/// <summary>
        ///     Draw a Rectangle
        /// </summary>
        /// <param name="transition"></param>
        /// <autor>Thomas Meents, Krystian Zielonka</autor>
        private ExtendedThumb DrawTransition(Transition transition)
        {
            String name = transition.Name.Trim();
            ExtendedThumb transitionThumb = new ExtendedThumb
            {
                Name = "Transition",
                Width = Settings.Default.TransitionWidth,
                Height = Settings.Default.TransitionHeight
            };
            transitionThumb.Margin = new Thickness(-transitionThumb.Width/2, -transitionThumb.Height/2, 0, 0);
            transitionThumb.Template = GetTransitionTemplate();

            transitionThumb.ToolTip = name;

            transitionThumb.SetValue(ContentControl.ContentProperty, name);

            ContextMenu contextMenu = new ContextMenu();
            Label labelText = new Label {Content = name};
            contextMenu.Items.Add(labelText);
            transitionThumb.ContextMenu = contextMenu;

            return transitionThumb;
        }
        /// <summary>
        ///     Draw a Ellipse
        /// </summary>
        /// <param Name="myCanvas"></param>
        /// <param name="place"></param>
        /// <autor>Thomas Meents, Krystian Zielonka</autor>
        private ExtendedThumb DrawPlace(Place place)
        {
            String name = place.Name.Trim();
            ExtendedThumb placeThumb = new ExtendedThumb
            {
                Name = "Place",
                Width = Settings.Default.PlaceRadius,
                Height = Settings.Default.PlaceRadius
            };
            placeThumb.Margin = new Thickness(-placeThumb.Width/2);
            placeThumb.Template = GetPlaceTemplate();
            placeThumb.SetValue(ContentControl.ContentProperty, name);
            placeThumb.InternName = place.ToString();

            return placeThumb;
        }