private static void textChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            AutoLengthTextBlock t = (AutoLengthTextBlock)d;

            t.FullText = (String)e.NewValue;
            t.setText();
        }
        private static void TextAlignmentChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            AutoLengthTextBlock t = (AutoLengthTextBlock)d;

            t.textBlock.TextAlignment = (TextAlignment)e.NewValue;
        }