echopointng.tree.TreeModel Maven / Gradle / Ivy
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package echopointng.tree;
/*
* This file is part of the Echo Point Project. This project is a collection
* of Components that have extended the Echo Web Application Framework.
*
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*/
/*
* The design paradigm and class name used within have been taken directly from
* the java.swing package has been retro-fitted to work with the NextApp Echo web framework.
*
* This file was made part of the EchoPoint project on the 25/07/2002.
*
*/
/**
* The TreeModel interface defines a suitable data model for a Tree.
*
* There is an implied behavioural contract between a Tree and its TreeModel. The
* Tree gaurantees not to call any of the getChildXXX() methods until they
* are absolutely needed (for example a parent node is expanded).
*
* This is to allow children to be lazily created "as needed". Ths is useful for
* very large TreeModels or ones where child node creation is an expensive operation
*
* Note that the isLeaf() may be called at any time and if
* it returns true, then the node cannot contain any child nodes. However the inverse if not
* necessarily true. A model may return that a node is NOT a leaf but it may still
* have zero child nodes.
*
*/
public interface TreeModel {
/**
* Adds a listener for the TreeModelEvent posted after the tree changes.
*
* @param l the listener to add
*/
public void addTreeModelListener(TreeModelListener l);
/**
* 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)).
*
* @param parent a node in the tree, obtained from this data source
* @return the child of parent at index index
*/
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.
*
* @param parent a node in the tree, obtained from this data source
* @return the number of children of the node parent
*/
public int getChildCount(Object parent);
/**
* Returns the index of child in parent.
*/
public int getIndexOfChild(Object parent, Object child);
/**
* Returns the root of the tree. Returns null only if the tree has
* no nodes.
*
* @return the root of the tree
*/
public Object getRoot();
/**
* 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.
*
* @param node a node in the tree, obtained from this data source
* @return true if node is a leaf
*/
public boolean isLeaf(Object node);
/**
* Removes a listener previously added with addTreeModelListener().
*
*/
public void removeTreeModelListener(TreeModelListener l);
/**
* Messaged 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.
*
* @param path path to the node that the user has altered.
* @param newValue the new value from the Tree.
*/
public void valueForPathChanged(TreePath path, Object newValue);
/**
* Returns an identifier for a node. The identifier should be assigned
* to the Node when added to the model and thereafter it should not change.
*
* @return String - a unique identifier for a specific node
*/
public String getNodeId(Object node);
/**
* @return a node Object based on its unique identifier (obtained using getNodeId)
*/
public Object getNodeById(String id);
}