&view_id);
83 self.parents.remove(&view_id);
84 }
85 for view_id in &invalidation.updated {
86 self.rendered_views.insert(
87 *view_id,
88 cx.render_view(self.window_id, *view_id, self.titlebar_height, false)
89 .unwrap(),
90 );
91 }
92 }
93
94 pub fn refresh(&mut self, invalidation: &mut WindowInvalidation, cx: &mut MutableAppContext) {
95 self.invalidate(invalidation, cx);
96 for (view_id, view) in &mut self.rendered_views {
97 if !invalidation.updated.contains(view_id) {
98 *view = cx
99 .render_view(self.window_id, *view_id, self.titlebar_height, true)
100 .unwrap();
101 }
102 }
103 }
104
105 pub fn build_scene(
106 &mut self,
107 window_size: Vector2F,
108 scale_factor: f32,
109 refreshing: bool,
110 cx: &mut MutableAppContext,
111 ) -> Scene {
112 let mut scene = Scene::new(scale_factor);
113
114 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
115 self.layout(window_size, refreshing, cx);
116 let mut paint_cx = self.build_paint_context(&mut scene, cx);
117 paint_cx.paint(
118 root_view_id,
119 Vector2F::zero(),
120 RectF::new(Vector2F::zero(), window_size),
121 );
122 self.text_layout_cache.finish_frame();
123 self.cursor_styles = scene.cursor_styles();
124
125 if let Some(event) = self.last_mouse_moved_event.clone() {
126 self.dispatch_event(event, cx)
127 }
128 } else {
129 log::error!("could not find root_view_id for window {}", self.window_id);
130 }
131
132 scene
133 }
134
135 fn layout(&mut self, size: Vector2F, refreshing: bool, cx: &mut MutableAppContext) {
136 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
137 self.build_layout_context(refreshing, cx)
138 .layout(root_view_id, SizeConstraint::strict(size));
139 }
140 }
141
142 pub fn build_layout_context<'a>(
143 &'a mut self,
144 refreshing: bool,
145 cx: &'a mut MutableAppContext,
146 ) -> LayoutContext<'a> {
147 LayoutContext {
148 rendered_views: &mut self.rendered_views,
149 parents: &mut self.parents,
150 refreshing,
151 font_cache: &self.font_cache,
152 font_system: cx.platform().fonts(),
153 text_layout_cache: &self.text_layout_cache,
154 asset_cache: &self.asset_cache,
155 view_stack: Vec::new(),
156 app: cx,
157 }
158 }
159
160 pub fn build_paint_context<'a>(
161 &'a mut self,
162 scene: &'a mut Scene,
163 cx: &'a mut MutableAppContext,
164 ) -> PaintContext {
165 PaintContext {
166 scene,
167 font_cache: &self.font_cache,
168 text_layout_cache: &self.text_layout_cache,
169 rendered_views: &mut self.rendered_views,
170 app: cx,
171 }
172 }
173
174 pub fn dispatch_event(&mut self, event: Event, cx: &mut MutableAppContext) {
175 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
176 match event {
177 Event::MouseMoved {
178 position,
179 left_mouse_down,
180 } => {
181 self.last_mouse_moved_event = Some(event.clone());
182
183 if !left_mouse_down {
184 cx.platform().set_cursor_style(CursorStyle::Arrow);
185 for (bounds, style) in self.cursor_styles.iter().rev() {
186 if bounds.contains_point(position) {
187 cx.platform().set_cursor_style(*style);
188 break;
189 }
190 }
191 }
192 }
193 Event::LeftMouseDragged { position } => {
194 self.last_mouse_moved_event = Some(Event::MouseMoved {
195 position,
196 left_mouse_down: true,
197 });
198 }
199 _ => {}
200 }
201
202 let mut event_cx = self.build_event_context(cx);
203 event_cx.dispatch_event(root_view_id, &event);
204
205 let invalidated_views = event_cx.invalidated_views;
206 let dispatch_directives = event_cx.dispatched_actions;
207
208 for view_id in invalidated_views {
209 cx.notify_view(self.window_id, view_id);
210 }
211 for directive in dispatch_directives {
212 cx.dispatch_action_any(self.window_id, &directive.path, directive.action.as_ref());
213 }
214 }
215 }
216
217 pub fn build_event_context<'a>(
218 &'a mut self,
219 cx: &'a mut MutableAppContext,
220 ) -> EventContext<'a> {
221 EventContext {
222 rendered_views: &mut self.rendered_views,
223 dispatched_actions: Default::default(),
224 font_cache: &self.font_cache,
225 text_layout_cache: &self.text_layout_cache,
226 view_stack: Default::default(),
227 invalidated_views: Default::default(),
228 notify_count: 0,
229 app: cx,
230 }
231 }
232
233 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
234 let view = cx.root_view(self.window_id)?;
