1use crate::{
2 point, prelude::*, px, size, transparent_black, Action, AnyDrag, AnyElement, AnyTooltip,
3 AnyView, AppContext, Arena, Asset, AsyncWindowContext, AvailableSpace, Background, Bounds,
4 BoxShadow, Context, Corners, CursorStyle, Decorations, DevicePixels, DispatchActionListener,
5 DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter,
6 FileDropEvent, Flatten, FontId, GPUSpecs, Global, GlobalElementId, GlyphId, Hsla, InputHandler,
7 IsZero, KeyBinding, KeyContext, KeyDownEvent, KeyEvent, Keystroke, KeystrokeEvent,
8 KeystrokeObserver, LayoutId, LineLayoutIndex, Model, ModelContext, Modifiers,
9 ModifiersChangedEvent, MonochromeSprite, MouseButton, MouseEvent, MouseMoveEvent, MouseUpEvent,
10 Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput, PlatformInputHandler,
11 PlatformWindow, Point, PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams,
12 RenderImage, RenderImageParams, RenderSvgParams, Replay, ResizeEdge, ScaledPixels, Scene,
13 Shadow, SharedString, Size, StrikethroughStyle, Style, SubscriberSet, Subscription,
14 TaffyLayoutEngine, Task, TextStyle, TextStyleRefinement, TransformationMatrix, Underline,
15 UnderlineStyle, View, VisualContext, WeakView, WindowAppearance, WindowBackgroundAppearance,
16 WindowBounds, WindowControls, WindowDecorations, WindowOptions, WindowParams, WindowTextSystem,
17 SUBPIXEL_VARIANTS,
18};
19use anyhow::{anyhow, Context as _, Result};
20use collections::{FxHashMap, FxHashSet};
21use derive_more::{Deref, DerefMut};
22use futures::channel::oneshot;
23use futures::FutureExt;
24#[cfg(target_os = "macos")]
25use media::core_video::CVImageBuffer;
26use parking_lot::RwLock;
27use refineable::Refineable;
28use slotmap::SlotMap;
29use smallvec::SmallVec;
30use std::{
31 any::{Any, TypeId},
32 borrow::{Borrow, BorrowMut, Cow},
33 cell::{Cell, RefCell},
34 cmp,
35 fmt::{Debug, Display},
36 future::Future,
37 hash::{Hash, Hasher},
38 marker::PhantomData,
39 mem,
40 ops::Range,
41 rc::Rc,
42 sync::{
43 atomic::{AtomicUsize, Ordering::SeqCst},
44 Arc, Weak,
45 },
46 time::{Duration, Instant},
47};
48use util::post_inc;
49use util::{measure, ResultExt};
50use uuid::Uuid;
51
52mod prompts;
53
54pub use prompts::*;
55
56pub(crate) const DEFAULT_WINDOW_SIZE: Size<Pixels> = size(px(1024.), px(700.));
57
58/// Represents the two different phases when dispatching events.
59#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
60pub enum DispatchPhase {
61 /// After the capture phase comes the bubble phase, in which mouse event listeners are
62 /// invoked front to back and keyboard event listeners are invoked from the focused element
63 /// to the root of the element tree. This is the phase you'll most commonly want to use when
64 /// registering event listeners.
65 #[default]
66 Bubble,
67 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
68 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
69 /// is used for special purposes such as clearing the "pressed" state for click events. If
70 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
71 /// outside of the immediate region may rely on detecting non-local events during this phase.
72 Capture,
73}
74
75impl DispatchPhase {
76 /// Returns true if this represents the "bubble" phase.
77 pub fn bubble(self) -> bool {
78 self == DispatchPhase::Bubble
79 }
80
81 /// Returns true if this represents the "capture" phase.
82 pub fn capture(self) -> bool {
83 self == DispatchPhase::Capture
84 }
85}
86
87type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
88
89type AnyWindowFocusListener =
90 Box<dyn FnMut(&WindowFocusEvent, &mut WindowContext) -> bool + 'static>;
91
92struct WindowFocusEvent {
93 previous_focus_path: SmallVec<[FocusId; 8]>,
94 current_focus_path: SmallVec<[FocusId; 8]>,
95}
96
97impl WindowFocusEvent {
98 pub fn is_focus_in(&self, focus_id: FocusId) -> bool {
99 !self.previous_focus_path.contains(&focus_id) && self.current_focus_path.contains(&focus_id)
100 }
101
102 pub fn is_focus_out(&self, focus_id: FocusId) -> bool {
103 self.previous_focus_path.contains(&focus_id) && !self.current_focus_path.contains(&focus_id)
104 }
105}
106
107/// This is provided when subscribing for `ViewContext::on_focus_out` events.
108pub struct FocusOutEvent {
109 /// A weak focus handle representing what was blurred.
110 pub blurred: WeakFocusHandle,
111}
112
113slotmap::new_key_type! {
114 /// A globally unique identifier for a focusable element.
115 pub struct FocusId;
116}
117
118thread_local! {
119 /// 8MB wasn't quite enough...
120 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(32 * 1024 * 1024));
121}
122
123impl FocusId {
124 /// Obtains whether the element associated with this handle is currently focused.
125 pub fn is_focused(&self, cx: &WindowContext) -> bool {
126 cx.window.focus == Some(*self)
127 }
128
129 /// Obtains whether the element associated with this handle contains the focused
130 /// element or is itself focused.
131 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
132 cx.focused()
133 .map_or(false, |focused| self.contains(focused.id, cx))
134 }
135
136 /// Obtains whether the element associated with this handle is contained within the
137 /// focused element or is itself focused.
138 pub fn within_focused(&self, cx: &WindowContext) -> bool {
139 let focused = cx.focused();
140 focused.map_or(false, |focused| focused.id.contains(*self, cx))
141 }
142
143 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
144 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
145 cx.window
146 .rendered_frame
147 .dispatch_tree
148 .focus_contains(*self, other)
149 }
150}
151
152/// A handle which can be used to track and manipulate the focused element in a window.
153pub struct FocusHandle {
154 pub(crate) id: FocusId,
155 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
156}
157
158impl std::fmt::Debug for FocusHandle {
159 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
160 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
161 }
162}
163
164impl FocusHandle {
165 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
166 let id = handles.write().insert(AtomicUsize::new(1));
167 Self {
168 id,
169 handles: handles.clone(),
170 }
171 }
172
173 pub(crate) fn for_id(
174 id: FocusId,
175 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
176 ) -> Option<Self> {
177 let lock = handles.read();
178 let ref_count = lock.get(id)?;
179 if ref_count.load(SeqCst) == 0 {
180 None
181 } else {
182 ref_count.fetch_add(1, SeqCst);
183 Some(Self {
184 id,
185 handles: handles.clone(),
186 })
187 }
188 }
189
190 /// Converts this focus handle into a weak variant, which does not prevent it from being released.
191 pub fn downgrade(&self) -> WeakFocusHandle {
192 WeakFocusHandle {
193 id: self.id,
194 handles: Arc::downgrade(&self.handles),
195 }
196 }
197
198 /// Moves the focus to the element associated with this handle.
199 pub fn focus(&self, cx: &mut WindowContext) {
200 cx.focus(self)
201 }
202
203 /// Obtains whether the element associated with this handle is currently focused.
204 pub fn is_focused(&self, cx: &WindowContext) -> bool {
205 self.id.is_focused(cx)
206 }
207
208 /// Obtains whether the element associated with this handle contains the focused
209 /// element or is itself focused.
210 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
211 self.id.contains_focused(cx)
212 }
213
214 /// Obtains whether the element associated with this handle is contained within the
215 /// focused element or is itself focused.
216 pub fn within_focused(&self, cx: &WindowContext) -> bool {
217 self.id.within_focused(cx)
218 }
219
220 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
221 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
222 self.id.contains(other.id, cx)
223 }
224
225 /// Dispatch an action on the element that rendered this focus handle
226 pub fn dispatch_action(&self, action: &dyn Action, cx: &mut WindowContext) {
227 if let Some(node_id) = cx
228 .window
229 .rendered_frame
230 .dispatch_tree
231 .focusable_node_id(self.id)
232 {
233 cx.dispatch_action_on_node(node_id, action)
234 }
235 }
236}
237
238impl Clone for FocusHandle {
239 fn clone(&self) -> Self {
240 Self::for_id(self.id, &self.handles).unwrap()
241 }
242}
243
244impl PartialEq for FocusHandle {
245 fn eq(&self, other: &Self) -> bool {
246 self.id == other.id
247 }
248}
249
250impl Eq for FocusHandle {}
251
252impl Drop for FocusHandle {
253 fn drop(&mut self) {
254 self.handles
255 .read()
256 .get(self.id)
257 .unwrap()
258 .fetch_sub(1, SeqCst);
259 }
260}
261
262/// A weak reference to a focus handle.
263#[derive(Clone, Debug)]
264pub struct WeakFocusHandle {
265 pub(crate) id: FocusId,
266 handles: Weak<RwLock<SlotMap<FocusId, AtomicUsize>>>,
267}
268
269impl WeakFocusHandle {
270 /// Attempts to upgrade the [WeakFocusHandle] to a [FocusHandle].
271 pub fn upgrade(&self) -> Option<FocusHandle> {
272 let handles = self.handles.upgrade()?;
273 FocusHandle::for_id(self.id, &handles)
274 }
275}
276
277impl PartialEq for WeakFocusHandle {
278 fn eq(&self, other: &WeakFocusHandle) -> bool {
279 self.id == other.id
280 }
281}
282
283impl Eq for WeakFocusHandle {}
284
285impl PartialEq<FocusHandle> for WeakFocusHandle {
286 fn eq(&self, other: &FocusHandle) -> bool {
287 self.id == other.id
288 }
289}
290
291impl PartialEq<WeakFocusHandle> for FocusHandle {
292 fn eq(&self, other: &WeakFocusHandle) -> bool {
293 self.id == other.id
294 }
295}
296
297/// FocusableView allows users of your view to easily
298/// focus it (using cx.focus_view(view))
299pub trait FocusableView: 'static + Render {
300 /// Returns the focus handle associated with this view.
301 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
302}
303
304/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
305/// where the lifecycle of the view is handled by another view.
306pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
307
308impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
309
310/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
311pub struct DismissEvent;
312
313type FrameCallback = Box<dyn FnOnce(&mut WindowContext)>;
314
315pub(crate) type AnyMouseListener =
316 Box<dyn FnMut(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
317
318#[derive(Clone)]
319pub(crate) struct CursorStyleRequest {
320 pub(crate) hitbox_id: HitboxId,
321 pub(crate) style: CursorStyle,
322}
323
324/// An identifier for a [Hitbox].
325#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
326pub struct HitboxId(usize);
327
328impl HitboxId {
329 /// Checks if the hitbox with this id is currently hovered.
330 pub fn is_hovered(&self, cx: &WindowContext) -> bool {
331 cx.window.mouse_hit_test.0.contains(self)
332 }
333}
334
335/// A rectangular region that potentially blocks hitboxes inserted prior.
336/// See [WindowContext::insert_hitbox] for more details.
337#[derive(Clone, Debug, Deref)]
338pub struct Hitbox {
339 /// A unique identifier for the hitbox.
340 pub id: HitboxId,
341 /// The bounds of the hitbox.
342 #[deref]
343 pub bounds: Bounds<Pixels>,
344 /// The content mask when the hitbox was inserted.
345 pub content_mask: ContentMask<Pixels>,
346 /// Whether the hitbox occludes other hitboxes inserted prior.
347 pub opaque: bool,
348}
349
350impl Hitbox {
351 /// Checks if the hitbox is currently hovered.
352 pub fn is_hovered(&self, cx: &WindowContext) -> bool {
353 self.id.is_hovered(cx)
354 }
355}
356
357#[derive(Default, Eq, PartialEq)]
358pub(crate) struct HitTest(SmallVec<[HitboxId; 8]>);
359
360/// An identifier for a tooltip.
361#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
362pub struct TooltipId(usize);
363
364impl TooltipId {
365 /// Checks if the tooltip is currently hovered.
366 pub fn is_hovered(&self, cx: &WindowContext) -> bool {
367 cx.window
368 .tooltip_bounds
369 .as_ref()
370 .map_or(false, |tooltip_bounds| {
371 tooltip_bounds.id == *self && tooltip_bounds.bounds.contains(&cx.mouse_position())
372 })
373 }
374}
375
376pub(crate) struct TooltipBounds {
377 id: TooltipId,
378 bounds: Bounds<Pixels>,
379}
380
381#[derive(Clone)]
382pub(crate) struct TooltipRequest {
383 id: TooltipId,
384 tooltip: AnyTooltip,
385}
386
387pub(crate) struct DeferredDraw {
388 priority: usize,
389 parent_node: DispatchNodeId,
390 element_id_stack: SmallVec<[ElementId; 32]>,
391 text_style_stack: Vec<TextStyleRefinement>,
392 element: Option<AnyElement>,
393 absolute_offset: Point<Pixels>,
394 prepaint_range: Range<PrepaintStateIndex>,
395 paint_range: Range<PaintIndex>,
396}
397
398pub(crate) struct Frame {
399 pub(crate) focus: Option<FocusId>,
400 pub(crate) window_active: bool,
401 pub(crate) element_states: FxHashMap<(GlobalElementId, TypeId), ElementStateBox>,
402 accessed_element_states: Vec<(GlobalElementId, TypeId)>,
403 pub(crate) mouse_listeners: Vec<Option<AnyMouseListener>>,
404 pub(crate) dispatch_tree: DispatchTree,
405 pub(crate) scene: Scene,
406 pub(crate) hitboxes: Vec<Hitbox>,
407 pub(crate) deferred_draws: Vec<DeferredDraw>,
408 pub(crate) input_handlers: Vec<Option<PlatformInputHandler>>,
409 pub(crate) tooltip_requests: Vec<Option<TooltipRequest>>,
410 pub(crate) cursor_styles: Vec<CursorStyleRequest>,
411 #[cfg(any(test, feature = "test-support"))]
412 pub(crate) debug_bounds: FxHashMap<String, Bounds<Pixels>>,
413}
414
415#[derive(Clone, Default)]
416pub(crate) struct PrepaintStateIndex {
417 hitboxes_index: usize,
418 tooltips_index: usize,
419 deferred_draws_index: usize,
420 dispatch_tree_index: usize,
421 accessed_element_states_index: usize,
422 line_layout_index: LineLayoutIndex,
423}
424
425#[derive(Clone, Default)]
426pub(crate) struct PaintIndex {
427 scene_index: usize,
428 mouse_listeners_index: usize,
429 input_handlers_index: usize,
430 cursor_styles_index: usize,
431 accessed_element_states_index: usize,
432 line_layout_index: LineLayoutIndex,
433}
434
435impl Frame {
436 pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
437 Frame {
438 focus: None,
439 window_active: false,
440 element_states: FxHashMap::default(),
441 accessed_element_states: Vec::new(),
442 mouse_listeners: Vec::new(),
443 dispatch_tree,
444 scene: Scene::default(),
445 hitboxes: Vec::new(),
446 deferred_draws: Vec::new(),
447 input_handlers: Vec::new(),
448 tooltip_requests: Vec::new(),
449 cursor_styles: Vec::new(),
450
451 #[cfg(any(test, feature = "test-support"))]
452 debug_bounds: FxHashMap::default(),
453 }
454 }
455
456 pub(crate) fn clear(&mut self) {
457 self.element_states.clear();
458 self.accessed_element_states.clear();
459 self.mouse_listeners.clear();
460 self.dispatch_tree.clear();
461 self.scene.clear();
462 self.input_handlers.clear();
463 self.tooltip_requests.clear();
464 self.cursor_styles.clear();
465 self.hitboxes.clear();
466 self.deferred_draws.clear();
467 self.focus = None;
468 }
469
470 pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
471 let mut hit_test = HitTest::default();
472 for hitbox in self.hitboxes.iter().rev() {
473 let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
474 if bounds.contains(&position) {
475 hit_test.0.push(hitbox.id);
476 if hitbox.opaque {
477 break;
478 }
479 }
480 }
481 hit_test
482 }
483
484 pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
485 self.focus
486 .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
487 .unwrap_or_default()
488 }
489
490 pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
491 for element_state_key in &self.accessed_element_states {
492 if let Some((element_state_key, element_state)) =
493 prev_frame.element_states.remove_entry(element_state_key)
494 {
495 self.element_states.insert(element_state_key, element_state);
496 }
497 }
498
499 self.scene.finish();
500 }
501}
502
503// Holds the state for a specific window.
504#[doc(hidden)]
505pub struct Window {
506 pub(crate) handle: AnyWindowHandle,
507 pub(crate) removed: bool,
508 pub(crate) platform_window: Box<dyn PlatformWindow>,
509 display_id: Option<DisplayId>,
510 sprite_atlas: Arc<dyn PlatformAtlas>,
511 text_system: Arc<WindowTextSystem>,
512 rem_size: Pixels,
513 /// The stack of override values for the window's rem size.
514 ///
515 /// This is used by `with_rem_size` to allow rendering an element tree with
516 /// a given rem size.
