Google Tabindexer

Google の検索結果で [TAB] キーによる快適なキーボード操作を可能にします。

このスクリプトの質問や評価の投稿はこちら通報はこちらへお寄せください。
// ==UserScript==
// @name        Google Tabindexer
// @name:ja     Google Tabindexer
// @name:zh-CN  Google Tabindexer
// @description Enable comfortable [TAB] key navigation by keyboard shortcut on Google search.
// @description:ja Google の検索結果で [TAB] キーによる快適なキーボード操作を可能にします。
// @description:zh-CN Google 的搜索结果允许使用 [TAB] 键进行舒适的键盘操作。
// @namespace   knoa.jp
// @include     https://www.google.*/search?*
// @version     1.2.4
// @grant       none
// ==/UserScript==

(function(){
  const SCRIPTNAME = 'GoogleTabindexer';
  const DEBUG = false;/*
[update] 1.2.4
fix for google's update.

[todo]
ターゲット要素に背景色?単純なリンク要素以外だと適用しにくいかな。
ブロック要素の指定も含めて定義するか。
shift戻るときのbottom判定にも使える。

Twitterのみ特殊な件、テキトー対応しただけ
https://www.google.co.jp/search?q=%22%E5%86%AC%E9%87%8E%E3%83%A6%E3%83%9F%22
*/
  if(window === top && console.time) console.time(SCRIPTNAME);
  const POSITION = (50/100);/* anchor target position scroll to */
  const SELECTORS = [
    'input[title]',/* search */
    '#hdtbSum a:not([tabindex="-1"])',/* top navigations */
    '.zTpPx g-link > a',/* special twitter heading */
    '#search div.g [data-hveid] > div > a',/**** main headings!! ****/
    /* sub pages vary too much */
    '[aria-label^="Page"]',/* paging */
    '#pnprev',/* paging */
    '#pnnext',/* paging */
    '#tads a:not([style])[id]',/* ads */
    'h3[role="heading"] a',/* images */
    '[data-init-vis="true"] g-inner-card a',/* videos */
    'lazy-load-item a',/* news */
  ];
  const FOCUSFIRST = '#search div.g [data-hveid] > div > a';
  const INDEX = '1';/* set 1 to prevent default tab focuses */
  const FLAGNAME = 'tabindexer';/* should be lowercase */
  let elements = {}, indexedElements = [];
  let core = {
    initialize: function(){
      core.addTabindex(document.body);
      core.focusFirst();
      core.observe();
      core.tabToScroll();
      core.addStyle();
    },
    addTabindex: function(node){
      for(let i = 0; SELECTORS[i]; i++){
        let es = node.querySelectorAll(SELECTORS[i]);
        if(es === null) log('Not found:', SELECTORS[i]);
        for(let j = 0; es[j]; j++){
          es[j].tabIndex = INDEX;
          es[j].dataset[FLAGNAME] = SELECTORS[i];
        }
      }
      indexedElements = document.querySelectorAll(`[data-${FLAGNAME}]`);
      for(let i = 0; indexedElements[i]; i++){
        indexedElements[i].previousTabindexElement = indexedElements[i - 1];
        indexedElements[i].nextTabindexElement = indexedElements[i + 1];
      }
    },
    focusFirst: function(){
      let target = document.querySelector(FOCUSFIRST);
      core.showTarget(target);
      target.focus();
    },
    observe: function(){
      let body = document.body;
      observe(body, function(records){
        core.addTabindex(body);
      }, {childList: true, subtree: true});
    },
    tabToScroll: function(){
      window.addEventListener('keydown'/*keypress doesn't fire on tab key*/, function(e){
        if(e.key !== 'Tab') return;/* catch only Tab key */
        if(e.altKey || e.ctrlKey || e.metaKey) return;
        let target = (e.shiftKey) ? e.target.previousTabindexElement : e.target.nextTabindexElement;
        if(target) core.showTarget(target, e.shiftKey);
      }, true);
    },
    showTarget: function(target, shiftKey){
