Stunner - Conditional events

Add support for the following conditional events to the palette:

1. Start event
2. Boundary interrupting event
3. Boundary non-interrupting event
4. Catching event

As Aimee I want to add conditional events so that I can model a process flow which is waiting for conditions to be met.

Which options should be available?

• Business Rules - set ruleflow group?
• DMN ( does it make sense here? )

Implementation details & specification of the supported properties per event type:

Start event:
The start conditional event only apply for the "Top Level Process" and "Event Sub-Processes"

• Top Level Process:
  • Name:
  • Documentation:
  • Expression:
  • Language: only drools expressions are supported by the jbpm engine.
  • UI: event border is solid

• Event Sub-Process:
  • Name:
  • Documentation:
  • IsInterrupting: true/false (default value is true)
    This property is only available when the event is used in an Event Sub-Process.
  • Expression:
  • Language: only drools expressions are supported by the jbpm engine.
  • UI: event border is solid when IsInterrupting == true, and dashed when false.

Boundary interrupting/non-interrupting event:

• Name:
• Documentation:
• CancelActivity: true/false (default value is true)
  This property is only available when the event is docked into another node/activity.
• Expression:
• Language: only drools expressions are supported by the jbpm engine.
• UI: event border solid when IsInterrupting == true, and dashed when false

Catching event:

• Name:
• Documentation:
• Expression:
• Language: only drools expressions are supported by the jbpm engine.
• UI: event border is solid.

End and intermediate throwing version of the Conditional event not exists in the bpmn2 standard.