517 rem_size_override_stack: SmallVec<[Pixels; 8]>,
518 pub(crate) viewport_size: Size<Pixels>,
519 layout_engine: Option<TaffyLayoutEngine>,
520 pub(crate) root_view: Option<AnyView>,
521 pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
522 pub(crate) text_style_stack: Vec<TextStyleRefinement>,
523 pub(crate) element_offset_stack: Vec<Point<Pixels>>,
524 pub(crate) element_opacity: Option<f32>,
525 pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
526 pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
527 pub(crate) rendered_frame: Frame,
528 pub(crate) next_frame: Frame,
529 pub(crate) next_hitbox_id: HitboxId,
530 pub(crate) next_tooltip_id: TooltipId,
531 pub(crate) tooltip_bounds: Option<TooltipBounds>,
532 next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
533 pub(crate) dirty_views: FxHashSet<EntityId>,
534 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
535 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
536 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
537 default_prevented: bool,
538 mouse_position: Point<Pixels>,
539 mouse_hit_test: HitTest,
540 modifiers: Modifiers,
541 scale_factor: f32,
542 bounds_observers: SubscriberSet<(), AnyObserver>,
543 appearance: WindowAppearance,
544 appearance_observers: SubscriberSet<(), AnyObserver>,
545 active: Rc<Cell<bool>>,
546 hovered: Rc<Cell<bool>>,
547 pub(crate) dirty: Rc<Cell<bool>>,
548 pub(crate) needs_present: Rc<Cell<bool>>,
549 pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
550 pub(crate) refreshing: bool,
551 pub(crate) draw_phase: DrawPhase,
552 activation_observers: SubscriberSet<(), AnyObserver>,
553 pub(crate) focus: Option<FocusId>,
554 focus_enabled: bool,
555 pending_input: Option<PendingInput>,
556 pending_modifier: ModifierState,
557 pending_input_observers: SubscriberSet<(), AnyObserver>,
558 prompt: Option<RenderablePromptHandle>,
559}
560
561#[derive(Clone, Debug, Default)]
562struct ModifierState {
563 modifiers: Modifiers,
564 saw_keystroke: bool,
565}
566
567#[derive(Clone, Copy, Debug, Eq, PartialEq)]
568pub(crate) enum DrawPhase {
569 None,
570 Prepaint,
571 Paint,
572 Focus,
573}
574
575#[derive(Default, Debug)]
576struct PendingInput {
577 keystrokes: SmallVec<[Keystroke; 1]>,
578 focus: Option<FocusId>,
579 timer: Option<Task<()>>,
580}
581
582pub(crate) struct ElementStateBox {
583 pub(crate) inner: Box<dyn Any>,
584 #[cfg(debug_assertions)]
585 pub(crate) type_name: &'static str,
586}
587
588fn default_bounds(display_id: Option<DisplayId>, cx: &mut AppContext) -> Bounds<Pixels> {
589 const DEFAULT_WINDOW_OFFSET: Point<Pixels> = point(px(0.), px(35.));
590
591 cx.active_window()
592 .and_then(|w| w.update(cx, |_, cx| cx.bounds()).ok())
593 .map(|mut bounds| {
594 bounds.origin += DEFAULT_WINDOW_OFFSET;
595 bounds
596 })
597 .unwrap_or_else(|| {
598 let display = display_id
599 .map(|id| cx.find_display(id))
600 .unwrap_or_else(|| cx.primary_display());
601
602 display
603 .map(|display| display.default_bounds())
604 .unwrap_or_else(|| Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE))
605 })
606}
607
608impl Window {
609 pub(crate) fn new(
610 handle: AnyWindowHandle,
611 options: WindowOptions,
612 cx: &mut AppContext,
613 ) -> Result<Self> {
614 let WindowOptions {
615 window_bounds,
616 titlebar,
617 focus,
618 show,
619 kind,
620 is_movable,
621 display_id,
622 window_background,
623 app_id,
624 window_min_size,
625 window_decorations,
626 } = options;
627
628 let bounds = window_bounds
629 .map(|bounds| bounds.get_bounds())
630 .unwrap_or_else(|| default_bounds(display_id, cx));
631 let mut platform_window = cx.platform.open_window(
632 handle,
633 WindowParams {
634 bounds,
635 titlebar,
636 kind,
637 is_movable,
638 focus,
639 show,
640 display_id,
641 window_min_size,
642 },
643 )?;
644 let display_id = platform_window.display().map(|display| display.id());
645 let sprite_atlas = platform_window.sprite_atlas();
646 let mouse_position = platform_window.mouse_position();
647 let modifiers = platform_window.modifiers();
648 let content_size = platform_window.content_size();
649 let scale_factor = platform_window.scale_factor();
650 let appearance = platform_window.appearance();
651 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
652 let dirty = Rc::new(Cell::new(true));
653 let active = Rc::new(Cell::new(platform_window.is_active()));
654 let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
655 let needs_present = Rc::new(Cell::new(false));
656 let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
657 let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
658
659 platform_window
660 .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
661 platform_window.set_background_appearance(window_background);
662
663 if let Some(ref window_open_state) = window_bounds {
664 match window_open_state {
665 WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
666 WindowBounds::Maximized(_) => platform_window.zoom(),
667 WindowBounds::Windowed(_) => {}
668 }
669 }
670
671 platform_window.on_close(Box::new({
672 let mut cx = cx.to_async();
673 move || {
674 let _ = handle.update(&mut cx, |_, cx| cx.remove_window());
675 }
676 }));
677 platform_window.on_request_frame(Box::new({
678 let mut cx = cx.to_async();
679 let dirty = dirty.clone();
680 let active = active.clone();
681 let needs_present = needs_present.clone();
682 let next_frame_callbacks = next_frame_callbacks.clone();
683 let last_input_timestamp = last_input_timestamp.clone();
684 move |request_frame_options| {
685 let next_frame_callbacks = next_frame_callbacks.take();
686 if !next_frame_callbacks.is_empty() {
687 handle
688 .update(&mut cx, |_, cx| {
689 for callback in next_frame_callbacks {
690 callback(cx);
691 }
692 })
693 .log_err();
694 }
695
696 // Keep presenting the current scene for 1 extra second since the
697 // last input to prevent the display from underclocking the refresh rate.
698 let needs_present = request_frame_options.require_presentation
699 || needs_present.get()
700 || (active.get()
701 && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
702
703 if dirty.get() {
704 measure("frame duration", || {
705 handle
706 .update(&mut cx, |_, cx| {
707 cx.draw();
708 cx.present();
709 })
710 .log_err();
711 })
712 } else if needs_present {
713 handle.update(&mut cx, |_, cx| cx.present()).log_err();
714 }
715
716 handle
717 .update(&mut cx, |_, cx| {
718 cx.complete_frame();
719 })
720 .log_err();
721 }
722 }));
723 platform_window.on_resize(Box::new({
724 let mut cx = cx.to_async();
725 move |_, _| {
726 handle
727 .update(&mut cx, |_, cx| cx.bounds_changed())
728 .log_err();
729 }
730 }));
731 platform_window.on_moved(Box::new({
732 let mut cx = cx.to_async();
733 move || {
734 handle
735 .update(&mut cx, |_, cx| cx.bounds_changed())
736 .log_err();
737 }
738 }));
739 platform_window.on_appearance_changed(Box::new({
740 let mut cx = cx.to_async();
741 move || {
742 handle
743 .update(&mut cx, |_, cx| cx.appearance_changed())
744 .log_err();
745 }
746 }));
747 platform_window.on_active_status_change(Box::new({
748 let mut cx = cx.to_async();
749 move |active| {
750 handle
751 .update(&mut cx, |_, cx| {
752 cx.window.active.set(active);
753 cx.window
754 .activation_observers
755 .clone()
756 .retain(&(), |callback| callback(cx));
757 cx.refresh();
758 })
759 .log_err();
760 }
761 }));
762 platform_window.on_hover_status_change(Box::new({
763 let mut cx = cx.to_async();
764 move |active| {
765 handle
766 .update(&mut cx, |_, cx| {
767 cx.window.hovered.set(active);
768 cx.refresh();
769 })
770 .log_err();
771 }
772 }));
773 platform_window.on_input({
774 let mut cx = cx.to_async();
775 Box::new(move |event| {
776 handle
777 .update(&mut cx, |_, cx| cx.dispatch_event(event))
778 .log_err()
779 .unwrap_or(DispatchEventResult::default())
780 })
781 });
782
783 if let Some(app_id) = app_id {
784 platform_window.set_app_id(&app_id);
785 }
786
787 Ok(Window {
788 handle,
789 removed: false,
790 platform_window,
791 display_id,
792 sprite_atlas,
793 text_system,
794 rem_size: px(16.),
795 rem_size_override_stack: SmallVec::new(),
796 viewport_size: content_size,
797 layout_engine: Some(TaffyLayoutEngine::new()),
798 root_view: None,
799 element_id_stack: SmallVec::default(),
800 text_style_stack: Vec::new(),
801 element_offset_stack: Vec::new(),
802 content_mask_stack: Vec::new(),
803 element_opacity: None,
804 requested_autoscroll: None,
805 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
806 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
807 next_frame_callbacks,
808 next_hitbox_id: HitboxId::default(),
809 next_tooltip_id: TooltipId::default(),
810 tooltip_bounds: None,
811 dirty_views: FxHashSet::default(),
812 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
813 focus_listeners: SubscriberSet::new(),
814 focus_lost_listeners: SubscriberSet::new(),
815 default_prevented: true,
816 mouse_position,
817 mouse_hit_test: HitTest::default(),
818 modifiers,
819 scale_factor,
820 bounds_observers: SubscriberSet::new(),
821 appearance,
822 appearance_observers: SubscriberSet::new(),
823 active,
824 hovered,
825 dirty,
826 needs_present,
827 last_input_timestamp,
828 refreshing: false,
829 draw_phase: DrawPhase::None,
830 activation_observers: SubscriberSet::new(),
831 focus: None,
832 focus_enabled: true,
833 pending_input: None,
834 pending_modifier: ModifierState::default(),
835 pending_input_observers: SubscriberSet::new(),
836 prompt: None,
837 })
838 }
839 fn new_focus_listener(&self, value: AnyWindowFocusListener) -> (Subscription, impl FnOnce()) {
840 self.focus_listeners.insert((), value)
841 }
842}
843
844#[derive(Clone, Debug, Default, PartialEq, Eq)]
845pub(crate) struct DispatchEventResult {
846 pub propagate: bool,
847 pub default_prevented: bool,
848}
849
850/// Indicates which region of the window is visible. Content falling outside of this mask will not be
851/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
852/// to leave room to support more complex shapes in the future.
853#[derive(Clone, Debug, Default, PartialEq, Eq)]
854#[repr(C)]
855pub struct ContentMask<P: Clone + Default + Debug> {
856 /// The bounds
857 pub bounds: Bounds<P>,
858}
859
860impl ContentMask<Pixels> {
861 /// Scale the content mask's pixel units by the given scaling factor.
862 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
863 ContentMask {
864 bounds: self.bounds.scale(factor),
865 }
866 }
867
868 /// Intersect the content mask with the given content mask.
869 pub fn intersect(&self, other: &Self) -> Self {
870 let bounds = self.bounds.intersect(&other.bounds);
871 ContentMask { bounds }
872 }
873}
874
875/// Provides access to application state in the context of a single window. Derefs
876/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
877/// an [`AppContext`] and call any [`AppContext`] methods.
878pub struct WindowContext<'a> {
879 pub(crate) app: &'a mut AppContext,
880 pub(crate) window: &'a mut Window,
881}
882
883impl<'a> WindowContext<'a> {
884 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
885 Self { app, window }
886 }
887
888 /// Obtain a handle to the window that belongs to this context.
889 pub fn window_handle(&self) -> AnyWindowHandle {
890 self.window.handle
891 }
892
893 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
894 pub fn refresh(&mut self) {
895 if self.window.draw_phase == DrawPhase::None {
896 self.window.refreshing = true;
897 self.window.dirty.set(true);
898 }
899 }
900
901 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
902 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
903 /// Note that this method will always cause a redraw, the entire window is refreshed if view_id is None.
904 pub fn notify(&mut self, view_id: Option<EntityId>) {
905 let Some(view_id) = view_id else {
906 self.refresh();
907 return;
908 };
909
910 for view_id in self
911 .window
912 .rendered_frame
913 .dispatch_tree
914 .view_path(view_id)
915 .into_iter()
916 .rev()
917 {
918 if !self.window.dirty_views.insert(view_id) {
919 break;
920 }
921 }
922
923 if self.window.draw_phase == DrawPhase::None {
924 self.window.dirty.set(true);
925 self.app.push_effect(Effect::Notify { emitter: view_id });
926 }
927 }
928
929 /// Close this window.
930 pub fn remove_window(&mut self) {
931 self.window.removed = true;
932 }
933
934 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
935 /// for elements rendered within this window.
936 pub fn focus_handle(&self) -> FocusHandle {
937 FocusHandle::new(&self.window.focus_handles)
938 }
939
940 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
941 pub fn focused(&self) -> Option<FocusHandle> {
942 self.window
943 .focus
944 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
945 }
946
947 /// Move focus to the element associated with the given [`FocusHandle`].
948 pub fn focus(&mut self, handle: &FocusHandle) {
949 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
950 return;
951 }
952
953 self.window.focus = Some(handle.id);
954 self.clear_pending_keystrokes();
955 self.refresh();
956 }
957
958 /// Remove focus from all elements within this context's window.
959 pub fn blur(&mut self) {
960 if !self.window.focus_enabled {
961 return;
962 }
963
964 self.window.focus = None;
965 self.refresh();
966 }
967
968 /// Blur the window and don't allow anything in it to be focused again.
969 pub fn disable_focus(&mut self) {
970 self.blur();
971 self.window.focus_enabled = false;
972 }
973
974 /// Accessor for the text system.
975 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
976 &self.window.text_system
977 }
978
979 /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
980 pub fn text_style(&self) -> TextStyle {
981 let mut style = TextStyle::default();
982 for refinement in &self.window.text_style_stack {
983 style.refine(refinement);
984 }
985 style
986 }
987
988 /// Check if the platform window is maximized
989 /// On some platforms (namely Windows) this is different than the bounds being the size of the display
990 pub fn is_maximized(&self) -> bool {
991 self.window.platform_window.is_maximized()
992 }
993
994 /// request a certain window decoration (Wayland)
995 pub fn request_decorations(&self, decorations: WindowDecorations) {
996 self.window.platform_window.request_decorations(decorations);
997 }
998
999 /// Start a window resize operation (Wayland)
1000 pub fn start_window_resize(&self, edge: ResizeEdge) {
1001 self.window.platform_window.start_window_resize(edge);
1002 }
1003
1004 /// Return the `WindowBounds` to indicate that how a window should be opened
1005 /// after it has been closed
1006 pub fn window_bounds(&self) -> WindowBounds {
1007 self.window.platform_window.window_bounds()
1008 }
1009
1010 /// Dispatch the given action on the currently focused element.
1011 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
1012 let focus_handle = self.focused();
1013
1014 let window = self.window.handle;
1015 self.app.defer(move |cx| {
1016 window
1017 .update(cx, |_, cx| {
1018 let node_id = focus_handle
1019 .and_then(|handle| {
1020 cx.window
1021 .rendered_frame
1022 .dispatch_tree
1023 .focusable_node_id(handle.id)
1024 })
1025 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
1026
1027 cx.dispatch_action_on_node(node_id, action.as_ref());
1028 })
1029 .log_err();
1030 })
1031 }
1032
1033 pub(crate) fn dispatch_keystroke_observers(
1034 &mut self,
1035 event: &dyn Any,
1036 action: Option<Box<dyn Action>>,
1037 ) {
1038 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1039 return;
1040 };
1041
1042 self.keystroke_observers
1043 .clone()
1044 .retain(&(), move |callback| {
1045 (callback)(
1046 &KeystrokeEvent {
1047 keystroke: key_down_event.keystroke.clone(),
1048 action: action.as_ref().map(|action| action.boxed_clone()),
1049 },
1050 self,
1051 )
1052 });
1053 }
1054
1055 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1056 /// that are currently on the stack to be returned to the app.
1057 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
1058 let handle = self.window.handle;
1059 self.app.defer(move |cx| {
1060 handle.update(cx, |_, cx| f(cx)).ok();
1061 });
1062 }
1063
1064 /// Subscribe to events emitted by a model or view.
1065 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1066 /// 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.
1067 pub fn observe<E, T>(
1068 &mut self,
1069 entity: &E,
1070 mut on_notify: impl FnMut(E, &mut WindowContext<'_>) + 'static,
1071 ) -> Subscription
1072 where
1073 E: Entity<T>,
1074 {
1075 let entity_id = entity.entity_id();
1076 let entity = entity.downgrade();
1077 let window_handle = self.window.handle;
1078 self.app.new_observer(
1079 entity_id,
1080 Box::new(move |cx| {
1081 window_handle
1082 .update(cx, |_, cx| {
1083 if let Some(handle) = E::upgrade_from(&entity) {
1084 on_notify(handle, cx);
1085 true
1086 } else {
1087 false
1088 }
1089 })
1090 .unwrap_or(false)
1091 }),
1092 )
1093 }
1094
1095 /// Subscribe to events emitted by a model or view.
1096 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1097 /// 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.
1098 pub fn subscribe<Emitter, E, Evt>(
1099 &mut self,
1100 entity: &E,
1101 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
1102 ) -> Subscription
1103 where
1104 Emitter: EventEmitter<Evt>,
1105 E: Entity<Emitter>,
1106 Evt: 'static,
1107 {
1108 let entity_id = entity.entity_id();
1109 let entity = entity.downgrade();
1110 let window_handle = self.window.handle;
1111 self.app.new_subscription(
1112 entity_id,
1113 (
1114 TypeId::of::<Evt>(),
1115 Box::new(move |event, cx| {
1116 window_handle
1117 .update(cx, |_, cx| {
1118 if let Some(handle) = E::upgrade_from(&entity) {
1119 let event = event.downcast_ref().expect("invalid event type");
1120 on_event(handle, event, cx);
1121 true
1122 } else {
1123 false
1124 }
1125 })
1126 .unwrap_or(false)
1127 }),
1128 ),
1129 )
1130 }
1131
1132 /// Register a callback to be invoked when the given Model or View is released.
1133 pub fn observe_release<E, T>(
1134 &self,
1135 entity: &E,
1136 mut on_release: impl FnOnce(&mut T, &mut WindowContext) + 'static,
1137 ) -> Subscription
1138 where
1139 E: Entity<T>,
1140 T: 'static,
1141 {
1142 let entity_id = entity.entity_id();
1143 let window_handle = self.window.handle;
1144 let (subscription, activate) = self.app.release_listeners.insert(
1145 entity_id,
1146 Box::new(move |entity, cx| {
1147 let entity = entity.downcast_mut().expect("invalid entity type");
1148 let _ = window_handle.update(cx, |_, cx| on_release(entity, cx));
1149 }),
1150 );
1151 activate();
1152 subscription
1153 }
1154
1155 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1156 /// await points in async code.
1157 pub fn to_async(&self) -> AsyncWindowContext {
1158 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
1159 }
1160
1161 /// Schedule the given closure to be run directly after the current frame is rendered.
1162 pub fn on_next_frame(&self, callback: impl FnOnce(&mut WindowContext) + 'static) {
1163 RefCell::borrow_mut(&self.window.next_frame_callbacks).push(Box::new(callback));
1164 }
1165
1166 /// Schedule a frame to be drawn on the next animation frame.
1167 ///
1168 /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1169 /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1170 ///
1171 /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1172 pub fn request_animation_frame(&self) {
1173 let parent_id = self.parent_view_id();
1174 self.on_next_frame(move |cx| cx.notify(parent_id));
1175 }
1176
1177 /// Spawn the future returned by the given closure on the application thread pool.
1178 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1179 /// use within your future.
1180 pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
1181 where
1182 R: 'static,
1183 Fut: Future<Output = R> + 'static,
1184 {
1185 self.app
1186 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
1187 }
1188
1189 fn bounds_changed(&mut self) {
1190 self.window.scale_factor = self.window.platform_window.scale_factor();
1191 self.window.viewport_size = self.window.platform_window.content_size();
1192 self.window.display_id = self
1193 .window
1194 .platform_window
1195 .display()
1196 .map(|display| display.id());
1197
1198 self.refresh();
1199
1200 self.window
1201 .bounds_observers
1202 .clone()
1203 .retain(&(), |callback| callback(self));
1204 }
1205
1206 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1207 pub fn bounds(&self) -> Bounds<Pixels> {
1208 self.window.platform_window.bounds()
1209 }
1210
1211 /// Returns whether or not the window is currently fullscreen
1212 pub fn is_fullscreen(&self) -> bool {
1213 self.window.platform_window.is_fullscreen()
1214 }
1215
1216 pub(crate) fn appearance_changed(&mut self) {
1217 self.window.appearance = self.window.platform_window.appearance();
1218
1219 self.window
1220 .appearance_observers
1221 .clone()
1222 .retain(&(), |callback| callback(self));
1223 }
1224
1225 /// Returns the appearance of the current window.
1226 pub fn appearance(&self) -> WindowAppearance {
1227 self.window.appearance
1228 }
1229
1230 /// Returns the size of the drawable area within the window.
1231 pub fn viewport_size(&self) -> Size<Pixels> {
1232 self.window.viewport_size
1233 }
1234
1235 /// Returns whether this window is focused by the operating system (receiving key events).
1236 pub fn is_window_active(&self) -> bool {
1237 self.window.active.get()
1238 }
1239
1240 /// Returns whether this window is considered to be the window
1241 /// that currently owns the mouse cursor.
1242 /// On mac, this is equivalent to `is_window_active`.
1243 pub fn is_window_hovered(&self) -> bool {
1244 if cfg!(any(
1245 target_os = "windows",
1246 target_os = "linux",
1247 target_os = "freebsd"
1248 )) {
1249 self.window.hovered.get()
1250 } else {
1251 self.is_window_active()
1252 }
1253 }
1254
1255 /// Toggle zoom on the window.
