tikhomirov@520: /*
tikhomirov@520:  * Copyright (c) 2012 TMate Software Ltd
tikhomirov@520:  *  
tikhomirov@520:  * This program is free software; you can redistribute it and/or modify
tikhomirov@520:  * it under the terms of the GNU General Public License as published by
tikhomirov@520:  * the Free Software Foundation; version 2 of the License.
tikhomirov@520:  *
tikhomirov@520:  * This program is distributed in the hope that it will be useful,
tikhomirov@520:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
tikhomirov@520:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
tikhomirov@520:  * GNU General Public License for more details.
tikhomirov@520:  *
tikhomirov@520:  * For information on how to redistribute this software under
tikhomirov@520:  * the terms of a license other than GNU General Public License
tikhomirov@520:  * contact TMate Software at support@hg4j.com
tikhomirov@520:  */
tikhomirov@520: package org.tmatesoft.hg.internal;
tikhomirov@520: 
tikhomirov@520: import org.tmatesoft.hg.util.CancelSupport;
tikhomirov@520: import org.tmatesoft.hg.util.CancelledException;
tikhomirov@520: import org.tmatesoft.hg.util.ProgressSupport;
tikhomirov@520: 
tikhomirov@520: /**
tikhomirov@520:  * Bridge low-level life-cycle ({@link Lifecycle}) API with high-level one ({@link ProgressSupport} and {@link CancelSupport}).
tikhomirov@520:  * 
tikhomirov@520:  * @author Artem Tikhomirov
tikhomirov@520:  * @author TMate Software Ltd.
tikhomirov@520:  */
tikhomirov@520: public class LifecycleBridge implements Lifecycle {
tikhomirov@520: 	private final ProgressSupport progressHelper;
tikhomirov@520: 	private final CancelSupport cancelSupport;
tikhomirov@520: 	// may be null unless #start() is invoked
tikhomirov@520: 	private Callback receiver;
tikhomirov@520: 	private CancelledException cancellation;
tikhomirov@520: 
tikhomirov@520: 	
tikhomirov@520: 	public LifecycleBridge(ProgressSupport progress, CancelSupport cancel) {
tikhomirov@520: 		progressHelper = progress;
tikhomirov@520: 		cancelSupport = cancel;
tikhomirov@520: 	}
tikhomirov@520: 
tikhomirov@520: 	public void start(int count, Callback callback, Object token) {
tikhomirov@520: 		receiver = callback;
tikhomirov@520: 		if (progressHelper != null) {
tikhomirov@520: 			progressHelper.start(count);
tikhomirov@520: 		}
tikhomirov@520: 	}
tikhomirov@520: 
tikhomirov@520: 	public void finish(Object token) {
tikhomirov@520: 		if (progressHelper != null) {
tikhomirov@520: 			progressHelper.done();
tikhomirov@520: 		}
tikhomirov@520: 		receiver = null;
tikhomirov@520: 	}
tikhomirov@520: 
tikhomirov@520: 	// XXX SHALL work without start/finish sequence because
tikhomirov@520: 	// HgLogCommand invokes ChangesetTransformer#next directly (i.e. not from
tikhomirov@520: 	// inside a library's #range() or similar) to process changesets in unnatural order.
tikhomirov@520: 	public void nextStep() {
tikhomirov@520: 		if (progressHelper != null) {
tikhomirov@520: 			progressHelper.worked(1);
tikhomirov@520: 		}
tikhomirov@520: 		if (cancelSupport == null) {
tikhomirov@520: 			return;
tikhomirov@520: 		}
tikhomirov@520: 		try { 
tikhomirov@520: 			cancelSupport.checkCancelled();
tikhomirov@520: 		} catch (CancelledException ex) {
tikhomirov@520: 			if (receiver != null) {
tikhomirov@520: 				receiver.stop();
tikhomirov@520: 			}
tikhomirov@520: 			cancellation = ex;
tikhomirov@520: 		}
tikhomirov@520: 	}
tikhomirov@520: 
tikhomirov@520: 	public void stop() {
tikhomirov@520: 		if (receiver != null) {
tikhomirov@520: 			receiver.stop();
tikhomirov@520: 		}
tikhomirov@520: 	}
tikhomirov@520: 	
tikhomirov@520: 	/**
tikhomirov@520: 	 * @return <code>true</code> iff {@link CancelledException} was thrown and catched. Forced stop doesn't count
tikhomirov@520: 	 */
tikhomirov@520: 	public boolean isCancelled() {
tikhomirov@520: 		return cancellation != null;
tikhomirov@520: 	}
tikhomirov@520: 	
tikhomirov@520: 	public CancelledException getCancelOrigin() {
tikhomirov@520: 		return cancellation;
tikhomirov@520: 	}
tikhomirov@520: }