jdk/src/share/classes/javax/swing/tree/TreeModel.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/swing/tree/TreeModel.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,160 @@
+/*
+ * Copyright 1997-2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+package javax.swing.tree;
+
+import javax.swing.event.*;
+
+/**
+ * The model used by <code>JTree</code>.
+ * <p>
+ * <code>JTree</code> and its related classes make extensive use of
+ * <code>TreePath</code>s for indentifying nodes in the <code>TreeModel</code>.
+ * If a <code>TreeModel</code> returns the same object, as compared by
+ * <code>equals</code>, at two different indices under the same parent
+ * than the resulting <code>TreePath</code> objects will be considered equal
+ * as well. Some implementations may assume that if two
+ * <code>TreePath</code>s are equal, they identify the same node. If this
+ * condition is not met, painting problems and other oddities may result.
+ * In other words, if <code>getChild</code> for a given parent returns
+ * the same Object (as determined by <code>equals</code>) problems may
+ * result, and it is recommended you avoid doing this.
+ * <p>
+ * Similarly <code>JTree</code> and its related classes place
+ * <code>TreePath</code>s in <code>Map</code>s.  As such if
+ * a node is requested twice, the return values must be equal
+ * (using the <code>equals</code> method) and have the same
+ * <code>hashCode</code>.
+ * <p>
+ * For further information on tree models,
+ * including an example of a custom implementation,
+ * see <a
+ href="http://java.sun.com/docs/books/tutorial/uiswing/components/tree.html">How to Use Trees</a>
+ * in <em>The Java Tutorial.</em>
+ *
+ * @see TreePath
+ *
+ * @author Rob Davis
+ * @author Ray Ryan
+ */
+public interface TreeModel
+{
+
+    /**
+     * Returns the root of the tree.  Returns <code>null</code>
+     * only if the tree has no nodes.
+     *
+     * @return  the root of the tree
+     */
+    public Object getRoot();
+
+
+    /**
+     * Returns the child of <code>parent</code> at index <code>index</code>
+     * in the parent's
+     * child array.  <code>parent</code> must be a node previously obtained
+     * from this data source. This should not return <code>null</code>
+     * if <code>index</code>
+     * is a valid index for <code>parent</code> (that is <code>index >= 0 &&
+     * index < getChildCount(parent</code>)).
+     *
+     * @param   parent  a node in the tree, obtained from this data source
+     * @return  the child of <code>parent</code> at index <code>index</code>
+     */
+    public Object getChild(Object parent, int index);
+
+
+    /**
+     * Returns the number of children of <code>parent</code>.
+     * Returns 0 if the node
+     * is a leaf or if it has no children.  <code>parent</code> must be a node
+     * previously obtained from this data source.
+     *
+     * @param   parent  a node in the tree, obtained from this data source
+     * @return  the number of children of the node <code>parent</code>
+     */
+    public int getChildCount(Object parent);
+
+
+    /**
+     * Returns <code>true</code> if <code>node</code> is a leaf.
+     * It is possible for this method to return <code>false</code>
+     * even if <code>node</code> has no children.
+     * A directory in a filesystem, for example,
+     * may contain no files; the node representing
+     * the directory is not a leaf, but it also has no children.
+     *
+     * @param   node  a node in the tree, obtained from this data source
+     * @return  true if <code>node</code> is a leaf
+     */
+    public boolean isLeaf(Object node);
+
+    /**
+      * Messaged when the user has altered the value for the item identified
+      * by <code>path</code> to <code>newValue</code>.
+      * If <code>newValue</code> signifies a truly new value
+      * the model should post a <code>treeNodesChanged</code> event.
+      *
+      * @param path path to the node that the user has altered
+      * @param newValue the new value from the TreeCellEditor
+      */
+    public void valueForPathChanged(TreePath path, Object newValue);
+
+    /**
+     * Returns the index of child in parent.  If either <code>parent</code>
+     * or <code>child</code> is <code>null</code>, returns -1.
+     * If either <code>parent</code> or <code>child</code> don't
+     * belong to this tree model, returns -1.
+     *
+     * @param parent a node in the tree, obtained from this data source
+     * @param child the node we are interested in
+     * @return the index of the child in the parent, or -1 if either
+     *    <code>child</code> or <code>parent</code> are <code>null</code>
+     *    or don't belong to this tree model
+     */
+    public int getIndexOfChild(Object parent, Object child);
+
+//
+//  Change Events
+//
+
+    /**
+     * Adds a listener for the <code>TreeModelEvent</code>
+     * posted after the tree changes.
+     *
+     * @param   l       the listener to add
+     * @see     #removeTreeModelListener
+     */
+    void addTreeModelListener(TreeModelListener l);
+
+    /**
+     * Removes a listener previously added with
+     * <code>addTreeModelListener</code>.
+     *
+     * @see     #addTreeModelListener
+     * @param   l       the listener to remove
+     */
+    void removeTreeModelListener(TreeModelListener l);
+
+}