<template>
  <div class="container" ref="container">
    <div class="drag" @mousedown="onTdMousedown($event)"></div>
  </div>
</template>

<script setup lang="ts">
import { reactive, ref } from 'vue';

// 目标元素
const props = defineProps<{
  target: HTMLElement;
}>();

const domInfo = reactive({
  baseW: 0,
  baseH: 0
});

const container = ref<HTMLElement>(null);

const updateTarget = (event: MouseEvent) => {
  if (!container.value) {
    console.error('drag--- 请传入一个HTMLElement节点');
    return;
  }
  // movementX/movementY
  // 两个鼠标移动事件间隔时间中当中鼠标移动的相对坐标;
  domInfo.baseW = container.value.clientWidth;
  domInfo.baseH = container.value.clientHeight;
  container.value!.style.width = `${domInfo.baseW + event.movementX}px`;
  container.value!.style.height = `${domInfo.baseH + event.movementY}px`;
};
// change 回调方式
const onTdMousedown = (e: MouseEvent) => {
  window.addEventListener('mousemove', updateTarget);
  window.onmouseup = function () {
    window.onmouseup = null;
    window.removeEventListener('mousemove', updateTarget);
  };
};
</script>

<style lang="scss" scoped>
.drag {
  position: absolute;
  width: 16px;
  height: 16px;
  bottom: 10px;
  // background: red;
  right: 10px;
  z-index: 999;
  border-radius: inherit;
  box-shadow: 2px 2px 0px -1px blue;
  cursor: move;
}

.container {
  width: 100px;
  height: 100px;
  background-color: #ccc;
  position: relative;
}
</style>