1use crate::{
2 hash, point, prelude::*, px, size, transparent_black, Action, AnyDrag, AnyElement, AnyTooltip,
3 AnyView, AppContext, Arena, Asset, AsyncWindowContext, AvailableSpace, Bounds, BoxShadow,
4 Context, Corners, CursorStyle, DevicePixels, DispatchActionListener, DispatchNodeId,
5 DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter, FileDropEvent, Flatten,
6 FontId, Global, GlobalElementId, GlyphId, Hsla, ImageData, InputHandler, IsZero, KeyBinding,
7 KeyContext, KeyDownEvent, KeyEvent, KeyMatch, KeymatchResult, Keystroke, KeystrokeEvent,
8 LayoutId, LineLayoutIndex, Model, ModelContext, Modifiers, ModifiersChangedEvent,
9 MonochromeSprite, MouseButton, MouseEvent, MouseMoveEvent, MouseUpEvent, Path, Pixels,
10 PlatformAtlas, PlatformDisplay, PlatformInput, PlatformInputHandler, PlatformWindow, Point,
11 PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams, RenderImageParams,
12 RenderSvgParams, ScaledPixels, Scene, Shadow, SharedString, Size, StrikethroughStyle, Style,
13 SubscriberSet, Subscription, TaffyLayoutEngine, Task, TextStyle, TextStyleRefinement,
14 TransformationMatrix, Underline, UnderlineStyle, View, VisualContext, WeakView,
15 WindowAppearance, WindowBackgroundAppearance, WindowBounds, WindowOptions, WindowParams,
16 WindowTextSystem, SUBPIXEL_VARIANTS,
17};
18use anyhow::{anyhow, Context as _, Result};
19use collections::{FxHashMap, FxHashSet};
20use derive_more::{Deref, DerefMut};
21use futures::channel::oneshot;
22use futures::{future::Shared, FutureExt};
23#[cfg(target_os = "macos")]
24use media::core_video::CVImageBuffer;
25use parking_lot::RwLock;
26use refineable::Refineable;
27use slotmap::SlotMap;
28use smallvec::SmallVec;
29use std::{
30 any::{Any, TypeId},
31 borrow::{Borrow, BorrowMut, Cow},
32 cell::{Cell, RefCell},
33 cmp,
34 fmt::{Debug, Display},
35 future::Future,
36 hash::{Hash, Hasher},
37 marker::PhantomData,
38 mem,
39 ops::Range,
40 rc::Rc,
41 sync::{
42 atomic::{AtomicUsize, Ordering::SeqCst},
43 Arc, Weak,
44 },
45 time::{Duration, Instant},
46};
47use util::post_inc;
48use util::{measure, ResultExt};
49use uuid::Uuid;
50
51mod prompts;
52
53pub use prompts::*;
54
55pub(crate) const DEFAULT_WINDOW_SIZE: Size<Pixels> = size(px(1024.), px(700.));
56
57/// Represents the two different phases when dispatching events.
58#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
59pub enum DispatchPhase {
60 /// After the capture phase comes the bubble phase, in which mouse event listeners are
61 /// invoked front to back and keyboard event listeners are invoked from the focused element
62 /// to the root of the element tree. This is the phase you'll most commonly want to use when
63 /// registering event listeners.
64 #[default]
65 Bubble,
66 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
67 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
68 /// is used for special purposes such as clearing the "pressed" state for click events. If
69 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
70 /// outside of the immediate region may rely on detecting non-local events during this phase.
71 Capture,
72}
73
74impl DispatchPhase {
75 /// Returns true if this represents the "bubble" phase.
76 pub fn bubble(self) -> bool {
77 self == DispatchPhase::Bubble
78 }
79
80 /// Returns true if this represents the "capture" phase.
81 pub fn capture(self) -> bool {
82 self == DispatchPhase::Capture
83 }
84}
85
86type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
87
88type AnyWindowFocusListener =
89 Box<dyn FnMut(&WindowFocusEvent, &mut WindowContext) -> bool + 'static>;
90
91struct WindowFocusEvent {
92 previous_focus_path: SmallVec<[FocusId; 8]>,
93 current_focus_path: SmallVec<[FocusId; 8]>,
94}
95
96/// This is provided when subscribing for `ViewContext::on_focus_out` events.
97pub struct FocusOutEvent {
98 /// A weak focus handle representing what was blurred.
99 pub blurred: WeakFocusHandle,
100}
101
102slotmap::new_key_type! {
103 /// A globally unique identifier for a focusable element.
104 pub struct FocusId;
105}
106
107thread_local! {
108 /// 8MB wasn't quite enough...
109 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(32 * 1024 * 1024));
110}
111
112impl FocusId {
113 /// Obtains whether the element associated with this handle is currently focused.
114 pub fn is_focused(&self, cx: &WindowContext) -> bool {
115 cx.window.focus == Some(*self)
116 }
117
118 /// Obtains whether the element associated with this handle contains the focused
119 /// element or is itself focused.
120 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
121 cx.focused()
122 .map_or(false, |focused| self.contains(focused.id, cx))
123 }
124
125 /// Obtains whether the element associated with this handle is contained within the
126 /// focused element or is itself focused.
127 pub fn within_focused(&self, cx: &WindowContext) -> bool {
128 let focused = cx.focused();
129 focused.map_or(false, |focused| focused.id.contains(*self, cx))
130 }
131
132 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
133 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
134 cx.window
135 .rendered_frame
136 .dispatch_tree
137 .focus_contains(*self, other)
138 }
139}
140
141/// A handle which can be used to track and manipulate the focused element in a window.
142pub struct FocusHandle {
143 pub(crate) id: FocusId,
144 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
145}
146
147impl std::fmt::Debug for FocusHandle {
148 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
149 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
150 }
151}
152
153impl FocusHandle {
154 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
155 let id = handles.write().insert(AtomicUsize::new(1));
156 Self {
157 id,
158 handles: handles.clone(),
159 }
160 }
161
162 pub(crate) fn for_id(
163 id: FocusId,
164 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
165 ) -> Option<Self> {
166 let lock = handles.read();
167 let ref_count = lock.get(id)?;
168 if ref_count.load(SeqCst) == 0 {
169 None
170 } else {
171 ref_count.fetch_add(1, SeqCst);
172 Some(Self {
173 id,
174 handles: handles.clone(),
175 })
176 }
177 }
178
179 /// Converts this focus handle into a weak variant, which does not prevent it from being released.
180 pub fn downgrade(&self) -> WeakFocusHandle {
181 WeakFocusHandle {
182 id: self.id,
183 handles: Arc::downgrade(&self.handles),
184 }
185 }
186
187 /// Moves the focus to the element associated with this handle.
188 pub fn focus(&self, cx: &mut WindowContext) {
189 cx.focus(self)
190 }
191
192 /// Obtains whether the element associated with this handle is currently focused.
193 pub fn is_focused(&self, cx: &WindowContext) -> bool {
194 self.id.is_focused(cx)
195 }
196
197 /// Obtains whether the element associated with this handle contains the focused
198 /// element or is itself focused.
199 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
200 self.id.contains_focused(cx)
201 }
202
203 /// Obtains whether the element associated with this handle is contained within the
204 /// focused element or is itself focused.
205 pub fn within_focused(&self, cx: &WindowContext) -> bool {
206 self.id.within_focused(cx)
207 }
208
209 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
210 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
211 self.id.contains(other.id, cx)
212 }
213
214 /// Dispatch an action on the element that rendered this focus handle
215 pub fn dispatch_action(&self, action: &dyn Action, cx: &mut WindowContext) {
216 if let Some(node_id) = cx
217 .window
218 .rendered_frame
219 .dispatch_tree
220 .focusable_node_id(self.id)
221 {
222 cx.dispatch_action_on_node(node_id, action)
223 }
224 }
225}
226
227impl Clone for FocusHandle {
228 fn clone(&self) -> Self {
229 Self::for_id(self.id, &self.handles).unwrap()
230 }
231}
232
233impl PartialEq for FocusHandle {
234 fn eq(&self, other: &Self) -> bool {
235 self.id == other.id
236 }
237}
238
239impl Eq for FocusHandle {}
240
241impl Drop for FocusHandle {
242 fn drop(&mut self) {
243 self.handles
244 .read()
245 .get(self.id)
246 .unwrap()
247 .fetch_sub(1, SeqCst);
248 }
249}
250
251/// A weak reference to a focus handle.
252#[derive(Clone, Debug)]
253pub struct WeakFocusHandle {
254 pub(crate) id: FocusId,
255 handles: Weak<RwLock<SlotMap<FocusId, AtomicUsize>>>,
256}
257
258impl WeakFocusHandle {
259 /// Attempts to upgrade the [WeakFocusHandle] to a [FocusHandle].
260 pub fn upgrade(&self) -> Option<FocusHandle> {
261 let handles = self.handles.upgrade()?;
262 FocusHandle::for_id(self.id, &handles)
263 }
264}
265
266impl PartialEq for WeakFocusHandle {
267 fn eq(&self, other: &WeakFocusHandle) -> bool {
268 self.id == other.id
269 }
270}
271
272impl Eq for WeakFocusHandle {}
273
274impl PartialEq<FocusHandle> for WeakFocusHandle {
275 fn eq(&self, other: &FocusHandle) -> bool {
276 self.id == other.id
277 }
278}
279
280impl PartialEq<WeakFocusHandle> for FocusHandle {
281 fn eq(&self, other: &WeakFocusHandle) -> bool {
282 self.id == other.id
283 }
284}
285
286/// FocusableView allows users of your view to easily
287/// focus it (using cx.focus_view(view))
288pub trait FocusableView: 'static + Render {
289 /// Returns the focus handle associated with this view.
290 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
291}
292
293/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
294/// where the lifecycle of the view is handled by another view.
295pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
296
297impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
298
299/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
300pub struct DismissEvent;
301
302type FrameCallback = Box<dyn FnOnce(&mut WindowContext)>;
303
304pub(crate) type AnyMouseListener =
305 Box<dyn FnMut(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
306
307#[derive(Clone)]
308pub(crate) struct CursorStyleRequest {
309 pub(crate) hitbox_id: HitboxId,
310 pub(crate) style: CursorStyle,
311}
312
313/// An identifier for a [Hitbox].
314#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
315pub struct HitboxId(usize);
316
317impl HitboxId {
318 /// Checks if the hitbox with this id is currently hovered.
319 pub fn is_hovered(&self, cx: &WindowContext) -> bool {
320 cx.window.mouse_hit_test.0.contains(self)
321 }
322}
323
324/// A rectangular region that potentially blocks hitboxes inserted prior.
325/// See [WindowContext::insert_hitbox] for more details.
326#[derive(Clone, Debug, Deref)]
327pub struct Hitbox {
328 /// A unique identifier for the hitbox.
329 pub id: HitboxId,
330 /// The bounds of the hitbox.
331 #[deref]
332 pub bounds: Bounds<Pixels>,
333 /// The content mask when the hitbox was inserted.
334 pub content_mask: ContentMask<Pixels>,
335 /// Whether the hitbox occludes other hitboxes inserted prior.
336 pub opaque: bool,
337}
338
339impl Hitbox {
340 /// Checks if the hitbox is currently hovered.
341 pub fn is_hovered(&self, cx: &WindowContext) -> bool {
342 self.id.is_hovered(cx)
343 }
344}
345
346#[derive(Default, Eq, PartialEq)]
347pub(crate) struct HitTest(SmallVec<[HitboxId; 8]>);
348
349/// An identifier for a tooltip.
350#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
351pub struct TooltipId(usize);
352
353impl TooltipId {
354 /// Checks if the tooltip is currently hovered.
355 pub fn is_hovered(&self, cx: &WindowContext) -> bool {
356 cx.window
357 .tooltip_bounds
358 .as_ref()
359 .map_or(false, |tooltip_bounds| {
360 tooltip_bounds.id == *self && tooltip_bounds.bounds.contains(&cx.mouse_position())
361 })
362 }
363}
364
365pub(crate) struct TooltipBounds {
366 id: TooltipId,
367 bounds: Bounds<Pixels>,
368}
369
370#[derive(Clone)]
371pub(crate) struct TooltipRequest {
372 id: TooltipId,
373 tooltip: AnyTooltip,
374}
375
376pub(crate) struct DeferredDraw {
377 priority: usize,
378 parent_node: DispatchNodeId,
379 element_id_stack: SmallVec<[ElementId; 32]>,
380 text_style_stack: Vec<TextStyleRefinement>,
381 element: Option<AnyElement>,
382 absolute_offset: Point<Pixels>,
383 prepaint_range: Range<PrepaintStateIndex>,
384 paint_range: Range<PaintIndex>,
385}
386
387pub(crate) struct Frame {
388 pub(crate) focus: Option<FocusId>,
389 pub(crate) window_active: bool,
390 pub(crate) element_states: FxHashMap<(GlobalElementId, TypeId), ElementStateBox>,
391 accessed_element_states: Vec<(GlobalElementId, TypeId)>,
392 pub(crate) mouse_listeners: Vec<Option<AnyMouseListener>>,
393 pub(crate) dispatch_tree: DispatchTree,
394 pub(crate) scene: Scene,
395 pub(crate) hitboxes: Vec<Hitbox>,
396 pub(crate) deferred_draws: Vec<DeferredDraw>,
397 pub(crate) input_handlers: Vec<Option<PlatformInputHandler>>,
398 pub(crate) tooltip_requests: Vec<Option<TooltipRequest>>,
399 pub(crate) cursor_styles: Vec<CursorStyleRequest>,
400 #[cfg(any(test, feature = "test-support"))]
401 pub(crate) debug_bounds: FxHashMap<String, Bounds<Pixels>>,
402}
403
404#[derive(Clone, Default)]
405pub(crate) struct PrepaintStateIndex {
406 hitboxes_index: usize,
407 tooltips_index: usize,
408 deferred_draws_index: usize,
409 dispatch_tree_index: usize,
410 accessed_element_states_index: usize,
411 line_layout_index: LineLayoutIndex,
412}
413
414#[derive(Clone, Default)]
415pub(crate) struct PaintIndex {
416 scene_index: usize,
417 mouse_listeners_index: usize,
418 input_handlers_index: usize,
419 cursor_styles_index: usize,
420 accessed_element_states_index: usize,
421 line_layout_index: LineLayoutIndex,
422}
423
424impl Frame {
425 pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
426 Frame {
427 focus: None,
428 window_active: false,
429 element_states: FxHashMap::default(),
430 accessed_element_states: Vec::new(),
431 mouse_listeners: Vec::new(),
432 dispatch_tree,
433 scene: Scene::default(),
434 hitboxes: Vec::new(),
435 deferred_draws: Vec::new(),
436 input_handlers: Vec::new(),
437 tooltip_requests: Vec::new(),
438 cursor_styles: Vec::new(),
439
440 #[cfg(any(test, feature = "test-support"))]
441 debug_bounds: FxHashMap::default(),
442 }
443 }
444
445 pub(crate) fn clear(&mut self) {
446 self.element_states.clear();
447 self.accessed_element_states.clear();
448 self.mouse_listeners.clear();
449 self.dispatch_tree.clear();
450 self.scene.clear();
451 self.input_handlers.clear();
452 self.tooltip_requests.clear();
453 self.cursor_styles.clear();
454 self.hitboxes.clear();
455 self.deferred_draws.clear();
456 }
457
458 pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
459 let mut hit_test = HitTest::default();
460 for hitbox in self.hitboxes.iter().rev() {
461 let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
462 if bounds.contains(&position) {
463 hit_test.0.push(hitbox.id);
464 if hitbox.opaque {
465 break;
466 }
467 }
468 }
469 hit_test
470 }
471
472 pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
473 self.focus
474 .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
475 .unwrap_or_default()
476 }
477
478 pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
479 for element_state_key in &self.accessed_element_states {
480 if let Some((element_state_key, element_state)) =
481 prev_frame.element_states.remove_entry(element_state_key)
482 {
483 self.element_states.insert(element_state_key, element_state);
484 }
485 }
486
487 self.scene.finish();
488 }
489}
490
491// Holds the state for a specific window.
492#[doc(hidden)]
493pub struct Window {
494 pub(crate) handle: AnyWindowHandle,
495 pub(crate) removed: bool,
496 pub(crate) platform_window: Box<dyn PlatformWindow>,
497 display_id: Option<DisplayId>,
498 sprite_atlas: Arc<dyn PlatformAtlas>,
499 text_system: Arc<WindowTextSystem>,
500 rem_size: Pixels,
501 /// The stack of override values for the window's rem size.
502 ///
503 /// This is used by `with_rem_size` to allow rendering an element tree with
504 /// a given rem size.