1256 pub fn zoom_window(&self) {
1257 self.window.platform_window.zoom();
1258 }
1259
1260 /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1261 pub fn show_window_menu(&self, position: Point<Pixels>) {
1262 self.window.platform_window.show_window_menu(position)
1263 }
1264
1265 /// Tells the compositor to take control of window movement (Wayland and X11)
1266 ///
1267 /// Events may not be received during a move operation.
1268 pub fn start_window_move(&self) {
1269 self.window.platform_window.start_window_move()
1270 }
1271
1272 /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
1273 pub fn set_client_inset(&self, inset: Pixels) {
1274 self.window.platform_window.set_client_inset(inset);
1275 }
1276
1277 /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1278 pub fn window_decorations(&self) -> Decorations {
1279 self.window.platform_window.window_decorations()
1280 }
1281
1282 /// Returns which window controls are currently visible (Wayland)
1283 pub fn window_controls(&self) -> WindowControls {
1284 self.window.platform_window.window_controls()
1285 }
1286
1287 /// Updates the window's title at the platform level.
1288 pub fn set_window_title(&mut self, title: &str) {
1289 self.window.platform_window.set_title(title);
1290 }
1291
1292 /// Sets the application identifier.
1293 pub fn set_app_id(&mut self, app_id: &str) {
1294 self.window.platform_window.set_app_id(app_id);
1295 }
1296
1297 /// Sets the window background appearance.
1298 pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
1299 self.window
1300 .platform_window
1301 .set_background_appearance(background_appearance);
1302 }
1303
1304 /// Mark the window as dirty at the platform level.
1305 pub fn set_window_edited(&mut self, edited: bool) {
1306 self.window.platform_window.set_edited(edited);
1307 }
1308
1309 /// Determine the display on which the window is visible.
1310 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
1311 self.platform
1312 .displays()
1313 .into_iter()
1314 .find(|display| Some(display.id()) == self.window.display_id)
1315 }
1316
1317 /// Show the platform character palette.
1318 pub fn show_character_palette(&self) {
1319 self.window.platform_window.show_character_palette();
1320 }
1321
1322 /// The scale factor of the display associated with the window. For example, it could
1323 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
1324 /// be rendered as two pixels on screen.
1325 pub fn scale_factor(&self) -> f32 {
1326 self.window.scale_factor
1327 }
1328
1329 /// The size of an em for the base font of the application. Adjusting this value allows the
1330 /// UI to scale, just like zooming a web page.
1331 pub fn rem_size(&self) -> Pixels {
1332 self.window
1333 .rem_size_override_stack
1334 .last()
1335 .copied()
1336 .unwrap_or(self.window.rem_size)
1337 }
1338
1339 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
1340 /// UI to scale, just like zooming a web page.
1341 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
1342 self.window.rem_size = rem_size.into();
1343 }
1344
1345 /// Executes the provided function with the specified rem size.
1346 ///
1347 /// This method must only be called as part of element drawing.
1348 pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
1349 where
1350 F: FnOnce(&mut Self) -> R,
1351 {
1352 debug_assert!(
1353 matches!(
1354 self.window.draw_phase,
1355 DrawPhase::Prepaint | DrawPhase::Paint
1356 ),
1357 "this method can only be called during request_layout, prepaint, or paint"
1358 );
1359
1360 if let Some(rem_size) = rem_size {
1361 self.window.rem_size_override_stack.push(rem_size.into());
1362 let result = f(self);
1363 self.window.rem_size_override_stack.pop();
1364 result
1365 } else {
1366 f(self)
1367 }
1368 }
1369
1370 /// The line height associated with the current text style.
1371 pub fn line_height(&self) -> Pixels {
1372 self.text_style().line_height_in_pixels(self.rem_size())
1373 }
1374
1375 /// Call to prevent the default action of an event. Currently only used to prevent
1376 /// parent elements from becoming focused on mouse down.
1377 pub fn prevent_default(&mut self) {
1378 self.window.default_prevented = true;
1379 }
1380
1381 /// Obtain whether default has been prevented for the event currently being dispatched.
1382 pub fn default_prevented(&self) -> bool {
1383 self.window.default_prevented
1384 }
1385
1386 /// Determine whether the given action is available along the dispatch path to the currently focused element.
1387 pub fn is_action_available(&self, action: &dyn Action) -> bool {
1388 let target = self
1389 .focused()
1390 .and_then(|focused_handle| {
1391 self.window
1392 .rendered_frame
1393 .dispatch_tree
1394 .focusable_node_id(focused_handle.id)
1395 })
1396 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1397 self.window
1398 .rendered_frame
1399 .dispatch_tree
1400 .is_action_available(action, target)
1401 }
1402
1403 /// The position of the mouse relative to the window.
1404 pub fn mouse_position(&self) -> Point<Pixels> {
1405 self.window.mouse_position
1406 }
1407
1408 /// The current state of the keyboard's modifiers
1409 pub fn modifiers(&self) -> Modifiers {
1410 self.window.modifiers
1411 }
1412
1413 fn complete_frame(&self) {
1414 self.window.platform_window.completed_frame();
1415 }
1416
1417 /// Produces a new frame and assigns it to `rendered_frame`. To actually show
1418 /// the contents of the new [Scene], use [present].
1419 #[profiling::function]
1420 pub fn draw(&mut self) {
1421 self.window.dirty.set(false);
1422 self.window.requested_autoscroll = None;
1423
1424 // Restore the previously-used input handler.
1425 if let Some(input_handler) = self.window.platform_window.take_input_handler() {
1426 self.window
1427 .rendered_frame
1428 .input_handlers
1429 .push(Some(input_handler));
1430 }
1431
1432 self.draw_roots();
1433 self.window.dirty_views.clear();
1434 self.window.next_frame.window_active = self.window.active.get();
1435
1436 // Register requested input handler with the platform window.
1437 if let Some(input_handler) = self.window.next_frame.input_handlers.pop() {
1438 self.window
1439 .platform_window
1440 .set_input_handler(input_handler.unwrap());
1441 }
1442
1443 self.window.layout_engine.as_mut().unwrap().clear();
1444 self.text_system().finish_frame();
1445 self.window
1446 .next_frame
1447 .finish(&mut self.window.rendered_frame);
1448 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1449 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1450 if percentage >= 80. {
1451 log::warn!("elevated element arena occupation: {}.", percentage);
1452 }
1453 element_arena.clear();
1454 });
1455
1456 self.window.draw_phase = DrawPhase::Focus;
1457 let previous_focus_path = self.window.rendered_frame.focus_path();
1458 let previous_window_active = self.window.rendered_frame.window_active;
1459 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1460 self.window.next_frame.clear();
1461 let current_focus_path = self.window.rendered_frame.focus_path();
1462 let current_window_active = self.window.rendered_frame.window_active;
1463
1464 if previous_focus_path != current_focus_path
1465 || previous_window_active != current_window_active
1466 {
1467 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1468 self.window
1469 .focus_lost_listeners
1470 .clone()
1471 .retain(&(), |listener| listener(self));
1472 }
1473
1474 let event = WindowFocusEvent {
1475 previous_focus_path: if previous_window_active {
1476 previous_focus_path
1477 } else {
1478 Default::default()
1479 },
1480 current_focus_path: if current_window_active {
1481 current_focus_path
1482 } else {
1483 Default::default()
1484 },
1485 };
1486 self.window
1487 .focus_listeners
1488 .clone()
1489 .retain(&(), |listener| listener(&event, self));
1490 }
1491
1492 self.reset_cursor_style();
1493 self.window.refreshing = false;
1494 self.window.draw_phase = DrawPhase::None;
1495 self.window.needs_present.set(true);
1496 }
1497
1498 #[profiling::function]
1499 fn present(&self) {
1500 self.window
1501 .platform_window
1502 .draw(&self.window.rendered_frame.scene);
1503 self.window.needs_present.set(false);
1504 profiling::finish_frame!();
1505 }
1506
1507 fn draw_roots(&mut self) {
1508 self.window.draw_phase = DrawPhase::Prepaint;
1509 self.window.tooltip_bounds.take();
1510
1511 // Layout all root elements.
1512 let mut root_element = self.window.root_view.as_ref().unwrap().clone().into_any();
1513 root_element.prepaint_as_root(Point::default(), self.window.viewport_size.into(), self);
1514
1515 let mut sorted_deferred_draws =
1516 (0..self.window.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
1517 sorted_deferred_draws.sort_by_key(|ix| self.window.next_frame.deferred_draws[*ix].priority);
1518 self.prepaint_deferred_draws(&sorted_deferred_draws);
1519
1520 let mut prompt_element = None;
1521 let mut active_drag_element = None;
1522 let mut tooltip_element = None;
1523 if let Some(prompt) = self.window.prompt.take() {
1524 let mut element = prompt.view.any_view().into_any();
1525 element.prepaint_as_root(Point::default(), self.window.viewport_size.into(), self);
1526 prompt_element = Some(element);
1527 self.window.prompt = Some(prompt);
1528 } else if let Some(active_drag) = self.app.active_drag.take() {
1529 let mut element = active_drag.view.clone().into_any();
1530 let offset = self.mouse_position() - active_drag.cursor_offset;
1531 element.prepaint_as_root(offset, AvailableSpace::min_size(), self);
1532 active_drag_element = Some(element);
1533 self.app.active_drag = Some(active_drag);
1534 } else {
1535 tooltip_element = self.prepaint_tooltip();
1536 }
1537
1538 self.window.mouse_hit_test = self.window.next_frame.hit_test(self.window.mouse_position);
1539
1540 // Now actually paint the elements.
1541 self.window.draw_phase = DrawPhase::Paint;
1542 root_element.paint(self);
1543
1544 self.paint_deferred_draws(&sorted_deferred_draws);
1545
1546 if let Some(mut prompt_element) = prompt_element {
1547 prompt_element.paint(self);
1548 } else if let Some(mut drag_element) = active_drag_element {
1549 drag_element.paint(self);
1550 } else if let Some(mut tooltip_element) = tooltip_element {
1551 tooltip_element.paint(self);
1552 }
1553 }
1554
1555 fn prepaint_tooltip(&mut self) -> Option<AnyElement> {
1556 let tooltip_request = self.window.next_frame.tooltip_requests.last().cloned()?;
1557 let tooltip_request = tooltip_request.unwrap();
1558 let mut element = tooltip_request.tooltip.view.clone().into_any();
1559 let mouse_position = tooltip_request.tooltip.mouse_position;
1560 let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self);
1561
1562 let mut tooltip_bounds = Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
1563 let window_bounds = Bounds {
1564 origin: Point::default(),
1565 size: self.viewport_size(),
1566 };
1567
1568 if tooltip_bounds.right() > window_bounds.right() {
1569 let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
1570 if new_x >= Pixels::ZERO {
1571 tooltip_bounds.origin.x = new_x;
1572 } else {
1573 tooltip_bounds.origin.x = cmp::max(
1574 Pixels::ZERO,
1575 tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
1576 );
1577 }
1578 }
1579
1580 if tooltip_bounds.bottom() > window_bounds.bottom() {
1581 let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
1582 if new_y >= Pixels::ZERO {
1583 tooltip_bounds.origin.y = new_y;
1584 } else {
1585 tooltip_bounds.origin.y = cmp::max(
1586 Pixels::ZERO,
1587 tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
1588 );
1589 }
1590 }
1591
1592 self.with_absolute_element_offset(tooltip_bounds.origin, |cx| element.prepaint(cx));
1593
1594 self.window.tooltip_bounds = Some(TooltipBounds {
1595 id: tooltip_request.id,
1596 bounds: tooltip_bounds,
1597 });
1598 Some(element)
1599 }
1600
1601 fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize]) {
1602 assert_eq!(self.window.element_id_stack.len(), 0);
1603
1604 let mut deferred_draws = mem::take(&mut self.window.next_frame.deferred_draws);
1605 for deferred_draw_ix in deferred_draw_indices {
1606 let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1607 self.window
1608 .element_id_stack
1609 .clone_from(&deferred_draw.element_id_stack);
1610 self.window
1611 .text_style_stack
1612 .clone_from(&deferred_draw.text_style_stack);
1613 self.window
1614 .next_frame
1615 .dispatch_tree
1616 .set_active_node(deferred_draw.parent_node);
1617
1618 let prepaint_start = self.prepaint_index();
1619 if let Some(element) = deferred_draw.element.as_mut() {
1620 self.with_absolute_element_offset(deferred_draw.absolute_offset, |cx| {
1621 element.prepaint(cx)
1622 });
1623 } else {
1624 self.reuse_prepaint(deferred_draw.prepaint_range.clone());
1625 }
1626 let prepaint_end = self.prepaint_index();
1627 deferred_draw.prepaint_range = prepaint_start..prepaint_end;
1628 }
1629 assert_eq!(
1630 self.window.next_frame.deferred_draws.len(),
1631 0,
1632 "cannot call defer_draw during deferred drawing"
1633 );
1634 self.window.next_frame.deferred_draws = deferred_draws;
1635 self.window.element_id_stack.clear();
1636 self.window.text_style_stack.clear();
1637 }
1638
1639 fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize]) {
1640 assert_eq!(self.window.element_id_stack.len(), 0);
1641
1642 let mut deferred_draws = mem::take(&mut self.window.next_frame.deferred_draws);
1643 for deferred_draw_ix in deferred_draw_indices {
1644 let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1645 self.window
1646 .element_id_stack
1647 .clone_from(&deferred_draw.element_id_stack);
1648 self.window
1649 .next_frame
1650 .dispatch_tree
1651 .set_active_node(deferred_draw.parent_node);
1652
1653 let paint_start = self.paint_index();
1654 if let Some(element) = deferred_draw.element.as_mut() {
1655 element.paint(self);
1656 } else {
1657 self.reuse_paint(deferred_draw.paint_range.clone());
1658 }
1659 let paint_end = self.paint_index();
1660 deferred_draw.paint_range = paint_start..paint_end;
1661 }
1662 self.window.next_frame.deferred_draws = deferred_draws;
1663 self.window.element_id_stack.clear();
1664 }
1665
1666 pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
1667 PrepaintStateIndex {
1668 hitboxes_index: self.window.next_frame.hitboxes.len(),
1669 tooltips_index: self.window.next_frame.tooltip_requests.len(),
1670 deferred_draws_index: self.window.next_frame.deferred_draws.len(),
1671 dispatch_tree_index: self.window.next_frame.dispatch_tree.len(),
1672 accessed_element_states_index: self.window.next_frame.accessed_element_states.len(),
1673 line_layout_index: self.window.text_system.layout_index(),
1674 }
1675 }
1676
1677 pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
1678 let window = &mut self.window;
1679 window.next_frame.hitboxes.extend(
1680 window.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
1681 .iter()
1682 .cloned(),
1683 );
1684 window.next_frame.tooltip_requests.extend(
1685 window.rendered_frame.tooltip_requests
1686 [range.start.tooltips_index..range.end.tooltips_index]
1687 .iter_mut()
1688 .map(|request| request.take()),
1689 );
1690 window.next_frame.accessed_element_states.extend(
1691 window.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
1692 ..range.end.accessed_element_states_index]
1693 .iter()
1694 .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
1695 );
1696 window
1697 .text_system
1698 .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
1699
1700 let reused_subtree = window.next_frame.dispatch_tree.reuse_subtree(
1701 range.start.dispatch_tree_index..range.end.dispatch_tree_index,
1702 &mut window.rendered_frame.dispatch_tree,
1703 window.focus,
1704 );
1705
1706 if reused_subtree.contains_focus() {
1707 window.next_frame.focus = window.focus;
1708 }
1709
1710 window.next_frame.deferred_draws.extend(
1711 window.rendered_frame.deferred_draws
1712 [range.start.deferred_draws_index..range.end.deferred_draws_index]
1713 .iter()
1714 .map(|deferred_draw| DeferredDraw {
1715 parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
1716 element_id_stack: deferred_draw.element_id_stack.clone(),
1717 text_style_stack: deferred_draw.text_style_stack.clone(),
1718 priority: deferred_draw.priority,
1719 element: None,
1720 absolute_offset: deferred_draw.absolute_offset,
1721 prepaint_range: deferred_draw.prepaint_range.clone(),
1722 paint_range: deferred_draw.paint_range.clone(),
1723 }),
1724 );
1725 }
1726
1727 pub(crate) fn paint_index(&self) -> PaintIndex {
1728 PaintIndex {
1729 scene_index: self.window.next_frame.scene.len(),
1730 mouse_listeners_index: self.window.next_frame.mouse_listeners.len(),
1731 input_handlers_index: self.window.next_frame.input_handlers.len(),
1732 cursor_styles_index: self.window.next_frame.cursor_styles.len(),
1733 accessed_element_states_index: self.window.next_frame.accessed_element_states.len(),
1734 line_layout_index: self.window.text_system.layout_index(),
1735 }
1736 }
1737
1738 pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
1739 let window = &mut self.window;
1740
1741 window.next_frame.cursor_styles.extend(
1742 window.rendered_frame.cursor_styles
1743 [range.start.cursor_styles_index..range.end.cursor_styles_index]
1744 .iter()
1745 .cloned(),
1746 );
1747 window.next_frame.input_handlers.extend(
1748 window.rendered_frame.input_handlers
1749 [range.start.input_handlers_index..range.end.input_handlers_index]
1750 .iter_mut()
1751 .map(|handler| handler.take()),
1752 );
1753 window.next_frame.mouse_listeners.extend(
1754 window.rendered_frame.mouse_listeners
1755 [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
1756 .iter_mut()
1757 .map(|listener| listener.take()),
1758 );
1759 if let Some(element_states) = window
1760 .rendered_frame
1761 .accessed_element_states
1762 .get(range.start.accessed_element_states_index..range.end.accessed_element_states_index)
1763 {
1764 window.next_frame.accessed_element_states.extend(
1765 element_states
1766 .iter()
1767 .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
1768 );
1769 }
1770
1771 window
1772 .text_system
1773 .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
1774 window.next_frame.scene.replay(
1775 range.start.scene_index..range.end.scene_index,
1776 &window.rendered_frame.scene,
1777 );
1778 }
1779
1780 /// Push a text style onto the stack, and call a function with that style active.
1781 /// Use [`AppContext::text_style`] to get the current, combined text style. This method
1782 /// should only be called as part of element drawing.
1783 pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
1784 where
1785 F: FnOnce(&mut Self) -> R,
1786 {
1787 debug_assert!(
1788 matches!(
1789 self.window.draw_phase,
1790 DrawPhase::Prepaint | DrawPhase::Paint
1791 ),
1792 "this method can only be called during request_layout, prepaint, or paint"
1793 );
1794 if let Some(style) = style {
1795 self.window.text_style_stack.push(style);
1796 let result = f(self);
1797 self.window.text_style_stack.pop();
1798 result
1799 } else {
1800 f(self)
1801 }
1802 }
1803
1804 /// Updates the cursor style at the platform level. This method should only be called
1805 /// during the prepaint phase of element drawing.
1806 pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
1807 debug_assert_eq!(
1808 self.window.draw_phase,
1809 DrawPhase::Paint,
1810 "this method can only be called during paint"
1811 );
1812 self.window
1813 .next_frame
1814 .cursor_styles
1815 .push(CursorStyleRequest {
1816 hitbox_id: hitbox.id,
1817 style,
1818 });
1819 }
1820
1821 /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
1822 /// during the paint phase of element drawing.
1823 pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
1824 debug_assert_eq!(
1825 self.window.draw_phase,
1826 DrawPhase::Prepaint,
1827 "this method can only be called during prepaint"
1828 );
1829 let id = TooltipId(post_inc(&mut self.window.next_tooltip_id.0));
1830 self.window
1831 .next_frame
1832 .tooltip_requests
1833 .push(Some(TooltipRequest { id, tooltip }));
1834 id
1835 }
1836
1837 /// Invoke the given function with the given content mask after intersecting it
1838 /// with the current mask. This method should only be called during element drawing.
