add manual/auto expand/collapse function to sub-sidebar.

src/core/event/scroll.js

@@ -36,7 +36,7 @@ function highlight(path) {
 
   const sidebar = dom.getNode('.sidebar');
   const anchors = dom.findAll('.anchor');
-  const wrap = dom.find(sidebar, '.sidebar-nav');
+  const wrap = dom.find(sidebar, '.app-sub-sidebar');
   let active = dom.find(sidebar, 'li.active');
   const doc = document.documentElement;
   const top = ((doc && doc.scrollTop) || document.body.scrollTop) - coverHeight;
@@ -70,12 +70,14 @@ function highlight(path) {
   li.classList.add('active');
   active = li;
 
+  updateTree(active);
+
   // Scroll into view
   // https://github.com/vuejs/vuejs.org/blob/master/themes/vue/source/js/common.js#L282-L297
   if (!hoverOver && dom.body.classList.contains('sticky')) {
     const height = sidebar.clientHeight;
     const curOffset = 0;
-    const cur = active.offsetTop + active.clientHeight + 40;
+    const cur = active.offsetTop + active.clientHeight + height / 2;
     const isInView =
       active.offsetTop >= wrap.scrollTop && cur <= wrap.scrollTop + height;
     const notThan = cur - curOffset < height;
@@ -85,6 +87,27 @@ function highlight(path) {
   }
 }
 
+function updateTree(active) {
+  let prevParents = dom.findAll('.parent');
+  let prevWifes = dom.findAll('.wife');
+  let prevChanges = dom.findAll('.change');
+  let prevExpands = dom.findAll('.expand');
+
+  prevParents.forEach(node => node.classList.remove('parent'));
+  prevWifes.forEach(node => node.classList.remove('wife'));
+  prevChanges.forEach(node => node.classList.remove('change'));
+  prevExpands.forEach(node => node.classList.remove('expand'));
+
+  let father = active.parentNode;
+  while (father && father.className !== 'app-sub-sidebar') {
+    father.classList.add('parent');
+    father = father.parentNode;
+  }
+
+  let wife = active.lastChild;
+  wife.nodeName === 'UL' && wife.classList.add('wife');
+}
+
 function getNavKey(path, id) {
   return `${decodeURIComponent(path)}?id=${decodeURIComponent(id)}`;
 }
@@ -143,14 +166,25 @@ export function scrollIntoView(path, id) {
     return;
   }
   const topMargin = config().topMargin;
+
+  let prevSections = dom.findAll('.current');
+  prevSections.forEach(node => node.classList.remove('current'));
+
   const section = dom.find('#' + id);
-  section && scrollTo(section, topMargin);
+  if (section) {
+    section.classList.add('current');
+    scrollTo(section, topMargin);
+  }
 
-  const li = nav[getNavKey(path, id)];
   const sidebar = dom.getNode('.sidebar');
   const active = dom.find(sidebar, 'li.active');
   active && active.classList.remove('active');
-  li && li.classList.add('active');
+
+  const li = nav[getNavKey(path, id)];
+  if (li) {
+    li.classList.add('active');
+    updateTree(li);
+  }
 }
 
 const scrollEl = dom.$.scrollingElement || dom.$.documentElement;

src/core/event/sidebar.js

@@ -42,6 +42,17 @@ export function collapse(el) {
       target.nextSibling.classList.contains('app-sub-sidebar')
     ) {
       dom.toggleClass(target.parentNode, 'collapse');
+    } else if (
+      target.nodeName === 'SPAN' &&
+      target.nextSibling &&
+      target.nextSibling.classList.contains('section-link')
+    ) {
+      dom.toggleClass(target, 'change');
+
+      let expand = target.nextSibling.nextSibling;
+      if (expand && expand.nodeName === 'UL') {
+        dom.toggleClass(expand, 'expand');
+      }
     }
   });
 }

src/core/render/compiler.js

@@ -277,7 +277,7 @@ export class Compiler {
       }
 
       const tree = this.cacheTree[currentPath] || genTree(toc, level);
-      html = treeTpl(tree, '<ul>{inner}</ul>');
+      html = treeTpl(tree, '<ul class="app-sub-sidebar">{inner}</ul>');
       this.cacheTree[currentPath] = tree;
     }
 
@@ -309,7 +309,7 @@ export class Compiler {
 
     cacheTree[currentPath] = tree;
     this.toc = [];
-    return treeTpl(tree);
+    return treeTpl(tree, '<ul class="app-sub-sidebar">{inner}</ul>');
   }
 
   header(text, level) {

src/core/render/tpl.js

@@ -84,19 +84,27 @@ export function cover() {
  * Render tree
  * @param  {Array} toc Array of TOC section links
  * @param  {String} tpl TPL list
+ * @param  {Boolean} using specified TPL for all level(true), or root only(false)
  * @return {String} Rendered tree
  */
-export function tree(toc, tpl = '<ul class="app-sub-sidebar">{inner}</ul>') {
+export function tree(toc, tpl = '<ul>{inner}</ul>', all = false) {
   if (!toc || !toc.length) {
     return '';
   }
 
   let innerHTML = '';
   toc.forEach(node => {
-    innerHTML += `<li><a class="section-link" href="${node.slug}">${node.title}</a></li>`;
     if (node.children) {
-      innerHTML += tree(node.children, tpl);
+      innerHTML += `<li class="has-children"><span></span><a class="section-link" href="${node.slug}">${node.title}</a>`;
+      if (!all) {
+        innerHTML += tree(node.children);
+      } else {
+        innerHTML += tree(node.children, tpl, true);
+      }
+    } else {
+      innerHTML += `<li><span></span><a class="section-link" href="${node.slug}">${node.title}</a>`;
     }
+    innerHTML += `</li>`;
   });
   return tpl.replace('{inner}', innerHTML);
 }

src/themes/basic/_layout.styl

@@ -470,3 +470,52 @@ body.close
 
   40%, 80%
     transform rotate(10deg)
+
+
+.app-sub-sidebar
+
+  ul
+    display none
+
+  ul.parent,
+  ul.wife,
+  ul.expand
+    display block
+
+  ul.parent.expand,
+  ul.wife.expand
+    display none
+
+  li span
+    display block
+    width 20px
+    font-family monospace
+    font-weight bold
+    font-size 20px
+    float left
+    &:after
+        content '\00A0'
+    &.change
+      &:after
+        content '\00A0'
+
+  li.has-children
+    > span
+      &:after
+        content '\203A'
+    > span.change
+      &:after
+        content '-'
+
+  li.parent,
+  li.has-children.active
+    > span
+      &:after
+        content '-'
+    > span.change
+      &:after
+        content '\203A'
+
+.current
+  span
+    color #c94922

src/themes/dolphin.styl

@@ -39,12 +39,7 @@ body
     color var(--theme-color, $color-primary)
     font-weight 600
 
-.app-sub-sidebar
-  li
-    &::before
-      content '-'
-      padding-right 4px
-      float left
+
 
 /* markdown content found on pages */
 .markdown-section h1, .markdown-section h2, .markdown-section h3, .markdown-section h4, .markdown-section strong

src/themes/vue.styl

@@ -39,13 +39,6 @@ body
     color var(--theme-color, $color-primary)
     font-weight 600
 
-.app-sub-sidebar
-  li
-    &::before
-      content '-'
-      padding-right 4px
-      float left
-
 /* markdown content found on pages */
 .markdown-section h1, .markdown-section h2, .markdown-section h3, .markdown-section h4, .markdown-section strong
   color #2c3e50