Fixed NullableBoolEditor: the editor must be able to show the difference between the null value and an ambiguous value (multiple selected components with different values).

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@2672 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/Controls/TypeEditors/NullableBoolEditor.cs

@@ -14,37 +14,42 @@ namespace ICSharpCode.WpfDesign.Designer.Controls.TypeEditors
 	[TypeEditor(typeof(bool?))]
 	public class NullableBoolEditor : ComboBox
 	{
-		readonly static Entry[] entries = {
-			new Entry(SharedInstances.BoxedTrue, bool.TrueString),
-			new Entry(SharedInstances.BoxedFalse, bool.FalseString),
-			new Entry(null, "Null")
-		};
+		const string NullString = "Null";
 		
 		public NullableBoolEditor(IPropertyEditorDataProperty property)
 		{
-			this.SelectedValuePath = "Value";
-			this.ItemsSource = entries;
-			SetBinding(ComboBox.SelectedValueProperty, PropertyEditorBindingHelper.CreateBinding(this, property));
+			// the UI must show the difference between an ambiguous property value
+			// and null, so we use a combo box bound to a string property
+			property = new NullableBoolToStringProperty(property);
+			this.ItemsSource = new string[] { NullString, false.ToString(), true.ToString() };
+			SetBinding(ComboBox.SelectedItemProperty, PropertyEditorBindingHelper.CreateBinding(this, property));
 		}
 		
-		sealed class Entry
+		/// <summary>
+		/// views a bool? property as string property
+		/// </summary>
+		sealed class NullableBoolToStringProperty : ProxyPropertyEditorDataProperty
 		{
-			object val;
-			string description;
-			
-			public object Value {
-				get { return val; }
-			}
-			
-			public Entry(object val, string description)
+			public NullableBoolToStringProperty(IPropertyEditorDataProperty data)
+				: base(data)
 			{
-				this.val = val;
-				this.description = description;
 			}
 			
-			public override string ToString()
-			{
-				return description;
+			public override object Value {
+				get {
+					object v = base.Value;
+					if (v == null)
+						return IsAmbiguous ? null : NullString;
+					else
+						return v.ToString();
+				}
+				set {
+					string v = (string)value;
+					if (v == NullString)
+						base.Value = null;
+					else
+						base.Value = SharedInstances.Box(bool.Parse(v));
+				}
 			}
 		}
 	}