From 14ddb2fb5c8d3ae1969bb569e364a50da41a2749 Mon Sep 17 00:00:00 2001
From: Skywt2003 <skywt2003@gmail.com>
Date: Fri, 12 Nov 2021 16:56:55 +0800
Subject: [PATCH] =?UTF-8?q?=E6=96=87=E7=AB=A0=E7=9B=AE=E5=BD=95=20TOC=20?=
 =?UTF-8?q?=E5=8A=9F=E8=83=BD?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 assets/style.css |  4 ++++
 functions.php    | 26 ++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/assets/style.css b/assets/style.css
index d7463e7..196e6b5 100644
--- a/assets/style.css
+++ b/assets/style.css
@@ -71,4 +71,8 @@ code {
 
 .friend {
     height: 80px;
+}
+
+html{
+    scroll-behavior: smooth;
 }
\ No newline at end of file
diff --git a/functions.php b/functions.php
index 5e58aa8..8729b67 100644
--- a/functions.php
+++ b/functions.php
@@ -136,6 +136,32 @@ function exContent($content){
     // <a class="btn btn-secondary" role="button" href="$1" target="_blank">$2</a>';
     // $content = preg_replace($pattern, $replacement, $content);
 
+    // 文章 TOC 功能
+    // [0]: 完整的匹配 <h2>conTent</h2>
+    // [1]: 匹配中的数字 2
+    // [2]: 匹配中的内容 conTent
+    if (preg_match_all('/<h(\d)>(.*)<\/h\d>/isU', $content, $outarr)){
+        $toc_out = "";
+        $minlevel = 6;
+        for ($key=0; $key<count($outarr[2]); $key++) $minlevel = min($minlevel, $outarr[1][$key]);
+
+        $curlevel = $minlevel-1;
+        for ($key=0; $key<count($outarr[2]); $key++) {
+            $ta = $content;
+            $tb = strpos($ta, $outarr[0][$key]);
+            $level = $outarr[1][$key];
+            // $content = substr($ta, 0, $tb). "<h{$level} id=\"toc_title{$key}\">{$outarr[2][$key]}</h{$level}>". substr($ta, strlen($outarr[0][$key])+$tb);
+            $content = substr($ta, 0, $tb). "<a id=\"toc_title{$key}\" style=\"position:relative; top:-50px\"></a>". substr($ta, $tb);
+            // 用伪锚点实现链接偏移。Safari 居然不支持！！
+            if ($level > $curlevel) $toc_out.=str_repeat("<ol>\n", $level-$curlevel);
+            elseif ($level < $curlevel) $toc_out.=str_repeat("</ol>\n", $curlevel-$level);
+            $curlevel = $level;
+            $toc_out .= "<li><a href=\"#toc_title{$key}\">{$outarr[2][$key]}</a></li>\n";
+        }
+        
+        $content = "<div id=\"tableOfContents\">{$toc_out}</div>". $content;
+    }
+
     return $content;
 }