/*******************************************************************************
 * Copyright (c) 2000, 2011 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.search.ui;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.OperationCanceledException;

/**
 * Represents a particular search query (in a Java example, a query might be
 * "find all occurrences of 'foo' in workspace"). When its run method is called, the query places
 * any results it finds in the <code>ISearchResult</code> that can be accessed via
 * getSearchResult(). Note that <code>getSearchResult</code> may be called at any time, even before
 * the <code>run()</code> method has been called. An empty search result should be returned in that
 * case.
 * <p>
 * Clients may implement this interface.
 * </p>
 *
 * @since 3.0
 */
public interface ISearchQuery {
	/**
	 * This is the method that actually does the work, i.e. finds the results of
	 * the search query.
	 *
	 * @param monitor the progress monitor to be used
	 *
	 * @return the status after completion of the search job.
	 * @throws OperationCanceledException Thrown when the search query has been canceled.
	 */
	IStatus run(IProgressMonitor monitor) throws OperationCanceledException;
	/**
	 * Returns a user readable label for this query. This will be used, for
	 * example to set the <code>Job</code> name if this query is executed in
	 * the background. Note that progress notification (for example, the number
	 * of matches found) should be done via the progress monitor passed into the
	 * <code>run(IProgressMonitor)</code> method
	 *
	 * @return the user readable label of this query
	 */
	String getLabel();
	/**
	 * Returns whether the query can be run more than once. Some queries may
	 * depend on transient information and return <code>false</code>.
	 *
	 * @return whether this query can be run more than once
	 */
	boolean canRerun();
	/**
	 * Returns whether this query can be run in the background. Note that
	 * queries must do proper locking when they are run in the background (e.g.
	 * get the appropriate workspace locks).
	 *
	 * @return whether this query can be run in the background
	 */
	boolean canRunInBackground();
	/**
	 * Returns the search result associated with this query. This method can be
	 * called before run is called.
	 *
	 * @return this query's search result
	 */
	ISearchResult getSearchResult();
}