505 rem_size_override_stack: SmallVec<[Pixels; 8]>,
506 pub(crate) viewport_size: Size<Pixels>,
507 layout_engine: Option<TaffyLayoutEngine>,
508 pub(crate) root_view: Option<AnyView>,
509 pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
510 pub(crate) text_style_stack: Vec<TextStyleRefinement>,
511 pub(crate) element_offset_stack: Vec<Point<Pixels>>,
512 pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
513 pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
514 pub(crate) rendered_frame: Frame,
515 pub(crate) next_frame: Frame,
516 pub(crate) next_hitbox_id: HitboxId,
517 pub(crate) next_tooltip_id: TooltipId,
518 pub(crate) tooltip_bounds: Option<TooltipBounds>,
519 next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
520 pub(crate) dirty_views: FxHashSet<EntityId>,
521 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
522 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
523 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
524 default_prevented: bool,
525 mouse_position: Point<Pixels>,
526 mouse_hit_test: HitTest,
527 modifiers: Modifiers,
528 scale_factor: f32,
529 bounds_observers: SubscriberSet<(), AnyObserver>,
530 appearance: WindowAppearance,
531 appearance_observers: SubscriberSet<(), AnyObserver>,
532 active: Rc<Cell<bool>>,
533 pub(crate) dirty: Rc<Cell<bool>>,
534 pub(crate) needs_present: Rc<Cell<bool>>,
535 pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
536 pub(crate) refreshing: bool,
537 pub(crate) draw_phase: DrawPhase,
538 activation_observers: SubscriberSet<(), AnyObserver>,
539 pub(crate) focus: Option<FocusId>,
540 focus_enabled: bool,
541 pending_input: Option<PendingInput>,
542 pending_input_observers: SubscriberSet<(), AnyObserver>,
543 prompt: Option<RenderablePromptHandle>,
544}
545
546#[derive(Clone, Copy, Debug, Eq, PartialEq)]
547pub(crate) enum DrawPhase {
548 None,
549 Prepaint,
550 Paint,
551 Focus,
552}
553
554#[derive(Default, Debug)]
555struct PendingInput {
556 keystrokes: SmallVec<[Keystroke; 1]>,
557 bindings: SmallVec<[KeyBinding; 1]>,
558 focus: Option<FocusId>,
559 timer: Option<Task<()>>,
560}
561
562impl PendingInput {
563 fn input(&self) -> String {
564 self.keystrokes
565 .iter()
566 .flat_map(|k| k.ime_key.clone())
567 .collect::<Vec<String>>()
568 .join("")
569 }
570
571 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
572 if self.keystrokes.is_empty() {
573 return true;
574 }
575 let keystroke = &self.keystrokes[0];
576 for candidate in keystroke.match_candidates() {
577 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
578 return true;
579 }
580 }
581 false
582 }
583}
584
585pub(crate) struct ElementStateBox {
586 pub(crate) inner: Box<dyn Any>,
587 #[cfg(debug_assertions)]
588 pub(crate) type_name: &'static str,
589}
590
591fn default_bounds(display_id: Option<DisplayId>, cx: &mut AppContext) -> Bounds<Pixels> {
592 const DEFAULT_WINDOW_OFFSET: Point<Pixels> = point(px(0.), px(35.));
593
594 cx.active_window()
595 .and_then(|w| w.update(cx, |_, cx| cx.bounds()).ok())
596 .map(|bounds| bounds.map_origin(|origin| origin + DEFAULT_WINDOW_OFFSET))
597 .unwrap_or_else(|| {
598 let display = display_id
599 .map(|id| cx.find_display(id))
600 .unwrap_or_else(|| cx.primary_display());
601
602 display
603 .map(|display| display.default_bounds())
604 .unwrap_or_else(|| Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE))
605 })
606}
607
608impl Window {
609 pub(crate) fn new(
610 handle: AnyWindowHandle,
611 options: WindowOptions,
612 cx: &mut AppContext,
613 ) -> Result<Self> {
614 let WindowOptions {
615 window_bounds,
616 titlebar,
617 focus,
618 show,
619 kind,
620 is_movable,
621 display_id,
622 window_background,
623 app_id,
624 } = options;
625
626 let bounds = window_bounds
627 .map(|bounds| bounds.get_bounds())
628 .unwrap_or_else(|| default_bounds(display_id, cx));
629 let mut platform_window = cx.platform.open_window(
630 handle,
631 WindowParams {
632 bounds,
633 titlebar,
634 kind,
635 is_movable,
636 focus,
637 show,
638 display_id,
639 window_background,
640 },
641 )?;
642 let display_id = platform_window.display().map(|display| display.id());
643 let sprite_atlas = platform_window.sprite_atlas();
644 let mouse_position = platform_window.mouse_position();
645 let modifiers = platform_window.modifiers();
646 let content_size = platform_window.content_size();
647 let scale_factor = platform_window.scale_factor();
648 let appearance = platform_window.appearance();
649 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
650 let dirty = Rc::new(Cell::new(true));
651 let active = Rc::new(Cell::new(platform_window.is_active()));
652 let needs_present = Rc::new(Cell::new(false));
653 let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
654 let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
655
656 if let Some(ref window_open_state) = window_bounds {
657 match window_open_state {
658 WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
659 WindowBounds::Maximized(_) => platform_window.zoom(),
660 WindowBounds::Windowed(_) => {}
661 }
662 }
663
664 platform_window.on_close(Box::new({
665 let mut cx = cx.to_async();
666 move || {
667 let _ = handle.update(&mut cx, |_, cx| cx.remove_window());
668 }
669 }));
670 platform_window.on_request_frame(Box::new({
671 let mut cx = cx.to_async();
672 let dirty = dirty.clone();
673 let active = active.clone();
674 let needs_present = needs_present.clone();
675 let next_frame_callbacks = next_frame_callbacks.clone();
676 let last_input_timestamp = last_input_timestamp.clone();
677 move || {
678 let next_frame_callbacks = next_frame_callbacks.take();
679 if !next_frame_callbacks.is_empty() {
680 handle
681 .update(&mut cx, |_, cx| {
682 for callback in next_frame_callbacks {
683 callback(cx);
684 }
685 })
686 .log_err();
687 }
688
689 // Keep presenting the current scene for 1 extra second since the
690 // last input to prevent the display from underclocking the refresh rate.
691 let needs_present = needs_present.get()
692 || (active.get()
693 && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
694
695 if dirty.get() {
696 measure("frame duration", || {
697 handle
698 .update(&mut cx, |_, cx| {
699 cx.draw();
700 cx.present();
701 })
702 .log_err();
703 })
704 } else if needs_present {
705 handle.update(&mut cx, |_, cx| cx.present()).log_err();
706 }
707
708 handle
709 .update(&mut cx, |_, cx| {
710 cx.complete_frame();
711 })
712 .log_err();
713 }
714 }));
715 platform_window.on_resize(Box::new({
716 let mut cx = cx.to_async();
717 move |_, _| {
718 handle
719 .update(&mut cx, |_, cx| cx.bounds_changed())
720 .log_err();
721 }
722 }));
723 platform_window.on_moved(Box::new({
724 let mut cx = cx.to_async();
725 move || {
726 handle
727 .update(&mut cx, |_, cx| cx.bounds_changed())
728 .log_err();
729 }
730 }));
731 platform_window.on_appearance_changed(Box::new({
732 let mut cx = cx.to_async();
733 move || {
734 handle
735 .update(&mut cx, |_, cx| cx.appearance_changed())
736 .log_err();
737 }
738 }));
739 platform_window.on_active_status_change(Box::new({
740 let mut cx = cx.to_async();
741 move |active| {
742 handle
743 .update(&mut cx, |_, cx| {
744 cx.window.active.set(active);
745 cx.window
746 .activation_observers
747 .clone()
748 .retain(&(), |callback| callback(cx));
749 cx.refresh();
750 })
751 .log_err();
752 }
753 }));
754
755 platform_window.on_input({
756 let mut cx = cx.to_async();
757 Box::new(move |event| {
758 handle
759 .update(&mut cx, |_, cx| cx.dispatch_event(event))
760 .log_err()
761 .unwrap_or(DispatchEventResult::default())
762 })
763 });
764
765 if let Some(app_id) = app_id {
766 platform_window.set_app_id(&app_id);
767 }
768
769 Ok(Window {
770 handle,
771 removed: false,
772 platform_window,
773 display_id,
774 sprite_atlas,
775 text_system,
776 rem_size: px(16.),
777 rem_size_override_stack: SmallVec::new(),
778 viewport_size: content_size,
779 layout_engine: Some(TaffyLayoutEngine::new()),
780 root_view: None,
781 element_id_stack: SmallVec::default(),
782 text_style_stack: Vec::new(),
783 element_offset_stack: Vec::new(),
784 content_mask_stack: Vec::new(),
785 requested_autoscroll: None,
786 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
787 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
788 next_frame_callbacks,
789 next_hitbox_id: HitboxId::default(),
790 next_tooltip_id: TooltipId::default(),
791 tooltip_bounds: None,
792 dirty_views: FxHashSet::default(),
793 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
794 focus_listeners: SubscriberSet::new(),
795 focus_lost_listeners: SubscriberSet::new(),
796 default_prevented: true,
797 mouse_position,
798 mouse_hit_test: HitTest::default(),
799 modifiers,
800 scale_factor,
801 bounds_observers: SubscriberSet::new(),
802 appearance,
803 appearance_observers: SubscriberSet::new(),
804 active,
805 dirty,
806 needs_present,
807 last_input_timestamp,
808 refreshing: false,
809 draw_phase: DrawPhase::None,
810 activation_observers: SubscriberSet::new(),
811 focus: None,
812 focus_enabled: true,
813 pending_input: None,
814 pending_input_observers: SubscriberSet::new(),
815 prompt: None,
816 })
817 }
818 fn new_focus_listener(
819 &mut self,
820 value: AnyWindowFocusListener,
821 ) -> (Subscription, impl FnOnce()) {
822 self.focus_listeners.insert((), value)
823 }
824}
825
826#[derive(Clone, Debug, Default, PartialEq, Eq)]
827pub(crate) struct DispatchEventResult {
828 pub propagate: bool,
829 pub default_prevented: bool,
830}
831
832/// Indicates which region of the window is visible. Content falling outside of this mask will not be
833/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
834/// to leave room to support more complex shapes in the future.
835#[derive(Clone, Debug, Default, PartialEq, Eq)]
836#[repr(C)]
837pub struct ContentMask<P: Clone + Default + Debug> {
838 /// The bounds
839 pub bounds: Bounds<P>,
840}
841
842impl ContentMask<Pixels> {
843 /// Scale the content mask's pixel units by the given scaling factor.
844 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
845 ContentMask {
846 bounds: self.bounds.scale(factor),
847 }
848 }
849
850 /// Intersect the content mask with the given content mask.
851 pub fn intersect(&self, other: &Self) -> Self {
852 let bounds = self.bounds.intersect(&other.bounds);
853 ContentMask { bounds }
854 }
855}
856
857/// Provides access to application state in the context of a single window. Derefs
858/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
859/// an [`AppContext`] and call any [`AppContext`] methods.
860pub struct WindowContext<'a> {
861 pub(crate) app: &'a mut AppContext,
862 pub(crate) window: &'a mut Window,
863}
864
865impl<'a> WindowContext<'a> {
866 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
867 Self { app, window }
868 }
869
870 /// Obtain a handle to the window that belongs to this context.
871 pub fn window_handle(&self) -> AnyWindowHandle {
872 self.window.handle
873 }
874
875 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
876 pub fn refresh(&mut self) {
877 if self.window.draw_phase == DrawPhase::None {
878 self.window.refreshing = true;
879 self.window.dirty.set(true);
880 }
881 }
882
883 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
884 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
885 pub fn notify(&mut self, view_id: EntityId) {
886 for view_id in self
887 .window
888 .rendered_frame
889 .dispatch_tree
890 .view_path(view_id)
891 .into_iter()
892 .rev()
893 {
894 if !self.window.dirty_views.insert(view_id) {
895 break;
896 }
897 }
898
899 if self.window.draw_phase == DrawPhase::None {
900 self.window.dirty.set(true);
901 self.app.push_effect(Effect::Notify { emitter: view_id });
902 }
903 }
904
905 /// Close this window.
906 pub fn remove_window(&mut self) {
907 self.window.removed = true;
908 }
909
910 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
911 /// for elements rendered within this window.
912 pub fn focus_handle(&mut self) -> FocusHandle {
913 FocusHandle::new(&self.window.focus_handles)
914 }
915
916 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
917 pub fn focused(&self) -> Option<FocusHandle> {
918 self.window
919 .focus
920 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
921 }
922
923 /// Move focus to the element associated with the given [`FocusHandle`].
924 pub fn focus(&mut self, handle: &FocusHandle) {
925 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
926 return;
927 }
928
929 self.window.focus = Some(handle.id);
930 self.window
931 .rendered_frame
932 .dispatch_tree
933 .clear_pending_keystrokes();
934 self.refresh();
935 }
936
937 /// Remove focus from all elements within this context's window.
938 pub fn blur(&mut self) {
939 if !self.window.focus_enabled {
940 return;
941 }
942
943 self.window.focus = None;
944 self.refresh();
945 }
946
947 /// Blur the window and don't allow anything in it to be focused again.
948 pub fn disable_focus(&mut self) {
949 self.blur();
950 self.window.focus_enabled = false;
951 }
952
953 /// Accessor for the text system.
954 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
955 &self.window.text_system
956 }
957
958 /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
959 pub fn text_style(&self) -> TextStyle {
960 let mut style = TextStyle::default();
961 for refinement in &self.window.text_style_stack {
962 style.refine(refinement);
963 }
964 style
965 }
966
967 /// Check if the platform window is maximized
968 /// On some platforms (namely Windows) this is different than the bounds being the size of the display
969 pub fn is_maximized(&self) -> bool {
970 self.window.platform_window.is_maximized()
971 }
972
973 /// Return the `WindowBounds` to indicate that how a window should be opened
974 /// after it has been closed
975 pub fn window_bounds(&self) -> WindowBounds {
976 self.window.platform_window.window_bounds()
977 }
978
979 /// Dispatch the given action on the currently focused element.
980 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
981 let focus_handle = self.focused();
982
983 let window = self.window.handle;
984 self.app.defer(move |cx| {
985 window
986 .update(cx, |_, cx| {
987 let node_id = focus_handle
988 .and_then(|handle| {
989 cx.window
990 .rendered_frame
991 .dispatch_tree
992 .focusable_node_id(handle.id)
993 })
994 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
995
996 cx.dispatch_action_on_node(node_id, action.as_ref());
997 })
998 .log_err();
999 })
1000 }
1001
1002 pub(crate) fn dispatch_keystroke_observers(
1003 &mut self,
1004 event: &dyn Any,
1005 action: Option<Box<dyn Action>>,
1006 ) {
1007 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1008 return;
1009 };
1010
1011 self.keystroke_observers
1012 .clone()
1013 .retain(&(), move |callback| {
1014 (callback)(
1015 &KeystrokeEvent {
1016 keystroke: key_down_event.keystroke.clone(),
1017 action: action.as_ref().map(|action| action.boxed_clone()),
1018 },
1019 self,
1020 );
1021 true
1022 });
1023 }
1024
1025 pub(crate) fn clear_pending_keystrokes(&mut self) {
1026 self.window
1027 .rendered_frame
1028 .dispatch_tree
1029 .clear_pending_keystrokes();
1030 self.window
1031 .next_frame
1032 .dispatch_tree
1033 .clear_pending_keystrokes();
1034 }
1035
1036 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1037 /// that are currently on the stack to be returned to the app.
1038 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
1039 let handle = self.window.handle;
1040 self.app.defer(move |cx| {
1041 handle.update(cx, |_, cx| f(cx)).ok();
1042 });
1043 }
1044
1045 /// Subscribe to events emitted by a model or view.
1046 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1047 /// The callback will be invoked a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a window context for the current window.
1048 pub fn observe<E, T>(
1049 &mut self,
1050 entity: &E,
1051 mut on_notify: impl FnMut(E, &mut WindowContext<'_>) + 'static,
1052 ) -> Subscription
1053 where
1054 E: Entity<T>,
1055 {
1056 let entity_id = entity.entity_id();
1057 let entity = entity.downgrade();
1058 let window_handle = self.window.handle;
1059 self.app.new_observer(
1060 entity_id,
1061 Box::new(move |cx| {
1062 window_handle
1063 .update(cx, |_, cx| {
1064 if let Some(handle) = E::upgrade_from(&entity) {
1065 on_notify(handle, cx);
1066 true
1067 } else {
1068 false
1069 }
1070 })
1071 .unwrap_or(false)
1072 }),
1073 )
1074 }
1075
1076 /// Subscribe to events emitted by a model or view.
1077 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1078 /// The callback will be invoked a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a window context for the current window.
1079 pub fn subscribe<Emitter, E, Evt>(
1080 &mut self,
1081 entity: &E,
1082 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
1083 ) -> Subscription
1084 where
1085 Emitter: EventEmitter<Evt>,
1086 E: Entity<Emitter>,
1087 Evt: 'static,
1088 {
1089 let entity_id = entity.entity_id();
1090 let entity = entity.downgrade();
1091 let window_handle = self.window.handle;
1092 self.app.new_subscription(
1093 entity_id,
1094 (
1095 TypeId::of::<Evt>(),
1096 Box::new(move |event, cx| {
1097 window_handle
1098 .update(cx, |_, cx| {
1099 if let Some(handle) = E::upgrade_from(&entity) {
1100 let event = event.downcast_ref().expect("invalid event type");
1101 on_event(handle, event, cx);
1102 true
1103 } else {
1104 false
1105 }
1106 })
1107 .unwrap_or(false)
1108 }),
1109 ),
1110 )
1111 }
1112
1113 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1114 /// await points in async code.
1115 pub fn to_async(&self) -> AsyncWindowContext {
1116 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
1117 }
1118
1119 /// Schedule the given closure to be run directly after the current frame is rendered.
1120 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
1121 RefCell::borrow_mut(&self.window.next_frame_callbacks).push(Box::new(callback));
1122 }
1123
1124 /// Spawn the future returned by the given closure on the application thread pool.
1125 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1126 /// use within your future.
1127 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
1128 where
1129 R: 'static,
1130 Fut: Future<Output = R> + 'static,
1131 {
1132 self.app
1133 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
1134 }
1135
1136 fn bounds_changed(&mut self) {
1137 self.window.scale_factor = self.window.platform_window.scale_factor();
1138 self.window.viewport_size = self.window.platform_window.content_size();
1139 self.window.display_id = self
1140 .window
1141 .platform_window
1142 .display()
1143 .map(|display| display.id());
1144
1145 self.refresh();
1146
1147 self.window
1148 .bounds_observers
1149 .clone()
1150 .retain(&(), |callback| callback(self));
1151 }
1152
1153 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1154 pub fn bounds(&self) -> Bounds<Pixels> {
1155 self.window.platform_window.bounds()
1156 }
1157
1158 /// Returns whether or not the window is currently fullscreen
1159 pub fn is_fullscreen(&self) -> bool {
1160 self.window.platform_window.is_fullscreen()
1161 }
1162
1163 pub(crate) fn appearance_changed(&mut self) {
1164 self.window.appearance = self.window.platform_window.appearance();
1165
1166 self.window
1167 .appearance_observers
1168 .clone()
1169 .retain(&(), |callback| callback(self));
1170 }
1171
1172 /// Returns the appearance of the current window.
1173 pub fn appearance(&self) -> WindowAppearance {
1174 self.window.appearance
1175 }
1176
1177 /// Returns the size of the drawable area within the window.
1178 pub fn viewport_size(&self) -> Size<Pixels> {
1179 self.window.viewport_size
1180 }
1181
1182 /// Returns whether this window is focused by the operating system (receiving key events).
1183 pub fn is_window_active(&self) -> bool {
1184 self.window.active.get()
1185 }
1186
1187 /// Toggle zoom on the window.
1188 pub fn zoom_window(&self) {
1189 self.window.platform_window.zoom();
1190 }
1191
1192 /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1193 pub fn show_window_menu(&self, position: Point<Pixels>) {
1194 self.window.platform_window.show_window_menu(position)
1195 }
1196
1197 /// Tells the compositor to take control of window movement (Wayland and X11)
1198 ///
1199 /// Events may not be received during a move operation.
