☰

TopScroll

Быстрая прокрутка страницы вверх/вниз.

  1. // ==UserScript==
  2. // @name	TopScroll
  3. // @description	Быстрая прокрутка страницы вверх/вниз.
  4. // @namespace	https://forum.mozilla-russia.org/viewtopic.php?pid=719386#p719386
  5. // @include 	*
  6. // @version	1.0
  7. // ==/UserScript==
  8.  
  9. topScroll = {
  10.  
  11.     injectDiv: function() {
  12.         var body = document.getElementsByTagName("body")[0];
  13.         var div = document.createElement("div");
  14.         div.id = "topscroll-chrome-extension-bar";
  15.         div.setAttribute("style", "position: fixed !important; top: 0 !important; left: 0 !important; bottom: 0 !important; margin: 0 !important; padding: 0 !important; width: 5px !important; height: 100% !important; border-style: none !important; box-shadow: none !important; opacity: 0 !important; z-index: 2147483647 !important;");
  16.         div.onclick = topScroll.scrollUp;
  17.         div.oncontextmenu = topScroll.scrollDown;
  18.         body.appendChild(div);
  19.     },
  20.  
  21.     scrollUp: function() {
  22.         if (window.pageYOffset === 0) {
  23.             topScroll.scrollTo(topScroll.lastScrollPosition);
  24.             topScroll.lastScrollPosition = 0;
  25.         } else {
  26.             topScroll.lastScrollPosition = window.pageYOffset;
  27.             topScroll.scrollTo(0);
  28.         }
  29.     },
  30.  
  31.     scrollDown: function() {
  32.         var bottomOffset = document.documentElement.scrollHeight - window.innerHeight;
  33.         if (window.pageYOffset === bottomOffset) {
  34.             topScroll.scrollTo(topScroll.lastScrollPosition);
  35.             topScroll.lastScrollPosition = bottomOffset;
  36.         } else {
  37.             topScroll.lastScrollPosition = window.pageYOffset;
  38.             topScroll.scrollTo(bottomOffset);
  39.         }
  40.         return false; // Prevent context menu appearing
  41.     },
  42.  
  43.     scrollTo: function(endY) {
  44.         var duration = 150;
  45.         var startY = window.scrollY;
  46.         var distance = Math.max(endY,0) - startY;
  47.         var startTime = new Date().getTime();
  48.         (function loopScroll() {
  49.             setTimeout(function () {
  50.                 var p = Math.min((new Date().getTime() - startTime) / duration, 1); // Progress 0→1
  51.                 var y = Math.max(Math.floor(startY + distance*(p < 0.5 ? 2*p*p : p*(4 - p*2)-1)), 0);
  52.                 window.scrollTo(window.pageXOffset, y);
  53.                 if (p < 1) {
  54.                     loopScroll();
  55.                 }
  56.             }, 1)
  57.         })();
  58.     }
  59. };
  60.  
  61. topScroll.injectDiv();