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 scene::{
9 CursorRegion, MouseClick, MouseDown, MouseDownOut, MouseDrag, MouseEvent, MouseHover,
10 MouseMove, MouseMoveOut, MouseScrollWheel, MouseUp, MouseUpOut, Scene,
11 },
12 text_layout::TextLayoutCache,
13 Action, AnyModelHandle, AnyViewHandle, AnyWeakModelHandle, AnyWeakViewHandle, Appearance,
14 AssetCache, ElementBox, Entity, FontSystem, ModelHandle, MouseButton, MouseMovedEvent,
15 MouseRegion, MouseRegionId, MouseState, ParentId, ReadModel, ReadView, RenderContext,
16 RenderParams, SceneBuilder, UpgradeModelHandle, UpgradeViewHandle, View, ViewHandle,
17 WeakModelHandle, WeakViewHandle,
18};
19use anyhow::bail;
20use collections::{HashMap, HashSet};
21use pathfinder_geometry::vector::{vec2f, Vector2F};
22use serde_json::json;
23use smallvec::SmallVec;
24use sqlez::{
25 bindable::{Bind, Column, StaticColumnCount},
26 statement::Statement,
27};
28use std::{
29 marker::PhantomData,
30 ops::{Deref, DerefMut, Range},
31 sync::Arc,
32};
33
34pub struct Presenter {
35 window_id: usize,
36 pub(crate) rendered_views: HashMap<usize, ElementBox>,
37 cursor_regions: Vec<CursorRegion>,
38 mouse_regions: Vec<(MouseRegion, usize)>,
39 font_cache: Arc<FontCache>,
40 text_layout_cache: TextLayoutCache,
41 asset_cache: Arc<AssetCache>,
42 last_mouse_moved_event: Option<Event>,
43 hovered_region_ids: HashSet<MouseRegionId>,
44 clicked_region_ids: HashSet<MouseRegionId>,
45 clicked_button: Option<MouseButton>,
46 mouse_position: Vector2F,
47 titlebar_height: f32,
48 appearance: Appearance,
49}
50
51impl Presenter {
52 pub fn new(
53 window_id: usize,
54 titlebar_height: f32,
55 appearance: Appearance,
56 font_cache: Arc<FontCache>,
57 text_layout_cache: TextLayoutCache,
58 asset_cache: Arc<AssetCache>,
59 cx: &mut MutableAppContext,
60 ) -> Self {
61 Self {
62 window_id,
63 rendered_views: cx.render_views(window_id, titlebar_height, appearance),
64 cursor_regions: Default::default(),
65 mouse_regions: Default::default(),
66 font_cache,
67 text_layout_cache,
68 asset_cache,
69 last_mouse_moved_event: None,
70 hovered_region_ids: Default::default(),
71 clicked_region_ids: Default::default(),
72 clicked_button: None,
73 mouse_position: vec2f(0., 0.),
74 titlebar_height,
75 appearance,
76 }
77 }
78
79 pub fn invalidate(
80 &mut self,
81 invalidation: &mut WindowInvalidation,
82 appearance: Appearance,
83 cx: &mut MutableAppContext,
84 ) {
85 cx.start_frame();
86 self.appearance = appearance;
87 for view_id in &invalidation.removed {
88 invalidation.updated.remove(view_id);
89 self.rendered_views.remove(view_id);
90 }
91 for view_id in &invalidation.updated {
92 self.rendered_views.insert(
93 *view_id,
94 cx.render_view(RenderParams {
95 window_id: self.window_id,
96 view_id: *view_id,
97 titlebar_height: self.titlebar_height,
98 hovered_region_ids: self.hovered_region_ids.clone(),
99 clicked_region_ids: self
100 .clicked_button
101 .map(|button| (self.clicked_region_ids.clone(), button)),
102 refreshing: false,
103 appearance,
104 })
105 .unwrap(),
106 );
107 }
108 }
109
110 pub fn refresh(
111 &mut self,
112 invalidation: &mut WindowInvalidation,
113 appearance: Appearance,
114 cx: &mut MutableAppContext,
115 ) {
116 self.invalidate(invalidation, appearance, cx);
117 for (view_id, view) in &mut self.rendered_views {
118 if !invalidation.updated.contains(view_id) {
119 *view = cx
120 .render_view(RenderParams {
121 window_id: self.window_id,
122 view_id: *view_id,
123 titlebar_height: self.titlebar_height,
124 hovered_region_ids: self.hovered_region_ids.clone(),
125 clicked_region_ids: self
126 .clicked_button
127 .map(|button| (self.clicked_region_ids.clone(), button)),
128 refreshing: true,
129 appearance,
130 })
131 .unwrap();
132 }
133 }
134 }
135
136 pub fn build_scene(
137 &mut self,
138 window_size: Vector2F,
139 scale_factor: f32,
140 refreshing: bool,
141 cx: &mut MutableAppContext,
142 ) -> Scene {
143 let mut scene_builder = SceneBuilder::new(scale_factor);
144
145 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
146 self.layout(window_size, refreshing, cx);
147 let mut paint_cx = self.build_paint_context(&mut scene_builder, window_size, cx);
148 paint_cx.paint(
149 root_view_id,
150 Vector2F::zero(),
151 RectF::new(Vector2F::zero(), window_size),
152 );
153 self.text_layout_cache.finish_frame();
154 let scene = scene_builder.build();
155 self.cursor_regions = scene.cursor_regions();
156 self.mouse_regions = scene.mouse_regions();
157
158 // window.is_topmost for the mouse moved event's postion?
