feat: add onChange callback to useWindowSize

Author: mahmoud-elgammal

src/useWindowSize.ts

@@ -3,44 +3,52 @@ import { useEffect } from 'react';
 import useRafState from './useRafState';
 import { isBrowser, off, on } from './misc/util';
 
+// Define the type for options that can be passed to the hook
 interface Options {
-  initialWidth?: number;
-  initialHeight?: number;
-  onChange?: (width: number, height: number) => void;
+  initialWidth?: number; // Initial width of the window (Default value is Infinity)
+  initialHeight?: number; // Initial height of the window (Default value is Infinity)
+  onChange?: (width: number, height: number) => void; // Callback function to execute on window resize (optional)
 }
 
 const useWindowSize = ({
   initialWidth = Infinity,
   initialHeight = Infinity,
   onChange,
 }: Options = {}) => {
+  // Use the useRafState hook to maintain the current window size (width and height)
   const [state, setState] = useRafState<{ width: number; height: number }>({
     width: isBrowser ? window.innerWidth : initialWidth,
     height: isBrowser ? window.innerHeight : initialHeight,
   });
 
   useEffect((): (() => void) | void => {
+    // Only run the effect on the browser (to avoid issues with SSR)
     if (isBrowser) {
       const handler = () => {
         const width = window.innerWidth;
         const height = window.innerHeight;
 
+        // Update the state with the new window size
         setState({
-          width: window.innerWidth,
-          height: window.innerHeight,
+          width,
+          height,
         });
 
+        // If an onChange callback is provided, call it with the new dimensions
         if (onChange) onChange(width, height);
       };
 
+      // Add event listener for the resize event
       on(window, 'resize', handler);
 
+      // Cleanup function to remove the event listener when the component is unmounted (it's for performance optimization)
       return () => {
         off(window, 'resize', handler);
       };
     }
   }, []);
 
+  // Return the current window size (width and height)
   return state;
 };
 

stories/useWindowSize.story.tsx

@@ -1,10 +1,14 @@
 import { storiesOf } from '@storybook/react';
 import * as React from 'react';
 import { useWindowSize } from '../src';
+import { action } from '@storybook/addon-actions'; // Import addon-actions
 import ShowDocs from './util/ShowDocs';
 
 const Demo = () => {
-  const { width, height } = useWindowSize();
+  const { width, height } = useWindowSize({
+    // Log the resize event to the Storybook actions panel
+    onChange: action('window resize'),
+  });
 
   return (
     <div>