An event is an observable occurrence. In the UML
metamodel it is a child of
There are a number of different types of events that are children of event within the UML metamodel.
CallEvent. Associated with an
operation of a class, this event is caused by a call to the
given operation. The expected effect is that the steps of
the operation will be executed.
SignalEvent. Associated with a
signal, this event is caused by the signal being
TimeEvent. An event cause by
expiration of a timing deadline.
ChangeEvent. An event caused by a
particular expression (of attributes and associations)
An event is represented by its name.
The details tabs that are active for events are as follows.
In the UML metamodel, an
Event has the following standard
create (for a
Create is a stereotyped call event denoting
that the instance receiving that event
has just been created.
For state machines,
it triggers the initial transition
at the topmost level of the state machine
(and is the only kind of trigger
that may be applied to an initial transition).
destroy (for a
Destroy is a stereotyped call event denoting
that the instance receiving the event
is being destroyed.
Standard tab. In the UML metamodel, an
Event has no standard tagged
Navigate up through the composition structure.
This creates a new Stereotype (see Section 16.6, “ Stereotype ”) for the selected event, navigating immediately to the properties tab for that stereotype.
This creates a new parameter for the event operation as the current parameter, navigating immediately to the properties tab for that parameter (see Section 18.9, “ Parameter ”).
This deletes the event from the model.
Text box. The name of the event. By convention event names start with a lower case letter and use bumpy caps to divide words within the name in the same way as operations.
ArgoUML does not enforce this naming convention.
For call events it makes sense to use the name
of the associated operation. For signal events it
make sense to use the name of the signal, prefixed by
Text field. Shows the namespace for the event. This is the composition hierarchy.
Text area, with entries for all the actual parameter values of the event (see Section 18.9, “ Parameter ”).
Button 1 double-click on any of the parameters navigates to that parameter, button 2 click brings up a pop up menu with one entry.
New Parameter. Create a
new parameter and navigate to it.
This shows the transition caused by the event.
button 1 double-click on the transition navigates to that transition.
Drop-down selector. Only present for a Call Event. This allows specifying the operation that causes the event when called.
Text field. Only present for a Signal Event. This allows specifying the signal that causes the event when called.
Button 1 double-click navigates to the selected signal, button 2 gives a pop up menu with two entries.
opens a dialog box that allows selecting
an already existing signal.
New Signal. Creates
a new Signal, and navigates to it.
Double text field. Only present for a Time Event. This allows expressing the time that the event is called.
The first of the two fields is for the body of the expression, and the second one for the language in which it is written.
In ArgoUML V0.20, the properties panel of a change event lacks a field to enter the change expression.