159 if cx.window_is_active(self.window_id) {
160 if let Some(event) = self.last_mouse_moved_event.clone() {
161 self.dispatch_event(event, true, cx);
162 }
163 }
164
165 scene
166 } else {
167 log::error!("could not find root_view_id for window {}", self.window_id);
168 scene_builder.build()
169 }
170 }
171
172 fn layout(&mut self, window_size: Vector2F, refreshing: bool, cx: &mut MutableAppContext) {
173 if let Some(root_view_id) = cx.root_view_id(self.window_id) {
174 self.build_layout_context(window_size, refreshing, cx)
175 .layout(root_view_id, SizeConstraint::strict(window_size));
176 }
177 }
178
179 pub fn build_layout_context<'a>(
180 &'a mut self,
181 window_size: Vector2F,
182 refreshing: bool,
183 cx: &'a mut MutableAppContext,
184 ) -> LayoutContext<'a> {
185 LayoutContext {
186 window_id: self.window_id,
187 rendered_views: &mut self.rendered_views,
188 font_cache: &self.font_cache,
189 font_system: cx.platform().fonts(),
190 text_layout_cache: &self.text_layout_cache,
191 asset_cache: &self.asset_cache,
192 view_stack: Vec::new(),
193 refreshing,
194 hovered_region_ids: self.hovered_region_ids.clone(),
195 clicked_region_ids: self
196 .clicked_button
197 .map(|button| (self.clicked_region_ids.clone(), button)),
198 titlebar_height: self.titlebar_height,
199 appearance: self.appearance,
200 window_size,
201 app: cx,
202 }
203 }
204
205 pub fn build_paint_context<'a>(
206 &'a mut self,
207 scene: &'a mut SceneBuilder,
208 window_size: Vector2F,
209 cx: &'a mut MutableAppContext,
210 ) -> PaintContext {
211 PaintContext {
212 scene,
213 window_size,
214 font_cache: &self.font_cache,
215 text_layout_cache: &self.text_layout_cache,
216 rendered_views: &mut self.rendered_views,
217 view_stack: Vec::new(),
218 app: cx,
219 }
220 }
221
222 pub fn rect_for_text_range(&self, range_utf16: Range<usize>, cx: &AppContext) -> Option<RectF> {
223 cx.focused_view_id(self.window_id).and_then(|view_id| {
224 let cx = MeasurementContext {
225 app: cx,
226 rendered_views: &self.rendered_views,
227 window_id: self.window_id,
228 };
229 cx.rect_for_text_range(view_id, range_utf16)
230 })
231 }
232
233 pub fn dispatch_event(
234 &mut self,
235 event: Event,
236 event_reused: bool,
237 cx: &mut MutableAppContext,
238 ) -> bool {
239 let mut mouse_events = SmallVec::<[_; 2]>::new();
240 let mut notified_views: HashSet<usize> = Default::default();
241
242 // 1. Handle platform event. Keyboard events get dispatched immediately, while mouse events
243 // get mapped into the mouse-specific MouseEvent type.
244 // -> These are usually small: [Mouse Down] or [Mouse up, Click] or [Mouse Moved, Mouse Dragged?]
245 // -> Also updates mouse-related state
246 match &event {
247 Event::KeyDown(e) => return cx.dispatch_key_down(self.window_id, e),
248
249 Event::KeyUp(e) => return cx.dispatch_key_up(self.window_id, e),
250
251 Event::ModifiersChanged(e) => return cx.dispatch_modifiers_changed(self.window_id, e),
252
253 Event::MouseDown(e) => {
254 // Click events are weird because they can be fired after a drag event.
255 // MDN says that browsers handle this by starting from 'the most
256 // specific ancestor element that contained both [positions]'
257 // So we need to store the overlapping regions on mouse down.
258
259 // If there is already clicked_button stored, don't replace it.