235 Some(json!({
236 "root_view": view.debug_json(cx),
237 "root_element": self.rendered_views.get(&view.id())
238 .map(|root_element| {
239 root_element.debug(&DebugContext {
240 rendered_views: &self.rendered_views,
241 font_cache: &self.font_cache,
242 app: cx,
243 })
244 })
245 }))
246 }
247}
248
249pub struct DispatchDirective {
250 pub path: Vec<usize>,
251 pub action: Box<dyn Action>,
252}
253
254pub struct LayoutContext<'a> {
255 rendered_views: &'a mut HashMap<usize, ElementBox>,
256 parents: &'a mut HashMap<usize, usize>,
257 view_stack: Vec<usize>,
258 pub refreshing: bool,
259 pub font_cache: &'a Arc<FontCache>,
260 pub font_system: Arc<dyn FontSystem>,
261 pub text_layout_cache: &'a TextLayoutCache,
262 pub asset_cache: &'a AssetCache,
263 pub app: &'a mut MutableAppContext,
264}
265
266impl<'a> LayoutContext<'a> {
267 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
268 if let Some(parent_id) = self.view_stack.last() {
269 self.parents.insert(view_id, *parent_id);
270 }
271 self.view_stack.push(view_id);
272 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
273 let size = rendered_view.layout(constraint, self);
274 self.rendered_views.insert(view_id, rendered_view);
275 self.view_stack.pop();
276 size
277 }
278}
279
280impl<'a> Deref for LayoutContext<'a> {
281 type Target = MutableAppContext;
282
283 fn deref(&self) -> &Self::Target {
284 self.app
285 }
286}
287
288impl<'a> DerefMut for LayoutContext<'a> {
289 fn deref_mut(&mut self) -> &mut Self::Target {
290 self.app
291 }
292}
293
294impl<'a> ReadView for LayoutContext<'a> {
295 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
296 self.app.read_view(handle)
297 }
298}
299
300impl<'a> ReadModel for LayoutContext<'a> {
301 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
302 self.app.read_model(handle)
303 }
304}
305
306impl<'a> UpgradeModelHandle for LayoutContext<'a> {
307 fn upgrade_model_handle<T: Entity>(
308 &self,
309 handle: &WeakModelHandle<T>,
310 ) -> Option<ModelHandle<T>> {
311 self.app.upgrade_model_handle(handle)
312 }
313
314 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
315 self.app.model_handle_is_upgradable(handle)
316 }
317
318 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
319 self.app.upgrade_any_model_handle(handle)
320 }
321}
322
323impl<'a> UpgradeViewHandle for LayoutContext<'a> {
324 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
325 self.app.upgrade_view_handle(handle)
326 }
327
328 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
329 self.app.upgrade_any_view_handle(handle)
330 }
331}
332
333impl<'a> ElementStateContext for LayoutContext<'a> {
334 fn current_view_id(&self) -> usize {
335 *self.view_stack.last().unwrap()
336 }
337}
338
339pub struct PaintContext<'a> {
340 rendered_views: &'a mut HashMap<usize, ElementBox>,
341 pub scene: &'a mut Scene,
342 pub font_cache: &'a FontCache,
343 pub text_layout_cache: &'a TextLayoutCache,
344 pub app: &'a AppContext,
345}
346
347impl<'a> PaintContext<'a> {
348 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
349 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
350 tree.paint(origin, visible_bounds, self);
351 self.rendered_views.insert(view_id, tree);
352 }
353 }
354}
355
356impl<'a> Deref for PaintContext<'a> {
357 type Target = AppContext;
358
359 fn deref(&self) -> &Self::Target {
360 self.app
361 }
362}
363
364pub struct EventContext<'a> {
365 rendered_views: &'a mut HashMap<usize, ElementBox>,
366 dispatched_actions: Vec<DispatchDirective>,
367 pub font_cache: &'a FontCache,
368 pub text_layout_cache: &'a TextLayoutCache,
369 pub app: &'a mut MutableAppContext,
370 pub notify_count: usize,
371 view_stack: Vec<usize>,
372 invalidated_views: HashSet<usize>,
373}
374
375impl<'a> EventContext<'a> {
376 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
377 if let Some(mut element) = self.rendered_views.remove(&view_id) {
378 self.view_stack.push(view_id);
379 let result = element.dispatch_event(event, self);
380 self.view_stack.pop();
381 self.rendered_views.insert(view_id, element);
382 result
383 } else {
384 false
385 }
386 }
387
388 pub fn dispatch_action<A: Action>(&mut self, action: A) {
