Vue中为el-dialog添加拖拽拉伸指令

Vue.directive("el-dialog-drag", {
  bind: (el, binding) => {
    //弹框可拉伸最小宽高
    let minWidth = 400;
    let minHeight = 300;
    //初始非全屏
    let isFullScreen = false;
    //当前宽高
    let nowWidth = 0;
    let nowHight = 0;
    //当前顶部高度
    let nowMarginTop = 0;
    //获取弹框头部（这部分可双击全屏）
    const dialogHeaderEl = el.querySelector(".el-dialog__header");
    //弹窗
    const dragDom = el.querySelector(".el-dialog");
    //给弹窗加上overflow auto；不然缩小时框内的标签可能超出dialog；
    dragDom.style.overflow = "auto";
    //清除选择头部文字效果
    dialogHeaderEl.onselectstart = new Function(" return false");
    //头部加上可拖动cursor
    dialogHeaderEl.style.cursor = "move";
    // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
    const sty = dragDom.currentStyle || window.getComputedStyle(dragDom, null);
    let moveDown = e => {
      // 鼠标按下，计算当前元素距离可视区的距离
      const disX = e.clientX - dialogHeaderEl.offsetLeft;
      const disY = e.clientY - dialogHeaderEl.offsetTop;
      // 获取到的值带px 正则匹配替换
      let styL, styT;
      // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
      if (sty.left.includes(" % ")) {
        styL = +document.body.clientWidth * (+sty.left.replace(/%/g, "") / 100);
        styT = +document.body.clientHeight * (+sty.top.replace(/%/g, "") / 100);
      } else {
        styL = +sty.left.replace(/\px/g, "");
        styT = +sty.top.replace(/\px/g, "");
      }
      document.onmousemove = function(e) {
        // 通过事件委托，计算移动的距离
        const l = e.clientX - disX;
        const t = e.clientY - disY;
        // 移动当前元素
        dragDom.style.left = `${l + styL}px`;
        dragDom.style.top = `${t + styT}px`;
        //将此时的位置传出去
        //binding.value({x:e.pageX,y:e.pageY})
      };
      document.onmouseup = function(e) {
        document.onmousemove = null;
        document.onmouseup = null;
      };
    };
    dialogHeaderEl.onmousedown = moveDown;
    // //双击头部效果
    // dialogHeaderEl.ondblclick = (e) => {
    // if (isFullScreen == false) {
    // nowHight = dragDom.clientHeight;
    // nowWidth = dragDom.clientWidth;
    // nowMarginTop = dragDom.style.marginTop;
    // dragDom.style.left = 0;
    // dragDom.style.top = 0;
    // dragDom.style.height = '100VH';
    // dragDom.style.width = '100VW';
    // dragDom.style.marginTop = 0;
    // isFullScreen = true;
    // dialogHeaderEl.style.cursor = 'initial';
    // dialogHeaderEl.onmousedown = null;
    // } else {
    // dragDom.style.height = 'auto';
    // dragDom.style.width = nowWidth + 'px';
    // dragDom.style.marginTop = nowMarginTop;
    // isFullScreen = false;
    // dialogHeaderEl.style.cursor = 'move';
    // dialogHeaderEl.onmousedown = moveDown;
    // }
    // }
    //拉伸
    let resizeEl = document.createElement("div");
    dragDom.appendChild(resizeEl);
    //在弹窗右下角加上一个10-10px的控制块
    resizeEl.style.cursor = "se-resize";
    resizeEl.style.position = "absolute";
    resizeEl.style.height = "10px";
    resizeEl.style.width = "10px";
    resizeEl.style.right = "0px";
    resizeEl.style.bottom = "0px";
    //鼠标拉伸弹窗
    resizeEl.onmousedown = e => {
      // 记录初始x位置
      const clientX = e.clientX;
      // 鼠标按下，计算当前元素距离可视区的距离
      const disX = e.clientX - resizeEl.offsetLeft;
      const disY = e.clientY - resizeEl.offsetTop;
      document.onmousemove = function(e) {
        e.preventDefault(); // 移动时禁用默认事件
        // 通过事件委托，计算移动的距离
        const x = e.clientX - disX + (e.clientX - clientX); //这里 由于elementUI的dialog控制居中的，所以水平拉伸效果是双倍
        const y = e.clientY - disY;
        //比较是否小于最小宽高
        dragDom.style.width = x > minWidth ? `${x}px` : minWidth + "px";
        dragDom.style.height = y > minHeight ? `${y}px` : minHeight + "px";
      };
      //拉伸结束
      document.onmouseup = function(e) {
        document.onmousemove = null;
        document.onmouseup = null;
      };
    };
  }
});