Code

void OnDiagramAddRow(object sender, EventArgs e)
{
	diagram.ExecuteCommand(
		new AddGridRowCmd(diagram, "row"));
}

class AddGridRowCmd : Command
{
	public AddGridRowCmd(Diagram diagram, string title) : base("Add grid row")
	{
		this.diagram = diagram;
		this.title = title;
	}

	protected override void Execute(bool undoEnabled)
	{
		header = new Header(title);
		diagram.LaneGrid.RowHeaders.Add(header);
	}

	protected override void Undo()
	{
		diagram.LaneGrid.RowHeaders.Remove(header);
	}

	protected override void Redo()
	{
		diagram.LaneGrid.RowHeaders.Add(header);
	}

	Diagram diagram;
	string title;
	Header header;
}