001: /**
002: * Copyright (C) 2001 Yasna.com. All rights reserved.
003: *
004: * ===================================================================
005: * The Apache Software License, Version 1.1
006: *
007: * Redistribution and use in source and binary forms, with or without
008: * modification, are permitted provided that the following conditions
009: * are met:
010: *
011: * 1. Redistributions of source code must retain the above copyright
012: * notice, this list of conditions and the following disclaimer.
013: *
014: * 2. Redistributions in binary form must reproduce the above copyright
015: * notice, this list of conditions and the following disclaimer in
016: * the documentation and/or other materials provided with the
017: * distribution.
018: *
019: * 3. The end-user documentation included with the redistribution,
020: * if any, must include the following acknowledgment:
021: * "This product includes software developed by
022: * Yasna.com (http://www.yasna.com)."
023: * Alternately, this acknowledgment may appear in the software itself,
024: * if and wherever such third-party acknowledgments normally appear.
025: *
026: * 4. The names "Yazd" and "Yasna.com" must not be used to
027: * endorse or promote products derived from this software without
028: * prior written permission. For written permission, please
029: * contact yazd@yasna.com.
030: *
031: * 5. Products derived from this software may not be called "Yazd",
032: * nor may "Yazd" appear in their name, without prior written
033: * permission of Yasna.com.
034: *
035: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
036: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
037: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
038: * DISCLAIMED. IN NO EVENT SHALL YASNA.COM OR
039: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
040: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
041: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
042: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
043: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
044: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
045: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
046: * SUCH DAMAGE.
047: * ====================================================================
048: *
049: * This software consists of voluntary contributions made by many
050: * individuals on behalf of Yasna.com. For more information
051: * on Yasna.com, please see <http://www.yasna.com>.
052: */
053:
054: /**
055: * Copyright (C) 2000 CoolServlets.com. All rights reserved.
056: *
057: * ===================================================================
058: * The Apache Software License, Version 1.1
059: *
060: * Redistribution and use in source and binary forms, with or without
061: * modification, are permitted provided that the following conditions
062: * are met:
063: *
064: * 1. Redistributions of source code must retain the above copyright
065: * notice, this list of conditions and the following disclaimer.
066: *
067: * 2. Redistributions in binary form must reproduce the above copyright
068: * notice, this list of conditions and the following disclaimer in
069: * the documentation and/or other materials provided with the
070: * distribution.
071: *
072: * 3. The end-user documentation included with the redistribution,
073: * if any, must include the following acknowledgment:
074: * "This product includes software developed by
075: * CoolServlets.com (http://www.coolservlets.com)."
076: * Alternately, this acknowledgment may appear in the software itself,
077: * if and wherever such third-party acknowledgments normally appear.
078: *
079: * 4. The names "Jive" and "CoolServlets.com" must not be used to
080: * endorse or promote products derived from this software without
081: * prior written permission. For written permission, please
082: * contact webmaster@coolservlets.com.
083: *
084: * 5. Products derived from this software may not be called "Jive",
085: * nor may "Jive" appear in their name, without prior written
086: * permission of CoolServlets.com.
087: *
088: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
089: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
090: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
091: * DISCLAIMED. IN NO EVENT SHALL COOLSERVLETS.COM OR
092: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
093: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
094: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
095: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
096: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
097: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
098: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
099: * SUCH DAMAGE.
100: * ====================================================================
101: *
102: * This software consists of voluntary contributions made by many
103: * individuals on behalf of CoolServlets.com. For more information
104: * on CoolServlets.com, please see <http://www.coolservlets.com>.
105: */package com.Yasna.forum;
106:
107: /**
108: * Allows hierarchical navigation of a Thread. It closely follows the
109: * TreeModel interface in Swing in the hopes of being easier to use.
110: *
111: * @see ForumThread
112: */
113: public interface TreeWalker {
114:
115: /**
116: * Returns the root of the tree. Returns null only if the tree has no nodes.
117: *
118: * @returns the root of the tree
119: */
120: public ForumMessage getRoot();
121:
122: /**
123: * Returns the child of parent at index index in the parent's child array.
124: * This should not return null if index is a valid index for parent (that
125: * is index >= 0 && index < getChildCount(parent)).
126: *
127: * @param parent the parent message.
128: * @param index the index of the child.
129: * @returns the child of parent at index.
130: */
131: public ForumMessage getChild(ForumMessage parent, int index);
132:
133: /**
134: * Returns the number of children of parent. Returns 0 if the node is a
135: * leaf or if it has no children.
136: *
137: * @param parent a node in the tree, obtained from this data source.
138: * @returns the number of children of the node parent.
139: */
140: public int getChildCount(ForumMessage parent);
141:
142: /**
143: * Returns the total number of recursive children of a parent. Returns 0
144: * if there are no children. This method is not intended to aid in
145: * navigation of a Thread but is included as an added utility.
146: */
147: public int getRecursiveChildCount(ForumMessage parent);
148:
149: /**
150: * Returns the index of child in parent.
151: */
152: public int getIndexOfChild(ForumMessage parent, ForumMessage child);
153:
154: /**
155: * Returns true if node is a leaf. A node is a leaf when it has no children
156: * messages.
157: *
158: * @param node a node in the tree, obtained from this data source
159: * @returns true if node is a leaf
160: */
161: public boolean isLeaf(ForumMessage node);
162: }
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