/* interface TreeModel
*
* Copyright (C) 2003 R M Pitman
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package charvax.swing.tree;
import charvax.swing.event.TreeModelListener;
/**
* This interface defines a suitable data model for a JTree.
*/
public interface TreeModel
{
/** Returns the root of the tree.
* Returns null only if the tree has no nodes.
*/
public Object getRoot();
/** Returns the child of parent at index index in the parent's child
* array. parent must be a node previously obtained from this data
* source. This should not return null if index is a valid index for
* parent (that is index >= 0 && index < getChildCount(parent)).
*/
public Object getChild(Object parent, int index);
/** Returns the number of children of parent. Returns 0 if the node
* is a leaf or if it has no children. parent must be a node previously
* obtained from this data source.
*/
public int getChildCount(Object parent);
/** Returns true if node is a leaf. It is possible for this method to
* return false even if node 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.
*/
public boolean isLeaf(Object node);
/** Called when the user has altered the value for the item
* identified by path to newValue. If newValue signifies a truly new
* value the model should post a treeNodesChanged event.
*/
public void valueForPathChanged(TreePath path, Object newValue);
/** Adds a listener for the TreeModelEvent posted after the tree changes.
*/
public void addTreeModelListener(TreeModelListener l);
/** Removes a listener previously added with addTreeModelListener.
*/
public void removeTreeModelListener(TreeModelListener l);
}