Merge pull request #2538 from tangly1024/feat/theme-example-catalog

example主题添加目录

themes/example/components/Catalog.js

@@ -0,0 +1,94 @@
+import throttle from 'lodash.throttle'
+import { uuidToId } from 'notion-utils'
+import { useCallback, useEffect, useRef, useState } from 'react'
+
+/**
+ * 目录导航组件
+ * @param toc
+ * @returns {JSX.Element}
+ * @constructor
+ */
+const Catalog = ({ toc }) => {
+  // 监听滚动事件
+  useEffect(() => {
+    window.addEventListener('scroll', actionSectionScrollSpy)
+    actionSectionScrollSpy()
+    return () => {
+      window.removeEventListener('scroll', actionSectionScrollSpy)
+    }
+  }, [])
+
+  // 目录自动滚动
+  const tRef = useRef(null)
+  const tocIds = []
+
+  // 同步选中目录事件
+  const [activeSection, setActiveSection] = useState(null)
+  const throttleMs = 200
+  const actionSectionScrollSpy = useCallback(
+    throttle(() => {
+      const sections = document.getElementsByClassName('notion-h')
+      let prevBBox = null
+      let currentSectionId = activeSection
+      for (let i = 0; i < sections.length; ++i) {
+        const section = sections[i]
+        if (!section || !(section instanceof Element)) continue
+        if (!currentSectionId) {
+          currentSectionId = section.getAttribute('data-id')
+        }
+        const bbox = section.getBoundingClientRect()
+        const prevHeight = prevBBox ? bbox.top - prevBBox.bottom : 0
+        const offset = Math.max(150, prevHeight / 4)
+        // GetBoundingClientRect returns values relative to viewport
+        if (bbox.top - offset < 0) {
+          currentSectionId = section.getAttribute('data-id')
+          prevBBox = bbox
+          continue
+        }
+        // No need to continue loop, if last element has been detected
+        break
+      }
+      setActiveSection(currentSectionId)
+      const index = tocIds.indexOf(currentSectionId) || 0
+      tRef?.current?.scrollTo({ top: 28 * index, behavior: 'smooth' })
+    }, throttleMs)
+  )
+
+  // 无目录就直接返回空
+  if (!toc || toc.length < 1) {
+    return <></>
+  }
+
+  return (
+    <div className='px-3'>
+      <div
+        className='overflow-y-auto max-h-96 overscroll-none scroll-hidden'
+        ref={tRef}>
+        <nav className='h-full  text-black dark:text-gray-300'>
+          {toc.map(tocItem => {
+            const id = uuidToId(tocItem.id)
+            tocIds.push(id)
+            return (
+              <a
+                key={id}
+                href={`#${id}`}
+                className={`notion-table-of-contents-item duration-300 transform font-light
+              notion-table-of-contents-item-indent-level-${tocItem.indentLevel} `}>
+                <span
+                  style={{
+                    display: 'inline-block',
+                    marginLeft: tocItem.indentLevel * 16
+                  }}
+                  className={`truncate ${activeSection === id ? ' font-bold text-red-400 underline' : ''}`}>
+                  {tocItem.text}
+                </span>
+              </a>
+            )
+          })}
+        </nav>
+      </div>
+    </div>
+  )
+}
+
+export default Catalog

themes/example/components/SideBar.js

@@ -5,6 +5,7 @@ import dynamic from 'next/dynamic'
 import Link from 'next/link'
 import CONFIG from '../config'
 import Announcement from './Announcement'
+import Catalog from './Catalog'
 const ExampleRecentComments = dynamic(
   () => import('./RecentCommentListForExample')
 )
@@ -32,6 +33,16 @@ export const SideBar = props => {
 
   return (
     <>
+      {/* 目录 */}
+      {post?.toc && post?.toc.length > 2 && (
+        <aside className='w-full rounded shadow overflow-hidden mb-6 pb-4'>
+          <h3 className='text-sm bg-gray-100 text-gray-700 dark:bg-hexo-black-gray dark:text-gray-200 py-3 px-4 dark:border-hexo-black-gray border-b'>
+            {locale.COMMON.TABLE_OF_CONTENTS}
+          </h3>
+          <Catalog toc={post?.toc} />
+        </aside>
+      )}
+
       {/* 分类 */}
       <aside className='w-full rounded shadow overflow-hidden mb-6'>
         <h3 className='text-sm bg-gray-100 text-gray-700 dark:bg-hexo-black-gray dark:text-gray-200 py-3 px-4 dark:border-hexo-black-gray border-b'>