Vue3下使用vue-grid-layout从外部拖入demo10

由于Vue3文档缺失，示例10也是也跑不起来，这边参考示例改动了一下。

改动的点主要是this指向、$children相关的问题
在Vue3中移除了$children可以使用$ref替代

参考文章：计算坐标方法重写、文档示例

关键点：计算中的子组件取值使用ref绑定即可

对于循环的Dom树可以参考模板引用

完整代码：

	<template>
	  <div class="user-canvas" @dragenter.prevent @dragover.prevent>
	    <div id="content" class="w-full pb-16">
	      <grid-layout
	        class="min-h-screen"
	        ref="gridlayout"
	        :layout.sync="gridConfig.layout"
	        :col-num="60"
	        :row-height="30"
	        :vertical-compact="false"
	        :use-css-transforms="true"
	      >
	        <grid-item
	          ref="gridItemRefs"
	          v-for="item in gridConfig.layout"
	          class="h-full select-none relative overflow-hidden"
	          :static="item.static"
	          :x="item.x"
	          :y="item.y"
	          :w="item.w"
	          :h="item.h"
	          :i="item.i"
	          :minW="8"
	          :minH="2"
	        >
	         	<div>{{item.key}}</div>
	        </grid-item>
	      </grid-layout>
	    </div>
	  </div>
	</template>

	import { ref, onUnmounted } from 'vue'
	
	// ref
	const gridlayout = ref(null)
	const gridItemRefs = ref([])
	
	// 计算坐标用
	let mouseXY = { x: null, y: null }
	let DragPos = { x: null, y: null, w: 4, h: 4, i: null }

	const gridConfig ={layout:[{x: 0,y: 3,w: 4,h: 12,i: '1',static: true,moved: false}
	]}
	
	const handleDrop = (event) => {
	  event.preventDefault()
	  // TODO
	}
	
	// 开始拖动
	const drag = (e) => {
	  let parentRect = document.getElementById('content').getBoundingClientRect()
	  let mouseInGrid = false
	  if (
	    mouseXY.x > parentRect.left &&
	    mouseXY.x < parentRect.right &&
	    mouseXY.y > parentRect.top &&
	    mouseXY.y < parentRect.bottom
	  ) {
	    mouseInGrid = true
	  }
	
	  if (mouseInGrid === true && gridConfig.layout.findIndex((item) => item.i === 'drop') === -1) {
	    gridConfig.layout.push({
	      x: (gridConfig.layout.length * 2) % 12,
	      y: gridConfig.layout.length + 12, // puts it at the bottom
	      w: gridConfig.dragType?.w || 4,
	      h: gridConfig.dragType?.h || 4,
	      i: 'drop'
	    })
	  }
	  let index = gridConfig.layout.findIndex((item) => item.i === 'drop')
	  if (index !== -1) {
	    try {
	      gridItemRefs.value[gridConfig.layout.length - 1].$refs.item.style.display = 'none'
	    } catch {}
	    let el = gridItemRefs.value[index]
	    // el.dragging = { top: mouseXY.y - parentRect.top, left: mouseXY.x - parentRect.left }
	    let new_pos = calcXY(el, mouseXY.y - parentRect.top, mouseXY.x - parentRect.left, 1, 1)
	
	    if (mouseInGrid === true) {
	      // 红色游标部分
	      gridlayout.value.dragEvent(
	        'dragstart',
	        'drop',
	        new_pos.x,
	        new_pos.y,
	        gridConfig.dragType?.h || 4,
	        gridConfig.dragType?.w || 4
	      )
	      DragPos.i = String(index)
	      DragPos.x = gridConfig.layout[index].x
	      DragPos.y = gridConfig.layout[index].y
	    }
	    if (mouseInGrid === false) {
	      gridlayout.value.dragEvent('dragend', 'drop', new_pos.x, new_pos.y, 1, 1)
	      gridConfig.layout = gridConfig.layout.filter((obj) => obj.i !== 'drop')
	    }
	  }
	}
	
	// 释放拖动
	const dragend = (e) => {
	  let parentRect = document.getElementById('content').getBoundingClientRect()
	  let mouseInGrid = false
	  if (
	    mouseXY.x > parentRect.left &&
	    mouseXY.x < parentRect.right &&
	    mouseXY.y > parentRect.top &&
	    mouseXY.y < parentRect.bottom
	  ) {
	    mouseInGrid = true
	  }
	  if (mouseInGrid === true) {
	    gridlayout.value.dragEvent('dragend', 'drop', DragPos.x, DragPos.y, 1, 1)
	    gridConfig.addGridItem(DragPos)
	    gridConfig.layout = gridConfig.layout.filter((obj) => obj.i !== 'drop')
	  }
	  gridItemRefs.value[gridConfig.layout.length - 1].$refs.item.style.display = 'none'
	
	}
	
	// 计算坐标
	const calcXY = (el, top, left, width, height) => {
	  const colWidth = el.calcColWidth()
	  let x = Math.round((left - 10) / (colWidth + 10))
	  let y = Math.round((top - 10) / (el.rowHeight + 10))
	  const _width = width || el.innerW
	  const _height = height || el.innerH
	  x = Math.max(Math.min(x, el.cols - _width), 0)
	  y = Math.max(Math.min(y, el.maxRows - _height), 0)
	  return { x, y }
	}
	
	
	// 加载完成后监听鼠标事件
	onMounted(() => {
	  document.addEventListener(
	    'dragover',
	    function (e) {
	      mouseXY.x = e.clientX
	      mouseXY.y = e.clientY
	    },
	    false
	  )
	})
	
	// 销毁时关闭监听
	onUnmounted(() => {
	  document.removeEventListener(
	    'dragover',
	    function (e) {
	      mouseXY.x = null
	      mouseXY.y = null
	    },
	    false
	  )
	})