1200 pub fn start_system_move(&self) {
1201 self.window.platform_window.start_system_move()
1202 }
1203
1204 /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1205 pub fn should_render_window_controls(&self) -> bool {
1206 self.window.platform_window.should_render_window_controls()
1207 }
1208
1209 /// Updates the window's title at the platform level.
1210 pub fn set_window_title(&mut self, title: &str) {
1211 self.window.platform_window.set_title(title);
1212 }
1213
1214 /// Sets the application identifier.
1215 pub fn set_app_id(&mut self, app_id: &str) {
1216 self.window.platform_window.set_app_id(app_id);
1217 }
1218
1219 /// Sets the window background appearance.
1220 pub fn set_background_appearance(&mut self, background_appearance: WindowBackgroundAppearance) {
1221 self.window
1222 .platform_window
1223 .set_background_appearance(background_appearance);
1224 }
1225
1226 /// Mark the window as dirty at the platform level.
1227 pub fn set_window_edited(&mut self, edited: bool) {
1228 self.window.platform_window.set_edited(edited);
1229 }
1230
1231 /// Determine the display on which the window is visible.
1232 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
1233 self.platform
1234 .displays()
1235 .into_iter()
1236 .find(|display| Some(display.id()) == self.window.display_id)
1237 }
1238
1239 /// Show the platform character palette.
1240 pub fn show_character_palette(&self) {
1241 self.window.platform_window.show_character_palette();
1242 }
1243
1244 /// The scale factor of the display associated with the window. For example, it could
1245 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
1246 /// be rendered as two pixels on screen.
1247 pub fn scale_factor(&self) -> f32 {
1248 self.window.scale_factor
1249 }
1250
1251 /// The size of an em for the base font of the application. Adjusting this value allows the
1252 /// UI to scale, just like zooming a web page.
1253 pub fn rem_size(&self) -> Pixels {
1254 self.window
1255 .rem_size_override_stack
1256 .last()
1257 .copied()
1258 .unwrap_or(self.window.rem_size)
1259 }
1260
1261 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
1262 /// UI to scale, just like zooming a web page.
1263 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
1264 self.window.rem_size = rem_size.into();
1265 }
1266
1267 /// Executes the provided function with the specified rem size.
1268 ///
1269 /// This method must only be called as part of element drawing.
1270 pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
1271 where
1272 F: FnOnce(&mut Self) -> R,
1273 {
1274 debug_assert!(
1275 matches!(
1276 self.window.draw_phase,
1277 DrawPhase::Prepaint | DrawPhase::Paint
1278 ),
1279 "this method can only be called during request_layout, prepaint, or paint"
1280 );
1281
1282 if let Some(rem_size) = rem_size {
1283 self.window.rem_size_override_stack.push(rem_size.into());
1284 let result = f(self);
1285 self.window.rem_size_override_stack.pop();
1286 result
1287 } else {
1288 f(self)
1289 }
1290 }
1291
1292 /// The line height associated with the current text style.
1293 pub fn line_height(&self) -> Pixels {
1294 let rem_size = self.rem_size();
1295 let text_style = self.text_style();
1296 text_style
1297 .line_height
1298 .to_pixels(text_style.font_size, rem_size)
1299 }
1300
1301 /// Call to prevent the default action of an event. Currently only used to prevent
1302 /// parent elements from becoming focused on mouse down.
1303 pub fn prevent_default(&mut self) {
1304 self.window.default_prevented = true;
1305 }
1306
1307 /// Obtain whether default has been prevented for the event currently being dispatched.
1308 pub fn default_prevented(&self) -> bool {
1309 self.window.default_prevented
1310 }
1311
1312 /// Determine whether the given action is available along the dispatch path to the currently focused element.
1313 pub fn is_action_available(&self, action: &dyn Action) -> bool {
1314 let target = self
1315 .focused()
1316 .and_then(|focused_handle| {
1317 self.window
1318 .rendered_frame
1319 .dispatch_tree
1320 .focusable_node_id(focused_handle.id)
1321 })
1322 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1323 self.window
1324 .rendered_frame
1325 .dispatch_tree
1326 .is_action_available(action, target)
1327 }
1328
1329 /// The position of the mouse relative to the window.
1330 pub fn mouse_position(&self) -> Point<Pixels> {
1331 self.window.mouse_position
1332 }
1333
1334 /// The current state of the keyboard's modifiers
1335 pub fn modifiers(&self) -> Modifiers {
1336 self.window.modifiers
1337 }
1338
1339 fn complete_frame(&self) {
1340 self.window.platform_window.completed_frame();
1341 }
1342
1343 /// Produces a new frame and assigns it to `rendered_frame`. To actually show
1344 /// the contents of the new [Scene], use [present].
1345 #[profiling::function]
1346 pub fn draw(&mut self) {
1347 self.window.dirty.set(false);
1348 self.window.requested_autoscroll = None;
1349
1350 // Restore the previously-used input handler.
1351 if let Some(input_handler) = self.window.platform_window.take_input_handler() {
1352 self.window
1353 .rendered_frame
1354 .input_handlers
1355 .push(Some(input_handler));
1356 }
1357
1358 self.draw_roots();
1359 self.window.dirty_views.clear();
1360
1361 self.window
1362 .next_frame
1363 .dispatch_tree
1364 .preserve_pending_keystrokes(
1365 &mut self.window.rendered_frame.dispatch_tree,
1366 self.window.focus,
1367 );
1368 self.window.next_frame.focus = self.window.focus;
1369 self.window.next_frame.window_active = self.window.active.get();
1370
1371 // Register requested input handler with the platform window.
1372 if let Some(input_handler) = self.window.next_frame.input_handlers.pop() {
1373 self.window
1374 .platform_window
1375 .set_input_handler(input_handler.unwrap());
1376 }
1377
1378 self.window.layout_engine.as_mut().unwrap().clear();
1379 self.text_system().finish_frame();
1380 self.window
1381 .next_frame
1382 .finish(&mut self.window.rendered_frame);
1383 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1384 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1385 if percentage >= 80. {
1386 log::warn!("elevated element arena occupation: {}.", percentage);
1387 }
1388 element_arena.clear();
1389 });
1390
1391 self.window.draw_phase = DrawPhase::Focus;
1392 let previous_focus_path = self.window.rendered_frame.focus_path();
1393 let previous_window_active = self.window.rendered_frame.window_active;
1394 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1395 self.window.next_frame.clear();
1396 let current_focus_path = self.window.rendered_frame.focus_path();
1397 let current_window_active = self.window.rendered_frame.window_active;
1398
1399 if previous_focus_path != current_focus_path
1400 || previous_window_active != current_window_active
1401 {
1402 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1403 self.window
1404 .focus_lost_listeners
1405 .clone()
1406 .retain(&(), |listener| listener(self));
1407 }
1408
1409 let event = WindowFocusEvent {
1410 previous_focus_path: if previous_window_active {
1411 previous_focus_path
1412 } else {
1413 Default::default()
1414 },
1415 current_focus_path: if current_window_active {
1416 current_focus_path
1417 } else {
1418 Default::default()
1419 },
1420 };
1421 self.window
1422 .focus_listeners
1423 .clone()
1424 .retain(&(), |listener| listener(&event, self));
1425 }
1426
1427 self.reset_cursor_style();
1428 self.window.refreshing = false;
1429 self.window.draw_phase = DrawPhase::None;
1430 self.window.needs_present.set(true);
1431 }
1432
1433 #[profiling::function]
1434 fn present(&self) {
1435 self.window
1436 .platform_window
1437 .draw(&self.window.rendered_frame.scene);
1438 self.window.needs_present.set(false);
1439 profiling::finish_frame!();
1440 }
1441
1442 fn draw_roots(&mut self) {
1443 self.window.draw_phase = DrawPhase::Prepaint;
1444 self.window.tooltip_bounds.take();
1445
1446 // Layout all root elements.
1447 let mut root_element = self.window.root_view.as_ref().unwrap().clone().into_any();
1448 root_element.prepaint_as_root(Point::default(), self.window.viewport_size.into(), self);
1449
1450 let mut sorted_deferred_draws =
1451 (0..self.window.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
1452 sorted_deferred_draws.sort_by_key(|ix| self.window.next_frame.deferred_draws[*ix].priority);
1453 self.prepaint_deferred_draws(&sorted_deferred_draws);
1454
1455 let mut prompt_element = None;
1456 let mut active_drag_element = None;
1457 let mut tooltip_element = None;
1458 if let Some(prompt) = self.window.prompt.take() {
1459 let mut element = prompt.view.any_view().into_any();
1460 element.prepaint_as_root(Point::default(), self.window.viewport_size.into(), self);
1461 prompt_element = Some(element);
1462 self.window.prompt = Some(prompt);
1463 } else if let Some(active_drag) = self.app.active_drag.take() {
1464 let mut element = active_drag.view.clone().into_any();
1465 let offset = self.mouse_position() - active_drag.cursor_offset;
1466 element.prepaint_as_root(offset, AvailableSpace::min_size(), self);
1467 active_drag_element = Some(element);
1468 self.app.active_drag = Some(active_drag);
1469 } else {
1470 tooltip_element = self.prepaint_tooltip();
1471 }
1472
1473 self.window.mouse_hit_test = self.window.next_frame.hit_test(self.window.mouse_position);
1474
1475 // Now actually paint the elements.
1476 self.window.draw_phase = DrawPhase::Paint;
1477 root_element.paint(self);
1478
1479 self.paint_deferred_draws(&sorted_deferred_draws);
1480
1481 if let Some(mut prompt_element) = prompt_element {
1482 prompt_element.paint(self)
1483 } else if let Some(mut drag_element) = active_drag_element {
1484 drag_element.paint(self);
1485 } else if let Some(mut tooltip_element) = tooltip_element {
1486 tooltip_element.paint(self);
1487 }
1488 }
1489
1490 fn prepaint_tooltip(&mut self) -> Option<AnyElement> {
1491 let tooltip_request = self.window.next_frame.tooltip_requests.last().cloned()?;
1492 let tooltip_request = tooltip_request.unwrap();
1493 let mut element = tooltip_request.tooltip.view.clone().into_any();
1494 let mouse_position = tooltip_request.tooltip.mouse_position;
1495 let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self);
1496
1497 let mut tooltip_bounds = Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
1498 let window_bounds = Bounds {
1499 origin: Point::default(),
1500 size: self.viewport_size(),
1501 };
1502
1503 if tooltip_bounds.right() > window_bounds.right() {
1504 let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
1505 if new_x >= Pixels::ZERO {
1506 tooltip_bounds.origin.x = new_x;
1507 } else {
1508 tooltip_bounds.origin.x = cmp::max(
1509 Pixels::ZERO,
1510 tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
1511 );
1512 }
1513 }
1514
1515 if tooltip_bounds.bottom() > window_bounds.bottom() {
1516 let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
1517 if new_y >= Pixels::ZERO {
1518 tooltip_bounds.origin.y = new_y;
1519 } else {
1520 tooltip_bounds.origin.y = cmp::max(
1521 Pixels::ZERO,
1522 tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
1523 );
1524 }
1525 }
1526
1527 self.with_absolute_element_offset(tooltip_bounds.origin, |cx| element.prepaint(cx));
1528
1529 self.window.tooltip_bounds = Some(TooltipBounds {
1530 id: tooltip_request.id,
1531 bounds: tooltip_bounds,
1532 });
1533 Some(element)
1534 }
1535
1536 fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize]) {
1537 assert_eq!(self.window.element_id_stack.len(), 0);
1538
1539 let mut deferred_draws = mem::take(&mut self.window.next_frame.deferred_draws);
1540 for deferred_draw_ix in deferred_draw_indices {
1541 let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1542 self.window
1543 .element_id_stack
1544 .clone_from(&deferred_draw.element_id_stack);
1545 self.window
1546 .text_style_stack
1547 .clone_from(&deferred_draw.text_style_stack);
1548 self.window
1549 .next_frame
1550 .dispatch_tree
1551 .set_active_node(deferred_draw.parent_node);
1552
1553 let prepaint_start = self.prepaint_index();
1554 if let Some(element) = deferred_draw.element.as_mut() {
1555 self.with_absolute_element_offset(deferred_draw.absolute_offset, |cx| {
1556 element.prepaint(cx)
1557 });
1558 } else {
1559 self.reuse_prepaint(deferred_draw.prepaint_range.clone());
1560 }
1561 let prepaint_end = self.prepaint_index();
1562 deferred_draw.prepaint_range = prepaint_start..prepaint_end;
1563 }
1564 assert_eq!(
1565 self.window.next_frame.deferred_draws.len(),
1566 0,
1567 "cannot call defer_draw during deferred drawing"
1568 );
1569 self.window.next_frame.deferred_draws = deferred_draws;
1570 self.window.element_id_stack.clear();
1571 self.window.text_style_stack.clear();
1572 }
1573
1574 fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize]) {
1575 assert_eq!(self.window.element_id_stack.len(), 0);
1576
1577 let mut deferred_draws = mem::take(&mut self.window.next_frame.deferred_draws);
1578 for deferred_draw_ix in deferred_draw_indices {
1579 let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1580 self.window
1581 .element_id_stack
1582 .clone_from(&deferred_draw.element_id_stack);
1583 self.window
1584 .next_frame
1585 .dispatch_tree
1586 .set_active_node(deferred_draw.parent_node);
1587
1588 let paint_start = self.paint_index();
1589 if let Some(element) = deferred_draw.element.as_mut() {
1590 element.paint(self);
1591 } else {
1592 self.reuse_paint(deferred_draw.paint_range.clone());
1593 }
1594 let paint_end = self.paint_index();
1595 deferred_draw.paint_range = paint_start..paint_end;
1596 }
1597 self.window.next_frame.deferred_draws = deferred_draws;
1598 self.window.element_id_stack.clear();
1599 }
1600
1601 pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
1602 PrepaintStateIndex {
1603 hitboxes_index: self.window.next_frame.hitboxes.len(),
1604 tooltips_index: self.window.next_frame.tooltip_requests.len(),
1605 deferred_draws_index: self.window.next_frame.deferred_draws.len(),
1606 dispatch_tree_index: self.window.next_frame.dispatch_tree.len(),
1607 accessed_element_states_index: self.window.next_frame.accessed_element_states.len(),
1608 line_layout_index: self.window.text_system.layout_index(),
1609 }
1610 }
1611
1612 pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
1613 let window = &mut self.window;
1614 window.next_frame.hitboxes.extend(
1615 window.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
1616 .iter()
1617 .cloned(),
1618 );
1619 window.next_frame.tooltip_requests.extend(
1620 window.rendered_frame.tooltip_requests
1621 [range.start.tooltips_index..range.end.tooltips_index]
1622 .iter_mut()
1623 .map(|request| request.take()),
1624 );
1625 window.next_frame.accessed_element_states.extend(
1626 window.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
1627 ..range.end.accessed_element_states_index]
1628 .iter()
1629 .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
1630 );
1631 window
1632 .text_system
1633 .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
1634
1635 let reused_subtree = window.next_frame.dispatch_tree.reuse_subtree(
1636 range.start.dispatch_tree_index..range.end.dispatch_tree_index,
1637 &mut window.rendered_frame.dispatch_tree,
1638 );
1639 window.next_frame.deferred_draws.extend(
1640 window.rendered_frame.deferred_draws
1641 [range.start.deferred_draws_index..range.end.deferred_draws_index]
1642 .iter()
1643 .map(|deferred_draw| DeferredDraw {
1644 parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
1645 element_id_stack: deferred_draw.element_id_stack.clone(),
1646 text_style_stack: deferred_draw.text_style_stack.clone(),
1647 priority: deferred_draw.priority,
1648 element: None,
1649 absolute_offset: deferred_draw.absolute_offset,
1650 prepaint_range: deferred_draw.prepaint_range.clone(),
1651 paint_range: deferred_draw.paint_range.clone(),
1652 }),
1653 );
1654 }
1655
1656 pub(crate) fn paint_index(&self) -> PaintIndex {
1657 PaintIndex {
1658 scene_index: self.window.next_frame.scene.len(),
1659 mouse_listeners_index: self.window.next_frame.mouse_listeners.len(),
1660 input_handlers_index: self.window.next_frame.input_handlers.len(),
1661 cursor_styles_index: self.window.next_frame.cursor_styles.len(),
1662 accessed_element_states_index: self.window.next_frame.accessed_element_states.len(),
1663 line_layout_index: self.window.text_system.layout_index(),
1664 }
1665 }
1666
1667 pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
1668 let window = &mut self.window;
1669
1670 window.next_frame.cursor_styles.extend(
1671 window.rendered_frame.cursor_styles
1672 [range.start.cursor_styles_index..range.end.cursor_styles_index]
1673 .iter()
1674 .cloned(),
1675 );
1676 window.next_frame.input_handlers.extend(
1677 window.rendered_frame.input_handlers
1678 [range.start.input_handlers_index..range.end.input_handlers_index]
1679 .iter_mut()
1680 .map(|handler| handler.take()),
1681 );
1682 window.next_frame.mouse_listeners.extend(
1683 window.rendered_frame.mouse_listeners
1684 [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
1685 .iter_mut()
1686 .map(|listener| listener.take()),
1687 );
1688 window.next_frame.accessed_element_states.extend(
1689 window.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
1690 ..range.end.accessed_element_states_index]
1691 .iter()
1692 .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
1693 );
1694 window
1695 .text_system
1696 .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
1697 window.next_frame.scene.replay(
1698 range.start.scene_index..range.end.scene_index,
1699 &window.rendered_frame.scene,
1700 );
1701 }
1702
1703 /// Push a text style onto the stack, and call a function with that style active.
1704 /// Use [`AppContext::text_style`] to get the current, combined text style. This method
1705 /// should only be called as part of element drawing.
1706 pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
1707 where
1708 F: FnOnce(&mut Self) -> R,
1709 {
1710 debug_assert!(
1711 matches!(
1712 self.window.draw_phase,
1713 DrawPhase::Prepaint | DrawPhase::Paint
1714 ),
1715 "this method can only be called during request_layout, prepaint, or paint"
1716 );
1717 if let Some(style) = style {
1718 self.window.text_style_stack.push(style);
1719 let result = f(self);
1720 self.window.text_style_stack.pop();
1721 result
1722 } else {
1723 f(self)
1724 }
1725 }
1726
1727 /// Updates the cursor style at the platform level. This method should only be called
1728 /// during the prepaint phase of element drawing.
