initial commit: scaffolding

1 files changed, 44 insertions, 0 deletions

diff --git a/node_modules/rxjs/src/internal/scheduler/animationFrameProvider.ts b/node_modules/rxjs/src/internal/scheduler/animationFrameProvider.ts
new file mode 100644
index 0000000..610093b
--- /dev/null
+++ b/node_modules/rxjs/src/internal/scheduler/animationFrameProvider.ts
@@ -0,0 +1,44 @@
+import { Subscription } from '../Subscription';
+
+interface AnimationFrameProvider {
+  schedule(callback: FrameRequestCallback): Subscription;
+  requestAnimationFrame: typeof requestAnimationFrame;
+  cancelAnimationFrame: typeof cancelAnimationFrame;
+  delegate:
+    | {
+        requestAnimationFrame: typeof requestAnimationFrame;
+        cancelAnimationFrame: typeof cancelAnimationFrame;
+      }
+    | undefined;
+}
+
+export const animationFrameProvider: AnimationFrameProvider = {
+  // When accessing the delegate, use the variable rather than `this` so that
+  // the functions can be called without being bound to the provider.
+  schedule(callback) {
+    let request = requestAnimationFrame;
+    let cancel: typeof cancelAnimationFrame | undefined = cancelAnimationFrame;
+    const { delegate } = animationFrameProvider;
+    if (delegate) {
+      request = delegate.requestAnimationFrame;
+      cancel = delegate.cancelAnimationFrame;
+    }
+    const handle = request((timestamp) => {
+      // Clear the cancel function. The request has been fulfilled, so
+      // attempting to cancel the request upon unsubscription would be
+      // pointless.
+      cancel = undefined;
+      callback(timestamp);
+    });
+    return new Subscription(() => cancel?.(handle));
+  },
+  requestAnimationFrame(...args) {
+    const { delegate } = animationFrameProvider;
+    return (delegate?.requestAnimationFrame || requestAnimationFrame)(...args);
+  },
+  cancelAnimationFrame(...args) {
+    const { delegate } = animationFrameProvider;
+    return (delegate?.cancelAnimationFrame || cancelAnimationFrame)(...args);
+  },
+  delegate: undefined,
+};