refactor: packages/

1 files changed, 61 insertions, 0 deletions

diff --git a/packages/excalidraw/reactUtils.ts b/packages/excalidraw/reactUtils.ts
new file mode 100644
index 0000000..535302d
--- /dev/null
+++ b/packages/excalidraw/reactUtils.ts
@@ -0,0 +1,61 @@
+/**
+ * @param func handler taking at most single parameter (event).
+ */
+
+import { unstable_batchedUpdates } from "react-dom";
+import { version as ReactVersion } from "react";
+import { throttleRAF } from "./utils";
+
+export const withBatchedUpdates = <
+  TFunction extends ((event: any) => void) | (() => void),
+>(
+  func: Parameters<TFunction>["length"] extends 0 | 1 ? TFunction : never,
+) =>
+  ((event) => {
+    unstable_batchedUpdates(func as TFunction, event);
+  }) as TFunction;
+
+/**
+ * barches React state updates and throttles the calls to a single call per
+ * animation frame
+ */
+export const withBatchedUpdatesThrottled = <
+  TFunction extends ((event: any) => void) | (() => void),
+>(
+  func: Parameters<TFunction>["length"] extends 0 | 1 ? TFunction : never,
+) => {
+  // @ts-ignore
+  return throttleRAF<Parameters<TFunction>>(((event) => {
+    unstable_batchedUpdates(func, event);
+  }) as TFunction);
+};
+
+export const isRenderThrottlingEnabled = (() => {
+  // we don't want to throttle in react < 18 because of #5439 and it was
+  // getting more complex to maintain the fix
+  let IS_REACT_18_AND_UP: boolean;
+  try {
+    const version = ReactVersion.split(".");
+    IS_REACT_18_AND_UP = Number(version[0]) > 17;
+  } catch {
+    IS_REACT_18_AND_UP = false;
+  }
+
+  let hasWarned = false;
+
+  return () => {
+    if (window.EXCALIDRAW_THROTTLE_RENDER === true) {
+      if (!IS_REACT_18_AND_UP) {
+        if (!hasWarned) {
+          hasWarned = true;
+          console.warn(
+            "Excalidraw: render throttling is disabled on React versions < 18.",
+          );
+        }
+        return false;
+      }
+      return true;
+    }
+    return false;
+  };
+})();