show activity indicator while still loading

src/App/Pages/BaseContentPage.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Threading.Tasks;
+using Xamarin.Forms;
+
+namespace Bit.App.Pages
+{
+    public class BaseContentPage : ContentPage
+    {
+        protected void SetActivityIndicator()
+        {
+            Content = new ActivityIndicator
+            {
+                IsRunning = true,
+                VerticalOptions = LayoutOptions.CenterAndExpand,
+                HorizontalOptions = LayoutOptions.Center
+            };
+        }
+
+        protected async Task LoadOnAppearedAsync(View viewToSet, bool fromModal, Func<Task> workFunction)
+        {
+            async Task LoadAsync()
+            {
+                await workFunction.Invoke();
+                if(viewToSet != null)
+                {
+                    Content = viewToSet;
+                }
+            }
+            if(Device.RuntimePlatform == Device.iOS)
+            {
+                await LoadAsync();
+                return;
+            }
+            await Task.Run(async () =>
+            {
+                await Task.Delay(fromModal ? 400 : 200);
+                Device.BeginInvokeOnMainThread(async () => await LoadAsync());
+            });
+        }
+    }
+}