[a11y][WPF] Fixed combo box item automation names

This fixes https://devdiv.visualstudio.com/DevDiv/_workitems/edit/596863.
Previously, we showed Xwt.WPFBackend.ValueConverter (the class name) as the
automation Name for combo box items, but now properly show the item text as
the Name.

At first, I tried replacing the default ComboBox and ComboBoxItem automation peers,
but there was a fair amount of complexity around that, making the pair of peers
properly work together. In the end, overriding ToString turned out to be a much
simpler and safer fix.

1 files changed, 12 insertions, 1 deletions

diff --git a/Xwt.WPF/Xwt.WPFBackend/ValuesContainer.cs b/Xwt.WPF/Xwt.WPFBackend/ValuesContainer.cs
index 9380d274..a2d4fd37 100644
--- a/Xwt.WPF/Xwt.WPFBackend/ValuesContainer.cs
+++ b/Xwt.WPF/Xwt.WPFBackend/ValuesContainer.cs
@@ -1,4 +1,4 @@
-//
+//
 // ValuesContainer.cs
 //
 // Author:
@@ -67,5 +67,16 @@ namespace Xwt.WPFBackend
 			if (handler != null)
 				handler (this, e);
 		}
+
+		/// <summary>
+		/// ToString is used by the default ComboBoxItem automation peer to get the automation Name for the item.
+		/// Normally, we want to be the same as the text in the combo, the first value.
+		/// </summary>
+		public override string ToString ()
+		{
+			if (values.Length > 0 && values[0] is string)
+				return (string) values[0];
+			else return base.ToString ();
+		}
 	}
 }