Resolved another threading issue with SynchronizedObservableCollection.

Related Work Items: #229

1 files changed, 55 insertions, 6 deletions

diff --git a/Software/Visual_Studio/Tango.Core/SynchronizedObservableCollection.cs b/Software/Visual_Studio/Tango.Core/SynchronizedObservableCollection.cs
index f0a13b3c9..b12c48ded 100644
--- a/Software/Visual_Studio/Tango.Core/SynchronizedObservableCollection.cs
+++ b/Software/Visual_Studio/Tango.Core/SynchronizedObservableCollection.cs
@@ -6,34 +6,83 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using System.Windows;
+using System.Windows.Data;
 using System.Windows.Threading;
 
 namespace Tango.Core
 {
     public class SynchronizedObservableCollection<T> : ObservableCollection<T>
     {
+        private static object _sync_lock = new object();
+        private static object _modify_lock = new object();
+
         public SynchronizedObservableCollection() : base()
         {
-            this.EnableCrossThreadOperations();
+            BindingOperations.EnableCollectionSynchronization(this, _sync_lock);
         }
 
         public SynchronizedObservableCollection(IEnumerable<T> collection) : base(collection)
         {
-
+            BindingOperations.EnableCollectionSynchronization(this, _sync_lock);
         }
 
         protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
         {
-            if (ObservableEntityCollectionSettings._dispatcher != null)
+            SynchronizedObservableCollectionDispatcher.Invoke(() =>
             {
-                ObservableEntityCollectionSettings._dispatcher.BeginInvoke(new Action(() =>
+                lock (_modify_lock)
                 {
                     base.OnCollectionChanged(e);
-                }));
+                }
+            });
+        }
+
+        protected override void InsertItem(int index, T item)
+        {
+            lock (_modify_lock)
+            {
+                base.InsertItem(index, item);
+            }
+        }
+
+        protected override void RemoveItem(int index)
+        {
+            lock (_modify_lock)
+            {
+                base.RemoveItem(index);
+            }
+        }
+
+        protected override void ClearItems()
+        {
+            lock (_modify_lock)
+            {
+                base.ClearItems();
+            }
+        }
+    }
+
+    internal static class SynchronizedObservableCollectionDispatcher
+    {
+        internal static Dispatcher Dispatcher { get; set; }
+
+        static SynchronizedObservableCollectionDispatcher()
+        {
+            if (Application.Current != null)
+            {
+                Dispatcher = Application.Current.Dispatcher;
+            }
+        }
+
+        internal static void Invoke(Action action)
+        {
+            if (Dispatcher != null)
+            {
+                Dispatcher.BeginInvoke(action);
             }
             else
             {
-                base.OnCollectionChanged(e);
+                action();
             }
         }
     }