1839 pub fn with_content_mask<R>(
1840 &mut self,
1841 mask: Option<ContentMask<Pixels>>,
1842 f: impl FnOnce(&mut Self) -> R,
1843 ) -> R {
1844 debug_assert!(
1845 matches!(
1846 self.window.draw_phase,
1847 DrawPhase::Prepaint | DrawPhase::Paint
1848 ),
1849 "this method can only be called during request_layout, prepaint, or paint"
1850 );
1851 if let Some(mask) = mask {
1852 let mask = mask.intersect(&self.content_mask());
1853 self.window_mut().content_mask_stack.push(mask);
1854 let result = f(self);
1855 self.window_mut().content_mask_stack.pop();
1856 result
1857 } else {
1858 f(self)
1859 }
1860 }
1861
1862 /// Updates the global element offset relative to the current offset. This is used to implement
1863 /// scrolling. This method should only be called during the prepaint phase of element drawing.
1864 pub fn with_element_offset<R>(
1865 &mut self,
1866 offset: Point<Pixels>,
1867 f: impl FnOnce(&mut Self) -> R,
1868 ) -> R {
1869 debug_assert_eq!(
1870 self.window.draw_phase,
1871 DrawPhase::Prepaint,
1872 "this method can only be called during request_layout, or prepaint"
1873 );
1874
1875 if offset.is_zero() {
1876 return f(self);
1877 };
1878
1879 let abs_offset = self.element_offset() + offset;
1880 self.with_absolute_element_offset(abs_offset, f)
1881 }
1882
1883 /// Updates the global element offset based on the given offset. This is used to implement
1884 /// drag handles and other manual painting of elements. This method should only be called during
1885 /// the prepaint phase of element drawing.
1886 pub fn with_absolute_element_offset<R>(
1887 &mut self,
1888 offset: Point<Pixels>,
1889 f: impl FnOnce(&mut Self) -> R,
1890 ) -> R {
1891 debug_assert_eq!(
1892 self.window.draw_phase,
1893 DrawPhase::Prepaint,
1894 "this method can only be called during request_layout, or prepaint"
1895 );
1896 self.window_mut().element_offset_stack.push(offset);
1897 let result = f(self);
1898 self.window_mut().element_offset_stack.pop();
1899 result
1900 }
1901
1902 pub(crate) fn with_element_opacity<R>(
1903 &mut self,
1904 opacity: Option<f32>,
1905 f: impl FnOnce(&mut Self) -> R,
1906 ) -> R {
1907 if opacity.is_none() {
1908 return f(self);
1909 }
1910
1911 debug_assert!(
1912 matches!(
1913 self.window.draw_phase,
1914 DrawPhase::Prepaint | DrawPhase::Paint
1915 ),
1916 "this method can only be called during prepaint, or paint"
1917 );
1918 self.window_mut().element_opacity = opacity;
1919 let result = f(self);
1920 self.window_mut().element_opacity = None;
1921 result
1922 }
1923
1924 /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
1925 /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
1926 /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
1927 /// element offset and prepaint again. See [`List`] for an example. This method should only be
1928 /// called during the prepaint phase of element drawing.
1929 pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
1930 debug_assert_eq!(
1931 self.window.draw_phase,
1932 DrawPhase::Prepaint,
1933 "this method can only be called during prepaint"
1934 );
1935 let index = self.prepaint_index();
1936 let result = f(self);
1937 if result.is_err() {
1938 self.window
1939 .next_frame
1940 .hitboxes
1941 .truncate(index.hitboxes_index);
1942 self.window
1943 .next_frame
1944 .tooltip_requests
1945 .truncate(index.tooltips_index);
1946 self.window
1947 .next_frame
1948 .deferred_draws
1949 .truncate(index.deferred_draws_index);
1950 self.window
1951 .next_frame
1952 .dispatch_tree
1953 .truncate(index.dispatch_tree_index);
1954 self.window
1955 .next_frame
1956 .accessed_element_states
1957 .truncate(index.accessed_element_states_index);
1958 self.window
1959 .text_system
1960 .truncate_layouts(index.line_layout_index);
1961 }
1962 result
1963 }
1964
1965 /// When you call this method during [`prepaint`], containing elements will attempt to
1966 /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
1967 /// [`prepaint`] again with a new set of bounds. See [`List`] for an example of an element
1968 /// that supports this method being called on the elements it contains. This method should only be
1969 /// called during the prepaint phase of element drawing.
1970 pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
1971 debug_assert_eq!(
1972 self.window.draw_phase,
1973 DrawPhase::Prepaint,
1974 "this method can only be called during prepaint"
1975 );
1976 self.window.requested_autoscroll = Some(bounds);
1977 }
1978
1979 /// This method can be called from a containing element such as [`List`] to support the autoscroll behavior
1980 /// described in [`request_autoscroll`].
1981 pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
1982 debug_assert_eq!(
1983 self.window.draw_phase,
1984 DrawPhase::Prepaint,
1985 "this method can only be called during prepaint"
1986 );
1987 self.window.requested_autoscroll.take()
1988 }
1989
1990 /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
1991 /// Your view will be re-drawn once the asset has finished loading.
1992 ///
1993 /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
1994 /// time.
1995 pub fn use_asset<A: Asset>(&mut self, source: &A::Source) -> Option<A::Output> {
1996 let (task, is_first) = self.fetch_asset::<A>(source);
1997 task.clone().now_or_never().or_else(|| {
1998 if is_first {
1999 let parent_id = self.parent_view_id();
2000 self.spawn({
2001 let task = task.clone();
2002 |mut cx| async move {
2003 task.await;
2004
2005 cx.on_next_frame(move |cx| cx.notify(parent_id));
2006 }
2007 })
2008 .detach();
2009 }
2010
2011 None
2012 })
2013 }
2014 /// Obtain the current element offset. This method should only be called during the
2015 /// prepaint phase of element drawing.
2016 pub fn element_offset(&self) -> Point<Pixels> {
2017 debug_assert_eq!(
2018 self.window.draw_phase,
2019 DrawPhase::Prepaint,
2020 "this method can only be called during prepaint"
2021 );
2022 self.window()
2023 .element_offset_stack
2024 .last()
2025 .copied()
2026 .unwrap_or_default()
2027 }
2028
2029 /// Obtain the current element opacity. This method should only be called during the
2030 /// prepaint phase of element drawing.
2031 pub(crate) fn element_opacity(&self) -> f32 {
2032 debug_assert!(
2033 matches!(
2034 self.window.draw_phase,
2035 DrawPhase::Prepaint | DrawPhase::Paint
2036 ),
2037 "this method can only be called during prepaint, or paint"
2038 );
2039 self.window().element_opacity.unwrap_or(1.0)
2040 }
2041
2042 /// Obtain the current content mask. This method should only be called during element drawing.
2043 pub fn content_mask(&self) -> ContentMask<Pixels> {
2044 debug_assert!(
2045 matches!(
2046 self.window.draw_phase,
2047 DrawPhase::Prepaint | DrawPhase::Paint
2048 ),
2049 "this method can only be called during prepaint, or paint"
2050 );
2051 self.window()
2052 .content_mask_stack
2053 .last()
2054 .cloned()
2055 .unwrap_or_else(|| ContentMask {
2056 bounds: Bounds {
2057 origin: Point::default(),
2058 size: self.window().viewport_size,
2059 },
2060 })
2061 }
2062
2063 /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2064 /// This can be used within a custom element to distinguish multiple sets of child elements.
2065 pub fn with_element_namespace<R>(
2066 &mut self,
2067 element_id: impl Into<ElementId>,
2068 f: impl FnOnce(&mut Self) -> R,
2069 ) -> R {
2070 self.window.element_id_stack.push(element_id.into());
2071 let result = f(self);
2072 self.window.element_id_stack.pop();
2073 result
2074 }
2075
2076 /// Updates or initializes state for an element with the given id that lives across multiple
2077 /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2078 /// to the given closure. The state returned by the closure will be stored so it can be referenced
2079 /// when drawing the next frame. This method should only be called as part of element drawing.
2080 pub fn with_element_state<S, R>(
2081 &mut self,
2082 global_id: &GlobalElementId,
2083 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2084 ) -> R
2085 where
2086 S: 'static,
2087 {
2088 debug_assert!(
2089 matches!(
2090 self.window.draw_phase,
2091 DrawPhase::Prepaint | DrawPhase::Paint
2092 ),
2093 "this method can only be called during request_layout, prepaint, or paint"
2094 );
2095
2096 let key = (GlobalElementId(global_id.0.clone()), TypeId::of::<S>());
2097 self.window
2098 .next_frame
2099 .accessed_element_states
2100 .push((GlobalElementId(key.0.clone()), TypeId::of::<S>()));
2101
2102 if let Some(any) = self
2103 .window
2104 .next_frame
2105 .element_states
2106 .remove(&key)
2107 .or_else(|| self.window.rendered_frame.element_states.remove(&key))
2108 {
2109 let ElementStateBox {
2110 inner,
2111 #[cfg(debug_assertions)]
2112 type_name,
2113 } = any;
2114 // Using the extra inner option to avoid needing to reallocate a new box.
2115 let mut state_box = inner
2116 .downcast::<Option<S>>()
2117 .map_err(|_| {
2118 #[cfg(debug_assertions)]
2119 {
2120 anyhow::anyhow!(
2121 "invalid element state type for id, requested {:?}, actual: {:?}",
2122 std::any::type_name::<S>(),
2123 type_name
2124 )
2125 }
2126
2127 #[cfg(not(debug_assertions))]
2128 {
2129 anyhow::anyhow!(
2130 "invalid element state type for id, requested {:?}",
2131 std::any::type_name::<S>(),
2132 )
2133 }
2134 })
2135 .unwrap();
2136
2137 let state = state_box.take().expect(
2138 "reentrant call to with_element_state for the same state type and element id",
2139 );
2140 let (result, state) = f(Some(state), self);
2141 state_box.replace(state);
2142 self.window.next_frame.element_states.insert(
2143 key,
2144 ElementStateBox {
2145 inner: state_box,
2146 #[cfg(debug_assertions)]
2147 type_name,
2148 },
2149 );
2150 result
2151 } else {
2152 let (result, state) = f(None, self);
2153 self.window.next_frame.element_states.insert(
2154 key,
2155 ElementStateBox {
2156 inner: Box::new(Some(state)),
2157 #[cfg(debug_assertions)]
2158 type_name: std::any::type_name::<S>(),
2159 },
2160 );
2161 result
2162 }
2163 }
2164
2165 /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2166 /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2167 /// when the element is guaranteed to have an id.
2168 ///
2169 /// The first option means 'no ID provided'
2170 /// The second option means 'not yet initialized'
2171 pub fn with_optional_element_state<S, R>(
2172 &mut self,
2173 global_id: Option<&GlobalElementId>,
2174 f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2175 ) -> R
2176 where
2177 S: 'static,
2178 {
2179 debug_assert!(
2180 matches!(
2181 self.window.draw_phase,
2182 DrawPhase::Prepaint | DrawPhase::Paint
2183 ),
2184 "this method can only be called during request_layout, prepaint, or paint"
2185 );
2186
2187 if let Some(global_id) = global_id {
2188 self.with_element_state(global_id, |state, cx| {
2189 let (result, state) = f(Some(state), cx);
2190 let state =
2191 state.expect("you must return some state when you pass some element id");
2192 (result, state)
2193 })
2194 } else {
2195 let (result, state) = f(None, self);
2196 debug_assert!(
2197 state.is_none(),
2198 "you must not return an element state when passing None for the global id"
2199 );
2200 result
2201 }
2202 }
2203
2204 /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2205 /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2206 /// with higher values being drawn on top.
2207 ///
2208 /// This method should only be called as part of the prepaint phase of element drawing.
2209 pub fn defer_draw(
2210 &mut self,
2211 element: AnyElement,
2212 absolute_offset: Point<Pixels>,
2213 priority: usize,
2214 ) {
2215 let window = &mut self.window;
2216 debug_assert_eq!(
2217 window.draw_phase,
2218 DrawPhase::Prepaint,
2219 "this method can only be called during request_layout or prepaint"
2220 );
2221 let parent_node = window.next_frame.dispatch_tree.active_node_id().unwrap();
2222 window.next_frame.deferred_draws.push(DeferredDraw {
2223 parent_node,
2224 element_id_stack: window.element_id_stack.clone(),
2225 text_style_stack: window.text_style_stack.clone(),
2226 priority,
2227 element: Some(element),
2228 absolute_offset,
2229 prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2230 paint_range: PaintIndex::default()..PaintIndex::default(),
2231 });
2232 }
2233
2234 /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2235 /// of geometry that are non-overlapping and have the same draw order. This is typically used
2236 /// for performance reasons.
2237 ///
2238 /// This method should only be called as part of the paint phase of element drawing.
2239 pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2240 debug_assert_eq!(
2241 self.window.draw_phase,
2242 DrawPhase::Paint,
2243 "this method can only be called during paint"
2244 );
2245
2246 let scale_factor = self.scale_factor();
2247 let content_mask = self.content_mask();
2248 let clipped_bounds = bounds.intersect(&content_mask.bounds);
2249 if !clipped_bounds.is_empty() {
2250 self.window
2251 .next_frame
2252 .scene
2253 .push_layer(clipped_bounds.scale(scale_factor));
2254 }
2255
2256 let result = f(self);
2257
2258 if !clipped_bounds.is_empty() {
2259 self.window.next_frame.scene.pop_layer();
2260 }
2261
2262 result
2263 }
2264
2265 /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2266 ///
2267 /// This method should only be called as part of the paint phase of element drawing.
2268 pub fn paint_shadows(
2269 &mut self,
2270 bounds: Bounds<Pixels>,
2271 corner_radii: Corners<Pixels>,
2272 shadows: &[BoxShadow],
2273 ) {
2274 debug_assert_eq!(
2275 self.window.draw_phase,
2276 DrawPhase::Paint,
2277 "this method can only be called during paint"
2278 );
2279
2280 let scale_factor = self.scale_factor();
2281 let content_mask = self.content_mask();
2282 let opacity = self.element_opacity();
2283 for shadow in shadows {
2284 let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
2285 self.window.next_frame.scene.insert_primitive(Shadow {
2286 order: 0,
2287 blur_radius: shadow.blur_radius.scale(scale_factor),
2288 bounds: shadow_bounds.scale(scale_factor),
2289 content_mask: content_mask.scale(scale_factor),
2290 corner_radii: corner_radii.scale(scale_factor),
2291 color: shadow.color.opacity(opacity),
2292 });
2293 }
2294 }
2295
2296 /// Paint one or more quads into the scene for the next frame at the current stacking context.
2297 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2298 /// see [`fill`](crate::fill), [`outline`](crate::outline), and [`quad`](crate::quad) to construct this type.
2299 ///
2300 /// This method should only be called as part of the paint phase of element drawing.
2301 pub fn paint_quad(&mut self, quad: PaintQuad) {
2302 debug_assert_eq!(
2303 self.window.draw_phase,
2304 DrawPhase::Paint,
2305 "this method can only be called during paint"
2306 );
2307
2308 let scale_factor = self.scale_factor();
2309 let content_mask = self.content_mask();
2310 let opacity = self.element_opacity();
2311 self.window.next_frame.scene.insert_primitive(Quad {
2312 order: 0,
2313 pad: 0,
2314 bounds: quad.bounds.scale(scale_factor),
2315 content_mask: content_mask.scale(scale_factor),
2316 background: quad.background.opacity(opacity),
2317 border_color: quad.border_color.opacity(opacity),
2318 corner_radii: quad.corner_radii.scale(scale_factor),
2319 border_widths: quad.border_widths.scale(scale_factor),
2320 });
2321 }
2322
2323 /// Paint the given `Path` into the scene for the next frame at the current z-index.
2324 ///
2325 /// This method should only be called as part of the paint phase of element drawing.
2326 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
2327 debug_assert_eq!(
2328 self.window.draw_phase,
2329 DrawPhase::Paint,
2330 "this method can only be called during paint"
2331 );
2332
2333 let scale_factor = self.scale_factor();
2334 let content_mask = self.content_mask();
2335 let opacity = self.element_opacity();
2336 path.content_mask = content_mask;
2337 let color: Background = color.into();
2338 path.color = color.opacity(opacity);
2339 self.window
2340 .next_frame
2341 .scene
2342 .insert_primitive(path.scale(scale_factor));
2343 }
2344
2345 /// Paint an underline into the scene for the next frame at the current z-index.
2346 ///
2347 /// This method should only be called as part of the paint phase of element drawing.
2348 pub fn paint_underline(
2349 &mut self,
2350 origin: Point<Pixels>,
2351 width: Pixels,
2352 style: &UnderlineStyle,
2353 ) {
2354 debug_assert_eq!(
2355 self.window.draw_phase,
2356 DrawPhase::Paint,
2357 "this method can only be called during paint"
2358 );
2359
2360 let scale_factor = self.scale_factor();
2361 let height = if style.wavy {
2362 style.thickness * 3.
2363 } else {
2364 style.thickness
2365 };
2366 let bounds = Bounds {
2367 origin,
2368 size: size(width, height),
2369 };
2370 let content_mask = self.content_mask();
2371 let element_opacity = self.element_opacity();
2372
2373 self.window.next_frame.scene.insert_primitive(Underline {
2374 order: 0,
2375 pad: 0,
2376 bounds: bounds.scale(scale_factor),
2377 content_mask: content_mask.scale(scale_factor),
2378 color: style.color.unwrap_or_default().opacity(element_opacity),
2379 thickness: style.thickness.scale(scale_factor),
2380 wavy: style.wavy,
2381 });
2382 }
2383
2384 /// Paint a strikethrough into the scene for the next frame at the current z-index.
2385 ///
2386 /// This method should only be called as part of the paint phase of element drawing.
2387 pub fn paint_strikethrough(
2388 &mut self,
2389 origin: Point<Pixels>,
2390 width: Pixels,
2391 style: &StrikethroughStyle,
2392 ) {
2393 debug_assert_eq!(
2394 self.window.draw_phase,
2395 DrawPhase::Paint,
2396 "this method can only be called during paint"
2397 );
2398
2399 let scale_factor = self.scale_factor();
2400 let height = style.thickness;
2401 let bounds = Bounds {
2402 origin,
2403 size: size(width, height),
2404 };
2405 let content_mask = self.content_mask();
2406 let opacity = self.element_opacity();
2407
2408 self.window.next_frame.scene.insert_primitive(Underline {
2409 order: 0,
2410 pad: 0,
2411 bounds: bounds.scale(scale_factor),
2412 content_mask: content_mask.scale(scale_factor),
2413 thickness: style.thickness.scale(scale_factor),
2414 color: style.color.unwrap_or_default().opacity(opacity),
2415 wavy: false,
2416 });
2417 }
2418
2419 /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
2420 ///
2421 /// The y component of the origin is the baseline of the glyph.
2422 /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2423 /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2424 /// This method is only useful if you need to paint a single glyph that has already been shaped.
2425 ///
2426 /// This method should only be called as part of the paint phase of element drawing.
2427 pub fn paint_glyph(
2428 &mut self,
2429 origin: Point<Pixels>,
2430 font_id: FontId,
2431 glyph_id: GlyphId,
2432 font_size: Pixels,
2433 color: Hsla,
2434 ) -> Result<()> {
2435 debug_assert_eq!(
2436 self.window.draw_phase,
2437 DrawPhase::Paint,
2438 "this method can only be called during paint"
2439 );
2440
2441 let element_opacity = self.element_opacity();
2442 let scale_factor = self.scale_factor();
2443 let glyph_origin = origin.scale(scale_factor);
2444 let subpixel_variant = Point {
2445 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2446 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2447 };
2448 let params = RenderGlyphParams {
2449 font_id,
2450 glyph_id,
2451 font_size,
2452 subpixel_variant,
2453 scale_factor,
2454 is_emoji: false,
2455 };
2456
2457 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
2458 if !raster_bounds.is_zero() {
2459 let tile = self
2460 .window
2461 .sprite_atlas
2462 .get_or_insert_with(¶ms.clone().into(), &mut || {
2463 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
2464 Ok(Some((size, Cow::Owned(bytes))))
2465 })?
