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 cx.window_is_active(self.window_id) {
126 if let Some(event) = self.last_mouse_moved_event.clone() {
127 self.dispatch_event(event, cx)
128 }
129 }
130 } else {
131 log::error!("could not find root_view_id for window {}", self.window_id);
132 }
133
134 scene
135 }
136
137 fn layout(&mut self, size: Vector2F, refreshing: bool, cx: &mut MutableAppContext) {
138 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
139 self.build_layout_context(refreshing, cx)
140 .layout(root_view_id, SizeConstraint::strict(size));
141 }
142 }
143
144 pub fn build_layout_context<'a>(
145 &'a mut self,
146 refreshing: bool,
147 cx: &'a mut MutableAppContext,
148 ) -> LayoutContext<'a> {
149 LayoutContext {
150 rendered_views: &mut self.rendered_views,
151 parents: &mut self.parents,
152 refreshing,
153 font_cache: &self.font_cache,
154 font_system: cx.platform().fonts(),
155 text_layout_cache: &self.text_layout_cache,
156 asset_cache: &self.asset_cache,
157 view_stack: Vec::new(),
158 app: cx,
159 }
160 }
161
162 pub fn build_paint_context<'a>(
163 &'a mut self,
164 scene: &'a mut Scene,
165 cx: &'a mut MutableAppContext,
166 ) -> PaintContext {
167 PaintContext {
168 scene,
169 font_cache: &self.font_cache,
170 text_layout_cache: &self.text_layout_cache,
171 rendered_views: &mut self.rendered_views,
172 app: cx,
173 }
174 }
175
176 pub fn dispatch_event(&mut self, event: Event, cx: &mut MutableAppContext) {
177 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
178 match event {
179 Event::MouseMoved {
180 position,
181 left_mouse_down,
182 } => {
183 self.last_mouse_moved_event = Some(event.clone());
184
185 if !left_mouse_down {
186 let mut style_to_assign = CursorStyle::Arrow;
187 for (bounds, style) in self.cursor_styles.iter().rev() {
188 if bounds.contains_point(position) {
189 style_to_assign = *style;
190 break;
191 }
192 }
193 cx.platform().set_cursor_style(style_to_assign);
194 }
195 }
196 Event::LeftMouseDragged { position } => {
197 self.last_mouse_moved_event = Some(Event::MouseMoved {
198 position,
199 left_mouse_down: true,
200 });
201 }
202 _ => {}
203 }
204
205 let mut event_cx = self.build_event_context(cx);
206 event_cx.dispatch_event(root_view_id, &event);
207
208 let invalidated_views = event_cx.invalidated_views;
209 let dispatch_directives = event_cx.dispatched_actions;
210
211 for view_id in invalidated_views {
212 cx.notify_view(self.window_id, view_id);
213 }
214 for directive in dispatch_directives {
215 cx.dispatch_action_any(self.window_id, &directive.path, directive.action.as_ref());
216 }
217 }
218 }
219
220 pub fn build_event_context<'a>(
221 &'a mut self,
222 cx: &'a mut MutableAppContext,
223 ) -> EventContext<'a> {
224 EventContext {
225 rendered_views: &mut self.rendered_views,
226 dispatched_actions: Default::default(),
227 font_cache: &self.font_cache,
228 text_layout_cache: &self.text_layout_cache,
229 view_stack: Default::default(),
230 invalidated_views: Default::default(),
231 notify_count: 0,
232 app: cx,
233 }
234 }
235
236 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
237 let view = cx.root_view(self.window_id)?;
238 Some(json!({
239 "root_view": view.debug_json(cx),
240 "root_element": self.rendered_views.get(&view.id())
241 .map(|root_element| {
242 root_element.debug(&DebugContext {
243 rendered_views: &self.rendered_views,
244 font_cache: &self.font_cache,
245 app: cx,
246 })
247 })
248 }))
249 }
250}
251
252pub struct DispatchDirective {
253 pub path: Vec<usize>,
254 pub action: Box<dyn Action>,
255}
256
257pub struct LayoutContext<'a> {
258 rendered_views: &'a mut HashMap<usize, ElementBox>,
259 parents: &'a mut HashMap<usize, usize>,
260 view_stack: Vec<usize>,
261 pub refreshing: bool,
262 pub font_cache: &'a Arc<FontCache>,
263 pub font_system: Arc<dyn FontSystem>,
264 pub text_layout_cache: &'a TextLayoutCache,
