Better titles for FFmpeg doxygen

userscript.js

// ==UserScript==
// @name        Better titles for FFmpeg doxygen
// @namespace   Violentmonkey Scripts
// @match       https://ffmpeg.org/doxygen/*
// @grant       none
// @version     1.0
// @author      -
// @description 12/30/2023, 2:32:16 AM
// ==/UserScript==
(() => {
  let title = document.querySelector("title");
  let newTitle = title.innerHTML.slice("FFmpeg: ".length);
  const getTitleFromHash = () => {
    try {
      return document.querySelector(`a[href="${window.location.hash}"]`).parentNode.parentNode.innerText.slice(2);
    } catch(err) {
      console.log(`error capturing title from hash: `, err)
    }
    return newTitle;
  }
  const updateTitleFromHash = () => {
    title.innerHTML = getTitleFromHash();
  }
  if(window.location.hash.length !== 0) {
    newTitle = getTitleFromHash();
  }
  window.addEventListener("hashchange", updateTitleFromHash);
  const headings = document.querySelectorAll('h2 span a[href^="#"]');

  document.addEventListener('scroll', (e) => {
    headings.forEach(ha => {
      const rect = ha.getBoundingClientRect();
      if(rect.top > 0 && rect.top < 150) {
        const location = window.location.toString().split('#')[0];
        history.replaceState(null, null, ha.href);
        updateTitleFromHash();
      }
    });
  });

  title.innerHTML = newTitle;
})();