view java/src/uk/ac/qmul/eecs/ccmi/network/DiagramDownloader.java @ 1:e3935c01cde2 tip

moved license of PdPersistenceManager to the beginning of the file

/*  
 CCmI Editor - A Collaborative Cross-Modal Diagram Editing Tool
  
 Copyright (C) 2011  Queen Mary University of London (http://ccmi.eecs.qmul.ac.uk/)

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/  

package uk.ac.qmul.eecs.ccmi.network;


import java.net.InetSocketAddress;
import java.nio.channels.SocketChannel;

import uk.ac.qmul.eecs.ccmi.gui.DiagramEventSource;
import uk.ac.qmul.eecs.ccmi.gui.SpeechOptionPane;
import uk.ac.qmul.eecs.ccmi.utils.PreferencesService;

/**
 * A {@code SwingWorker} that takes on the communication with the server in the very first phase of the 
 * connection for a new diagram. It handles the download of the list of diagrams available for sharing on the server
 * and, once the user has chosen one, it downloads the diagram into the local editor. 
 * Since this tasks can take a long time due to network delay and the interaction has not yet started
 * a {@code SwingWorker} is used so that the user interface won't get stuck in the process, the user
 * being able to cancel the job and to go back to the diagram editor. 
 *
 */
public class DiagramDownloader extends SpeechOptionPane.ProgressDialogWorker<String,Void> {

	public DiagramDownloader(SocketChannel channel, String target, int task){
		this.channel = channel;
		this.task = task;
		if(task == CONNECT_AND_DOWNLOAD_LIST_TASK)
			this.address = target;
		else
			this.diagramName = target;
	}
	
	@Override
	protected String doInBackground() throws Exception {
		if(task == CONNECT_AND_DOWNLOAD_LIST_TASK){
			int port = Integer.parseInt(PreferencesService.getInstance().get("server.remote_port", Server.DEFAULT_REMOTE_PORT));
			channel.connect(new InetSocketAddress(address,port));
		}
		
		Protocol protocol = ProtocolFactory.newInstance();
		switch(task){
			case CONNECT_AND_DOWNLOAD_LIST_TASK : 
				protocol.send(channel, new Command(Command.Name.LIST,"",DiagramEventSource.NONE));
				break;
			case DOWNLOAD_DIAGRAM_TASK :	
				protocol.send(channel, new Command(Command.Name.GET ,diagramName,DiagramEventSource.NONE));
		}
		Reply reply = protocol.receiveReply(channel);
		switch(reply.getName()){
		case ERROR_R : 
			throw new DiagramShareException(reply.getMessage());
		case LIST_R :
			String result = new String(reply.getMessage());
			if("".equals(result))
				return null;
			return result;
		case GET_R : 
			return reply.getMessage();
		default : throw new RuntimeException();
		}
	}
	
	public static final int CONNECT_AND_DOWNLOAD_LIST_TASK = 0;
	public static final int DOWNLOAD_DIAGRAM_TASK = 1;

	private SocketChannel channel;
	private String diagramName;
	private String address;
	private int task;
}