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 mut shadow_bounds = bounds;
2285 shadow_bounds.origin += shadow.offset;
2286 shadow_bounds.dilate(shadow.spread_radius);
2287 self.window.next_frame.scene.insert_primitive(Shadow {
2288 order: 0,
2289 blur_radius: shadow.blur_radius.scale(scale_factor),
2290 bounds: shadow_bounds.scale(scale_factor),
2291 content_mask: content_mask.scale(scale_factor),
2292 corner_radii: corner_radii.scale(scale_factor),
2293 color: shadow.color.opacity(opacity),
2294 });
2295 }
2296 }
2297
2298 /// Paint one or more quads into the scene for the next frame at the current stacking context.
2299 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2300 /// see [`fill`](crate::fill), [`outline`](crate::outline), and [`quad`](crate::quad) to construct this type.
2301 ///
2302 /// This method should only be called as part of the paint phase of element drawing.
2303 pub fn paint_quad(&mut self, quad: PaintQuad) {
2304 debug_assert_eq!(
2305 self.window.draw_phase,
2306 DrawPhase::Paint,
2307 "this method can only be called during paint"
2308 );
2309
2310 let scale_factor = self.scale_factor();
2311 let content_mask = self.content_mask();
2312 let opacity = self.element_opacity();
2313 self.window.next_frame.scene.insert_primitive(Quad {
2314 order: 0,
2315 pad: 0,
2316 bounds: quad.bounds.scale(scale_factor),
2317 content_mask: content_mask.scale(scale_factor),
2318 background: quad.background.opacity(opacity),
2319 border_color: quad.border_color.opacity(opacity),
2320 corner_radii: quad.corner_radii.scale(scale_factor),
2321 border_widths: quad.border_widths.scale(scale_factor),
2322 });
2323 }
2324
2325 /// Paint the given `Path` into the scene for the next frame at the current z-index.
2326 ///
2327 /// This method should only be called as part of the paint phase of element drawing.
2328 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
2329 debug_assert_eq!(
2330 self.window.draw_phase,
2331 DrawPhase::Paint,
2332 "this method can only be called during paint"
2333 );
2334
2335 let scale_factor = self.scale_factor();
2336 let content_mask = self.content_mask();
2337 let opacity = self.element_opacity();
2338 path.content_mask = content_mask;
2339 let color: Background = color.into();
2340 path.color = color.opacity(opacity);
2341 self.window
2342 .next_frame
2343 .scene
2344 .insert_primitive(path.scale(scale_factor));
2345 }
2346
2347 /// Paint an underline into the scene for the next frame at the current z-index.
2348 ///
2349 /// This method should only be called as part of the paint phase of element drawing.
2350 pub fn paint_underline(
2351 &mut self,
2352 origin: Point<Pixels>,
2353 width: Pixels,
2354 style: &UnderlineStyle,
2355 ) {
2356 debug_assert_eq!(
2357 self.window.draw_phase,
2358 DrawPhase::Paint,
2359 "this method can only be called during paint"
2360 );
2361
2362 let scale_factor = self.scale_factor();
2363 let height = if style.wavy {
2364 style.thickness * 3.
2365 } else {
2366 style.thickness
2367 };
2368 let bounds = Bounds {
2369 origin,
2370 size: size(width, height),
2371 };
2372 let content_mask = self.content_mask();
2373 let element_opacity = self.element_opacity();
2374
2375 self.window.next_frame.scene.insert_primitive(Underline {
2376 order: 0,
2377 pad: 0,
2378 bounds: bounds.scale(scale_factor),
2379 content_mask: content_mask.scale(scale_factor),
2380 color: style.color.unwrap_or_default().opacity(element_opacity),
2381 thickness: style.thickness.scale(scale_factor),
2382 wavy: style.wavy,
2383 });
2384 }
2385
2386 /// Paint a strikethrough into the scene for the next frame at the current z-index.
2387 ///
2388 /// This method should only be called as part of the paint phase of element drawing.
2389 pub fn paint_strikethrough(
2390 &mut self,
2391 origin: Point<Pixels>,
2392 width: Pixels,
2393 style: &StrikethroughStyle,
2394 ) {
2395 debug_assert_eq!(
2396 self.window.draw_phase,
2397 DrawPhase::Paint,
2398 "this method can only be called during paint"
2399 );
2400
2401 let scale_factor = self.scale_factor();
2402 let height = style.thickness;
2403 let bounds = Bounds {
2404 origin,
2405 size: size(width, height),
2406 };
2407 let content_mask = self.content_mask();
2408 let opacity = self.element_opacity();
2409
2410 self.window.next_frame.scene.insert_primitive(Underline {
2411 order: 0,
2412 pad: 0,
2413 bounds: bounds.scale(scale_factor),
2414 content_mask: content_mask.scale(scale_factor),
2415 thickness: style.thickness.scale(scale_factor),
2416 color: style.color.unwrap_or_default().opacity(opacity),
2417 wavy: false,
2418 });
2419 }
2420
2421 /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
2422 ///
2423 /// The y component of the origin is the baseline of the glyph.
2424 /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2425 /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2426 /// This method is only useful if you need to paint a single glyph that has already been shaped.
2427 ///
2428 /// This method should only be called as part of the paint phase of element drawing.
2429 pub fn paint_glyph(
2430 &mut self,
2431 origin: Point<Pixels>,
2432 font_id: FontId,
2433 glyph_id: GlyphId,
2434 font_size: Pixels,
2435 color: Hsla,
2436 ) -> Result<()> {
2437 debug_assert_eq!(
2438 self.window.draw_phase,
2439 DrawPhase::Paint,
2440 "this method can only be called during paint"
2441 );
2442
2443 let element_opacity = self.element_opacity();
2444 let scale_factor = self.scale_factor();
2445 let glyph_origin = origin.scale(scale_factor);
2446 let subpixel_variant = Point {
2447 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2448 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2449 };
2450 let params = RenderGlyphParams {
2451 font_id,
2452 glyph_id,
2453 font_size,
2454 subpixel_variant,
2455 scale_factor,
2456 is_emoji: false,
2457 };
2458
2459 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
2460 if !raster_bounds.is_zero() {
2461 let tile = self
2462 .window
2463 .sprite_atlas
2464 .get_or_insert_with(¶ms.clone().into(), &mut || {
2465 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
2466 Ok(Some((size, Cow::Owned(bytes))))
2467 })?
2468 .expect("Callback above only errors or returns Some");
2469 let bounds = Bounds {
2470 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2471 size: tile.bounds.size.map(Into::into),
2472 };
2473 let content_mask = self.content_mask().scale(scale_factor);
2474 self.window
2475 .next_frame
2476 .scene
2477 .insert_primitive(MonochromeSprite {
2478 order: 0,
2479 pad: 0,
2480 bounds,
2481 content_mask,
2482 color: color.opacity(element_opacity),
2483 tile,
2484 transformation: TransformationMatrix::unit(),
2485 });
2486 }
2487 Ok(())
2488 }
2489
2490 /// Paints an emoji glyph into the scene for the next frame at the current z-index.
2491 ///
2492 /// The y component of the origin is the baseline of the glyph.
2493 /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2494 /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2495 /// This method is only useful if you need to paint a single emoji that has already been shaped.
2496 ///
2497 /// This method should only be called as part of the paint phase of element drawing.
2498 pub fn paint_emoji(
2499 &mut self,
2500 origin: Point<Pixels>,
2501 font_id: FontId,
2502 glyph_id: GlyphId,
2503 font_size: Pixels,
2504 ) -> Result<()> {
2505 debug_assert_eq!(
2506 self.window.draw_phase,
2507 DrawPhase::Paint,
2508 "this method can only be called during paint"
2509 );
2510
2511 let scale_factor = self.scale_factor();
2512 let glyph_origin = origin.scale(scale_factor);
2513 let params = RenderGlyphParams {
2514 font_id,
2515 glyph_id,
2516 font_size,
2517 // We don't render emojis with subpixel variants.
2518 subpixel_variant: Default::default(),
2519 scale_factor,
2520 is_emoji: true,
2521 };
2522
2523 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
2524 if !raster_bounds.is_zero() {
2525 let tile = self
2526 .window
2527 .sprite_atlas
2528 .get_or_insert_with(¶ms.clone().into(), &mut || {
2529 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
2530 Ok(Some((size, Cow::Owned(bytes))))
2531 })?
2532 .expect("Callback above only errors or returns Some");
2533
2534 let bounds = Bounds {
2535 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2536 size: tile.bounds.size.map(Into::into),
2537 };
2538 let content_mask = self.content_mask().scale(scale_factor);
2539 let opacity = self.element_opacity();
2540
2541 self.window
2542 .next_frame
2543 .scene
2544 .insert_primitive(PolychromeSprite {
2545 order: 0,
2546 pad: 0,
2547 grayscale: false,
2548 bounds,
2549 corner_radii: Default::default(),
2550 content_mask,
2551 tile,
2552 opacity,
2553 });
2554 }
2555 Ok(())
2556 }
2557
2558 /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
2559 ///
2560 /// This method should only be called as part of the paint phase of element drawing.
2561 pub fn paint_svg(
2562 &mut self,
2563 bounds: Bounds<Pixels>,
2564 path: SharedString,
2565 transformation: TransformationMatrix,
2566 color: Hsla,
2567 ) -> Result<()> {
2568 debug_assert_eq!(
2569 self.window.draw_phase,
2570 DrawPhase::Paint,
2571 "this method can only be called during paint"
2572 );
2573
2574 let element_opacity = self.element_opacity();
2575 let scale_factor = self.scale_factor();
2576 let bounds = bounds.scale(scale_factor);
2577 // Render the SVG at twice the size to get a higher quality result.
2578 let params = RenderSvgParams {
2579 path,
2580 size: bounds
2581 .size
2582 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
2583 };
2584
2585 let Some(tile) =
2586 self.window
2587 .sprite_atlas
2588 .get_or_insert_with(¶ms.clone().into(), &mut || {
2589 let Some(bytes) = self.svg_renderer.render(¶ms)? else {
2590 return Ok(None);
2591 };
2592 Ok(Some((params.size, Cow::Owned(bytes))))
2593 })?
2594 else {
2595 return Ok(());
2596 };
2597 let content_mask = self.content_mask().scale(scale_factor);
2598
2599 self.window
2600 .next_frame
2601 .scene
2602 .insert_primitive(MonochromeSprite {
2603 order: 0,
2604 pad: 0,
2605 bounds: bounds
2606 .map_origin(|origin| origin.floor())
2607 .map_size(|size| size.ceil()),
2608 content_mask,
2609 color: color.opacity(element_opacity),
2610 tile,
2611 transformation,
2612 });
2613
2614 Ok(())
2615 }
2616
2617 /// Paint an image into the scene for the next frame at the current z-index.
