1//! The element context is the main interface for interacting with the frame during a paint.
2//!
3//! Elements are hierarchical and with a few exceptions the context accumulates state in a stack
4//! as it processes all of the elements in the frame. The methods that interact with this stack
5//! are generally marked with `with_*`, and take a callback to denote the region of code that
6//! should be executed with that state.
7//!
8//! The other main interface is the `paint_*` family of methods, which push basic drawing commands
9//! to the GPU. Everything in a GPUI app is drawn with these methods.
10//!
11//! There are also several internal methods that GPUI uses, such as [`ElementContext::with_element_state`]
12//! to call the paint and layout methods on elements. These have been included as they're often useful
13//! for taking manual control of the layouting or painting of specialized elements.
14
15use std::{
16 any::{Any, TypeId},
17 borrow::{Borrow, BorrowMut, Cow},
18 mem,
19 rc::Rc,
20 sync::Arc,
21};
22
23use anyhow::Result;
24use collections::{FxHashMap, FxHashSet};
25use derive_more::{Deref, DerefMut};
26use media::core_video::CVImageBuffer;
27use smallvec::SmallVec;
28use util::post_inc;
29
30use crate::{
31 prelude::*, size, AnyTooltip, AppContext, AvailableSpace, Bounds, BoxShadow, ContentMask,
32 Corners, CursorStyle, DevicePixels, DispatchPhase, DispatchTree, ElementId, ElementStateBox,
33 EntityId, FocusHandle, FocusId, FontId, GlobalElementId, GlyphId, Hsla, ImageData,
34 InputHandler, IsZero, KeyContext, KeyEvent, KeymatchMode, LayoutId, MonochromeSprite,
35 MouseEvent, PaintQuad, Path, Pixels, PlatformInputHandler, Point, PolychromeSprite, Quad,
36 RenderGlyphParams, RenderImageParams, RenderSvgParams, Scene, Shadow, SharedString, Size,
37 StackingContext, StackingOrder, Style, Surface, TextStyleRefinement, Underline, UnderlineStyle,
38 Window, WindowContext, SUBPIXEL_VARIANTS,
39};
40
41type AnyMouseListener = Box<dyn FnMut(&dyn Any, DispatchPhase, &mut ElementContext) + 'static>;
42
43pub(crate) struct RequestedInputHandler {
44 pub(crate) view_id: EntityId,
45 pub(crate) handler: Option<PlatformInputHandler>,
46}
47
48pub(crate) struct TooltipRequest {
49 pub(crate) view_id: EntityId,
50 pub(crate) tooltip: AnyTooltip,
51}
52
53pub(crate) struct Frame {
54 pub(crate) focus: Option<FocusId>,
55 pub(crate) window_active: bool,
56 pub(crate) element_states: FxHashMap<GlobalElementId, ElementStateBox>,
57 pub(crate) mouse_listeners: FxHashMap<TypeId, Vec<(StackingOrder, EntityId, AnyMouseListener)>>,
58 pub(crate) dispatch_tree: DispatchTree,
59 pub(crate) scene: Scene,
60 pub(crate) depth_map: Vec<(StackingOrder, EntityId, Bounds<Pixels>)>,
61 pub(crate) z_index_stack: StackingOrder,
62 pub(crate) next_stacking_order_id: u16,
63 pub(crate) next_root_z_index: u16,
64 pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
65 pub(crate) element_offset_stack: Vec<Point<Pixels>>,
66 pub(crate) requested_input_handler: Option<RequestedInputHandler>,
67 pub(crate) tooltip_request: Option<TooltipRequest>,
68 pub(crate) cursor_styles: FxHashMap<EntityId, CursorStyle>,
69 pub(crate) requested_cursor_style: Option<CursorStyle>,
70 pub(crate) view_stack: Vec<EntityId>,
71 pub(crate) reused_views: FxHashSet<EntityId>,
72
73 #[cfg(any(test, feature = "test-support"))]
74 pub(crate) debug_bounds: collections::FxHashMap<String, Bounds<Pixels>>,
75}
76
77impl Frame {
78 pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
79 Frame {
80 focus: None,
81 window_active: false,
82 element_states: FxHashMap::default(),
83 mouse_listeners: FxHashMap::default(),
84 dispatch_tree,
85 scene: Scene::default(),
86 depth_map: Vec::new(),
87 z_index_stack: StackingOrder::default(),
88 next_stacking_order_id: 0,
89 next_root_z_index: 0,
90 content_mask_stack: Vec::new(),
91 element_offset_stack: Vec::new(),
92 requested_input_handler: None,
93 tooltip_request: None,
94 cursor_styles: FxHashMap::default(),
95 requested_cursor_style: None,
96 view_stack: Vec::new(),
97 reused_views: FxHashSet::default(),
98
99 #[cfg(any(test, feature = "test-support"))]
100 debug_bounds: FxHashMap::default(),
101 }
102 }
103
104 pub(crate) fn clear(&mut self) {
105 self.element_states.clear();
106 self.mouse_listeners.values_mut().for_each(Vec::clear);
107 self.dispatch_tree.clear();
108 self.depth_map.clear();
109 self.next_stacking_order_id = 0;
110 self.next_root_z_index = 0;
111 self.reused_views.clear();
112 self.scene.clear();
113 self.requested_input_handler.take();
114 self.tooltip_request.take();
115 self.cursor_styles.clear();
116 self.requested_cursor_style.take();
117 debug_assert_eq!(self.view_stack.len(), 0);
118 }
119
120 pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
121 self.focus
122 .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
123 .unwrap_or_default()
124 }
125
126 pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
127 // Reuse mouse listeners that didn't change since the last frame.
