/*******************************************************************************
 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
 * in Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.browsing.ui.graph.tester;

import java.util.Collection;

import org.simantics.browsing.ui.NodeContext;
import org.simantics.browsing.ui.NodeQueryManager;
import org.simantics.browsing.ui.Tester;
import org.simantics.browsing.ui.graph.impl.CommonKeys;
import org.simantics.db.ReadGraph;
import org.simantics.db.RequestProcessor;
import org.simantics.db.Resource;
import org.simantics.db.common.request.ReadRequest;
import org.simantics.db.exception.DatabaseException;
import org.simantics.utils.Container;

/**
 * @author Tuukka Lehtonen
 */
public class HasRelatedObjectsTester implements Tester {

    private Resource relation;

    public HasRelatedObjectsTester(Resource relation) {
        this.relation = relation;
    }

    public HasRelatedObjectsTester(RequestProcessor processor, final String relationUri) throws DatabaseException {
        processor.syncRequest(new ReadRequest() {
            @Override
            public void run(ReadGraph graph) throws DatabaseException {
                relation = graph.getResource(relationUri);
            }
        });
    }

    @Override
    public boolean test(NodeQueryManager manager, NodeContext context) {
        Container<Collection<Resource>> objects = manager.query(context, new CommonKeys.RelatedObjectsKey(relation));
        return !objects.get().isEmpty();
    }

}