2618 /// This method will panic if the frame_index is not valid
2619 ///
2620 /// This method should only be called as part of the paint phase of element drawing.
2621 pub fn paint_image(
2622 &mut self,
2623 bounds: Bounds<Pixels>,
2624 corner_radii: Corners<Pixels>,
2625 data: Arc<RenderImage>,
2626 frame_index: usize,
2627 grayscale: bool,
2628 ) -> Result<()> {
2629 debug_assert_eq!(
2630 self.window.draw_phase,
2631 DrawPhase::Paint,
2632 "this method can only be called during paint"
2633 );
2634
2635 let scale_factor = self.scale_factor();
2636 let bounds = bounds.scale(scale_factor);
2637 let params = RenderImageParams {
2638 image_id: data.id,
2639 frame_index,
2640 };
2641
2642 let tile = self
2643 .window
2644 .sprite_atlas
2645 .get_or_insert_with(¶ms.clone().into(), &mut || {
2646 Ok(Some((
2647 data.size(frame_index),
2648 Cow::Borrowed(
2649 data.as_bytes(frame_index)
2650 .expect("It's the caller's job to pass a valid frame index"),
2651 ),
2652 )))
2653 })?
2654 .expect("Callback above only returns Some");
2655 let content_mask = self.content_mask().scale(scale_factor);
2656 let corner_radii = corner_radii.scale(scale_factor);
2657 let opacity = self.element_opacity();
2658
2659 self.window
2660 .next_frame
2661 .scene
2662 .insert_primitive(PolychromeSprite {
2663 order: 0,
2664 pad: 0,
2665 grayscale,
2666 bounds,
2667 content_mask,
2668 corner_radii,
2669 tile,
2670 opacity,
2671 });
2672 Ok(())
2673 }
2674
2675 /// Paint a surface into the scene for the next frame at the current z-index.
2676 ///
2677 /// This method should only be called as part of the paint phase of element drawing.
2678 #[cfg(target_os = "macos")]
2679 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
2680 use crate::PaintSurface;
2681
2682 debug_assert_eq!(
2683 self.window.draw_phase,
2684 DrawPhase::Paint,
2685 "this method can only be called during paint"
2686 );
2687
2688 let scale_factor = self.scale_factor();
2689 let bounds = bounds.scale(scale_factor);
2690 let content_mask = self.content_mask().scale(scale_factor);
2691 self.window.next_frame.scene.insert_primitive(PaintSurface {
2692 order: 0,
2693 bounds,
2694 content_mask,
2695 image_buffer,
2696 });
2697 }
2698
2699 /// Removes an image from the sprite atlas.
2700 pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
2701 for frame_index in 0..data.frame_count() {
2702 let params = RenderImageParams {
2703 image_id: data.id,
2704 frame_index,
2705 };
2706
2707 self.window.sprite_atlas.remove(¶ms.clone().into());
2708 }
2709
2710 Ok(())
2711 }
2712
2713 #[must_use]
2714 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
2715 /// layout is being requested, along with the layout ids of any children. This method is called during
2716 /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
2717 ///
2718 /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2719 pub fn request_layout(
2720 &mut self,
2721 style: Style,
2722 children: impl IntoIterator<Item = LayoutId>,
2723 ) -> LayoutId {
2724 debug_assert_eq!(
2725 self.window.draw_phase,
2726 DrawPhase::Prepaint,
2727 "this method can only be called during request_layout, or prepaint"
2728 );
2729
2730 self.app.layout_id_buffer.clear();
2731 self.app.layout_id_buffer.extend(children);
2732 let rem_size = self.rem_size();
2733
2734 self.window.layout_engine.as_mut().unwrap().request_layout(
2735 style,
2736 rem_size,
2737 &self.app.layout_id_buffer,
2738 )
2739 }
2740
2741 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
2742 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
2743 /// determine the element's size. One place this is used internally is when measuring text.
2744 ///
2745 /// The given closure is invoked at layout time with the known dimensions and available space and
2746 /// returns a `Size`.
2747 ///
2748 /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2749 pub fn request_measured_layout<
2750 F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut WindowContext) -> Size<Pixels>
2751 + 'static,
2752 >(
2753 &mut self,
2754 style: Style,
2755 measure: F,
2756 ) -> LayoutId {
2757 debug_assert_eq!(
2758 self.window.draw_phase,
2759 DrawPhase::Prepaint,
2760 "this method can only be called during request_layout, or prepaint"
2761 );
2762
2763 let rem_size = self.rem_size();
2764 self.window
2765 .layout_engine
2766 .as_mut()
2767 .unwrap()
2768 .request_measured_layout(style, rem_size, measure)
2769 }
2770
2771 /// Compute the layout for the given id within the given available space.
2772 /// This method is called for its side effect, typically by the framework prior to painting.
2773 /// After calling it, you can request the bounds of the given layout node id or any descendant.
2774 ///
2775 /// This method should only be called as part of the prepaint phase of element drawing.
2776 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
2777 debug_assert_eq!(
2778 self.window.draw_phase,
2779 DrawPhase::Prepaint,
2780 "this method can only be called during request_layout, or prepaint"
2781 );
2782
2783 let mut layout_engine = self.window.layout_engine.take().unwrap();
2784 layout_engine.compute_layout(layout_id, available_space, self);
2785 self.window.layout_engine = Some(layout_engine);
2786 }
2787
2788 /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
2789 /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
2790 ///
2791 /// This method should only be called as part of element drawing.
2792 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
2793 debug_assert_eq!(
2794 self.window.draw_phase,
2795 DrawPhase::Prepaint,
2796 "this method can only be called during request_layout, prepaint, or paint"
2797 );
2798
2799 let mut bounds = self
2800 .window
2801 .layout_engine
2802 .as_mut()
2803 .unwrap()
2804 .layout_bounds(layout_id)
2805 .map(Into::into);
2806 bounds.origin += self.element_offset();
2807 bounds
2808 }
2809
2810 /// This method should be called during `prepaint`. You can use
2811 /// the returned [Hitbox] during `paint` or in an event handler
2812 /// to determine whether the inserted hitbox was the topmost.
2813 ///
2814 /// This method should only be called as part of the prepaint phase of element drawing.
2815 pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, opaque: bool) -> Hitbox {
2816 debug_assert_eq!(
2817 self.window.draw_phase,
2818 DrawPhase::Prepaint,
2819 "this method can only be called during prepaint"
2820 );
2821
2822 let content_mask = self.content_mask();
2823 let window = &mut self.window;
2824 let id = window.next_hitbox_id;
2825 window.next_hitbox_id.0 += 1;
2826 let hitbox = Hitbox {
2827 id,
2828 bounds,
2829 content_mask,
2830 opaque,
2831 };
2832 window.next_frame.hitboxes.push(hitbox.clone());
2833 hitbox
2834 }
2835
2836 /// Sets the key context for the current element. This context will be used to translate
2837 /// keybindings into actions.
2838 ///
2839 /// This method should only be called as part of the paint phase of element drawing.
2840 pub fn set_key_context(&mut self, context: KeyContext) {
2841 debug_assert_eq!(
2842 self.window.draw_phase,
2843 DrawPhase::Paint,
2844 "this method can only be called during paint"
2845 );
2846 self.window
2847 .next_frame
2848 .dispatch_tree
2849 .set_key_context(context);
2850 }
2851
2852 /// Sets the focus handle for the current element. This handle will be used to manage focus state
2853 /// and keyboard event dispatch for the element.
2854 ///
2855 /// This method should only be called as part of the prepaint phase of element drawing.
2856 pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle) {
2857 debug_assert_eq!(
2858 self.window.draw_phase,
2859 DrawPhase::Prepaint,
2860 "this method can only be called during prepaint"
2861 );
2862 if focus_handle.is_focused(self) {
2863 self.window.next_frame.focus = Some(focus_handle.id);
2864 }
2865 self.window
2866 .next_frame
2867 .dispatch_tree
2868 .set_focus_id(focus_handle.id);
2869 }
2870
2871 /// Sets the view id for the current element, which will be used to manage view caching.
2872 ///
2873 /// This method should only be called as part of element prepaint. We plan on removing this
2874 /// method eventually when we solve some issues that require us to construct editor elements
2875 /// directly instead of always using editors via views.
2876 pub fn set_view_id(&mut self, view_id: EntityId) {
2877 debug_assert_eq!(
2878 self.window.draw_phase,
2879 DrawPhase::Prepaint,
2880 "this method can only be called during prepaint"
2881 );
2882 self.window.next_frame.dispatch_tree.set_view_id(view_id);
2883 }
2884
2885 /// Get the last view id for the current element
2886 pub fn parent_view_id(&self) -> Option<EntityId> {
2887 self.window.next_frame.dispatch_tree.parent_view_id()
2888 }
2889
2890 /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
2891 /// platform to receive textual input with proper integration with concerns such
2892 /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
2893 /// rendered.
2894 ///
2895 /// This method should only be called as part of the paint phase of element drawing.
2896 ///
2897 /// [element_input_handler]: crate::ElementInputHandler
2898 pub fn handle_input(&mut self, focus_handle: &FocusHandle, input_handler: impl InputHandler) {
2899 debug_assert_eq!(
2900 self.window.draw_phase,
2901 DrawPhase::Paint,
2902 "this method can only be called during paint"
2903 );
2904
2905 if focus_handle.is_focused(self) {
2906 let cx = self.to_async();
2907 self.window
2908 .next_frame
2909 .input_handlers
2910 .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
2911 }
2912 }
2913
2914 /// Register a mouse event listener on the window for the next frame. The type of event
2915 /// is determined by the first parameter of the given listener. When the next frame is rendered
2916 /// the listener will be cleared.
2917 ///
2918 /// This method should only be called as part of the paint phase of element drawing.
2919 pub fn on_mouse_event<Event: MouseEvent>(
2920 &mut self,
2921 mut handler: impl FnMut(&Event, DispatchPhase, &mut WindowContext) + 'static,
2922 ) {
2923 debug_assert_eq!(
2924 self.window.draw_phase,
2925 DrawPhase::Paint,
2926 "this method can only be called during paint"
2927 );
2928
2929 self.window.next_frame.mouse_listeners.push(Some(Box::new(
2930 move |event: &dyn Any, phase: DispatchPhase, cx: &mut WindowContext<'_>| {
2931 if let Some(event) = event.downcast_ref() {
2932 handler(event, phase, cx)
2933 }
2934 },
2935 )));
2936 }
2937
2938 /// Register a key event listener on the window for the next frame. The type of event
2939 /// is determined by the first parameter of the given listener. When the next frame is rendered
2940 /// the listener will be cleared.