128 for (type_id, listeners) in &mut prev_frame.mouse_listeners {
129 let next_listeners = self.mouse_listeners.entry(*type_id).or_default();
130 for (order, view_id, listener) in listeners.drain(..) {
131 if self.reused_views.contains(&view_id) {
132 next_listeners.push((order, view_id, listener));
133 }
134 }
135 }
136
137 // Reuse entries in the depth map that didn't change since the last frame.
138 for (order, view_id, bounds) in prev_frame.depth_map.drain(..) {
139 if self.reused_views.contains(&view_id) {
140 match self
141 .depth_map
142 .binary_search_by(|(level, _, _)| order.cmp(level))
143 {
144 Ok(i) | Err(i) => self.depth_map.insert(i, (order, view_id, bounds)),
145 }
146 }
147 }
148
149 // Retain element states for views that didn't change since the last frame.
150 for (element_id, state) in prev_frame.element_states.drain() {
151 if self.reused_views.contains(&state.parent_view_id) {
152 self.element_states.entry(element_id).or_insert(state);
153 }
154 }
155
156 // Reuse geometry that didn't change since the last frame.
157 self.scene
158 .reuse_views(&self.reused_views, &mut prev_frame.scene);
159 self.scene.finish();
160 }
161}
162
163/// This context is used for assisting in the implementation of the element trait
164#[derive(Deref, DerefMut)]
165pub struct ElementContext<'a> {
166 pub(crate) cx: WindowContext<'a>,
167}
168
169impl<'a> WindowContext<'a> {
170 /// Convert this window context into an ElementContext in this callback.
171 /// If you need to use this method, you're probably intermixing the imperative
172 /// and declarative APIs, which is not recommended.
173 pub fn with_element_context<R>(&mut self, f: impl FnOnce(&mut ElementContext) -> R) -> R {
174 f(&mut ElementContext {
175 cx: WindowContext::new(self.app, self.window),
176 })
177 }
178}
179
180impl<'a> Borrow<AppContext> for ElementContext<'a> {
181 fn borrow(&self) -> &AppContext {
182 self.cx.app
183 }
184}
185
186impl<'a> BorrowMut<AppContext> for ElementContext<'a> {
187 fn borrow_mut(&mut self) -> &mut AppContext {
188 self.cx.borrow_mut()
189 }
190}
191
192impl<'a> Borrow<WindowContext<'a>> for ElementContext<'a> {
193 fn borrow(&self) -> &WindowContext<'a> {
194 &self.cx
195 }
196}
197
198impl<'a> BorrowMut<WindowContext<'a>> for ElementContext<'a> {
199 fn borrow_mut(&mut self) -> &mut WindowContext<'a> {
200 &mut self.cx
201 }
202}
203
204impl<'a> Borrow<Window> for ElementContext<'a> {
205 fn borrow(&self) -> &Window {
206 self.cx.window
207 }
208}
209
210impl<'a> BorrowMut<Window> for ElementContext<'a> {
211 fn borrow_mut(&mut self) -> &mut Window {
212 self.cx.borrow_mut()
213 }
214}
215
216impl<'a> Context for ElementContext<'a> {
217 type Result<T> = <WindowContext<'a> as Context>::Result<T>;
218
219 fn new_model<T: 'static>(
220 &mut self,
221 build_model: impl FnOnce(&mut crate::ModelContext<'_, T>) -> T,
222 ) -> Self::Result<crate::Model<T>> {
223 self.cx.new_model(build_model)
224 }
225
226 fn update_model<T, R>(
227 &mut self,
228 handle: &crate::Model<T>,
229 update: impl FnOnce(&mut T, &mut crate::ModelContext<'_, T>) -> R,
230 ) -> Self::Result<R>
231 where
232 T: 'static,
233 {
234 self.cx.update_model(handle, update)
235 }
236
237 fn read_model<T, R>(
238 &self,
239 handle: &crate::Model<T>,
240 read: impl FnOnce(&T, &AppContext) -> R,
241 ) -> Self::Result<R>
242 where
243 T: 'static,
244 {
245 self.cx.read_model(handle, read)
246 }
247
248 fn update_window<T, F>(&mut self, window: crate::AnyWindowHandle, f: F) -> Result<T>
249 where
250 F: FnOnce(crate::AnyView, &mut WindowContext<'_>) -> T,
251 {
252 self.cx.update_window(window, f)
253 }
254
255 fn read_window<T, R>(
256 &self,
257 window: &crate::WindowHandle<T>,
258 read: impl FnOnce(crate::View<T>, &AppContext) -> R,
259 ) -> Result<R>
260 where
261 T: 'static,
262 {
263 self.cx.read_window(window, read)
264 }
265}
266
267impl<'a> VisualContext for ElementContext<'a> {
268 fn new_view<V>(
269 &mut self,
270 build_view: impl FnOnce(&mut crate::ViewContext<'_, V>) -> V,
271 ) -> Self::Result<crate::View<V>>
272 where
273 V: 'static + Render,
274 {
275 self.cx.new_view(build_view)
276 }
277
278 fn update_view<V: 'static, R>(
