//  $Id: StructureComponentRelation.java,v 1.1 2006/05/20 17:02:06 Sasha Buzko Exp $
//
//  Copyright (c) 2000-2002  San Diego Supercomputer Center (SDSC),
//  a facility operated jointly by the University of California,
//  San Diego (UCSD) and General Atomics, San Diego, California, USA.
//
//  Users and possessors of this source code are hereby granted a
//  nonexclusive, royalty-free copyright and design patent license to
//  use this code in individual software.  License is not granted for
//  commercial resale, in whole or in part, without prior written
//  permission from SDSC.  This source is provided "AS IS" without express
//  or implied warranty of any kind.
//
//  For further information, please see:  http://mbt.sdsc.edu
//
//  History:
//  $Log: StructureComponentRelation.java,v $
//  Revision 1.1  2006/05/20 17:02:06  Sasha Buzko
//  Updated version
//
//  Revision 1.1  2006/04/30 20:14:05  Sasha Buzko
//  New version of the app
//
//  Revision 1.1  2006/04/15 19:42:27  Sasha Buzko
//  Initial commit
//
//  Revision 1.1  2005/11/13 04:35:26  Administrator
//  *** empty log message ***
//
//  Revision 1.2  2003/04/23 17:40:15  moreland
//  Removed StructureComponentID/scid and replaced it with a "structure" field
//  in the StructureComponent base class.
//  Changed "getType" method to "getStructureComponentType" to return dynamic
//  SC type (ie: class name).
//
//  Revision 1.1  2002/10/24 17:54:01  moreland
//  Provides implementation for the improved Structure API/implementation.
//
//  Revision 1.0  2002/09/24 23:38:39  moreland
//

package edu.sdsc.mbt;

/**
 *  A class used to store a single relationship description between two
 *  StructureComponent types (much like a relational link between
 *  tables in a database). This class is used by the StructureComponentRegistry
 *  to define the relationship model for StructureComponent objects.
 *  <P>
 *  For example, the Conformation type relates to Atom type by means
 *  of an implied reference between the Conformation class's start_residue
 *  and end_residue fields, and the Atom class's residue_id field. A
 *  Conformation object therfore "relates" to a set of Atom values.
 *  <P>
 *  @author John L. Moreland
 */
public abstract class StructureComponentRelation implements java.io.Serializable
{
	/**
	 * The name of this Relation
	 */
	private String name = null;
	private String subject_type = null;
	private String object_type = null;

	/**
	 * Constructor.
	 */
	public StructureComponentRelation( String name, String subject_type,
		String object_type )
	{
		this.name = name;
		this.subject_type = subject_type;
		this.object_type = object_type;
	}

	/**
	 * Returns the <I>name</I> of this StructureComponentRelation object.
	 */
	public final String getName()
	{
		return name;
	}

	/**
	 * Returns the <I>subject type</I> of this StructureComponentRelation
	 * object.
	 */
	public final String getSubjectType()
	{
		return subject_type;
	}

	/**
	 * Returns the <I>object type</I> of this StructureComponentRelation
	 * object.
	 */
	public final String getObjectType()
	{
		return object_type;
	}

	/**
	 * Tests to see if one StructureComponent instance is related to
	 * another. This method first checks to see if the subject and object
	 * types have a defined relation. Then a specific comparision to see
	 * if the instances are directly linked is performed by calling the
	 * abstract "isLinked" method.
	 * <P>
	 */
	public final boolean isRelated( StructureComponent subject,
		StructureComponent object )
	{
		// Are the subject and object related at all?
		if ( subject.getStructureComponentType() != subject_type )
			return false;
		if ( object.getStructureComponentType() != object_type )
			return false;

		// Are the subject and object linked?
		return isLinked( subject, object );
	}

	/**
	 * Tests to see if one StructureComponent instance is linked to
	 * another. This method is called by the parent class's "isRelated"
	 * method.
	 * <P>
	 * Example:
	 * <P>
	 * <PRE>
	 * StructureComponentRelation residue_relation =
	 *     new StructureComponentRelation( name, subject_type, object_type )
	 * {
	 *     abstract boolean isRelated( StructureComponent subject,
	 *         StructureComponent object )
	 *     {
	 *         // Cast the StructureComponent objects to the correct types.
	 *         Conformation conformation = (Conformation) subject;
	 *         Atom atom = (Atom) object;
	 *         
	 *         // Does the Atom's residue_id fall between the
	 *         // Conformation's start_residue and end_residue values?
	 *         if ( atom.residue_id < conformation.start_residue )
	 *             return false;
	 *         if ( atom.residue_id > conformation.end_residue )
	 *             return false;
	 *         return true;
	 *     }
	 * };
	 * </PRE>
	 * <P>
	 */
	protected abstract boolean isLinked( StructureComponent subject,
		StructureComponent object );
	
	private void writeObject(java.io.ObjectOutputStream out) throws java.io.IOException {
		out.defaultWriteObject();               
	}
	private void readObject(java.io.ObjectInputStream in) throws java.io.IOException, ClassNotFoundException {
		in.defaultReadObject();
	} 

}