2466 .expect("Callback above only errors or returns Some");
2467 let bounds = Bounds {
2468 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2469 size: tile.bounds.size.map(Into::into),
2470 };
2471 let content_mask = self.content_mask().scale(scale_factor);
2472 self.window
2473 .next_frame
2474 .scene
2475 .insert_primitive(MonochromeSprite {
2476 order: 0,
2477 pad: 0,
2478 bounds,
2479 content_mask,
2480 color: color.opacity(element_opacity),
2481 tile,
2482 transformation: TransformationMatrix::unit(),
2483 });
2484 }
2485 Ok(())
2486 }
2487
2488 /// Paints an emoji glyph into the scene for the next frame at the current z-index.
2489 ///
2490 /// The y component of the origin is the baseline of the glyph.
2491 /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2492 /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2493 /// This method is only useful if you need to paint a single emoji that has already been shaped.
2494 ///
2495 /// This method should only be called as part of the paint phase of element drawing.
2496 pub fn paint_emoji(
2497 &mut self,
2498 origin: Point<Pixels>,
2499 font_id: FontId,
2500 glyph_id: GlyphId,
2501 font_size: Pixels,
2502 ) -> Result<()> {
2503 debug_assert_eq!(
2504 self.window.draw_phase,
2505 DrawPhase::Paint,
2506 "this method can only be called during paint"
2507 );
2508
2509 let scale_factor = self.scale_factor();
2510 let glyph_origin = origin.scale(scale_factor);
2511 let params = RenderGlyphParams {
2512 font_id,
2513 glyph_id,
2514 font_size,
2515 // We don't render emojis with subpixel variants.
2516 subpixel_variant: Default::default(),
2517 scale_factor,
2518 is_emoji: true,
2519 };
2520
2521 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
2522 if !raster_bounds.is_zero() {
2523 let tile = self
2524 .window
2525 .sprite_atlas
2526 .get_or_insert_with(¶ms.clone().into(), &mut || {
2527 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
2528 Ok(Some((size, Cow::Owned(bytes))))
2529 })?
2530 .expect("Callback above only errors or returns Some");
2531
2532 let bounds = Bounds {
2533 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2534 size: tile.bounds.size.map(Into::into),
2535 };
2536 let content_mask = self.content_mask().scale(scale_factor);
2537 let opacity = self.element_opacity();
2538
2539 self.window
2540 .next_frame
2541 .scene
2542 .insert_primitive(PolychromeSprite {
2543 order: 0,
2544 pad: 0,
2545 grayscale: false,
2546 bounds,
2547 corner_radii: Default::default(),
2548 content_mask,
2549 tile,
2550 opacity,
2551 });
2552 }
2553 Ok(())
2554 }
2555
2556 /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
2557 ///
2558 /// This method should only be called as part of the paint phase of element drawing.
2559 pub fn paint_svg(
2560 &mut self,
2561 bounds: Bounds<Pixels>,
2562 path: SharedString,
2563 transformation: TransformationMatrix,
2564 color: Hsla,
2565 ) -> Result<()> {
2566 debug_assert_eq!(
2567 self.window.draw_phase,
2568 DrawPhase::Paint,
2569 "this method can only be called during paint"
2570 );
2571
2572 let element_opacity = self.element_opacity();
2573 let scale_factor = self.scale_factor();
2574 let bounds = bounds.scale(scale_factor);
2575 // Render the SVG at twice the size to get a higher quality result.
2576 let params = RenderSvgParams {
2577 path,
2578 size: bounds
2579 .size
2580 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
2581 };
2582
2583 let Some(tile) =
2584 self.window
2585 .sprite_atlas
2586 .get_or_insert_with(¶ms.clone().into(), &mut || {
2587 let Some(bytes) = self.svg_renderer.render(¶ms)? else {
2588 return Ok(None);
2589 };
2590 Ok(Some((params.size, Cow::Owned(bytes))))
2591 })?
2592 else {
2593 return Ok(());
2594 };
2595 let content_mask = self.content_mask().scale(scale_factor);
2596
2597 self.window
2598 .next_frame
2599 .scene
2600 .insert_primitive(MonochromeSprite {
2601 order: 0,
2602 pad: 0,
2603 bounds: bounds
2604 .map_origin(|origin| origin.floor())
2605 .map_size(|size| size.ceil()),
2606 content_mask,
2607 color: color.opacity(element_opacity),
2608 tile,
2609 transformation,
2610 });
2611
2612 Ok(())
2613 }
2614
2615 /// Paint an image into the scene for the next frame at the current z-index.
2616 /// This method will panic if the frame_index is not valid
2617 ///
2618 /// This method should only be called as part of the paint phase of element drawing.
2619 pub fn paint_image(
2620 &mut self,
2621 bounds: Bounds<Pixels>,
2622 corner_radii: Corners<Pixels>,
2623 data: Arc<RenderImage>,
2624 frame_index: usize,
2625 grayscale: bool,
2626 ) -> Result<()> {
2627 debug_assert_eq!(
2628 self.window.draw_phase,
2629 DrawPhase::Paint,
2630 "this method can only be called during paint"
2631 );
2632
2633 let scale_factor = self.scale_factor();
2634 let bounds = bounds.scale(scale_factor);
2635 let params = RenderImageParams {
2636 image_id: data.id,
2637 frame_index,
2638 };
2639
2640 let tile = self
2641 .window
2642 .sprite_atlas
2643 .get_or_insert_with(¶ms.clone().into(), &mut || {
2644 Ok(Some((
2645 data.size(frame_index),
2646 Cow::Borrowed(
2647 data.as_bytes(frame_index)
2648 .expect("It's the caller's job to pass a valid frame index"),
2649 ),
2650 )))
2651 })?
2652 .expect("Callback above only returns Some");
2653 let content_mask = self.content_mask().scale(scale_factor);
2654 let corner_radii = corner_radii.scale(scale_factor);
2655 let opacity = self.element_opacity();
2656
2657 self.window
2658 .next_frame
2659 .scene
2660 .insert_primitive(PolychromeSprite {
2661 order: 0,
2662 pad: 0,
2663 grayscale,
2664 bounds,
2665 content_mask,
2666 corner_radii,
2667 tile,
2668 opacity,
2669 });
2670 Ok(())
2671 }
2672
2673 /// Paint a surface into the scene for the next frame at the current z-index.
2674 ///
2675 /// This method should only be called as part of the paint phase of element drawing.
2676 #[cfg(target_os = "macos")]
2677 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
2678 use crate::PaintSurface;
2679
2680 debug_assert_eq!(
2681 self.window.draw_phase,
2682 DrawPhase::Paint,
2683 "this method can only be called during paint"
2684 );
2685
2686 let scale_factor = self.scale_factor();
2687 let bounds = bounds.scale(scale_factor);
2688 let content_mask = self.content_mask().scale(scale_factor);
2689 self.window.next_frame.scene.insert_primitive(PaintSurface {
2690 order: 0,
2691 bounds,
2692 content_mask,
2693 image_buffer,
2694 });
2695 }
2696
2697 /// Removes an image from the sprite atlas.
2698 pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
2699 for frame_index in 0..data.frame_count() {
2700 let params = RenderImageParams {
2701 image_id: data.id,
2702 frame_index,
2703 };
2704
2705 self.window.sprite_atlas.remove(¶ms.clone().into());
2706 }
2707
2708 Ok(())
2709 }
2710
2711 #[must_use]
2712 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
2713 /// layout is being requested, along with the layout ids of any children. This method is called during
2714 /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
2715 ///
2716 /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2717 pub fn request_layout(
2718 &mut self,
2719 style: Style,
2720 children: impl IntoIterator<Item = LayoutId>,
2721 ) -> LayoutId {
2722 debug_assert_eq!(
2723 self.window.draw_phase,
2724 DrawPhase::Prepaint,
2725 "this method can only be called during request_layout, or prepaint"
2726 );
2727
2728 self.app.layout_id_buffer.clear();
2729 self.app.layout_id_buffer.extend(children);
2730 let rem_size = self.rem_size();
2731
2732 self.window.layout_engine.as_mut().unwrap().request_layout(
2733 style,
2734 rem_size,
2735 &self.app.layout_id_buffer,
2736 )
2737 }
2738
2739 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
2740 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
2741 /// determine the element's size. One place this is used internally is when measuring text.
2742 ///
2743 /// The given closure is invoked at layout time with the known dimensions and available space and
2744 /// returns a `Size`.
2745 ///
2746 /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2747 pub fn request_measured_layout<
2748 F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut WindowContext) -> Size<Pixels>
2749 + 'static,
2750 >(
2751 &mut self,
2752 style: Style,
2753 measure: F,
2754 ) -> LayoutId {
2755 debug_assert_eq!(
2756 self.window.draw_phase,
2757 DrawPhase::Prepaint,
2758 "this method can only be called during request_layout, or prepaint"
2759 );
2760
2761 let rem_size = self.rem_size();
2762 self.window
2763 .layout_engine
2764 .as_mut()
2765 .unwrap()
2766 .request_measured_layout(style, rem_size, measure)
2767 }
2768
2769 /// Compute the layout for the given id within the given available space.
2770 /// This method is called for its side effect, typically by the framework prior to painting.
2771 /// After calling it, you can request the bounds of the given layout node id or any descendant.
2772 ///
2773 /// This method should only be called as part of the prepaint phase of element drawing.
2774 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
2775 debug_assert_eq!(
2776 self.window.draw_phase,
2777 DrawPhase::Prepaint,
2778 "this method can only be called during request_layout, or prepaint"
2779 );
2780
2781 let mut layout_engine = self.window.layout_engine.take().unwrap();
2782 layout_engine.compute_layout(layout_id, available_space, self);
2783 self.window.layout_engine = Some(layout_engine);
2784 }
2785
2786 /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
2787 /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
2788 ///
2789 /// This method should only be called as part of element drawing.
2790 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
2791 debug_assert_eq!(
2792 self.window.draw_phase,
2793 DrawPhase::Prepaint,
2794 "this method can only be called during request_layout, prepaint, or paint"
2795 );
2796
2797 let mut bounds = self
2798 .window
2799 .layout_engine
2800 .as_mut()
2801 .unwrap()
2802 .layout_bounds(layout_id)
2803 .map(Into::into);
2804 bounds.origin += self.element_offset();
2805 bounds
2806 }
2807
2808 /// This method should be called during `prepaint`. You can use
2809 /// the returned [Hitbox] during `paint` or in an event handler
2810 /// to determine whether the inserted hitbox was the topmost.
2811 ///
2812 /// This method should only be called as part of the prepaint phase of element drawing.
2813 pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, opaque: bool) -> Hitbox {
2814 debug_assert_eq!(
2815 self.window.draw_phase,
2816 DrawPhase::Prepaint,
2817 "this method can only be called during prepaint"
2818 );
2819
2820 let content_mask = self.content_mask();
2821 let window = &mut self.window;
2822 let id = window.next_hitbox_id;
2823 window.next_hitbox_id.0 += 1;
2824 let hitbox = Hitbox {
2825 id,
2826 bounds,
2827 content_mask,
2828 opaque,
2829 };
2830 window.next_frame.hitboxes.push(hitbox.clone());
2831 hitbox
2832 }
2833
2834 /// Sets the key context for the current element. This context will be used to translate
2835 /// keybindings into actions.
2836 ///
2837 /// This method should only be called as part of the paint phase of element drawing.
2838 pub fn set_key_context(&mut self, context: KeyContext) {
2839 debug_assert_eq!(
2840 self.window.draw_phase,
2841 DrawPhase::Paint,
2842 "this method can only be called during paint"
2843 );
2844 self.window
2845 .next_frame
2846 .dispatch_tree
2847 .set_key_context(context);
2848 }
2849
2850 /// Sets the focus handle for the current element. This handle will be used to manage focus state
2851 /// and keyboard event dispatch for the element.
2852 ///
2853 /// This method should only be called as part of the prepaint phase of element drawing.
2854 pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle) {
2855 debug_assert_eq!(
2856 self.window.draw_phase,
2857 DrawPhase::Prepaint,
2858 "this method can only be called during prepaint"
2859 );
2860 if focus_handle.is_focused(self) {
2861 self.window.next_frame.focus = Some(focus_handle.id);
2862 }
2863 self.window
2864 .next_frame
2865 .dispatch_tree
2866 .set_focus_id(focus_handle.id);
2867 }
2868
2869 /// Sets the view id for the current element, which will be used to manage view caching.
2870 ///
2871 /// This method should only be called as part of element prepaint. We plan on removing this
2872 /// method eventually when we solve some issues that require us to construct editor elements
2873 /// directly instead of always using editors via views.
2874 pub fn set_view_id(&mut self, view_id: EntityId) {
2875 debug_assert_eq!(
2876 self.window.draw_phase,
2877 DrawPhase::Prepaint,
2878 "this method can only be called during prepaint"
2879 );
2880 self.window.next_frame.dispatch_tree.set_view_id(view_id);
2881 }
2882
2883 /// Get the last view id for the current element
2884 pub fn parent_view_id(&self) -> Option<EntityId> {
2885 self.window.next_frame.dispatch_tree.parent_view_id()
2886 }
2887
2888 /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
2889 /// platform to receive textual input with proper integration with concerns such
2890 /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
2891 /// rendered.
2892 ///
2893 /// This method should only be called as part of the paint phase of element drawing.
2894 ///
2895 /// [element_input_handler]: crate::ElementInputHandler
2896 pub fn handle_input(&mut self, focus_handle: &FocusHandle, input_handler: impl InputHandler) {
2897 debug_assert_eq!(
2898 self.window.draw_phase,
2899 DrawPhase::Paint,
2900 "this method can only be called during paint"
2901 );
2902
2903 if focus_handle.is_focused(self) {
2904 let cx = self.to_async();
2905 self.window
2906 .next_frame
2907 .input_handlers
2908 .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
2909 }
2910 }
2911
2912 /// Register a mouse event listener on the window for the next frame. The type of event
2913 /// is determined by the first parameter of the given listener. When the next frame is rendered
2914 /// the listener will be cleared.
2915 ///
2916 /// This method should only be called as part of the paint phase of element drawing.
2917 pub fn on_mouse_event<Event: MouseEvent>(
2918 &mut self,
2919 mut handler: impl FnMut(&Event, DispatchPhase, &mut WindowContext) + 'static,
2920 ) {
2921 debug_assert_eq!(
2922 self.window.draw_phase,
2923 DrawPhase::Paint,
2924 "this method can only be called during paint"
2925 );
2926
2927 self.window.next_frame.mouse_listeners.push(Some(Box::new(
2928 move |event: &dyn Any, phase: DispatchPhase, cx: &mut WindowContext<'_>| {
2929 if let Some(event) = event.downcast_ref() {
2930 handler(event, phase, cx)
2931 }
2932 },
2933 )));
2934 }
2935
2936 /// Register a key event listener on the window for the next frame. The type of event
2937 /// is determined by the first parameter of the given listener. When the next frame is rendered
2938 /// the listener will be cleared.
2939 ///
2940 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2941 /// a specific need to register a global listener.
2942 ///
2943 /// This method should only be called as part of the paint phase of element drawing.
2944 pub fn on_key_event<Event: KeyEvent>(
2945 &mut self,
2946 listener: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
2947 ) {
2948 debug_assert_eq!(
2949 self.window.draw_phase,
2950 DrawPhase::Paint,
2951 "this method can only be called during paint"
2952 );
2953
2954 self.window.next_frame.dispatch_tree.on_key_event(Rc::new(
2955 move |event: &dyn Any, phase, cx: &mut WindowContext<'_>| {
2956 if let Some(event) = event.downcast_ref::<Event>() {
2957 listener(event, phase, cx)
2958 }
2959 },
2960 ));
2961 }
2962
2963 /// Register a modifiers changed event listener on the window for the next frame.
2964 ///
2965 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2966 /// a specific need to register a global listener.
2967 ///
2968 /// This method should only be called as part of the paint phase of element drawing.
2969 pub fn on_modifiers_changed(
2970 &mut self,
2971 listener: impl Fn(&ModifiersChangedEvent, &mut WindowContext) + 'static,
2972 ) {
2973 debug_assert_eq!(
2974 self.window.draw_phase,
2975 DrawPhase::Paint,
2976 "this method can only be called during paint"
2977 );
2978
2979 self.window
2980 .next_frame
2981 .dispatch_tree
2982 .on_modifiers_changed(Rc::new(
2983 move |event: &ModifiersChangedEvent, cx: &mut WindowContext<'_>| {
2984 listener(event, cx)
2985 },
2986 ));
2987 }
2988
2989 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2990 /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
2991 /// Returns a subscription and persists until the subscription is dropped.
2992 pub fn on_focus_in(
2993 &mut self,
2994 handle: &FocusHandle,
2995 mut listener: impl FnMut(&mut WindowContext) + 'static,
2996 ) -> Subscription {
2997 let focus_id = handle.id;
2998 let (subscription, activate) =
2999 self.window.new_focus_listener(Box::new(move |event, cx| {
3000 if event.is_focus_in(focus_id) {
3001 listener(cx);
3002 }
3003 true
3004 }));
3005 self.app.defer(move |_| activate());
3006 subscription
3007 }
3008
3009 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3010 /// Returns a subscription and persists until the subscription is dropped.
3011 pub fn on_focus_out(
3012 &mut self,
3013 handle: &FocusHandle,
3014 mut listener: impl FnMut(FocusOutEvent, &mut WindowContext) + 'static,
3015 ) -> Subscription {
3016 let focus_id = handle.id;
3017 let (subscription, activate) =
3018 self.window.new_focus_listener(Box::new(move |event, cx| {
3019 if let Some(blurred_id) = event.previous_focus_path.last().copied() {
3020 if event.is_focus_out(focus_id) {
3021 let event = FocusOutEvent {
3022 blurred: WeakFocusHandle {
3023 id: blurred_id,
3024 handles: Arc::downgrade(&cx.window.focus_handles),
3025 },
3026 };
3027 listener(event, cx)
3028 }
3029 }
3030 true
3031 }));
3032 self.app.defer(move |_| activate());
3033 subscription
3034 }
3035
3036 fn reset_cursor_style(&self) {
3037 // Set the cursor only if we're the active window.
3038 if self.is_window_hovered() {
3039 let style = self
3040 .window
3041 .rendered_frame
3042 .cursor_styles
3043 .iter()
3044 .rev()
3045 .find(|request| request.hitbox_id.is_hovered(self))
3046 .map(|request| request.style)
3047 .unwrap_or(CursorStyle::Arrow);
3048 self.platform.set_cursor_style(style);
3049 }
3050 }
3051
3052 /// Dispatch a given keystroke as though the user had typed it.
3053 /// You can create a keystroke with Keystroke::parse("").
3054 pub fn dispatch_keystroke(&mut self, keystroke: Keystroke) -> bool {
3055 let keystroke = keystroke.with_simulated_ime();
3056 let result = self.dispatch_event(PlatformInput::KeyDown(KeyDownEvent {
3057 keystroke: keystroke.clone(),
3058 is_held: false,
3059 }));
3060 if !result.propagate {
3061 return true;
3062 }
3063
3064 if let Some(input) = keystroke.key_char {
3065 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
3066 input_handler.dispatch_input(&input, self);
3067 self.window.platform_window.set_input_handler(input_handler);
3068 return true;
3069 }
3070 }
3071
3072 false
3073 }
3074
3075 /// Represent this action as a key binding string, to display in the UI.
