Professional Lazy Loading

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Professional Lazy Loading</title>
    <style>
        body {
            font-family: 'Arial', sans-serif;
            background: linear-gradient(135deg, #ff758c, #ff7eb3);
            color: #333;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            min-height: 100vh;
            margin: 0;
        }
        h1 {
            margin-bottom: 20px;
            font-size: 2.5em;
            color: #fff;
        }
        .gallery {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 20px;
            width: 90%;
            max-width: 1200px;
        }
        .gallery img {
            width: 100%;
            border-radius: 15px;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
            transition: transform 0.3s, opacity 0.3s;
            opacity: 0;
            transform: scale(0.95);
        }
        .gallery img.lazyloaded {
            opacity: 1;
            transform: scale(1);
        }
        .gallery img.loading-icon {
            content: url('https://example.com/loading-icon.png');
            display: block;
            margin: 0 auto;
        }
        .loader {
            display: flex;
            align-items: center;
            justify-content: center;
            width: 100%;
            height: 100vh;
            background: rgba(255, 255, 255, 0.8);
            position: fixed;
            top: 0;
            left: 0;
            z-index: 10;
        }
        .loader img {
            width: 100px;
            animation: spin 1.5s linear infinite;
        }
        @keyframes spin {
            from { transform: rotate(0deg); }
            to { transform: rotate(360deg); }
        }
    </style>
</head>
<body>
<h1>Professional Lazy Loading Gallery 🚀</h1>
<div class="gallery">
    <img data-src="https://via.placeholder.com/600x400" alt="Image 1" class="loading-icon">
    <img data-src="https://via.placeholder.com/600x400" alt="Image 2" class="loading-icon">
    <img data-src="https://via.placeholder.com/600x400" alt="Image 3" class="loading-icon">
    <img data-src="https://via.placeholder.com/600x400" alt="Image 4" class="loading-icon">
    <img data-src="https://via.placeholder.com/600x400" alt="Image 5" class="loading-icon">
    <img data-src="https://via.placeholder.com/600x400" alt="Image 6" class="loading-icon">
</div>
<div class="loader">
    <img src="https://example.com/spinner-icon.png" alt="Loading...">
</div>
<script>
    document.addEventListener('DOMContentLoaded', function () {
        const loader = document.querySelector('.loader');
        loader.style.display = 'none';
        const lazyLoadImages = () => {
            const images = document.querySelectorAll('.gallery img');
            images.forEach(image => {
                const imageSrc = image.getAttribute('data-src');
                if (imageSrc) {
                    image.src = imageSrc;
                    image.onload = () => {
                        image.classList.remove('loading-icon');
                        image.classList.add('lazyloaded');
                    }
                }
            });
        };
        let lazyLoadThrottleTimeout;
        const lazyLoad = () => {
            if (lazyLoadThrottleTimeout) {
                clearTimeout(lazyLoadThrottleTimeout);
            }
            lazyLoadThrottleTimeout = setTimeout(() => {
                const scrollTop = window.pageYOffset;
                const images = document.querySelectorAll('.gallery img');
                images.forEach(image => {
                    if (image.offsetTop < (window.innerHeight + scrollTop)) {
                        image.src = image.dataset.src;
                        image.onload = () => {
                            image.classList.remove('loading-icon');
                            image.classList.add('lazyloaded');
                        }
                    }
                });
                if (images.length === 0) {
                    document.removeEventListener('scroll', lazyLoad);
                    window.removeEventListener('resize', lazyLoad);
                    window.removeEventListener('orientationChange', lazyLoad);
                }
            }, 20);
        };
        document.addEventListener('scroll', lazyLoad);
        window.addEventListener('resize', lazyLoad);
        window.addEventListener('orientationChange', lazyLoad);
        lazyLoad();
    });
</script>
</body>
</html>

Professional Lazy Loading - MeggiTools