Class Condition

All Implemented Interfaces:
NamedObjectOps
Direct Known Subclasses:
BooleanCondition, DoubleCondition, IntegerCondition, LongCondition

Top-level basic-simulation condition class. Conditions represent quantities that are part of the global state of a simulation, but that are not represented by actors or other more specific simulation objects. Domains and user-defined condition observers will be notified when a condition changes.

Conditions can be used for a variety of purposes, including turning on or off debugging for all the actors associated with a given domain. The simplest conditions simply provide a value.

When a condition changes its state, the object that changed the state is expected to call notifyObservers() followed by completeNotification(). The use of two methods allows objects to queue up multiple notifications and apply them at once.

As a general rule, it is preferable to send as few notifications as possible. For example, if a condition represents a value that is changing with time, one might represent the condition by a value at some time and the rate of change, sending notifications only when new values or rates of change are needed.

  • Constructor Details

    • Condition

      protected Condition(DramaSimulation sim, String name, boolean intern) throws IllegalArgumentException
      Constructor.
      Parameters:
      sim - the simulation
      name - the name of the condition; null for an automatically generated name
      intern - true if the object can be looked up by using the methods in Simulation; false otherwise.
      Throws:
      IllegalArgumentException - typically means a name is already in use
  • Method Details

    • clone

      protected Object clone() throws CloneNotSupportedException
      Creates and returns a copy of this object. This method will throw the exception CloneNotSupportedException if the object is interned.
      Overrides:
      clone in class Object
      Throws:
      CloneNotSupportedException - a clone could not be created
      See Also:
    • isInterned

      public boolean isInterned()
      Determine if an object is interned in a object namer's tables.
      Specified by:
      isInterned in interface NamedObjectOps
      Returns:
      true if the object is interned; false if not
    • getObjectNamer

      protected Simulation getObjectNamer()
      Get the object namer for a named object.
      Returns:
      the object namer for this named object
    • getName

      public final String getName()
      Get an object's name.
      Specified by:
      getName in interface NamedObjectOps
      Returns:
      the name of the object
    • canDelete

      public boolean canDelete()
      Determine if this named object can be deleted. A named object can be deleted if the method delete has not been called and if the object is not in a state that prevents the object from being deleted. Subclasses that override this method must call canDelete() for their superclasses and return false if the superclass' canDelete method returns false. The default method returns true if delete() has not been called and returned true.
      Specified by:
      canDelete in interface NamedObjectOps
      Returns:
      true if this object can be deleted; false otherwise
    • delete

      public final boolean delete()
      Delete an object. An object can only be deleted once. If this method returns true, the object (if interned) will have been removed from the object namer tables.

      The implementations provided by DefaultNamedObect and generated because of a @NamedObject annotation provide a protected method named onDelete. A subclass that overrides onDelete() must call the onDelete method of its superclass after it's onDelete method has been called and any cleanup actions performed. In some cases, this may happen at a later time (e.g., if a thread is used for some of the cleanup operations or if it is otherwise necessary to wait).

      Specified by:
      delete in interface NamedObjectOps
      Returns:
      true if the deletion request was accepted; false otherwise
    • isDeleted

      public final boolean isDeleted()
      Determine if an object has been deleted. An object is deleted if the method delete() has been called and returned true.
      Specified by:
      isDeleted in interface NamedObjectOps
      Returns:
      true if deleted; false otherwise
    • deletePending

      public final boolean deletePending()
      Determine if an object is being deleted. An deletion is pending if the method delete() has been called and returned true but the deletion has not been completed.
      Specified by:
      deletePending in interface NamedObjectOps
      Returns:
      true if deletion is pending; false otherwise