279 &mut self,
280 view: &crate::View<V>,
281 update: impl FnOnce(&mut V, &mut crate::ViewContext<'_, V>) -> R,
282 ) -> Self::Result<R> {
283 self.cx.update_view(view, update)
284 }
285
286 fn replace_root_view<V>(
287 &mut self,
288 build_view: impl FnOnce(&mut crate::ViewContext<'_, V>) -> V,
289 ) -> Self::Result<crate::View<V>>
290 where
291 V: 'static + Render,
292 {
293 self.cx.replace_root_view(build_view)
294 }
295
296 fn focus_view<V>(&mut self, view: &crate::View<V>) -> Self::Result<()>
297 where
298 V: crate::FocusableView,
299 {
300 self.cx.focus_view(view)
301 }
302
303 fn dismiss_view<V>(&mut self, view: &crate::View<V>) -> Self::Result<()>
304 where
305 V: crate::ManagedView,
306 {
307 self.cx.dismiss_view(view)
308 }
309}
310
311impl<'a> ElementContext<'a> {
312 pub(crate) fn reuse_view(&mut self, next_stacking_order_id: u16) {
313 let view_id = self.parent_view_id();
314 let grafted_view_ids = self
315 .cx
316 .window
317 .next_frame
318 .dispatch_tree
319 .reuse_view(view_id, &mut self.cx.window.rendered_frame.dispatch_tree);
320 for view_id in grafted_view_ids {
321 assert!(self.window.next_frame.reused_views.insert(view_id));
322
323 // Reuse the previous input handler requested during painting of the reused view.
324 if self
325 .window
326 .rendered_frame
327 .requested_input_handler
328 .as_ref()
329 .map_or(false, |requested| requested.view_id == view_id)
330 {
331 self.window.next_frame.requested_input_handler =
332 self.window.rendered_frame.requested_input_handler.take();
333 }
334
335 // Reuse the tooltip previously requested during painting of the reused view.
336 if self
337 .window
338 .rendered_frame
339 .tooltip_request
340 .as_ref()
341 .map_or(false, |requested| requested.view_id == view_id)
342 {
343 self.window.next_frame.tooltip_request =
344 self.window.rendered_frame.tooltip_request.take();
345 }
346
347 // Reuse the cursor styles previously requested during painting of the reused view.
348 if let Some(style) = self.window.rendered_frame.cursor_styles.remove(&view_id) {
349 self.window.next_frame.cursor_styles.insert(view_id, style);
350 self.window.next_frame.requested_cursor_style = Some(style);
351 }
352 }
353
354 debug_assert!(next_stacking_order_id >= self.window.next_frame.next_stacking_order_id);
355 self.window.next_frame.next_stacking_order_id = next_stacking_order_id;
356 }
357
358 /// Push a text style onto the stack, and call a function with that style active.
359 /// Use [`AppContext::text_style`] to get the current, combined text style.
360 pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
361 where
362 F: FnOnce(&mut Self) -> R,
363 {
364 if let Some(style) = style {
365 self.push_text_style(style);
366 let result = f(self);
367 self.pop_text_style();
368 result
369 } else {
370 f(self)
371 }
372 }
373
374 /// Updates the cursor style at the platform level.
375 pub fn set_cursor_style(&mut self, style: CursorStyle) {
376 let view_id = self.parent_view_id();
377 self.window.next_frame.cursor_styles.insert(view_id, style);
378 self.window.next_frame.requested_cursor_style = Some(style);
379 }
380
381 /// Sets a tooltip to be rendered for the upcoming frame
382 pub fn set_tooltip(&mut self, tooltip: AnyTooltip) {
383 let view_id = self.parent_view_id();
384 self.window.next_frame.tooltip_request = Some(TooltipRequest { view_id, tooltip });
385 }
386
387 /// Pushes the given element id onto the global stack and invokes the given closure
388 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
389 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
390 /// used to associate state with identified elements across separate frames.
391 pub fn with_element_id<R>(
392 &mut self,
393 id: Option<impl Into<ElementId>>,
394 f: impl FnOnce(&mut Self) -> R,
395 ) -> R {
396 if let Some(id) = id.map(Into::into) {
397 let window = self.window_mut();
398 window.element_id_stack.push(id);
399 let result = f(self);
400 let window: &mut Window = self.borrow_mut();
401 window.element_id_stack.pop();
402 result
403 } else {
404 f(self)
405 }
406 }
407
408 /// Invoke the given function with the given content mask after intersecting it
409 /// with the current mask.
