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