js滚动浏览器滚动条，js滚动元素滚动条

该代码可以实现滚动浏览器、任意dom元素水平方向、垂直方向的滚动条至指定位置。
常见场景有：置顶、置底
滚动效果：
水平方向滚动

垂直方向滚动

代码:

/**
   * 设置浏览器或元素滚动条滚动距离
   * @param ele dom元素或window对象
   * @param direction 滚动条方向，默认为y，可选值有：x、y
   * @param to 滚动条即将滚动到到位置
   * @param duration 时长（可选）
   * @param onDone 完成后的回调（可选）
   * @param onScroll 正在滚动中的回调（可选）
   * @returns {boolean}
   */
function scrollTo (ele, direction, to, duration, onDone, onScroll) {
    if (!ele) {
      return false;
    }
    if (!window.requestAnimationFrame) {
      window.requestAnimationFrame = (
        window.webkitRequestAnimationFrame ||
        window.mozRequestAnimationFrame ||
        window.msRequestAnimationFrame ||
        function (callback) {
          return window.setTimeout(callback, 1000/60);
        }
      );
    }
    if (!direction) {
      direction = 'y';
    }
    direction = direction == 'x' ? 'x' : 'y';
    var doDone = function () {
      if (typeof onDone == 'function') {
        onDone();
      }
    }
    var callOnScroll = function () {
      if (typeof onScroll == 'function') {
        onScroll();
      }
    }
    var attr = direction == 'x' ? 'scrollLeft' : 'scrollTop';
  var scrollLeft = function (ele) {
    if (ele && ele.nodeType == 1) {
      return ele.scrollLeft;
    }
    return window.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft || 0;
  }
  var scrollTop = function (ele) {
    if (ele && ele.nodeType == 1) {
      return ele.scrollTop;
    }
    return window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop || 0;
  }
    if (!duration || duration <= 0) {
      if (ele === window) {
        window.scrollTo(direction === 'x' ? to : scrollLeft(), direction === 'y' ? to : scrollTop());
      } else {
        ele[attr] = to;
      }
      callOnScroll();
      doDone();
      return true;
    }

    var diff = to - ele[attr];
    if (ele === window) {
      diff = to - (direction == 'x' ? scrollLeft() : scrollTop());
    }
    var perTick = (diff / duration) * 10;
    window.requestAnimationFrame(function () { // 实现缓动效果
      if (ele === window) {
        let x = scrollLeft();
        let y = scrollTop();
        window.scrollTo(direction === 'x' ? (x + perTick) : x, direction === 'y' ? (y + perTick) : y);
        callOnScroll();
        if (direction == 'x' ? scrollLeft() : scrollTop() !== to) {
          scrollTo(ele, direction, to, duration - 10, onDone, onScroll);
        } else {
          callOnScroll();
          doDone();
        }
        return;
      }
      ele[attr] += perTick;
      if (ele[attr] !== to) {
        callOnScroll();
        tool.scrollTo(ele, direction, to, duration - 10, onDone, onScroll);
      } else {
        callOnScroll();
        doDone();
      }
    });
    return true;
  }

调用：

var ele = document.getElementById('xxx');
// 滚动至元素最右侧
scrollTo(ele, 'x', ele.scrollWidth, 200);
// 滚动至元素顶部
scrollTo(ele, 'y', 0, 200);

// 滚动至浏览器顶部
scrollTo(window, 'y', 0, 200);