410 pub fn with_content_mask<R>(
411 &mut self,
412 mask: Option<ContentMask<Pixels>>,
413 f: impl FnOnce(&mut Self) -> R,
414 ) -> R {
415 if let Some(mask) = mask {
416 let mask = mask.intersect(&self.content_mask());
417 self.window_mut().next_frame.content_mask_stack.push(mask);
418 let result = f(self);
419 self.window_mut().next_frame.content_mask_stack.pop();
420 result
421 } else {
422 f(self)
423 }
424 }
425
426 /// Invoke the given function with the content mask reset to that
427 /// of the window.
428 pub fn break_content_mask<R>(&mut self, f: impl FnOnce(&mut Self) -> R) -> R {
429 let mask = ContentMask {
430 bounds: Bounds {
431 origin: Point::default(),
432 size: self.window().viewport_size,
433 },
434 };
435
436 let new_root_z_index = post_inc(&mut self.window_mut().next_frame.next_root_z_index);
437 let new_stacking_order_id =
438 post_inc(&mut self.window_mut().next_frame.next_stacking_order_id);
439 let new_context = StackingContext {
440 z_index: new_root_z_index,
441 id: new_stacking_order_id,
442 };
443
444 let old_stacking_order = mem::take(&mut self.window_mut().next_frame.z_index_stack);
445
446 self.window_mut().next_frame.z_index_stack.push(new_context);
447 self.window_mut().next_frame.content_mask_stack.push(mask);
448 let result = f(self);
449 self.window_mut().next_frame.content_mask_stack.pop();
450 self.window_mut().next_frame.z_index_stack = old_stacking_order;
451
452 result
453 }
454
455 /// Called during painting to invoke the given closure in a new stacking context. The given
456 /// z-index is interpreted relative to the previous call to `stack`.
457 pub fn with_z_index<R>(&mut self, z_index: u16, f: impl FnOnce(&mut Self) -> R) -> R {
458 let new_stacking_order_id =
459 post_inc(&mut self.window_mut().next_frame.next_stacking_order_id);
460 let new_context = StackingContext {
461 z_index,
462 id: new_stacking_order_id,
463 };
464
465 self.window_mut().next_frame.z_index_stack.push(new_context);
466 let result = f(self);
467 self.window_mut().next_frame.z_index_stack.pop();
468
469 result
470 }
471
472 /// Updates the global element offset relative to the current offset. This is used to implement
473 /// scrolling.
474 pub fn with_element_offset<R>(
475 &mut self,
476 offset: Point<Pixels>,
477 f: impl FnOnce(&mut Self) -> R,
478 ) -> R {
479 if offset.is_zero() {
480 return f(self);
481 };
482
483 let abs_offset = self.element_offset() + offset;
484 self.with_absolute_element_offset(abs_offset, f)
485 }
486
487 /// Updates the global element offset based on the given offset. This is used to implement
488 /// drag handles and other manual painting of elements.
489 pub fn with_absolute_element_offset<R>(
490 &mut self,
491 offset: Point<Pixels>,
492 f: impl FnOnce(&mut Self) -> R,
493 ) -> R {
494 self.window_mut()
495 .next_frame
496 .element_offset_stack
497 .push(offset);
498 let result = f(self);
499 self.window_mut().next_frame.element_offset_stack.pop();
500 result
501 }
502
503 /// Obtain the current element offset.
504 pub fn element_offset(&self) -> Point<Pixels> {
505 self.window()
506 .next_frame
507 .element_offset_stack
508 .last()
509 .copied()
510 .unwrap_or_default()
511 }
512
513 /// Obtain the current content mask.
514 pub fn content_mask(&self) -> ContentMask<Pixels> {
515 self.window()
516 .next_frame
517 .content_mask_stack
518 .last()
519 .cloned()
520 .unwrap_or_else(|| ContentMask {
521 bounds: Bounds {
522 origin: Point::default(),
523 size: self.window().viewport_size,
524 },
525 })
526 }
527
528 /// The size of an em for the base font of the application. Adjusting this value allows the
529 /// UI to scale, just like zooming a web page.
530 pub fn rem_size(&self) -> Pixels {
531 self.window().rem_size
532 }
533
534 /// Updates or initializes state for an element with the given id that lives across multiple
535 /// frames. If an element with this ID existed in the rendered frame, its state will be passed
536 /// to the given closure. The state returned by the closure will be stored so it can be referenced
537 /// when drawing the next frame.
538 pub fn with_element_state<S, R>(
539 &mut self,
540 id: ElementId,
541 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
542 ) -> R
543 where
544 S: 'static,
545 {
546 self.with_element_id(Some(id), |cx| {
547 let global_id = cx.window().element_id_stack.clone();
548
549 if let Some(any) = cx
550 .window_mut()
551 .next_frame
552 .element_states
553 .remove(&global_id)
554 .or_else(|| {
555 cx.window_mut()
556 .rendered_frame
557 .element_states
558 .remove(&global_id)
559 })
560 {
561 let ElementStateBox {
562 inner,
563 parent_view_id,
564 #[cfg(debug_assertions)]
565 type_name
566 } = any;
567 // Using the extra inner option to avoid needing to reallocate a new box.
