Add RenewContext

Elwig/Windows/ContextWindow.cs

@@ -1,19 +1,43 @@
 using Elwig.Helpers;
 using System;
+using System.Threading.Tasks;
 using System.Windows;
+using System.Windows.Threading;
 
 namespace Elwig.Windows {
     public abstract class ContextWindow : Window {
 
-        protected readonly AppDbContext Context;
+        protected AppDbContext Context { get; private set; }
+        protected bool LockContext { get; set; } = false;
+
+        private readonly DispatcherTimer ContextRenewTimer;
+        private static readonly int ContextRenewSec = 10;
 
         public ContextWindow() : base() {
+            ContextRenewTimer = new DispatcherTimer();
+            ContextRenewTimer.Tick += new EventHandler(OnRenewContext);
+            ContextRenewTimer.Interval = new TimeSpan(0, 0, ContextRenewSec);
+            ContextRenewTimer.Start();
             Context = new();
+            Loaded += OnLoaded;
+        }
+
+        private void OnRenewContext(object? sender, EventArgs evt) {
+            if (LockContext || !Context.HasBackendChanged) return;
+            Context.Dispose();
+            Context = new();
+            RenewContext();
+        }
+
+        private void OnLoaded(object sender, RoutedEventArgs evt) {
+            RenewContext();
         }
 
         protected override void OnClosed(EventArgs evt) {
             base.OnClosed(evt);
             Context.Dispose();
         }
+
+        abstract protected Task RenewContext();
     }
 }