jiang/index.html at main · MegaCorn/jiang · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>OneShot View Demo</title>
    <script src="https://cdn.tailwindcss.com"></script>
    <style>
        /* Essential CSS for View Transitions
           This enables the custom 'hero-image' transition name we will use dynamically.
        */
        ::view-transition-old(hero-image),
        ::view-transition-new(hero-image) {
            /* Prevent default cross-fade for the image, forcing a pure geometry morph */
            animation: none;
            mix-blend-mode: normal;
        }

        /* Standard fade for other elements (text, etc) */
        ::view-transition-old(root),
        ::view-transition-new(root) {
            animation-duration: 0.4s;
        }

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background-color: #f3f4f6;
            overflow-y: scroll; /* Prevent layout shift when scrollbar appears/disappears */
        }

        /* Utilities for text truncation */
        .line-clamp-2 {
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }

        /* Note: Removed 'scroll-behavior: smooth' to ensure accurate scroll restoration during transitions */
    </style>
</head>
<body class="antialiased text-gray-800">

    <div id="app" class="min-h-screen">
        <!-- Content injected by JavaScript -->
    </div>

    <script>
        // --- Configuration & State ---
        const CONFIG = {
            TOTAL_ITEMS: 30 // Fixed total of 30 items
        };

        const state = {
            view: 'list', // 'list' or 'detail'
            items: [],
            selectedId: null,
            scrollPosition: 0,
            nextId: 1
        };

        // --- Mock Data Generator ---
        function generateItems(count) {
            const newItems = [];
            // Fixed image URL for all cards
            const fixedImage = "https://images.unsplash.com/photo-1472214103451-9374bd1c798e?ixlib=rb-4.0.3&auto=format&fit=crop&w=1000&q=80";

            for (let i = 0; i < count; i++) {
                const id = state.nextId++;
                newItems.push({
                    id: id,
                    title: `Beautiful Destination #${id}`,
                    description: `Experience the serenity of nature in location #${id}. This card demonstrates a seamless transition.`,
                    image: fixedImage,
                    fullText: `This is the detailed content for Destination #${id}. \n\nThe View Transition API allows us to create seamless animations between DOM states. Notice how the image morphed from its grid position to this full-width header? That wasn't a transform animation on top of the page; strictly speaking, the browser took a snapshot of the old state and the new state, and interpolated the geometry of the element we tagged with 'view-transition-name'.\n\nLorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.`
                });
            }
            return newItems;
        }

        // Initialize with exactly 30 items
        state.items = generateItems(CONFIG.TOTAL_ITEMS);

        // --- Render Functions ---

        const app = document.getElementById('app');

        function render() {
            if (state.view === 'list') {
                renderList();
            } else {
                renderDetail();
            }
        }

        function renderList() {
            const gridHtml = state.items.map(item => `
                <div
                    class="card bg-white rounded-xl shadow-md overflow-hidden cursor-pointer hover:shadow-xl transition-shadow duration-300 flex flex-col h-full"
                    onclick="handleCardClick(${item.id})"
                >
                    <div class="relative overflow-hidden h-48 w-full bg-gray-200">
                        <img
                            id="img-${item.id}"
                            src="${item.image}"
                            alt="${item.title}"
                            class="w-full h-full object-cover"
                            loading="lazy"
                        >
                    </div>
                    <div class="p-4 flex-1 flex flex-col">
                        <h3 class="text-lg font-bold mb-2 text-gray-900">${item.title}</h3>
                        <p class="text-gray-600 text-sm line-clamp-2">${item.description}</p>
                    </div>
                </div>
            `).join('');

            app.innerHTML = `
                <header class="bg-white shadow-sm sticky top-0 z-10">
                    <div class="max-w-4xl mx-auto px-4 py-4 flex justify-between items-center">
                        <h1 class="text-xl font-bold text-indigo-600">OneShot View Gallery</h1>
                        <span class="text-xs text-gray-400">${state.items.length} Items</span>
                    </div>
                </header>
                <main class="max-w-4xl mx-auto px-4 py-6">
                    <div id="grid-container" class="grid grid-cols-1 sm:grid-cols-2 gap-6 pb-10">
                        ${gridHtml}
                    </div>
                </main>
            `;

