// This Source Code is in the Public Domain per: http://unlicense.org
package org.litesoft.bo.change;

import org.litesoft.commonfoundation.typeutils.*;

import java.util.*;

public class OriginalValueChangeTrackerNull implements OriginalValueChangeTracker
{
    private static final long serialVersionUID = 1L;

    public static final OriginalValueChangeTracker INSTANCE = new OriginalValueChangeTrackerNull();

    public OriginalValueChangeTracker clear()
    {
        return this;
    }

    public boolean hasChanges()
    {
        return false;
    }

    public boolean isAttributeChanged( String pAttributeName )
    {
        return false;
    }

    public boolean isOriginalValueAvailableFor( String pAttributeName )
    {
        return false;
    }

    public Object getOriginalValueFor( String pAttributeName )
    {
        return null;
    }

    public ChangeEntry getOriginalValueChangeEntryFor( String pAttributeName )
    {
        return null;
    }

    public String[] getChangedAttributeNames()
    {
        return Strings.EMPTY_ARRAY;
    }

    public OriginalValueChangeTracker recordChange( String pAttributeName, ChangeEntry pNewChangeEntry, Object pOldValue, Object pNewValue )
    {
        return createRealTracker().recordChange( pAttributeName, pNewChangeEntry, pOldValue, pNewValue );
    }

    protected OriginalValueChangeTracker createRealTracker()
    {
        return new OriginalValueChangeTrackerImpl( new HashMap<String, ChangeEntry>() );
    }
}