      let scroll = function(x, y, deltaY){
        setTimeout(function(){window.scrollTo(x, y + deltaY*(100 - 9**2)/100)}, 0*(1000/60));
        setTimeout(function(){window.scrollTo(x, y + deltaY*(100 - 8**2)/100)}, 1*(1000/60));
        setTimeout(function(){window.scrollTo(x, y + deltaY*(100 - 7**2)/100)}, 2*(1000/60));
        setTimeout(function(){window.scrollTo(x, y + deltaY*(100 - 6**2)/100)}, 3*(1000/60));
        setTimeout(function(){window.scrollTo(x, y + deltaY*(100 - 5**2)/100)}, 4*(1000/60));
        setTimeout(function(){window.scrollTo(x, y + deltaY*(100 - 4**2)/100)}, 5*(1000/60));
        setTimeout(function(){window.scrollTo(x, y + deltaY*(100 - 3**2)/100)}, 6*(1000/60));
        setTimeout(function(){window.scrollTo(x, y + deltaY*(100 - 2**2)/100)}, 7*(1000/60));
        setTimeout(function(){window.scrollTo(x, y + deltaY*(100 - 1**2)/100)}, 8*(1000/60));
        setTimeout(function(){window.scrollTo(x, y + deltaY*(100 - 0**2)/100)}, 9*(1000/60));
      };
      let innerHeight = window.innerHeight, scrollX = window.scrollX, scrollY = window.scrollY;
      let rect = target.getBoundingClientRect()/* rect.top: from top of the window */;
      switch(true){
        case(shiftKey === true && rect.bottom < innerHeight*POSITION):/* target is above the POSITION */
          scroll(scrollX, scrollY, rect.bottom - innerHeight*POSITION);/* position the target to (POSITION) from top */
          break;
        case(shiftKey === false && innerHeight*(1 - POSITION) < rect.top):/* target is below the POSITION */
          scroll(scrollX, scrollY, rect.top - innerHeight*(1 - POSITION));/* position the target to (1 - POSITION) from top */
          break;
        default:
          /* stay scrollY */
          break;
      }
    },
    addStyle: function(name = 'style'){
      let style = createElement(core.html[name]());
      document.head.appendChild(style);
      if(elements[name] && elements[name].isConnected) document.head.removeChild(elements[name]);
      elements[name] = style;
    },
    html: {
      style: () => `
        <style type="text/css">
          div.g [data-hveid] > div > a:focus,
          g-link a:focus,
          g-inner-card a:focus{
            outline: 0;
          }
          div.g [data-hveid] > div > a:focus h3,
          g-inner-card a:focus [role="heading"]{
            text-decoration: underline;
          }
          div.g [data-hveid] > div,
          g-link,
          g-inner-card a [role="heading"]{
            position: relative;
            overflow: visible !important;
          }
          div.g [data-hveid] > div > a:focus:before,
          g-link a:focus:before,
          g-inner-card a:focus [role="heading"]:before{
            content: "▶";
            font-size: medium;
            color: lightgray;
            position: absolute;
            left: -1.25em;
            top: 0.1em;
          }
          /* pagenation */
          a:focus > h3 > div{
            background: #eee;
            border: 1px solid #ccc;
          }
        </style>
      `,
    },
  };
  const createElement = function(html){
    let outer = document.createElement('div');
    outer.innerHTML = html;
    return outer.firstElementChild;
  };
  const observe = function(element, callback, options = {childList: true, characterData: false, subtree: false, attributes: false, attributeFilter: undefined}){
