Selection Object (Visio)
Represents a subset of Shape objects for a page or master to which an operation can be applied.
To retrieve a Selection object that corresponds to the set of shapes selected in a window, use the Selection property of a Window object.
The default property of a Selection object is Item.
After you retrieve a Selection object, you can add or remove shapes by using the Select method.
By default, the items reported by a Selection object do not include subselected or superselected Shape objects. Use the IterationMode property to control whether subselected and superselected Shape objects are reported. You can determine whether an individual item is subselected or superselected by using the ItemStatus property.