568 let mut state_box = inner
569 .downcast::<Option<S>>()
570 .map_err(|_| {
571 #[cfg(debug_assertions)]
572 {
573 anyhow::anyhow!(
574 "invalid element state type for id, requested_type {:?}, actual type: {:?}",
575 std::any::type_name::<S>(),
576 type_name
577 )
578 }
579
580 #[cfg(not(debug_assertions))]
581 {
582 anyhow::anyhow!(
583 "invalid element state type for id, requested_type {:?}",
584 std::any::type_name::<S>(),
585 )
586 }
587 })
588 .unwrap();
589
590 // Actual: Option<AnyElement> <- View
591 // Requested: () <- AnyElement
592 let state = state_box
593 .take()
594 .expect("element state is already on the stack");
595 let (result, state) = f(Some(state), cx);
596 state_box.replace(state);
597 cx.window_mut()
598 .next_frame
599 .element_states
600 .insert(global_id, ElementStateBox {
601 inner: state_box,
602 parent_view_id,
603 #[cfg(debug_assertions)]
604 type_name
605 });
606 result
607 } else {
608 let (result, state) = f(None, cx);
609 let parent_view_id = cx.parent_view_id();
610 cx.window_mut()
611 .next_frame
612 .element_states
613 .insert(global_id,
614 ElementStateBox {
615 inner: Box::new(Some(state)),
616 parent_view_id,
617 #[cfg(debug_assertions)]
618 type_name: std::any::type_name::<S>()
619 }
620
621 );
622 result
623 }
624 })
625 }
626 /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
627 pub fn paint_shadows(
628 &mut self,
629 bounds: Bounds<Pixels>,
630 corner_radii: Corners<Pixels>,
631 shadows: &[BoxShadow],
632 ) {
633 let scale_factor = self.scale_factor();
634 let content_mask = self.content_mask();
635 let view_id = self.parent_view_id();
636 let window = &mut *self.window;
637 for shadow in shadows {
638 let mut shadow_bounds = bounds;
639 shadow_bounds.origin += shadow.offset;
640 shadow_bounds.dilate(shadow.spread_radius);
641 window.next_frame.scene.insert(
642 &window.next_frame.z_index_stack,
643 Shadow {
644 view_id: view_id.into(),
645 layer_id: 0,
646 order: 0,
647 bounds: shadow_bounds.scale(scale_factor),
648 content_mask: content_mask.scale(scale_factor),
649 corner_radii: corner_radii.scale(scale_factor),
650 color: shadow.color,
651 blur_radius: shadow.blur_radius.scale(scale_factor),
652 },
653 );
654 }
655 }
656
657 /// Paint one or more quads into the scene for the next frame at the current stacking context.
658 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
659 /// see [`fill`], [`outline`], and [`quad`] to construct this type.
660 pub fn paint_quad(&mut self, quad: PaintQuad) {
661 let scale_factor = self.scale_factor();
662 let content_mask = self.content_mask();
663 let view_id = self.parent_view_id();
664
665 let window = &mut *self.window;
666 window.next_frame.scene.insert(
667 &window.next_frame.z_index_stack,
668 Quad {
669 view_id: view_id.into(),
670 layer_id: 0,
671 order: 0,
672 bounds: quad.bounds.scale(scale_factor),
673 content_mask: content_mask.scale(scale_factor),
674 background: quad.background,
675 border_color: quad.border_color,
676 corner_radii: quad.corner_radii.scale(scale_factor),
677 border_widths: quad.border_widths.scale(scale_factor),
678 },
679 );
680 }
681
682 /// Paint the given `Path` into the scene for the next frame at the current z-index.
683 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
684 let scale_factor = self.scale_factor();
685 let content_mask = self.content_mask();
686 let view_id = self.parent_view_id();
687
688 path.content_mask = content_mask;
689 path.color = color.into();
690 path.view_id = view_id.into();
691 let window = &mut *self.window;
692 window
693 .next_frame
694 .scene
695 .insert(&window.next_frame.z_index_stack, path.scale(scale_factor));
696 }
697
698 /// Paint an underline into the scene for the next frame at the current z-index.
699 pub fn paint_underline(
700 &mut self,
701 origin: Point<Pixels>,
702 width: Pixels,
703 style: &UnderlineStyle,
704 ) {
705 let scale_factor = self.scale_factor();
706 let height = if style.wavy {
707 style.thickness * 3.