    let observer = new MutationObserver(callback.bind(element));
    observer.observe(element, options);
    return observer;
  };
  const log = function(){
    if(!DEBUG) return;
    let l = log.last = log.now || new Date(), n = log.now = new Date();
    let error = new Error(), line = log.format.getLine(error), callers = log.format.getCallers(error);
    //console.log(error.stack);
    console.log(
      SCRIPTNAME + ':',
      /* 00:00:00.000  */ n.toLocaleTimeString() + '.' + n.getTime().toString().slice(-3),
      /* +0.000s       */ '+' + ((n-l)/1000).toFixed(3) + 's',
      /* :00           */ ':' + line,
      /* caller.caller */ (callers[2] ? callers[2] + '() => ' : '') +
      /* caller        */ (callers[1] || '') + '()',
      ...arguments
    );
  };
  log.formats = [{
      name: 'Firefox Scratchpad',
      detector: /MARKER@Scratchpad/,
      getLine: (e) => e.stack.split('\n')[1].match(/([0-9]+):[0-9]+$/)[1],
      getCallers: (e) => e.stack.match(/^[^@]*(?=@)/gm),
    }, {
      name: 'Firefox Console',
      detector: /MARKER@debugger/,
      getLine: (e) => e.stack.split('\n')[1].match(/([0-9]+):[0-9]+$/)[1],
      getCallers: (e) => e.stack.match(/^[^@]*(?=@)/gm),
    }, {
      name: 'Firefox Greasemonkey 3',
      detector: /\/gm_scripts\//,
      getLine: (e) => e.stack.split('\n')[1].match(/([0-9]+):[0-9]+$/)[1],
      getCallers: (e) => e.stack.match(/^[^@]*(?=@)/gm),
    }, {
      name: 'Firefox Greasemonkey 4+',
      detector: /MARKER@user-script:/,
      getLine: (e) => e.stack.split('\n')[1].match(/([0-9]+):[0-9]+$/)[1] - 500,
      getCallers: (e) => e.stack.match(/^[^@]*(?=@)/gm),
    }, {
      name: 'Firefox Tampermonkey',
      detector: /MARKER@moz-extension:/,
      getLine: (e) => e.stack.split('\n')[1].match(/([0-9]+):[0-9]+$/)[1] - 6,
      getCallers: (e) => e.stack.match(/^[^@]*(?=@)/gm),
    }, {
      name: 'Chrome Console',
      detector: /at MARKER \(<anonymous>/,
      getLine: (e) => e.stack.split('\n')[2].match(/([0-9]+):[0-9]+\)$/)[1],
      getCallers: (e) => e.stack.match(/[^ ]+(?= \(<anonymous>)/gm),
    }, {
      name: 'Chrome Tampermonkey',
      detector: /at MARKER \((userscript\.html|chrome-extension:)/,
      getLine: (e) => e.stack.split('\n')[2].match(/([0-9]+):1\)$/)[1] - 4,
      getCallers: (e) => e.stack.match(/[^ ]+(?= \((userscript\.html|chrome-extension:))/gm),
    }, {
      name: 'Edge Console',
      detector: /at MARKER \(eval/,
      getLine: (e) => e.stack.split('\n')[2].match(/([0-9]+):[0-9]+\)$/)[1],
      getCallers: (e) => e.stack.match(/[^ ]+(?= \(eval)/gm),
    }, {
      name: 'Edge Tampermonkey',
      detector: /at MARKER \(Function/,
      getLine: (e) => e.stack.split('\n')[2].match(/([0-9]+):[0-9]+\)$/)[1] - 4,
      getCallers: (e) => e.stack.match(/[^ ]+(?= \(Function)/gm),
    }, {
      name: 'Safari',
      detector: /^MARKER$/m,
      getLine: (e) => 0,/*e.lineが用意されているが最終呼び出し位置のみ*/
      getCallers: (e) => e.stack.split('\n'),
    }, {
      name: 'Default',
      detector: /./,
      getLine: (e) => 0,
      getCallers: (e) => [],
    }];
  log.format = log.formats.find(function MARKER(f){
    if(!f.detector.test(new Error().stack)) return false;
    //console.log('//// ' + f.name + '\n' + new Error().stack);
    return true;
  });
  core.initialize();
  if(window === top && console.timeEnd) console.timeEnd(SCRIPTNAME);
})();