265 pub asset_cache: &'a AssetCache,
266 pub app: &'a mut MutableAppContext,
267}
268
269impl<'a> LayoutContext<'a> {
270 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
271 if let Some(parent_id) = self.view_stack.last() {
272 self.parents.insert(view_id, *parent_id);
273 }
274 self.view_stack.push(view_id);
275 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
276 let size = rendered_view.layout(constraint, self);
277 self.rendered_views.insert(view_id, rendered_view);
278 self.view_stack.pop();
279 size
280 }
281}
282
283impl<'a> Deref for LayoutContext<'a> {
284 type Target = MutableAppContext;
285
286 fn deref(&self) -> &Self::Target {
287 self.app
288 }
289}
290
291impl<'a> DerefMut for LayoutContext<'a> {
292 fn deref_mut(&mut self) -> &mut Self::Target {
293 self.app
294 }
295}
296
297impl<'a> ReadView for LayoutContext<'a> {
298 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
299 self.app.read_view(handle)
300 }
301}
302
303impl<'a> ReadModel for LayoutContext<'a> {
304 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
305 self.app.read_model(handle)
306 }
307}
308
309impl<'a> UpgradeModelHandle for LayoutContext<'a> {
310 fn upgrade_model_handle<T: Entity>(
311 &self,
312 handle: &WeakModelHandle<T>,
313 ) -> Option<ModelHandle<T>> {
314 self.app.upgrade_model_handle(handle)
315 }
316
317 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
318 self.app.model_handle_is_upgradable(handle)
319 }
320
321 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
322 self.app.upgrade_any_model_handle(handle)
323 }
324}
325
326impl<'a> UpgradeViewHandle for LayoutContext<'a> {
327 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
328 self.app.upgrade_view_handle(handle)
329 }
330
331 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
332 self.app.upgrade_any_view_handle(handle)
333 }
334}
335
336impl<'a> ElementStateContext for LayoutContext<'a> {
337 fn current_view_id(&self) -> usize {
338 *self.view_stack.last().unwrap()
339 }
340}
341
342pub struct PaintContext<'a> {
343 rendered_views: &'a mut HashMap<usize, ElementBox>,
344 pub scene: &'a mut Scene,
345 pub font_cache: &'a FontCache,
346 pub text_layout_cache: &'a TextLayoutCache,
347 pub app: &'a AppContext,
348}
349
350impl<'a> PaintContext<'a> {
351 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
352 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
353 tree.paint(origin, visible_bounds, self);
354 self.rendered_views.insert(view_id, tree);
355 }
356 }
357}
358
359impl<'a> Deref for PaintContext<'a> {
360 type Target = AppContext;
361
362 fn deref(&self) -> &Self::Target {
363 self.app
364 }
365}
366
367pub struct EventContext<'a> {
368 rendered_views: &'a mut HashMap<usize, ElementBox>,
369 dispatched_actions: Vec<DispatchDirective>,
370 pub font_cache: &'a FontCache,
371 pub text_layout_cache: &'a TextLayoutCache,
372 pub app: &'a mut MutableAppContext,
373 pub notify_count: usize,
374 view_stack: Vec<usize>,
375 invalidated_views: HashSet<usize>,
376}
377
378impl<'a> EventContext<'a> {
379 fn dispatch_event(&mut self, view_id: usize, event: &Event) -> bool {
380 if let Some(mut element) = self.rendered_views.remove(&view_id) {
381 self.view_stack.push(view_id);
382 let result = element.dispatch_event(event, self);
383 self.view_stack.pop();
384 self.rendered_views.insert(view_id, element);
385 result
386 } else {
387 false
388 }
389 }
390
391 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
392 self.dispatched_actions.push(DispatchDirective {
393 path: self.view_stack.clone(),
394 action,
395 });
396 }
397
398 pub fn dispatch_action<A: Action>(&mut self, action: A) {
399 self.dispatch_any_action(Box::new(action));
400 }
401
402 pub fn notify(&mut self) {
403 self.notify_count += 1;
404 if let Some(view_id) = self.view_stack.last() {
405 self.invalidated_views.insert(*view_id);
406 }
407 }
408