2941 ///
2942 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2943 /// a specific need to register a global listener.
2944 ///
2945 /// This method should only be called as part of the paint phase of element drawing.
2946 pub fn on_key_event<Event: KeyEvent>(
2947 &mut self,
2948 listener: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
2949 ) {
2950 debug_assert_eq!(
2951 self.window.draw_phase,
2952 DrawPhase::Paint,
2953 "this method can only be called during paint"
2954 );
2955
2956 self.window.next_frame.dispatch_tree.on_key_event(Rc::new(
2957 move |event: &dyn Any, phase, cx: &mut WindowContext<'_>| {
2958 if let Some(event) = event.downcast_ref::<Event>() {
2959 listener(event, phase, cx)
2960 }
2961 },
2962 ));
2963 }
2964
2965 /// Register a modifiers changed event listener on the window for the next frame.
2966 ///
2967 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2968 /// a specific need to register a global listener.
2969 ///
2970 /// This method should only be called as part of the paint phase of element drawing.
2971 pub fn on_modifiers_changed(
2972 &mut self,
2973 listener: impl Fn(&ModifiersChangedEvent, &mut WindowContext) + 'static,
2974 ) {
2975 debug_assert_eq!(
2976 self.window.draw_phase,
2977 DrawPhase::Paint,
2978 "this method can only be called during paint"
2979 );
2980
2981 self.window
2982 .next_frame
2983 .dispatch_tree
2984 .on_modifiers_changed(Rc::new(
2985 move |event: &ModifiersChangedEvent, cx: &mut WindowContext<'_>| {
2986 listener(event, cx)
2987 },
2988 ));
2989 }
2990
2991 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2992 /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
2993 /// Returns a subscription and persists until the subscription is dropped.
2994 pub fn on_focus_in(
2995 &mut self,
2996 handle: &FocusHandle,
2997 mut listener: impl FnMut(&mut WindowContext) + 'static,
2998 ) -> Subscription {
2999 let focus_id = handle.id;
3000 let (subscription, activate) =
3001 self.window.new_focus_listener(Box::new(move |event, cx| {
3002 if event.is_focus_in(focus_id) {
3003 listener(cx);
3004 }
3005 true
3006 }));
3007 self.app.defer(move |_| activate());
3008 subscription
3009 }
3010
3011 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3012 /// Returns a subscription and persists until the subscription is dropped.
3013 pub fn on_focus_out(
3014 &mut self,
3015 handle: &FocusHandle,
3016 mut listener: impl FnMut(FocusOutEvent, &mut WindowContext) + 'static,
3017 ) -> Subscription {
3018 let focus_id = handle.id;
3019 let (subscription, activate) =
3020 self.window.new_focus_listener(Box::new(move |event, cx| {
3021 if let Some(blurred_id) = event.previous_focus_path.last().copied() {
3022 if event.is_focus_out(focus_id) {
3023 let event = FocusOutEvent {
3024 blurred: WeakFocusHandle {
3025 id: blurred_id,
3026 handles: Arc::downgrade(&cx.window.focus_handles),
3027 },
3028 };
3029 listener(event, cx)
3030 }
3031 }
3032 true
3033 }));
3034 self.app.defer(move |_| activate());
3035 subscription
3036 }
3037
3038 fn reset_cursor_style(&self) {
3039 // Set the cursor only if we're the active window.
3040 if self.is_window_hovered() {
3041 let style = self
3042 .window
3043 .rendered_frame
3044 .cursor_styles
3045 .iter()
3046 .rev()
3047 .find(|request| request.hitbox_id.is_hovered(self))
3048 .map(|request| request.style)
3049 .unwrap_or(CursorStyle::Arrow);
3050 self.platform.set_cursor_style(style);
3051 }
3052 }
3053
3054 /// Dispatch a given keystroke as though the user had typed it.
3055 /// You can create a keystroke with Keystroke::parse("").
3056 pub fn dispatch_keystroke(&mut self, keystroke: Keystroke) -> bool {
3057 let keystroke = keystroke.with_simulated_ime();
3058 let result = self.dispatch_event(PlatformInput::KeyDown(KeyDownEvent {
3059 keystroke: keystroke.clone(),
3060 is_held: false,
3061 }));
3062 if !result.propagate {
3063 return true;
3064 }
3065
3066 if let Some(input) = keystroke.key_char {
3067 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
3068 input_handler.dispatch_input(&input, self);
3069 self.window.platform_window.set_input_handler(input_handler);
3070 return true;
3071 }
3072 }
3073
3074 false
3075 }
3076
3077 /// Represent this action as a key binding string, to display in the UI.
3078 pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3079 self.bindings_for_action(action)
3080 .into_iter()
3081 .next()
3082 .map(|binding| {
3083 binding
3084 .keystrokes()
3085 .iter()
3086 .map(ToString::to_string)
3087 .collect::<Vec<_>>()
3088 .join(" ")
3089 })
3090 .unwrap_or_else(|| action.name().to_string())
3091 }
3092
3093 /// Dispatch a mouse or keyboard event on the window.
3094 #[profiling::function]
3095 pub fn dispatch_event(&mut self, event: PlatformInput) -> DispatchEventResult {
3096 self.window.last_input_timestamp.set(Instant::now());
3097 // Handlers may set this to false by calling `stop_propagation`.
3098 self.app.propagate_event = true;
3099 // Handlers may set this to true by calling `prevent_default`.
3100 self.window.default_prevented = false;
3101
3102 let event = match event {
3103 // Track the mouse position with our own state, since accessing the platform
3104 // API for the mouse position can only occur on the main thread.
3105 PlatformInput::MouseMove(mouse_move) => {
3106 self.window.mouse_position = mouse_move.position;
3107 self.window.modifiers = mouse_move.modifiers;
3108 PlatformInput::MouseMove(mouse_move)
3109 }
3110 PlatformInput::MouseDown(mouse_down) => {
3111 self.window.mouse_position = mouse_down.position;
3112 self.window.modifiers = mouse_down.modifiers;
3113 PlatformInput::MouseDown(mouse_down)
3114 }
3115 PlatformInput::MouseUp(mouse_up) => {
3116 self.window.mouse_position = mouse_up.position;
3117 self.window.modifiers = mouse_up.modifiers;
3118 PlatformInput::MouseUp(mouse_up)
3119 }
3120 PlatformInput::MouseExited(mouse_exited) => {
3121 self.window.modifiers = mouse_exited.modifiers;
3122 PlatformInput::MouseExited(mouse_exited)
3123 }
3124 PlatformInput::ModifiersChanged(modifiers_changed) => {
3125 self.window.modifiers = modifiers_changed.modifiers;
3126 PlatformInput::ModifiersChanged(modifiers_changed)
3127 }
3128 PlatformInput::ScrollWheel(scroll_wheel) => {
3129 self.window.mouse_position = scroll_wheel.position;
3130 self.window.modifiers = scroll_wheel.modifiers;
3131 PlatformInput::ScrollWheel(scroll_wheel)
3132 }
3133 // Translate dragging and dropping of external files from the operating system
3134 // to internal drag and drop events.
3135 PlatformInput::FileDrop(file_drop) => match file_drop {
3136 FileDropEvent::Entered { position, paths } => {
3137 self.window.mouse_position = position;
3138 if self.active_drag.is_none() {
3139 self.active_drag = Some(AnyDrag {
3140 value: Arc::new(paths.clone()),
3141 view: self.new_view(|_| paths).into(),
3142 cursor_offset: position,
3143 });
3144 }
3145 PlatformInput::MouseMove(MouseMoveEvent {
3146 position,
3147 pressed_button: Some(MouseButton::Left),
3148 modifiers: Modifiers::default(),
3149 })
3150 }
3151 FileDropEvent::Pending { position } => {
3152 self.window.mouse_position = position;
3153 PlatformInput::MouseMove(MouseMoveEvent {
3154 position,
3155 pressed_button: Some(MouseButton::Left),
3156 modifiers: Modifiers::default(),
3157 })
3158 }
3159 FileDropEvent::Submit { position } => {
3160 self.activate(true);
3161 self.window.mouse_position = position;
3162 PlatformInput::MouseUp(MouseUpEvent {
3163 button: MouseButton::Left,
3164 position,
3165 modifiers: Modifiers::default(),
3166 click_count: 1,
3167 })
3168 }
3169 FileDropEvent::Exited => {
3170 self.active_drag.take();
3171 PlatformInput::FileDrop(FileDropEvent::Exited)
3172 }
3173 },
3174 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3175 };
3176
3177 if let Some(any_mouse_event) = event.mouse_event() {
3178 self.dispatch_mouse_event(any_mouse_event);
3179 } else if let Some(any_key_event) = event.keyboard_event() {
3180 self.dispatch_key_event(any_key_event);
3181 }
3182
3183 DispatchEventResult {
3184 propagate: self.app.propagate_event,
3185 default_prevented: self.window.default_prevented,
3186 }
3187 }
3188
3189 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
3190 let hit_test = self.window.rendered_frame.hit_test(self.mouse_position());
3191 if hit_test != self.window.mouse_hit_test {
3192 self.window.mouse_hit_test = hit_test;
3193 self.reset_cursor_style();
3194 }
3195
3196 let mut mouse_listeners = mem::take(&mut self.window.rendered_frame.mouse_listeners);
3197
3198 // Capture phase, events bubble from back to front. Handlers for this phase are used for
3199 // special purposes, such as detecting events outside of a given Bounds.
3200 for listener in &mut mouse_listeners {
3201 let listener = listener.as_mut().unwrap();
3202 listener(event, DispatchPhase::Capture, self);
3203 if !self.app.propagate_event {
3204 break;
3205 }
3206 }
3207
3208 // Bubble phase, where most normal handlers do their work.
3209 if self.app.propagate_event {
3210 for listener in mouse_listeners.iter_mut().rev() {
3211 let listener = listener.as_mut().unwrap();
3212 listener(event, DispatchPhase::Bubble, self);
3213 if !self.app.propagate_event {
3214 break;
3215 }
3216 }
3217 }
3218
3219 self.window.rendered_frame.mouse_listeners = mouse_listeners;
3220
3221 if self.has_active_drag() {
3222 if event.is::<MouseMoveEvent>() {
3223 // If this was a mouse move event, redraw the window so that the
3224 // active drag can follow the mouse cursor.
3225 self.refresh();
3226 } else if event.is::<MouseUpEvent>() {
3227 // If this was a mouse up event, cancel the active drag and redraw
3228 // the window.
