window.rs

  1use crate::{
  2    image_cache::RenderImageParams, px, AnyView, AppContext, AsyncWindowContext, AvailableSpace,
  3    BorrowAppContext, Bounds, Context, Corners, DevicePixels, DisplayId, Effect, Element, EntityId,
  4    FontId, GlyphId, Handle, Hsla, ImageData, IsZero, LayerId, LayoutId, MainThread,
  5    MainThreadOnly, MonochromeSprite, Pixels, PlatformAtlas, PlatformWindow, Point,
  6    PolychromeSprite, Reference, RenderGlyphParams, RenderSvgParams, ScaledPixels, Scene,
  7    SharedString, Size, Style, TaffyLayoutEngine, Task, WeakHandle, WindowOptions,
  8    SUBPIXEL_VARIANTS,
  9};
 10use anyhow::Result;
 11use smallvec::SmallVec;
 12use std::{any::TypeId, borrow::Cow, future::Future, marker::PhantomData, mem, sync::Arc};
 13use util::ResultExt;
 14
 15pub struct AnyWindow {}
 16
 17pub struct Window {
 18    handle: AnyWindowHandle,
 19    platform_window: MainThreadOnly<Box<dyn PlatformWindow>>,
 20    pub(crate) display_id: DisplayId, // todo!("make private again?")
 21    sprite_atlas: Arc<dyn PlatformAtlas>,
 22    rem_size: Pixels,
 23    content_size: Size<Pixels>,
 24    layout_engine: TaffyLayoutEngine,
 25    pub(crate) root_view: Option<AnyView<()>>,
 26    mouse_position: Point<Pixels>,
 27    current_layer_id: LayerId,
 28    content_mask_stack: Vec<ContentMask>,
 29    pub(crate) scene: Scene,
 30    pub(crate) dirty: bool,
 31}
 32
 33impl Window {
 34    pub fn new(
 35        handle: AnyWindowHandle,
 36        options: WindowOptions,
 37        cx: &mut MainThread<AppContext>,
 38    ) -> Self {
 39        let platform_window = cx.platform().open_window(handle, options);
 40        let display_id = platform_window.display().id();
 41        let sprite_atlas = platform_window.sprite_atlas();
 42        let mouse_position = platform_window.mouse_position();
 43        let content_size = platform_window.content_size();
 44        let scale_factor = platform_window.scale_factor();
 45        platform_window.on_resize(Box::new({
 46            let handle = handle;
 47            let cx = cx.to_async();
 48            move |content_size, scale_factor| {
 49                cx.update_window(handle, |cx| {
 50                    cx.window.scene = Scene::new(scale_factor);
 51                    cx.window.content_size = content_size;
 52                    cx.window.display_id = cx
 53                        .window
 54                        .platform_window
 55                        .borrow_on_main_thread()
 56                        .display()
 57                        .id();
 58                    cx.window.dirty = true;
 59                })
 60                .log_err();
 61            }
 62        }));
 63
 64        let platform_window = MainThreadOnly::new(Arc::new(platform_window), cx.executor.clone());
 65
 66        Window {
 67            handle,
 68            platform_window,
 69            display_id,
 70            sprite_atlas,
 71            rem_size: px(16.),
 72            content_size,
 73            layout_engine: TaffyLayoutEngine::new(),
 74            root_view: None,
 75            mouse_position,
 76            current_layer_id: SmallVec::new(),
 77            content_mask_stack: Vec::new(),
 78            scene: Scene::new(scale_factor),
 79            dirty: true,
 80        }
 81    }
 82}
 83
 84#[derive(Clone, Debug)]
 85pub struct ContentMask {
 86    pub bounds: Bounds<Pixels>,
 87}
 88
 89impl ContentMask {
 90    pub fn scale(&self, factor: f32) -> ScaledContentMask {
