J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2005 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | package javax.swing.tree; |
| 26 | |
| 27 | import javax.swing.event.*; |
| 28 | |
| 29 | /** |
| 30 | * The model used by <code>JTree</code>. |
| 31 | * <p> |
| 32 | * <code>JTree</code> and its related classes make extensive use of |
| 33 | * <code>TreePath</code>s for indentifying nodes in the <code>TreeModel</code>. |
| 34 | * If a <code>TreeModel</code> returns the same object, as compared by |
| 35 | * <code>equals</code>, at two different indices under the same parent |
| 36 | * than the resulting <code>TreePath</code> objects will be considered equal |
| 37 | * as well. Some implementations may assume that if two |
| 38 | * <code>TreePath</code>s are equal, they identify the same node. If this |
| 39 | * condition is not met, painting problems and other oddities may result. |
| 40 | * In other words, if <code>getChild</code> for a given parent returns |
| 41 | * the same Object (as determined by <code>equals</code>) problems may |
| 42 | * result, and it is recommended you avoid doing this. |
| 43 | * <p> |
| 44 | * Similarly <code>JTree</code> and its related classes place |
| 45 | * <code>TreePath</code>s in <code>Map</code>s. As such if |
| 46 | * a node is requested twice, the return values must be equal |
| 47 | * (using the <code>equals</code> method) and have the same |
| 48 | * <code>hashCode</code>. |
| 49 | * <p> |
| 50 | * For further information on tree models, |
| 51 | * including an example of a custom implementation, |
| 52 | * see <a |
| 53 | href="http://java.sun.com/docs/books/tutorial/uiswing/components/tree.html">How to Use Trees</a> |
| 54 | * in <em>The Java Tutorial.</em> |
| 55 | * |
| 56 | * @see TreePath |
| 57 | * |
| 58 | * @author Rob Davis |
| 59 | * @author Ray Ryan |
| 60 | */ |
| 61 | public interface TreeModel |
| 62 | { |
| 63 | |
| 64 | /** |
| 65 | * Returns the root of the tree. Returns <code>null</code> |
| 66 | * only if the tree has no nodes. |
| 67 | * |
| 68 | * @return the root of the tree |
| 69 | */ |
| 70 | public Object getRoot(); |
| 71 | |
| 72 | |
| 73 | /** |
| 74 | * Returns the child of <code>parent</code> at index <code>index</code> |
| 75 | * in the parent's |
| 76 | * child array. <code>parent</code> must be a node previously obtained |
| 77 | * from this data source. This should not return <code>null</code> |
| 78 | * if <code>index</code> |
| 79 | * is a valid index for <code>parent</code> (that is <code>index >= 0 && |
| 80 | * index < getChildCount(parent</code>)). |
| 81 | * |
| 82 | * @param parent a node in the tree, obtained from this data source |
| 83 | * @return the child of <code>parent</code> at index <code>index</code> |
| 84 | */ |
| 85 | public Object getChild(Object parent, int index); |
| 86 | |
| 87 | |
| 88 | /** |
| 89 | * Returns the number of children of <code>parent</code>. |
| 90 | * Returns 0 if the node |
| 91 | * is a leaf or if it has no children. <code>parent</code> must be a node |
| 92 | * previously obtained from this data source. |
| 93 | * |
| 94 | * @param parent a node in the tree, obtained from this data source |
| 95 | * @return the number of children of the node <code>parent</code> |
| 96 | */ |
| 97 | public int getChildCount(Object parent); |
| 98 | |
| 99 | |
| 100 | /** |
| 101 | * Returns <code>true</code> if <code>node</code> is a leaf. |
| 102 | * It is possible for this method to return <code>false</code> |
| 103 | * even if <code>node</code> has no children. |
| 104 | * A directory in a filesystem, for example, |
| 105 | * may contain no files; the node representing |
| 106 | * the directory is not a leaf, but it also has no children. |
| 107 | * |
| 108 | * @param node a node in the tree, obtained from this data source |
| 109 | * @return true if <code>node</code> is a leaf |
| 110 | */ |
| 111 | public boolean isLeaf(Object node); |
| 112 | |
| 113 | /** |
| 114 | * Messaged when the user has altered the value for the item identified |
| 115 | * by <code>path</code> to <code>newValue</code>. |
| 116 | * If <code>newValue</code> signifies a truly new value |
| 117 | * the model should post a <code>treeNodesChanged</code> event. |
| 118 | * |
| 119 | * @param path path to the node that the user has altered |
| 120 | * @param newValue the new value from the TreeCellEditor |
| 121 | */ |
| 122 | public void valueForPathChanged(TreePath path, Object newValue); |
| 123 | |
| 124 | /** |
| 125 | * Returns the index of child in parent. If either <code>parent</code> |
| 126 | * or <code>child</code> is <code>null</code>, returns -1. |
| 127 | * If either <code>parent</code> or <code>child</code> don't |
| 128 | * belong to this tree model, returns -1. |
| 129 | * |
| 130 | * @param parent a node in the tree, obtained from this data source |
| 131 | * @param child the node we are interested in |
| 132 | * @return the index of the child in the parent, or -1 if either |
| 133 | * <code>child</code> or <code>parent</code> are <code>null</code> |
| 134 | * or don't belong to this tree model |
| 135 | */ |
| 136 | public int getIndexOfChild(Object parent, Object child); |
| 137 | |
| 138 | // |
| 139 | // Change Events |
| 140 | // |
| 141 | |
| 142 | /** |
| 143 | * Adds a listener for the <code>TreeModelEvent</code> |
| 144 | * posted after the tree changes. |
| 145 | * |
| 146 | * @param l the listener to add |
| 147 | * @see #removeTreeModelListener |
| 148 | */ |
| 149 | void addTreeModelListener(TreeModelListener l); |
| 150 | |
| 151 | /** |
| 152 | * Removes a listener previously added with |
| 153 | * <code>addTreeModelListener</code>. |
| 154 | * |
| 155 | * @see #addTreeModelListener |
| 156 | * @param l the listener to remove |
| 157 | */ |
| 158 | void removeTreeModelListener(TreeModelListener l); |
| 159 | |
| 160 | } |