The HLU library has a hierarchical class structure . It starts with the Base class as the highest node. All classes are subclassed from the Base class. Some of the more important nodes on this hierarchical tree are the View class and the Workstation class , plus the App class , DataItem class , Error class, PlotManager class , and AnnoManager class . First, let's examine a bit more about how classes can interact in the HLU library.
Subclasses are classes that are derived from another class.
For example, TextItem is an immediate subclass of the View class. This means that TextItem is directly below View in the class hierarchy. Therefore, View is also an immediate superclass of TextItem. Objects of a subclass are also valid objects of classes higher in the hierarchy. Any XyPlot object inherits the resources of all of these superclasses.