 91        ScaledContentMask {
 92            bounds: self.bounds.scale(factor),
 93        }
 94    }
 95
 96    pub fn intersect(&self, other: &Self) -> Self {
 97        let bounds = self.bounds.intersect(&other.bounds);
 98        ContentMask { bounds }
 99    }
100}
101
102#[derive(Clone, Debug, PartialEq, Eq)]
103#[repr(C)]
104pub struct ScaledContentMask {
105    bounds: Bounds<ScaledPixels>,
106}
107
108pub struct WindowContext<'a, 'w> {
109    app: Reference<'a, AppContext>,
110    window: Reference<'w, Window>,
111}
112
113impl<'a, 'w> WindowContext<'a, 'w> {
114    pub(crate) fn mutable(app: &'a mut AppContext, window: &'w mut Window) -> Self {
115        Self {
116            app: Reference::Mutable(app),
117            window: Reference::Mutable(window),
118        }
119    }
120
121    pub fn notify(&mut self) {
122        self.window.dirty = true;
123    }
124
125    pub fn run_on_main<R>(
126        &mut self,
127        f: impl FnOnce(&mut MainThread<WindowContext<'_, '_>>) -> R + Send + 'static,
128    ) -> Task<Result<R>>
129    where
130        R: Send + 'static,
131    {
132        if self.executor.is_main_thread() {
133            Task::ready(Ok(f(unsafe {
134                mem::transmute::<&mut Self, &mut MainThread<Self>>(self)
135            })))
136        } else {
137            let id = self.window.handle.id;
138            self.app.run_on_main(move |cx| cx.update_window(id, f))
139        }
140    }
141
142    pub fn to_async(&self) -> AsyncWindowContext {
143        AsyncWindowContext::new(self.app.to_async(), self.window.handle)
144    }
145
146    pub fn on_next_frame(&mut self, f: impl FnOnce(&mut WindowContext) + Send + 'static) {
147        let cx = self.to_async();
148        let display_id = self.window.display_id;
149        self.display_linker.on_next_frame(display_id, move |_, _| {
150            cx.update(f).ok();
151        });
152    }
153
154    pub fn spawn<Fut, R>(
155        &mut self,
156        f: impl FnOnce(AnyWindowHandle, AsyncWindowContext) -> Fut + Send + 'static,
157    ) -> Task<R>
158    where
159        R: Send + 'static,
160        Fut: Future<Output = R> + Send + 'static,
161    {
162        let window = self.window.handle;
163        self.app.spawn(move |app| {
164            let cx = AsyncWindowContext::new(app, window);
165            let future = f(window, cx);
166            async move { future.await }
167        })
168    }
169
170    pub fn request_layout(
171        &mut self,
172        style: Style,
173        children: impl IntoIterator<Item = LayoutId>,
174    ) -> Result<LayoutId> {
175        self.app.layout_id_buffer.clear();
176        self.app.layout_id_buffer.extend(children.into_iter());
177        let rem_size = self.rem_size();
178
179        self.window
180            .layout_engine
181            .request_layout(style, rem_size, &self.app.layout_id_buffer)
182    }
183
184    pub fn request_measured_layout<
185        F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
186    >(
187        &mut self,
188        style: Style,
189        rem_size: Pixels,
190        measure: F,
191    ) -> Result<LayoutId> {
192        self.window
193            .layout_engine
194            .request_measured_layout(style, rem_size, measure)
195    }
196
197    pub fn layout(&mut self, layout_id: LayoutId) -> Result<Layout> {
198        Ok(self
199            .window
200            .layout_engine
201            .layout(layout_id)
202            .map(Into::into)?)