260 if self.clicked_button.is_none() {
261 self.clicked_region_ids = self
262 .mouse_regions
263 .iter()
264 .filter_map(|(region, _)| {
265 if region.bounds.contains_point(e.position) {
266 Some(region.id())
267 } else {
268 None
269 }
270 })
271 .collect();
272
273 self.clicked_button = Some(e.button);
274 }
275
276 mouse_events.push(MouseEvent::Down(MouseDown {
277 region: Default::default(),
278 platform_event: e.clone(),
279 }));
280 mouse_events.push(MouseEvent::DownOut(MouseDownOut {
281 region: Default::default(),
282 platform_event: e.clone(),
283 }));
284 }
285
286 Event::MouseUp(e) => {
287 // NOTE: The order of event pushes is important! MouseUp events MUST be fired
288 // before click events, and so the MouseUp events need to be pushed before
289 // MouseClick events.
290 mouse_events.push(MouseEvent::Up(MouseUp {
291 region: Default::default(),
292 platform_event: e.clone(),
293 }));
294 mouse_events.push(MouseEvent::UpOut(MouseUpOut {
295 region: Default::default(),
296 platform_event: e.clone(),
297 }));
298 mouse_events.push(MouseEvent::Click(MouseClick {
299 region: Default::default(),
300 platform_event: e.clone(),
301 }));
302 }
303
304 Event::MouseMoved(
305 e @ MouseMovedEvent {
306 position,
307 pressed_button,
308 ..
309 },
310 ) => {
311 let mut style_to_assign = CursorStyle::Arrow;
312 for region in self.cursor_regions.iter().rev() {
313 if region.bounds.contains_point(*position) {
314 style_to_assign = region.style;
315 break;
316 }
317 }
318
319 if cx.is_topmost_window_for_position(self.window_id, *position) {
320 cx.platform().set_cursor_style(style_to_assign);
321 }
322
323 if !event_reused {
324 if pressed_button.is_some() {
325 mouse_events.push(MouseEvent::Drag(MouseDrag {
326 region: Default::default(),
327 prev_mouse_position: self.mouse_position,
328 platform_event: e.clone(),
329 }));
330 } else if let Some(clicked_button) = self.clicked_button {
331 // Mouse up event happened outside the current window. Simulate mouse up button event
332 let button_event = e.to_button_event(clicked_button);
333 mouse_events.push(MouseEvent::Up(MouseUp {
334 region: Default::default(),
335 platform_event: button_event.clone(),
336 }));
337 mouse_events.push(MouseEvent::UpOut(MouseUpOut {
338 region: Default::default(),
339 platform_event: button_event.clone(),
340 }));
341 mouse_events.push(MouseEvent::Click(MouseClick {
342 region: Default::default(),
343 platform_event: button_event.clone(),
344 }));
345 }
346
347 mouse_events.push(MouseEvent::Move(MouseMove {
348 region: Default::default(),
349 platform_event: e.clone(),
350 }));
351 }
352
353 mouse_events.push(MouseEvent::Hover(MouseHover {
354 region: Default::default(),
355 platform_event: e.clone(),
356 started: false,
357 }));
358 mouse_events.push(MouseEvent::MoveOut(MouseMoveOut {
359 region: Default::default(),
360 }));
361
362 self.last_mouse_moved_event = Some(event.clone());
363 }
364
365 Event::MouseExited(event) => {
366 // When the platform sends a MouseExited event, synthesize
367 // a MouseMoved event whose position is outside the window's
368 // bounds so that hover and cursor state can be updated.
369 return self.dispatch_event(
370 Event::MouseMoved(MouseMovedEvent {
371 position: event.position,
372 pressed_button: event.pressed_button,
373 modifiers: event.modifiers,
374 }),
375 event_reused,
376 cx,
377 );
378 }
379
380 Event::ScrollWheel(e) => mouse_events.push(MouseEvent::ScrollWheel(MouseScrollWheel {
381 region: Default::default(),
382 platform_event: e.clone(),
383 })),
384 }
385
386 if let Some(position) = event.position() {
387 self.mouse_position = position;
388 }
389
390 // 2. Dispatch mouse events on regions
391 let mut any_event_handled = false;
392 for mut mouse_event in mouse_events {
393 let mut valid_regions = Vec::new();
394
395 // GPUI elements are arranged by z_index but sibling elements can register overlapping
396 // mouse regions. As such, hover events are only fired on overlapping elements which
397 // are at the same z-index as the topmost element which overlaps with the mouse.
398 match &mouse_event {
399 MouseEvent::Hover(_) => {
400 let mut highest_z_index = None;
401 let mouse_position = self.mouse_position.clone();
402 for (region, z_index) in self.mouse_regions.iter().rev() {
403 // Allow mouse regions to appear transparent to hovers
404 if !region.hoverable {
405 continue;
406 }
407
408 let contains_mouse = region.bounds.contains_point(mouse_position);
409
410 if contains_mouse && highest_z_index.is_none() {
411 highest_z_index = Some(z_index);
412 }
413
414 // This unwrap relies on short circuiting boolean expressions
415 // The right side of the && is only executed when contains_mouse
416 // is true, and we know above that when contains_mouse is true
417 // highest_z_index is set.
