Files
ragusaitweb/src/components/layout/FancyCursor.tsx
google-labs-jules[bot] d5b079d452 Refactor FancyCursor to use mouseover delegation
- Moves expensive DOM checks (`closest`) and class toggling from `mousemove` loop to `mouseover` handler.
- Removes `document.elementFromPoint` fallback to eliminate layout thrashing.
- Updates tests to verify performance improvements.
- Fixes `Hero.test.tsx` missing jsdom environment.
2026-01-23 09:27:45 +00:00

83 lines
3.8 KiB
TypeScript

import { memo, useEffect, useRef, useState } from 'react';
import './FancyCursor.css';
// This is the new, more performant implementation for the custom cursor.
// It uses requestAnimationFrame for smooth movement and direct DOM manipulation for speed.
export const FancyCursor = memo(() => {
const cursorRef = useRef<HTMLDivElement>(null);
const [isTouch, setIsTouch] = useState(false);
useEffect(() => {
// Check for touch devices once at the beginning. If it's a touch device,
// the custom cursor will not be rendered.
if (typeof window !== 'undefined' && ('ontouchstart' in window || navigator.maxTouchPoints > 0)) {
setIsTouch(true);
return;
}
const cursor = cursorRef.current;
if (!cursor) return;
let animationFrameId: number;
const updateCursorState = (el: Element | null) => {
const classList = cursor.classList;
// Coercing to boolean with `!!` is a micro-optimization.
const isResize = !!el?.closest('#custom-resize-handle');
const isText = !!el?.closest('input[type="text"], input[type="email"], textarea, [contenteditable="true"]');
const isLink = !!el?.closest('a, button, [role="button"], input[type="submit"], input[type="button"]');
// These classes are toggled based on the hovered element.
// The actual visual styles are defined in your CSS files.
classList.toggle('resize-hover', isResize);
classList.toggle('text-hover', isText && !isResize);
classList.toggle('link-hover', isLink && !isText && !isResize);
};
const handleMouseOver = (e: MouseEvent) => {
updateCursorState(e.target as Element);
};
// The mouse move handler is throttled with requestAnimationFrame to ensure
// the animation is smooth and doesn't cause performance issues.
const handleMouseMove = (e: MouseEvent) => {
cancelAnimationFrame(animationFrameId);
animationFrameId = requestAnimationFrame(() => {
// The offset issue was caused by positioning the cursor's top-left corner
// at the mouse coordinates. To fix this, `translate(-50%, -50%)` is added.
// This shifts the cursor element by half its own width and height,
// which effectively centers it on the pointer without affecting the visuals.
cursor.style.transform = `translate3d(${e.clientX}px, ${e.clientY}px, 0) translate(-50%, -50%)`;
});
};
// Using a passive event listener can improve scrolling performance.
window.addEventListener('mousemove', handleMouseMove, { passive: true });
window.addEventListener('mouseover', handleMouseOver, { passive: true });
// The cleanup function removes the event listener when the component unmounts
// to prevent memory leaks.
return () => {
window.removeEventListener('mousemove', handleMouseMove);
window.removeEventListener('mouseover', handleMouseOver);
cancelAnimationFrame(animationFrameId);
};
}, []); // The empty dependency array ensures this effect runs only once.
if (isTouch) {
return null;
}
return (
// `will-change` is a hint to the browser to optimize for transform changes.
<div ref={cursorRef} id="fancy-cursor" style={{ willChange: 'transform' }}>
<div className="fancy-cursor-dot" />
{/* SVG updated to use currentColor to inherit from CSS */}
<svg viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
<path d="M5 19L19 5M5 19L9 19M5 19L5 15M19 5L15 5M19 5L19 9" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"/>
</svg>
</div>
);
});