Working on PPC...

1 files changed, 29 insertions, 0 deletions

diff --git a/Software/Visual_Studio/Tango.SharedUI/Controls/NavigationControl.cs b/Software/Visual_Studio/Tango.SharedUI/Controls/NavigationControl.cs
index 72e7e50c8..b6f582594 100644
--- a/Software/Visual_Studio/Tango.SharedUI/Controls/NavigationControl.cs
+++ b/Software/Visual_Studio/Tango.SharedUI/Controls/NavigationControl.cs
@@ -144,6 +144,26 @@ namespace Tango.SharedUI.Controls
 
         #endregion
 
+        #region INavigationViewModel
+
+        /// <summary>
+        /// Represents a view data context which can be notified when its view is being navigated in or out.
+        /// </summary>
+        public interface INavigationViewModel
+        {
+            /// <summary>
+            /// Called when the navigation system has navigated to this VM view.
+            /// </summary>
+            void OnNavigatedTo();
+
+            /// <summary>
+            /// Called when the navigation system has navigated from this VM view.
+            /// </summary>
+            void OnNavigatedFrom();
+        }
+
+        #endregion
+
         private Grid _grid;
         private bool _loaded;
 
@@ -347,6 +367,12 @@ namespace Tango.SharedUI.Controls
                     {
                         navigationView.OnNavigated();
                     }
+
+                    INavigationViewModel toVM = toElement.Element.DataContext as INavigationViewModel;
+                    INavigationViewModel fromVM = toElement.Element.DataContext as INavigationViewModel;
+
+                    if (toVM != null) toVM.OnNavigatedTo();
+                    if (fromVM != null && fromVM != toVM) fromVM.OnNavigatedFrom();
                 };
 
                 switch (TransitionType)
@@ -421,6 +447,9 @@ namespace Tango.SharedUI.Controls
             {
                 toElement.Activate();
                 toElement.Reset();
+
+                INavigationViewModel toVM = toElement.Element.DataContext as INavigationViewModel;
+                if (toVM != null) toVM.OnNavigatedTo();
             }
         }