3229 self.active_drag = None;
3230 self.refresh();
3231 }
3232 }
3233 }
3234
3235 fn dispatch_key_event(&mut self, event: &dyn Any) {
3236 if self.window.dirty.get() {
3237 self.draw();
3238 }
3239
3240 let node_id = self
3241 .window
3242 .focus
3243 .and_then(|focus_id| {
3244 self.window
3245 .rendered_frame
3246 .dispatch_tree
3247 .focusable_node_id(focus_id)
3248 })
3249 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3250
3251 let dispatch_path = self
3252 .window
3253 .rendered_frame
3254 .dispatch_tree
3255 .dispatch_path(node_id);
3256
3257 let mut keystroke: Option<Keystroke> = None;
3258
3259 if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3260 if event.modifiers.number_of_modifiers() == 0
3261 && self.window.pending_modifier.modifiers.number_of_modifiers() == 1
3262 && !self.window.pending_modifier.saw_keystroke
3263 {
3264 let key = match self.window.pending_modifier.modifiers {
3265 modifiers if modifiers.shift => Some("shift"),
3266 modifiers if modifiers.control => Some("control"),
3267 modifiers if modifiers.alt => Some("alt"),
3268 modifiers if modifiers.platform => Some("platform"),
3269 modifiers if modifiers.function => Some("function"),
3270 _ => None,
3271 };
3272 if let Some(key) = key {
3273 keystroke = Some(Keystroke {
3274 key: key.to_string(),
3275 key_char: None,
3276 modifiers: Modifiers::default(),
3277 });
3278 }
3279 }
3280
3281 if self.window.pending_modifier.modifiers.number_of_modifiers() == 0
3282 && event.modifiers.number_of_modifiers() == 1
3283 {
3284 self.window.pending_modifier.saw_keystroke = false
3285 }
3286 self.window.pending_modifier.modifiers = event.modifiers
3287 } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3288 self.window.pending_modifier.saw_keystroke = true;
3289 keystroke = Some(key_down_event.keystroke.clone());
3290 }
3291
3292 let Some(keystroke) = keystroke else {
3293 self.finish_dispatch_key_event(event, dispatch_path);
3294 return;
3295 };
3296
3297 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
3298 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus {
3299 currently_pending = PendingInput::default();
3300 }
3301
3302 let match_result = self.window.rendered_frame.dispatch_tree.dispatch_key(
3303 currently_pending.keystrokes,
3304 keystroke,
3305 &dispatch_path,
3306 );
3307 if !match_result.to_replay.is_empty() {
3308 self.replay_pending_input(match_result.to_replay)
3309 }
3310
3311 if !match_result.pending.is_empty() {
3312 currently_pending.keystrokes = match_result.pending;
3313 currently_pending.focus = self.window.focus;
3314 currently_pending.timer = Some(self.spawn(|mut cx| async move {
3315 cx.background_executor.timer(Duration::from_secs(1)).await;
3316 cx.update(move |cx| {
3317 let Some(currently_pending) = cx
3318 .window
3319 .pending_input
3320 .take()
3321 .filter(|pending| pending.focus == cx.window.focus)
3322 else {
3323 return;
3324 };
3325
3326 let dispatch_path = cx
3327 .window
3328 .rendered_frame
3329 .dispatch_tree
3330 .dispatch_path(node_id);
3331
3332 let to_replay = cx
3333 .window
3334 .rendered_frame
3335 .dispatch_tree
3336 .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
3337
3338 cx.replay_pending_input(to_replay)
3339 })
3340 .log_err();
3341 }));
3342 self.window.pending_input = Some(currently_pending);
3343 self.pending_input_changed();
3344 self.propagate_event = false;
3345 return;
3346 }
3347
3348 self.propagate_event = true;
3349 for binding in match_result.bindings {
3350 self.dispatch_action_on_node(node_id, binding.action.as_ref());
3351 if !self.propagate_event {
3352 self.dispatch_keystroke_observers(event, Some(binding.action));
3353 self.pending_input_changed();
3354 return;
3355 }
3356 }
3357
3358 self.finish_dispatch_key_event(event, dispatch_path);
3359 self.pending_input_changed();
3360 }
3361
3362 fn finish_dispatch_key_event(
3363 &mut self,
3364 event: &dyn Any,
3365 dispatch_path: SmallVec<[DispatchNodeId; 32]>,
3366 ) {
3367 self.dispatch_key_down_up_event(event, &dispatch_path);
3368 if !self.propagate_event {
3369 return;
3370 }
3371
3372 self.dispatch_modifiers_changed_event(event, &dispatch_path);
3373 if !self.propagate_event {
3374 return;
3375 }
3376
3377 self.dispatch_keystroke_observers(event, None);
3378 }
3379
3380 fn pending_input_changed(&mut self) {
3381 self.window
3382 .pending_input_observers
3383 .clone()
3384 .retain(&(), |callback| callback(self));
3385 }
3386
3387 fn dispatch_key_down_up_event(
3388 &mut self,
3389 event: &dyn Any,
3390 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3391 ) {
3392 // Capture phase
3393 for node_id in dispatch_path {
3394 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3395
3396 for key_listener in node.key_listeners.clone() {
3397 key_listener(event, DispatchPhase::Capture, self);
3398 if !self.propagate_event {
3399 return;
3400 }
3401 }
3402 }
3403
3404 // Bubble phase
3405 for node_id in dispatch_path.iter().rev() {
3406 // Handle low level key events
3407 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3408 for key_listener in node.key_listeners.clone() {
3409 key_listener(event, DispatchPhase::Bubble, self);
3410 if !self.propagate_event {
3411 return;
3412 }
3413 }
3414 }
3415 }
3416
3417 fn dispatch_modifiers_changed_event(
3418 &mut self,
3419 event: &dyn Any,
3420 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3421 ) {
3422 let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
3423 return;
3424 };
3425 for node_id in dispatch_path.iter().rev() {
3426 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3427 for listener in node.modifiers_changed_listeners.clone() {
3428 listener(event, self);
3429 if !self.propagate_event {
3430 return;
3431 }
3432 }
3433 }
3434 }
3435
3436 /// Determine whether a potential multi-stroke key binding is in progress on this window.
3437 pub fn has_pending_keystrokes(&self) -> bool {
3438 self.window.pending_input.is_some()
3439 }
3440
3441 pub(crate) fn clear_pending_keystrokes(&mut self) {
3442 self.window.pending_input.take();
3443 }
3444
3445 /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
3446 pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
3447 self.window
3448 .pending_input
3449 .as_ref()
3450 .map(|pending_input| pending_input.keystrokes.as_slice())
3451 }
3452
3453 fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>) {
3454 let node_id = self
3455 .window
3456 .focus
3457 .and_then(|focus_id| {
3458 self.window
3459 .rendered_frame
3460 .dispatch_tree
3461 .focusable_node_id(focus_id)
3462 })
3463 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3464
3465 let dispatch_path = self
3466 .window
3467 .rendered_frame
3468 .dispatch_tree
3469 .dispatch_path(node_id);
3470
3471 'replay: for replay in replays {
3472 let event = KeyDownEvent {
3473 keystroke: replay.keystroke.clone(),
3474 is_held: false,
3475 };
3476
3477 self.propagate_event = true;
3478 for binding in replay.bindings {
3479 self.dispatch_action_on_node(node_id, binding.action.as_ref());
3480 if !self.propagate_event {
3481 self.dispatch_keystroke_observers(&event, Some(binding.action));
3482 continue 'replay;
3483 }
3484 }
3485
3486 self.dispatch_key_down_up_event(&event, &dispatch_path);
3487 if !self.propagate_event {
3488 continue 'replay;
3489 }
3490 if let Some(input) = replay.keystroke.key_char.as_ref().cloned() {
3491 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
3492 input_handler.dispatch_input(&input, self);
3493 self.window.platform_window.set_input_handler(input_handler)
3494 }
3495 }
3496 }
3497 }
3498
3499 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: &dyn Action) {
3500 let dispatch_path = self
3501 .window
3502 .rendered_frame
3503 .dispatch_tree
3504 .dispatch_path(node_id);
3505
3506 // Capture phase for global actions.
3507 self.propagate_event = true;
3508 if let Some(mut global_listeners) = self
3509 .global_action_listeners
3510 .remove(&action.as_any().type_id())
3511 {
3512 for listener in &global_listeners {
3513 listener(action.as_any(), DispatchPhase::Capture, self);
3514 if !self.propagate_event {
3515 break;
3516 }
3517 }
3518
3519 global_listeners.extend(
3520 self.global_action_listeners
3521 .remove(&action.as_any().type_id())
3522 .unwrap_or_default(),
3523 );
3524
3525 self.global_action_listeners
3526 .insert(action.as_any().type_id(), global_listeners);
3527 }
3528
3529 if !self.propagate_event {
3530 return;
3531 }
3532
3533 // Capture phase for window actions.
3534 for node_id in &dispatch_path {
3535 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3536 for DispatchActionListener {
3537 action_type,
3538 listener,
3539 } in node.action_listeners.clone()
3540 {
3541 let any_action = action.as_any();
3542 if action_type == any_action.type_id() {
3543 listener(any_action, DispatchPhase::Capture, self);
3544
3545 if !self.propagate_event {
3546 return;
3547 }
3548 }
3549 }
3550 }
3551
3552 // Bubble phase for window actions.
3553 for node_id in dispatch_path.iter().rev() {
3554 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3555 for DispatchActionListener {
3556 action_type,
3557 listener,
3558 } in node.action_listeners.clone()
3559 {
3560 let any_action = action.as_any();
3561 if action_type == any_action.type_id() {
3562 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
3563 listener(any_action, DispatchPhase::Bubble, self);
3564
3565 if !self.propagate_event {
3566 return;
3567 }
3568 }
3569 }
3570 }
3571
3572 // Bubble phase for global actions.
3573 if let Some(mut global_listeners) = self
3574 .global_action_listeners
3575 .remove(&action.as_any().type_id())
3576 {
3577 for listener in global_listeners.iter().rev() {
3578 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
3579
3580 listener(action.as_any(), DispatchPhase::Bubble, self);
3581 if !self.propagate_event {
3582 break;
3583 }
3584 }
3585
3586 global_listeners.extend(
3587 self.global_action_listeners
3588 .remove(&action.as_any().type_id())
3589 .unwrap_or_default(),
3590 );
3591
3592 self.global_action_listeners
3593 .insert(action.as_any().type_id(), global_listeners);
3594 }
3595 }
3596
3597 /// Register the given handler to be invoked whenever the global of the given type
3598 /// is updated.
