ScrollX #

<script setup lang="ts">
import { useDebounceFn } from '@vueuse/core'

interface Props {
  showArrow?: boolean
}

withDefaults(defineProps<Props>(), {
  showArrow: true,
})

const translateX = ref(0)
const content = ref<HTMLElement | null>(null)
const wrapper = ref<HTMLElement | null>(null)
const isOverflow = ref(false)

const resetTranslateX = useDebounceFn((wrapperWidth, contentWidth) => {
  if (!isOverflow.value) translateX.value = 0
  else if (-translateX.value > contentWidth - wrapperWidth) translateX.value = wrapperWidth - contentWidth
  else if (translateX.value > 0) translateX.value = 0
}, 200)

const refreshIsOverflow = useDebounceFn(() => {
  const wrapperWidth = wrapper.value?.offsetWidth || 0
  const contentWidth = content.value?.offsetWidth || 0
  isOverflow.value = contentWidth > wrapperWidth
  resetTranslateX(wrapperWidth, contentWidth)
}, 200)

function handleMouseWheel(e: { wheelDelta: number }) {
  const { wheelDelta } = e
  const wrapperWidth = wrapper.value?.offsetWidth || 0
  const contentWidth = content.value?.offsetWidth || 0
  /**
   * @wheelDelta 平行滚动的值 >0： 右移  <0: 左移
   * @translateX 内容translateX的值
   * @wrapperWidth 容器的宽度
   * @contentWidth 内容的宽度
   */
  if (wheelDelta < 0) {
    if (wrapperWidth > contentWidth && translateX.value < -10) return
    if (wrapperWidth <= contentWidth && contentWidth + translateX.value - wrapperWidth < -10) return
  }
  if (wheelDelta > 0 && translateX.value > 10) return

  translateX.value += wheelDelta
  resetTranslateX(wrapperWidth, contentWidth)
}

const observer = new MutationObserver(refreshIsOverflow)
onMounted(() => {
  refreshIsOverflow()

  window.addEventListener('resize', refreshIsOverflow)
  // 监听内容宽度刷新是否超出
  observer.observe(content.value!, { childList: true })
})
onBeforeUnmount(() => {
  window.removeEventListener('resize', refreshIsOverflow)
  observer.disconnect()
})
</script>

<template>
  <div ref="wrapper" class="wrapper" @mousewheel.prevent="handleMouseWheel">
    <template v-if="showArrow && isOverflow">
      <div class="left" @click="handleMouseWheel({ wheelDelta: 120 })">
        <i i-ic:baseline-keyboard-arrow-left />
      </div>
      <div class="right" @click="handleMouseWheel({ wheelDelta: -120 })">
        <i i-ic:baseline-keyboard-arrow-right />
      </div>
    </template>

    <div
      ref="content"
      class="content"
      :class="{ overflow: isOverflow && showArrow }"
      :style="{
        transform: `translateX(${translateX}px)`,
      }"
    >
      <slot />
    </div>
  </div>
</template>

<style lang="scss" scoped>
.wrapper {
  display: flex;

  z-index: 9;
  overflow: hidden;
  position: relative;
  .content {
    padding: 0 10px;
    display: flex;
    align-items: center;
    flex-wrap: nowrap;
    transition: transform 0.5s;
    &.overflow {
      padding-left: 30px;
      padding-right: 30px;
    }
  }
  .left,
  .right {
    background-color: #fff;
    position: absolute;
    top: 0;
    bottom: 0;
    margin: auto;

    width: 20px;
    height: 35px;
    display: flex;
    align-items: center;
    justify-content: center;

    font-size: 18px;
    border: 1px solid #e0e0e6;
    border-radius: 2px;

    z-index: 2;
    cursor: pointer;
  }
  .left {
    left: 0;
  }
  .right {
    right: 0;
  }
}
</style>

<script setup lang="ts">
import ScrollX from './ScrollX.vue'
const num = ref(10)
</script>

<template>
  <div>
    <n-space>
      <n-button @click="num++" round type="primary">添加</n-button>
      <n-button @click="num && num--" round type="error">减少</n-button>
    </n-space>
    <ScrollX h-60>
      <n-tag v-for="i in num" :key="i" type="primary" px-15 mx-5 cursor-pointer>tag{{ i }}</n-tag>
    </ScrollX>
  </div>
</template>