708 } else {
709 style.thickness
710 };
711 let bounds = Bounds {
712 origin,
713 size: size(width, height),
714 };
715 let content_mask = self.content_mask();
716 let view_id = self.parent_view_id();
717
718 let window = &mut *self.window;
719 window.next_frame.scene.insert(
720 &window.next_frame.z_index_stack,
721 Underline {
722 view_id: view_id.into(),
723 layer_id: 0,
724 order: 0,
725 bounds: bounds.scale(scale_factor),
726 content_mask: content_mask.scale(scale_factor),
727 thickness: style.thickness.scale(scale_factor),
728 color: style.color.unwrap_or_default(),
729 wavy: style.wavy,
730 },
731 );
732 }
733
734 /// Paint a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
735 /// The y component of the origin is the baseline of the glyph.
736 /// You should generally prefer to use the [`ShapedLine::paint`] or [`WrappedLine::paint`] methods in the [`text_system`].
737 /// This method is only useful if you need to paint a single glyph that has already been shaped.
738 pub fn paint_glyph(
739 &mut self,
740 origin: Point<Pixels>,
741 font_id: FontId,
742 glyph_id: GlyphId,
743 font_size: Pixels,
744 color: Hsla,
745 ) -> Result<()> {
746 let scale_factor = self.scale_factor();
747 let glyph_origin = origin.scale(scale_factor);
748 let subpixel_variant = Point {
749 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
750 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
751 };
752 let params = RenderGlyphParams {
753 font_id,
754 glyph_id,
755 font_size,
756 subpixel_variant,
757 scale_factor,
758 is_emoji: false,
759 };
760
761 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
762 if !raster_bounds.is_zero() {
763 let tile =
764 self.window
765 .sprite_atlas
766 .get_or_insert_with(¶ms.clone().into(), &mut || {
767 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
768 Ok((size, Cow::Owned(bytes)))
769 })?;
770 let bounds = Bounds {
771 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
772 size: tile.bounds.size.map(Into::into),
773 };
774 let content_mask = self.content_mask().scale(scale_factor);
775 let view_id = self.parent_view_id();
776 let window = &mut *self.window;
777 window.next_frame.scene.insert(
778 &window.next_frame.z_index_stack,
779 MonochromeSprite {
780 view_id: view_id.into(),
781 layer_id: 0,
782 order: 0,
783 bounds,
784 content_mask,
785 color,
786 tile,
787 },
788 );
789 }
790 Ok(())
791 }
792
793 /// Paint an emoji glyph into the scene for the next frame at the current z-index.
794 /// The y component of the origin is the baseline of the glyph.
795 /// You should generally prefer to use the [`ShapedLine::paint`] or [`WrappedLine::paint`] methods in the [`text_system`].
796 /// This method is only useful if you need to paint a single emoji that has already been shaped.
797 pub fn paint_emoji(
798 &mut self,
799 origin: Point<Pixels>,
800 font_id: FontId,
801 glyph_id: GlyphId,
802 font_size: Pixels,
803 ) -> Result<()> {
804 let scale_factor = self.scale_factor();
805 let glyph_origin = origin.scale(scale_factor);
806 let params = RenderGlyphParams {
807 font_id,
808 glyph_id,
809 font_size,
810 // We don't render emojis with subpixel variants.
811 subpixel_variant: Default::default(),
812 scale_factor,
813 is_emoji: true,
814 };
815
816 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
817 if !raster_bounds.is_zero() {
818 let tile =
819 self.window
820 .sprite_atlas
821 .get_or_insert_with(¶ms.clone().into(), &mut || {
822 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
823 Ok((size, Cow::Owned(bytes)))
824 })?;
825 let bounds = Bounds {
826 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
827 size: tile.bounds.size.map(Into::into),
828 };
829 let content_mask = self.content_mask().scale(scale_factor);
830 let view_id = self.parent_view_id();
831 let window = &mut *self.window;
832
833 window.next_frame.scene.insert(
834 &window.next_frame.z_index_stack,
835 PolychromeSprite {
836 view_id: view_id.into(),
837 layer_id: 0,
838 order: 0,
839 bounds,
840 corner_radii: Default::default(),
841 content_mask,
842 tile,
843 grayscale: false,
844 },
845 );
846 }
847 Ok(())
848 }
849
850 /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
851 pub fn paint_svg(
852 &mut self,
853 bounds: Bounds<Pixels>,
854 path: SharedString,
855 color: Hsla,
856 ) -> Result<()> {
857 let scale_factor = self.scale_factor();
858 let bounds = bounds.scale(scale_factor);
859 // Render the SVG at twice the size to get a higher quality result.
860 let params = RenderSvgParams {
861 path,
862 size: bounds
863 .size
864 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
865 };
866
867 let tile =
868 self.window
869 .sprite_atlas
870 .get_or_insert_with(¶ms.clone().into(), &mut || {
871 let bytes = self.svg_renderer.render(¶ms)?;
872 Ok((params.size, Cow::Owned(bytes)))
873 })?;
874 let content_mask = self.content_mask().scale(scale_factor);
875 let view_id = self.parent_view_id();
876
877 let window = &mut *self.window;
878 window.next_frame.scene.insert(
879 &window.next_frame.z_index_stack,
880 MonochromeSprite {
881 view_id: view_id.into(),
882 layer_id: 0,
883 order: 0,
884 bounds,
885 content_mask,
886 color,
887 tile,
888 },
889 );
890
891 Ok(())
892 }
893
894 /// Paint an image into the scene for the next frame at the current z-index.
