made SeletedItem of templatedGroup writable

3 files changed, 23 insertions, 1 deletions

diff --git a/src/ExtensionsMethods.cs b/src/ExtensionsMethods.cs
index 6198dee6..6697be62 100644
--- a/src/ExtensionsMethods.cs
+++ b/src/ExtensionsMethods.cs
@@ -125,6 +125,14 @@ namespace Crow
 		{
 			return c == '\t' || c == '\r' || c == '\n' || char.IsWhiteSpace (c);
 		}
+		public static object GetDefaultValue(this object obj)
+		{			
+			Type t = obj.GetType ();
+			if (t.IsValueType)
+				return Activator.CreateInstance (t);
+			
+			return null;
+		}
 	}
 }
 
diff --git a/src/GraphicObjects/TemplatedGroup.cs b/src/GraphicObjects/TemplatedGroup.cs
index c32b2c44..34d57727 100644
--- a/src/GraphicObjects/TemplatedGroup.cs
+++ b/src/GraphicObjects/TemplatedGroup.cs
@@ -148,7 +148,18 @@ namespace Crow
 			}
 		}
 		[XmlIgnore]public virtual object SelectedItem{
-			get { return data == null ? null : _selectedIndex < 0 ? null : data[_selectedIndex]; }
+			get { return data == null ? null : _selectedIndex < 0 ? data.GetDefaultValue() : data[_selectedIndex]; }
+			set {
+				if (data == null) {
+					SelectedIndex = -1;
+					return;
+				}
+				//TODO:double check if value type will be notified to binding sys
+				if (value == SelectedItem)
+					return;
+				
+				SelectedIndex = data.IndexOf (value);
+			}
 		}
 		[XmlIgnore]public bool HasItems {
 			get { return Items.Count > 0; }
diff --git a/src/Instantiator.cs b/src/Instantiator.cs
index 297337ed..b3f070e7 100644
--- a/src/Instantiator.cs
+++ b/src/Instantiator.cs
@@ -890,6 +890,9 @@ namespace Crow.IML
 
 				CompilerServices.emitConvert (il, piSource.PropertyType);
 
+				if (!piSource.CanWrite)
+					throw new Exception ("Source member of bindind is read only:" + piSource.ToString());
+
 				il.Emit (OpCodes.Callvirt, piSource.GetSetMethod ());
 
 				il.MarkLabel (endMethod);