203    }
204
205    pub fn scale_factor(&self) -> f32 {
206        self.window.scene.scale_factor
207    }
208
209    pub fn rem_size(&self) -> Pixels {
210        self.window.rem_size
211    }
212
213    pub fn mouse_position(&self) -> Point<Pixels> {
214        self.window.mouse_position
215    }
216
217    pub fn scene(&mut self) -> &mut Scene {
218        &mut self.window.scene
219    }
220
221    pub fn stack<R>(&mut self, order: u32, f: impl FnOnce(&mut Self) -> R) -> R {
222        self.window.current_layer_id.push(order);
223        let result = f(self);
224        self.window.current_layer_id.pop();
225        result
226    }
227
228    pub fn current_layer_id(&self) -> LayerId {
229        self.window.current_layer_id.clone()
230    }
231
232    pub fn paint_glyph(
233        &mut self,
234        origin: Point<Pixels>,
235        order: u32,
236        font_id: FontId,
237        glyph_id: GlyphId,
238        font_size: Pixels,
239        color: Hsla,
240    ) -> Result<()> {
241        let scale_factor = self.scale_factor();
242        let glyph_origin = origin.scale(scale_factor);
243        let subpixel_variant = Point {
244            x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
245            y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
246        };
247        let params = RenderGlyphParams {
248            font_id,
249            glyph_id,
250            font_size,
251            subpixel_variant,
252            scale_factor,
253            is_emoji: false,
254        };
255
256        let raster_bounds = self.text_system().raster_bounds(&params)?;
257        if !raster_bounds.is_zero() {
258            let layer_id = self.current_layer_id();
259            let tile =
260                self.window
261                    .sprite_atlas
262                    .get_or_insert_with(&params.clone().into(), &mut || {
263                        let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
264                        Ok((size, Cow::Owned(bytes)))
265                    })?;
266            let bounds = Bounds {
267                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
268                size: tile.bounds.size.map(Into::into),
269            };
270            let content_mask = self.content_mask().scale(scale_factor);
271
272            self.window.scene.insert(
273                layer_id,
274                MonochromeSprite {
275                    order,
276                    bounds,
277                    content_mask,
278                    color,
279                    tile,
280                },
281            );
282        }
283        Ok(())
284    }
285
286    pub fn paint_emoji(
287        &mut self,
288        origin: Point<Pixels>,
289        order: u32,
290        font_id: FontId,
291        glyph_id: GlyphId,
292        font_size: Pixels,
293    ) -> Result<()> {
294        let scale_factor = self.scale_factor();
295        let glyph_origin = origin.scale(scale_factor);
296        let params = RenderGlyphParams {
297            font_id,
298            glyph_id,
299            font_size,
300            // We don't render emojis with subpixel variants.
301            subpixel_variant: Default::default(),
302            scale_factor,
303            is_emoji: true,
304        };
305
306        let raster_bounds = self.text_system().raster_bounds(&params)?;
307        if !raster_bounds.is_zero() {
308            let layer_id = self.current_layer_id();
309            let tile =
310                self.window
311                    .sprite_atlas
312                    .get_or_insert_with(&params.clone().into(), &mut || {
313                        let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
314                        Ok((size, Cow::Owned(bytes)))
315                    })?;
316            let bounds = Bounds {
317                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
318                size: tile.bounds.size.map(Into::into),
319            };
320            let content_mask = self.content_mask().scale(scale_factor);
321
322            self.window.scene.insert(
323                layer_id,
324                PolychromeSprite {
325                    order,
326                    bounds,
327                    corner_radii: Default::default(),
328                    content_mask,
329                    tile,
330                    grayscale: false,
331                },
332            );
333        }
334        Ok(())
335    }
336
337    pub fn paint_svg(
338        &mut self,
339        bounds: Bounds<Pixels>,
340        order: u32,
341        path: SharedString,
342        color: Hsla,
343    ) -> Result<()> {
344        let scale_factor = self.scale_factor();
345        let bounds = bounds.scale(scale_factor);
346        // Render the SVG at twice the size to get a higher quality result.
