/// <summary>
        /// Creates an instance of the VisualPropertyPage and has it fills its content according to the
        /// current DrawingBoard and selected tool, effect, animation.
        /// </summary>
        public void Show(Engine.Workflow w)
        {
            if (t_visualPropertyPage != null)
            {
                t_docContent.Close -= Pane_Close;
                Grid g = (Grid)t_docContent.Content;
                g.Children.Remove(t_visualPropertyPage);
                t_visualPropertyPage = null;
                g = null;

                t_visualPropertyPage = new PaintualUI.Controls.PropertyPage.VisualPropertyPage();
                g                    = new Grid();
                g.Background         = Brushes.DarkGray;
                t_docContent.Content = g;
                g.Children.Add(t_visualPropertyPage);

                t_docContent.Close += Pane_Close;

                t_visualPropertyPage.Build(w);
                return;
            }

            t_visualPropertyPage = new PaintualUI.Controls.PropertyPage.VisualPropertyPage();

            if (t_docContent == null)
            {
                t_docContent = CreateContainer();
            }

            t_visualPropertyPage.Build(w);
        }
 private void Pane_Close(object sender, System.Windows.RoutedEventArgs e)
 {
     t_docContent = null;
 }