一、使用效果

<template>
  <QqThreeSwitch v-model="value" />
  <!-- <SqThreeSwitch v-model="value" :options="['test1', 'test2', 'test3']">
    <template #left-action>
      <div style="display: flex">
        <IconMoon />
      </div>
    </template>
    <template #middle-action>
      <div style="display: flex">
        <IconSunny />
      </div>
    </template>
    <template #right-action>
      <div style="display: flex">
        <IconSystem />
      </div>
    </template>
  </SqThreeSwitch> -->
</template>

<script setup>
import SqThreeSwitch from './components/SqThreeSwitch.vue'
import { ref } from 'vue'

const value = ref(0)
</script>

二、SqThreeSwitch.vue源码

<template>
  <div class="sq-three-switch">
    <button class="focus-btn" :style="focusBtnStyle" @click="handleBtnClick">
      按下空格切换主题, 当前选择：{{ selectedOption }}
    </button>
    <div v-show="isMouseEnter" class="tooltip" tabindex="-1" :style="tooltipStyle">
      <div class="tip-text">{{ tooltipText }}</div>
      <svg class="tip-arrow" width="16px" height="8px" :style="tipArrowStyle">
        <polygon points="0,-1 8,7 16,-1" />
      </svg>
    </div>
    <div ref="selectedOptionRef" class="selected-option">
      <span>{{ selectedOption }}</span>
    </div>
    <div
      ref="controlRef"
      class="control plane-border"
      @click="handleClick"
      @mouseenter="handleMouseEnter"
      @mouseleave="handleMouseLeave"
      @mousemove="debouncedHandleMouseMove"
    ></div>
    <div class="plane"></div>
    <div class="badge-dots">
      <div
        v-for="(dot, index) in [0, 1, 2]"
        :key="index"
        class="dot"
        :class="{ 'dot-animate': dotAnimateFlag }"
        @animationend="handleAnimationEnd"
      ></div>
    </div>
    <div class="handle" :style="handleStyle">
      <slot v-if="modelValue === 0" name="left-action"></slot>
      <slot v-if="modelValue === 1" name="middle-action"></slot>
      <slot v-if="modelValue === 2" name="right-action"></slot>
    </div>
  </div>
</template>

<script setup>
import { ref, watch, computed, nextTick, onMounted, onBeforeUnmount } from 'vue'
import { useDebounceFn } from '@vueuse/core'

const props = defineProps({
  modelValue: {
    type: Number,
    default: 0
  },
  options: {
    type: Array,
    default: () => ['选项A', '选项B', '选项C']
  }
})
const emit = defineEmits(['update:modelValue'])

const selectedOptionRef = ref(null)

const focusBtnStyle = ref({})
nextTick(() => {
  focusBtnStyle.value = {
    width: `${selectedOptionRef.value.getBoundingClientRect().width + 50}px`
  }
})
watch(
  () => props.modelValue,
  () => {
    nextTick(() => {
      focusBtnStyle.value = {
        width: `${selectedOptionRef.value.getBoundingClientRect().width + 50}px`
      }
    })
  }
)

const controlRef = ref(null)
const haveTooltipSpace = ref(false)
const tipArrowStyle = computed(() => {
  return {
    transform: haveTooltipSpace.value ? '' : 'translateY(-26px) rotate(180deg)'
  }
})
function checkTooltipSpace(deadline) {
  if (deadline.timeRemaining() > 0) {
  
    const rect = controlRef.value?.getBoundingClientRect()
    if (rect) {
      haveTooltipSpace.value = rect.top >= 20
    }
  }
}
const debouncedCheckTooltipSpace = useDebounceFn(
  () => requestIdleCallback(checkTooltipSpace, { timeout: 200 }),
  200
)
let intervalId
onMounted(() => {
  debouncedCheckTooltipSpace()
  window.addEventListener('scroll', debouncedCheckTooltipSpace)
  window.addEventListener('resize', debouncedCheckTooltipSpace)
  intervalId = setInterval(debouncedCheckTooltipSpace, 2000)
  console.log('作者主页: https://blog.csdn.net/qq_39124701')
})
onBeforeUnmount(() => {
  window.removeEventListener('scroll', debouncedCheckTooltipSpace)
  window.removeEventListener('resize', debouncedCheckTooltipSpace)
  if (intervalId !== null) {
    clearInterval(intervalId)
  }
})

const isMouseEnter = ref(false)
const tooltipText = ref(props.options[props.modelValue])
const tooltipStyle = ref({
  left: props.modelValue === 0 ? '0px' : props.modelValue === 1 ? '20px' : '40px',
  top: haveTooltipSpace.value ? '0px' : '54px'
})

const selectedOption = computed(() => {
  return props.options[props.modelValue]
})

const dotAnimateFlag = ref(false)

const handleStyle = ref({
  left:
    props.modelValue === 0
      ? '2px'
      : props.modelValue === 1
        ? 'calc(50% - 9px)'
        : 'calc(100% - 19px)'
})
watch(
  () => props.modelValue,
  (newValue) => {
    handleStyle.value = {
      left: newValue === 0 ? '2px' : newValue === 1 ? 'calc(50% - 9px)' : 'calc(100% - 19px)'
    }
  }
)

function handleClick(/** @type { MouseEvent } */ event) {
  /** @type { Element } */
  const eventTarget = event.target
  const rect = eventTarget.getBoundingClientRect()
  const clickX = event.clientX - rect.left
  const oneThirdWidth = rect.width / 3

