Twitter Endless Scroll [X]

Endless scrolling between image posts with mousewheel

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Twitter Endless Scroll [X]
// @namespace    Twitter
// @version      1.7
// @description  Endless scrolling between image posts with mousewheel
// @author       NightLancerX
// @match        https://x.com/*
// @match        https://twitter.com/*
// @match        https://mobile.twitter.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=twitter.com
// @license      CC-BY-NC-SA
// @grant        none
// @require      https://code.jquery.com/jquery-3.3.1.min.js
// @run-at       document-end
// @noframes
// ==/UserScript==

(function() {
	'use strict';
	const DEBUG = false;

	let nextPost, shifted = false, lastIndex = 0, img_src;
	let img = new Image();
	let block_selector = 'article'
	let content_selector = 'img[src*="https://pbs.twimg.com/media/"]'; //, img[src*="pbs.twimg.com/tweet_video_thumb/"]';//, img[src*="pbs.twimg.com/amplify_video_thumb/"]';
	let offset_selector = '[data-testid="cellInnerDiv"]'

	function changePost(shift, useFirst = true){
		let posts = [...document.querySelectorAll(`${block_selector}:has(${content_selector})`)];
		if (DEBUG) console.log(posts);
		let index = posts.indexOf(document.querySelector(`${block_selector}:has([href='${location.pathname}'])`));
		if (DEBUG) console.log(`lastIndex: ${lastIndex}`);
		if (DEBUG) console.log(`index: ${index}`);
		if (index<0){ //needed anymore?
			index = lastIndex;
		}

		nextPost = posts[index+shift];
		if (DEBUG) console.log(nextPost);

		if (nextPost){
			nextPost.scrollIntoView();
			let elements = nextPost.querySelectorAll(content_selector);
			((elements.length==1 || useFirst) ? elements[0] : elements[elements.length - 1])?.click();
			//nextPost.querySelector(content_selector)?.click();
			shifted = true;
			lastIndex = index+shift;
			//pre-cache
			// img_src = posts[index+shift*2]?.querySelector(content_selector)?.src;
			// if (DEBUG) console.log(`pre img_src: ${img_src}`); //absolutely random and chaotic
			//findValidImage(img_src, ["large", "4096x4096"]);
		}
	}

// 	async function findValidImage(img_src, qualityList) {
// 		const prefix = img_src.split("name=")[0];
// 		let i = 0;

// 		function checkImage(url) {
// 			return new Promise(resolve => {
// 				const img = new Image();
// 				img.onload = () => resolve(true);
// 				img.onerror = () => {
// 					if (DEBUG) console.log(`img.onerror`);
// 					resolve(false);
// 				}
// 				img.src = url;
// 			});
// 		}

// 		for (let name of qualityList) {
// 			const testUrl = prefix + "name=" + name;
// 			const isValid = await checkImage(testUrl);
// 			if (isValid) {
// 				if (DEBUG) console.log(`img_src: ${testUrl}`);
// 				return testUrl;
// 			}
// 		}
// 	}

	function image_count(){
		return document.querySelectorAll(`${block_selector} [href*='${location.pathname.replace(/\/\d+$/, "")}']`)?.length ?? 0
	}

	$('body').on('wheel', '[aria-labelledby="modal-header"]', function(e){
		e.preventDefault();
		e.stopPropagation();

		let left;
		if (e.originalEvent.deltaY < 0){
			if ((left = document.querySelector('[data-testid="Carousel-NavLeft"]')) && image_count() > 1){
				left.click();
			}
			else
				changePost(-1, false);
		}

		let right;
		if (e.originalEvent.deltaY > 0){
			if ((right = document.querySelector('[data-testid="Carousel-NavRight"]')) && image_count() > 1){
				right.click();
			}
			else
				changePost(+1);
		}
	});

	$('body').on('click', '[aria-labelledby="modal-header"] [data-testid="swipe-to-dismiss"]', function(e){
		if (shifted) setTimeout(()=>{
			let offset = nextPost?.closest(`${offset_selector}`).style.transform.match(/\d+/)?.[0];
			window.scroll(0, offset);
			shifted = false;
		}, 500);
	})
})();