418 if contains_mouse && z_index == highest_z_index.unwrap() {
419 //Ensure that hover entrance events aren't sent twice
420 if self.hovered_region_ids.insert(region.id()) {
421 valid_regions.push(region.clone());
422 if region.notify_on_hover {
423 notified_views.insert(region.id().view_id());
424 }
425 }
426 } else {
427 // Ensure that hover exit events aren't sent twice
428 if self.hovered_region_ids.remove(®ion.id()) {
429 valid_regions.push(region.clone());
430 if region.notify_on_hover {
431 notified_views.insert(region.id().view_id());
432 }
433 }
434 }
435 }
436 }
437
438 MouseEvent::Down(_) | MouseEvent::Up(_) => {
439 for (region, _) in self.mouse_regions.iter().rev() {
440 if region.bounds.contains_point(self.mouse_position) {
441 valid_regions.push(region.clone());
442 if region.notify_on_click {
443 notified_views.insert(region.id().view_id());
444 }
445 }
446 }
447 }
448
449 MouseEvent::Click(e) => {
450 // Only raise click events if the released button is the same as the one stored
451 if self
452 .clicked_button
453 .map(|clicked_button| clicked_button == e.button)
454 .unwrap_or(false)
455 {
456 // Clear clicked regions and clicked button
457 let clicked_region_ids =
458 std::mem::replace(&mut self.clicked_region_ids, Default::default());
459 self.clicked_button = None;
460
461 // Find regions which still overlap with the mouse since the last MouseDown happened
462 for (mouse_region, _) in self.mouse_regions.iter().rev() {
463 if clicked_region_ids.contains(&mouse_region.id()) {
464 if mouse_region.bounds.contains_point(self.mouse_position) {
465 valid_regions.push(mouse_region.clone());
466 }
467 }
468 }
469 }
470 }
471
472 MouseEvent::Drag(_) => {
473 for (mouse_region, _) in self.mouse_regions.iter().rev() {
474 if self.clicked_region_ids.contains(&mouse_region.id()) {
475 valid_regions.push(mouse_region.clone());
476 }
477 }
478 }
479
480 MouseEvent::MoveOut(_) | MouseEvent::UpOut(_) | MouseEvent::DownOut(_) => {
481 for (mouse_region, _) in self.mouse_regions.iter().rev() {
482 // NOT contains
483 if !mouse_region.bounds.contains_point(self.mouse_position) {
484 valid_regions.push(mouse_region.clone());
485 }
486 }
487 }
488
489 _ => {
490 for (mouse_region, _) in self.mouse_regions.iter().rev() {
491 // Contains
492 if mouse_region.bounds.contains_point(self.mouse_position) {
493 valid_regions.push(mouse_region.clone());
494 }
495 }
496 }
497 }
498
499 //3. Fire region events
500 let hovered_region_ids = self.hovered_region_ids.clone();
501 for valid_region in valid_regions.into_iter() {
502 let mut event_cx = self.build_event_context(&mut notified_views, cx);
503
504 mouse_event.set_region(valid_region.bounds);
505 if let MouseEvent::Hover(e) = &mut mouse_event {
506 e.started = hovered_region_ids.contains(&valid_region.id())
507 }
508 // Handle Down events if the MouseRegion has a Click or Drag handler. This makes the api more intuitive as you would
509 // not expect a MouseRegion to be transparent to Down events if it also has a Click handler.
510 // This behavior can be overridden by adding a Down handler
511 if let MouseEvent::Down(e) = &mouse_event {
512 let has_click = valid_region
513 .handlers
514 .contains(MouseEvent::click_disc(), Some(e.button));
515 let has_drag = valid_region
516 .handlers
517 .contains(MouseEvent::drag_disc(), Some(e.button));
518 let has_down = valid_region
519 .handlers
520 .contains(MouseEvent::down_disc(), Some(e.button));
521 if !has_down && (has_click || has_drag) {
522 event_cx.handled = true;
523 }
524 }
525
526 // `event_consumed` should only be true if there are any handlers for this event.
527 let mut event_consumed = event_cx.handled;
528 if let Some(callbacks) = valid_region.handlers.get(&mouse_event.handler_key()) {
529 for callback in callbacks {
530 event_cx.handled = true;
531 event_cx.with_current_view(valid_region.id().view_id(), {
532 let region_event = mouse_event.clone();
533 |cx| callback(region_event, cx)
534 });
535 event_consumed |= event_cx.handled;
536 any_event_handled |= event_cx.handled;
537 }
538 }
539
540 any_event_handled |= event_cx.handled;
541
542 // For bubbling events, if the event was handled, don't continue dispatching.
