Fixed scrolling to top on submission change

Introducing the two pane layout component broke it.

frontend/src/components/TwoPaneLayout.vue

@@ -3,7 +3,10 @@
     class="pane-wrapper"
     no-gutters
   >
-    <v-col class="pane">
+    <v-col
+      ref="leftPane"
+      class="pane"
+    >
       <slot name="left" />
     </v-col>
     <v-divider
@@ -12,6 +15,7 @@
     />
     <v-col
       v-if="showRightPane"
+      ref="rightPane"
       class="pane"
     >
       <slot name="right" />
@@ -25,6 +29,14 @@ import { Vue, Component, Prop } from 'vue-property-decorator'
 @Component
 export default class TwoPaneLayout extends Vue {
   @Prop({ type: Boolean, default: true }) showRightPane!: boolean
+
+  leftPane(): HTMLElement {
+    return this.$refs.leftPane as HTMLElement
+  }
+
+  rightPane(): HTMLElement {
+    return this.$refs.rightPane as HTMLElement
+  }
 }
 </script>
 

frontend/src/pages/SubscriptionWorkPage.vue

 <template>
-  <two-pane-layout :show-right-pane="showSubmissionType">
+  <two-pane-layout
+    ref="layout"
+    :show-right-pane="showSubmissionType"
+  >
     <template #left>
       <v-container>
         <route-change-confirmation :next-route="nextRoute" />
@@ -58,6 +61,9 @@ const onRouteEnterOrUpdate: NavigationGuard =  function (to, from, next) {
   }
 })
 export default class SubscriptionWorkPage extends Vue {
+  $refs!: {
+    layout: TwoPaneLayout
+  }
 
   subscriptionActive = false
   nextRoute = () => {}
@@ -112,7 +118,7 @@ export default class SubscriptionWorkPage extends Vue {
 
   @Watch('currentAssignment')
   onCurrentAssignmentChanged() {
-    window.scrollTo(0, 0)
+    this.$refs.layout.leftPane().scrollTop = 0
   }
 }
 </script>