347        let params = RenderSvgParams {
348            path,
349            size: bounds
350                .size
351                .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
352        };
353
354        let layer_id = self.current_layer_id();
355        let tile =
356            self.window
357                .sprite_atlas
358                .get_or_insert_with(&params.clone().into(), &mut || {
359                    let bytes = self.svg_renderer.render(&params)?;
360                    Ok((params.size, Cow::Owned(bytes)))
361                })?;
362        let content_mask = self.content_mask().scale(scale_factor);
363
364        self.window.scene.insert(
365            layer_id,
366            MonochromeSprite {
367                order,
368                bounds,
369                content_mask,
370                color,
371                tile,
372            },
373        );
374
375        Ok(())
376    }
377
378    pub fn paint_image(
379        &mut self,
380        bounds: Bounds<Pixels>,
381        corner_radii: Corners<Pixels>,
382        order: u32,
383        data: Arc<ImageData>,
384        grayscale: bool,
385    ) -> Result<()> {
386        let scale_factor = self.scale_factor();
387        let bounds = bounds.scale(scale_factor);
388        let params = RenderImageParams { image_id: data.id };
389
390        let layer_id = self.current_layer_id();
391        let tile = self
392            .window
393            .sprite_atlas
394            .get_or_insert_with(&params.clone().into(), &mut || {
395                Ok((data.size(), Cow::Borrowed(data.as_bytes())))
396            })?;
397        let content_mask = self.content_mask().scale(scale_factor);
398        let corner_radii = corner_radii.scale(scale_factor);
399
400        self.window.scene.insert(
401            layer_id,
402            PolychromeSprite {
403                order,
404                bounds,
405                content_mask,
406                corner_radii,
407                tile,
408                grayscale,
409            },
410        );
411
412        Ok(())
413    }
414
415    pub(crate) fn draw(&mut self) -> Result<()> {
416        let unit_entity = self.unit_entity.clone();
417        self.update_entity(&unit_entity, |view, cx| {
418            let mut root_view = cx.window.root_view.take().unwrap();
419            let (root_layout_id, mut frame_state) = root_view.layout(&mut (), cx)?;
420            let available_space = cx.window.content_size.map(Into::into);
421
422            cx.window
423                .layout_engine
424                .compute_layout(root_layout_id, available_space)?;
425            let layout = cx.window.layout_engine.layout(root_layout_id)?;
426
427            root_view.paint(layout, &mut (), &mut frame_state, cx)?;
428            cx.window.root_view = Some(root_view);
429            let scene = cx.window.scene.take();
430
431            cx.run_on_main(view, |_, cx| {
432                cx.window
433                    .platform_window
434                    .borrow_on_main_thread()
435                    .draw(scene);
436                cx.window.dirty = false;
437            })
438            .detach();
439
440            Ok(())
441        })
442    }
443}
444
445impl Context for WindowContext<'_, '_> {
446    type EntityContext<'a, 'w, T: 'static + Send + Sync> = ViewContext<'a, 'w, T>;
447    type Result<T> = T;
448
449    fn entity<T: Send + Sync + 'static>(
450        &mut self,
451        build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T>) -> T,
452    ) -> Handle<T> {
453        let slot = self.app.entities.reserve();
454        let entity = build_entity(&mut ViewContext::mutable(
455            &mut *self.app,
456            &mut self.window,
457            slot.id,
458        ));
459        self.entities.insert(slot, entity)
460    }
461
462    fn update_entity<T: Send + Sync + 'static, R>(
463        &mut self,
464        handle: &Handle<T>,
465        update: impl FnOnce(&mut T, &mut Self::EntityContext<'_, '_, T>) -> R,
466    ) -> R {
467        let mut entity = self.entities.lease(handle);
468        let result = update(
469            &mut *entity,
470            &mut ViewContext::mutable(&mut *self.app, &mut *self.window, handle.id),
471        );