543 // This only makes sense for local events which return false from is_capturable.
544 if event_consumed && mouse_event.is_capturable() {
545 break;
546 }
547 }
548 }
549
550 for view_id in notified_views {
551 cx.notify_view(self.window_id, view_id);
552 }
553
554 any_event_handled
555 }
556
557 pub fn build_event_context<'a>(
558 &'a mut self,
559 notified_views: &'a mut HashSet<usize>,
560 cx: &'a mut MutableAppContext,
561 ) -> EventContext<'a> {
562 EventContext {
563 font_cache: &self.font_cache,
564 text_layout_cache: &self.text_layout_cache,
565 view_stack: Default::default(),
566 notified_views,
567 notify_count: 0,
568 handled: false,
569 window_id: self.window_id,
570 app: cx,
571 }
572 }
573
574 pub fn debug_elements(&self, cx: &AppContext) -> Option<json::Value> {
575 let view = cx.root_view(self.window_id)?;
576 Some(json!({
577 "root_view": view.debug_json(cx),
578 "root_element": self.rendered_views.get(&view.id())
579 .map(|root_element| {
580 root_element.debug(&DebugContext {
581 rendered_views: &self.rendered_views,
582 font_cache: &self.font_cache,
583 app: cx,
584 })
585 })
586 }))
587 }
588}
589
590pub struct LayoutContext<'a> {
591 window_id: usize,
592 rendered_views: &'a mut HashMap<usize, ElementBox>,
593 view_stack: Vec<usize>,
594 pub font_cache: &'a Arc<FontCache>,
595 pub font_system: Arc<dyn FontSystem>,
596 pub text_layout_cache: &'a TextLayoutCache,
597 pub asset_cache: &'a AssetCache,
598 pub app: &'a mut MutableAppContext,
599 pub refreshing: bool,
600 pub window_size: Vector2F,
601 titlebar_height: f32,
602 appearance: Appearance,
603 hovered_region_ids: HashSet<MouseRegionId>,
604 clicked_region_ids: Option<(HashSet<MouseRegionId>, MouseButton)>,
605}
606
607impl<'a> LayoutContext<'a> {
608 pub fn mouse_state<Tag: 'static>(&self, region_id: usize) -> MouseState {
609 let view_id = self.view_stack.last().unwrap();
610
611 let region_id = MouseRegionId::new::<Tag>(*view_id, region_id);
612 MouseState {
613 hovered: self.hovered_region_ids.contains(®ion_id),
614 clicked: self.clicked_region_ids.as_ref().and_then(|(ids, button)| {
615 if ids.contains(®ion_id) {
616 Some(*button)
617 } else {
618 None
619 }
620 }),
621 accessed_hovered: false,
622 accessed_clicked: false,
623 }
624 }
625
626 fn layout(&mut self, view_id: usize, constraint: SizeConstraint) -> Vector2F {
627 let print_error = |view_id| {
628 format!(
629 "{} with id {}",
630 self.app.name_for_view(self.window_id, view_id).unwrap(),
631 view_id,
632 )
633 };
634 match (
635 self.view_stack.last(),
636 self.app.parents.get(&(self.window_id, view_id)),
637 ) {
638 (Some(layout_parent), Some(ParentId::View(app_parent))) => {
639 if layout_parent != app_parent {
640 panic!(
641 "View {} was laid out with parent {} when it was constructed with parent {}",
642 print_error(view_id),
643 print_error(*layout_parent),
644 print_error(*app_parent))
645 }
646 }
647 (None, Some(ParentId::View(app_parent))) => panic!(
648 "View {} was laid out without a parent when it was constructed with parent {}",
649 print_error(view_id),
650 print_error(*app_parent)
651 ),
652 (Some(layout_parent), Some(ParentId::Root)) => panic!(
653 "View {} was laid out with parent {} when it was constructed as a window root",
654 print_error(view_id),
655 print_error(*layout_parent),
656 ),
657 (_, None) => panic!(
658 "View {} did not have a registered parent in the app context",
659 print_error(view_id),
660 ),
661 _ => {}
662 }
663
664 self.view_stack.push(view_id);
665 let mut rendered_view = self.rendered_views.remove(&view_id).unwrap();
666 let size = rendered_view.layout(constraint, self);
667 self.rendered_views.insert(view_id, rendered_view);
668 self.view_stack.pop();
669 size
670 }
671
672 pub fn render<F, V, T>(&mut self, handle: &ViewHandle<V>, f: F) -> T
673 where
674 F: FnOnce(&mut V, &mut RenderContext<V>) -> T,
