/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.ignite.internal.util.lang;
import java.io.IOException;
import java.util.List;
/**
* Abstract tree structure printer.
*/
public abstract class GridTreePrinter<T> {
/**
* @param rootNode Root tree node.
* @param a Output.
*/
public void print(T rootNode, Appendable a) throws IOException {
printTree(rootNode, "", true, a);
}
/**
* @param rootNode Root tree node.
* @return String representation of the tree.
*/
public String print(T rootNode) {
StringBuilder b = new StringBuilder();
try {
print(rootNode, b);
}
catch (IOException e) {
throw new IllegalStateException(e);
}
return b.toString();
}
/**
* @param treeNode Tree node.
* @param prefix Prefix.
* @param tail Tail child.
* @param a Output.
* @throws IOException
*/
private void printTree(T treeNode, String prefix, boolean tail, Appendable a) throws IOException {
List<T> children = getChildren(treeNode);
int cnt = children == null ? 0 : children.size();
a.append(prefix).append(tail ? "└── " : "├── ").append(formatTreeNode(treeNode)).append('\n');
for (int i = 0; i < cnt; i++)
printTree(children.get(i), prefix + (tail ? " " : "│ "), i == cnt - 1, a);
}
/**
* @param treeNode Tree node.
* @return List of children.
*/
protected abstract List<T> getChildren(T treeNode);
/**
* @param treeNode Tree node.
* @return String representation.
*/
protected abstract String formatTreeNode(T treeNode);
}