3076 pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3077 self.bindings_for_action(action)
3078 .into_iter()
3079 .next()
3080 .map(|binding| {
3081 binding
3082 .keystrokes()
3083 .iter()
3084 .map(ToString::to_string)
3085 .collect::<Vec<_>>()
3086 .join(" ")
3087 })
3088 .unwrap_or_else(|| action.name().to_string())
3089 }
3090
3091 /// Dispatch a mouse or keyboard event on the window.
3092 #[profiling::function]
3093 pub fn dispatch_event(&mut self, event: PlatformInput) -> DispatchEventResult {
3094 self.window.last_input_timestamp.set(Instant::now());
3095 // Handlers may set this to false by calling `stop_propagation`.
3096 self.app.propagate_event = true;
3097 // Handlers may set this to true by calling `prevent_default`.
3098 self.window.default_prevented = false;
3099
3100 let event = match event {
3101 // Track the mouse position with our own state, since accessing the platform
3102 // API for the mouse position can only occur on the main thread.
3103 PlatformInput::MouseMove(mouse_move) => {
3104 self.window.mouse_position = mouse_move.position;
3105 self.window.modifiers = mouse_move.modifiers;
3106 PlatformInput::MouseMove(mouse_move)
3107 }
3108 PlatformInput::MouseDown(mouse_down) => {
3109 self.window.mouse_position = mouse_down.position;
3110 self.window.modifiers = mouse_down.modifiers;
3111 PlatformInput::MouseDown(mouse_down)
3112 }
3113 PlatformInput::MouseUp(mouse_up) => {
3114 self.window.mouse_position = mouse_up.position;
3115 self.window.modifiers = mouse_up.modifiers;
3116 PlatformInput::MouseUp(mouse_up)
3117 }
3118 PlatformInput::MouseExited(mouse_exited) => {
3119 self.window.modifiers = mouse_exited.modifiers;
3120 PlatformInput::MouseExited(mouse_exited)
3121 }
3122 PlatformInput::ModifiersChanged(modifiers_changed) => {
3123 self.window.modifiers = modifiers_changed.modifiers;
3124 PlatformInput::ModifiersChanged(modifiers_changed)
3125 }
3126 PlatformInput::ScrollWheel(scroll_wheel) => {
3127 self.window.mouse_position = scroll_wheel.position;
3128 self.window.modifiers = scroll_wheel.modifiers;
3129 PlatformInput::ScrollWheel(scroll_wheel)
3130 }
3131 // Translate dragging and dropping of external files from the operating system
3132 // to internal drag and drop events.
3133 PlatformInput::FileDrop(file_drop) => match file_drop {
3134 FileDropEvent::Entered { position, paths } => {
3135 self.window.mouse_position = position;
3136 if self.active_drag.is_none() {
3137 self.active_drag = Some(AnyDrag {
3138 value: Arc::new(paths.clone()),
3139 view: self.new_view(|_| paths).into(),
3140 cursor_offset: position,
3141 });
3142 }
3143 PlatformInput::MouseMove(MouseMoveEvent {
3144 position,
3145 pressed_button: Some(MouseButton::Left),
3146 modifiers: Modifiers::default(),
3147 })
3148 }
3149 FileDropEvent::Pending { position } => {
3150 self.window.mouse_position = position;
3151 PlatformInput::MouseMove(MouseMoveEvent {
3152 position,
3153 pressed_button: Some(MouseButton::Left),
3154 modifiers: Modifiers::default(),
3155 })
3156 }
3157 FileDropEvent::Submit { position } => {
3158 self.activate(true);
3159 self.window.mouse_position = position;
3160 PlatformInput::MouseUp(MouseUpEvent {
3161 button: MouseButton::Left,
3162 position,
3163 modifiers: Modifiers::default(),
3164 click_count: 1,
3165 })
3166 }
3167 FileDropEvent::Exited => {
3168 self.active_drag.take();
3169 PlatformInput::FileDrop(FileDropEvent::Exited)
3170 }
3171 },
3172 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3173 };
3174
3175 if let Some(any_mouse_event) = event.mouse_event() {
3176 self.dispatch_mouse_event(any_mouse_event);
3177 } else if let Some(any_key_event) = event.keyboard_event() {
3178 self.dispatch_key_event(any_key_event);
3179 }
3180
3181 DispatchEventResult {
3182 propagate: self.app.propagate_event,
3183 default_prevented: self.window.default_prevented,
3184 }
3185 }
3186
3187 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
3188 let hit_test = self.window.rendered_frame.hit_test(self.mouse_position());
3189 if hit_test != self.window.mouse_hit_test {
3190 self.window.mouse_hit_test = hit_test;
3191 self.reset_cursor_style();
3192 }
3193
3194 let mut mouse_listeners = mem::take(&mut self.window.rendered_frame.mouse_listeners);
3195
3196 // Capture phase, events bubble from back to front. Handlers for this phase are used for
3197 // special purposes, such as detecting events outside of a given Bounds.
3198 for listener in &mut mouse_listeners {
3199 let listener = listener.as_mut().unwrap();
3200 listener(event, DispatchPhase::Capture, self);
3201 if !self.app.propagate_event {
3202 break;
3203 }
3204 }
3205
3206 // Bubble phase, where most normal handlers do their work.
3207 if self.app.propagate_event {
3208 for listener in mouse_listeners.iter_mut().rev() {
3209 let listener = listener.as_mut().unwrap();
3210 listener(event, DispatchPhase::Bubble, self);
3211 if !self.app.propagate_event {
3212 break;
3213 }
3214 }
3215 }
3216
3217 self.window.rendered_frame.mouse_listeners = mouse_listeners;
3218
3219 if self.has_active_drag() {
3220 if event.is::<MouseMoveEvent>() {
3221 // If this was a mouse move event, redraw the window so that the
3222 // active drag can follow the mouse cursor.
3223 self.refresh();
3224 } else if event.is::<MouseUpEvent>() {
3225 // If this was a mouse up event, cancel the active drag and redraw
3226 // the window.
3227 self.active_drag = None;
3228 self.refresh();
3229 }
3230 }
3231 }
3232
3233 fn dispatch_key_event(&mut self, event: &dyn Any) {
3234 if self.window.dirty.get() {
3235 self.draw();
3236 }
3237
3238 let node_id = self
3239 .window
3240 .focus
3241 .and_then(|focus_id| {
3242 self.window
3243 .rendered_frame
3244 .dispatch_tree
3245 .focusable_node_id(focus_id)
3246 })
3247 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3248
3249 let dispatch_path = self
3250 .window
3251 .rendered_frame
3252 .dispatch_tree
3253 .dispatch_path(node_id);
3254
3255 let mut keystroke: Option<Keystroke> = None;
3256
3257 if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3258 if event.modifiers.number_of_modifiers() == 0
3259 && self.window.pending_modifier.modifiers.number_of_modifiers() == 1
3260 && !self.window.pending_modifier.saw_keystroke
3261 {
3262 let key = match self.window.pending_modifier.modifiers {
3263 modifiers if modifiers.shift => Some("shift"),
3264 modifiers if modifiers.control => Some("control"),
3265 modifiers if modifiers.alt => Some("alt"),
3266 modifiers if modifiers.platform => Some("platform"),
3267 modifiers if modifiers.function => Some("function"),
3268 _ => None,
3269 };
3270 if let Some(key) = key {
3271 keystroke = Some(Keystroke {
3272 key: key.to_string(),
3273 key_char: None,
3274 modifiers: Modifiers::default(),
3275 });
3276 }
3277 }
3278
3279 if self.window.pending_modifier.modifiers.number_of_modifiers() == 0
3280 && event.modifiers.number_of_modifiers() == 1
3281 {
3282 self.window.pending_modifier.saw_keystroke = false
3283 }
3284 self.window.pending_modifier.modifiers = event.modifiers
3285 } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3286 self.window.pending_modifier.saw_keystroke = true;
3287 keystroke = Some(key_down_event.keystroke.clone());
3288 }
3289
3290 let Some(keystroke) = keystroke else {
3291 self.finish_dispatch_key_event(event, dispatch_path);
3292 return;
3293 };
3294
3295 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
3296 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus {
3297 currently_pending = PendingInput::default();
3298 }
3299
3300 let match_result = self.window.rendered_frame.dispatch_tree.dispatch_key(
3301 currently_pending.keystrokes,
3302 keystroke,
3303 &dispatch_path,
3304 );
3305 if !match_result.to_replay.is_empty() {
3306 self.replay_pending_input(match_result.to_replay)
3307 }
3308
3309 if !match_result.pending.is_empty() {
3310 currently_pending.keystrokes = match_result.pending;
3311 currently_pending.focus = self.window.focus;
3312 currently_pending.timer = Some(self.spawn(|mut cx| async move {
3313 cx.background_executor.timer(Duration::from_secs(1)).await;
3314 cx.update(move |cx| {
3315 let Some(currently_pending) = cx
3316 .window
3317 .pending_input
3318 .take()
3319 .filter(|pending| pending.focus == cx.window.focus)
3320 else {
3321 return;
3322 };
3323
3324 let dispatch_path = cx
3325 .window
3326 .rendered_frame
3327 .dispatch_tree
3328 .dispatch_path(node_id);
3329
3330 let to_replay = cx
3331 .window
3332 .rendered_frame
3333 .dispatch_tree
3334 .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
3335
3336 cx.replay_pending_input(to_replay)
3337 })
3338 .log_err();
3339 }));
3340 self.window.pending_input = Some(currently_pending);
3341 self.pending_input_changed();
3342 self.propagate_event = false;
3343 return;
3344 }
3345
3346 self.propagate_event = true;
3347 for binding in match_result.bindings {
3348 self.dispatch_action_on_node(node_id, binding.action.as_ref());
3349 if !self.propagate_event {
3350 self.dispatch_keystroke_observers(event, Some(binding.action));
3351 self.pending_input_changed();
3352 return;
3353 }
3354 }
3355
3356 self.finish_dispatch_key_event(event, dispatch_path);
3357 self.pending_input_changed();
3358 }
3359
3360 fn finish_dispatch_key_event(
3361 &mut self,
3362 event: &dyn Any,
3363 dispatch_path: SmallVec<[DispatchNodeId; 32]>,
3364 ) {
3365 self.dispatch_key_down_up_event(event, &dispatch_path);
3366 if !self.propagate_event {
3367 return;
3368 }
3369
3370 self.dispatch_modifiers_changed_event(event, &dispatch_path);
3371 if !self.propagate_event {
3372 return;
3373 }
3374
3375 self.dispatch_keystroke_observers(event, None);
3376 }
3377
3378 fn pending_input_changed(&mut self) {
3379 self.window
3380 .pending_input_observers
3381 .clone()
3382 .retain(&(), |callback| callback(self));
3383 }
3384
3385 fn dispatch_key_down_up_event(
3386 &mut self,
3387 event: &dyn Any,
3388 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3389 ) {
3390 // Capture phase
3391 for node_id in dispatch_path {
3392 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3393
3394 for key_listener in node.key_listeners.clone() {
3395 key_listener(event, DispatchPhase::Capture, self);
3396 if !self.propagate_event {
3397 return;
3398 }
3399 }
3400 }
3401
3402 // Bubble phase
3403 for node_id in dispatch_path.iter().rev() {
3404 // Handle low level key events
3405 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3406 for key_listener in node.key_listeners.clone() {
3407 key_listener(event, DispatchPhase::Bubble, self);
3408 if !self.propagate_event {
3409 return;
3410 }
3411 }
3412 }
3413 }
3414
3415 fn dispatch_modifiers_changed_event(
3416 &mut self,
3417 event: &dyn Any,
3418 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3419 ) {
3420 let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
3421 return;
3422 };
3423 for node_id in dispatch_path.iter().rev() {
3424 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3425 for listener in node.modifiers_changed_listeners.clone() {
3426 listener(event, self);
3427 if !self.propagate_event {
3428 return;
3429 }
3430 }
3431 }
3432 }
3433
3434 /// Determine whether a potential multi-stroke key binding is in progress on this window.
3435 pub fn has_pending_keystrokes(&self) -> bool {
3436 self.window.pending_input.is_some()
3437 }
3438
3439 pub(crate) fn clear_pending_keystrokes(&mut self) {
3440 self.window.pending_input.take();
3441 }
3442
3443 /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
3444 pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
3445 self.window
3446 .pending_input
3447 .as_ref()
3448 .map(|pending_input| pending_input.keystrokes.as_slice())
3449 }
3450
3451 fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>) {
3452 let node_id = self
3453 .window
3454 .focus
3455 .and_then(|focus_id| {
3456 self.window
3457 .rendered_frame
3458 .dispatch_tree
3459 .focusable_node_id(focus_id)
3460 })
3461 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3462
3463 let dispatch_path = self
3464 .window
3465 .rendered_frame
3466 .dispatch_tree
3467 .dispatch_path(node_id);
3468
3469 'replay: for replay in replays {
3470 let event = KeyDownEvent {
3471 keystroke: replay.keystroke.clone(),
3472 is_held: false,
3473 };
3474
3475 self.propagate_event = true;
3476 for binding in replay.bindings {
3477 self.dispatch_action_on_node(node_id, binding.action.as_ref());
3478 if !self.propagate_event {
3479 self.dispatch_keystroke_observers(&event, Some(binding.action));
3480 continue 'replay;
3481 }
3482 }
3483
3484 self.dispatch_key_down_up_event(&event, &dispatch_path);
3485 if !self.propagate_event {
3486 continue 'replay;
3487 }
3488 if let Some(input) = replay.keystroke.key_char.as_ref().cloned() {
3489 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
3490 input_handler.dispatch_input(&input, self);
3491 self.window.platform_window.set_input_handler(input_handler)
3492 }
3493 }
3494 }
3495 }
3496
3497 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: &dyn Action) {
3498 let dispatch_path = self
3499 .window
3500 .rendered_frame
3501 .dispatch_tree
3502 .dispatch_path(node_id);
3503
3504 // Capture phase for global actions.
3505 self.propagate_event = true;
3506 if let Some(mut global_listeners) = self
3507 .global_action_listeners
3508 .remove(&action.as_any().type_id())
3509 {
3510 for listener in &global_listeners {
3511 listener(action.as_any(), DispatchPhase::Capture, self);
3512 if !self.propagate_event {
3513 break;
3514 }
3515 }
3516
3517 global_listeners.extend(
3518 self.global_action_listeners
3519 .remove(&action.as_any().type_id())
3520 .unwrap_or_default(),
3521 );
3522
3523 self.global_action_listeners
3524 .insert(action.as_any().type_id(), global_listeners);
3525 }
3526
3527 if !self.propagate_event {
3528 return;
3529 }
3530
3531 // Capture phase for window actions.
3532 for node_id in &dispatch_path {
3533 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3534 for DispatchActionListener {
3535 action_type,
3536 listener,
3537 } in node.action_listeners.clone()
3538 {
3539 let any_action = action.as_any();
3540 if action_type == any_action.type_id() {
3541 listener(any_action, DispatchPhase::Capture, self);
3542
3543 if !self.propagate_event {
3544 return;
3545 }
3546 }
3547 }
3548 }
3549
3550 // Bubble phase for window actions.
3551 for node_id in dispatch_path.iter().rev() {
3552 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3553 for DispatchActionListener {
3554 action_type,
3555 listener,
3556 } in node.action_listeners.clone()
3557 {
3558 let any_action = action.as_any();
3559 if action_type == any_action.type_id() {
3560 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
3561 listener(any_action, DispatchPhase::Bubble, self);
3562
3563 if !self.propagate_event {
3564 return;
3565 }
3566 }
3567 }
3568 }
3569
3570 // Bubble phase for global actions.
3571 if let Some(mut global_listeners) = self
3572 .global_action_listeners
3573 .remove(&action.as_any().type_id())
3574 {
3575 for listener in global_listeners.iter().rev() {
3576 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
3577
3578 listener(action.as_any(), DispatchPhase::Bubble, self);
3579 if !self.propagate_event {
3580 break;
3581 }
3582 }
3583
3584 global_listeners.extend(
3585 self.global_action_listeners
3586 .remove(&action.as_any().type_id())
3587 .unwrap_or_default(),
3588 );
3589
3590 self.global_action_listeners
3591 .insert(action.as_any().type_id(), global_listeners);
3592 }
3593 }
3594
3595 /// Register the given handler to be invoked whenever the global of the given type
3596 /// is updated.
3597 pub fn observe_global<G: Global>(
3598 &mut self,
3599 f: impl Fn(&mut WindowContext<'_>) + 'static,
3600 ) -> Subscription {
3601 let window_handle = self.window.handle;
3602 let (subscription, activate) = self.global_observers.insert(
3603 TypeId::of::<G>(),
3604 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
3605 );
3606 self.app.defer(move |_| activate());
3607 subscription
3608 }
3609
3610 /// Focus the current window and bring it to the foreground at the platform level.
3611 pub fn activate_window(&self) {
3612 self.window.platform_window.activate();
3613 }
3614
3615 /// Minimize the current window at the platform level.
3616 pub fn minimize_window(&self) {
3617 self.window.platform_window.minimize();
3618 }
3619
3620 /// Toggle full screen status on the current window at the platform level.
3621 pub fn toggle_fullscreen(&self) {
3622 self.window.platform_window.toggle_fullscreen();
3623 }
3624
3625 /// Updates the IME panel position suggestions for languages like japanese, chinese.
3626 pub fn invalidate_character_coordinates(&self) {
3627 self.on_next_frame(|cx| {
3628 if let Some(mut input_handler) = cx.window.platform_window.take_input_handler() {
3629 if let Some(bounds) = input_handler.selected_bounds(cx) {
3630 cx.window
3631 .platform_window
3632 .update_ime_position(bounds.scale(cx.scale_factor()));
3633 }
3634 cx.window.platform_window.set_input_handler(input_handler);
3635 }
3636 });
3637 }
3638
3639 /// Present a platform dialog.
3640 /// The provided message will be presented, along with buttons for each answer.
3641 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
3642 pub fn prompt(
3643 &mut self,
3644 level: PromptLevel,
3645 message: &str,
3646 detail: Option<&str>,
3647 answers: &[&str],
3648 ) -> oneshot::Receiver<usize> {
3649 let prompt_builder = self.app.prompt_builder.take();
3650 let Some(prompt_builder) = prompt_builder else {
3651 unreachable!("Re-entrant window prompting is not supported by GPUI");
3652 };
3653
3654 let receiver = match &prompt_builder {
3655 PromptBuilder::Default => self
3656 .window
3657 .platform_window
3658 .prompt(level, message, detail, answers)
3659 .unwrap_or_else(|| {
3660 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
3661 }),
3662 PromptBuilder::Custom(_) => {
3663 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
3664 }
3665 };
3666
3667 self.app.prompt_builder = Some(prompt_builder);
3668
3669 receiver
3670 }
3671
3672 fn build_custom_prompt(
3673 &mut self,
3674 prompt_builder: &PromptBuilder,
3675 level: PromptLevel,
3676 message: &str,
3677 detail: Option<&str>,
3678 answers: &[&str],
3679 ) -> oneshot::Receiver<usize> {
3680 let (sender, receiver) = oneshot::channel();
3681 let handle = PromptHandle::new(sender);
3682 let handle = (prompt_builder)(level, message, detail, answers, handle, self);
3683 self.window.prompt = Some(handle);
3684 receiver
3685 }
3686
3687 /// Returns the current context stack.
