View nhentai galleries in a vertical scroll instead of clicking page by page
// ==UserScript==
// @name nhentai Vertical Scroll
// @namespace https://nhentai.net
// @version 1.4
// @author JoyArz
// @description View nhentai galleries in a vertical scroll instead of clicking page by page
// @match https://nhentai.net/g/*/
// @grant none
// @run-at document-idle
// ==/UserScript==
(function() {
'use strict';
const STYLE = `
body {
background: #0f0f14 !important;
}
#content {
background: #0f0f14 !important;
}
.vs-container {
position: relative;
width: 100%;
max-width: 100vw;
margin: 0 auto;
padding-top: 20px;
}
.vs-page {
position: relative;
width: 100%;
display: flex;
justify-content: center;
background: #0f0f14;
margin-bottom: 8px;
min-height: 100px;
}
.vs-page img {
max-width: 100%;
max-height: 100vh;
object-fit: contain;
display: block;
}
.vs-page img.loading {
opacity: 0.3;
}
.vs-loading {
position: fixed;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
background: rgba(0, 0, 0, 0.9);
color: white;
padding: 20px 40px;
border-radius: 10px;
font-family: sans-serif;
font-size: 16px;
z-index: 9999;
text-align: center;
}
.vs-nav {
position: fixed;
bottom: 20px;
right: 20px;
display: flex;
flex-direction: column;
gap: 10px;
z-index: 9998;
}
.vs-nav button {
width: 50px;
height: 50px;
border-radius: 50%;
border: none;
background: #ff3366;
color: white;
font-size: 20px;
cursor: pointer;
opacity: 0.8;
transition: opacity 0.2s, transform 0.2s;
}
.vs-nav button:hover {
opacity: 1;
transform: scale(1.1);
}
.vs-nav-top {
position: fixed;
top: 20px;
right: 20px;
z-index: 9998;
}
.vs-nav-top button {
padding: 10px 20px;
border-radius: 20px;
border: none;
background: #ff3366;
color: white;
font-size: 14px;
cursor: pointer;
opacity: 0.8;
transition: opacity 0.2s;
}
.vs-nav-top button:hover {
opacity: 1;
}
.vs-error {
color: #ff3366;
padding: 20px;
text-align: center;
}
.hidden { display: none !important; }
`;
const NAV_HTML = `
<div class="vs-nav">
<button id="vs-scroll-top" title="Scroll to top">▲</button>
<button id="vs-scroll-bottom" title="Scroll to bottom">▼</button>
</div>
<div class="vs-nav-top">
<button id="vs-toggle-zoom">Zoom: 1.0x</button>
</div>
`;
class NHentaiVerticalScroll {
constructor() {
this.galleryId = null;
this.pages = 0;
this.currentZoom = 1.0;
this.container = null;
this.loadedPages = new Set();
this.loadedCount = 0;
this.initialized = false;
}
extractGalleryInfo() {
const thumbs = document.querySelectorAll('#thumbnail-container .thumb-container');
if (thumbs.length > 0) {
this.pages = thumbs.length;
const firstThumb = thumbs[0].querySelector('img');
if (firstThumb) {
const srcMatch = firstThumb.src.match(/\/galleries\/(\d+)\//);
if (srcMatch) {
this.galleryId = srcMatch[1];
}
}
}
if (!this.galleryId) {
const coverImg = document.querySelector('#cover img');
if (coverImg) {
const srcMatch = coverImg.src.match(/\/galleries\/(\d+)\//);
if (srcMatch) {
this.galleryId = srcMatch[1];
}
}
}
console.log('NHentai VS:', { galleryId: this.galleryId, pages: this.pages });
}
getImageUrl(pageNum) {
const servers = ['i1', 'i2', 'i3', 'i4'];
const server = servers[(pageNum - 1) % 4];
return `https://${server}.nhentai.net/galleries/${this.galleryId}/${pageNum}.webp`;
}
init() {
if (this.initialized) return;
this.initialized = true;
this.extractGalleryInfo();
if (!this.galleryId || !this.pages) {
this.showError('Could not detect gallery info');
return;
}
this.injectStyles();
this.createVerticalView();
this.addNavigation();
this.setupKeyboardNav();
this.loadVisiblePages();
}
showError(msg) {
const errorDiv = document.createElement('div');
errorDiv.className = 'vs-error';
errorDiv.textContent = msg;
const content = document.querySelector('#content');
if (content) {
content.innerHTML = '';
content.appendChild(errorDiv);
}
}
injectStyles() {
const styleEl = document.createElement('style');
styleEl.id = 'vs-styles';
styleEl.textContent = STYLE;
document.head.appendChild(styleEl);
}
createVerticalView() {
const thumbnailContainer = document.querySelector('#thumbnail-container');
if (thumbnailContainer) {
thumbnailContainer.classList.add('hidden');
}
this.container = document.createElement('div');
this.container.className = 'vs-container';
for (let i = 1; i <= this.pages; i++) {
const pageEl = document.createElement('div');
pageEl.className = 'vs-page';
pageEl.dataset.page = i;
pageEl.innerHTML = `<img class="loading" data-src="${this.getImageUrl(i)}" alt="Page ${i}">`;
this.container.appendChild(pageEl);
}
const bigcontainer = document.querySelector('#bigcontainer');
const relatedContainer = document.querySelector('#related-container');