3599 pub fn observe_global<G: Global>(
3600 &mut self,
3601 f: impl Fn(&mut WindowContext<'_>) + 'static,
3602 ) -> Subscription {
3603 let window_handle = self.window.handle;
3604 let (subscription, activate) = self.global_observers.insert(
3605 TypeId::of::<G>(),
3606 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
3607 );
3608 self.app.defer(move |_| activate());
3609 subscription
3610 }
3611
3612 /// Focus the current window and bring it to the foreground at the platform level.
3613 pub fn activate_window(&self) {
3614 self.window.platform_window.activate();
3615 }
3616
3617 /// Minimize the current window at the platform level.
3618 pub fn minimize_window(&self) {
3619 self.window.platform_window.minimize();
3620 }
3621
3622 /// Toggle full screen status on the current window at the platform level.
3623 pub fn toggle_fullscreen(&self) {
3624 self.window.platform_window.toggle_fullscreen();
3625 }
3626
3627 /// Updates the IME panel position suggestions for languages like japanese, chinese.
3628 pub fn invalidate_character_coordinates(&self) {
3629 self.on_next_frame(|cx| {
3630 if let Some(mut input_handler) = cx.window.platform_window.take_input_handler() {
3631 if let Some(bounds) = input_handler.selected_bounds(cx) {
3632 cx.window
3633 .platform_window
3634 .update_ime_position(bounds.scale(cx.scale_factor()));
3635 }
3636 cx.window.platform_window.set_input_handler(input_handler);
3637 }
3638 });
3639 }
3640
3641 /// Present a platform dialog.
3642 /// The provided message will be presented, along with buttons for each answer.
3643 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
3644 pub fn prompt(
3645 &mut self,
3646 level: PromptLevel,
3647 message: &str,
3648 detail: Option<&str>,
3649 answers: &[&str],
3650 ) -> oneshot::Receiver<usize> {
3651 let prompt_builder = self.app.prompt_builder.take();
3652 let Some(prompt_builder) = prompt_builder else {
3653 unreachable!("Re-entrant window prompting is not supported by GPUI");
3654 };
3655
3656 let receiver = match &prompt_builder {
3657 PromptBuilder::Default => self
3658 .window
3659 .platform_window
3660 .prompt(level, message, detail, answers)
3661 .unwrap_or_else(|| {
3662 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
3663 }),
3664 PromptBuilder::Custom(_) => {
3665 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
3666 }
3667 };
3668
3669 self.app.prompt_builder = Some(prompt_builder);
3670
3671 receiver
3672 }
3673
3674 fn build_custom_prompt(
3675 &mut self,
3676 prompt_builder: &PromptBuilder,
3677 level: PromptLevel,
3678 message: &str,
3679 detail: Option<&str>,
3680 answers: &[&str],
3681 ) -> oneshot::Receiver<usize> {
3682 let (sender, receiver) = oneshot::channel();
3683 let handle = PromptHandle::new(sender);
3684 let handle = (prompt_builder)(level, message, detail, answers, handle, self);
3685 self.window.prompt = Some(handle);
3686 receiver
3687 }
3688
3689 /// Returns the current context stack.
3690 pub fn context_stack(&self) -> Vec<KeyContext> {
3691 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
3692 let node_id = self
3693 .window
3694 .focus
3695 .and_then(|focus_id| dispatch_tree.focusable_node_id(focus_id))
3696 .unwrap_or_else(|| dispatch_tree.root_node_id());
3697
3698 dispatch_tree
3699 .dispatch_path(node_id)
3700 .iter()
3701 .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
3702 .collect()
3703 }
3704
3705 /// Returns all available actions for the focused element.
3706 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
3707 let node_id = self
3708 .window
3709 .focus
3710 .and_then(|focus_id| {
3711 self.window
3712 .rendered_frame
3713 .dispatch_tree
3714 .focusable_node_id(focus_id)
3715 })
3716 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3717
3718 let mut actions = self
3719 .window
3720 .rendered_frame
3721 .dispatch_tree
3722 .available_actions(node_id);
3723 for action_type in self.global_action_listeners.keys() {
3724 if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
3725 let action = self.actions.build_action_type(action_type).ok();
3726 if let Some(action) = action {
3727 actions.insert(ix, action);
3728 }
3729 }
3730 }
3731 actions
3732 }
3733
3734 /// Returns key bindings that invoke the given action on the currently focused element.
3735 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
3736 self.window
3737 .rendered_frame
3738 .dispatch_tree
3739 .bindings_for_action(
3740 action,
3741 &self.window.rendered_frame.dispatch_tree.context_stack,
3742 )
3743 }
3744
3745 /// Returns key bindings that invoke the given action on the currently focused element.
3746 pub fn all_bindings_for_input(&self, input: &[Keystroke]) -> Vec<KeyBinding> {
3747 RefCell::borrow(&self.keymap).all_bindings_for_input(input)
3748 }
3749
3750 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
3751 pub fn bindings_for_action_in(
3752 &self,
3753 action: &dyn Action,
3754 focus_handle: &FocusHandle,
3755 ) -> Vec<KeyBinding> {
3756 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
3757
3758 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
3759 return vec![];
3760 };
3761 let context_stack: Vec<_> = dispatch_tree
3762 .dispatch_path(node_id)
3763 .into_iter()
3764 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
3765 .collect();
3766 dispatch_tree.bindings_for_action(action, &context_stack)
3767 }
3768
3769 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
3770 pub fn listener_for<V: Render, E>(
3771 &self,
3772 view: &View<V>,
3773 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
3774 ) -> impl Fn(&E, &mut WindowContext) + 'static {
3775 let view = view.downgrade();
3776 move |e: &E, cx: &mut WindowContext| {
3777 view.update(cx, |view, cx| f(view, e, cx)).ok();
3778 }
3779 }
3780
3781 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
3782 pub fn handler_for<V: Render>(
3783 &self,
3784 view: &View<V>,
3785 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
3786 ) -> impl Fn(&mut WindowContext) {
3787 let view = view.downgrade();
3788 move |cx: &mut WindowContext| {
3789 view.update(cx, |view, cx| f(view, cx)).ok();
3790 }
3791 }
3792
3793 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
3794 /// If the callback returns false, the window won't be closed.
3795 pub fn on_window_should_close(&self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
3796 let mut this = self.to_async();
3797 self.window
3798 .platform_window
3799 .on_should_close(Box::new(move || this.update(|cx| f(cx)).unwrap_or(true)))
3800 }
3801
3802 /// Register an action listener on the window for the next frame. The type of action
3803 /// is determined by the first parameter of the given listener. When the next frame is rendered
3804 /// the listener will be cleared.
3805 ///
3806 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
3807 /// a specific need to register a global listener.
3808 pub fn on_action(
3809 &mut self,
3810 action_type: TypeId,
3811 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
3812 ) {
3813 self.window
3814 .next_frame
3815 .dispatch_tree
3816 .on_action(action_type, Rc::new(listener));
3817 }
3818
3819 /// Read information about the GPU backing this window.
3820 /// Currently returns None on Mac and Windows.
3821 pub fn gpu_specs(&self) -> Option<GPUSpecs> {
3822 self.window.platform_window.gpu_specs()
3823 }
3824}
3825
3826#[cfg(target_os = "windows")]
3827impl WindowContext<'_> {
3828 /// Returns the raw HWND handle for the window.
3829 pub fn get_raw_handle(&self) -> windows::Win32::Foundation::HWND {
3830 self.window.platform_window.get_raw_handle()
3831 }
3832}
3833
3834impl Context for WindowContext<'_> {
3835 type Result<T> = T;
3836
3837 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
3838 where
3839 T: 'static,
3840 {
3841 let slot = self.app.entities.reserve();
3842 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
3843 self.entities.insert(slot, model)
3844 }
3845
3846 fn reserve_model<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
3847 self.app.reserve_model()
3848 }
3849
3850 fn insert_model<T: 'static>(
3851 &mut self,
3852 reservation: crate::Reservation<T>,
3853 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
3854 ) -> Self::Result<Model<T>> {
3855 self.app.insert_model(reservation, build_model)
3856 }
3857
3858 fn update_model<T: 'static, R>(
3859 &mut self,
3860 model: &Model<T>,
3861 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
3862 ) -> R {
3863 let mut entity = self.entities.lease(model);
3864 let result = update(
3865 &mut *entity,
3866 &mut ModelContext::new(&mut *self.app, model.downgrade()),
3867 );
3868 self.entities.end_lease(entity);
3869 result
3870 }
3871
3872 fn read_model<T, R>(
3873 &self,
3874 handle: &Model<T>,
3875 read: impl FnOnce(&T, &AppContext) -> R,
3876 ) -> Self::Result<R>
3877 where
3878 T: 'static,
3879 {
3880 let entity = self.entities.read(handle);
3881 read(entity, &*self.app)
3882 }
3883
3884 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
3885 where
3886 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
3887 {
3888 if window == self.window.handle {
3889 let root_view = self.window.root_view.clone().unwrap();
3890 Ok(update(root_view, self))
3891 } else {
3892 window.update(self.app, update)
3893 }
3894 }
3895
3896 fn read_window<T, R>(
3897 &self,
3898 window: &WindowHandle<T>,
3899 read: impl FnOnce(View<T>, &AppContext) -> R,
3900 ) -> Result<R>
3901 where
3902 T: 'static,
3903 {
3904 if window.any_handle == self.window.handle {
3905 let root_view = self
3906 .window
3907 .root_view
3908 .clone()
3909 .unwrap()
3910 .downcast::<T>()
3911 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
3912 Ok(read(root_view, self))
3913 } else {
3914 self.app.read_window(window, read)
3915 }
3916 }
3917}
3918
3919impl VisualContext for WindowContext<'_> {
3920 fn new_view<V>(
3921 &mut self,
3922 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
3923 ) -> Self::Result<View<V>>
3924 where
3925 V: 'static + Render,
3926 {
3927 let slot = self.app.entities.reserve();
3928 let view = View {
3929 model: slot.clone(),
3930 };
3931 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
3932 let entity = build_view_state(&mut cx);
3933 cx.entities.insert(slot, entity);
3934
3935 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
3936 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
3937 cx.new_view_observers.clone().retain(&tid, |observer| {
3938 let any_view = view.clone();
3939 (observer)(any_view, cx);
3940 true
3941 });
3942 }
3943 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
3944
3945 view
3946 }
3947
3948 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
3949 fn update_view<T: 'static, R>(
3950 &mut self,
3951 view: &View<T>,
3952 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
3953 ) -> Self::Result<R> {
3954 let mut lease = self.app.entities.lease(&view.model);
3955 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
3956 let result = update(&mut *lease, &mut cx);
3957 cx.app.entities.end_lease(lease);
3958 result
3959 }
3960
3961 fn replace_root_view<V>(
3962 &mut self,
3963 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
3964 ) -> Self::Result<View<V>>
3965 where
3966 V: 'static + Render,
3967 {
3968 let view = self.new_view(build_view);
3969 self.window.root_view = Some(view.clone().into());
3970 self.refresh();
3971 view
3972 }
3973
3974 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
3975 self.update_view(view, |view, cx| {
3976 view.focus_handle(cx).clone().focus(cx);
3977 })
3978 }
3979
3980 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
3981 where
3982 V: ManagedView,
3983 {
3984 self.update_view(view, |_, cx| cx.emit(DismissEvent))
3985 }
3986}
3987
3988impl<'a> std::ops::Deref for WindowContext<'a> {
3989 type Target = AppContext;
3990
3991 fn deref(&self) -> &Self::Target {
3992 self.app
3993 }
3994}
3995
3996impl<'a> std::ops::DerefMut for WindowContext<'a> {
3997 fn deref_mut(&mut self) -> &mut Self::Target {
3998 self.app
3999 }
4000}
4001
4002impl<'a> Borrow<AppContext> for WindowContext<'a> {
4003 fn borrow(&self) -> &AppContext {
4004 self.app
4005 }
4006}
4007
4008impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
4009 fn borrow_mut(&mut self) -> &mut AppContext {
4010 self.app
4011 }
4012}
4013
4014/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
4015pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
4016 #[doc(hidden)]
4017 fn app_mut(&mut self) -> &mut AppContext {
4018 self.borrow_mut()
4019 }
4020
4021 #[doc(hidden)]
4022 fn app(&self) -> &AppContext {
4023 self.borrow()
4024 }
4025
4026 #[doc(hidden)]
4027 fn window(&self) -> &Window {
4028 self.borrow()
4029 }
4030
4031 #[doc(hidden)]
4032 fn window_mut(&mut self) -> &mut Window {
4033 self.borrow_mut()
4034 }
4035}
4036
4037impl Borrow<Window> for WindowContext<'_> {
4038 fn borrow(&self) -> &Window {
4039 self.window
4040 }
4041}
4042
4043impl BorrowMut<Window> for WindowContext<'_> {
4044 fn borrow_mut(&mut self) -> &mut Window {
4045 self.window
4046 }
4047}
4048
4049impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
4050
4051/// Provides access to application state that is specialized for a particular [`View`].