3688 pub fn context_stack(&self) -> Vec<KeyContext> {
3689 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
3690 let node_id = self
3691 .window
3692 .focus
3693 .and_then(|focus_id| dispatch_tree.focusable_node_id(focus_id))
3694 .unwrap_or_else(|| dispatch_tree.root_node_id());
3695
3696 dispatch_tree
3697 .dispatch_path(node_id)
3698 .iter()
3699 .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
3700 .collect()
3701 }
3702
3703 /// Returns all available actions for the focused element.
3704 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
3705 let node_id = self
3706 .window
3707 .focus
3708 .and_then(|focus_id| {
3709 self.window
3710 .rendered_frame
3711 .dispatch_tree
3712 .focusable_node_id(focus_id)
3713 })
3714 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3715
3716 let mut actions = self
3717 .window
3718 .rendered_frame
3719 .dispatch_tree
3720 .available_actions(node_id);
3721 for action_type in self.global_action_listeners.keys() {
3722 if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
3723 let action = self.actions.build_action_type(action_type).ok();
3724 if let Some(action) = action {
3725 actions.insert(ix, action);
3726 }
3727 }
3728 }
3729 actions
3730 }
3731
3732 /// Returns key bindings that invoke the given action on the currently focused element.
3733 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
3734 self.window
3735 .rendered_frame
3736 .dispatch_tree
3737 .bindings_for_action(
3738 action,
3739 &self.window.rendered_frame.dispatch_tree.context_stack,
3740 )
3741 }
3742
3743 /// Returns key bindings that invoke the given action on the currently focused element.
3744 pub fn all_bindings_for_input(&self, input: &[Keystroke]) -> Vec<KeyBinding> {
3745 RefCell::borrow(&self.keymap).all_bindings_for_input(input)
3746 }
3747
3748 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
3749 pub fn bindings_for_action_in(
3750 &self,
3751 action: &dyn Action,
3752 focus_handle: &FocusHandle,
3753 ) -> Vec<KeyBinding> {
3754 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
3755
3756 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
3757 return vec![];
3758 };
3759 let context_stack: Vec<_> = dispatch_tree
3760 .dispatch_path(node_id)
3761 .into_iter()
3762 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
3763 .collect();
3764 dispatch_tree.bindings_for_action(action, &context_stack)
3765 }
3766
3767 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
3768 pub fn listener_for<V: Render, E>(
3769 &self,
3770 view: &View<V>,
3771 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
3772 ) -> impl Fn(&E, &mut WindowContext) + 'static {
3773 let view = view.downgrade();
3774 move |e: &E, cx: &mut WindowContext| {
3775 view.update(cx, |view, cx| f(view, e, cx)).ok();
3776 }
3777 }
3778
3779 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
3780 pub fn handler_for<V: Render>(
3781 &self,
3782 view: &View<V>,
3783 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
3784 ) -> impl Fn(&mut WindowContext) {
3785 let view = view.downgrade();
3786 move |cx: &mut WindowContext| {
3787 view.update(cx, |view, cx| f(view, cx)).ok();
3788 }
3789 }
3790
3791 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
3792 /// If the callback returns false, the window won't be closed.
3793 pub fn on_window_should_close(&self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
3794 let mut this = self.to_async();
3795 self.window
3796 .platform_window
3797 .on_should_close(Box::new(move || this.update(|cx| f(cx)).unwrap_or(true)))
3798 }
3799
3800 /// Register an action listener on the window for the next frame. The type of action
3801 /// is determined by the first parameter of the given listener. When the next frame is rendered
3802 /// the listener will be cleared.
3803 ///
3804 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
3805 /// a specific need to register a global listener.
3806 pub fn on_action(
3807 &mut self,
3808 action_type: TypeId,
3809 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
3810 ) {
3811 self.window
3812 .next_frame
3813 .dispatch_tree
3814 .on_action(action_type, Rc::new(listener));
3815 }
3816
3817 /// Read information about the GPU backing this window.
3818 /// Currently returns None on Mac and Windows.
3819 pub fn gpu_specs(&self) -> Option<GPUSpecs> {
3820 self.window.platform_window.gpu_specs()
3821 }
3822}
3823
3824#[cfg(target_os = "windows")]
3825impl WindowContext<'_> {
3826 /// Returns the raw HWND handle for the window.
3827 pub fn get_raw_handle(&self) -> windows::Win32::Foundation::HWND {
3828 self.window.platform_window.get_raw_handle()
3829 }
3830}
3831
3832impl Context for WindowContext<'_> {
3833 type Result<T> = T;
3834
3835 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
3836 where
3837 T: 'static,
3838 {
3839 let slot = self.app.entities.reserve();
3840 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
3841 self.entities.insert(slot, model)
3842 }
3843
3844 fn reserve_model<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
3845 self.app.reserve_model()
3846 }
3847
3848 fn insert_model<T: 'static>(
3849 &mut self,
3850 reservation: crate::Reservation<T>,
3851 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
3852 ) -> Self::Result<Model<T>> {
3853 self.app.insert_model(reservation, build_model)
3854 }
3855
3856 fn update_model<T: 'static, R>(
3857 &mut self,
3858 model: &Model<T>,
3859 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
3860 ) -> R {
3861 let mut entity = self.entities.lease(model);
3862 let result = update(
3863 &mut *entity,
3864 &mut ModelContext::new(&mut *self.app, model.downgrade()),
3865 );
3866 self.entities.end_lease(entity);
3867 result
3868 }
3869
3870 fn read_model<T, R>(
3871 &self,
3872 handle: &Model<T>,
3873 read: impl FnOnce(&T, &AppContext) -> R,
3874 ) -> Self::Result<R>
3875 where
3876 T: 'static,
3877 {
3878 let entity = self.entities.read(handle);
3879 read(entity, &*self.app)
3880 }
3881
3882 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
3883 where
3884 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
3885 {
3886 if window == self.window.handle {
3887 let root_view = self.window.root_view.clone().unwrap();
3888 Ok(update(root_view, self))
3889 } else {
3890 window.update(self.app, update)
3891 }
3892 }
3893
3894 fn read_window<T, R>(
3895 &self,
3896 window: &WindowHandle<T>,
3897 read: impl FnOnce(View<T>, &AppContext) -> R,
3898 ) -> Result<R>
3899 where
3900 T: 'static,
3901 {
3902 if window.any_handle == self.window.handle {
3903 let root_view = self
3904 .window
3905 .root_view
3906 .clone()
3907 .unwrap()
3908 .downcast::<T>()
3909 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
3910 Ok(read(root_view, self))
3911 } else {
3912 self.app.read_window(window, read)
3913 }
3914 }
3915}
3916
3917impl VisualContext for WindowContext<'_> {
3918 fn new_view<V>(
3919 &mut self,
3920 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
3921 ) -> Self::Result<View<V>>
3922 where
3923 V: 'static + Render,
3924 {
3925 let slot = self.app.entities.reserve();
3926 let view = View {
3927 model: slot.clone(),
3928 };
3929 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
3930 let entity = build_view_state(&mut cx);
3931 cx.entities.insert(slot, entity);
3932
3933 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
3934 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
3935 cx.new_view_observers.clone().retain(&tid, |observer| {
3936 let any_view = view.clone();
3937 (observer)(any_view, cx);
3938 true
3939 });
3940 }
3941 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
3942
3943 view
3944 }
3945
3946 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
3947 fn update_view<T: 'static, R>(
3948 &mut self,
3949 view: &View<T>,
3950 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
3951 ) -> Self::Result<R> {
3952 let mut lease = self.app.entities.lease(&view.model);
3953 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
3954 let result = update(&mut *lease, &mut cx);
3955 cx.app.entities.end_lease(lease);
3956 result
3957 }
3958
3959 fn replace_root_view<V>(
3960 &mut self,
3961 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
3962 ) -> Self::Result<View<V>>
3963 where
3964 V: 'static + Render,
3965 {
3966 let view = self.new_view(build_view);
3967 self.window.root_view = Some(view.clone().into());
3968 self.refresh();
3969 view
3970 }
3971
3972 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
3973 self.update_view(view, |view, cx| {
3974 view.focus_handle(cx).clone().focus(cx);
3975 })
3976 }
3977
3978 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
3979 where
3980 V: ManagedView,
3981 {
3982 self.update_view(view, |_, cx| cx.emit(DismissEvent))
3983 }
3984}
3985
3986impl<'a> std::ops::Deref for WindowContext<'a> {
3987 type Target = AppContext;
3988
3989 fn deref(&self) -> &Self::Target {
3990 self.app
3991 }
3992}
3993
3994impl<'a> std::ops::DerefMut for WindowContext<'a> {
3995 fn deref_mut(&mut self) -> &mut Self::Target {
3996 self.app
3997 }
3998}
3999
4000impl<'a> Borrow<AppContext> for WindowContext<'a> {
4001 fn borrow(&self) -> &AppContext {
4002 self.app
4003 }
4004}
4005
4006impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
4007 fn borrow_mut(&mut self) -> &mut AppContext {
4008 self.app
4009 }
4010}
4011
4012/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
4013pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
4014 #[doc(hidden)]
4015 fn app_mut(&mut self) -> &mut AppContext {
4016 self.borrow_mut()
4017 }
4018
4019 #[doc(hidden)]
4020 fn app(&self) -> &AppContext {
4021 self.borrow()
4022 }
4023
4024 #[doc(hidden)]
4025 fn window(&self) -> &Window {
4026 self.borrow()
4027 }
4028
4029 #[doc(hidden)]
4030 fn window_mut(&mut self) -> &mut Window {
4031 self.borrow_mut()
4032 }
4033}
4034
4035impl Borrow<Window> for WindowContext<'_> {
4036 fn borrow(&self) -> &Window {
4037 self.window
4038 }
4039}
4040
4041impl BorrowMut<Window> for WindowContext<'_> {
4042 fn borrow_mut(&mut self) -> &mut Window {
4043 self.window
4044 }
4045}
4046
4047impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
4048
4049/// Provides access to application state that is specialized for a particular [`View`].
4050/// Allows you to interact with focus, emit events, etc.
4051/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
4052/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
4053pub struct ViewContext<'a, V> {
4054 window_cx: WindowContext<'a>,
4055 view: &'a View<V>,
4056}
4057
4058impl<V> Borrow<AppContext> for ViewContext<'_, V> {
4059 fn borrow(&self) -> &AppContext {
4060 &*self.window_cx.app
4061 }
4062}
4063
4064impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
4065 fn borrow_mut(&mut self) -> &mut AppContext {
4066 &mut *self.window_cx.app
4067 }
4068}
4069
4070impl<V> Borrow<Window> for ViewContext<'_, V> {
4071 fn borrow(&self) -> &Window {
4072 &*self.window_cx.window
4073 }
4074}
4075
4076impl<V> BorrowMut<Window> for ViewContext<'_, V> {
4077 fn borrow_mut(&mut self) -> &mut Window {
4078 &mut *self.window_cx.window
4079 }
4080}
4081
4082impl<'a, V: 'static> ViewContext<'a, V> {
4083 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
4084 Self {
4085 window_cx: WindowContext::new(app, window),
4086 view,
4087 }
4088 }
4089
4090 /// Get the entity_id of this view.
4091 pub fn entity_id(&self) -> EntityId {
4092 self.view.entity_id()
4093 }
4094
4095 /// Get the view pointer underlying this context.
4096 pub fn view(&self) -> &View<V> {
4097 self.view
4098 }
4099
4100 /// Get the model underlying this view.
4101 pub fn model(&self) -> &Model<V> {
4102 &self.view.model
4103 }
4104
4105 /// Access the underlying window context.
4106 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
4107 &mut self.window_cx
4108 }
4109
4110 /// Sets a given callback to be run on the next frame.
4111 pub fn on_next_frame(&self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
4112 where
4113 V: 'static,
4114 {
4115 let view = self.view().clone();
4116 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
4117 }
4118
4119 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
4120 /// that are currently on the stack to be returned to the app.
4121 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
4122 let view = self.view().downgrade();
4123 self.window_cx.defer(move |cx| {
4124 view.update(cx, f).ok();
4125 });
4126 }
4127
4128 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
4129 pub fn observe<V2, E>(
4130 &mut self,
4131 entity: &E,
4132 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
4133 ) -> Subscription
4134 where
4135 V2: 'static,
4136 V: 'static,
4137 E: Entity<V2>,
4138 {
4139 let view = self.view().downgrade();
4140 let entity_id = entity.entity_id();
4141 let entity = entity.downgrade();
4142 let window_handle = self.window.handle;
4143 self.app.new_observer(
4144 entity_id,
4145 Box::new(move |cx| {
4146 window_handle
4147 .update(cx, |_, cx| {
4148 if let Some(handle) = E::upgrade_from(&entity) {
4149 view.update(cx, |this, cx| on_notify(this, handle, cx))
4150 .is_ok()
4151 } else {
4152 false
4153 }
4154 })
4155 .unwrap_or(false)
4156 }),
4157 )
4158 }
4159
4160 /// Subscribe to events emitted by another model or view.
4161 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
4162 /// 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.
4163 pub fn subscribe<V2, E, Evt>(
4164 &mut self,
4165 entity: &E,
4166 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
4167 ) -> Subscription
4168 where
4169 V2: EventEmitter<Evt>,
4170 E: Entity<V2>,
4171 Evt: 'static,
4172 {
4173 let view = self.view().downgrade();
4174 let entity_id = entity.entity_id();
4175 let handle = entity.downgrade();
4176 let window_handle = self.window.handle;
4177 self.app.new_subscription(
4178 entity_id,
4179 (
4180 TypeId::of::<Evt>(),
4181 Box::new(move |event, cx| {
4182 window_handle
4183 .update(cx, |_, cx| {
4184 if let Some(handle) = E::upgrade_from(&handle) {
4185 let event = event.downcast_ref().expect("invalid event type");
4186 view.update(cx, |this, cx| on_event(this, handle, event, cx))
4187 .is_ok()
4188 } else {
4189 false
4190 }
4191 })
4192 .unwrap_or(false)
4193 }),
4194 ),
4195 )
4196 }
4197
4198 /// Register a callback to be invoked when the view is released.
4199 ///
4200 /// The callback receives a handle to the view's window. This handle may be
4201 /// invalid, if the window was closed before the view was released.
4202 pub fn on_release(
4203 &self,
4204 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
4205 ) -> Subscription {
4206 let window_handle = self.window.handle;
4207 let (subscription, activate) = self.app.release_listeners.insert(
4208 self.view.model.entity_id,
4209 Box::new(move |this, cx| {
4210 let this = this.downcast_mut().expect("invalid entity type");
4211 on_release(this, window_handle, cx)
4212 }),
4213 );
4214 activate();
4215 subscription
4216 }
4217
4218 /// Register a callback to be invoked when the given Model or View is released.
4219 pub fn observe_release<V2, E>(
4220 &self,
4221 entity: &E,
4222 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
4223 ) -> Subscription
4224 where
4225 V: 'static,
4226 V2: 'static,
4227 E: Entity<V2>,
4228 {
4229 let view = self.view().downgrade();
4230 let entity_id = entity.entity_id();
4231 let window_handle = self.window.handle;
4232 let (subscription, activate) = self.app.release_listeners.insert(
4233 entity_id,
4234 Box::new(move |entity, cx| {
4235 let entity = entity.downcast_mut().expect("invalid entity type");
4236 let _ = window_handle.update(cx, |_, cx| {
4237 view.update(cx, |this, cx| on_release(this, entity, cx))
4238 });
4239 }),
4240 );
4241 activate();
4242 subscription
4243 }
4244
4245 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
4246 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
4247 pub fn notify(&mut self) {
4248 self.window_cx.notify(Some(self.view.entity_id()));
4249 }
4250
4251 /// Register a callback to be invoked when the window is resized.
4252 pub fn observe_window_bounds(
4253 &self,
4254 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4255 ) -> Subscription {
4256 let view = self.view.downgrade();
4257 let (subscription, activate) = self.window.bounds_observers.insert(
4258 (),
4259 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4260 );
4261 activate();
4262 subscription
4263 }
4264
4265 /// Register a callback to be invoked when the window is activated or deactivated.
4266 pub fn observe_window_activation(
4267 &self,
4268 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4269 ) -> Subscription {
4270 let view = self.view.downgrade();
4271 let (subscription, activate) = self.window.activation_observers.insert(
4272 (),
4273 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4274 );
4275 activate();
4276 subscription
4277 }
4278
4279 /// Registers a callback to be invoked when the window appearance changes.
4280 pub fn observe_window_appearance(
4281 &self,
4282 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4283 ) -> Subscription {
4284 let view = self.view.downgrade();
4285 let (subscription, activate) = self.window.appearance_observers.insert(
4286 (),
4287 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4288 );
4289 activate();
4290 subscription
4291 }
4292
4293 /// Register a callback to be invoked when a keystroke is received by the application
4294 /// in any window. Note that this fires after all other action and event mechanisms have resolved
4295 /// and that this API will not be invoked if the event's propagation is stopped.
4296 pub fn observe_keystrokes(
4297 &mut self,
4298 mut f: impl FnMut(&mut V, &KeystrokeEvent, &mut ViewContext<V>) + 'static,
4299 ) -> Subscription {
4300 fn inner(
4301 keystroke_observers: &SubscriberSet<(), KeystrokeObserver>,
4302 handler: KeystrokeObserver,
4303 ) -> Subscription {
4304 let (subscription, activate) = keystroke_observers.insert((), handler);
4305 activate();
4306 subscription
4307 }
4308
4309 let view = self.view.downgrade();
4310 inner(
4311 &mut self.keystroke_observers,
4312 Box::new(move |event, cx| {
4313 if let Some(view) = view.upgrade() {
4314 view.update(cx, |view, cx| f(view, event, cx));
4315 true
4316 } else {
4317 false
4318 }
4319 }),
4320 )
4321 }
4322
4323 /// Register a callback to be invoked when the window's pending input changes.
4324 pub fn observe_pending_input(
4325 &self,
4326 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4327 ) -> Subscription {
4328 let view = self.view.downgrade();
4329 let (subscription, activate) = self.window.pending_input_observers.insert(
4330 (),
4331 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4332 );
4333 activate();
4334 subscription
4335 }
4336
4337 /// Register a listener to be called when the given focus handle receives focus.
4338 /// Returns a subscription and persists until the subscription is dropped.
4339 pub fn on_focus(
4340 &mut self,
4341 handle: &FocusHandle,
4342 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4343 ) -> Subscription {
4344 let view = self.view.downgrade();
4345 let focus_id = handle.id;
4346 let (subscription, activate) =
4347 self.window.new_focus_listener(Box::new(move |event, cx| {
4348 view.update(cx, |view, cx| {
4349 if event.previous_focus_path.last() != Some(&focus_id)
4350 && event.current_focus_path.last() == Some(&focus_id)
4351 {
4352 listener(view, cx)
4353 }
4354 })
4355 .is_ok()
4356 }));
4357 self.app.defer(|_| activate());
4358 subscription
4359 }
4360
4361 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
4362 /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
4363 /// Returns a subscription and persists until the subscription is dropped.
4364 pub fn on_focus_in(
4365 &mut self,
4366 handle: &FocusHandle,
4367 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4368 ) -> Subscription {
4369 let view = self.view.downgrade();
4370 let focus_id = handle.id;
4371 let (subscription, activate) =
4372 self.window.new_focus_listener(Box::new(move |event, cx| {
4373 view.update(cx, |view, cx| {
4374 if event.is_focus_in(focus_id) {
4375 listener(view, cx)
4376 }
4377 })
4378 .is_ok()
4379 }));
4380 self.app.defer(move |_| activate());
4381 subscription
4382 }
4383
4384 /// Register a listener to be called when the given focus handle loses focus.
