add rooter restore scroll state when using navigator return/next buttons

app/src/router/index.js

@@ -8,7 +8,23 @@ Vue.use(VueRouter)
 const router = new VueRouter({
   // mode: 'history', // this allow all routes to be real ones (without '#')
   base: process.env.BASE_URL,
-  routes
+  routes,
+
+  scrollBehavior (to, from, savedPosition) {
+    // Mimics the native scroll behavior of the browser.
+    // This allows the user to find his way back to the scroll level of the previous/next route.
+
+    // if animations are enabled, we need to delay a bit the returned value of the saved
+    // scroll state because the component probably hasn't updated the window height yet.
+    // Note: this will only work with routes that use stored data or that has static content
+    if (store.getters.transitions && savedPosition) {
+      return new Promise(resolve => {
+        setTimeout(() => resolve(savedPosition), 0)
+      })
+    } else {
+      return savedPosition || { x: 0, y: 0 }
+    }
+  }
 })
 
 router.beforeEach((to, from, next) => {
@@ -17,7 +33,6 @@ router.beforeEach((to, from, next) => {
     next()
   } else {
     store.dispatch('DISCONNECT', to)
-    // next({ name: 'login', query: { redirect: to.path } })
   }
 })