4052/// Allows you to interact with focus, emit events, etc.
4053/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
4054/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
4055pub struct ViewContext<'a, V> {
4056 window_cx: WindowContext<'a>,
4057 view: &'a View<V>,
4058}
4059
4060impl<V> Borrow<AppContext> for ViewContext<'_, V> {
4061 fn borrow(&self) -> &AppContext {
4062 &*self.window_cx.app
4063 }
4064}
4065
4066impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
4067 fn borrow_mut(&mut self) -> &mut AppContext {
4068 &mut *self.window_cx.app
4069 }
4070}
4071
4072impl<V> Borrow<Window> for ViewContext<'_, V> {
4073 fn borrow(&self) -> &Window {
4074 &*self.window_cx.window
4075 }
4076}
4077
4078impl<V> BorrowMut<Window> for ViewContext<'_, V> {
4079 fn borrow_mut(&mut self) -> &mut Window {
4080 &mut *self.window_cx.window
4081 }
4082}
4083
4084impl<'a, V: 'static> ViewContext<'a, V> {
4085 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
4086 Self {
4087 window_cx: WindowContext::new(app, window),
4088 view,
4089 }
4090 }
4091
4092 /// Get the entity_id of this view.
4093 pub fn entity_id(&self) -> EntityId {
4094 self.view.entity_id()
4095 }
4096
4097 /// Get the view pointer underlying this context.
4098 pub fn view(&self) -> &View<V> {
4099 self.view
4100 }
4101
4102 /// Get the model underlying this view.
4103 pub fn model(&self) -> &Model<V> {
4104 &self.view.model
4105 }
4106
4107 /// Access the underlying window context.
4108 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
4109 &mut self.window_cx
4110 }
4111
4112 /// Sets a given callback to be run on the next frame.
4113 pub fn on_next_frame(&self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
4114 where
4115 V: 'static,
4116 {
4117 let view = self.view().clone();
4118 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
4119 }
4120
4121 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
4122 /// that are currently on the stack to be returned to the app.
4123 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
4124 let view = self.view().downgrade();
4125 self.window_cx.defer(move |cx| {
4126 view.update(cx, f).ok();
4127 });
4128 }
4129
4130 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
4131 pub fn observe<V2, E>(
4132 &mut self,
4133 entity: &E,
4134 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
4135 ) -> Subscription
4136 where
4137 V2: 'static,
4138 V: 'static,
4139 E: Entity<V2>,
4140 {
4141 let view = self.view().downgrade();
4142 let entity_id = entity.entity_id();
4143 let entity = entity.downgrade();
4144 let window_handle = self.window.handle;
4145 self.app.new_observer(
4146 entity_id,
4147 Box::new(move |cx| {
4148 window_handle
4149 .update(cx, |_, cx| {
4150 if let Some(handle) = E::upgrade_from(&entity) {
4151 view.update(cx, |this, cx| on_notify(this, handle, cx))
4152 .is_ok()
4153 } else {
4154 false
4155 }
4156 })
4157 .unwrap_or(false)
4158 }),
4159 )
4160 }
4161
4162 /// Subscribe to events emitted by another model or view.
4163 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
4164 /// 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.
4165 pub fn subscribe<V2, E, Evt>(
4166 &mut self,
4167 entity: &E,
4168 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
4169 ) -> Subscription
4170 where
4171 V2: EventEmitter<Evt>,
4172 E: Entity<V2>,
4173 Evt: 'static,
4174 {
4175 let view = self.view().downgrade();
4176 let entity_id = entity.entity_id();
4177 let handle = entity.downgrade();
4178 let window_handle = self.window.handle;
4179 self.app.new_subscription(
4180 entity_id,
4181 (
4182 TypeId::of::<Evt>(),
4183 Box::new(move |event, cx| {
4184 window_handle
4185 .update(cx, |_, cx| {
4186 if let Some(handle) = E::upgrade_from(&handle) {
4187 let event = event.downcast_ref().expect("invalid event type");
4188 view.update(cx, |this, cx| on_event(this, handle, event, cx))
4189 .is_ok()
4190 } else {
4191 false
4192 }
4193 })
4194 .unwrap_or(false)
4195 }),
4196 ),
4197 )
4198 }
4199
4200 /// Register a callback to be invoked when the view is released.
4201 ///
4202 /// The callback receives a handle to the view's window. This handle may be
4203 /// invalid, if the window was closed before the view was released.
4204 pub fn on_release(
4205 &self,
4206 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
4207 ) -> Subscription {
4208 let window_handle = self.window.handle;
4209 let (subscription, activate) = self.app.release_listeners.insert(
4210 self.view.model.entity_id,
4211 Box::new(move |this, cx| {
4212 let this = this.downcast_mut().expect("invalid entity type");
4213 on_release(this, window_handle, cx)
4214 }),
4215 );
4216 activate();
4217 subscription
4218 }
4219
4220 /// Register a callback to be invoked when the given Model or View is released.
4221 pub fn observe_release<V2, E>(
4222 &self,
4223 entity: &E,
4224 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
4225 ) -> Subscription
4226 where
4227 V: 'static,
4228 V2: 'static,
4229 E: Entity<V2>,
4230 {
4231 let view = self.view().downgrade();
4232 let entity_id = entity.entity_id();
4233 let window_handle = self.window.handle;
4234 let (subscription, activate) = self.app.release_listeners.insert(
4235 entity_id,
4236 Box::new(move |entity, cx| {
4237 let entity = entity.downcast_mut().expect("invalid entity type");
4238 let _ = window_handle.update(cx, |_, cx| {
4239 view.update(cx, |this, cx| on_release(this, entity, cx))
4240 });
4241 }),
4242 );
4243 activate();
4244 subscription
4245 }
4246
4247 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
4248 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
4249 pub fn notify(&mut self) {
4250 self.window_cx.notify(Some(self.view.entity_id()));
4251 }
4252
4253 /// Register a callback to be invoked when the window is resized.
4254 pub fn observe_window_bounds(
4255 &self,
4256 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4257 ) -> Subscription {
4258 let view = self.view.downgrade();
4259 let (subscription, activate) = self.window.bounds_observers.insert(
4260 (),
4261 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4262 );
4263 activate();
4264 subscription
4265 }
4266
4267 /// Register a callback to be invoked when the window is activated or deactivated.
4268 pub fn observe_window_activation(
4269 &self,
4270 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4271 ) -> Subscription {
4272 let view = self.view.downgrade();
4273 let (subscription, activate) = self.window.activation_observers.insert(
4274 (),
4275 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4276 );
4277 activate();
4278 subscription
4279 }
4280
4281 /// Registers a callback to be invoked when the window appearance changes.
4282 pub fn observe_window_appearance(
4283 &self,
4284 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4285 ) -> Subscription {
4286 let view = self.view.downgrade();
4287 let (subscription, activate) = self.window.appearance_observers.insert(
4288 (),
4289 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4290 );
4291 activate();
4292 subscription
4293 }
4294
4295 /// Register a callback to be invoked when a keystroke is received by the application
4296 /// in any window. Note that this fires after all other action and event mechanisms have resolved
4297 /// and that this API will not be invoked if the event's propagation is stopped.
4298 pub fn observe_keystrokes(
4299 &mut self,
4300 mut f: impl FnMut(&mut V, &KeystrokeEvent, &mut ViewContext<V>) + 'static,
4301 ) -> Subscription {
4302 fn inner(
4303 keystroke_observers: &SubscriberSet<(), KeystrokeObserver>,
4304 handler: KeystrokeObserver,
4305 ) -> Subscription {
4306 let (subscription, activate) = keystroke_observers.insert((), handler);
4307 activate();
4308 subscription
4309 }
4310
4311 let view = self.view.downgrade();
4312 inner(
4313 &mut self.keystroke_observers,
4314 Box::new(move |event, cx| {
4315 if let Some(view) = view.upgrade() {
4316 view.update(cx, |view, cx| f(view, event, cx));
4317 true
4318 } else {
4319 false
4320 }
4321 }),
4322 )
4323 }
4324
4325 /// Register a callback to be invoked when the window's pending input changes.
4326 pub fn observe_pending_input(
4327 &self,
4328 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4329 ) -> Subscription {
4330 let view = self.view.downgrade();
4331 let (subscription, activate) = self.window.pending_input_observers.insert(
4332 (),
4333 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4334 );
4335 activate();
4336 subscription
4337 }
4338
4339 /// Register a listener to be called when the given focus handle receives focus.