4385 /// Returns a subscription and persists until the subscription is dropped.
4386 pub fn on_blur(
4387 &mut self,
4388 handle: &FocusHandle,
4389 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4390 ) -> Subscription {
4391 let view = self.view.downgrade();
4392 let focus_id = handle.id;
4393 let (subscription, activate) =
4394 self.window.new_focus_listener(Box::new(move |event, cx| {
4395 view.update(cx, |view, cx| {
4396 if event.previous_focus_path.last() == Some(&focus_id)
4397 && event.current_focus_path.last() != Some(&focus_id)
4398 {
4399 listener(view, cx)
4400 }
4401 })
4402 .is_ok()
4403 }));
4404 self.app.defer(move |_| activate());
4405 subscription
4406 }
4407
4408 /// Register a listener to be called when nothing in the window has focus.
4409 /// This typically happens when the node that was focused is removed from the tree,
4410 /// and this callback lets you chose a default place to restore the users focus.
4411 /// Returns a subscription and persists until the subscription is dropped.
4412 pub fn on_focus_lost(
4413 &self,
4414 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4415 ) -> Subscription {
4416 let view = self.view.downgrade();
4417 let (subscription, activate) = self.window.focus_lost_listeners.insert(
4418 (),
4419 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
4420 );
4421 activate();
4422 subscription
4423 }
4424
4425 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
4426 /// Returns a subscription and persists until the subscription is dropped.
4427 pub fn on_focus_out(
4428 &mut self,
4429 handle: &FocusHandle,
4430 mut listener: impl FnMut(&mut V, FocusOutEvent, &mut ViewContext<V>) + 'static,
4431 ) -> Subscription {
4432 let view = self.view.downgrade();
4433 let focus_id = handle.id;
4434 let (subscription, activate) =
4435 self.window.new_focus_listener(Box::new(move |event, cx| {
4436 view.update(cx, |view, cx| {
4437 if let Some(blurred_id) = event.previous_focus_path.last().copied() {
4438 if event.is_focus_out(focus_id) {
4439 let event = FocusOutEvent {
4440 blurred: WeakFocusHandle {
4441 id: blurred_id,
4442 handles: Arc::downgrade(&cx.window.focus_handles),
4443 },
4444 };
4445 listener(view, event, cx)
4446 }
4447 }
4448 })
4449 .is_ok()
4450 }));
4451 self.app.defer(move |_| activate());
4452 subscription
4453 }
4454
4455 /// Schedule a future to be run asynchronously.
4456 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
4457 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
4458 /// The returned future will be polled on the main thread.
4459 pub fn spawn<Fut, R>(&self, f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut) -> Task<R>
4460 where
4461 R: 'static,
4462 Fut: Future<Output = R> + 'static,
4463 {
4464 let view = self.view().downgrade();
4465 self.window_cx.spawn(|cx| f(view, cx))
4466 }
4467
4468 /// Register a callback to be invoked when the given global state changes.
4469 pub fn observe_global<G: Global>(
4470 &mut self,
4471 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
4472 ) -> Subscription {
4473 let window_handle = self.window.handle;
4474 let view = self.view().downgrade();
4475 let (subscription, activate) = self.global_observers.insert(
4476 TypeId::of::<G>(),
4477 Box::new(move |cx| {
4478 window_handle
4479 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
4480 .unwrap_or(false)
4481 }),
4482 );
4483 self.app.defer(move |_| activate());
4484 subscription
4485 }
4486
4487 /// Register a callback to be invoked when the given Action type is dispatched to the window.
4488 pub fn on_action(
4489 &mut self,
4490 action_type: TypeId,
4491 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
4492 ) {
4493 let handle = self.view().clone();
4494 self.window_cx
4495 .on_action(action_type, move |action, phase, cx| {
4496 handle.update(cx, |view, cx| {
4497 listener(view, action, phase, cx);
4498 })
4499 });
4500 }
4501
4502 /// Emit an event to be handled by any other views that have subscribed via [ViewContext::subscribe].
4503 pub fn emit<Evt>(&mut self, event: Evt)
4504 where
4505 Evt: 'static,
4506 V: EventEmitter<Evt>,
4507 {
4508 let emitter = self.view.model.entity_id;
4509 self.app.push_effect(Effect::Emit {
4510 emitter,
4511 event_type: TypeId::of::<Evt>(),
4512 event: Box::new(event),
4513 });
4514 }
4515
4516 /// Move focus to the current view, assuming it implements [`FocusableView`].
4517 pub fn focus_self(&mut self)
4518 where
4519 V: FocusableView,
4520 {
4521 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
4522 }
4523
4524 /// Convenience method for accessing view state in an event callback.
4525 ///
4526 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
4527 /// but it's often useful to be able to access view state in these
4528 /// callbacks. This method provides a convenient way to do so.
4529 pub fn listener<E: ?Sized>(
4530 &self,
4531 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
4532 ) -> impl Fn(&E, &mut WindowContext) + 'static {
4533 let view = self.view().downgrade();
4534 move |e: &E, cx: &mut WindowContext| {
4535 view.update(cx, |view, cx| f(view, e, cx)).ok();
4536 }
4537 }
4538}
4539
4540impl<V> Context for ViewContext<'_, V> {
4541 type Result<U> = U;
4542
4543 fn new_model<T: 'static>(
4544 &mut self,
4545 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
4546 ) -> Model<T> {
4547 self.window_cx.new_model(build_model)
4548 }
4549
4550 fn reserve_model<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
4551 self.window_cx.reserve_model()
4552 }
4553
4554 fn insert_model<T: 'static>(
4555 &mut self,
4556 reservation: crate::Reservation<T>,
4557 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
4558 ) -> Self::Result<Model<T>> {
4559 self.window_cx.insert_model(reservation, build_model)
4560 }
4561
4562 fn update_model<T: 'static, R>(
4563 &mut self,
4564 model: &Model<T>,
4565 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
4566 ) -> R {
4567 self.window_cx.update_model(model, update)
4568 }
4569
4570 fn read_model<T, R>(
4571 &self,
4572 handle: &Model<T>,
4573 read: impl FnOnce(&T, &AppContext) -> R,
4574 ) -> Self::Result<R>
4575 where
4576 T: 'static,
4577 {
4578 self.window_cx.read_model(handle, read)
4579 }
4580
4581 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
4582 where
4583 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
4584 {
4585 self.window_cx.update_window(window, update)
4586 }
4587
4588 fn read_window<T, R>(
4589 &self,
4590 window: &WindowHandle<T>,
4591 read: impl FnOnce(View<T>, &AppContext) -> R,
4592 ) -> Result<R>
4593 where
4594 T: 'static,
4595 {
4596 self.window_cx.read_window(window, read)
4597 }
4598}
4599
4600impl<V: 'static> VisualContext for ViewContext<'_, V> {
4601 fn new_view<W: Render + 'static>(
4602 &mut self,
4603 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
4604 ) -> Self::Result<View<W>> {
4605 self.window_cx.new_view(build_view_state)
4606 }
4607
4608 fn update_view<V2: 'static, R>(
4609 &mut self,
4610 view: &View<V2>,
4611 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
4612 ) -> Self::Result<R> {
4613 self.window_cx.update_view(view, update)
4614 }
4615
4616 fn replace_root_view<W>(
4617 &mut self,
4618 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
4619 ) -> Self::Result<View<W>>
4620 where
4621 W: 'static + Render,
4622 {
4623 self.window_cx.replace_root_view(build_view)
4624 }
4625
4626 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
4627 self.window_cx.focus_view(view)
4628 }
4629
4630 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
4631 self.window_cx.dismiss_view(view)
4632 }
4633}
4634
4635impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
4636 type Target = WindowContext<'a>;
4637
4638 fn deref(&self) -> &Self::Target {
4639 &self.window_cx
4640 }
4641}
4642
4643impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
4644 fn deref_mut(&mut self) -> &mut Self::Target {
4645 &mut self.window_cx
4646 }
4647}
4648
4649// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4650slotmap::new_key_type! {
4651 /// A unique identifier for a window.
4652 pub struct WindowId;
4653}
4654
4655impl WindowId {
4656 /// Converts this window ID to a `u64`.
4657 pub fn as_u64(&self) -> u64 {
4658 self.0.as_ffi()
4659 }
4660}
4661
4662impl From<u64> for WindowId {
4663 fn from(value: u64) -> Self {
4664 WindowId(slotmap::KeyData::from_ffi(value))
4665 }
4666}
4667
4668/// A handle to a window with a specific root view type.
4669/// Note that this does not keep the window alive on its own.
4670#[derive(Deref, DerefMut)]
4671pub struct WindowHandle<V> {
4672 #[deref]
4673 #[deref_mut]
4674 pub(crate) any_handle: AnyWindowHandle,
4675 state_type: PhantomData<V>,
4676}
4677
4678impl<V: 'static + Render> WindowHandle<V> {
4679 /// Creates a new handle from a window ID.
4680 /// This does not check if the root type of the window is `V`.
4681 pub fn new(id: WindowId) -> Self {
4682 WindowHandle {
4683 any_handle: AnyWindowHandle {
4684 id,
4685 state_type: TypeId::of::<V>(),
4686 },
4687 state_type: PhantomData,
4688 }
4689 }
4690
4691 /// Get the root view out of this window.
4692 ///
4693 /// This will fail if the window is closed or if the root view's type does not match `V`.
4694 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
4695 where
4696 C: Context,
4697 {
4698 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
4699 root_view
4700 .downcast::<V>()
4701 .map_err(|_| anyhow!("the type of the window's root view has changed"))
4702 }))
4703 }
4704
4705 /// Updates the root view of this window.
4706 ///
4707 /// This will fail if the window has been closed or if the root view's type does not match
4708 pub fn update<C, R>(
4709 &self,
4710 cx: &mut C,
4711 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
4712 ) -> Result<R>
4713 where
4714 C: Context,
4715 {
4716 cx.update_window(self.any_handle, |root_view, cx| {
4717 let view = root_view
4718 .downcast::<V>()
4719 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4720 Ok(cx.update_view(&view, update))
4721 })?
4722 }
4723
4724 /// Read the root view out of this window.
4725 ///
4726 /// This will fail if the window is closed or if the root view's type does not match `V`.
4727 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
4728 let x = cx
4729 .windows
4730 .get(self.id)
4731 .and_then(|window| {
4732 window
4733 .as_ref()
4734 .and_then(|window| window.root_view.clone())
4735 .map(|root_view| root_view.downcast::<V>())
4736 })
4737 .ok_or_else(|| anyhow!("window not found"))?
4738 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4739
4740 Ok(x.read(cx))
4741 }
4742
4743 /// Read the root view out of this window, with a callback
4744 ///
4745 /// This will fail if the window is closed or if the root view's type does not match `V`.
4746 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
4747 where
4748 C: Context,
4749 {
4750 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4751 }
4752
4753 /// Read the root view pointer off of this window.
4754 ///
4755 /// This will fail if the window is closed or if the root view's type does not match `V`.
4756 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
4757 where
4758 C: Context,
4759 {
4760 cx.read_window(self, |root_view, _cx| root_view.clone())
4761 }
4762
4763 /// Check if this window is 'active'.
4764 ///
4765 /// Will return `None` if the window is closed or currently
4766 /// borrowed.
4767 pub fn is_active(&self, cx: &mut AppContext) -> Option<bool> {
4768 cx.update_window(self.any_handle, |_, cx| cx.is_window_active())
4769 .ok()
4770 }
4771}
4772
4773impl<V> Copy for WindowHandle<V> {}
4774
4775impl<V> Clone for WindowHandle<V> {
4776 fn clone(&self) -> Self {
4777 *self
4778 }
4779}
4780
4781impl<V> PartialEq for WindowHandle<V> {
4782 fn eq(&self, other: &Self) -> bool {
4783 self.any_handle == other.any_handle
4784 }
4785}
4786
4787impl<V> Eq for WindowHandle<V> {}
4788
4789impl<V> Hash for WindowHandle<V> {
4790 fn hash<H: Hasher>(&self, state: &mut H) {
4791 self.any_handle.hash(state);
4792 }
4793}
4794
4795impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
4796 fn from(val: WindowHandle<V>) -> Self {
4797 val.any_handle
4798 }
4799}
4800
4801unsafe impl<V> Send for WindowHandle<V> {}
4802unsafe impl<V> Sync for WindowHandle<V> {}
4803
4804/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
4805#[derive(Copy, Clone, PartialEq, Eq, Hash)]
4806pub struct AnyWindowHandle {
4807 pub(crate) id: WindowId,
4808 state_type: TypeId,
4809}
4810
4811impl AnyWindowHandle {
4812 /// Get the ID of this window.
4813 pub fn window_id(&self) -> WindowId {
4814 self.id
4815 }
4816
4817 /// Attempt to convert this handle to a window handle with a specific root view type.
4818 /// If the types do not match, this will return `None`.
4819 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
4820 if TypeId::of::<T>() == self.state_type {
4821 Some(WindowHandle {
4822 any_handle: *self,
4823 state_type: PhantomData,
4824 })
4825 } else {
4826 None
4827 }
4828 }
4829
4830 /// Updates the state of the root view of this window.
4831 ///
4832 /// This will fail if the window has been closed.
4833 pub fn update<C, R>(
4834 self,
4835 cx: &mut C,
4836 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
4837 ) -> Result<R>
4838 where
4839 C: Context,
4840 {
4841 cx.update_window(self, update)
4842 }
4843
4844 /// Read the state of the root view of this window.
4845 ///
4846 /// This will fail if the window has been closed.
4847 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
4848 where
4849 C: Context,
4850 T: 'static,
4851 {
4852 let view = self
4853 .downcast::<T>()
4854 .context("the type of the window's root view has changed")?;
4855
4856 cx.read_window(&view, read)
4857 }
4858}
4859
4860/// An identifier for an [`Element`](crate::Element).
4861///
4862/// Can be constructed with a string, a number, or both, as well
4863/// as other internal representations.
4864#[derive(Clone, Debug, Eq, PartialEq, Hash)]
4865pub enum ElementId {
4866 /// The ID of a View element
4867 View(EntityId),
4868 /// An integer ID.
4869 Integer(usize),
4870 /// A string based ID.
4871 Name(SharedString),
4872 /// A UUID.
4873 Uuid(Uuid),
4874 /// An ID that's equated with a focus handle.
4875 FocusHandle(FocusId),
4876 /// A combination of a name and an integer.
4877 NamedInteger(SharedString, usize),
4878}
4879
4880impl Display for ElementId {
4881 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4882 match self {
4883 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
4884 ElementId::Integer(ix) => write!(f, "{}", ix)?,
4885 ElementId::Name(name) => write!(f, "{}", name)?,
4886 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
4887 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
4888 ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
4889 }
4890
4891 Ok(())
4892 }
4893}
4894
4895impl TryInto<SharedString> for ElementId {
4896 type Error = anyhow::Error;
4897
4898 fn try_into(self) -> anyhow::Result<SharedString> {
4899 if let ElementId::Name(name) = self {
4900 Ok(name)
4901 } else {
4902 Err(anyhow!("element id is not string"))
4903 }
4904 }
4905}
4906
4907impl From<usize> for ElementId {
4908 fn from(id: usize) -> Self {
4909 ElementId::Integer(id)
4910 }
4911}
4912
4913impl From<i32> for ElementId {
4914 fn from(id: i32) -> Self {
4915 Self::Integer(id as usize)
4916 }
4917}
4918
4919impl From<SharedString> for ElementId {
4920 fn from(name: SharedString) -> Self {
4921 ElementId::Name(name)
4922 }
4923}
4924
4925impl From<&'static str> for ElementId {
4926 fn from(name: &'static str) -> Self {
4927 ElementId::Name(name.into())
4928 }
4929}
4930
4931impl<'a> From<&'a FocusHandle> for ElementId {
4932 fn from(handle: &'a FocusHandle) -> Self {
4933 ElementId::FocusHandle(handle.id)
4934 }
4935}
4936
4937impl From<(&'static str, EntityId)> for ElementId {
4938 fn from((name, id): (&'static str, EntityId)) -> Self {
4939 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
4940 }
4941}
4942
4943impl From<(&'static str, usize)> for ElementId {
4944 fn from((name, id): (&'static str, usize)) -> Self {
4945 ElementId::NamedInteger(name.into(), id)
4946 }
4947}
4948
4949impl From<(SharedString, usize)> for ElementId {
4950 fn from((name, id): (SharedString, usize)) -> Self {
4951 ElementId::NamedInteger(name, id)
4952 }
4953}
4954
4955impl From<(&'static str, u64)> for ElementId {
4956 fn from((name, id): (&'static str, u64)) -> Self {
4957 ElementId::NamedInteger(name.into(), id as usize)
4958 }
4959}
4960
4961impl From<Uuid> for ElementId {
4962 fn from(value: Uuid) -> Self {
4963 Self::Uuid(value)
4964 }
4965}
4966
4967impl From<(&'static str, u32)> for ElementId {
4968 fn from((name, id): (&'static str, u32)) -> Self {
4969 ElementId::NamedInteger(name.into(), id as usize)
4970 }
4971}
4972
4973/// A rectangle to be rendered in the window at the given position and size.
4974/// Passed as an argument [`WindowContext::paint_quad`].
4975#[derive(Clone)]
4976pub struct PaintQuad {
4977 /// The bounds of the quad within the window.
4978 pub bounds: Bounds<Pixels>,
4979 /// The radii of the quad's corners.
4980 pub corner_radii: Corners<Pixels>,
4981 /// The background color of the quad.
4982 pub background: Background,
4983 /// The widths of the quad's borders.
4984 pub border_widths: Edges<Pixels>,
4985 /// The color of the quad's borders.
4986 pub border_color: Hsla,
4987}
4988
4989impl PaintQuad {
4990 /// Sets the corner radii of the quad.
4991 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
4992 PaintQuad {
4993 corner_radii: corner_radii.into(),
4994 ..self
4995 }
4996 }
4997
4998 /// Sets the border widths of the quad.
4999 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
5000 PaintQuad {
5001 border_widths: border_widths.into(),
5002 ..self
5003 }
5004 }
5005
5006 /// Sets the border color of the quad.
5007 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
5008 PaintQuad {
5009 border_color: border_color.into(),
5010 ..self
5011 }
5012 }
5013
5014 /// Sets the background color of the quad.
5015 pub fn background(self, background: impl Into<Background>) -> Self {
5016 PaintQuad {
5017 background: background.into(),
5018 ..self
5019 }
5020 }
5021}
5022
5023/// Creates a quad with the given parameters.
5024pub fn quad(
5025 bounds: Bounds<Pixels>,
5026 corner_radii: impl Into<Corners<Pixels>>,
5027 background: impl Into<Background>,
5028 border_widths: impl Into<Edges<Pixels>>,
5029 border_color: impl Into<Hsla>,
5030) -> PaintQuad {
5031 PaintQuad {
5032 bounds,
5033 corner_radii: corner_radii.into(),
5034 background: background.into(),
5035 border_widths: border_widths.into(),
5036 border_color: border_color.into(),
5037 }
5038}
5039
5040/// Creates a filled quad with the given bounds and background color.
5041pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
5042 PaintQuad {
5043 bounds: bounds.into(),
5044 corner_radii: (0.).into(),
5045 background: background.into(),
5046 border_widths: (0.).into(),
5047 border_color: transparent_black(),
5048 }
5049}
5050
5051/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
5052pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
5053 PaintQuad {
5054 bounds: bounds.into(),
5055 corner_radii: (0.).into(),
5056 background: transparent_black().into(),
5057 border_widths: (1.).into(),
5058 border_color: border_color.into(),
5059 }
5060}