            // Restore scroll position INSTANTLY to ensure View Transition captures the correct frame
            window.scrollTo({
                top: state.scrollPosition,
                behavior: 'instant'
            });
        }

        function renderDetail() {
            const item = state.items.find(i => i.id === state.selectedId);
            if (!item) return;

            app.innerHTML = `
                <div class="bg-white min-h-screen">
                    <div class="relative w-full h-[50vh] bg-gray-900">
                        <img
                            src="${item.image}"
                            class="w-full h-full object-cover"
                            style="view-transition-name: hero-image"
                            alt="${item.title}"
                        >
                        <button
                            onclick="handleBackClick()"
                            class="absolute top-4 left-4 bg-black/50 hover:bg-black/70 text-white rounded-full p-2 backdrop-blur-sm transition-colors z-20 flex items-center gap-2 pr-4"
                        >
                            <svg xmlns="http://www.w3.org/2000/svg" class="h-6 w-6" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M10 19l-7-7m0 0l7-7m-7 7h18" />
                            </svg>
                            <span>Back</span>
                        </button>
                        <div class="absolute bottom-0 left-0 w-full bg-gradient-to-t from-black/80 to-transparent p-6 pt-20">
                            <h1 class="text-3xl md:text-4xl font-bold text-white shadow-black drop-shadow-md">${item.title}</h1>
                        </div>
                    </div>

                    <main class="max-w-3xl mx-auto px-6 py-10 animate-fade-in-up">
                        <div class="prose prose-lg text-gray-700">
                            <p class="text-xl font-medium text-indigo-600 mb-6">${item.description}</p>
                            ${item.fullText.split('\n\n').map(para => `<p class="mb-4 leading-relaxed">${para}</p>`).join('')}
                            <div class="h-64 bg-gray-100 rounded-lg mt-8 flex items-center justify-center text-gray-400">
                                Additional Content Area
                            </div>
                        </div>
                    </main>
                </div>
            `;

            // Scroll to top INSTANTLY for the new detail page
            window.scrollTo({
                top: 0,
                behavior: 'instant'
            });
        }

        // --- Interaction Handlers ---

        window.handleCardClick = async (id) => {
            // 1. Save Scroll Position before transition starts
            state.scrollPosition = window.scrollY;
            state.selectedId = id;

            // 2. Prepare Transition
            const clickedImg = document.getElementById(`img-${id}`);
            if (clickedImg) {
                clickedImg.style.viewTransitionName = 'hero-image';
            }

            // 3. Execute Transition
            if (document.startViewTransition) {
                const transition = document.startViewTransition(() => {
                    state.view = 'detail';
                    render();
                });

                try {
                    await transition.finished;
                } finally {
                    // Cleanup
                }
            } else {
                state.view = 'detail';
                render();
            }
        };

        window.handleBackClick = async () => {
             if (!document.startViewTransition) {
                state.view = 'list';
                render();
                return;
            }

            const transition = document.startViewTransition(() => {
                state.view = 'list';
                render();

                // Note: The renderList() function handles the scrolling to state.scrollPosition.
                // It is critical this happens synchronously here so the 'new' snapshot is correct.

                const targetImg = document.getElementById(`img-${state.selectedId}`);
                if (targetImg) {
                    targetImg.style.viewTransitionName = 'hero-image';
                }
            });

            await transition.finished;

            // Cleanup after animation is done
            const targetImg = document.getElementById(`img-${state.selectedId}`);
            if (targetImg) {
                targetImg.style.viewTransitionName = '';
            }
        };

        // --- Init ---
        render();

    </script>
</body>

</html>