675 V: View,
676 {
677 handle.update(self.app, |view, cx| {
678 let mut render_cx = RenderContext {
679 app: cx,
680 window_id: handle.window_id(),
681 view_id: handle.id(),
682 view_type: PhantomData,
683 titlebar_height: self.titlebar_height,
684 hovered_region_ids: self.hovered_region_ids.clone(),
685 clicked_region_ids: self.clicked_region_ids.clone(),
686 refreshing: self.refreshing,
687 appearance: self.appearance,
688 };
689 f(view, &mut render_cx)
690 })
691 }
692}
693
694impl<'a> Deref for LayoutContext<'a> {
695 type Target = MutableAppContext;
696
697 fn deref(&self) -> &Self::Target {
698 self.app
699 }
700}
701
702impl<'a> DerefMut for LayoutContext<'a> {
703 fn deref_mut(&mut self) -> &mut Self::Target {
704 self.app
705 }
706}
707
708impl<'a> ReadView for LayoutContext<'a> {
709 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
710 self.app.read_view(handle)
711 }
712}
713
714impl<'a> ReadModel for LayoutContext<'a> {
715 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
716 self.app.read_model(handle)
717 }
718}
719
720impl<'a> UpgradeModelHandle for LayoutContext<'a> {
721 fn upgrade_model_handle<T: Entity>(
722 &self,
723 handle: &WeakModelHandle<T>,
724 ) -> Option<ModelHandle<T>> {
725 self.app.upgrade_model_handle(handle)
726 }
727
728 fn model_handle_is_upgradable<T: Entity>(&self, handle: &WeakModelHandle<T>) -> bool {
729 self.app.model_handle_is_upgradable(handle)
730 }
731
732 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
733 self.app.upgrade_any_model_handle(handle)
734 }
735}
736
737impl<'a> UpgradeViewHandle for LayoutContext<'a> {
738 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
739 self.app.upgrade_view_handle(handle)
740 }
741
742 fn upgrade_any_view_handle(&self, handle: &crate::AnyWeakViewHandle) -> Option<AnyViewHandle> {
743 self.app.upgrade_any_view_handle(handle)
744 }
745}
746
747pub struct PaintContext<'a> {
748 rendered_views: &'a mut HashMap<usize, ElementBox>,
749 view_stack: Vec<usize>,
750 pub window_size: Vector2F,
751 pub scene: &'a mut SceneBuilder,
752 pub font_cache: &'a FontCache,
753 pub text_layout_cache: &'a TextLayoutCache,
754 pub app: &'a AppContext,
755}
756
757impl<'a> PaintContext<'a> {
758 fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
759 if let Some(mut tree) = self.rendered_views.remove(&view_id) {
760 self.view_stack.push(view_id);
761 tree.paint(origin, visible_bounds, self);
762 self.rendered_views.insert(view_id, tree);
763 self.view_stack.pop();
764 }
765 }
766
767 #[inline]
768 pub fn paint_stacking_context<F>(
769 &mut self,
770 clip_bounds: Option<RectF>,
771 z_index: Option<usize>,
772 f: F,
773 ) where
774 F: FnOnce(&mut Self),
775 {
776 self.scene.push_stacking_context(clip_bounds, z_index);
777 f(self);
778 self.scene.pop_stacking_context();
779 }
780
781 #[inline]
782 pub fn paint_layer<F>(&mut self, clip_bounds: Option<RectF>, f: F)
783 where
784 F: FnOnce(&mut Self),
785 {
786 self.scene.push_layer(clip_bounds);
787 f(self);
788 self.scene.pop_layer();
789 }
790
791 pub fn current_view_id(&self) -> usize {
792 *self.view_stack.last().unwrap()
793 }
794}
795
796impl<'a> Deref for PaintContext<'a> {
797 type Target = AppContext;
798
799 fn deref(&self) -> &Self::Target {
800 self.app
801 }
802}
803
804pub struct EventContext<'a> {
805 pub font_cache: &'a FontCache,
806 pub text_layout_cache: &'a TextLayoutCache,
807 pub app: &'a mut MutableAppContext,
808 pub window_id: usize,
809 pub notify_count: usize,
810 view_stack: Vec<usize>,
811 handled: bool,
812 notified_views: &'a mut HashSet<usize>,
813}
814
815impl<'a> EventContext<'a> {
816 fn with_current_view<F, T>(&mut self, view_id: usize, f: F) -> T
817 where
818 F: FnOnce(&mut Self) -> T,
819 {
820 self.view_stack.push(view_id);
821 let result = f(self);
822 self.view_stack.pop();
823 result
824 }
825
