org.abego.treelayout.util.DefaultTreeForTreeLayout Maven / Gradle / Ivy
Show all versions of virtdata-lib-realer Show documentation
/*
* [The "BSD license"]
* Copyright (c) 2011, abego Software GmbH, Germany (http://www.abego.org)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of the abego Software GmbH nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package org.abego.treelayout.util;
import static org.abego.treelayout.internal.util.Contract.checkArg;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Provides a generic implementation for the {@link org.abego.treelayout.TreeForTreeLayout}
* interface, applicable to any type of tree node.
*
* It allows you to create a tree "from scratch", without creating any new
* class.
*
* To create a tree you must provide the root of the tree (see
* {@link #DefaultTreeForTreeLayout(Object)}. Then you can incrementally
* construct the tree by adding children to the root or other nodes of the tree
* (see {@link #addChild(Object, Object)} and
* {@link #addChildren(Object, Object...)}).
*
* @author Udo Borkowski ([email protected])
*
* @param Type of elements used as nodes in the tree
*/
public class DefaultTreeForTreeLayout extends
AbstractTreeForTreeLayout {
private List emptyList;
private List getEmptyList() {
if (emptyList == null) {
emptyList = new ArrayList();
}
return emptyList;
}
private Map> childrenMap = new HashMap>();
private Map parents = new HashMap();
/**
* Creates a new instance with a given node as the root
*
* @param root
* the node to be used as the root.
*/
public DefaultTreeForTreeLayout(TreeNode root) {
super(root);
}
@Override
public TreeNode getParent(TreeNode node) {
return parents.get(node);
}
@Override
public List getChildrenList(TreeNode node) {
List result = childrenMap.get(node);
return result == null ? getEmptyList() : result;
}
/**
*
* @param node
* @return true iff the node is in the tree
*/
public boolean hasNode(TreeNode node) {
return node == getRoot() || parents.containsKey(node);
}
/**
* @param parentNode
* [hasNode(parentNode)]
* @param node
* [!hasNode(node)]
*/
public void addChild(TreeNode parentNode, TreeNode node) {
checkArg(hasNode(parentNode), "parentNode is not in the tree");
checkArg(!hasNode(node), "node is already in the tree");
List list = childrenMap.get(parentNode);
if (list == null) {
list = new ArrayList();
childrenMap.put(parentNode, list);
}
list.add(node);
parents.put(node, parentNode);
}
public void addChildren(TreeNode parentNode, TreeNode... nodes) {
for (TreeNode node : nodes) {
addChild(parentNode, node);
}
}
}