895 pub fn paint_image(
896 &mut self,
897 bounds: Bounds<Pixels>,
898 corner_radii: Corners<Pixels>,
899 data: Arc<ImageData>,
900 grayscale: bool,
901 ) -> Result<()> {
902 let scale_factor = self.scale_factor();
903 let bounds = bounds.scale(scale_factor);
904 let params = RenderImageParams { image_id: data.id };
905
906 let tile = self
907 .window
908 .sprite_atlas
909 .get_or_insert_with(¶ms.clone().into(), &mut || {
910 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
911 })?;
912 let content_mask = self.content_mask().scale(scale_factor);
913 let corner_radii = corner_radii.scale(scale_factor);
914 let view_id = self.parent_view_id();
915
916 let window = &mut *self.window;
917 window.next_frame.scene.insert(
918 &window.next_frame.z_index_stack,
919 PolychromeSprite {
920 view_id: view_id.into(),
921 layer_id: 0,
922 order: 0,
923 bounds,
924 content_mask,
925 corner_radii,
926 tile,
927 grayscale,
928 },
929 );
930 Ok(())
931 }
932
933 /// Paint a surface into the scene for the next frame at the current z-index.
934 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
935 let scale_factor = self.scale_factor();
936 let bounds = bounds.scale(scale_factor);
937 let content_mask = self.content_mask().scale(scale_factor);
938 let view_id = self.parent_view_id();
939 let window = &mut *self.window;
940 window.next_frame.scene.insert(
941 &window.next_frame.z_index_stack,
942 Surface {
943 view_id: view_id.into(),
944 layer_id: 0,
945 order: 0,
946 bounds,
947 content_mask,
948 image_buffer,
949 },
950 );
951 }
952
953 #[must_use]
954 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
955 /// layout is being requested, along with the layout ids of any children. This method is called during
956 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
957 pub fn request_layout(
958 &mut self,
959 style: &Style,
960 children: impl IntoIterator<Item = LayoutId>,
961 ) -> LayoutId {
962 self.app.layout_id_buffer.clear();
963 self.app.layout_id_buffer.extend(children);
964 let rem_size = self.rem_size();
965
966 self.cx
967 .window
968 .layout_engine
969 .as_mut()
970 .unwrap()
971 .request_layout(style, rem_size, &self.cx.app.layout_id_buffer)
972 }
973
974 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
975 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
976 /// determine the element's size. One place this is used internally is when measuring text.
977 ///
978 /// The given closure is invoked at layout time with the known dimensions and available space and
979 /// returns a `Size`.
980 pub fn request_measured_layout<
981 F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut WindowContext) -> Size<Pixels>
982 + 'static,
983 >(
984 &mut self,
985 style: Style,
986 measure: F,
987 ) -> LayoutId {
988 let rem_size = self.rem_size();
989 self.window
990 .layout_engine
991 .as_mut()
992 .unwrap()
993 .request_measured_layout(style, rem_size, measure)
994 }
995
996 /// Compute the layout for the given id within the given available space.
997 /// This method is called for its side effect, typically by the framework prior to painting.
998 /// After calling it, you can request the bounds of the given layout node id or any descendant.
999 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
1000 let mut layout_engine = self.window.layout_engine.take().unwrap();
1001 layout_engine.compute_layout(layout_id, available_space, self);
1002 self.window.layout_engine = Some(layout_engine);
1003 }
1004
1005 /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
1006 /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
1007 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
1008 let mut bounds = self
1009 .window
1010 .layout_engine
1011 .as_mut()
1012 .unwrap()
1013 .layout_bounds(layout_id)
1014 .map(Into::into);
1015 bounds.origin += self.element_offset();
1016 bounds
1017 }
1018
1019 pub(crate) fn layout_style(&self, layout_id: LayoutId) -> Option<&Style> {
1020 self.window
1021 .layout_engine
1022 .as_ref()
1023 .unwrap()
1024 .requested_style(layout_id)
1025 }
1026
1027 /// Called during painting to track which z-index is on top at each pixel position
1028 pub fn add_opaque_layer(&mut self, bounds: Bounds<Pixels>) {
1029 let stacking_order = self.window.next_frame.z_index_stack.clone();
1030 let view_id = self.parent_view_id();
1031 let depth_map = &mut self.window.next_frame.depth_map;
1032 match depth_map.binary_search_by(|(level, _, _)| stacking_order.cmp(level)) {
1033 Ok(i) | Err(i) => depth_map.insert(i, (stacking_order, view_id, bounds)),
1034 }
1035 }
1036
1037 /// Invoke the given function with the given focus handle present on the key dispatch stack.
1038 /// If you want an element to participate in key dispatch, use this method to push its key context and focus handle into the stack during paint.