472        self.entities.end_lease(entity);
473        result
474    }
475}
476
477impl<'a, 'w> std::ops::Deref for WindowContext<'a, 'w> {
478    type Target = AppContext;
479
480    fn deref(&self) -> &Self::Target {
481        &self.app
482    }
483}
484
485impl<'a, 'w> std::ops::DerefMut for WindowContext<'a, 'w> {
486    fn deref_mut(&mut self) -> &mut Self::Target {
487        &mut self.app
488    }
489}
490
491impl BorrowAppContext for WindowContext<'_, '_> {
492    fn app_mut(&mut self) -> &mut AppContext {
493        &mut *self.app
494    }
495}
496
497pub trait BorrowWindow: BorrowAppContext {
498    fn window(&self) -> &Window;
499    fn window_mut(&mut self) -> &mut Window;
500
501    fn with_content_mask<R>(&mut self, mask: ContentMask, f: impl FnOnce(&mut Self) -> R) -> R {
502        let mask = mask.intersect(&self.content_mask());
503        self.window_mut().content_mask_stack.push(mask);
504        let result = f(self);
505        self.window_mut().content_mask_stack.pop();
506        result
507    }
508
509    fn content_mask(&self) -> ContentMask {
510        self.window()
511            .content_mask_stack
512            .last()
513            .cloned()
514            .unwrap_or_else(|| ContentMask {
515                bounds: Bounds {
516                    origin: Point::default(),
517                    size: self.window().content_size,
518                },
519            })
520    }
521
522    fn rem_size(&self) -> Pixels {
523        self.window().rem_size
524    }
525}
526
527impl BorrowWindow for WindowContext<'_, '_> {
528    fn window(&self) -> &Window {
529        &*self.window
530    }
531
532    fn window_mut(&mut self) -> &mut Window {
533        &mut *self.window
534    }
535}
536
537pub struct ViewContext<'a, 'w, S> {
538    window_cx: WindowContext<'a, 'w>,
539    entity_type: PhantomData<S>,
540    entity_id: EntityId,
541}
542
543impl<S> BorrowAppContext for ViewContext<'_, '_, S> {
544    fn app_mut(&mut self) -> &mut AppContext {
545        &mut *self.window_cx.app
546    }
547
548    fn with_text_style<F, R>(&mut self, style: crate::TextStyleRefinement, f: F) -> R
549    where
550        F: FnOnce(&mut Self) -> R,
551    {
552        self.window_cx.app.push_text_style(style);
553        let result = f(self);
554        self.window_cx.app.pop_text_style();
555        result
556    }
557
558    fn with_state<T: Send + Sync + 'static, F, R>(&mut self, state: T, f: F) -> R
559    where
560        F: FnOnce(&mut Self) -> R,
561    {
562        self.window_cx.app.push_state(state);
563        let result = f(self);
564        self.window_cx.app.pop_state::<T>();
565        result
566    }
567}
568
569impl<S> BorrowWindow for ViewContext<'_, '_, S> {
570    fn window(&self) -> &Window {
571        &self.window_cx.window
572    }
573
574    fn window_mut(&mut self) -> &mut Window {
575        &mut *self.window_cx.window
576    }
577}
578
579impl<'a, 'w, S: Send + Sync + 'static> ViewContext<'a, 'w, S> {
580    fn mutable(app: &'a mut AppContext, window: &'w mut Window, entity_id: EntityId) -> Self {
581        Self {
582            window_cx: WindowContext::mutable(app, window),
583            entity_id,
584            entity_type: PhantomData,
585        }
586    }
587
588    pub fn handle(&self) -> WeakHandle<S> {
589        self.entities.weak_handle(self.entity_id)
590    }
591
592    pub fn on_next_frame(&mut self, f: impl FnOnce(&mut S, &mut ViewContext<S>) + Send + 'static) {
593        let mut cx = self.to_async();
594        let entity = self.handle();
595        let display_id = self.window.display_id;
596        self.display_linker.on_next_frame(display_id, move |_, _| {
597            entity.update(&mut cx, f).ok();
598        });
599    }
600
601    pub fn observe<E: Send + Sync + 'static>(
602        &mut self,
603        handle: &Handle<E>,
604        on_notify: impl Fn(&mut S, Handle<E>, &mut ViewContext<'_, '_, S>) + Send + Sync + 'static,
605    ) {
606        let this = self.handle();
607        let handle = handle.downgrade();
608        let window_handle = self.window.handle;
609        self.app
610            .observers
611            .entry(handle.id)
612            .or_default()
613            .push(Arc::new(move |cx| {
614                cx.update_window(window_handle.id, |cx| {
