org.ros.internal.node.topic.TopicDeclaration.java Source code

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Here is the source code for org.ros.internal.node.topic.TopicDeclaration.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 org.ros.internal.node.topic;

import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;

import org.ros.internal.message.topic.TopicDescription;
import org.ros.internal.transport.ConnectionHeader;
import org.ros.internal.transport.ConnectionHeaderFields;
import org.ros.namespace.GraphName;

import java.util.List;
import java.util.Map;

/**
 * A topic in a ROS graph.
 *
 * @author damonkohler@google.com (Damon Kohler)
 */
public class TopicDeclaration {

    private final TopicIdentifier topicIdentifier;
    private final TopicDescription topicDescription;

    /**
     * @param header
     *          a {@link Map} of header fields
     * @return a new {@link TopicDeclaration} from the given header
     */
    public static TopicDeclaration newFromHeader(Map<String, String> header) {
        Preconditions.checkArgument(header.containsKey(ConnectionHeaderFields.TOPIC));
        GraphName name = GraphName.of(header.get(ConnectionHeaderFields.TOPIC));
        String type = header.get(ConnectionHeaderFields.TYPE);
        String definition = header.get(ConnectionHeaderFields.MESSAGE_DEFINITION);
        String md5Checksum = header.get(ConnectionHeaderFields.MD5_CHECKSUM);
        TopicDescription topicDescription = new TopicDescription(type, definition, md5Checksum);
        return new TopicDeclaration(new TopicIdentifier(name), topicDescription);
    }

    public static TopicDeclaration newFromTopicName(GraphName topicName, TopicDescription topicDescription) {
        return new TopicDeclaration(new TopicIdentifier(topicName), topicDescription);
    }

    public TopicDeclaration(TopicIdentifier topicIdentifier, TopicDescription topicDescription) {
        Preconditions.checkNotNull(topicIdentifier);
        Preconditions.checkNotNull(topicDescription);
        this.topicIdentifier = topicIdentifier;
        this.topicDescription = topicDescription;
    }

    public TopicIdentifier getIdentifier() {
        return topicIdentifier;
    }

    public GraphName getName() {
        return topicIdentifier.getName();
    }

    public String getMessageType() {
        return topicDescription.getType();
    }

    public ConnectionHeader toConnectionHeader() {
        ConnectionHeader connectionHeader = new ConnectionHeader();
        connectionHeader.merge(topicIdentifier.toConnectionHeader());
        connectionHeader.addField(ConnectionHeaderFields.TYPE, topicDescription.getType());
        connectionHeader.addField(ConnectionHeaderFields.MESSAGE_DEFINITION, topicDescription.getDefinition());
        connectionHeader.addField(ConnectionHeaderFields.MD5_CHECKSUM, topicDescription.getMd5Checksum());
        return connectionHeader;
    }

    public List<String> toList() {
        return Lists.newArrayList(getName().toString(), getMessageType());
    }

    @Override
    public String toString() {
        return "Topic<" + topicIdentifier + ", " + topicDescription.toString() + ">";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((topicDescription == null) ? 0 : topicDescription.hashCode());
        result = prime * result + ((topicIdentifier == null) ? 0 : topicIdentifier.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        TopicDeclaration other = (TopicDeclaration) obj;
        if (topicDescription == null) {
            if (other.topicDescription != null)
                return false;
        } else if (!topicDescription.equals(other.topicDescription))
            return false;
        if (topicIdentifier == null) {
            if (other.topicIdentifier != null)
                return false;
        } else if (!topicIdentifier.equals(other.topicIdentifier))
            return false;
        return true;
    }
}