//
// RemoteDataReferenceImpl.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.*;

/**
   RemoteDataReferenceImpl is VisAD remote adapter for DataReferenceImpl.

*/
public class RemoteDataReferenceImpl extends RemoteThingReferenceImpl
       implements RemoteDataReference {

  /**
   * construct a RemoteDataReferenceImpl adapting the given
   * DataReferenceImpl
   * @param ref adpted DataReferenceImpl
   * @throws RemoteException an RMI error occurred
   */
  public RemoteDataReferenceImpl(DataReferenceImpl ref)
         throws RemoteException {
    super(ref);
  }

  /**
   * set this RemoteDataReferenceImpl to refer to given Data
   * @param d Data to be set (must be RemoteDataImpl)
   * @throws VisADException a VisAD error occurred
   * @throws RemoteException an RMI error occurred
   */
  public synchronized void setData(Data d)
         throws VisADException, RemoteException {
    if (d == null) {
      throw new ReferenceException("RemoteDataReferenceImpl: data " +
                                   "cannot be null");
    }
    if (AdaptedThingReference == null) {
      throw new RemoteVisADException("RemoteDataReferenceImpl.setData: " +
                                     "AdaptedThingReference is null");
    }
    if (d instanceof DataImpl) {
      // allow Data object passed by copy from remote JVM
      ((DataReferenceImpl) AdaptedThingReference).setData(d);
    }
    else {
      ((DataReferenceImpl) AdaptedThingReference).adaptedSetData((RemoteData) d,
                                          (RemoteDataReference) this);
    }
  }

  /**
   * return referenced Data object, but if Data is a FieldImpl
   * return a RemoteFieldImpl referencing Data to avoid copying
   * entire FieldImpl between JVMs
   * @return referenced Data object, or null if none
   * @throws VisADException a VisAD error occurred
   * @throws RemoteException an RMI error occurred
   */
  public Data getData() throws VisADException, RemoteException {
    if (AdaptedThingReference == null) {
      throw new RemoteVisADException("RemoteDataReferenceImpl.getData: " +
                                     "AdaptedThingReference is null");
    }
    Data data = ((DataReferenceImpl) AdaptedThingReference).getData();
    if (data instanceof FieldImpl) {
      // decide here whether to return copy of remote reference
      boolean return_copy = false;
      if (return_copy) {
        return data;
      }
      else {
        return new RemoteFieldImpl((FieldImpl) data);
      }
    }
    else {
      return data;
    }
  }

  /**
   * this is more efficient than getData().getType() for
   * RemoteDataReferences
   * @return the MathType of referenced Data object, or null if none;
   * @throws VisADException a VisAD error occurred
   * @throws RemoteException an RMI error occurred
   */
  public MathType getType() throws VisADException, RemoteException {
    if (AdaptedThingReference == null) {
      throw new RemoteVisADException("RemoteDataReferenceImpl.getType: " +
                                     "AdaptedThingReference is null");
    }
    return ((DataReferenceImpl) AdaptedThingReference).getData().getType();
  }

}