1729 pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
1730 debug_assert_eq!(
1731 self.window.draw_phase,
1732 DrawPhase::Paint,
1733 "this method can only be called during paint"
1734 );
1735 self.window
1736 .next_frame
1737 .cursor_styles
1738 .push(CursorStyleRequest {
1739 hitbox_id: hitbox.id,
1740 style,
1741 });
1742 }
1743
1744 /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
1745 /// during the paint phase of element drawing.
1746 pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
1747 debug_assert_eq!(
1748 self.window.draw_phase,
1749 DrawPhase::Prepaint,
1750 "this method can only be called during prepaint"
1751 );
1752 let id = TooltipId(post_inc(&mut self.window.next_tooltip_id.0));
1753 self.window
1754 .next_frame
1755 .tooltip_requests
1756 .push(Some(TooltipRequest { id, tooltip }));
1757 id
1758 }
1759
1760 /// Invoke the given function with the given content mask after intersecting it
1761 /// with the current mask. This method should only be called during element drawing.
1762 pub fn with_content_mask<R>(
1763 &mut self,
1764 mask: Option<ContentMask<Pixels>>,
1765 f: impl FnOnce(&mut Self) -> R,
1766 ) -> R {
1767 debug_assert!(
1768 matches!(
1769 self.window.draw_phase,
1770 DrawPhase::Prepaint | DrawPhase::Paint
1771 ),
1772 "this method can only be called during request_layout, prepaint, or paint"
1773 );
1774 if let Some(mask) = mask {
1775 let mask = mask.intersect(&self.content_mask());
1776 self.window_mut().content_mask_stack.push(mask);
1777 let result = f(self);
1778 self.window_mut().content_mask_stack.pop();
1779 result
1780 } else {
1781 f(self)
1782 }
1783 }
1784
1785 /// Updates the global element offset relative to the current offset. This is used to implement
1786 /// scrolling. This method should only be called during the prepaint phase of element drawing.
1787 pub fn with_element_offset<R>(
1788 &mut self,
1789 offset: Point<Pixels>,
1790 f: impl FnOnce(&mut Self) -> R,
1791 ) -> R {
1792 debug_assert_eq!(
1793 self.window.draw_phase,
1794 DrawPhase::Prepaint,
1795 "this method can only be called during request_layout, or prepaint"
1796 );
1797
1798 if offset.is_zero() {
1799 return f(self);
1800 };
1801
1802 let abs_offset = self.element_offset() + offset;
1803 self.with_absolute_element_offset(abs_offset, f)
1804 }
1805
1806 /// Updates the global element offset based on the given offset. This is used to implement
1807 /// drag handles and other manual painting of elements. This method should only be called during
1808 /// the prepaint phase of element drawing.
1809 pub fn with_absolute_element_offset<R>(
1810 &mut self,
1811 offset: Point<Pixels>,
1812 f: impl FnOnce(&mut Self) -> R,
1813 ) -> R {
1814 debug_assert_eq!(
1815 self.window.draw_phase,
1816 DrawPhase::Prepaint,
1817 "this method can only be called during request_layout, or prepaint"
1818 );
1819 self.window_mut().element_offset_stack.push(offset);
1820 let result = f(self);
1821 self.window_mut().element_offset_stack.pop();
1822 result
1823 }
1824
1825 /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
1826 /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
1827 /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
1828 /// element offset and prepaint again. See [`List`] for an example. This method should only be
1829 /// called during the prepaint phase of element drawing.
1830 pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
1831 debug_assert_eq!(
1832 self.window.draw_phase,
1833 DrawPhase::Prepaint,
1834 "this method can only be called during prepaint"
1835 );
1836 let index = self.prepaint_index();
1837 let result = f(self);
1838 if result.is_err() {
1839 self.window
1840 .next_frame
1841 .hitboxes
1842 .truncate(index.hitboxes_index);
1843 self.window
1844 .next_frame
1845 .tooltip_requests
1846 .truncate(index.tooltips_index);
1847 self.window
1848 .next_frame
1849 .deferred_draws
1850 .truncate(index.deferred_draws_index);
1851 self.window
1852 .next_frame
1853 .dispatch_tree
1854 .truncate(index.dispatch_tree_index);
1855 self.window
1856 .next_frame
1857 .accessed_element_states
1858 .truncate(index.accessed_element_states_index);
1859 self.window
1860 .text_system
1861 .truncate_layouts(index.line_layout_index);
1862 }
1863 result
1864 }
1865
1866 /// When you call this method during [`prepaint`], containing elements will attempt to
1867 /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
1868 /// [`prepaint`] again with a new set of bounds. See [`List`] for an example of an element
1869 /// that supports this method being called on the elements it contains. This method should only be
1870 /// called during the prepaint phase of element drawing.
1871 pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
1872 debug_assert_eq!(
1873 self.window.draw_phase,
1874 DrawPhase::Prepaint,
1875 "this method can only be called during prepaint"
1876 );
1877 self.window.requested_autoscroll = Some(bounds);
1878 }
1879
1880 /// This method can be called from a containing element such as [`List`] to support the autoscroll behavior
1881 /// described in [`request_autoscroll`].
1882 pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
1883 debug_assert_eq!(
1884 self.window.draw_phase,
1885 DrawPhase::Prepaint,
1886 "this method can only be called during prepaint"
1887 );
1888 self.window.requested_autoscroll.take()
1889 }
1890
1891 /// Remove an asset from GPUI's cache
1892 pub fn remove_cached_asset<A: Asset + 'static>(
1893 &mut self,
1894 source: &A::Source,
1895 ) -> Option<A::Output> {
1896 self.asset_cache.remove::<A>(source)
1897 }
1898
1899 /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
1900 /// Your view will be re-drawn once the asset has finished loading.
1901 ///
1902 /// Note that the multiple calls to this method will only result in one `Asset::load` call.
1903 /// The results of that call will be cached, and returned on subsequent uses of this API.
1904 ///
1905 /// Use [Self::remove_cached_asset] to reload your asset.
1906 pub fn use_cached_asset<A: Asset + 'static>(
1907 &mut self,
1908 source: &A::Source,
1909 ) -> Option<A::Output> {
1910 self.asset_cache.get::<A>(source).or_else(|| {
1911 if let Some(asset) = self.use_asset::<A>(source) {
1912 self.asset_cache
1913 .insert::<A>(source.to_owned(), asset.clone());
1914 Some(asset)
1915 } else {
1916 None
1917 }
1918 })
1919 }
1920
1921 /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
1922 /// Your view will be re-drawn once the asset has finished loading.
1923 ///
1924 /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
1925 /// time.
1926 ///
1927 /// This asset will not be cached by default, see [Self::use_cached_asset]
1928 pub fn use_asset<A: Asset + 'static>(&mut self, source: &A::Source) -> Option<A::Output> {
1929 let asset_id = (TypeId::of::<A>(), hash(source));
1930 let mut is_first = false;
1931 let task = self
1932 .loading_assets
1933 .remove(&asset_id)
1934 .map(|boxed_task| *boxed_task.downcast::<Shared<Task<A::Output>>>().unwrap())
1935 .unwrap_or_else(|| {
1936 is_first = true;
1937 let future = A::load(source.clone(), self);
1938 let task = self.background_executor().spawn(future).shared();
1939 task
1940 });
1941
1942 task.clone().now_or_never().or_else(|| {
1943 if is_first {
1944 let parent_id = self.parent_view_id();
1945 self.spawn({
1946 let task = task.clone();
1947 |mut cx| async move {
1948 task.await;
1949
1950 cx.on_next_frame(move |cx| {
1951 if let Some(parent_id) = parent_id {
1952 cx.notify(parent_id)
1953 } else {
1954 cx.refresh()
1955 }
1956 });
1957 }
1958 })
1959 .detach();
1960 }
1961
1962 self.loading_assets.insert(asset_id, Box::new(task));
1963
1964 None
1965 })
1966 }
1967
1968 /// Obtain the current element offset. This method should only be called during the
1969 /// prepaint phase of element drawing.
1970 pub fn element_offset(&self) -> Point<Pixels> {
1971 debug_assert_eq!(
1972 self.window.draw_phase,
1973 DrawPhase::Prepaint,
1974 "this method can only be called during prepaint"
1975 );
1976 self.window()
1977 .element_offset_stack
1978 .last()
1979 .copied()
1980 .unwrap_or_default()
1981 }
1982
1983 /// Obtain the current content mask. This method should only be called during element drawing.
1984 pub fn content_mask(&self) -> ContentMask<Pixels> {
1985 debug_assert!(
1986 matches!(
1987 self.window.draw_phase,
1988 DrawPhase::Prepaint | DrawPhase::Paint
1989 ),
1990 "this method can only be called during prepaint, or paint"
1991 );
1992 self.window()
1993 .content_mask_stack
1994 .last()
1995 .cloned()
1996 .unwrap_or_else(|| ContentMask {
1997 bounds: Bounds {
1998 origin: Point::default(),
1999 size: self.window().viewport_size,
2000 },
2001 })
2002 }
2003
2004 /// Provide elements in the called function with a new namespace in which their identiers must be unique.
2005 /// This can be used within a custom element to distinguish multiple sets of child elements.
2006 pub fn with_element_namespace<R>(
2007 &mut self,
2008 element_id: impl Into<ElementId>,
2009 f: impl FnOnce(&mut Self) -> R,
2010 ) -> R {
2011 self.window.element_id_stack.push(element_id.into());
2012 let result = f(self);
2013 self.window.element_id_stack.pop();
2014 result
2015 }
2016
2017 /// Updates or initializes state for an element with the given id that lives across multiple
2018 /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2019 /// to the given closure. The state returned by the closure will be stored so it can be referenced
2020 /// when drawing the next frame. This method should only be called as part of element drawing.
2021 pub fn with_element_state<S, R>(
2022 &mut self,
2023 global_id: &GlobalElementId,
2024 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2025 ) -> R
2026 where
2027 S: 'static,
2028 {
2029 debug_assert!(
2030 matches!(
2031 self.window.draw_phase,
2032 DrawPhase::Prepaint | DrawPhase::Paint
2033 ),
2034 "this method can only be called during request_layout, prepaint, or paint"
2035 );
2036
2037 let key = (GlobalElementId(global_id.0.clone()), TypeId::of::<S>());
2038 self.window
2039 .next_frame
2040 .accessed_element_states
2041 .push((GlobalElementId(key.0.clone()), TypeId::of::<S>()));
2042
2043 if let Some(any) = self
2044 .window
2045 .next_frame
2046 .element_states
2047 .remove(&key)
2048 .or_else(|| self.window.rendered_frame.element_states.remove(&key))
2049 {
2050 let ElementStateBox {
2051 inner,
2052 #[cfg(debug_assertions)]
2053 type_name,
2054 } = any;
2055 // Using the extra inner option to avoid needing to reallocate a new box.
2056 let mut state_box = inner
2057 .downcast::<Option<S>>()
2058 .map_err(|_| {
2059 #[cfg(debug_assertions)]
2060 {
2061 anyhow::anyhow!(
2062 "invalid element state type for id, requested {:?}, actual: {:?}",
2063 std::any::type_name::<S>(),
2064 type_name
2065 )
2066 }
2067
2068 #[cfg(not(debug_assertions))]
2069 {
2070 anyhow::anyhow!(
2071 "invalid element state type for id, requested {:?}",
2072 std::any::type_name::<S>(),
2073 )
2074 }
2075 })
2076 .unwrap();
2077
2078 let state = state_box.take().expect(
2079 "reentrant call to with_element_state for the same state type and element id",
2080 );
2081 let (result, state) = f(Some(state), self);
2082 state_box.replace(state);
2083 self.window.next_frame.element_states.insert(
2084 key,
2085 ElementStateBox {
2086 inner: state_box,
2087 #[cfg(debug_assertions)]
2088 type_name,
2089 },
2090 );
2091 result
2092 } else {
2093 let (result, state) = f(None, self);
2094 self.window.next_frame.element_states.insert(
2095 key,
2096 ElementStateBox {
2097 inner: Box::new(Some(state)),
2098 #[cfg(debug_assertions)]
2099 type_name: std::any::type_name::<S>(),
2100 },
2101 );
2102 result
2103 }
2104 }
2105
2106 /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2107 /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2108 /// when the element is guaranteed to have an id.
2109 pub fn with_optional_element_state<S, R>(
2110 &mut self,
2111 global_id: Option<&GlobalElementId>,
2112 f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2113 ) -> R
2114 where
2115 S: 'static,
2116 {
2117 debug_assert!(
2118 matches!(
2119 self.window.draw_phase,
2120 DrawPhase::Prepaint | DrawPhase::Paint
2121 ),
2122 "this method can only be called during request_layout, prepaint, or paint"
2123 );
2124
2125 if let Some(global_id) = global_id {
2126 self.with_element_state(global_id, |state, cx| {
2127 let (result, state) = f(Some(state), cx);
2128 let state =
2129 state.expect("you must return some state when you pass some element id");
2130 (result, state)
2131 })
2132 } else {
2133 let (result, state) = f(None, self);
2134 debug_assert!(
2135 state.is_none(),
2136 "you must not return an element state when passing None for the global id"
2137 );
2138 result
2139 }
2140 }
2141
2142 /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2143 /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2144 /// with higher values being drawn on top.
2145 ///
2146 /// This method should only be called as part of the prepaint phase of element drawing.
2147 pub fn defer_draw(
2148 &mut self,
2149 element: AnyElement,
2150 absolute_offset: Point<Pixels>,
2151 priority: usize,
2152 ) {
2153 let window = &mut self.window;
2154 debug_assert_eq!(
2155 window.draw_phase,
2156 DrawPhase::Prepaint,
2157 "this method can only be called during request_layout or prepaint"
2158 );
2159 let parent_node = window.next_frame.dispatch_tree.active_node_id().unwrap();
2160 window.next_frame.deferred_draws.push(DeferredDraw {
2161 parent_node,
2162 element_id_stack: window.element_id_stack.clone(),
2163 text_style_stack: window.text_style_stack.clone(),
2164 priority,
2165 element: Some(element),
2166 absolute_offset,
2167 prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2168 paint_range: PaintIndex::default()..PaintIndex::default(),
2169 });
2170 }
2171
2172 /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2173 /// of geometry that are non-overlapping and have the same draw order. This is typically used
2174 /// for performance reasons.
2175 ///
2176 /// This method should only be called as part of the paint phase of element drawing.
2177 pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2178 debug_assert_eq!(
2179 self.window.draw_phase,
2180 DrawPhase::Paint,
2181 "this method can only be called during paint"
2182 );
2183
2184 let scale_factor = self.scale_factor();
2185 let content_mask = self.content_mask();
2186 let clipped_bounds = bounds.intersect(&content_mask.bounds);
2187 if !clipped_bounds.is_empty() {
2188 self.window
2189 .next_frame
2190 .scene
2191 .push_layer(clipped_bounds.scale(scale_factor));
2192 }
2193
2194 let result = f(self);
2195
2196 if !clipped_bounds.is_empty() {
2197 self.window.next_frame.scene.pop_layer();
2198 }
2199
2200 result
2201 }
2202
2203 /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2204 ///
2205 /// This method should only be called as part of the paint phase of element drawing.
2206 pub fn paint_shadows(
2207 &mut self,
2208 bounds: Bounds<Pixels>,
2209 corner_radii: Corners<Pixels>,
2210 shadows: &[BoxShadow],
2211 ) {
2212 debug_assert_eq!(
2213 self.window.draw_phase,
2214 DrawPhase::Paint,
2215 "this method can only be called during paint"
2216 );
2217
2218 let scale_factor = self.scale_factor();
2219 let content_mask = self.content_mask();
2220 for shadow in shadows {
2221 let mut shadow_bounds = bounds;
2222 shadow_bounds.origin += shadow.offset;
2223 shadow_bounds.dilate(shadow.spread_radius);
2224 self.window.next_frame.scene.insert_primitive(Shadow {
2225 order: 0,
2226 blur_radius: shadow.blur_radius.scale(scale_factor),
2227 bounds: shadow_bounds.scale(scale_factor),
2228 content_mask: content_mask.scale(scale_factor),
2229 corner_radii: corner_radii.scale(scale_factor),
2230 color: shadow.color,
2231 });
2232 }
2233 }
2234
2235 /// Paint one or more quads into the scene for the next frame at the current stacking context.
2236 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2237 /// see [`fill`](crate::fill), [`outline`](crate::outline), and [`quad`](crate::quad) to construct this type.
2238 ///
2239 /// This method should only be called as part of the paint phase of element drawing.
2240 pub fn paint_quad(&mut self, quad: PaintQuad) {
2241 debug_assert_eq!(
2242 self.window.draw_phase,
2243 DrawPhase::Paint,
2244 "this method can only be called during paint"
2245 );
2246
2247 let scale_factor = self.scale_factor();
2248 let content_mask = self.content_mask();
2249 self.window.next_frame.scene.insert_primitive(Quad {
2250 order: 0,
2251 pad: 0,
2252 bounds: quad.bounds.scale(scale_factor),
2253 content_mask: content_mask.scale(scale_factor),
2254 background: quad.background,
2255 border_color: quad.border_color,
2256 corner_radii: quad.corner_radii.scale(scale_factor),
2257 border_widths: quad.border_widths.scale(scale_factor),
2258 });
2259 }
2260
2261 /// Paint the given `Path` into the scene for the next frame at the current z-index.
2262 ///
2263 /// This method should only be called as part of the paint phase of element drawing.
2264 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
2265 debug_assert_eq!(
2266 self.window.draw_phase,
2267 DrawPhase::Paint,
2268 "this method can only be called during paint"
2269 );
2270
2271 let scale_factor = self.scale_factor();
2272 let content_mask = self.content_mask();
2273 path.content_mask = content_mask;
2274 path.color = color.into();
2275 self.window
2276 .next_frame
2277 .scene
2278 .insert_primitive(path.scale(scale_factor));
2279 }
2280
2281 /// Paint an underline into the scene for the next frame at the current z-index.
2282 ///
2283 /// This method should only be called as part of the paint phase of element drawing.
2284 pub fn paint_underline(
2285 &mut self,
2286 origin: Point<Pixels>,
2287 width: Pixels,
2288 style: &UnderlineStyle,
2289 ) {
2290 debug_assert_eq!(
2291 self.window.draw_phase,
2292 DrawPhase::Paint,
2293 "this method can only be called during paint"
2294 );
2295
2296 let scale_factor = self.scale_factor();
2297 let height = if style.wavy {
2298 style.thickness * 3.
