Vue3 realizes the image magnifying glass effect

<template>
  <div class="goods-image">
    <!-- Large image container -->
    <div
      class="large"
      :style="[
        {
          backgroundImage: `url(${imageList[curId]})`,
          backgroundPositionX: position.backgroundPositionX,
          backgroundPositionY: position.backgroundPositionY,
        },
      ]"
      v-if="isShow"
    ></div>
    <div class="middle" ref="target">
      <img :src="imageList[curId]" alt="" />
      <!-- Mask container -->
      <div class="layer" :style="{ left: left + 'px', top: top + 'px' }" v-if="isShow"></div>
    </div>
    <ul class="small">
      <li
        v-for="(img, i) in imageList"
        :key="i"
        @mouseenter="curId = i"
        :class="{ active: curId === i }"
      >
        <img :src="img" alt="" />
      </li>
    </ul>
  </div>
</template>
 
<script>
import { reactive, ref, watch } from 'vue'
import { useMouseInElement } from '@vueuse/core'
export default {
  name: 'GoodsImage',
  props: {
    imageList: {
      type: Array,
      default: () => {
        return []
      }
    }
  },
  setup () {
    const curId = ref(0)
    const target = ref(null)
    // elementX: the offset value of the mouse from the left side // elementY: the offset value of the table from the top // isOutside: whether it is outside the container (true for outside and false for inside)
    const { elementX, elementY, isOutside } = useMouseInElement(target)
    const left = ref(0) // The distance from the slider to the left const top = ref(0) // The distance from the slider to the top const isShow = ref(false) // Show and hide the large image and the mask image const position = reactive({ // The position of the large image display, the default is 0
      backgroundPositionX: 0,
      backgroundPositionY: 0
    })
    watch(
      //Monitoring object [elementX, elementY, isOutside],
      () => {
        if (elementX.value < 100) {
          // Minimum distance on the left left.value = 0
        }
        if (elementX.value > 300) {
          left.value = 200
        }
        if (elementX.value > 100 && elementX.value < 300) {
          left.value = elementX.value - 100
        }
        if (elementY.value < 100) {
          // Minimum distance on the left top.value = 0
        }
        if (elementY.value > 300) {
          top.value = 200
        }
        if (elementY.value > 100 && elementY.value < 300) {
          top.value = elementY.value - 100
        }
        // Control the movement of the background image // 1. The direction of the mask layer's movement is opposite to that of the background image // 2. Since the area ratio of the mask layer and the background image is 1:2, the background image moves two pixels for every pixel the mask layer moves // backgrondPosition: x, y;
        position.backgroundPositionX = -left.value * 2 + 'px'
        position.backgroundPositionY = -top.value * 2 + 'px'
 
        // When the value of isOutside changes, immediately negate it and assign it to isShow
        // isOutside: Is it outside the container? True for outside and false for inside
        isShow.value = !isOutside.value
      },
      {}
    )
    return {
      curId,
      target,
      left,
      top,
      position,
      isShow
    }
  }
}
</script>