判断点击位置不在遮罩层
    判断点击位置是否有拖动

    1. let mousedownTarget = false
    2. let mouseupTarget = false
    3. const onMaskClick = (e) => {
    4.   if (mousedownTarget && mouseupTarget) {
    5.     visible.value = false
    6.   }
    7.   mousedownTarget = mouseupTarget = false
    8. }
    9. const onMouseDown = (e) => {
    10.   mousedownTarget = e.target === e.currentTarget
    11. }
    12. const onMouseUp = (e) => {
    13.   mouseupTarget = e.target === e.currentTarget
    14. }