2299 } else {
2300 style.thickness
2301 };
2302 let bounds = Bounds {
2303 origin,
2304 size: size(width, height),
2305 };
2306 let content_mask = self.content_mask();
2307
2308 self.window.next_frame.scene.insert_primitive(Underline {
2309 order: 0,
2310 pad: 0,
2311 bounds: bounds.scale(scale_factor),
2312 content_mask: content_mask.scale(scale_factor),
2313 color: style.color.unwrap_or_default(),
2314 thickness: style.thickness.scale(scale_factor),
2315 wavy: style.wavy,
2316 });
2317 }
2318
2319 /// Paint a strikethrough into the scene for the next frame at the current z-index.
2320 ///
2321 /// This method should only be called as part of the paint phase of element drawing.
2322 pub fn paint_strikethrough(
2323 &mut self,
2324 origin: Point<Pixels>,
2325 width: Pixels,
2326 style: &StrikethroughStyle,
2327 ) {
2328 debug_assert_eq!(
2329 self.window.draw_phase,
2330 DrawPhase::Paint,
2331 "this method can only be called during paint"
2332 );
2333
2334 let scale_factor = self.scale_factor();
2335 let height = style.thickness;
2336 let bounds = Bounds {
2337 origin,
2338 size: size(width, height),
2339 };
2340 let content_mask = self.content_mask();
2341
2342 self.window.next_frame.scene.insert_primitive(Underline {
2343 order: 0,
2344 pad: 0,
2345 bounds: bounds.scale(scale_factor),
2346 content_mask: content_mask.scale(scale_factor),
2347 thickness: style.thickness.scale(scale_factor),
2348 color: style.color.unwrap_or_default(),
2349 wavy: false,
2350 });
2351 }
2352
2353 /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
2354 ///
2355 /// The y component of the origin is the baseline of the glyph.
2356 /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2357 /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2358 /// This method is only useful if you need to paint a single glyph that has already been shaped.
2359 ///
2360 /// This method should only be called as part of the paint phase of element drawing.
2361 pub fn paint_glyph(
2362 &mut self,
2363 origin: Point<Pixels>,
2364 font_id: FontId,
2365 glyph_id: GlyphId,
2366 font_size: Pixels,
2367 color: Hsla,
2368 ) -> Result<()> {
2369 debug_assert_eq!(
2370 self.window.draw_phase,
2371 DrawPhase::Paint,
2372 "this method can only be called during paint"
2373 );
2374
2375 let scale_factor = self.scale_factor();
2376 let glyph_origin = origin.scale(scale_factor);
2377 let subpixel_variant = Point {
2378 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2379 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2380 };
2381 let params = RenderGlyphParams {
2382 font_id,
2383 glyph_id,
2384 font_size,
2385 subpixel_variant,
2386 scale_factor,
2387 is_emoji: false,
2388 };
2389
2390 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
2391 if !raster_bounds.is_zero() {
2392 let tile = self
2393 .window
2394 .sprite_atlas
2395 .get_or_insert_with(¶ms.clone().into(), &mut || {
2396 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
2397 Ok(Some((size, Cow::Owned(bytes))))
2398 })?
2399 .expect("Callback above only errors or returns Some");
2400 let bounds = Bounds {
2401 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2402 size: tile.bounds.size.map(Into::into),
2403 };
2404 let content_mask = self.content_mask().scale(scale_factor);
2405 self.window
2406 .next_frame
2407 .scene
2408 .insert_primitive(MonochromeSprite {
2409 order: 0,
2410 pad: 0,
2411 bounds,
2412 content_mask,
2413 color,
2414 tile,
2415 transformation: TransformationMatrix::unit(),
2416 });
2417 }
2418 Ok(())
2419 }
2420
2421 /// Paints an emoji glyph into the scene for the next frame at the current z-index.
2422 ///
2423 /// The y component of the origin is the baseline of the glyph.
2424 /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2425 /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2426 /// This method is only useful if you need to paint a single emoji that has already been shaped.
2427 ///
2428 /// This method should only be called as part of the paint phase of element drawing.
2429 pub fn paint_emoji(
2430 &mut self,
2431 origin: Point<Pixels>,
2432 font_id: FontId,
2433 glyph_id: GlyphId,
2434 font_size: Pixels,
2435 ) -> Result<()> {
2436 debug_assert_eq!(
2437 self.window.draw_phase,
2438 DrawPhase::Paint,
2439 "this method can only be called during paint"
2440 );
2441
2442 let scale_factor = self.scale_factor();
2443 let glyph_origin = origin.scale(scale_factor);
2444 let params = RenderGlyphParams {
2445 font_id,
2446 glyph_id,
2447 font_size,
2448 // We don't render emojis with subpixel variants.
2449 subpixel_variant: Default::default(),
2450 scale_factor,
2451 is_emoji: true,
2452 };
2453
2454 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
2455 if !raster_bounds.is_zero() {
2456 let tile = self
2457 .window
2458 .sprite_atlas
2459 .get_or_insert_with(¶ms.clone().into(), &mut || {
2460 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
2461 Ok(Some((size, Cow::Owned(bytes))))
2462 })?
2463 .expect("Callback above only errors or returns Some");
2464
2465 let bounds = Bounds {
2466 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2467 size: tile.bounds.size.map(Into::into),
2468 };
2469 let content_mask = self.content_mask().scale(scale_factor);
2470
2471 self.window
2472 .next_frame
2473 .scene
2474 .insert_primitive(PolychromeSprite {
2475 order: 0,
2476 grayscale: false,
2477 bounds,
2478 corner_radii: Default::default(),
2479 content_mask,
2480 tile,
2481 });
2482 }
2483 Ok(())
2484 }
2485
2486 /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
2487 ///
2488 /// This method should only be called as part of the paint phase of element drawing.
2489 pub fn paint_svg(
2490 &mut self,
2491 bounds: Bounds<Pixels>,
2492 path: SharedString,
2493 transformation: TransformationMatrix,
2494 color: Hsla,
2495 ) -> Result<()> {
2496 debug_assert_eq!(
2497 self.window.draw_phase,
2498 DrawPhase::Paint,
2499 "this method can only be called during paint"
2500 );
2501
2502 let scale_factor = self.scale_factor();
2503 let bounds = bounds.scale(scale_factor);
2504 // Render the SVG at twice the size to get a higher quality result.
2505 let params = RenderSvgParams {
2506 path,
2507 size: bounds
2508 .size
2509 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
2510 };
2511
2512 let Some(tile) =
2513 self.window
2514 .sprite_atlas
2515 .get_or_insert_with(¶ms.clone().into(), &mut || {
2516 let Some(bytes) = self.svg_renderer.render(¶ms)? else {
2517 return Ok(None);
2518 };
2519 Ok(Some((params.size, Cow::Owned(bytes))))
2520 })?
2521 else {
2522 return Ok(());
2523 };
2524 let content_mask = self.content_mask().scale(scale_factor);
2525
2526 self.window
2527 .next_frame
2528 .scene
2529 .insert_primitive(MonochromeSprite {
2530 order: 0,
2531 pad: 0,
2532 bounds,
2533 content_mask,
2534 color,
2535 tile,
2536 transformation,
2537 });
2538
2539 Ok(())
2540 }
2541
2542 /// Paint an image into the scene for the next frame at the current z-index.
2543 ///
2544 /// This method should only be called as part of the paint phase of element drawing.
2545 pub fn paint_image(
2546 &mut self,
2547 bounds: Bounds<Pixels>,
2548 corner_radii: Corners<Pixels>,
2549 data: Arc<ImageData>,
2550 grayscale: bool,
2551 ) -> Result<()> {
2552 debug_assert_eq!(
2553 self.window.draw_phase,
2554 DrawPhase::Paint,
2555 "this method can only be called during paint"
2556 );
2557
2558 let scale_factor = self.scale_factor();
2559 let bounds = bounds.scale(scale_factor);
2560 let params = RenderImageParams { image_id: data.id };
2561
2562 let tile = self
2563 .window
2564 .sprite_atlas
2565 .get_or_insert_with(¶ms.clone().into(), &mut || {
2566 Ok(Some((data.size(), Cow::Borrowed(data.as_bytes()))))
2567 })?
2568 .expect("Callback above only returns Some");
2569 let content_mask = self.content_mask().scale(scale_factor);
2570 let corner_radii = corner_radii.scale(scale_factor);
2571
2572 self.window
2573 .next_frame
2574 .scene
2575 .insert_primitive(PolychromeSprite {
2576 order: 0,
2577 grayscale,
2578 bounds,
2579 content_mask,
2580 corner_radii,
2581 tile,
2582 });
2583 Ok(())
2584 }
2585
2586 /// Paint a surface into the scene for the next frame at the current z-index.
2587 ///
2588 /// This method should only be called as part of the paint phase of element drawing.
2589 #[cfg(target_os = "macos")]
2590 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
2591 debug_assert_eq!(
2592 self.window.draw_phase,
2593 DrawPhase::Paint,
2594 "this method can only be called during paint"
2595 );
2596
2597 let scale_factor = self.scale_factor();
2598 let bounds = bounds.scale(scale_factor);
2599 let content_mask = self.content_mask().scale(scale_factor);
2600 self.window
2601 .next_frame
2602 .scene
2603 .insert_primitive(crate::Surface {
2604 order: 0,
2605 bounds,
2606 content_mask,
2607 image_buffer,
2608 });
2609 }
2610
2611 #[must_use]
2612 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
2613 /// layout is being requested, along with the layout ids of any children. This method is called during
2614 /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
2615 ///
2616 /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2617 pub fn request_layout(
2618 &mut self,
2619 style: Style,
2620 children: impl IntoIterator<Item = LayoutId>,
2621 ) -> LayoutId {
2622 debug_assert_eq!(
2623 self.window.draw_phase,
2624 DrawPhase::Prepaint,
2625 "this method can only be called during request_layout, or prepaint"
2626 );
2627
2628 self.app.layout_id_buffer.clear();
2629 self.app.layout_id_buffer.extend(children);
2630 let rem_size = self.rem_size();
2631
2632 self.window.layout_engine.as_mut().unwrap().request_layout(
2633 style,
2634 rem_size,
2635 &self.app.layout_id_buffer,
2636 )
2637 }
2638
2639 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
2640 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
2641 /// determine the element's size. One place this is used internally is when measuring text.
2642 ///
2643 /// The given closure is invoked at layout time with the known dimensions and available space and
2644 /// returns a `Size`.
2645 ///
2646 /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2647 pub fn request_measured_layout<
2648 F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut WindowContext) -> Size<Pixels>
2649 + 'static,
2650 >(
2651 &mut self,
2652 style: Style,
2653 measure: F,
2654 ) -> LayoutId {
2655 debug_assert_eq!(
2656 self.window.draw_phase,
2657 DrawPhase::Prepaint,
2658 "this method can only be called during request_layout, or prepaint"
2659 );
2660
2661 let rem_size = self.rem_size();
2662 self.window
2663 .layout_engine
2664 .as_mut()
2665 .unwrap()
2666 .request_measured_layout(style, rem_size, measure)
2667 }
2668
2669 /// Compute the layout for the given id within the given available space.
2670 /// This method is called for its side effect, typically by the framework prior to painting.
2671 /// After calling it, you can request the bounds of the given layout node id or any descendant.
2672 ///
2673 /// This method should only be called as part of the prepaint phase of element drawing.
2674 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
2675 debug_assert_eq!(
2676 self.window.draw_phase,
2677 DrawPhase::Prepaint,
2678 "this method can only be called during request_layout, or prepaint"
2679 );
2680
2681 let mut layout_engine = self.window.layout_engine.take().unwrap();
2682 layout_engine.compute_layout(layout_id, available_space, self);
2683 self.window.layout_engine = Some(layout_engine);
2684 }
2685
2686 /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
2687 /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
2688 ///
2689 /// This method should only be called as part of element drawing.
2690 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
2691 debug_assert_eq!(
2692 self.window.draw_phase,
2693 DrawPhase::Prepaint,
2694 "this method can only be called during request_layout, prepaint, or paint"
2695 );
2696
2697 let mut bounds = self
2698 .window
2699 .layout_engine
2700 .as_mut()
2701 .unwrap()
2702 .layout_bounds(layout_id)
2703 .map(Into::into);
2704 bounds.origin += self.element_offset();
2705 bounds
2706 }
2707
2708 /// This method should be called during `prepaint`. You can use
2709 /// the returned [Hitbox] during `paint` or in an event handler
2710 /// to determine whether the inserted hitbox was the topmost.
2711 ///
2712 /// This method should only be called as part of the prepaint phase of element drawing.
2713 pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, opaque: bool) -> Hitbox {
2714 debug_assert_eq!(
2715 self.window.draw_phase,
2716 DrawPhase::Prepaint,
2717 "this method can only be called during prepaint"
2718 );
2719
2720 let content_mask = self.content_mask();
2721 let window = &mut self.window;
2722 let id = window.next_hitbox_id;
2723 window.next_hitbox_id.0 += 1;
2724 let hitbox = Hitbox {
2725 id,
2726 bounds,
2727 content_mask,
2728 opaque,
2729 };
2730 window.next_frame.hitboxes.push(hitbox.clone());
2731 hitbox
2732 }
2733
2734 /// Sets the key context for the current element. This context will be used to translate
2735 /// keybindings into actions.
2736 ///
2737 /// This method should only be called as part of the paint phase of element drawing.
2738 pub fn set_key_context(&mut self, context: KeyContext) {
2739 debug_assert_eq!(
2740 self.window.draw_phase,
2741 DrawPhase::Paint,
2742 "this method can only be called during paint"
2743 );
2744 self.window
2745 .next_frame
2746 .dispatch_tree
2747 .set_key_context(context);
2748 }
2749
2750 /// Sets the focus handle for the current element. This handle will be used to manage focus state
2751 /// and keyboard event dispatch for the element.
2752 ///
2753 /// This method should only be called as part of the paint phase of element drawing.
2754 pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle) {
2755 debug_assert_eq!(
2756 self.window.draw_phase,
2757 DrawPhase::Paint,
2758 "this method can only be called during paint"
2759 );
2760 self.window
2761 .next_frame
2762 .dispatch_tree
2763 .set_focus_id(focus_handle.id);
2764 }
2765
2766 /// Sets the view id for the current element, which will be used to manage view caching.
2767 ///
2768 /// This method should only be called as part of element prepaint. We plan on removing this
2769 /// method eventually when we solve some issues that require us to construct editor elements
2770 /// directly instead of always using editors via views.
2771 pub fn set_view_id(&mut self, view_id: EntityId) {
2772 debug_assert_eq!(
2773 self.window.draw_phase,
2774 DrawPhase::Prepaint,
2775 "this method can only be called during prepaint"
2776 );
2777 self.window.next_frame.dispatch_tree.set_view_id(view_id);
2778 }
2779
2780 /// Get the last view id for the current element
2781 pub fn parent_view_id(&mut self) -> Option<EntityId> {
2782 self.window.next_frame.dispatch_tree.parent_view_id()
2783 }
2784
2785 /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
2786 /// platform to receive textual input with proper integration with concerns such
2787 /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
2788 /// rendered.
2789 ///
2790 /// This method should only be called as part of the paint phase of element drawing.
2791 ///
2792 /// [element_input_handler]: crate::ElementInputHandler
2793 pub fn handle_input(&mut self, focus_handle: &FocusHandle, input_handler: impl InputHandler) {
2794 debug_assert_eq!(
2795 self.window.draw_phase,
2796 DrawPhase::Paint,
2797 "this method can only be called during paint"
2798 );
2799
2800 if focus_handle.is_focused(self) {
2801 let cx = self.to_async();
2802 self.window
2803 .next_frame
2804 .input_handlers
2805 .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
2806 }
2807 }
2808
2809 /// Register a mouse event listener on the window for the next frame. The type of event
2810 /// is determined by the first parameter of the given listener. When the next frame is rendered
2811 /// the listener will be cleared.
2812 ///
2813 /// This method should only be called as part of the paint phase of element drawing.
2814 pub fn on_mouse_event<Event: MouseEvent>(
2815 &mut self,
2816 mut handler: impl FnMut(&Event, DispatchPhase, &mut WindowContext) + 'static,
2817 ) {
2818 debug_assert_eq!(
2819 self.window.draw_phase,
2820 DrawPhase::Paint,
2821 "this method can only be called during paint"
2822 );
2823
2824 self.window.next_frame.mouse_listeners.push(Some(Box::new(
2825 move |event: &dyn Any, phase: DispatchPhase, cx: &mut WindowContext<'_>| {
2826 if let Some(event) = event.downcast_ref() {
2827 handler(event, phase, cx)
2828 }
2829 },
2830 )));
2831 }
2832
2833 /// Register a key event listener on the window for the next frame. The type of event
2834 /// is determined by the first parameter of the given listener. When the next frame is rendered
2835 /// the listener will be cleared.
2836 ///
2837 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2838 /// a specific need to register a global listener.
2839 ///
2840 /// This method should only be called as part of the paint phase of element drawing.
2841 pub fn on_key_event<Event: KeyEvent>(
2842 &mut self,
2843 listener: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
2844 ) {
2845 debug_assert_eq!(
2846 self.window.draw_phase,
2847 DrawPhase::Paint,
2848 "this method can only be called during paint"
2849 );
2850
2851 self.window.next_frame.dispatch_tree.on_key_event(Rc::new(
2852 move |event: &dyn Any, phase, cx: &mut WindowContext<'_>| {
2853 if let Some(event) = event.downcast_ref::<Event>() {
2854 listener(event, phase, cx)
2855 }
2856 },
2857 ));
2858 }
2859
2860 /// Register a modifiers changed event listener on the window for the next frame.
2861 ///
2862 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2863 /// a specific need to register a global listener.
2864 ///
2865 /// This method should only be called as part of the paint phase of element drawing.
2866 pub fn on_modifiers_changed(
2867 &mut self,
2868 listener: impl Fn(&ModifiersChangedEvent, &mut WindowContext) + 'static,
2869 ) {
2870 debug_assert_eq!(
2871 self.window.draw_phase,
2872 DrawPhase::Paint,
2873 "this method can only be called during paint"
2874 );
2875
2876 self.window
2877 .next_frame
2878 .dispatch_tree
2879 .on_modifiers_changed(Rc::new(
2880 move |event: &ModifiersChangedEvent, cx: &mut WindowContext<'_>| {
2881 listener(event, cx)
2882 },
2883 ));
2884 }
2885
2886 fn reset_cursor_style(&self) {
2887 // Set the cursor only if we're the active window.
