web-utils-super/onWindowResize.js

前端函数库

/**
 * window.onresize 事件 专用事件绑定器 v0.1 Alucelx
 * http://www.cnblogs.com/Alucelx/archive/2011/10/20/2219263.html
 * <description>
 *   用于解决 lte ie8 & chrome 及其他可能会出现的 原生 window.resize 事件多次执行的 BUG.
 * </description>
 * <methods>
 *   add: 添加事件句柄
 *   remove: 删除事件句柄
 * </methods>
 */
/* eslint-disable */

const onWindowResize = function () {
  // 事件队列
  var queue = [],
    indexOf =
      Array.prototype.indexOf ||
      function () {
        var i = 0,
          length = this.length;
        for (; i < length; i++) {
          if (this[i] === arguments[0]) {
            return i;
          }
        }

        return -1;
      };

  var isResizing = {}, // 标记可视区域尺寸状态， 用于消除 lte ie8 / chrome 中 window.onresize 事件多次执行的 bug
    lazy = true, // 懒执行标记
    listener = function (e) {
      // 事件监听器
      var h =
          window.innerHeight ||
          (document.documentElement && document.documentElement.clientHeight) ||
          document.body.clientHeight,
        w =
          window.innerWidth ||
          (document.documentElement && document.documentElement.clientWidth) ||
          document.body.clientWidth;

      if (h === isResizing.h && w === isResizing.w) {
        return null;
      } else {
        e = e || window.event;

        var i = 0,
          len = queue.length;
        for (; i < len; i++) {
          queue[i].call(this, e);
        }

        isResizing.h = h;
        isResizing.w = w;
      }
    };

  return {
    add: function (fn) {
      if (typeof fn === "function") {
        // 懒执行
        if (lazy) {
          if (window.addEventListener) {
            window.addEventListener("resize", listener, false);
          } else {
            window.attachEvent("onresize", listener);
          }

          lazy = false;
        }

        queue.push(fn);
      } else {
      }

      return this;
    },
    remove: function (fn) {
      if (typeof fn === "undefined") {
        queue = [];
      } else if (typeof fn === "function") {
        var i = indexOf.call(queue, fn);

        if (i > -1) {
          queue.splice(i, 1);
        }
      }

      return this;
    },
    clear: function () {
      if (queue.length >= 1) {
        // let newQueue = queue[0]
        queue.length = 1;
      }
    },
  };
}.call(this);

module.exports = onWindowResize;