private static void OnIsSelectableChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
SearchableTextControl obj = d as SearchableTextControl;
obj.ResetSelectionTextRange();
obj.Cursor = obj.IsSelectable ? Cursors.IBeam : Cursors.Arrow;
}
/// <summary>
/// Create a call back function which is used to invalidate the rendering of the element,
/// and force a complete new layout pass.
/// One such advanced scenario is if you are creating a PropertyChangedCallback for a
/// dependency property that is not on a Freezable or FrameworkElement derived class that
/// still influences the layout when it changes.
/// </summary>
private static void UpdateControlCallBack(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
SearchableTextControl obj = d as SearchableTextControl;
obj.InvalidateVisual();
}