2888 if self.is_window_active() {
2889 let style = self
2890 .window
2891 .rendered_frame
2892 .cursor_styles
2893 .iter()
2894 .rev()
2895 .find(|request| request.hitbox_id.is_hovered(self))
2896 .map(|request| request.style)
2897 .unwrap_or(CursorStyle::Arrow);
2898 self.platform.set_cursor_style(style);
2899 }
2900 }
2901
2902 /// Dispatch a given keystroke as though the user had typed it.
2903 /// You can create a keystroke with Keystroke::parse("").
2904 pub fn dispatch_keystroke(&mut self, keystroke: Keystroke) -> bool {
2905 let keystroke = keystroke.with_simulated_ime();
2906 let result = self.dispatch_event(PlatformInput::KeyDown(KeyDownEvent {
2907 keystroke: keystroke.clone(),
2908 is_held: false,
2909 }));
2910 if !result.propagate {
2911 return true;
2912 }
2913
2914 if let Some(input) = keystroke.ime_key {
2915 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
2916 input_handler.dispatch_input(&input, self);
2917 self.window.platform_window.set_input_handler(input_handler);
2918 return true;
2919 }
2920 }
2921
2922 false
2923 }
2924
2925 /// Represent this action as a key binding string, to display in the UI.
2926 pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
2927 self.bindings_for_action(action)
2928 .into_iter()
2929 .next()
2930 .map(|binding| {
2931 binding
2932 .keystrokes()
2933 .iter()
2934 .map(ToString::to_string)
2935 .collect::<Vec<_>>()
2936 .join(" ")
2937 })
2938 .unwrap_or_else(|| action.name().to_string())
2939 }
2940
2941 /// Dispatch a mouse or keyboard event on the window.
2942 #[profiling::function]
2943 pub fn dispatch_event(&mut self, event: PlatformInput) -> DispatchEventResult {
2944 self.window.last_input_timestamp.set(Instant::now());
2945 // Handlers may set this to false by calling `stop_propagation`.
2946 self.app.propagate_event = true;
2947 // Handlers may set this to true by calling `prevent_default`.
2948 self.window.default_prevented = false;
2949
2950 let event = match event {
2951 // Track the mouse position with our own state, since accessing the platform
2952 // API for the mouse position can only occur on the main thread.
2953 PlatformInput::MouseMove(mouse_move) => {
2954 self.window.mouse_position = mouse_move.position;
2955 self.window.modifiers = mouse_move.modifiers;
2956 PlatformInput::MouseMove(mouse_move)
2957 }
2958 PlatformInput::MouseDown(mouse_down) => {
2959 self.window.mouse_position = mouse_down.position;
2960 self.window.modifiers = mouse_down.modifiers;
2961 PlatformInput::MouseDown(mouse_down)
2962 }
2963 PlatformInput::MouseUp(mouse_up) => {
2964 self.window.mouse_position = mouse_up.position;
2965 self.window.modifiers = mouse_up.modifiers;
2966 PlatformInput::MouseUp(mouse_up)
2967 }
2968 PlatformInput::MouseExited(mouse_exited) => {
2969 self.window.modifiers = mouse_exited.modifiers;
2970 PlatformInput::MouseExited(mouse_exited)
2971 }
2972 PlatformInput::ModifiersChanged(modifiers_changed) => {
2973 self.window.modifiers = modifiers_changed.modifiers;
2974 PlatformInput::ModifiersChanged(modifiers_changed)
2975 }
2976 PlatformInput::ScrollWheel(scroll_wheel) => {
2977 self.window.mouse_position = scroll_wheel.position;
2978 self.window.modifiers = scroll_wheel.modifiers;
2979 PlatformInput::ScrollWheel(scroll_wheel)
2980 }
2981 // Translate dragging and dropping of external files from the operating system
2982 // to internal drag and drop events.
2983 PlatformInput::FileDrop(file_drop) => match file_drop {
2984 FileDropEvent::Entered { position, paths } => {
2985 self.window.mouse_position = position;
2986 if self.active_drag.is_none() {
2987 self.active_drag = Some(AnyDrag {
2988 value: Box::new(paths.clone()),
2989 view: self.new_view(|_| paths).into(),
2990 cursor_offset: position,
2991 });
2992 }
2993 PlatformInput::MouseMove(MouseMoveEvent {
2994 position,
2995 pressed_button: Some(MouseButton::Left),
2996 modifiers: Modifiers::default(),
2997 })
2998 }
2999 FileDropEvent::Pending { position } => {
3000 self.window.mouse_position = position;
3001 PlatformInput::MouseMove(MouseMoveEvent {
3002 position,
3003 pressed_button: Some(MouseButton::Left),
3004 modifiers: Modifiers::default(),
3005 })
3006 }
3007 FileDropEvent::Submit { position } => {
3008 self.activate(true);
3009 self.window.mouse_position = position;
3010 PlatformInput::MouseUp(MouseUpEvent {
3011 button: MouseButton::Left,
3012 position,
3013 modifiers: Modifiers::default(),
3014 click_count: 1,
3015 })
3016 }
3017 FileDropEvent::Exited => {
3018 self.active_drag.take();
3019 PlatformInput::FileDrop(FileDropEvent::Exited)
3020 }
3021 },
3022 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3023 };
3024
3025 if let Some(any_mouse_event) = event.mouse_event() {
3026 self.dispatch_mouse_event(any_mouse_event);
3027 } else if let Some(any_key_event) = event.keyboard_event() {
3028 self.dispatch_key_event(any_key_event);
3029 }
3030
3031 DispatchEventResult {
3032 propagate: self.app.propagate_event,
3033 default_prevented: self.window.default_prevented,
3034 }
3035 }
3036
3037 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
3038 let hit_test = self.window.rendered_frame.hit_test(self.mouse_position());
3039 if hit_test != self.window.mouse_hit_test {
3040 self.window.mouse_hit_test = hit_test;
3041 self.reset_cursor_style();
3042 }
3043
3044 let mut mouse_listeners = mem::take(&mut self.window.rendered_frame.mouse_listeners);
3045
3046 // Capture phase, events bubble from back to front. Handlers for this phase are used for
3047 // special purposes, such as detecting events outside of a given Bounds.
3048 for listener in &mut mouse_listeners {
3049 let listener = listener.as_mut().unwrap();
3050 listener(event, DispatchPhase::Capture, self);
3051 if !self.app.propagate_event {
3052 break;
3053 }
3054 }
3055
3056 // Bubble phase, where most normal handlers do their work.
3057 if self.app.propagate_event {
3058 for listener in mouse_listeners.iter_mut().rev() {
3059 let listener = listener.as_mut().unwrap();
3060 listener(event, DispatchPhase::Bubble, self);
3061 if !self.app.propagate_event {
3062 break;
3063 }
3064 }
3065 }
3066
3067 self.window.rendered_frame.mouse_listeners = mouse_listeners;
3068
3069 if self.has_active_drag() {
3070 if event.is::<MouseMoveEvent>() {
3071 // If this was a mouse move event, redraw the window so that the
3072 // active drag can follow the mouse cursor.
3073 self.refresh();
3074 } else if event.is::<MouseUpEvent>() {
3075 // If this was a mouse up event, cancel the active drag and redraw
3076 // the window.
3077 self.active_drag = None;
3078 self.refresh();
3079 }
3080 }
3081 }
3082
3083 fn dispatch_key_event(&mut self, event: &dyn Any) {
3084 if self.window.dirty.get() {
3085 self.draw();
3086 }
3087
3088 let node_id = self
3089 .window
3090 .focus
3091 .and_then(|focus_id| {
3092 self.window
3093 .rendered_frame
3094 .dispatch_tree
3095 .focusable_node_id(focus_id)
3096 })
3097 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3098
3099 let dispatch_path = self
3100 .window
3101 .rendered_frame
3102 .dispatch_tree
3103 .dispatch_path(node_id);
3104
3105 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3106 let KeymatchResult { bindings, pending } = self
3107 .window
3108 .rendered_frame
3109 .dispatch_tree
3110 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
3111
3112 if pending {
3113 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
3114 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
3115 {
3116 currently_pending = PendingInput::default();
3117 }
3118 currently_pending.focus = self.window.focus;
3119 currently_pending
3120 .keystrokes
3121 .push(key_down_event.keystroke.clone());
3122 for binding in bindings {
3123 currently_pending.bindings.push(binding);
3124 }
3125
3126 currently_pending.timer = Some(self.spawn(|mut cx| async move {
3127 cx.background_executor.timer(Duration::from_secs(1)).await;
3128 cx.update(move |cx| {
3129 cx.clear_pending_keystrokes();
3130 let Some(currently_pending) = cx.window.pending_input.take() else {
3131 return;
3132 };
3133 cx.pending_input_changed();
3134 cx.replay_pending_input(currently_pending);
3135 })
3136 .log_err();
3137 }));
3138
3139 self.window.pending_input = Some(currently_pending);
3140 self.pending_input_changed();
3141
3142 self.propagate_event = false;
3143
3144 return;
3145 } else if let Some(currently_pending) = self.window.pending_input.take() {
3146 self.pending_input_changed();
3147 if bindings
3148 .iter()
3149 .all(|binding| !currently_pending.used_by_binding(binding))
3150 {
3151 self.replay_pending_input(currently_pending)
3152 }
3153 }
3154
3155 if !bindings.is_empty() {
3156 self.clear_pending_keystrokes();
3157 }
3158
3159 self.propagate_event = true;
3160 for binding in bindings {
3161 self.dispatch_action_on_node(node_id, binding.action.as_ref());
3162 if !self.propagate_event {
3163 self.dispatch_keystroke_observers(event, Some(binding.action));
3164 return;
3165 }
3166 }
3167 }
3168
3169 self.dispatch_key_down_up_event(event, &dispatch_path);
3170 if !self.propagate_event {
3171 return;
3172 }
3173
3174 self.dispatch_modifiers_changed_event(event, &dispatch_path);
3175 if !self.propagate_event {
3176 return;
3177 }
3178
3179 self.dispatch_keystroke_observers(event, None);
3180 }
3181
3182 fn pending_input_changed(&mut self) {
3183 self.window
3184 .pending_input_observers
3185 .clone()
3186 .retain(&(), |callback| callback(self));
3187 }
3188
3189 fn dispatch_key_down_up_event(
3190 &mut self,
3191 event: &dyn Any,
3192 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3193 ) {
3194 // Capture phase
3195 for node_id in dispatch_path {
3196 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3197
3198 for key_listener in node.key_listeners.clone() {
3199 key_listener(event, DispatchPhase::Capture, self);
3200 if !self.propagate_event {
3201 return;
3202 }
3203 }
3204 }
3205
3206 // Bubble phase
3207 for node_id in dispatch_path.iter().rev() {
3208 // Handle low level key events
3209 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3210 for key_listener in node.key_listeners.clone() {
3211 key_listener(event, DispatchPhase::Bubble, self);
3212 if !self.propagate_event {
3213 return;
3214 }
3215 }
3216 }
3217 }
3218
3219 fn dispatch_modifiers_changed_event(
3220 &mut self,
3221 event: &dyn Any,
3222 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3223 ) {
3224 let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
3225 return;
3226 };
3227 for node_id in dispatch_path.iter().rev() {
3228 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3229 for listener in node.modifiers_changed_listeners.clone() {
3230 listener(event, self);
3231 if !self.propagate_event {
3232 return;
3233 }
3234 }
3235 }
3236 }
3237
3238 /// Determine whether a potential multi-stroke key binding is in progress on this window.
3239 pub fn has_pending_keystrokes(&self) -> bool {
3240 self.window
3241 .rendered_frame
3242 .dispatch_tree
3243 .has_pending_keystrokes()
3244 }
3245
3246 /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
3247 pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
3248 self.window
3249 .pending_input
3250 .as_ref()
3251 .map(|pending_input| pending_input.keystrokes.as_slice())
3252 }
3253
3254 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
3255 let node_id = self
3256 .window
3257 .focus
3258 .and_then(|focus_id| {
3259 self.window
3260 .rendered_frame
3261 .dispatch_tree
3262 .focusable_node_id(focus_id)
3263 })
3264 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3265
3266 if self.window.focus != currently_pending.focus {
3267 return;
3268 }
3269
3270 let input = currently_pending.input();
3271
3272 self.propagate_event = true;
3273 for binding in currently_pending.bindings {
3274 self.dispatch_action_on_node(node_id, binding.action.as_ref());
3275 if !self.propagate_event {
3276 return;
3277 }
3278 }
3279
3280 let dispatch_path = self
3281 .window
3282 .rendered_frame
3283 .dispatch_tree
3284 .dispatch_path(node_id);
3285
3286 for keystroke in currently_pending.keystrokes {
3287 let event = KeyDownEvent {
3288 keystroke,
3289 is_held: false,
3290 };
3291
3292 self.dispatch_key_down_up_event(&event, &dispatch_path);
3293 if !self.propagate_event {
3294 return;
3295 }
3296 }
3297
3298 if !input.is_empty() {
3299 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
3300 input_handler.dispatch_input(&input, self);
3301 self.window.platform_window.set_input_handler(input_handler)
3302 }
3303 }
3304 }
3305
3306 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: &dyn Action) {
3307 let dispatch_path = self
3308 .window
3309 .rendered_frame
3310 .dispatch_tree
3311 .dispatch_path(node_id);
3312
3313 // Capture phase for global actions.
3314 self.propagate_event = true;
3315 if let Some(mut global_listeners) = self
3316 .global_action_listeners
3317 .remove(&action.as_any().type_id())
3318 {
3319 for listener in &global_listeners {
3320 listener(action.as_any(), DispatchPhase::Capture, self);
3321 if !self.propagate_event {
3322 break;
3323 }
3324 }
3325
3326 global_listeners.extend(
3327 self.global_action_listeners
3328 .remove(&action.as_any().type_id())
3329 .unwrap_or_default(),
3330 );
3331
3332 self.global_action_listeners
3333 .insert(action.as_any().type_id(), global_listeners);
3334 }
3335
3336 if !self.propagate_event {
3337 return;
3338 }
3339
3340 // Capture phase for window actions.
3341 for node_id in &dispatch_path {
3342 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3343 for DispatchActionListener {
3344 action_type,
3345 listener,
3346 } in node.action_listeners.clone()
3347 {
3348 let any_action = action.as_any();
3349 if action_type == any_action.type_id() {
3350 listener(any_action, DispatchPhase::Capture, self);
3351
3352 if !self.propagate_event {
3353 return;
3354 }
3355 }
3356 }
3357 }
3358
3359 // Bubble phase for window actions.
3360 for node_id in dispatch_path.iter().rev() {
3361 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3362 for DispatchActionListener {
3363 action_type,
3364 listener,
3365 } in node.action_listeners.clone()
3366 {
3367 let any_action = action.as_any();
3368 if action_type == any_action.type_id() {
3369 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
3370 listener(any_action, DispatchPhase::Bubble, self);
3371
3372 if !self.propagate_event {
3373 return;
3374 }
3375 }
3376 }
3377 }
3378
3379 // Bubble phase for global actions.
3380 if let Some(mut global_listeners) = self
3381 .global_action_listeners
3382 .remove(&action.as_any().type_id())
3383 {
3384 for listener in global_listeners.iter().rev() {
3385 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
3386
3387 listener(action.as_any(), DispatchPhase::Bubble, self);
3388 if !self.propagate_event {
3389 break;
3390 }
3391 }
3392
3393 global_listeners.extend(
3394 self.global_action_listeners
3395 .remove(&action.as_any().type_id())
3396 .unwrap_or_default(),
3397 );
3398
3399 self.global_action_listeners
3400 .insert(action.as_any().type_id(), global_listeners);
3401 }
3402 }
3403
3404 /// Register the given handler to be invoked whenever the global of the given type
3405 /// is updated.
3406 pub fn observe_global<G: Global>(
3407 &mut self,
3408 f: impl Fn(&mut WindowContext<'_>) + 'static,
3409 ) -> Subscription {
3410 let window_handle = self.window.handle;
3411 let (subscription, activate) = self.global_observers.insert(
3412 TypeId::of::<G>(),
3413 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
3414 );
3415 self.app.defer(move |_| activate());
3416 subscription
3417 }
3418
3419 /// Focus the current window and bring it to the foreground at the platform level.
3420 pub fn activate_window(&self) {
3421 self.window.platform_window.activate();
3422 }
3423
3424 /// Minimize the current window at the platform level.
3425 pub fn minimize_window(&self) {
3426 self.window.platform_window.minimize();
3427 }
3428
3429 /// Toggle full screen status on the current window at the platform level.
3430 pub fn toggle_fullscreen(&self) {
3431 self.window.platform_window.toggle_fullscreen();
3432 }
3433
3434 /// Present a platform dialog.
3435 /// The provided message will be presented, along with buttons for each answer.
3436 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
3437 pub fn prompt(
3438 &mut self,
3439 level: PromptLevel,
3440 message: &str,
3441 detail: Option<&str>,
3442 answers: &[&str],
3443 ) -> oneshot::Receiver<usize> {
3444 let prompt_builder = self.app.prompt_builder.take();
3445 let Some(prompt_builder) = prompt_builder else {
3446 unreachable!("Re-entrant window prompting is not supported by GPUI");
3447 };
3448
3449 let receiver = match &prompt_builder {
3450 PromptBuilder::Default => self
3451 .window
3452 .platform_window
3453 .prompt(level, message, detail, answers)
3454 .unwrap_or_else(|| {
3455 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
3456 }),
3457 PromptBuilder::Custom(_) => {
3458 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
3459 }
3460 };
3461
3462 self.app.prompt_builder = Some(prompt_builder);
3463
3464 receiver
3465 }
3466
3467 fn build_custom_prompt(
3468 &mut self,
3469 prompt_builder: &PromptBuilder,
3470 level: PromptLevel,
3471 message: &str,
3472 detail: Option<&str>,
3473 answers: &[&str],
3474 ) -> oneshot::Receiver<usize> {
3475 let (sender, receiver) = oneshot::channel();
3476 let handle = PromptHandle::new(sender);
3477 let handle = (prompt_builder)(level, message, detail, answers, handle, self);
3478 self.window.prompt = Some(handle);
3479 receiver
3480 }
3481
3482 /// Returns all available actions for the focused element.
