com.github.fritaly.graphml4j.datastructure.Node.java Source code

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Here is the source code for com.github.fritaly.graphml4j.datastructure.Node.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 com.github.fritaly.graphml4j.datastructure;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;

import org.apache.commons.lang.Validate;
import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;

import com.github.fritaly.graphml4j.Renderer;

public final class Node implements Comparable<Node> {

    private final String id;

    private final Set<Node> children = new TreeSet<Node>();

    private final Graph graph;

    private Node parent;

    private final Object data;

    // TODO Create a class NodeRenderer to generate the label of a node

    Node(Graph graph, String id, Object data) {
        // the node data can be null
        Validate.notNull(graph, "The given graph is null");
        Validate.notNull(id, "The given node id is null");

        this.graph = graph;
        this.id = id;
        this.data = data;
    }

    public String getLabel() {
        return hasData() ? getData().toString() : getId();
    }

    String getLabel(Renderer renderer) {
        // the renderer can be null
        return (renderer != null) ? renderer.getNodeLabel(this) : getLabel();
    }

    public Object getData() {
        return data;
    }

    public boolean hasData() {
        return (data != null);
    }

    Graph getGraph() {
        return graph;
    }

    @Override
    public int compareTo(Node node) {
        return this.id.compareTo(node.id);
    }

    public Node getParent() {
        return this.parent;
    }

    public boolean hasParent() {
        return (this.parent != null);
    }

    public void setParent(Node node) {
        // the parent can be null

        if (this.parent != null) {
            // if there's a current parent node, unlink the 2 nodes
            this.parent.children.remove(this);
        } else {
            // the parent is the root graph
            this.graph.childNodes.remove(this.getId());
        }

        this.parent = node;

        if (node != null) {
            // link the 2 nodes
            node.children.add(this);
        } else {
            // the parent is the root graph
            this.graph.childNodes.put(this.getId(), this);
        }
    }

    public void detach() {
        // detach the node from its parent (if any)
        // this method won't remove the node from the graph, it'll move
        // the node to the root of the graph
        setParent(null);
    }

    public String getId() {
        return id;
    }

    public boolean isGroup() {
        return !this.children.isEmpty();
    }

    public List<Node> getChildren() {
        return new ArrayList<Node>(this.children);
    }

    public void addChild(Node node) {
        // TODO check that the node belongs to the same graph
        Validate.notNull(node, "The given node is null");
        Validate.isTrue(this.graph == node.graph, "The given node doesn't belong to the same graph");
        Validate.isTrue(this != node, "A node can't be its own child or parent");

        this.children.add(node);
    }

    @Override
    public String toString() {
        return new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE).append("id", id).append("data", data)
                .toString();
    }
}