//
// Action.java
//

/*
VisAD system for interactive analysis and visualization of numerical
data.  Copyright (C) 1996 - 2017 Bill Hibbard, Curtis Rueden, Tom
Rink, Dave Glowacki, Steve Emmerson, Tom Whittaker, Don Murray, and
Tommy Jasmin.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA
*/

package visad;

import java.rmi.RemoteException;

/**
   Action is the VisAD interface for runnable threads that need to be
   notified when ThingReference objects change.  For example, this may
   be used for a Data display or for a spreadsheet cell.

*/
public interface Action extends ThingChangedListener {

  /**
   * Creates a link to a ThingReference.  Note that this method causes this
   * object to register itself with the ThingReference.
   * @param ref                   The ThingReference to which to create
   *                              the link.  Subsequent invocation of
   *                              thingChanged(ThingChangedEvent)
   *                              causes invocation of
   *                              ref.acknowledgeThingChanged(this)
   *                              .  This method invokes 
   *                              ref.addThingChangedListener(this, ...).
   * @throws RemoteVisADException if the reference isn't a {@link
   *                              ThingReferenceImpl}.
   * @throws ReferenceException   if the reference has already been added.
   * @throws VisADException       if a VisAD failure occurs.
   * @throws RemoteException      if a Java RMI failure occurs.
   * @see #thingChanged(ThingChangedEvent)
   * @see ThingReference#addThingChangedListener(ThingChangedListener, long)
   */
  void addReference(ThingReference ref)
         throws VisADException, RemoteException;

  /**
   * 
Removes a link to a ThingReference.
   *
   * @param ref                   The reference to be removed.
   * @throws RemoteVisADException if the reference isn't a {@link
   *                              ThingReferenceImpl}.
   * @throws ReferenceException   if the reference isn't a part of this
   *                              instance.
   * @throws VisADException       if a VisAD failure occurs.
   * @throws RemoteException      if a Java RMI failure occurs.
   */
  void removeReference(ThingReference ref)
         throws VisADException, RemoteException;

  /**
    * delete all links to ThingReferences
    */
  void removeAllReferences()
         throws VisADException, RemoteException;

  /**
    * @return String name of this Action
    */
  String getName()
         throws VisADException, RemoteException;

}