From 76c3f0b64c86539e33b27e4e868095dfe6942a6f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=BC=A0=E4=BC=A0=E9=BE=99?= <zclzone@outlook.com>
Date: Sat, 9 Jul 2022 14:38:38 +0800
Subject: [PATCH] perf: optimize ScrooX component.

---
 src/components/common/ScrollX.vue    | 56 +++++++++++++---------------
 src/layout/components/tags/index.vue | 11 +-----
 2 files changed, 26 insertions(+), 41 deletions(-)

diff --git a/src/components/common/ScrollX.vue b/src/components/common/ScrollX.vue
index 8f905ab..c0c823e 100644
--- a/src/components/common/ScrollX.vue
+++ b/src/components/common/ScrollX.vue
@@ -1,20 +1,19 @@
 <template>
-  <div ref="wrapper" class="tags-wrapper" @mousewheel.prevent="handleMouseWheel">
+  <div ref="wrapper" class="wrapper" @mousewheel.prevent="handleMouseWheel">
     <template v-if="showArrow && isOverflow">
-      <div class="left" @click="handleMouseWheel({ wheelDelta: 50 })">
+      <div class="left" @click="handleMouseWheel({ wheelDelta: 120 })">
         <icon-ic:baseline-keyboard-arrow-left />
       </div>
-      <div class="right" @click="handleMouseWheel({ wheelDelta: -50 })">
+      <div class="right" @click="handleMouseWheel({ wheelDelta: -120 })">
         <icon-ic:baseline-keyboard-arrow-right />
       </div>
     </template>
 
     <div
       ref="content"
-      class="tags-content"
+      class="content"
       :class="{ overflow: isOverflow && showArrow }"
       :style="{
-        height: height + 'px',
         transform: `translateX(${translateX}px)`,
       }">
       <slot />
@@ -24,37 +23,23 @@
 
 <script setup>
 import { debounce } from '@/utils'
-import { isNullOrUndef } from '@/utils/is'
 
 defineProps({
-  height: {
-    type: Number,
-    default: 50,
-  },
   showArrow: {
     type: Boolean,
     default: true,
   },
 })
 
-onMounted(() => {
-  refreshIsOverflow()
-})
-
 const translateX = ref(0)
 const content = ref(null)
 const wrapper = ref(null)
 const isOverflow = ref(false)
 
-function refreshIsOverflow(isIncrease) {
+const refreshIsOverflow = debounce(() => {
   isOverflow.value = content.value.offsetWidth > wrapper.value.offsetWidth
-  if (isNullOrUndef(isIncrease)) return
-  if (isOverflow.value) {
-    handleMouseWheel({ wheelDelta: isIncrease ? -100 : 100 })
-  } else if (!isIncrease && translateX.value < 0) {
-    handleMouseWheel({ wheelDelta: 100 })
-  }
-}
+}, 200)
+
 function handleMouseWheel(e) {
   const { wheelDelta } = e
   const wrapperWidth = wrapper.value.offsetWidth
@@ -65,15 +50,15 @@ function handleMouseWheel(e) {
    * @wrapperWidth 容器的宽度
    * @contentWidth 内容的宽度
    */
-  if (wheelDelta < 0 && -translateX.value > contentWidth - wrapperWidth + 10) {
-    return
+  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)
 }
 
@@ -87,20 +72,29 @@ const resetTranslateX = debounce(function (wrapperWidth, contentWidth) {
   }
 }, 200)
 
-defineExpose({
-  refreshIsOverflow,
+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>
 
 <style lang="scss" scoped>
-.tags-wrapper {
+.wrapper {
   display: flex;
   background-color: #fff;
-  position: sticky;
-  top: 0;
+
   z-index: 9;
   overflow: hidden;
-  .tags-content {
+  position: relative;
+  .content {
     padding: 0 10px;
     display: flex;
     align-items: center;
diff --git a/src/layout/components/tags/index.vue b/src/layout/components/tags/index.vue
index d8c0572..2b6c350 100644
--- a/src/layout/components/tags/index.vue
+++ b/src/layout/components/tags/index.vue
@@ -1,5 +1,5 @@
 <template>
-  <ScrollX ref="scrollX" :height="useTheme.tags.height">
+  <ScrollX :class="`h-${useTheme.tags.height}`">
     <n-tag
       v-for="tag in tagsStore.tags"
       :key="tag.path"
@@ -47,15 +47,6 @@ watch(
   { immediate: true }
 )
 
-const scrollX = ref(null)
-watch(
-  () => tagsStore.tags,
-  async (newVal, oldVal) => {
-    await nextTick()
-    scrollX.value?.refreshIsOverflow(newVal.length > oldVal.length)
-  }
-)
-
 const handleTagClick = (path) => {
   tagsStore.setActiveTag(path)
   router.push(path)