protected override void OnPreviewGotKeyboardFocus( KeyboardFocusChangedEventArgs e )
{
base.OnPreviewGotKeyboardFocus( e );
if( this.AutoSelectBehavior == AutoSelectBehavior.OnFocus )
{
// If the focus was not in one of our child ( or popup ), we select all the text.
if( !TreeHelper.IsDescendantOf( e.OldFocus as DependencyObject, this ) )
{
this.SelectAll();
}
}
}