Tabs redesigned, update url and can show counter.

Tabs have been redesigned and can now display a counter. This counter
can be set by emiting a "counter" event from the child.
Tabs read and set a ?tab={slug} query parameter when changing tab, when
loaded we check for this parameter to automatically select the correct
tab.

frontend/ui/Tabs.vue

@@ -1,51 +1,80 @@
 <template>
   <div>
-    <div class="tab-container">
-      <div
+    <nav class="tab-container">
+      <a
         class="tab"
         v-for="(tab, index) in tabs"
         :key="index"
         @click="changeTab(index)"
+        @keydown.enter="changeTab(index)"
+        tabindex="0"
         :class="chosenTab == index ? 'active' : null"
-      >{{ tab.name }}</div>
-    </div>
+      >
+        {{ tab.name }}
+
+        <span v-if="tab.counter" class="counter">{{ tab.counter }}</span>
+      </a>
+    </nav>
+
     <div class="tab-elements">
-      <component :is="tabs[chosenTab].component" />
+      <component :is="tabs[chosenTab].component" @counter="updateCounter" />
     </div>
   </div>
 </template>
 
 <script>
-import eventBus from "@/mixins/EventBus";
 export default {
   props: {
     tabs: {
       type: Array
-    },
-    active: {
-      type: Number,
-      default: 0
     }
   },
   beforeMount() {
-    this.chosenTab = this.active;
+    const url = location.href;
+
+    if (url.includes("tab=")) {
+      const tabParameter = url.split("tab=")[1];
+      const matchingSlug = this.tabs.findIndex(tab => tab.slug == tabParameter);
+      console.log("matchingSlug:", matchingSlug);
+      this.chosenTab = matchingSlug;
+    }
   },
   data() {
     return {
       chosenTab: 0
     };
   },
+  computed: {
+    activeTab() {
+      return this.tabs[this.chosenTab];
+    }
+  },
   methods: {
-    changeTab: function(num) {
+    changeTab(num) {
       this.chosenTab = num;
-      this.$emit("tabChange", num);
-      eventBus.$emit("tab-change");
+
+      let url = location.href;
+      const tabParameterIndex = url.indexOf("tab=");
+
+      if (tabParameterIndex > 0) {
+        url = url.split("tab=")[0] + `tab=${this.activeTab.slug}`;
+      } else {
+        url = url + `?tab=${this.activeTab.slug}`;
+      }
+
+      window.history.pushState({}, "", url);
+    },
+    updateCounter(val) {
+      this.activeTab.counter = val;
     }
   }
 };
 </script>
 
 <style lang="scss" scoped>
+@import "@/styles/variables.scss";
+@import "@/styles/media-queries.scss";
+
 h1 {
   text-align: center;
 }
@@ -54,28 +83,50 @@ h1 {
   display: flex;
   flex-direction: row;
   justify-content: center;
-  margin-top: 25px;
-  border-bottom: 1px solid #333333;
+  // margin-top: 25px;
+  border-bottom: 1px solid var(--underlinenav-text);
+
+  margin-top: 2rem;
+
+  @include mobile {
+    flex-direction: column;
+  }
 }
 
 .tab {
   cursor: pointer;
-  font-size: 1.2rem;
-  display: flex;
-  justify-content: center;
-  align-items: center;
-  padding: 20px;
-  margin: 0 15px;
-  border: 1px solid #333333;
-  border-top-left-radius: 5px;
-  border-top-right-radius: 5px;
-  background: #00000008;
-  border-bottom: 1px solid #333333;
-  margin-bottom: -1px;
+  font-size: 1.1rem;
+  padding: 8px 16px;
+  border-bottom: 2px solid transparent;
+  color: rgba($matte-text-color, 0.9);
 
   &.active {
-    border-bottom: 1px solid white;
+    color: $matte-text-color;
+    border-color: var(--underlinenav-text-active) !important;
     background: white;
+    font-weight: 600;
+  }
+
+  &:hover,
+  &:focus {
+    border-color: var(--underlinenav-text-hover);
+    outline: 0;
+  }
+
+  & .counter {
+    margin-left: 4px;
+    box-sizing: border-box;
+
+    display: inline-block;
+    min-width: 20px;
+    padding: 0 6px;
+    font-size: 14px;
+    font-weight: 600;
+    line-height: 18px;
+    text-align: center;
+    background-color: rgba(209, 213, 218, 0.5);
+    border: 1px solid transparent;
+    border-radius: 2em;
   }
 }
 </style>