1039 pub fn with_key_dispatch<R>(
1040 &mut self,
1041 context: Option<KeyContext>,
1042 focus_handle: Option<FocusHandle>,
1043 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1044 ) -> R {
1045 let window = &mut self.window;
1046 let focus_id = focus_handle.as_ref().map(|handle| handle.id);
1047 window
1048 .next_frame
1049 .dispatch_tree
1050 .push_node(context.clone(), focus_id, None);
1051
1052 let result = f(focus_handle, self);
1053
1054 self.window.next_frame.dispatch_tree.pop_node();
1055
1056 result
1057 }
1058
1059 /// Invoke the given function with the given view id present on the view stack.
1060 /// This is a fairly low-level method used to layout views.
1061 pub fn with_view_id<R>(&mut self, view_id: EntityId, f: impl FnOnce(&mut Self) -> R) -> R {
1062 let text_system = self.text_system().clone();
1063 text_system.with_view(view_id, || {
1064 if self.window.next_frame.view_stack.last() == Some(&view_id) {
1065 f(self)
1066 } else {
1067 self.window.next_frame.view_stack.push(view_id);
1068 let result = f(self);
1069 self.window.next_frame.view_stack.pop();
1070 result
1071 }
1072 })
1073 }
1074
1075 /// Invoke the given function with the given view id present on the view stack.
1076 /// This is a fairly low-level method used to paint views.
1077 pub fn paint_view<R>(&mut self, view_id: EntityId, f: impl FnOnce(&mut Self) -> R) -> R {
1078 let text_system = self.text_system().clone();
1079 text_system.with_view(view_id, || {
1080 if self.window.next_frame.view_stack.last() == Some(&view_id) {
1081 f(self)
1082 } else {
1083 self.window.next_frame.view_stack.push(view_id);
1084 self.window
1085 .next_frame
1086 .dispatch_tree
1087 .push_node(None, None, Some(view_id));
1088 let result = f(self);
1089 self.window.next_frame.dispatch_tree.pop_node();
1090 self.window.next_frame.view_stack.pop();
1091 result
1092 }
1093 })
1094 }
1095
1096 /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
1097 /// platform to receive textual input with proper integration with concerns such
1098 /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
1099 /// rendered.
1100 ///
1101 /// [element_input_handler]: crate::ElementInputHandler
1102 pub fn handle_input(&mut self, focus_handle: &FocusHandle, input_handler: impl InputHandler) {
1103 if focus_handle.is_focused(self) {
1104 let view_id = self.parent_view_id();
1105 self.window.next_frame.requested_input_handler = Some(RequestedInputHandler {
1106 view_id,
1107 handler: Some(PlatformInputHandler::new(
1108 self.to_async(),
1109 Box::new(input_handler),
1110 )),
1111 })
1112 }
1113 }
1114
1115 /// keymatch mode immediate instructs GPUI to prefer shorter action bindings.
1116 /// In the case that you have a keybinding of `"cmd-k": "terminal::Clear"` and
1117 /// `"cmd-k left": "workspace::MoveLeft"`, GPUI will by default wait for 1s after
1118 /// you type cmd-k to see if you're going to type left.
1119 /// This is problematic in the terminal
1120 pub fn keymatch_mode_immediate(&mut self) {
1121 self.window.next_frame.dispatch_tree.keymatch_mode = KeymatchMode::Immediate;
1122 }
1123
1124 /// Register a mouse event listener on the window for the next frame. The type of event
1125 /// is determined by the first parameter of the given listener. When the next frame is rendered
1126 /// the listener will be cleared.
1127 pub fn on_mouse_event<Event: MouseEvent>(
1128 &mut self,
1129 mut handler: impl FnMut(&Event, DispatchPhase, &mut ElementContext) + 'static,
1130 ) {
1131 let view_id = self.parent_view_id();
1132 let order = self.window.next_frame.z_index_stack.clone();
1133 self.window
1134 .next_frame
1135 .mouse_listeners
1136 .entry(TypeId::of::<Event>())
1137 .or_default()
1138 .push((
1139 order,
1140 view_id,
1141 Box::new(
1142 move |event: &dyn Any, phase: DispatchPhase, cx: &mut ElementContext<'_>| {
1143 handler(event.downcast_ref().unwrap(), phase, cx)
1144 },
1145 ),
1146 ))
1147 }
1148
1149 /// Register a key event listener on the window for the next frame. The type of event
1150 /// is determined by the first parameter of the given listener. When the next frame is rendered
1151 /// the listener will be cleared.
1152 ///
1153 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
1154 /// a specific need to register a global listener.
1155 pub fn on_key_event<Event: KeyEvent>(
1156 &mut self,
1157 listener: impl Fn(&Event, DispatchPhase, &mut ElementContext) + 'static,
1158 ) {
1159 self.window.next_frame.dispatch_tree.on_key_event(Rc::new(
1160 move |event: &dyn Any, phase, cx: &mut ElementContext<'_>| {
1161 if let Some(event) = event.downcast_ref::<Event>() {
1162 listener(event, phase, cx)
1163 }
1164 },
1165 ));
1166 }
1167}