389 self.dispatched_actions.push(DispatchDirective {
390 path: self.view_stack.clone(),
391 action: Box::new(action),
392 });
393 }
394
395 pub fn notify(&mut self) {
396 self.notify_count += 1;
397 if let Some(view_id) = self.view_stack.last() {
398 self.invalidated_views.insert(*view_id);
399 }
400 }
401
402 pub fn notify_count(&self) -> usize {
403 self.notify_count
404 }
405}
406
407impl<'a> Deref for EventContext<'a> {
408 type Target = MutableAppContext;
409
410 fn deref(&self) -> &Self::Target {
411 self.app
412 }
413}
414
415impl<'a> DerefMut for EventContext<'a> {
416 fn deref_mut(&mut self) -> &mut Self::Target {
417 self.app
418 }
419}
420
421pub struct DebugContext<'a> {
422 rendered_views: &'a HashMap<usize, ElementBox>,
423 pub font_cache: &'a FontCache,
424 pub app: &'a AppContext,
425}
426
427#[derive(Clone, Copy, Debug, Eq, PartialEq)]
428pub enum Axis {
429 Horizontal,
430 Vertical,
431}
432
433impl Axis {
434 pub fn invert(self) -> Self {
435 match self {
436 Self::Horizontal => Self::Vertical,
437 Self::Vertical => Self::Horizontal,
438 }
439 }
440}
441
442impl ToJson for Axis {
443 fn to_json(&self) -> serde_json::Value {
444 match self {
445 Axis::Horizontal => json!("horizontal"),
446 Axis::Vertical => json!("vertical"),
447 }
448 }
449}
450
451pub trait Vector2FExt {
452 fn along(self, axis: Axis) -> f32;
453}
454
455impl Vector2FExt for Vector2F {
456 fn along(self, axis: Axis) -> f32 {
457 match axis {
458 Axis::Horizontal => self.x(),
459 Axis::Vertical => self.y(),
460 }
461 }
462}
463
464#[derive(Copy, Clone, Debug)]
465pub struct SizeConstraint {
466 pub min: Vector2F,
467 pub max: Vector2F,
468}
469
470impl SizeConstraint {
471 pub fn new(min: Vector2F, max: Vector2F) -> Self {
472 Self { min, max }
473 }
474
475 pub fn strict(size: Vector2F) -> Self {
476 Self {
477 min: size,
478 max: size,
479 }
480 }
481
482 pub fn strict_along(axis: Axis, max: f32) -> Self {
483 match axis {
484 Axis::Horizontal => Self {
485 min: vec2f(max, 0.0),
486 max: vec2f(max, f32::INFINITY),
487 },
488 Axis::Vertical => Self {
489 min: vec2f(0.0, max),
490 max: vec2f(f32::INFINITY, max),
491 },
492 }
493 }
494
495 pub fn max_along(&self, axis: Axis) -> f32 {
496 match axis {
497 Axis::Horizontal => self.max.x(),
498 Axis::Vertical => self.max.y(),
499 }
500 }
501
502 pub fn min_along(&self, axis: Axis) -> f32 {
503 match axis {
504 Axis::Horizontal => self.min.x(),
505 Axis::Vertical => self.min.y(),
506 }
507 }
508
509 pub fn constrain(&self, size: Vector2F) -> Vector2F {
510 vec2f(
511 size.x().min(self.max.x()).max(self.min.x()),
512 size.y().min(self.max.y()).max(self.min.y()),
513 )
514 }
515}
516
517impl ToJson for SizeConstraint {
518 fn to_json(&self) -> serde_json::Value {
519 json!({
520 "min": self.min.to_json(),
521 "max": self.max.to_json(),
522 })
523 }
524}
525
526pub struct ChildView {
527 view: AnyViewHandle,
528}
529
530impl ChildView {
531 pub fn new(view: impl Into<AnyViewHandle>) -> Self {
532 Self { view: view.into() }
533 }
534}
535
536impl Element for ChildView {
537 type LayoutState = ();
538 type PaintState = ();
539
540 fn layout(
541 &mut self,
542 constraint: SizeConstraint,
543 cx: &mut LayoutContext,
544 ) -> (Vector2F, Self::LayoutState) {
545 let size = cx.layout(self.view.id(), constraint);
546 (size, ())
547 }
548
549 fn paint(
550 &mut self,
551 bounds: RectF,
552 visible_bounds: RectF,
553 _: &mut Self::LayoutState,
554 cx: &mut PaintContext,
555 ) -> Self::PaintState {
556 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
557 }
558
559 fn dispatch_event(
560 &mut self,
561 event: &Event,
562 _: RectF,
563 _: RectF,
564 _: &mut Self::LayoutState,
565 _: &mut Self::PaintState,
566 cx: &mut EventContext,
567 ) -> bool {
568 cx.dispatch_event(self.view.id(), event)
569 }
570
571 fn debug(
572 &self,
573 bounds: RectF,
574 _: &Self::LayoutState,
575 _: &Self::PaintState,
576 cx: &DebugContext,
577 ) -> serde_json::Value {
578 json!({
579 "type": "ChildView",
580 "view_id": self.view.id(),
581 "bounds": bounds.to_json(),
582 "view": self.view.debug_json(cx.app),
583 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
584 view.debug(cx)
585 } else {
586 json!(null)
587 }
588 })
589 }
590}