bundles/org.eclipse.equinox.p2.ui/src/org/eclipse/equinox/internal/provisional/p2/ui/RepositoryLocationQuery.java

/*******************************************************************************
 * Copyright (c) 2009 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 ******************************************************************************/

package org.eclipse.equinox.internal.provisional.p2.ui;

import java.net.URI;
import java.util.Iterator;
import org.eclipse.equinox.internal.p2.core.helpers.QueryHelpers;
import org.eclipse.equinox.internal.provisional.p2.query.Collector;
import org.eclipse.equinox.internal.provisional.p2.query.Query;
import org.eclipse.equinox.internal.provisional.p2.repository.IRepository;

/**
 * RepositoryLocationQuery is a query that gathers repository
 * locations rather than repositories.  It is used when composing
 * queries against a QueryableRepositoryManager to indicate that the
 * repository need not be loaded to run the query.  
 * 
 * @since 3.5
 */
public class RepositoryLocationQuery implements Query {

	/**
	 * Gets the ID for this Query. 
	 */
	public String getId() {
		return QueryHelpers.getId(this);
	}

	/**
	 * Gets a particular property of the query.
	 * @param property The property to retrieve 
	 */
	public Object getProperty(String property) {
		return QueryHelpers.getProperty(this, property);
	}

	/* (non-Javadoc)
	 * @see org.eclipse.equinox.internal.provisional.p2.query.Query#perform(java.util.Iterator, org.eclipse.equinox.internal.provisional.p2.query.Collector)
	 */
	public Collector perform(Iterator iterator, Collector result) {
		while (iterator.hasNext()) {
			Object candidate = iterator.next();
			URI location = getLocation(candidate);
			if (location != null)
				if (!result.accept(location))
					break;
		}
		return result;
	}

	private URI getLocation(Object o) {
		if (o instanceof URI)
			return (URI) o;
		if (o instanceof IRepository)
			return ((IRepository) o).getLocation();
		return null;
	}
}