slowdown overdo animation on Amazon (Prime) Music CloudPlayer for UserScript

amcp-calmdown.user.js

// ==UserScript==
// @name        AMCP calm down
// @namespace   http://noromanba.flavors.me
// @description slowdown overdo animation on Amazon (Prime) Music CloudPlayer for UserScript
// @include     https://www.amazon.tld/gp/dmusic/cloudplayer/*
// @include     https://music.amazon.tld/*
// @grant       none
// @noframes
// @run-at      document-start
// @version     2016.04.17.3
// @homepage    https://gist.github.com/noromanba/2fc4c8dc496dbe8d2050e42484bd9b40
// @downloadURL https://gist.github.com/noromanba/2fc4c8dc496dbe8d2050e42484bd9b40/raw/amcp-calmdown.user.js
// @license     MIT License http://nrm.mit-license.org/2016
// @author      noromanba   http://noromanba.flavors.me
// @icon        https://upload.wikimedia.org/wikipedia/commons/thumb/a/ab/United_States_sign_-_Slow.svg/32px-United_States_sign_-_Slow.svg.png
// @icon64      https://upload.wikimedia.org/wikipedia/commons/thumb/a/ab/United_States_sign_-_Slow.svg/64px-United_States_sign_-_Slow.svg.png
// ==/UserScript==

// Icon (PD by Fry1989)
// https://commons.wikimedia.org/wiki/File%3AUnited_States_sign_-_Slow.svg

// Devel
// https://gist.github.com/noromanba/2fc4c8dc496dbe8d2050e42484bd9b40


// related: window.amznMusic
(() => {
    'use strict';

    const addStyle = (() => {
        const parent = document.head || document.body || document.documentElement;

        const style = document.createElement('style');
        style.type = 'text/css';
        parent.appendChild(style);

        return (css) => {
            style.appendChild(document.createTextNode(css + '\n'));
        };
    })();

    // TODO
    //  - pause or slowdown transition
    //  - svg
    //*/
    addStyle(`
        .mainContentLoadingSpinnerHighlight {
            animation-duration: 0s !important;
            animation-play-state: paused !important;
        }
    `);
    /*/
    addStyle(`
         body *:not(.mainContentLoadingSpinnerHighlight) {
            animation-duration: 1s !important;
            transition-duration: 1s !important;
        }
    `);
    /*//*
    Array.from(document.body.querySelectorAll([
          'body',
         '*:not(.mainContentLoadingSpinnerHighlight)'
      ].join(' ')), node => {
          const style = getComputedStyle(node);
          if (style.animationDuration &&
              Number(style.animationDuration.replace(/[^\d\.]/g, '')) < 1) {
              style.animationDuration = '1s';
          } else if (style.transitionDuration &&
              Number(style.transitionDuration.replace(/[^\d\.]/g, '')) < 1) {
              style.transitionDuration = '1s';
          }
      });
    //*/
})();


// DBG
/*/
// detector
Array.from(document.body.querySelectorAll('*'), node => {
  const style = getComputedStyle(node);
  if (style.animationDuration && style.animationDuration !== '0s') {
    console.log('*animation', style.animationDuration, node);
    return node;
  } else if (style.transitionDuration && style.transitionDuration !== '0s') {
    console.log('*transitionDuration', style.transitionDuration, node);
    return node;
  }
}).filter(n => !!n);
// calm down
//const FPS = (1/1) + 's';
Array.from(document.body.querySelectorAll('*'), node => {
  const style = getComputedStyle(node);
  if (style.animationDuration && style.animationDuration !== '0s') {
    style.animationDuration = '1s';
  } else if (style.transitionDuration && style.transitionDuration !== '0s') {
    style.transitionDuration = '1s';
  }
});
//*/