const commentPostContainer = document.querySelector('#comment-post-container');
const commentContainer = document.querySelector('#comment-container');
if (relatedContainer && relatedContainer.parentNode) {
relatedContainer.parentNode.insertBefore(this.container, relatedContainer);
} else if (commentPostContainer && commentPostContainer.parentNode) {
commentPostContainer.parentNode.insertBefore(this.container, commentPostContainer);
} else if (commentContainer && commentContainer.parentNode) {
commentContainer.parentNode.insertBefore(this.container, commentContainer);
} else {
const content = document.querySelector('#content');
if (content) {
content.appendChild(this.container);
}
}
const loading = document.createElement('div');
loading.className = 'vs-loading';
loading.id = 'vs-loading';
loading.textContent = `Loading...`;
document.body.appendChild(loading);
setTimeout(() => {
this.loadInitialBatch();
}, 500);
}
loadInitialBatch() {
const loading = document.getElementById('vs-loading');
const pages = Array.from(this.container.querySelectorAll('.vs-page'));
const batchSize = 10;
let loaded = 0;
const toLoad = pages.slice(0, Math.min(batchSize, this.pages));
toLoad.forEach((pageEl) => {
const img = pageEl.querySelector('img');
const pageNum = parseInt(pageEl.dataset.page, 10);
img.onload = () => {
img.classList.remove('loading');
this.loadedPages.add(pageNum);
this.loadedCount++;
loaded++;
if (loading) loading.textContent = `Loaded ${this.loadedCount}/${this.pages}`;
if (loaded >= toLoad.length) {
setTimeout(() => { if (loading) loading.classList.add('hidden'); }, 300);
}
};
img.onerror = () => {
img.classList.remove('loading');
img.alt = `Failed page ${pageNum}`;
this.loadedPages.add(pageNum);
this.loadedCount++;
loaded++;
if (loaded >= toLoad.length) {
setTimeout(() => { if (loading) loading.classList.add('hidden'); }, 300);
}
};
img.src = img.dataset.src;
});
}
loadVisiblePages() {
if (!this.container) return;
const viewportHeight = window.innerHeight;
const scrollY = window.scrollY;
const pages = Array.from(this.container.querySelectorAll('.vs-page'));
const currentPage = Math.floor((scrollY + viewportHeight) / viewportHeight);
pages.forEach(pageEl => {
const pageNum = parseInt(pageEl.dataset.page, 10);
if (this.loadedPages.has(pageNum)) return;
if (pageNum <= currentPage + 3) {
const img = pageEl.querySelector('img');
if (img && img.dataset.src) {
img.src = img.dataset.src;
this.loadedPages.add(pageNum);
img.onload = () => img.classList.remove('loading');
img.onerror = () => {
img.classList.remove('loading');
img.alt = `Failed page ${pageNum}`;
};
}
}
});
}
addNavigation() {
const navDiv = document.createElement('div');
navDiv.innerHTML = NAV_HTML;
document.body.appendChild(navDiv);
document.getElementById('vs-scroll-top').addEventListener('click', () => {
window.scrollTo({ top: 0, behavior: 'smooth' });
});
document.getElementById('vs-scroll-bottom').addEventListener('click', () => {
window.scrollTo({ top: document.body.scrollHeight, behavior: 'smooth' });
});
document.getElementById('vs-toggle-zoom').addEventListener('click', (e) => {
this.toggleZoom(e.target);
});
}
toggleZoom(btn) {
this.currentZoom = this.currentZoom === 1.0 ? 1.5 : 1.0;
document.querySelectorAll('.vs-page img').forEach(img => {
img.style.maxHeight = `${100 * this.currentZoom}vh`;
});
if (btn) btn.textContent = `Zoom: ${this.currentZoom}x`;
}
setupKeyboardNav() {
window.addEventListener('scroll', () => {
this.loadVisiblePages();
}, { passive: true });
setInterval(() => {
this.loadVisiblePages();
}, 500);
}
}
function initScript() {
if (document.querySelector('#vs-styles')) return;
const vs = new NHentaiVerticalScroll();
const observer = new MutationObserver((mutations) => {
let shouldInit = false;
for (const mutation of mutations) {
if (mutation.type === 'childList' && mutation.addedNodes.length > 0) {
for (const node of mutation.addedNodes) {
if (node.nodeName === 'SECTION' || node.nodeName === 'DIV') {
if (node.id === 'thumbnail-container' || node.querySelector?.('#thumbnail-container')) {
shouldInit = true;
break;
}
}
}
}
}
if (shouldInit && !vs.initialized) {
setTimeout(() => vs.init(), 100);
}
});
observer.observe(document.body, { childList: true, subtree: true });
setTimeout(() => {
const content = document.querySelector('#content');
const thumbnailContainer = document.querySelector('#thumbnail-container');
if (content && thumbnailContainer && !vs.initialized) {
vs.init();
}
}, 2000);
}
if (document.readyState === 'loading') {
document.addEventListener('DOMContentLoaded', initScript);
} else {
initScript();
}
})();