private void BtnPreview_Click(object sender, RoutedEventArgs e)
 {
     preview = new WindowPreview(manager.ConvertToBlocks(extension), compiler.References)
     {
         Owner = this
     };
     preview.ShowDialog();
 }
        private void BtnCancel_Click(object sender, RoutedEventArgs e)
        {
            TextTitle.Clear();
            TextAuthor.Clear();
            TextSummary.Clear();

            preview   = null;
            manager   = null;
            extension = null;
            compiler  = null;

            StackResult.Visibility = Visibility.Collapsed;
            StackOpen.Visibility   = Visibility.Visible;
        }