826 pub fn window_id(&self) -> usize {
827 self.window_id
828 }
829
830 pub fn view_id(&self) -> Option<usize> {
831 self.view_stack.last().copied()
832 }
833
834 pub fn is_parent_view_focused(&self) -> bool {
835 if let Some(parent_view_id) = self.view_stack.last() {
836 self.app.focused_view_id(self.window_id) == Some(*parent_view_id)
837 } else {
838 false
839 }
840 }
841
842 pub fn focus_parent_view(&mut self) {
843 if let Some(parent_view_id) = self.view_stack.last() {
844 self.app.focus(self.window_id, Some(*parent_view_id))
845 }
846 }
847
848 pub fn dispatch_any_action(&mut self, action: Box<dyn Action>) {
849 self.app
850 .dispatch_any_action_at(self.window_id, *self.view_stack.last().unwrap(), action)
851 }
852
853 pub fn dispatch_action<A: Action>(&mut self, action: A) {
854 self.dispatch_any_action(Box::new(action));
855 }
856
857 pub fn notify(&mut self) {
858 self.notify_count += 1;
859 if let Some(view_id) = self.view_stack.last() {
860 self.notified_views.insert(*view_id);
861 }
862 }
863
864 pub fn notify_count(&self) -> usize {
865 self.notify_count
866 }
867
868 pub fn propagate_event(&mut self) {
869 self.handled = false;
870 }
871}
872
873impl<'a> Deref for EventContext<'a> {
874 type Target = MutableAppContext;
875
876 fn deref(&self) -> &Self::Target {
877 self.app
878 }
879}
880
881impl<'a> DerefMut for EventContext<'a> {
882 fn deref_mut(&mut self) -> &mut Self::Target {
883 self.app
884 }
885}
886
887pub struct MeasurementContext<'a> {
888 app: &'a AppContext,
889 rendered_views: &'a HashMap<usize, ElementBox>,
890 pub window_id: usize,
891}
892
893impl<'a> Deref for MeasurementContext<'a> {
894 type Target = AppContext;
895
896 fn deref(&self) -> &Self::Target {
897 self.app
898 }
899}
900
901impl<'a> MeasurementContext<'a> {
902 fn rect_for_text_range(&self, view_id: usize, range_utf16: Range<usize>) -> Option<RectF> {
903 let element = self.rendered_views.get(&view_id)?;
904 element.rect_for_text_range(range_utf16, self)
905 }
906}
907
908pub struct DebugContext<'a> {
909 rendered_views: &'a HashMap<usize, ElementBox>,
910 pub font_cache: &'a FontCache,
911 pub app: &'a AppContext,
912}
913
914#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
915pub enum Axis {
916 #[default]
917 Horizontal,
918 Vertical,
919}
920
921impl Axis {
922 pub fn invert(self) -> Self {
923 match self {
924 Self::Horizontal => Self::Vertical,
925 Self::Vertical => Self::Horizontal,
926 }
927 }
928
929 pub fn component(&self, point: Vector2F) -> f32 {
930 match self {
931 Self::Horizontal => point.x(),
932 Self::Vertical => point.y(),
933 }
934 }
935}
936
937impl ToJson for Axis {
938 fn to_json(&self) -> serde_json::Value {
939 match self {
940 Axis::Horizontal => json!("horizontal"),
941 Axis::Vertical => json!("vertical"),
942 }
943 }
944}
945
946impl StaticColumnCount for Axis {}
947impl Bind for Axis {
948 fn bind(&self, statement: &Statement, start_index: i32) -> anyhow::Result<i32> {
949 match self {
950 Axis::Horizontal => "Horizontal",
951 Axis::Vertical => "Vertical",
952 }
953 .bind(statement, start_index)
954 }
955}
956
957impl Column for Axis {
958 fn column(statement: &mut Statement, start_index: i32) -> anyhow::Result<(Self, i32)> {
959 String::column(statement, start_index).and_then(|(axis_text, next_index)| {
960 Ok((
961 match axis_text.as_str() {
962 "Horizontal" => Axis::Horizontal,
963 "Vertical" => Axis::Vertical,
964 _ => bail!("Stored serialized item kind is incorrect"),
965 },
966 next_index,
967 ))
968 })
969 }
970}
971
972pub trait Vector2FExt {
973 fn along(self, axis: Axis) -> f32;
974}
975
976impl Vector2FExt for Vector2F {
977 fn along(self, axis: Axis) -> f32 {
978 match axis {
979 Axis::Horizontal => self.x(),
980 Axis::Vertical => self.y(),
981 }
982 }
983}
984
985#[derive(Copy, Clone, Debug)]
986pub struct SizeConstraint {
987 pub min: Vector2F,
