State Transition Diagram Editor

A State Transition Diagram shows the dynamic behaviour of the Class. The State Transition Diagram is made up of States, Transitions between States, Events and Actions. You can switch to the State Transition Editor by selecting the Class in the Class Selector, the Class Editor or in the Class in the Class Diagram Editor.

An Event causes a change of state (a Transition) and may also cause an Action. An Event is an Operation of the Class or a visible Operation of the base Classes. An Action is an Operation of the Class or a visible Operation of the associated or base Classes. When you add an Event or Action to the diagram you can choose the name of the Operation from the list of available Operations.

The list of available Operations is determined by the relationships between the Classes in the parent diagram. For example, suppose you are drawing the State Transition Diagram of a Class SubClass belonging to Subsystem SUB. The relationships to the Class SubClass in the diagram of SUB determine the Operations available to SubClass. Suppose that BaseClass is a generalization of SubClass and that SubClass has an Association to AssClass and an Aggregation to AggClass.

The Events of SubClass can be any of the Operations of Subclass and any of the public or protected Operations of BaseClass.

The Actions of SubClass can be any of the Operations of Subclass and any of the public or protected Operations of BaseClass, and any of the public Operations of AssClass and AggClass.

You can also type the name of the Event or Action directly rather than choosing the name of the Operation from the list. If the Operation does not yet exist you should define it using the Edit Class command on the Event or Action. If you analyze the State Transition Diagram, the analyzer will supply a list of undefined or inaccessible operations.

Pull-down Menus

The State Transition Diagram editor has the following pull-down menus:

File

Edit

View

Draw

Options

Popup Menus

There are also popup menus available within the State Transition Diagram editor. These are activated by pressing the right mouse button. A different menu appears depending on the pointer position, relevant to the operations that are appropriate to the currently selected object and pointer position. There is a different menu for when you are:

pointing to a State

pointing to a Transition

pointing to Text

pointing to an Event

pointing to an Action

pointing within a selection frame

not pointing to a diagram object

In the last situation, ProMod-PLUS assumes that you want to Create an object.

Double-click on graphical objects

If you double-click on a graphical object this carries out the most commonly used command. The command started is different if you double-click on the label of an object or on the symbol excluding the label. For example, if you double-click on the name of a State this carries out Alter on the State name. If you double-click on the State symbol outside the State name this carries out Connect.

The following table shows the full list of commands carried out when double-clicking on objects.

Symbol

Label

State Connect Alter
Transition Add Event Alter
Text --- Alter