3483 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
3484 let node_id = self
3485 .window
3486 .focus
3487 .and_then(|focus_id| {
3488 self.window
3489 .rendered_frame
3490 .dispatch_tree
3491 .focusable_node_id(focus_id)
3492 })
3493 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3494
3495 let mut actions = self
3496 .window
3497 .rendered_frame
3498 .dispatch_tree
3499 .available_actions(node_id);
3500 for action_type in self.global_action_listeners.keys() {
3501 if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
3502 let action = self.actions.build_action_type(action_type).ok();
3503 if let Some(action) = action {
3504 actions.insert(ix, action);
3505 }
3506 }
3507 }
3508 actions
3509 }
3510
3511 /// Returns key bindings that invoke the given action on the currently focused element.
3512 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
3513 self.window
3514 .rendered_frame
3515 .dispatch_tree
3516 .bindings_for_action(
3517 action,
3518 &self.window.rendered_frame.dispatch_tree.context_stack,
3519 )
3520 }
3521
3522 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
3523 pub fn bindings_for_action_in(
3524 &self,
3525 action: &dyn Action,
3526 focus_handle: &FocusHandle,
3527 ) -> Vec<KeyBinding> {
3528 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
3529
3530 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
3531 return vec![];
3532 };
3533 let context_stack: Vec<_> = dispatch_tree
3534 .dispatch_path(node_id)
3535 .into_iter()
3536 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
3537 .collect();
3538 dispatch_tree.bindings_for_action(action, &context_stack)
3539 }
3540
3541 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
3542 pub fn listener_for<V: Render, E>(
3543 &self,
3544 view: &View<V>,
3545 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
3546 ) -> impl Fn(&E, &mut WindowContext) + 'static {
3547 let view = view.downgrade();
3548 move |e: &E, cx: &mut WindowContext| {
3549 view.update(cx, |view, cx| f(view, e, cx)).ok();
3550 }
3551 }
3552
3553 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
3554 pub fn handler_for<V: Render>(
3555 &self,
3556 view: &View<V>,
3557 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
3558 ) -> impl Fn(&mut WindowContext) {
3559 let view = view.downgrade();
3560 move |cx: &mut WindowContext| {
3561 view.update(cx, |view, cx| f(view, cx)).ok();
3562 }
3563 }
3564
3565 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
3566 /// If the callback returns false, the window won't be closed.
3567 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
3568 let mut this = self.to_async();
3569 self.window
3570 .platform_window
3571 .on_should_close(Box::new(move || this.update(|cx| f(cx)).unwrap_or(true)))
3572 }
3573
3574 /// Register an action listener on the window for the next frame. The type of action
3575 /// is determined by the first parameter of the given listener. When the next frame is rendered
3576 /// the listener will be cleared.
3577 ///
3578 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
3579 /// a specific need to register a global listener.
3580 pub fn on_action(
3581 &mut self,
3582 action_type: TypeId,
3583 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
3584 ) {
3585 self.window
3586 .next_frame
3587 .dispatch_tree
3588 .on_action(action_type, Rc::new(listener));
3589 }
3590}
3591
3592#[cfg(target_os = "windows")]
3593impl WindowContext<'_> {
3594 /// Returns the raw HWND handle for the window.
3595 pub fn get_raw_handle(&self) -> windows::Win32::Foundation::HWND {
3596 self.window.platform_window.get_raw_handle()
3597 }
3598}
3599
3600impl Context for WindowContext<'_> {
3601 type Result<T> = T;
3602
3603 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
3604 where
3605 T: 'static,
3606 {
3607 let slot = self.app.entities.reserve();
3608 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
3609 self.entities.insert(slot, model)
3610 }
3611
3612 fn reserve_model<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
3613 self.app.reserve_model()
3614 }
3615
3616 fn insert_model<T: 'static>(
3617 &mut self,
3618 reservation: crate::Reservation<T>,
3619 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
3620 ) -> Self::Result<Model<T>> {
3621 self.app.insert_model(reservation, build_model)
3622 }
3623
3624 fn update_model<T: 'static, R>(
3625 &mut self,
3626 model: &Model<T>,
3627 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
3628 ) -> R {
3629 let mut entity = self.entities.lease(model);
3630 let result = update(
3631 &mut *entity,
3632 &mut ModelContext::new(&mut *self.app, model.downgrade()),
3633 );
3634 self.entities.end_lease(entity);
3635 result
3636 }
3637
3638 fn read_model<T, R>(
3639 &self,
3640 handle: &Model<T>,
3641 read: impl FnOnce(&T, &AppContext) -> R,
3642 ) -> Self::Result<R>
3643 where
3644 T: 'static,
3645 {
3646 let entity = self.entities.read(handle);
3647 read(entity, &*self.app)
3648 }
3649
3650 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
3651 where
3652 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
3653 {
3654 if window == self.window.handle {
3655 let root_view = self.window.root_view.clone().unwrap();
3656 Ok(update(root_view, self))
3657 } else {
3658 window.update(self.app, update)
3659 }
3660 }
3661
3662 fn read_window<T, R>(
3663 &self,
3664 window: &WindowHandle<T>,
3665 read: impl FnOnce(View<T>, &AppContext) -> R,
3666 ) -> Result<R>
3667 where
3668 T: 'static,
3669 {
3670 if window.any_handle == self.window.handle {
3671 let root_view = self
3672 .window
3673 .root_view
3674 .clone()
3675 .unwrap()
3676 .downcast::<T>()
3677 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
3678 Ok(read(root_view, self))
3679 } else {
3680 self.app.read_window(window, read)
3681 }
3682 }
3683}
3684
3685impl VisualContext for WindowContext<'_> {
3686 fn new_view<V>(
3687 &mut self,
3688 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
3689 ) -> Self::Result<View<V>>
3690 where
3691 V: 'static + Render,
3692 {
3693 let slot = self.app.entities.reserve();
3694 let view = View {
3695 model: slot.clone(),
3696 };
3697 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
3698 let entity = build_view_state(&mut cx);
3699 cx.entities.insert(slot, entity);
3700
3701 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
3702 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
3703 cx.new_view_observers.clone().retain(&tid, |observer| {
3704 let any_view = view.clone();
3705 (observer)(any_view, cx);
3706 true
3707 });
3708 }
3709 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
3710
3711 view
3712 }
3713
3714 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
3715 fn update_view<T: 'static, R>(
3716 &mut self,
3717 view: &View<T>,
3718 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
3719 ) -> Self::Result<R> {
3720 let mut lease = self.app.entities.lease(&view.model);
3721 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
3722 let result = update(&mut *lease, &mut cx);
3723 cx.app.entities.end_lease(lease);
3724 result
3725 }
3726
3727 fn replace_root_view<V>(
3728 &mut self,
3729 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
3730 ) -> Self::Result<View<V>>
3731 where
3732 V: 'static + Render,
3733 {
3734 let view = self.new_view(build_view);
3735 self.window.root_view = Some(view.clone().into());
3736 self.refresh();
3737 view
3738 }
3739
3740 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
3741 self.update_view(view, |view, cx| {
3742 view.focus_handle(cx).clone().focus(cx);
3743 })
3744 }
3745
3746 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
3747 where
3748 V: ManagedView,
3749 {
3750 self.update_view(view, |_, cx| cx.emit(DismissEvent))
3751 }
3752}
3753
3754impl<'a> std::ops::Deref for WindowContext<'a> {
3755 type Target = AppContext;
3756
3757 fn deref(&self) -> &Self::Target {
3758 self.app
3759 }
3760}
3761
3762impl<'a> std::ops::DerefMut for WindowContext<'a> {
3763 fn deref_mut(&mut self) -> &mut Self::Target {
3764 self.app
3765 }
3766}
3767
3768impl<'a> Borrow<AppContext> for WindowContext<'a> {
3769 fn borrow(&self) -> &AppContext {
3770 self.app
3771 }
3772}
3773
3774impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
3775 fn borrow_mut(&mut self) -> &mut AppContext {
3776 self.app
3777 }
3778}
3779
3780/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
3781pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
3782 #[doc(hidden)]
3783 fn app_mut(&mut self) -> &mut AppContext {
3784 self.borrow_mut()
3785 }
3786
3787 #[doc(hidden)]
3788 fn app(&self) -> &AppContext {
3789 self.borrow()
3790 }
3791
3792 #[doc(hidden)]
3793 fn window(&self) -> &Window {
3794 self.borrow()
3795 }
3796
3797 #[doc(hidden)]
3798 fn window_mut(&mut self) -> &mut Window {
3799 self.borrow_mut()
3800 }
3801}
3802
3803impl Borrow<Window> for WindowContext<'_> {
3804 fn borrow(&self) -> &Window {
3805 self.window
3806 }
3807}
3808
3809impl BorrowMut<Window> for WindowContext<'_> {
3810 fn borrow_mut(&mut self) -> &mut Window {
3811 self.window
3812 }
3813}
3814
3815impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
3816
3817/// Provides access to application state that is specialized for a particular [`View`].
3818/// Allows you to interact with focus, emit events, etc.
3819/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
3820/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
3821pub struct ViewContext<'a, V> {
3822 window_cx: WindowContext<'a>,
3823 view: &'a View<V>,
3824}
3825
3826impl<V> Borrow<AppContext> for ViewContext<'_, V> {
3827 fn borrow(&self) -> &AppContext {
3828 &*self.window_cx.app
3829 }
3830}
3831
3832impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
3833 fn borrow_mut(&mut self) -> &mut AppContext {
3834 &mut *self.window_cx.app
3835 }
3836}
3837
3838impl<V> Borrow<Window> for ViewContext<'_, V> {
3839 fn borrow(&self) -> &Window {
3840 &*self.window_cx.window
3841 }
3842}
3843
3844impl<V> BorrowMut<Window> for ViewContext<'_, V> {
3845 fn borrow_mut(&mut self) -> &mut Window {
3846 &mut *self.window_cx.window
3847 }
3848}
3849
3850impl<'a, V: 'static> ViewContext<'a, V> {
3851 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
3852 Self {
3853 window_cx: WindowContext::new(app, window),
3854 view,
3855 }
3856 }
3857
3858 /// Get the entity_id of this view.
3859 pub fn entity_id(&self) -> EntityId {
3860 self.view.entity_id()
3861 }
3862
3863 /// Get the view pointer underlying this context.
3864 pub fn view(&self) -> &View<V> {
3865 self.view
3866 }
3867
3868 /// Get the model underlying this view.
3869 pub fn model(&self) -> &Model<V> {
3870 &self.view.model
3871 }
3872
3873 /// Access the underlying window context.
3874 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
3875 &mut self.window_cx
3876 }
3877
3878 /// Sets a given callback to be run on the next frame.
3879 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
3880 where
3881 V: 'static,
3882 {
3883 let view = self.view().clone();
3884 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
3885 }
3886
3887 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
3888 /// that are currently on the stack to be returned to the app.
3889 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
3890 let view = self.view().downgrade();
3891 self.window_cx.defer(move |cx| {
3892 view.update(cx, f).ok();
3893 });
3894 }
3895
3896 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
3897 pub fn observe<V2, E>(
3898 &mut self,
3899 entity: &E,
3900 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
3901 ) -> Subscription
3902 where
3903 V2: 'static,
3904 V: 'static,
3905 E: Entity<V2>,
3906 {
3907 let view = self.view().downgrade();
3908 let entity_id = entity.entity_id();
3909 let entity = entity.downgrade();
3910 let window_handle = self.window.handle;
3911 self.app.new_observer(
3912 entity_id,
3913 Box::new(move |cx| {
3914 window_handle
3915 .update(cx, |_, cx| {
3916 if let Some(handle) = E::upgrade_from(&entity) {
3917 view.update(cx, |this, cx| on_notify(this, handle, cx))
3918 .is_ok()
3919 } else {
3920 false
3921 }
3922 })
3923 .unwrap_or(false)
3924 }),
3925 )
3926 }
3927
3928 /// Subscribe to events emitted by another model or view.
3929 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
3930 /// The callback will be invoked with a reference to the current view, a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a view context for the current view.
3931 pub fn subscribe<V2, E, Evt>(
3932 &mut self,
3933 entity: &E,
3934 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
3935 ) -> Subscription
3936 where
3937 V2: EventEmitter<Evt>,
3938 E: Entity<V2>,
3939 Evt: 'static,
3940 {
3941 let view = self.view().downgrade();
3942 let entity_id = entity.entity_id();
3943 let handle = entity.downgrade();
3944 let window_handle = self.window.handle;
3945 self.app.new_subscription(
3946 entity_id,
3947 (
3948 TypeId::of::<Evt>(),
3949 Box::new(move |event, cx| {
3950 window_handle
3951 .update(cx, |_, cx| {
3952 if let Some(handle) = E::upgrade_from(&handle) {
3953 let event = event.downcast_ref().expect("invalid event type");
3954 view.update(cx, |this, cx| on_event(this, handle, event, cx))
3955 .is_ok()
3956 } else {
3957 false
3958 }
3959 })
3960 .unwrap_or(false)
3961 }),
3962 ),
3963 )
3964 }
3965
3966 /// Register a callback to be invoked when the view is released.
3967 ///
3968 /// The callback receives a handle to the view's window. This handle may be
3969 /// invalid, if the window was closed before the view was released.
3970 pub fn on_release(
3971 &mut self,
3972 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
3973 ) -> Subscription {
3974 let window_handle = self.window.handle;
3975 let (subscription, activate) = self.app.release_listeners.insert(
3976 self.view.model.entity_id,
3977 Box::new(move |this, cx| {
3978 let this = this.downcast_mut().expect("invalid entity type");
3979 on_release(this, window_handle, cx)
3980 }),
3981 );
3982 activate();
3983 subscription
3984 }
3985
3986 /// Register a callback to be invoked when the given Model or View is released.
3987 pub fn observe_release<V2, E>(
3988 &mut self,
3989 entity: &E,
3990 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
3991 ) -> Subscription
3992 where
3993 V: 'static,
3994 V2: 'static,
3995 E: Entity<V2>,
3996 {
3997 let view = self.view().downgrade();
3998 let entity_id = entity.entity_id();
3999 let window_handle = self.window.handle;
4000 let (subscription, activate) = self.app.release_listeners.insert(
4001 entity_id,
4002 Box::new(move |entity, cx| {
4003 let entity = entity.downcast_mut().expect("invalid entity type");
4004 let _ = window_handle.update(cx, |_, cx| {
4005 view.update(cx, |this, cx| on_release(this, entity, cx))
4006 });
4007 }),
4008 );
4009 activate();
4010 subscription
4011 }
4012
4013 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
4014 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
4015 pub fn notify(&mut self) {
4016 self.window_cx.notify(self.view.entity_id());
4017 }
4018
4019 /// Register a callback to be invoked when the window is resized.
4020 pub fn observe_window_bounds(
4021 &mut self,
4022 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4023 ) -> Subscription {
4024 let view = self.view.downgrade();
4025 let (subscription, activate) = self.window.bounds_observers.insert(
4026 (),
4027 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4028 );
4029 activate();
4030 subscription
4031 }
4032
4033 /// Register a callback to be invoked when the window is activated or deactivated.
4034 pub fn observe_window_activation(
4035 &mut self,
4036 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4037 ) -> Subscription {
4038 let view = self.view.downgrade();
4039 let (subscription, activate) = self.window.activation_observers.insert(
4040 (),
4041 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4042 );
4043 activate();
4044 subscription
4045 }
4046
4047 /// Registers a callback to be invoked when the window appearance changes.
4048 pub fn observe_window_appearance(
4049 &mut self,
4050 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4051 ) -> Subscription {
4052 let view = self.view.downgrade();
4053 let (subscription, activate) = self.window.appearance_observers.insert(
4054 (),
4055 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4056 );
4057 activate();
4058 subscription
4059 }
4060
4061 /// Register a callback to be invoked when the window's pending input changes.
4062 pub fn observe_pending_input(
4063 &mut self,
4064 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4065 ) -> Subscription {
4066 let view = self.view.downgrade();
4067 let (subscription, activate) = self.window.pending_input_observers.insert(
4068 (),
4069 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4070 );
4071 activate();
4072 subscription
4073 }
4074
4075 /// Register a listener to be called when the given focus handle receives focus.
4076 /// Returns a subscription and persists until the subscription is dropped.
4077 pub fn on_focus(
4078 &mut self,
4079 handle: &FocusHandle,
4080 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4081 ) -> Subscription {
4082 let view = self.view.downgrade();
4083 let focus_id = handle.id;
4084 let (subscription, activate) =
4085 self.window.new_focus_listener(Box::new(move |event, cx| {
4086 view.update(cx, |view, cx| {
4087 if event.previous_focus_path.last() != Some(&focus_id)
4088 && event.current_focus_path.last() == Some(&focus_id)
4089 {
4090 listener(view, cx)
4091 }
4092 })
4093 .is_ok()
4094 }));
4095 self.app.defer(|_| activate());
4096 subscription
4097 }
4098
4099 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
4100 /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
4101 /// Returns a subscription and persists until the subscription is dropped.
4102 pub fn on_focus_in(
4103 &mut self,
4104 handle: &FocusHandle,
4105 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4106 ) -> Subscription {
4107 let view = self.view.downgrade();
4108 let focus_id = handle.id;
4109 let (subscription, activate) =
4110 self.window.new_focus_listener(Box::new(move |event, cx| {
4111 view.update(cx, |view, cx| {
4112 if !event.previous_focus_path.contains(&focus_id)
4113 && event.current_focus_path.contains(&focus_id)
4114 {
4115 listener(view, cx)
4116 }
4117 })
4118 .is_ok()
4119 }));
4120 self.app.defer(move |_| activate());
4121 subscription
4122 }
4123
4124 /// Register a listener to be called when the given focus handle loses focus.
4125 /// Returns a subscription and persists until the subscription is dropped.
4126 pub fn on_blur(
4127 &mut self,
4128 handle: &FocusHandle,
4129 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4130 ) -> Subscription {
4131 let view = self.view.downgrade();
4132 let focus_id = handle.id;
4133 let (subscription, activate) =
4134 self.window.new_focus_listener(Box::new(move |event, cx| {
4135 view.update(cx, |view, cx| {
4136 if event.previous_focus_path.last() == Some(&focus_id)
4137 && event.current_focus_path.last() != Some(&focus_id)
4138 {
4139 listener(view, cx)
4140 }
4141 })
4142 .is_ok()
4143 }));
4144 self.app.defer(move |_| activate());
4145 subscription
4146 }
4147
4148 /// Register a listener to be called when nothing in the window has focus.
4149 /// This typically happens when the node that was focused is removed from the tree,
4150 /// and this callback lets you chose a default place to restore the users focus.
