refactor: 将 BackTop 组件移动到 App.vue

src/ui/components/FaBackToTop/index.vue

@@ -0,0 +1,69 @@
+<script setup lang="ts">
+import { useTimeoutFn } from '@vueuse/core'
+
+defineOptions({
+  name: 'BackTop',
+})
+
+const transitionClass = {
+  enterActiveClass: 'ease-out duration-300',
+  enterFromClass: 'opacity-0 translate-y-4 lg-translate-y-0 lg-scale-95',
+  enterToClass: 'opacity-100 translate-y-0 lg-scale-100',
+  leaveActiveClass: 'ease-in duration-200',
+  leaveFromClass: 'opacity-100 translate-y-0 lg-scale-100',
+  leaveToClass: 'opacity-0 translate-y-4 lg-translate-y-0 lg-scale-95',
+}
+
+onMounted(() => {
+  window.addEventListener('scroll', handleScroll)
+  handleScroll()
+})
+onBeforeUnmount(() => {
+  window.removeEventListener('scroll', handleScroll)
+})
+
+let timeout: (() => void) | undefined
+
+const show = ref(false)
+const scrollTop = ref(0)
+function handleScroll() {
+  scrollTop.value = document.documentElement.scrollTop
+}
+watch(scrollTop, (val) => {
+  if (val >= 200) {
+    handleMouseenter()
+    handleMouseleave()
+  }
+})
+
+function handleMouseenter() {
+  timeout?.()
+  // 此处setTimeout是为了避免移动端下和click事件同时触发
+  setTimeout(() => {
+    show.value = true
+  }, 0)
+}
+
+function handleMouseleave() {
+  ;({ stop: timeout } = useTimeoutFn(() => {
+    show.value = false
+  }, 2000))
+}
+
+function handleBackToTop() {
+  show.value && document.documentElement.scrollTo({
+    top: 0,
+    behavior: 'smooth',
+  })
+}
+</script>
+
+<template>
+  <Teleport to="body">
+    <Transition v-bind="transitionClass">
+      <FaButton v-if="scrollTop >= 200" variant="outline" size="icon" class="fixed inset-b-4 z-1000 h-12 w-12 rounded-full transition-all -inset-e-9" :class="{ 'inset-e-3!': show }" @mouseenter="handleMouseenter" @mouseleave="handleMouseleave" @click="handleBackToTop">
+        <FaIcon name="i-icon-park-outline:to-top-one" class="size-6" />
+      </FaButton>
+    </Transition>
+  </Teleport>
+</template>