4340 /// Returns a subscription and persists until the subscription is dropped.
4341 pub fn on_focus(
4342 &mut self,
4343 handle: &FocusHandle,
4344 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4345 ) -> Subscription {
4346 let view = self.view.downgrade();
4347 let focus_id = handle.id;
4348 let (subscription, activate) =
4349 self.window.new_focus_listener(Box::new(move |event, cx| {
4350 view.update(cx, |view, cx| {
4351 if event.previous_focus_path.last() != Some(&focus_id)
4352 && event.current_focus_path.last() == Some(&focus_id)
4353 {
4354 listener(view, cx)
4355 }
4356 })
4357 .is_ok()
4358 }));
4359 self.app.defer(|_| activate());
4360 subscription
4361 }
4362
4363 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
4364 /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
4365 /// Returns a subscription and persists until the subscription is dropped.
4366 pub fn on_focus_in(
4367 &mut self,
4368 handle: &FocusHandle,
4369 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4370 ) -> Subscription {
4371 let view = self.view.downgrade();
4372 let focus_id = handle.id;
4373 let (subscription, activate) =
4374 self.window.new_focus_listener(Box::new(move |event, cx| {
4375 view.update(cx, |view, cx| {
4376 if event.is_focus_in(focus_id) {
4377 listener(view, cx)
4378 }
4379 })
4380 .is_ok()
4381 }));
4382 self.app.defer(move |_| activate());
4383 subscription
4384 }
4385
4386 /// Register a listener to be called when the given focus handle loses focus.
4387 /// Returns a subscription and persists until the subscription is dropped.
4388 pub fn on_blur(
4389 &mut self,
4390 handle: &FocusHandle,
4391 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4392 ) -> Subscription {
4393 let view = self.view.downgrade();
4394 let focus_id = handle.id;
4395 let (subscription, activate) =
4396 self.window.new_focus_listener(Box::new(move |event, cx| {
4397 view.update(cx, |view, cx| {
4398 if event.previous_focus_path.last() == Some(&focus_id)
4399 && event.current_focus_path.last() != Some(&focus_id)
4400 {
4401 listener(view, cx)
4402 }
4403 })
4404 .is_ok()
4405 }));
4406 self.app.defer(move |_| activate());
4407 subscription
4408 }
4409
4410 /// Register a listener to be called when nothing in the window has focus.
4411 /// This typically happens when the node that was focused is removed from the tree,
4412 /// and this callback lets you chose a default place to restore the users focus.
4413 /// Returns a subscription and persists until the subscription is dropped.
4414 pub fn on_focus_lost(
4415 &self,
4416 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4417 ) -> Subscription {
4418 let view = self.view.downgrade();
4419 let (subscription, activate) = self.window.focus_lost_listeners.insert(
4420 (),
4421 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
4422 );
4423 activate();
4424 subscription
4425 }
4426
4427 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
4428 /// Returns a subscription and persists until the subscription is dropped.
4429 pub fn on_focus_out(
4430 &mut self,
4431 handle: &FocusHandle,
4432 mut listener: impl FnMut(&mut V, FocusOutEvent, &mut ViewContext<V>) + 'static,
4433 ) -> Subscription {
4434 let view = self.view.downgrade();
4435 let focus_id = handle.id;
4436 let (subscription, activate) =
4437 self.window.new_focus_listener(Box::new(move |event, cx| {
4438 view.update(cx, |view, cx| {
4439 if let Some(blurred_id) = event.previous_focus_path.last().copied() {
4440 if event.is_focus_out(focus_id) {
4441 let event = FocusOutEvent {
4442 blurred: WeakFocusHandle {
4443 id: blurred_id,
4444 handles: Arc::downgrade(&cx.window.focus_handles),
4445 },
4446 };
4447 listener(view, event, cx)
4448 }
4449 }
4450 })
4451 .is_ok()
4452 }));
4453 self.app.defer(move |_| activate());
4454 subscription
4455 }
4456
4457 /// Schedule a future to be run asynchronously.
4458 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
4459 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
4460 /// The returned future will be polled on the main thread.
4461 pub fn spawn<Fut, R>(&self, f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut) -> Task<R>
4462 where
4463 R: 'static,
4464 Fut: Future<Output = R> + 'static,
4465 {
4466 let view = self.view().downgrade();
4467 self.window_cx.spawn(|cx| f(view, cx))
4468 }
4469
4470 /// Register a callback to be invoked when the given global state changes.
4471 pub fn observe_global<G: Global>(
4472 &mut self,
4473 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
4474 ) -> Subscription {
4475 let window_handle = self.window.handle;
4476 let view = self.view().downgrade();
4477 let (subscription, activate) = self.global_observers.insert(
4478 TypeId::of::<G>(),
4479 Box::new(move |cx| {
4480 window_handle
4481 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
4482 .unwrap_or(false)
4483 }),
4484 );
4485 self.app.defer(move |_| activate());
4486 subscription
4487 }
4488
4489 /// Register a callback to be invoked when the given Action type is dispatched to the window.
4490 pub fn on_action(
4491 &mut self,
4492 action_type: TypeId,
4493 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
4494 ) {
4495 let handle = self.view().clone();
4496 self.window_cx
4497 .on_action(action_type, move |action, phase, cx| {
4498 handle.update(cx, |view, cx| {
4499 listener(view, action, phase, cx);
4500 })
4501 });
4502 }
4503
4504 /// Emit an event to be handled by any other views that have subscribed via [ViewContext::subscribe].
4505 pub fn emit<Evt>(&mut self, event: Evt)
4506 where
4507 Evt: 'static,
4508 V: EventEmitter<Evt>,
4509 {
4510 let emitter = self.view.model.entity_id;
4511 self.app.push_effect(Effect::Emit {
4512 emitter,
4513 event_type: TypeId::of::<Evt>(),
4514 event: Box::new(event),
4515 });
4516 }
4517
4518 /// Move focus to the current view, assuming it implements [`FocusableView`].
4519 pub fn focus_self(&mut self)
4520 where
4521 V: FocusableView,
4522 {
4523 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
4524 }
4525
4526 /// Convenience method for accessing view state in an event callback.
4527 ///
4528 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
4529 /// but it's often useful to be able to access view state in these
4530 /// callbacks. This method provides a convenient way to do so.
4531 pub fn listener<E: ?Sized>(
4532 &self,
4533 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
4534 ) -> impl Fn(&E, &mut WindowContext) + 'static {
4535 let view = self.view().downgrade();
4536 move |e: &E, cx: &mut WindowContext| {
4537 view.update(cx, |view, cx| f(view, e, cx)).ok();
4538 }
4539 }
4540}
4541
4542impl<V> Context for ViewContext<'_, V> {
4543 type Result<U> = U;
4544
4545 fn new_model<T: 'static>(
4546 &mut self,
4547 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
4548 ) -> Model<T> {
4549 self.window_cx.new_model(build_model)
4550 }
4551
4552 fn reserve_model<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
4553 self.window_cx.reserve_model()
4554 }
4555
4556 fn insert_model<T: 'static>(
4557 &mut self,
4558 reservation: crate::Reservation<T>,
4559 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
4560 ) -> Self::Result<Model<T>> {
4561 self.window_cx.insert_model(reservation, build_model)
4562 }
4563
4564 fn update_model<T: 'static, R>(
4565 &mut self,
4566 model: &Model<T>,
4567 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
4568 ) -> R {
4569 self.window_cx.update_model(model, update)
4570 }
4571
4572 fn read_model<T, R>(
4573 &self,
4574 handle: &Model<T>,
4575 read: impl FnOnce(&T, &AppContext) -> R,
4576 ) -> Self::Result<R>
4577 where
4578 T: 'static,
4579 {
4580 self.window_cx.read_model(handle, read)
4581 }
4582
4583 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
4584 where
4585 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
4586 {
4587 self.window_cx.update_window(window, update)
4588 }
4589
4590 fn read_window<T, R>(
4591 &self,
4592 window: &WindowHandle<T>,
4593 read: impl FnOnce(View<T>, &AppContext) -> R,
4594 ) -> Result<R>
4595 where
4596 T: 'static,
4597 {
4598 self.window_cx.read_window(window, read)
4599 }
4600}
4601
4602impl<V: 'static> VisualContext for ViewContext<'_, V> {
4603 fn new_view<W: Render + 'static>(
4604 &mut self,
4605 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
4606 ) -> Self::Result<View<W>> {
4607 self.window_cx.new_view(build_view_state)
4608 }
4609
4610 fn update_view<V2: 'static, R>(
4611 &mut self,
4612 view: &View<V2>,
4613 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
4614 ) -> Self::Result<R> {
4615 self.window_cx.update_view(view, update)
4616 }
4617
4618 fn replace_root_view<W>(
4619 &mut self,
4620 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
4621 ) -> Self::Result<View<W>>
4622 where
4623 W: 'static + Render,
4624 {
4625 self.window_cx.replace_root_view(build_view)
4626 }
4627
4628 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
4629 self.window_cx.focus_view(view)
4630 }
4631
4632 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
4633 self.window_cx.dismiss_view(view)
4634 }
4635}
4636
4637impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
4638 type Target = WindowContext<'a>;
4639
4640 fn deref(&self) -> &Self::Target {
4641 &self.window_cx
4642 }
4643}
4644
4645impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
4646 fn deref_mut(&mut self) -> &mut Self::Target {
4647 &mut self.window_cx
4648 }
4649}
4650
4651// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4652slotmap::new_key_type! {
4653 /// A unique identifier for a window.
4654 pub struct WindowId;
4655}
4656
4657impl WindowId {
4658 /// Converts this window ID to a `u64`.
4659 pub fn as_u64(&self) -> u64 {
4660 self.0.as_ffi()
4661 }
4662}
4663
4664impl From<u64> for WindowId {
4665 fn from(value: u64) -> Self {
4666 WindowId(slotmap::KeyData::from_ffi(value))
4667 }
4668}
4669
4670/// A handle to a window with a specific root view type.
4671/// Note that this does not keep the window alive on its own.
4672#[derive(Deref, DerefMut)]
4673pub struct WindowHandle<V> {
4674 #[deref]
4675 #[deref_mut]
4676 pub(crate) any_handle: AnyWindowHandle,
4677 state_type: PhantomData<V>,
4678}
4679
4680impl<V: 'static + Render> WindowHandle<V> {
4681 /// Creates a new handle from a window ID.
4682 /// This does not check if the root type of the window is `V`.
4683 pub fn new(id: WindowId) -> Self {
4684 WindowHandle {
4685 any_handle: AnyWindowHandle {
4686 id,
4687 state_type: TypeId::of::<V>(),
4688 },
4689 state_type: PhantomData,
4690 }
4691 }
4692
4693 /// Get the root view out of this window.