  if (clickX < oneThirdWidth) {
    if (props.modelValue === 0) {
      dotAnimateFlag.value = true
    }
    emit('update:modelValue', 0)
  } else if (clickX > oneThirdWidth * 2) {
    if (props.modelValue === 2) {
      dotAnimateFlag.value = true
    }
    emit('update:modelValue', 2)
  } else {
    if (props.modelValue === 1) {
      dotAnimateFlag.value = true
    }
    emit('update:modelValue', 1)
  }
}
function handleBtnClick() {
  if (props.modelValue === 0) {
    emit('update:modelValue', 1)
  } else if (props.modelValue === 1) {
    emit('update:modelValue', 2)
  } else if (props.modelValue === 2) {
    emit('update:modelValue', 0)
  }
}
function handleMouseEnter() {
  isMouseEnter.value = true
}
function handleMouseLeave() {
  isMouseEnter.value = false
}
const debouncedHandleMouseMove = useDebounceFn(handleMouseMove, 40)
function handleMouseMove(event) {
  if (!isMouseEnter.value) {
    return
  }
  const rect = event.target.getBoundingClientRect()
  const clickX = event.clientX - rect.left
  const oneThirdWidth = rect.width / 3

  if (clickX < oneThirdWidth) {
    tooltipText.value = props.options[0]
    tooltipStyle.value = { left: '0px', top: haveTooltipSpace.value ? '0px' : '54px' }
  } else if (clickX > oneThirdWidth * 2) {
    tooltipText.value = props.options[2]
    tooltipStyle.value = { left: 'calc(100% - 21px)', top: haveTooltipSpace.value ? '0px' : '54px' }
  } else {
    tooltipText.value = props.options[1]
    tooltipStyle.value = { left: 'calc(50% - 11px)', top: haveTooltipSpace.value ? '0px' : '54px' }
  }
}

function handleAnimationEnd() {
  dotAnimateFlag.value = false
}
</script>

<style scoped>
.sq-three-switch {
  position: relative;
  width: 60px;
  height: 20px;
  /* scale: 5;
  transform-origin: 0% 0%;
  z-index: 1; */
}
.sq-three-switch > * {
  position: absolute;
}
.sq-three-switch > .plane,
.sq-three-switch > .badge-dots,
.sq-three-switch > .handle {
  pointer-events: none;
}
.sq-three-switch > .focus-btn {
  height: 100%;
  border-radius: 10px;
  border: 0;
  outline-offset: 1px;
  font-size: 0;
}
.sq-three-switch > .focus-btn:focus {
  outline: 2px solid #409eff;
}
.sq-three-switch > .tooltip {
  z-index: 1;
  transform: translateY(-27px);
  white-space: nowrap;
  background-color: #e6e6e6;
  border: 1px solid gray;
  border-radius: 4px;
  padding: 1px 11px;
  transition: left 0.2s;
}
.sq-three-switch > .tooltip > .tip-text {
  font-size: 12px;
  color: black;
}
.sq-three-switch > .tooltip > .tip-arrow {
  position: absolute;
  top: 18px;
  left: 1px;
}
.sq-three-switch > .tooltip > .tip-arrow polygon {
  fill: #e6e6e6;
  stroke: gray;
  stroke-width: 1;
}
.sq-three-switch > .selected-option {
  height: 100%;
  background: linear-gradient(to right, #a8d4ff, #409eff 16px);
  border-radius: 10px;
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
  transform: translateX(50px);
  display: flex;
  justify-content: center;
  font-size: 14px;
  color: white;
  white-space: nowrap;
}
.sq-three-switch > .selected-option > span {
  padding-left: 16px;
  padding-right: 10px;
  user-select: none;
}
.sq-three-switch > .control {
  width: 100%;
  height: 20px;
  border-radius: 10px;
  background: #409eff;
  cursor: pointer;
}
.sq-three-switch > .plane {
  top: 1px;
  left: 1px;
  width: calc(100% - 2px);
  height: 18px;
  border-radius: 10px;
  background: #409eff;
}
.sq-three-switch > .badge-dots > .dot {
  position: absolute;
  top: 8px;
  left: 8px;
  width: 4px;
  height: 4px;
  border-radius: 100%;
  transition: all 0.3s cubic-bezier(0.22, 0.61, 0.36, 1);
  background-color: white;
}
.sq-three-switch > .badge-dots > .dot:nth-child(2) {
  left: 27px;
}
.sq-three-switch > .badge-dots > .dot:nth-child(3) {
  left: 47px;
}
.dot-animate {
  animation: dotAnimation 0.3s;
}
@keyframes dotAnimation {
  0% {
    background-color: white;
  }
  25% {
    background-color: black;
  }
  50% {
    background-color: white;
  }
  75% {
    background-color: black;
  }
  100% {
    background-color: white;
  }
}
.sq-three-switch > .handle {
  top: 2px;
  left: 2px;
  width: 16px;
  height: 16px;
  border-radius: 100%;
  transition: all 0.3s cubic-bezier(0.22, 0.61, 0.36, 1);
  background-color: white;
}

html.dark .sq-three-switch > .tooltip {
  background-color: #303133;
}
html.dark .sq-three-switch > .tooltip > .tip-arrow polygon {
  fill: #303133;
}
html.dark .sq-three-switch > .tooltip > .tip-text {
  color: white;
}
</style>