【vue】 vue2 自定义指令 实现全屏 、对话框拖拽

npm i screenfull@5.1.0 -S

import Vue from "vue";
// 全屏
import screenfull from "screenfull";
Vue.directive("screenfull", {
  bind(el, binding) {
    if (binding.modifiers.icon) {
      if (el.hasIcon) return;
      // 创建全屏图标
      const iconElement = document.createElement("i");
      iconElement.setAttribute("class", "el-icon-full-screen");
      iconElement.setAttribute("style", "margin-left:5px");
      el.appendChild(iconElement);
      el.hasIcon = true;
    }
    el.style.cursor = el.style.cursor || "pointer";
    // 监听点击全屏事件
    el.addEventListener("click", () => {
      if (!screenfull.isEnabled) {
        alert("浏览器不支持全屏");
        return;
      }
      screenfull.toggle();
    });
  },
});
// Dialog对话框拖拽
Vue.directive("drag", {
  bind(el, binding, vnode) {
    const dialogHeaderEl = el.querySelector(".el-dialog__header");
    const dragDom = el.querySelector(".el-dialog");
    dialogHeaderEl.style.cssText += ";cursor:move;";
    dragDom.style.cssText += ";top:0px;";
    // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
    const getStyle = (function () {
      if (window.document.currentStyle) {
        return (dom, attr) => dom.currentStyle[attr];
      } else {
        return (dom, attr) => getComputedStyle(dom, false)[attr];
      }
    })();
    dialogHeaderEl.onmousedown = (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;
      const dragDomWidth = dragDom.offsetWidth;
      const dragDomHeight = dragDom.offsetHeight;
      const screenWidth = document.body.clientWidth;
      const screenHeight = document.body.clientHeight;
      const minDragDomLeft = dragDom.offsetLeft;
      const maxDragDomLeft = screenWidth - dragDom.offsetLeft - dragDomWidth;
      const minDragDomTop = dragDom.offsetTop;
      const maxDragDomTop = screenHeight - dragDom.offsetTop - dragDomHeight;
      // 获取到的值带px 正则匹配替换
      let styL = getStyle(dragDom, "left");
      let styT = getStyle(dragDom, "top");
      if (styL.includes("%")) {
        styL = +document.body.clientWidth * (+styL.replace(/%/g, "") / 100);
        styT = +document.body.clientHeight * (+styT.replace(/%/g, "") / 100);
      } else {
        styL = +styL.replace(/\px/g, "");
        styT = +styT.replace(/\px/g, "");
      }
      document.onmousemove = function (e) {
        // 通过事件委托，计算移动的距离
        let left = e.clientX - disX;
        let top = e.clientY - disY;
        // 边界处理
        if (-left > minDragDomLeft) {
          left = -minDragDomLeft;
        } else if (left > maxDragDomLeft) {
          left = maxDragDomLeft;
        }
        if (-top > minDragDomTop) {
          top = -minDragDomTop;
        } else if (top > maxDragDomTop) {
          top = maxDragDomTop;
        }
        // 移动当前元素
        dragDom.style.cssText += `;left:${left + styL}px;top:${top + styT}px;`;
        // emit onDrag event
        vnode.child.$emit("dragDialog");
      };
      document.onmouseup = function () {
        document.onmousemove = null;
        document.onmouseup = null;
      };
    };
  },
});

<i class="el-icon-full-screen" v-screenfull></i>

<el-dialog
   v-drag
   title="标题"
   :visible.sync="dialogVisible"
   width="30%"
   :before-close="handleClose"
 >
 <el-dialog>