4694 ///
4695 /// This will fail if the window is closed or if the root view's type does not match `V`.
4696 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
4697 where
4698 C: Context,
4699 {
4700 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
4701 root_view
4702 .downcast::<V>()
4703 .map_err(|_| anyhow!("the type of the window's root view has changed"))
4704 }))
4705 }
4706
4707 /// Updates the root view of this window.
4708 ///
4709 /// This will fail if the window has been closed or if the root view's type does not match
4710 pub fn update<C, R>(
4711 &self,
4712 cx: &mut C,
4713 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
4714 ) -> Result<R>
4715 where
4716 C: Context,
4717 {
4718 cx.update_window(self.any_handle, |root_view, cx| {
4719 let view = root_view
4720 .downcast::<V>()
4721 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4722 Ok(cx.update_view(&view, update))
4723 })?
4724 }
4725
4726 /// Read the root view out of this window.
4727 ///
4728 /// This will fail if the window is closed or if the root view's type does not match `V`.
4729 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
4730 let x = cx
4731 .windows
4732 .get(self.id)
4733 .and_then(|window| {
4734 window
4735 .as_ref()
4736 .and_then(|window| window.root_view.clone())
4737 .map(|root_view| root_view.downcast::<V>())
4738 })
4739 .ok_or_else(|| anyhow!("window not found"))?
4740 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4741
4742 Ok(x.read(cx))
4743 }
4744
4745 /// Read the root view out of this window, with a callback
4746 ///
4747 /// This will fail if the window is closed or if the root view's type does not match `V`.
4748 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
4749 where
4750 C: Context,
4751 {
4752 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4753 }
4754
4755 /// Read the root view pointer off of this window.
4756 ///
4757 /// This will fail if the window is closed or if the root view's type does not match `V`.
4758 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
4759 where
4760 C: Context,
4761 {
4762 cx.read_window(self, |root_view, _cx| root_view.clone())
4763 }
4764
4765 /// Check if this window is 'active'.
4766 ///
4767 /// Will return `None` if the window is closed or currently
4768 /// borrowed.
4769 pub fn is_active(&self, cx: &mut AppContext) -> Option<bool> {
4770 cx.update_window(self.any_handle, |_, cx| cx.is_window_active())
4771 .ok()
4772 }
4773}
4774
4775impl<V> Copy for WindowHandle<V> {}
4776
4777impl<V> Clone for WindowHandle<V> {
4778 fn clone(&self) -> Self {
4779 *self
4780 }
4781}
4782
4783impl<V> PartialEq for WindowHandle<V> {
4784 fn eq(&self, other: &Self) -> bool {
4785 self.any_handle == other.any_handle
4786 }
4787}
4788
4789impl<V> Eq for WindowHandle<V> {}
4790
4791impl<V> Hash for WindowHandle<V> {
4792 fn hash<H: Hasher>(&self, state: &mut H) {
4793 self.any_handle.hash(state);
4794 }
4795}
4796
4797impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
4798 fn from(val: WindowHandle<V>) -> Self {
4799 val.any_handle
4800 }
4801}
4802
4803unsafe impl<V> Send for WindowHandle<V> {}
4804unsafe impl<V> Sync for WindowHandle<V> {}
4805
4806/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
4807#[derive(Copy, Clone, PartialEq, Eq, Hash)]
4808pub struct AnyWindowHandle {
4809 pub(crate) id: WindowId,
4810 state_type: TypeId,
4811}
4812
4813impl AnyWindowHandle {
4814 /// Get the ID of this window.
4815 pub fn window_id(&self) -> WindowId {
4816 self.id
4817 }
4818
4819 /// Attempt to convert this handle to a window handle with a specific root view type.
4820 /// If the types do not match, this will return `None`.
4821 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
4822 if TypeId::of::<T>() == self.state_type {
4823 Some(WindowHandle {
4824 any_handle: *self,
4825 state_type: PhantomData,
4826 })
4827 } else {
4828 None
4829 }
4830 }
4831
4832 /// Updates the state of the root view of this window.
4833 ///
4834 /// This will fail if the window has been closed.
4835 pub fn update<C, R>(
4836 self,
4837 cx: &mut C,
4838 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
4839 ) -> Result<R>
4840 where
4841 C: Context,
4842 {
4843 cx.update_window(self, update)
4844 }
4845
4846 /// Read the state of the root view of this window.
4847 ///
4848 /// This will fail if the window has been closed.
4849 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
4850 where
4851 C: Context,
4852 T: 'static,
4853 {
4854 let view = self
4855 .downcast::<T>()
4856 .context("the type of the window's root view has changed")?;
4857
4858 cx.read_window(&view, read)
4859 }
4860}
4861
4862/// An identifier for an [`Element`](crate::Element).
4863///
4864/// Can be constructed with a string, a number, or both, as well
4865/// as other internal representations.
4866#[derive(Clone, Debug, Eq, PartialEq, Hash)]
4867pub enum ElementId {
4868 /// The ID of a View element
4869 View(EntityId),
4870 /// An integer ID.
4871 Integer(usize),
4872 /// A string based ID.
4873 Name(SharedString),
4874 /// A UUID.
4875 Uuid(Uuid),
4876 /// An ID that's equated with a focus handle.
4877 FocusHandle(FocusId),
4878 /// A combination of a name and an integer.
4879 NamedInteger(SharedString, usize),
4880}
4881
4882impl Display for ElementId {
4883 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4884 match self {
4885 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
4886 ElementId::Integer(ix) => write!(f, "{}", ix)?,
4887 ElementId::Name(name) => write!(f, "{}", name)?,
4888 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
4889 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
4890 ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
4891 }
4892
4893 Ok(())
4894 }
4895}
4896
4897impl TryInto<SharedString> for ElementId {
4898 type Error = anyhow::Error;
4899
4900 fn try_into(self) -> anyhow::Result<SharedString> {
4901 if let ElementId::Name(name) = self {
4902 Ok(name)
4903 } else {
4904 Err(anyhow!("element id is not string"))
4905 }
4906 }
4907}
4908
4909impl From<usize> for ElementId {
4910 fn from(id: usize) -> Self {
4911 ElementId::Integer(id)
4912 }
4913}
4914
4915impl From<i32> for ElementId {
4916 fn from(id: i32) -> Self {
4917 Self::Integer(id as usize)
4918 }
4919}
4920
4921impl From<SharedString> for ElementId {
4922 fn from(name: SharedString) -> Self {
4923 ElementId::Name(name)
4924 }
4925}
4926
4927impl From<&'static str> for ElementId {
4928 fn from(name: &'static str) -> Self {
4929 ElementId::Name(name.into())
4930 }
4931}
4932
4933impl<'a> From<&'a FocusHandle> for ElementId {
4934 fn from(handle: &'a FocusHandle) -> Self {
4935 ElementId::FocusHandle(handle.id)
4936 }
4937}
4938
4939impl From<(&'static str, EntityId)> for ElementId {
4940 fn from((name, id): (&'static str, EntityId)) -> Self {
4941 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
4942 }
4943}
4944
4945impl From<(&'static str, usize)> for ElementId {
4946 fn from((name, id): (&'static str, usize)) -> Self {
4947 ElementId::NamedInteger(name.into(), id)
4948 }
4949}
4950
4951impl From<(SharedString, usize)> for ElementId {
4952 fn from((name, id): (SharedString, usize)) -> Self {
4953 ElementId::NamedInteger(name, id)
4954 }
4955}
4956
4957impl From<(&'static str, u64)> for ElementId {
4958 fn from((name, id): (&'static str, u64)) -> Self {
4959 ElementId::NamedInteger(name.into(), id as usize)
4960 }
4961}
4962
4963impl From<Uuid> for ElementId {
4964 fn from(value: Uuid) -> Self {
4965 Self::Uuid(value)
4966 }
4967}
4968
4969impl From<(&'static str, u32)> for ElementId {
4970 fn from((name, id): (&'static str, u32)) -> Self {
4971 ElementId::NamedInteger(name.into(), id as usize)
4972 }
4973}
4974
4975/// A rectangle to be rendered in the window at the given position and size.
4976/// Passed as an argument [`WindowContext::paint_quad`].
4977#[derive(Clone)]
4978pub struct PaintQuad {
4979 /// The bounds of the quad within the window.
4980 pub bounds: Bounds<Pixels>,
4981 /// The radii of the quad's corners.
4982 pub corner_radii: Corners<Pixels>,
4983 /// The background color of the quad.
4984 pub background: Background,
4985 /// The widths of the quad's borders.
4986 pub border_widths: Edges<Pixels>,
4987 /// The color of the quad's borders.
4988 pub border_color: Hsla,
4989}
4990
4991impl PaintQuad {
4992 /// Sets the corner radii of the quad.
4993 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
4994 PaintQuad {
4995 corner_radii: corner_radii.into(),
4996 ..self
4997 }
4998 }
4999
5000 /// Sets the border widths of the quad.
5001 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
5002 PaintQuad {
5003 border_widths: border_widths.into(),
5004 ..self
5005 }
5006 }
5007
5008 /// Sets the border color of the quad.
5009 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
5010 PaintQuad {
5011 border_color: border_color.into(),
5012 ..self
5013 }
5014 }
5015
5016 /// Sets the background color of the quad.
5017 pub fn background(self, background: impl Into<Background>) -> Self {
5018 PaintQuad {
5019 background: background.into(),
5020 ..self
5021 }
5022 }
5023}
5024
5025/// Creates a quad with the given parameters.
5026pub fn quad(
5027 bounds: Bounds<Pixels>,
5028 corner_radii: impl Into<Corners<Pixels>>,
5029 background: impl Into<Background>,
5030 border_widths: impl Into<Edges<Pixels>>,
5031 border_color: impl Into<Hsla>,
5032) -> PaintQuad {
5033 PaintQuad {
5034 bounds,
5035 corner_radii: corner_radii.into(),
5036 background: background.into(),
5037 border_widths: border_widths.into(),
5038 border_color: border_color.into(),
5039 }
5040}
5041
5042/// Creates a filled quad with the given bounds and background color.
5043pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
5044 PaintQuad {
5045 bounds: bounds.into(),
5046 corner_radii: (0.).into(),
5047 background: background.into(),
5048 border_widths: (0.).into(),
5049 border_color: transparent_black(),
5050 }
5051}
5052
5053/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
5054pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
5055 PaintQuad {
5056 bounds: bounds.into(),
5057 corner_radii: (0.).into(),
5058 background: transparent_black().into(),
5059 border_widths: (1.).into(),
5060 border_color: border_color.into(),
5061 }
5062}