Connecting Classes

The relationship lines in the Diagram View represent parent child (inheritance) relationships. Each oval of a class has one square on either side, left and right or top and bottom, depending on the selected layout. These are what we call expanders and display as empty if there are no relationships from that expander, a + if the class relationships are not shown and a - if the classes are all shown.

The expanders can be dragged and dropped from one class to another to create new relationships. Dragging the expander from the left or bottom of a class will make the class you drop the expander on a parent of the class you started from. Dragging the right or top expander onto another class will make the class you drop the expander on a child of the class you started from.

A class cannot be set as a child of a drawing class. If an attempt is made to set a class as the child of a drawing class, an error message is displayed summarizing the problem.