You can add a state with default history to save the current
status of your state machine in situations where a separate control
sequence is required to handle a certain event. When the external
sequence concludes, control returns to the default history state.
About this task
The history of a state is represented by the substate
that was previously active before the current state became active.
Deep history implies that control will return to any state at all
hierarchy levels.
You must have a state machine diagram open
that contains a substate with a region inside.
To create a default
history state:
Procedure
- In the Palette, under Capsule
State Machine, click Deep History.
- Click in the region of the substate that will contain the
default history point.
- Draw a transition from the history point to the desired
default state.
Note: If you do not specify a desired default
state, the initial state is used. However, this will not be explicitly
shown because UML 2.0 does not allow for incoming transitions into
initial states.