4151 /// Returns a subscription and persists until the subscription is dropped.
4152 pub fn on_focus_lost(
4153 &mut self,
4154 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4155 ) -> Subscription {
4156 let view = self.view.downgrade();
4157 let (subscription, activate) = self.window.focus_lost_listeners.insert(
4158 (),
4159 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
4160 );
4161 activate();
4162 subscription
4163 }
4164
4165 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
4166 /// Returns a subscription and persists until the subscription is dropped.
4167 pub fn on_focus_out(
4168 &mut self,
4169 handle: &FocusHandle,
4170 mut listener: impl FnMut(&mut V, FocusOutEvent, &mut ViewContext<V>) + 'static,
4171 ) -> Subscription {
4172 let view = self.view.downgrade();
4173 let focus_id = handle.id;
4174 let (subscription, activate) =
4175 self.window.new_focus_listener(Box::new(move |event, cx| {
4176 view.update(cx, |view, cx| {
4177 if let Some(blurred_id) = event.previous_focus_path.last().copied() {
4178 if event.previous_focus_path.contains(&focus_id)
4179 && !event.current_focus_path.contains(&focus_id)
4180 {
4181 let event = FocusOutEvent {
4182 blurred: WeakFocusHandle {
4183 id: blurred_id,
4184 handles: Arc::downgrade(&cx.window.focus_handles),
4185 },
4186 };
4187 listener(view, event, cx)
4188 }
4189 }
4190 })
4191 .is_ok()
4192 }));
4193 self.app.defer(move |_| activate());
4194 subscription
4195 }
4196
4197 /// Schedule a future to be run asynchronously.
4198 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
4199 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
4200 /// The returned future will be polled on the main thread.
4201 pub fn spawn<Fut, R>(
4202 &mut self,
4203 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
4204 ) -> Task<R>
4205 where
4206 R: 'static,
4207 Fut: Future<Output = R> + 'static,
4208 {
4209 let view = self.view().downgrade();
4210 self.window_cx.spawn(|cx| f(view, cx))
4211 }
4212
4213 /// Register a callback to be invoked when the given global state changes.
4214 pub fn observe_global<G: Global>(
4215 &mut self,
4216 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
4217 ) -> Subscription {
4218 let window_handle = self.window.handle;
4219 let view = self.view().downgrade();
4220 let (subscription, activate) = self.global_observers.insert(
4221 TypeId::of::<G>(),
4222 Box::new(move |cx| {
4223 window_handle
4224 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
4225 .unwrap_or(false)
4226 }),
4227 );
4228 self.app.defer(move |_| activate());
4229 subscription
4230 }
4231
4232 /// Register a callback to be invoked when the given Action type is dispatched to the window.
4233 pub fn on_action(
4234 &mut self,
4235 action_type: TypeId,
4236 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
4237 ) {
4238 let handle = self.view().clone();
4239 self.window_cx
4240 .on_action(action_type, move |action, phase, cx| {
4241 handle.update(cx, |view, cx| {
4242 listener(view, action, phase, cx);
4243 })
4244 });
4245 }
4246
4247 /// Emit an event to be handled by any other views that have subscribed via [ViewContext::subscribe].
4248 pub fn emit<Evt>(&mut self, event: Evt)
4249 where
4250 Evt: 'static,
4251 V: EventEmitter<Evt>,
4252 {
4253 let emitter = self.view.model.entity_id;
4254 self.app.push_effect(Effect::Emit {
4255 emitter,
4256 event_type: TypeId::of::<Evt>(),
4257 event: Box::new(event),
4258 });
4259 }
4260
4261 /// Move focus to the current view, assuming it implements [`FocusableView`].
4262 pub fn focus_self(&mut self)
4263 where
4264 V: FocusableView,
4265 {
4266 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
4267 }
4268
4269 /// Convenience method for accessing view state in an event callback.
4270 ///
4271 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
4272 /// but it's often useful to be able to access view state in these
4273 /// callbacks. This method provides a convenient way to do so.
4274 pub fn listener<E>(
4275 &self,
4276 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
4277 ) -> impl Fn(&E, &mut WindowContext) + 'static {
4278 let view = self.view().downgrade();
4279 move |e: &E, cx: &mut WindowContext| {
4280 view.update(cx, |view, cx| f(view, e, cx)).ok();
4281 }
4282 }
4283}
4284
4285impl<V> Context for ViewContext<'_, V> {
4286 type Result<U> = U;
4287
4288 fn new_model<T: 'static>(
4289 &mut self,
4290 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
4291 ) -> Model<T> {
4292 self.window_cx.new_model(build_model)
4293 }
4294
4295 fn reserve_model<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
4296 self.window_cx.reserve_model()
4297 }
4298
4299 fn insert_model<T: 'static>(
4300 &mut self,
4301 reservation: crate::Reservation<T>,
4302 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
4303 ) -> Self::Result<Model<T>> {
4304 self.window_cx.insert_model(reservation, build_model)
4305 }
4306
4307 fn update_model<T: 'static, R>(
4308 &mut self,
4309 model: &Model<T>,
4310 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
4311 ) -> R {
4312 self.window_cx.update_model(model, update)
4313 }
4314
4315 fn read_model<T, R>(
4316 &self,
4317 handle: &Model<T>,
4318 read: impl FnOnce(&T, &AppContext) -> R,
4319 ) -> Self::Result<R>
4320 where
4321 T: 'static,
4322 {
4323 self.window_cx.read_model(handle, read)
4324 }
4325
4326 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
4327 where
4328 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
4329 {
4330 self.window_cx.update_window(window, update)
4331 }
4332
4333 fn read_window<T, R>(
4334 &self,
4335 window: &WindowHandle<T>,
4336 read: impl FnOnce(View<T>, &AppContext) -> R,
4337 ) -> Result<R>
4338 where
4339 T: 'static,
4340 {
4341 self.window_cx.read_window(window, read)
4342 }
4343}
4344
4345impl<V: 'static> VisualContext for ViewContext<'_, V> {
4346 fn new_view<W: Render + 'static>(
4347 &mut self,
4348 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
4349 ) -> Self::Result<View<W>> {
4350 self.window_cx.new_view(build_view_state)
4351 }
4352
4353 fn update_view<V2: 'static, R>(
4354 &mut self,
4355 view: &View<V2>,
4356 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
4357 ) -> Self::Result<R> {
4358 self.window_cx.update_view(view, update)
4359 }
4360
4361 fn replace_root_view<W>(
4362 &mut self,
4363 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
4364 ) -> Self::Result<View<W>>
4365 where
4366 W: 'static + Render,
4367 {
4368 self.window_cx.replace_root_view(build_view)
4369 }
4370
4371 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
4372 self.window_cx.focus_view(view)
4373 }
4374
4375 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
4376 self.window_cx.dismiss_view(view)
4377 }
4378}
4379
4380impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
4381 type Target = WindowContext<'a>;
4382
4383 fn deref(&self) -> &Self::Target {
4384 &self.window_cx
4385 }
4386}
4387
4388impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
4389 fn deref_mut(&mut self) -> &mut Self::Target {
4390 &mut self.window_cx
4391 }
4392}
4393
4394// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4395slotmap::new_key_type! {
4396 /// A unique identifier for a window.
4397 pub struct WindowId;
4398}
4399
4400impl WindowId {
4401 /// Converts this window ID to a `u64`.
4402 pub fn as_u64(&self) -> u64 {
4403 self.0.as_ffi()
4404 }
4405}
4406
4407/// A handle to a window with a specific root view type.
4408/// Note that this does not keep the window alive on its own.
4409#[derive(Deref, DerefMut)]
4410pub struct WindowHandle<V> {
4411 #[deref]
4412 #[deref_mut]
4413 pub(crate) any_handle: AnyWindowHandle,
4414 state_type: PhantomData<V>,
4415}
4416
4417impl<V: 'static + Render> WindowHandle<V> {
4418 /// Creates a new handle from a window ID.
4419 /// This does not check if the root type of the window is `V`.
4420 pub fn new(id: WindowId) -> Self {
4421 WindowHandle {
4422 any_handle: AnyWindowHandle {
4423 id,
4424 state_type: TypeId::of::<V>(),
4425 },
4426 state_type: PhantomData,
4427 }
4428 }
4429
4430 /// Get the root view out of this window.
4431 ///
4432 /// This will fail if the window is closed or if the root view's type does not match `V`.
4433 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
4434 where
4435 C: Context,
4436 {
4437 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
4438 root_view
4439 .downcast::<V>()
4440 .map_err(|_| anyhow!("the type of the window's root view has changed"))
4441 }))
4442 }
4443
4444 /// Updates the root view of this window.
4445 ///
4446 /// This will fail if the window has been closed or if the root view's type does not match
4447 pub fn update<C, R>(
4448 &self,
4449 cx: &mut C,
4450 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
4451 ) -> Result<R>
4452 where
4453 C: Context,
4454 {
4455 cx.update_window(self.any_handle, |root_view, cx| {
4456 let view = root_view
4457 .downcast::<V>()
4458 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4459 Ok(cx.update_view(&view, update))
4460 })?
4461 }
4462
4463 /// Read the root view out of this window.
4464 ///
4465 /// This will fail if the window is closed or if the root view's type does not match `V`.
4466 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
4467 let x = cx
4468 .windows
4469 .get(self.id)
4470 .and_then(|window| {
4471 window
4472 .as_ref()
4473 .and_then(|window| window.root_view.clone())
4474 .map(|root_view| root_view.downcast::<V>())
4475 })
4476 .ok_or_else(|| anyhow!("window not found"))?
4477 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4478
4479 Ok(x.read(cx))
4480 }
4481
4482 /// Read the root view out of this window, with a callback
4483 ///
4484 /// This will fail if the window is closed or if the root view's type does not match `V`.
4485 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
4486 where
4487 C: Context,
4488 {
4489 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4490 }
4491
4492 /// Read the root view pointer off of this window.
4493 ///
4494 /// This will fail if the window is closed or if the root view's type does not match `V`.
4495 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
4496 where
4497 C: Context,
4498 {
4499 cx.read_window(self, |root_view, _cx| root_view.clone())
4500 }
4501
4502 /// Check if this window is 'active'.
4503 ///
4504 /// Will return `None` if the window is closed or currently
4505 /// borrowed.
4506 pub fn is_active(&self, cx: &mut AppContext) -> Option<bool> {
4507 cx.update_window(self.any_handle, |_, cx| cx.is_window_active())
4508 .ok()
4509 }
4510}
4511
4512impl<V> Copy for WindowHandle<V> {}
4513
4514impl<V> Clone for WindowHandle<V> {
4515 fn clone(&self) -> Self {
4516 *self
4517 }
4518}
4519
4520impl<V> PartialEq for WindowHandle<V> {
4521 fn eq(&self, other: &Self) -> bool {
4522 self.any_handle == other.any_handle
4523 }
4524}
4525
4526impl<V> Eq for WindowHandle<V> {}
4527
4528impl<V> Hash for WindowHandle<V> {
4529 fn hash<H: Hasher>(&self, state: &mut H) {
4530 self.any_handle.hash(state);
4531 }
4532}
4533
4534impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
4535 fn from(val: WindowHandle<V>) -> Self {
4536 val.any_handle
4537 }
4538}
4539
4540unsafe impl<V> Send for WindowHandle<V> {}
4541unsafe impl<V> Sync for WindowHandle<V> {}
4542
4543/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
4544#[derive(Copy, Clone, PartialEq, Eq, Hash)]
4545pub struct AnyWindowHandle {
4546 pub(crate) id: WindowId,
4547 state_type: TypeId,
4548}
4549
4550impl AnyWindowHandle {
4551 /// Get the ID of this window.
4552 pub fn window_id(&self) -> WindowId {
4553 self.id
4554 }
4555
4556 /// Attempt to convert this handle to a window handle with a specific root view type.
4557 /// If the types do not match, this will return `None`.
4558 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
4559 if TypeId::of::<T>() == self.state_type {
4560 Some(WindowHandle {
4561 any_handle: *self,
4562 state_type: PhantomData,
4563 })
4564 } else {
4565 None
4566 }
4567 }
4568
4569 /// Updates the state of the root view of this window.
4570 ///
4571 /// This will fail if the window has been closed.
4572 pub fn update<C, R>(
4573 self,
4574 cx: &mut C,
4575 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
4576 ) -> Result<R>
4577 where
4578 C: Context,
4579 {
4580 cx.update_window(self, update)
4581 }
4582
4583 /// Read the state of the root view of this window.
4584 ///
4585 /// This will fail if the window has been closed.
4586 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
4587 where
4588 C: Context,
4589 T: 'static,
4590 {
4591 let view = self
4592 .downcast::<T>()
4593 .context("the type of the window's root view has changed")?;
4594
4595 cx.read_window(&view, read)
4596 }
4597}
4598
4599/// An identifier for an [`Element`](crate::Element).
4600///
4601/// Can be constructed with a string, a number, or both, as well
4602/// as other internal representations.
4603#[derive(Clone, Debug, Eq, PartialEq, Hash)]
4604pub enum ElementId {
4605 /// The ID of a View element
4606 View(EntityId),
4607 /// An integer ID.
4608 Integer(usize),
4609 /// A string based ID.
4610 Name(SharedString),
4611 /// A UUID.
4612 Uuid(Uuid),
4613 /// An ID that's equated with a focus handle.
4614 FocusHandle(FocusId),
4615 /// A combination of a name and an integer.
4616 NamedInteger(SharedString, usize),
4617}
4618
4619impl Display for ElementId {
4620 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4621 match self {
4622 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
4623 ElementId::Integer(ix) => write!(f, "{}", ix)?,
4624 ElementId::Name(name) => write!(f, "{}", name)?,
4625 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
4626 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
4627 ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
4628 }
4629
4630 Ok(())
4631 }
4632}
4633
4634impl TryInto<SharedString> for ElementId {
4635 type Error = anyhow::Error;
4636
4637 fn try_into(self) -> anyhow::Result<SharedString> {
4638 if let ElementId::Name(name) = self {
4639 Ok(name)
4640 } else {
4641 Err(anyhow!("element id is not string"))
4642 }
4643 }
4644}
4645
4646impl From<usize> for ElementId {
4647 fn from(id: usize) -> Self {
4648 ElementId::Integer(id)
4649 }
4650}
4651
4652impl From<i32> for ElementId {
4653 fn from(id: i32) -> Self {
4654 Self::Integer(id as usize)
4655 }
4656}
4657
4658impl From<SharedString> for ElementId {
4659 fn from(name: SharedString) -> Self {
4660 ElementId::Name(name)
4661 }
4662}
4663
4664impl From<&'static str> for ElementId {
4665 fn from(name: &'static str) -> Self {
4666 ElementId::Name(name.into())
4667 }
4668}
4669
4670impl<'a> From<&'a FocusHandle> for ElementId {
4671 fn from(handle: &'a FocusHandle) -> Self {
4672 ElementId::FocusHandle(handle.id)
4673 }
4674}
4675
4676impl From<(&'static str, EntityId)> for ElementId {
4677 fn from((name, id): (&'static str, EntityId)) -> Self {
4678 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
4679 }
4680}
4681
4682impl From<(&'static str, usize)> for ElementId {
4683 fn from((name, id): (&'static str, usize)) -> Self {
4684 ElementId::NamedInteger(name.into(), id)
4685 }
4686}
4687
4688impl From<(&'static str, u64)> for ElementId {
4689 fn from((name, id): (&'static str, u64)) -> Self {
4690 ElementId::NamedInteger(name.into(), id as usize)
4691 }
4692}
4693
4694impl From<Uuid> for ElementId {
4695 fn from(value: Uuid) -> Self {
4696 Self::Uuid(value)
4697 }
4698}
4699
4700impl From<(&'static str, u32)> for ElementId {
4701 fn from((name, id): (&'static str, u32)) -> Self {
4702 ElementId::NamedInteger(name.into(), id as usize)
4703 }
4704}
4705
4706/// A rectangle to be rendered in the window at the given position and size.
4707/// Passed as an argument [`WindowContext::paint_quad`].
4708#[derive(Clone)]
4709pub struct PaintQuad {
4710 /// The bounds of the quad within the window.
4711 pub bounds: Bounds<Pixels>,
4712 /// The radii of the quad's corners.
4713 pub corner_radii: Corners<Pixels>,
4714 /// The background color of the quad.
4715 pub background: Hsla,
4716 /// The widths of the quad's borders.
4717 pub border_widths: Edges<Pixels>,
4718 /// The color of the quad's borders.
4719 pub border_color: Hsla,
4720}
4721
4722impl PaintQuad {
4723 /// Sets the corner radii of the quad.
4724 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
4725 PaintQuad {
4726 corner_radii: corner_radii.into(),
4727 ..self
4728 }
4729 }
4730
4731 /// Sets the border widths of the quad.
4732 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
4733 PaintQuad {
4734 border_widths: border_widths.into(),
4735 ..self
4736 }
4737 }
4738
4739 /// Sets the border color of the quad.
4740 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
4741 PaintQuad {
4742 border_color: border_color.into(),
4743 ..self
4744 }
4745 }
4746
4747 /// Sets the background color of the quad.
4748 pub fn background(self, background: impl Into<Hsla>) -> Self {
4749 PaintQuad {
4750 background: background.into(),
4751 ..self
4752 }
4753 }
4754}
4755
4756/// Creates a quad with the given parameters.
4757pub fn quad(
4758 bounds: Bounds<Pixels>,
4759 corner_radii: impl Into<Corners<Pixels>>,
4760 background: impl Into<Hsla>,
4761 border_widths: impl Into<Edges<Pixels>>,
4762 border_color: impl Into<Hsla>,
4763) -> PaintQuad {
4764 PaintQuad {
4765 bounds,
4766 corner_radii: corner_radii.into(),
4767 background: background.into(),
4768 border_widths: border_widths.into(),
4769 border_color: border_color.into(),
4770 }
4771}
4772
4773/// Creates a filled quad with the given bounds and background color.
4774pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
4775 PaintQuad {
4776 bounds: bounds.into(),
4777 corner_radii: (0.).into(),
4778 background: background.into(),
4779 border_widths: (0.).into(),
4780 border_color: transparent_black(),
4781 }
4782}
4783
4784/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
4785pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
4786 PaintQuad {
4787 bounds: bounds.into(),
4788 corner_radii: (0.).into(),
4789 background: transparent_black(),
4790 border_widths: (1.).into(),
4791 border_color: border_color.into(),
4792 }
4793}