615                    if let Some(handle) = handle.upgrade(cx) {
616                        this.update(cx, |this, cx| on_notify(this, handle, cx))
617                            .is_ok()
618                    } else {
619                        false
620                    }
621                })
622                .unwrap_or(false)
623            }));
624    }
625
626    pub fn notify(&mut self) {
627        self.window_cx.notify();
628        self.window_cx
629            .app
630            .pending_effects
631            .push_back(Effect::Notify(self.entity_id));
632    }
633
634    pub fn run_on_main<R>(
635        &mut self,
636        view: &mut S,
637        f: impl FnOnce(&mut S, &mut MainThread<ViewContext<'_, '_, S>>) -> R + Send + 'static,
638    ) -> Task<Result<R>>
639    where
640        R: Send + 'static,
641    {
642        if self.executor.is_main_thread() {
643            let cx = unsafe { mem::transmute::<&mut Self, &mut MainThread<Self>>(self) };
644            Task::ready(Ok(f(view, cx)))
645        } else {
646            let handle = self.handle().upgrade(self).unwrap();
647            self.window_cx.run_on_main(move |cx| handle.update(cx, f))
648        }
649    }
650
651    pub fn spawn<Fut, R>(
652        &mut self,
653        f: impl FnOnce(WeakHandle<S>, AsyncWindowContext) -> Fut + Send + 'static,
654    ) -> Task<R>
655    where
656        R: Send + 'static,
657        Fut: Future<Output = R> + Send + 'static,
658    {
659        let handle = self.handle();
660        self.window_cx.spawn(move |_, cx| {
661            let result = f(handle, cx);
662            async move { result.await }
663        })
664    }
665
666    pub(crate) fn erase_state<R>(&mut self, f: impl FnOnce(&mut ViewContext<()>) -> R) -> R {
667        let entity_id = self.unit_entity.id;
668        let mut cx = ViewContext::mutable(
669            &mut *self.window_cx.app,
670            &mut *self.window_cx.window,
671            entity_id,
672        );
673        f(&mut cx)
674    }
675}
676
677impl<'a, 'w, S> Context for ViewContext<'a, 'w, S> {
678    type EntityContext<'b, 'c, U: 'static + Send + Sync> = ViewContext<'b, 'c, U>;
679    type Result<U> = U;
680
681    fn entity<T2: Send + Sync + 'static>(
682        &mut self,
683        build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T2>) -> T2,
684    ) -> Handle<T2> {
685        self.window_cx.entity(build_entity)
686    }
687
688    fn update_entity<U: Send + Sync + 'static, R>(
689        &mut self,
690        handle: &Handle<U>,
691        update: impl FnOnce(&mut U, &mut Self::EntityContext<'_, '_, U>) -> R,
692    ) -> R {
693        self.window_cx.update_entity(handle, update)
694    }
695}
696
697impl<'a, 'w, S: 'static> std::ops::Deref for ViewContext<'a, 'w, S> {
698    type Target = WindowContext<'a, 'w>;
699
700    fn deref(&self) -> &Self::Target {
701        &self.window_cx
702    }
703}
704
705impl<'a, 'w, S: 'static> std::ops::DerefMut for ViewContext<'a, 'w, S> {
706    fn deref_mut(&mut self) -> &mut Self::Target {
707        &mut self.window_cx
708    }
709}
710
711// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
712slotmap::new_key_type! { pub struct WindowId; }
713
714#[derive(PartialEq, Eq)]
715pub struct WindowHandle<S> {
716    id: WindowId,
717    state_type: PhantomData<S>,
718}
719
720impl<S> Copy for WindowHandle<S> {}
721
722impl<S> Clone for WindowHandle<S> {
723    fn clone(&self) -> Self {
724        WindowHandle {
725            id: self.id,
726            state_type: PhantomData,
727        }
728    }
729}
730
731impl<S> WindowHandle<S> {
732    pub fn new(id: WindowId) -> Self {
733        WindowHandle {
734            id,
735            state_type: PhantomData,
736        }
737    }
738}
739
740impl<S: 'static> Into<AnyWindowHandle> for WindowHandle<S> {
741    fn into(self) -> AnyWindowHandle {
742        AnyWindowHandle {
743            id: self.id,
744            state_type: TypeId::of::<S>(),
745        }
746    }
747}
748
749#[derive(Copy, Clone, PartialEq, Eq)]
750pub struct AnyWindowHandle {
751    pub(crate) id: WindowId,
752    state_type: TypeId,
753}
754
755#[derive(Clone)]
756pub struct Layout {
757    pub order: u32,
758    pub bounds: Bounds<Pixels>,
759}