/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2001 Intersect Software Corporation

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.ui;
import net.wotonomy.foundation.NSArray;

/**
* This master detail association synchronizes the contents
* and selection of the master group into the detail group.
*/
public class MirrorDetailAssociation extends MasterDetailAssociation{

    /** 
    * Standard constructor specifying the detail display group.
    * @param displayGroup the detail display group of this 
    * Master-Detail Association
    */
    public MirrorDetailAssociation(EODisplayGroup displayGroup){
        super(displayGroup);
    }

    /**
    * Called by subjectChanged() to requalify the controlled
    * display group with the indexed object and the bound key.
    * This implementation ignores both and sets the object array
    * of the detail group to the displayed objects of the master
    * and sets the selection to match.
    */
    protected void requalify()
    {
        EODisplayGroup detail = (EODisplayGroup) object();
        EODisplayGroup master =
            displayGroupForAspect( ParentAspect );

        if ( master != null )
        {
            NSArray masterObjects = master.displayedObjects();
            NSArray detailObjects = detail.displayedObjects();
            int size = masterObjects.size();
            boolean different = false;
            
            // see if lists contain the same object instances
            if ( size == detailObjects.size() )
            {
                for ( int i = 0; i < size; i++ )
                {
                    if ( masterObjects.objectAtIndex(i) 
                      != detailObjects.objectAtIndex(i) )
                    {
                        different = true;
                        break;
                    }
                }
            }
            else // different sizes
            {
                different = true;
            }
            
            // if different, sync contents and selection with master
            if ( different )
            {
                detail.setObjectArray( masterObjects );
                detail.setSelectionIndexes( master.selectionIndexes() );
            }
            else // if selection changed, sync selection with master
            if ( master.selectionChanged() )
            {
                detail.setSelectionIndexes( master.selectionIndexes() );
            }
        }
        else // no bound display group, clear
        {
            detail.setObjectArray( null );
        }
    }
}
/*
 * $Log$
 * Revision 1.1  2006/02/16 13:22:22  cgruber
 * Check in all sources in eclipse-friendly maven-enabled packages.
 *
 * Revision 1.2  2001/07/05 22:13:28  mpowers
 * Now only updating if master has actually changed.
 *
 * Revision 1.1  2001/05/29 19:57:47  mpowers
 * Added some neglected files.
 *
 *
 */