feat: nav dropdown (#51)

* feat: add external link support for nav items

* feat: support nav dropdown

Co-authored-by: Kia Ishii <kia.king.08@gmail.com>
Co-authored-by: Evan You <yyx990803@gmail.com>

src/client/theme-default/components/NavBar.ts

@@ -1,10 +1,12 @@
 import { computed } from 'vue'
 import { useSiteData } from 'vitepress'
 import NavBarLink from './NavBarLink.vue'
+import NavDropdownLink from './NavDropdownLink.vue'
 
 export default {
   components: {
-    NavBarLink
+    NavBarLink,
+    NavDropdownLink
   },
 
   setup() {

src/client/theme-default/components/NavBar.vue

@@ -13,11 +13,10 @@
     <span>{{ $site.title }}</span>
   </a>
   <nav class="nav-links" v-if="navData">
-    <NavBarLink
-      v-for="item of navData"
-      :key="item.link"
-      :item="item"
-    />
+    <template v-for="item of navData">
+      <NavDropdownLink v-if='item.items' :item="item"/>
+      <NavBarLink v-else :item="item"/>
+    </template>
   </nav>
 </template>
 

src/client/theme-default/components/NavDropdownLink.ts

@@ -0,0 +1,42 @@
+import NavBarLink from './NavBarLink.vue'
+import { defineComponent, ref, watch, PropType } from 'vue'
+import { useRoute } from 'vitepress'
+import { DefaultTheme } from '../config'
+
+export default defineComponent({
+  name: 'DropdownLink',
+  components: {
+    NavBarLink
+  },
+  props: {
+    item: {
+      type: Object as PropType<DefaultTheme.NavItemWithChildren>,
+      required: true
+    }
+  },
+  setup(props) {
+    const open = ref(false)
+    const route = useRoute()
+
+    watch(
+      () => route.path,
+      () => {
+        open.value = false
+      }
+    )
+
+    const setOpen = (value: boolean) => {
+      open.value = value
+    }
+
+    const isLastItemOfArray = <T>(item: T, array: T[]) => {
+      return array.length && array.indexOf(item) === array.length - 1
+    }
+
+    return {
+      open,
+      setOpen,
+      isLastItemOfArray
+    }
+  }
+})

src/client/theme-default/components/NavDropdownLink.vue

@@ -0,0 +1,161 @@
+<template>
+  <div class="dropdown-wrapper" :class="{ open }">
+    <button
+      class="dropdown-title"
+      type="button"
+      :aria-label="item.ariaLabel"
+      @click="setOpen(!open)"
+    >
+      <span>{{ item.text }}</span>
+      <span class="arrow" :class="open ? 'down' : 'right'" />
+    </button>
+
+    <ul v-show="open" class="nav-dropdown">
+      <li v-for="(subItem, index) in item.items" :key="subItem.link || index" class="dropdown-item">
+        <h4 v-if="subItem.items">{{ subItem.text }}</h4>
+        <ul v-if="subItem.items" class="dropdown-subitem-wrapper">
+          <li
+            v-for="childSubItem in subItem.items"
+            :key="childSubItem.link"
+            class="dropdown-subitem"
+          >
+            <NavBarLink
+              :item="childSubItem"
+              @focusout="
+                  isLastItemOfArray(childSubItem, subItem.items) &&
+                    isLastItemOfArray(subItem, item.items) &&
+                    setOpen(false)
+                "
+            />
+          </li>
+        </ul>
+
+        <NavBarLink
+          v-else
+          :item="subItem"
+          @focusout="isLastItemOfArray(subItem, item.items) && setOpen(false)"
+        />
+      </li>
+    </ul>
+  </div>
+</template>
+
+<script src="./NavDropdownLink"></script>
+
+<style>
+.dropdown-wrapper {
+  position: relative;
+  cursor: pointer;
+  display: inline-block;
+  margin-left: 1.5rem;
+}
+.dropdown-wrapper .dropdown-title {
+  font: inherit;
+  color: var(--text-color);
+  font-weight: 600;
+  display: inline-block;
+  height: 1.75rem;
+  line-height: 1.75rem;
+  padding: inherit;
+  background: transparent;
+  border: none;
+}
+.dropdown-wrapper .dropdown-title:hover {
+  border-color: transparent;
+}
+
+.dropdown-wrapper .dropdown-title .arrow {
+  display: inline-block;
+  vertical-align: middle;
+  margin-top: -1px;
+  margin-left: 0.4rem;
+}
+
+.dropdown-wrapper .nav-dropdown .dropdown-item {
+  color: inherit;
+  line-height: 1.7rem;
+}
+.dropdown-wrapper .nav-dropdown .dropdown-item h4 {
+  margin: 0.45rem 0 0;
+  border-top: 1px solid #eee;
+  padding: 0.45rem 1.5rem 0 1.25rem;
+}
+.dropdown-wrapper .nav-dropdown .dropdown-item .dropdown-subitem-wrapper {
+  padding: 0;
+  list-style: none;
+}
+.dropdown-wrapper
+  .nav-dropdown
+  .dropdown-item
+  .dropdown-subitem-wrapper
+  .dropdown-subitem {
+  font-size: 0.9em;
+}
+.dropdown-wrapper .nav-dropdown .dropdown-item a {
+  display: block;
+  line-height: 1.7rem;
+  position: relative;
+  border-bottom: none;
+  font-weight: 400;
+  margin-bottom: 0;
+  margin-left: 0;
+  padding: 0 1.5rem 0 1.25rem;
+}
+.dropdown-wrapper .nav-dropdown .dropdown-item a:hover {
+  color: var(--accent-color);
+}
+.dropdown-wrapper .nav-dropdown .dropdown-item a.active {
+  color: var(--accent-color);
+}
+.dropdown-wrapper .nav-dropdown .dropdown-item a.active::after {
+  content: '';
+  width: 0;
+  height: 0;
+  border-left: 5px solid var(--accent-color);
+  border-top: 3px solid transparent;
+  border-bottom: 3px solid transparent;
+  position: absolute;
+  top: calc(50% - 2px);
+  left: 9px;
+}
+.dropdown-wrapper .nav-dropdown .dropdown-item:first-child h4 {
+  margin-top: 0;
+  padding-top: 0;
+  border-top: 0;
+}
+
+.dropdown-wrapper {
+  height: 1.8rem;
+}
+.dropdown-wrapper:hover .nav-dropdown,
+.dropdown-wrapper.open .nav-dropdown {
+  display: block !important;
+}
+.dropdown-wrapper.open:blur {
+  display: none;
+}
+.dropdown-wrapper .dropdown-title .arrow {
+  border-left: 4px solid transparent;
+  border-right: 4px solid transparent;
+  border-top: 6px solid #aaa;
+  border-bottom: 0;
+}
+.dropdown-wrapper .nav-dropdown {
+  display: none;
+  height: auto !important;
+  box-sizing: border-box;
+  max-height: calc(100vh - 2.7rem);
+  overflow-y: auto;
+  position: absolute;
+  top: 100%;
+  right: 0;
+  background-color: #fff;
+  padding: 0.6rem 0;
+  border: 1px solid #ddd;
+  border-bottom-color: #ccc;
+  text-align: left;
+  border-radius: 0.25rem;
+  white-space: nowrap;
+  margin: 0;
+}
+</style>