988 pub max: Vector2F,
989}
990
991impl SizeConstraint {
992 pub fn new(min: Vector2F, max: Vector2F) -> Self {
993 Self { min, max }
994 }
995
996 pub fn strict(size: Vector2F) -> Self {
997 Self {
998 min: size,
999 max: size,
1000 }
1001 }
1002
1003 pub fn strict_along(axis: Axis, max: f32) -> Self {
1004 match axis {
1005 Axis::Horizontal => Self {
1006 min: vec2f(max, 0.0),
1007 max: vec2f(max, f32::INFINITY),
1008 },
1009 Axis::Vertical => Self {
1010 min: vec2f(0.0, max),
1011 max: vec2f(f32::INFINITY, max),
1012 },
1013 }
1014 }
1015
1016 pub fn max_along(&self, axis: Axis) -> f32 {
1017 match axis {
1018 Axis::Horizontal => self.max.x(),
1019 Axis::Vertical => self.max.y(),
1020 }
1021 }
1022
1023 pub fn min_along(&self, axis: Axis) -> f32 {
1024 match axis {
1025 Axis::Horizontal => self.min.x(),
1026 Axis::Vertical => self.min.y(),
1027 }
1028 }
1029
1030 pub fn constrain(&self, size: Vector2F) -> Vector2F {
1031 vec2f(
1032 size.x().min(self.max.x()).max(self.min.x()),
1033 size.y().min(self.max.y()).max(self.min.y()),
1034 )
1035 }
1036}
1037
1038impl Default for SizeConstraint {
1039 fn default() -> Self {
1040 SizeConstraint {
1041 min: Vector2F::zero(),
1042 max: Vector2F::splat(f32::INFINITY),
1043 }
1044 }
1045}
1046
1047impl ToJson for SizeConstraint {
1048 fn to_json(&self) -> serde_json::Value {
1049 json!({
1050 "min": self.min.to_json(),
1051 "max": self.max.to_json(),
1052 })
1053 }
1054}
1055
1056pub struct ChildView {
1057 view: AnyWeakViewHandle,
1058 view_name: &'static str,
1059}
1060
1061impl ChildView {
1062 pub fn new(view: &AnyViewHandle, cx: &AppContext) -> Self {
1063 let view_name = cx.view_ui_name(view.window_id(), view.id()).unwrap();
1064 Self {
1065 view: view.downgrade(),
1066 view_name,
1067 }
1068 }
1069}
1070
1071impl Element for ChildView {
1072 type LayoutState = bool;
1073 type PaintState = ();
1074
1075 fn layout(
1076 &mut self,
1077 constraint: SizeConstraint,
1078 cx: &mut LayoutContext,
1079 ) -> (Vector2F, Self::LayoutState) {
1080 if cx.rendered_views.contains_key(&self.view.id()) {
1081 let size = cx.layout(self.view.id(), constraint);
1082 (size, true)
1083 } else {
1084 log::error!(
1085 "layout called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1086 self.view.id(),
1087 self.view_name
1088 );
1089 (Vector2F::zero(), false)
1090 }
1091 }
1092
1093 fn paint(
1094 &mut self,
1095 bounds: RectF,
1096 visible_bounds: RectF,
1097 view_is_valid: &mut Self::LayoutState,
1098 cx: &mut PaintContext,
1099 ) {
1100 if *view_is_valid {
1101 cx.paint(self.view.id(), bounds.origin(), visible_bounds);
1102 } else {
1103 log::error!(
1104 "paint called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1105 self.view.id(),
1106 self.view_name
1107 );
1108 }
1109 }
1110
1111 fn rect_for_text_range(
1112 &self,
1113 range_utf16: Range<usize>,
1114 _: RectF,
1115 _: RectF,
1116 view_is_valid: &Self::LayoutState,
1117 _: &Self::PaintState,
1118 cx: &MeasurementContext,
1119 ) -> Option<RectF> {
1120 if *view_is_valid {
1121 cx.rect_for_text_range(self.view.id(), range_utf16)
1122 } else {
1123 log::error!(
1124 "rect_for_text_range called on a ChildView element whose underlying view was dropped (view_id: {}, name: {:?})",
1125 self.view.id(),
1126 self.view_name
1127 );
1128 None
1129 }
1130 }
1131
1132 fn debug(
1133 &self,
1134 bounds: RectF,
1135 _: &Self::LayoutState,
1136 _: &Self::PaintState,
1137 cx: &DebugContext,
1138 ) -> serde_json::Value {
1139 json!({
1140 "type": "ChildView",
1141 "view_id": self.view.id(),
1142 "bounds": bounds.to_json(),
1143 "view": if let Some(view) = self.view.upgrade(cx.app) {
1144 view.debug_json(cx.app)
1145 } else {
1146 json!(null)
1147 },
1148 "child": if let Some(view) = cx.rendered_views.get(&self.view.id()) {
1149 view.debug(cx)
1150 } else {
1151 json!(null)
1152 }
1153 })
1154 }
1155}