0N/A/*
2362N/A * Copyright (c) 2000, Oracle and/or its affiliates. All rights reserved.
0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
0N/A *
0N/A * This code is free software; you can redistribute it and/or modify it
0N/A * under the terms of the GNU General Public License version 2 only, as
2362N/A * published by the Free Software Foundation. Oracle designates this
0N/A * particular file as subject to the "Classpath" exception as provided
2362N/A * by Oracle in the LICENSE file that accompanied this code.
0N/A *
0N/A * This code is distributed in the hope that it will be useful, but WITHOUT
0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
0N/A * version 2 for more details (a copy is included in the LICENSE file that
0N/A * accompanied this code).
0N/A *
0N/A * You should have received a copy of the GNU General Public License version
0N/A * 2 along with this work; if not, write to the Free Software Foundation,
0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
0N/A *
2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
2362N/A * or visit www.oracle.com if you need additional information or have any
2362N/A * questions.
0N/A */
0N/A
0N/Apackage javax.imageio.spi;
0N/A
0N/Aimport java.io.Serializable;
0N/Aimport java.util.HashSet;
0N/Aimport java.util.Iterator;
0N/Aimport java.util.Set;
0N/A
0N/A/**
0N/A * A node in a directed graph. In addition to an arbitrary
0N/A * <code>Object</code> containing user data associated with the node,
0N/A * each node maintains a <code>Set</code>s of nodes which are pointed
0N/A * to by the current node (available from <code>getOutNodes</code>).
0N/A * The in-degree of the node (that is, number of nodes that point to
0N/A * the current node) may be queried.
0N/A *
0N/A */
0N/Aclass DigraphNode implements Cloneable, Serializable {
0N/A
0N/A /** The data associated with this node. */
0N/A protected Object data;
0N/A
0N/A /**
0N/A * A <code>Set</code> of neighboring nodes pointed to by this
0N/A * node.
0N/A */
0N/A protected Set outNodes = new HashSet();
0N/A
0N/A /** The in-degree of the node. */
0N/A protected int inDegree = 0;
0N/A
0N/A /**
0N/A * A <code>Set</code> of neighboring nodes that point to this
0N/A * node.
0N/A */
0N/A private Set inNodes = new HashSet();
0N/A
0N/A public DigraphNode(Object data) {
0N/A this.data = data;
0N/A }
0N/A
0N/A /** Returns the <code>Object</code> referenced by this node. */
0N/A public Object getData() {
0N/A return data;
0N/A }
0N/A
0N/A /**
0N/A * Returns an <code>Iterator</code> containing the nodes pointed
0N/A * to by this node.
0N/A */
public Iterator getOutNodes() {
return outNodes.iterator();
}
/**
* Adds a directed edge to the graph. The outNodes list of this
* node is updated and the in-degree of the other node is incremented.
*
* @param node a <code>DigraphNode</code>.
*
* @return <code>true</code> if the node was not previously the
* target of an edge.
*/
public boolean addEdge(DigraphNode node) {
if (outNodes.contains(node)) {
return false;
}
outNodes.add(node);
node.inNodes.add(this);
node.incrementInDegree();
return true;
}
/**
* Returns <code>true</code> if an edge exists between this node
* and the given node.
*
* @param node a <code>DigraphNode</code>.
*
* @return <code>true</code> if the node is the target of an edge.
*/
public boolean hasEdge(DigraphNode node) {
return outNodes.contains(node);
}
/**
* Removes a directed edge from the graph. The outNodes list of this
* node is updated and the in-degree of the other node is decremented.
*
* @return <code>true</code> if the node was previously the target
* of an edge.
*/
public boolean removeEdge(DigraphNode node) {
if (!outNodes.contains(node)) {
return false;
}
outNodes.remove(node);
node.inNodes.remove(this);
node.decrementInDegree();
return true;
}
/**
* Removes this node from the graph, updating neighboring nodes
* appropriately.
*/
public void dispose() {
Object[] inNodesArray = inNodes.toArray();
for(int i=0; i<inNodesArray.length; i++) {
DigraphNode node = (DigraphNode) inNodesArray[i];
node.removeEdge(this);
}
Object[] outNodesArray = outNodes.toArray();
for(int i=0; i<outNodesArray.length; i++) {
DigraphNode node = (DigraphNode) outNodesArray[i];
removeEdge(node);
}
}
/** Returns the in-degree of this node. */
public int getInDegree() {
return inDegree;
}
/** Increments the in-degree of this node. */
private void incrementInDegree() {
++inDegree;
}
/** Decrements the in-degree of this node. */
private void decrementInDegree() {
--inDegree;
}
}