docs: function () {
          const editor = this.editor
  
          // 禁用 document 拖拽事件
          const $document = $(document)
          $document.on('dragleave drop dragenter dragover', function (e) {
              e.preventDefault()
          })
  
          // 添加编辑区域拖拽事件
          const $textElem = editor.$textElem
          $textElem.on('drop', function (e) {
              e.preventDefault()
              const files = e.dataTransfer && e.dataTransfer.files
              if (!files || !files.length) {
                  return
              }
  
              // 上传图片
              const uploadImg = editor.uploadImg
              uploadImg.uploadImg(files)
          })
      }