public void AddNewType(ClassViewModel type)
{
if (!this.Types.Contains(type))
this.Types.Add(type);
}
/// <summary>
/// Adds new (dropped) item to diagram.
/// </summary>
/// <param name="classViewModel">The model (representing a type) to be added.</param>
/// <param name="point">The position.</param>
/// <param name="offset">The displacement.</param>
private void AddNewItemToDiagram(ClassViewModel classViewModel, Point point, ref int offset)
{
if (this.DataContext == null || !(this.DataContext is MainViewModel)) return;
classViewModel.Position = new Point(point.X + ((offset % 5) * 200), point.Y + ((offset / 5) * 200));
(this.DataContext as MainViewModel).ClassDiagramGraphSource.AddItem(classViewModel);
offset++;
}