kitaev@213: /*
kitaev@213:  * Copyright (c) 2011 TMate Software Ltd
kitaev@213:  *  
kitaev@213:  * This program is free software; you can redistribute it and/or modify
kitaev@213:  * it under the terms of the GNU General Public License as published by
kitaev@213:  * the Free Software Foundation; version 2 of the License.
kitaev@213:  *
kitaev@213:  * This program is distributed in the hope that it will be useful,
kitaev@213:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
kitaev@213:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
kitaev@213:  * GNU General Public License for more details.
kitaev@213:  *
kitaev@213:  * For information on how to redistribute this software under
kitaev@213:  * the terms of a license other than GNU General Public License
kitaev@213:  * contact TMate Software at support@hg4j.com
kitaev@213:  */
kitaev@213: package org.tmatesoft.hg.util;
kitaev@213: 
kitaev@213: /**
kitaev@213:  * Mix-in to report progress of a long-running operation
kitaev@213:  *  
kitaev@213:  * @author Artem Tikhomirov
kitaev@213:  * @author TMate Software Ltd.
kitaev@213:  */
kitaev@213: public interface ProgressSupport {
kitaev@213: 
kitaev@213: 	public void start(long totalUnits);
kitaev@213: 	public void worked(int units);
kitaev@213: 	public void done();
kitaev@213: 
kitaev@213: 	static class Factory {
kitaev@213: 
kitaev@213: 		/**
kitaev@213: 		 * @param target object that might be capable to report progress. Can be <code>null</code>
kitaev@213: 		 * @return support object extracted from target or an empty, no-op implementation
kitaev@213: 		 */
kitaev@213: 		public static ProgressSupport get(Object target) {
kitaev@213: 			if (target instanceof ProgressSupport) {
kitaev@213: 				return (ProgressSupport) target;
kitaev@213: 			}
kitaev@213: 			if (target instanceof Adaptable) {
kitaev@213: 				ProgressSupport ps = ((Adaptable) target).getAdapter(ProgressSupport.class);
kitaev@213: 				if (ps != null) {
kitaev@213: 					return ps;
kitaev@213: 				}
kitaev@213: 			}
kitaev@213: 			return new ProgressSupport() {
kitaev@213: 				public void start(long totalUnits) {
kitaev@213: 				}
kitaev@213: 				public void worked(int units) {
kitaev@213: 				}
kitaev@213: 				public void done() {
kitaev@213: 				}
kitaev@213: 			};
kitaev@213: 		}
kitaev@213: 	}
kitaev@213: }