eu.wydler.pub.Talker.java Source code

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Here is the source code for eu.wydler.pub.Talker.java

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/*
 * Copyright (C) 2011 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package eu.wydler.pub;

import org.ros.message.geometry_msgs.Twist;
import org.ros.node.DefaultNodeFactory;
import org.ros.node.Node;
import org.ros.node.NodeConfiguration;
import org.ros.node.NodeMain;
import org.ros.node.topic.Publisher;

import com.google.common.base.Preconditions;

/**
 * @author michael.wydler@googlemail.com (Michael Wydler)
 */
public class Talker implements NodeMain {

    private Node node;
    private Publisher<org.ros.message.geometry_msgs.Twist> publisher;

    @Override
    public void main(NodeConfiguration configuration) {
        Preconditions.checkState(node == null);
        Preconditions.checkNotNull(configuration);
        try {
            node = new DefaultNodeFactory().newNode("talker", configuration);
            publisher = node.newPublisher("rpy", "geometry_msgs/Twist");
        } catch (Exception e) {
            if (node != null) {
                node.getLog().fatal(e);
            } else {
                e.printStackTrace();
            }
        }
    }

    @Override
    public void shutdown() {
        if (node != null) {
            node.shutdown();
            node = null;
        }
    }

    public void publish(Twist t) {
        try {
            publisher.publish(t);
        } catch (Exception e) {
            if (node != null) {
                node.getLog().fatal(e);
            } else {
                e.printStackTrace();
            }
        }
    }
}