es.deusto.weblab.client.lab.experiments.commands.RequestWebcamCommand.java Source code

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Here is the source code for es.deusto.weblab.client.lab.experiments.commands.RequestWebcamCommand.java

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/*
* Copyright (C) 2005 onwards University of Deusto
* All rights reserved.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution.
*
* This software consists of contributions made by many individuals, 
* listed below:
*
* Author: Luis Rodrguez <luis.rodriguez@opendeusto.es>
*
*/
package es.deusto.weblab.client.lab.experiments.commands;

import com.google.gwt.user.client.ui.Label;

import es.deusto.weblab.client.comm.exceptions.CommException;
import es.deusto.weblab.client.dto.experiments.Command;
import es.deusto.weblab.client.dto.experiments.ResponseCommand;
import es.deusto.weblab.client.lab.comm.callbacks.IResponseCommandCallback;
import es.deusto.weblab.client.lab.experiments.IBoardBaseController;
import es.deusto.weblab.client.ui.widgets.WlWebcam;

public class RequestWebcamCommand extends Command {

    public RequestWebcamCommand() {

    }

    @Override
    public String getCommandString() {
        return "WEBCAMURL";
    }

    /**
     * Retrieves the webcam URL from the response to the RequestWebcam command.
     * Note: The webcam request command follows the following format:
     * WEBCAMURL=http://www.whatever/webcam
     * 
     * @param requestResponse String containing the response to the command
     * @return Webcam URL. Null if the string can't be parsed.
     */
    public static String retrieveWebcamURL(String requestResponse) {
        final int eqsign = requestResponse.indexOf("=");
        if (eqsign == -1)
            return null;
        final String url = requestResponse.substring(eqsign + 1);
        return url;
    }

    /**
     * Helper method which creates a RequestWebcamCommands and sends it, 
     * updating by itself the webcam if it is successful or setting an error 
     * message if not.
     *
     * @param boardController Reference to the board controller to send
     * the command through.
     * @param webcam Reference to the wecam whose URL should be set.
     * @param messages Reference to the label which will display the 
     * error message, if any. If null, no error message will be set.
     */
    public static void createAndSend(IBoardBaseController boardController, final WlWebcam webcam,
            final Label messages) {

        final RequestWebcamCommand command = new RequestWebcamCommand();

        boardController.sendCommand(command, new IResponseCommandCallback() {

            @Override
            public void onSuccess(ResponseCommand responseCommand) {
                final String url = RequestWebcamCommand.retrieveWebcamURL(responseCommand.getCommandString());
                if (url != null && url.length() > 0) {
                    webcam.setUrl(url);
                }
            }

            @Override
            public void onFailure(CommException e) {
                if (messages != null)
                    messages.setText("Failed to obtain the webcam URL");
            }
        });

    }

}