☰

Pixel-Precision Wheel Scroll

Add pixel-precision wheel scrolling capability using CTRL+SHIFT+Wheel for vertical scroll, and CTRL+ALT+Wheel for horizontal scroll, for any scrollable element which can be scrolled at pixel level.

  1. // ==UserScript==
  2. // @name         Pixel-Precision Wheel Scroll
  3. // @namespace    https://greasyfork.org/en/users/85671-jcunews
  4. // @version      1.0.3
  5. // @license      AGPL v3
  6. // @author       jcunews
  7. // @description  Add pixel-precision wheel scrolling capability using CTRL+SHIFT+Wheel for vertical scroll, and CTRL+ALT+Wheel for horizontal scroll, for any scrollable element which can be scrolled at pixel level.
  8. // @match        *://*/*
  9. // @grant        none
  10. // @run-at       document-start
  11. // ==/UserScript==
  12.  
  13. addEventListener("wheel", (ev, ele) => {
  14.   if (ev.ctrlKey) {
  15.     ele = ev.target;
  16.     while (ele && (ele.offsetWidth === ele.scrollWidth) && (ele.offsetHeight === ele.scrollHeight)) ele = ele.parentNode;
  17.     ele = ele || window;
  18.     if (ev.shiftKey && !ev.altKey) {
  19.       ele.scrollBy(0, ev.deltaY > 0 ? 1 : -1);
  20.       ev.stopPropagation();
  21.       ev.preventDefault()
  22.     } else if (ev.altKey && !ev.shiftKey) {
  23.       ele.scrollBy(ev.deltaY > 0 ? 1 : -1, 0);;
  24.       ev.stopPropagation();
  25.       ev.preventDefault()
  26.     }
  27.   }
  28. }, {capture: true, passive: false})