查询 twitter 登录页面中，用户名、密码框、登录按钮在页面中位置的脚本

tweet-login.js

window["setPosition"] = (...args) => { console.log(args); };
window["jsperform"] = (...args) => { console.log(args); };

// 探测登录页面中，用户名文本框、密码文本框和登录按钮的位置
;(function() {
  // 退出前做的工作
  var exit = () => {
    // 通知机器人 js 执行完毕
    window.jsperform("login");
  }, setPosition = (x, y) => {
    window.jsperform("setPosition", x, y);
  };

  var username = document.querySelector('[name="session[username_or_email]"]');
  var password = document.querySelector('[name="session[password]"]');
  if (!username || !password) {
    console.error("Cannot find the input element 'username' or 'password'.");
    exit();
    return ;
  }
  var button = document.querySelector('[data-testid="LoginForm_Login_Button"]');
  if (!button) {
    console.error("Cannot find the login button.");
    exit();
    return ;
  }
  
  // 获取元素的绝对位置坐标（像对于页面左上角）
  function getElementPagePosition(element) {
    //计算 x， y 坐标
    var actualLeft = element.offsetLeft;
    var actualTop = element.offsetTop;
    var current = element.offsetParent;
    while (current !== null) {
      actualLeft += current.offsetLeft;
      actualTop += (current.offsetTop + current.clientTop);
      current = current.offsetParent;
    }
    //返回结果
    return {x: actualLeft, y: actualTop};
  };

  // 获取元素的绝对位置坐标（像对于浏览器视区左上角）
  function getElementViewPosition(element) {
    var actualLeft = element.offsetLeft;
    var actualTop = element.offsetTop;
    var current = element.offsetParent;
    while (current !== null) {
      actualLeft += (current.offsetLeft + current.clientLeft);
      actualTop += (current.offsetTop + current.clientTop);
      current = current.offsetParent;
    }
    if (document.compatMode == "BackCompat"){
      var elementScrollLeft = document.body.scrollLeft;
      var elementScrollTop = document.body.scrollTop;
    } else {
      var elementScrollLeft = document.documentElement.scrollLeft;
      var elementScrollTop = document.documentElement.scrollTop;
    }
    var left = actualLeft - elementScrollLeft;
    var right = actualTop - elementScrollTop;
    return {x: left, y: right};
  };

  // 获取元素外边界的大小
  function getElementSize(element) {
    return {"width": element.offsetWidth, "height": element.offsetHeight};
  }

  // 获取元素大小
  function getElementContentSize(element) {
    var direction = ['width', 'height'],
        ret = {"width": element.offsetWidth, "height": element.offsetHeight},
        which, value, style, getStyle = function(el) {
          if ('getComputedStyle' in window) {
            return window.getComputedStyle(el, null);
          } else if ('currentStyle' in el) {
            return el.currentStyle;
          } else {
            return el.style;
          }
        };
    for (var i in direction) {
      which = direction[i] === 'width' ? ['Left', 'Right'] : ['Top', 'Bottom'];
      value = ret[direction[i]];
      style = getStyle(element);
      for (var j in which) {
        var a = which[j];
        value -= parseFloat(style[`border${a}Width`]);
        value -= parseFloat(style[`padding${a}`]);
      }
    }
    return ret;
  };

  var username_position = getElementViewPosition(username),
      username_size = getElementSize(username),
      password_position = getElementViewPosition(password),
      password_size = getElementSize(password),
      button_position = getElementViewPosition(button),
      button_size = getElementSize(button);
  
  // 设置
  if ('setPosition' in window) {
    var usr_x, usr_y, pwd_x, pwd_y, btn_x, btn_y,
        randomPosition = (m, n) => {
          return parseInt(m + n - Math.random() * (n / 2));
        };
    usr_x = randomPosition(username_position["x"], username_size["width"]);
    usr_y = randomPosition(username_position["y"], username_size["height"]);
    pwd_x = randomPosition(password_position["x"], password_size["width"]);
    pwd_y = randomPosition(password_position["y"], password_size["height"]);
    btn_x = randomPosition(button_position["x"], button_size["width"]);
    btn_y = randomPosition(button_position["y"], button_size["height"]);

    // 通知机器人
    setPosition('username', usr_x, usr_y);
    setPosition('password', pwd_x, pwd_y);
    setPosition('button', btn_x, btn_y);
  }

  exit();
  return ;
})();