Add animation frame notifier

Cargo.toml

@@ -29,4 +29,5 @@ raw-window-handle = { version = "0.5.2", optional = true }
 skia-safe = { version = "0.64.0", features = ["gl"], optional = true }
 winit = { version = "0.28.6", optional = true }
 interpolation = "0.3.0"
+tokio = { version = "1.32.0", features = ["full"] }
 

examples/animation.rs

@@ -1,7 +1,4 @@
-use std::{
-    thread::{self, sleep},
-    time::{Duration, Instant},
-};
+use std::time::Instant;
 
 use skia_safe::Color4f;
 use taffy::{
@@ -10,7 +7,8 @@ use taffy::{
 };
 use viewbuilder::{render::UserEvent, Element, Renderer, Tree};
 
-fn main() {
+#[tokio::main]
+async fn main() {
     // TODO this is really early stage, an animation frame should be requested
 
     let mut tree = Tree::default();
@@ -23,8 +21,9 @@ fn main() {
 
     let renderer = Renderer::new();
     let tx = renderer.tx.clone();
+    let notify = renderer.notify.clone();
 
-    thread::spawn(move || {
+    tokio::spawn(async move {
         let start = Instant::now();
         loop {
             let t = (Instant::now() - start).as_millis() as f32;
@@ -36,7 +35,7 @@ fn main() {
             })))
             .unwrap();
 
-            sleep(Duration::from_millis(5))
+            notify.notified().await;
         }
     });
 

src/render.rs

@@ -20,8 +20,10 @@ use slotmap::DefaultKey;
 use std::{
     ffi::CString,
     num::NonZeroU32,
-    time::{Duration, Instant}, sync::mpsc,
+    sync::{mpsc, Arc},
+    time::{Duration, Instant},
 };
+use tokio::sync::Notify;
 use winit::{
     event::{ElementState, Event, KeyboardInput, VirtualKeyCode, WindowEvent},
     event_loop::{ControlFlow, EventLoop, EventLoopBuilder},
@@ -48,6 +50,7 @@ pub struct Renderer {
     fb_info: FramebufferInfo,
     pub tx: mpsc::Sender<UserEvent>,
     rx: mpsc::Receiver<UserEvent>,
+    pub notify: Arc<Notify>,
 }
 
 impl Renderer {
@@ -172,6 +175,7 @@ impl Renderer {
             fb_info,
             tx,
             rx,
+            notify: Arc::new(Notify::default()),
         }
     }
 
@@ -322,6 +326,8 @@ impl Renderer {
                 previous_frame_start = frame_start;
             }
             if draw_frame {
+                self.notify.notify_waiters();
+
                 let canvas = self.surface.canvas();
                 canvas.clear(Color::WHITE);