409 pub fn notify_count(&self) -> usize {
410 self.notify_count
411 }
412}
413
414impl<'a> Deref for EventContext<'a> {
415 type Target = MutableAppContext;
416
417 fn deref(&self) -> &Self::Target {
418 self.app
419 }
420}
421
422impl<'a> DerefMut for EventContext<'a> {
423 fn deref_mut(&mut self) -> &mut Self::Target {
424 self.app
425 }
426}
427
428pub struct DebugContext<'a> {
429 rendered_views: &'a HashMap<usize, ElementBox>,
430 pub font_cache: &'a FontCache,
431 pub app: &'a AppContext,
432}
433
434#[derive(Clone, Copy, Debug, Eq, PartialEq)]
435pub enum Axis {
436 Horizontal,
437 Vertical,
438}
439
440impl Axis {
441 pub fn invert(self) -> Self {
442 match self {
443 Self::Horizontal => Self::Vertical,
444 Self::Vertical => Self::Horizontal,
445 }
446 }
447}
448
449impl ToJson for Axis {
450 fn to_json(&self) -> serde_json::Value {
451 match self {
452 Axis::Horizontal => json!("horizontal"),
453 Axis::Vertical => json!("vertical"),
454 }
455 }
456}
457
458pub trait Vector2FExt {
459 fn along(self, axis: Axis) -> f32;
460}
461
462impl Vector2FExt for Vector2F {
463 fn along(self, axis: Axis) -> f32 {
464 match axis {
465 Axis::Horizontal => self.x(),
466 Axis::Vertical => self.y(),
467 }
468 }
469}
470
471#[derive(Copy, Clone, Debug)]
472pub struct SizeConstraint {
473 pub min: Vector2F,
474 pub max: Vector2F,
475}
476
477impl SizeConstraint {
478 pub fn new(min: Vector2F, max: Vector2F) -> Self {
479 Self { min, max }
480 }
481
482 pub fn strict(size: Vector2F) -> Self {
483 Self {
484 min: size,
485 max: size,
486 }
487 }
488
489 pub fn strict_along(axis: Axis, max: f32) -> Self {
490 match axis {
491 Axis::Horizontal => Self {
492 min: vec2f(max, 0.0),
493 max: vec2f(max, f32::INFINITY),
494 },
495 Axis::Vertical => Self {
496 min: vec2f(0.0, max),
497 max: vec2f(f32::INFINITY, max),
498 },
499 }
500 }
501
502 pub fn max_along(&self, axis: Axis) -> f32 {
503 match axis {
504 Axis::Horizontal => self.max.x(),
505 Axis::Vertical => self.max.y(),
506 }
507 }
508
509 pub fn min_along(&self, axis: Axis) -> f32 {
510 match axis {
511 Axis::Horizontal => self.min.x(),
512 Axis::Vertical => self.min.y(),
513 }
514 }
515
516 pub fn constrain(&self, size: Vector2F) -> Vector2F {
517 vec2f(
518 size.x().min(self.max.x()).max(self.min.x()),
519 size.y().min(self.max.y()).max(self.min.y()),
520 )
521 }
522}
523
524impl ToJson for SizeConstraint {
525 fn to_json(&self) -> serde_json::Value {
526 json!({
527 "min": self.min.to_json(),
528 "max": self.max.to_json(),
529 })
530 }
531}
532
533pub struct ChildView {
534 view: AnyViewHandle,
535}
536
537impl ChildView {
538 pub fn new(view: impl Into<AnyViewHandle>) -> Self {
539 Self { view: view.into() }
540 }
541}
542
543impl Element for ChildView {
544 type LayoutState = ();
545 type PaintState = ();
546
547 fn layout(
548 &mut self,
549 constraint: SizeConstraint,
550 cx: &mut LayoutContext,
551 ) -> (Vector2F, Self::LayoutState) {
552 let size = cx.layout(self.view.id(), constraint);
553 (size, ())
554 }
555
556 fn paint(
557 &mut self,
558 bounds: RectF,
559 visible_bounds: RectF,
560 _: &mut Self::LayoutState,
561 cx: &mut PaintContext,
562 ) -> Self::PaintState {
563 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
564 }
565
566 fn dispatch_event(
567 &mut self,
568 event: &Event,
569 _: RectF,
570 _: RectF,
571 _: &mut Self::LayoutState,
572 _: &mut Self::PaintState,
573 cx: &mut EventContext,
574 ) -> bool {
575 cx.dispatch_event(self.view.id(), event)
576 }
577
578 fn debug(
579 &self,
580 bounds: RectF,
581 _: &Self::LayoutState,
582 _: &Self::PaintState,
583 cx: &DebugContext,
584 ) -> serde_json::Value {
585 json!({
586 "type": "ChildView",
587 "view_id": self.view.id(),
588 "bounds": bounds.to_json(),
589 "view": self.view.debug_json(cx.app),
590 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
591 view.debug(cx)
592 } else {
593 json!(null)
594 }
595 })
596 }
597}