com.google.gerrit.server.util.TreeFormatter Maven / Gradle / Ivy
// Copyright (C) 2011 The Android Open Source Project
//
// Licensed 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 com.google.gerrit.server.util;
import java.io.PrintWriter;
import java.util.NavigableSet;
public class TreeFormatter {
public interface TreeNode {
String getDisplayName();
boolean isVisible();
NavigableSet getChildren();
}
public static final String NOT_VISIBLE_NODE = "(x)";
private static final String NODE_PREFIX = "|-- ";
private static final String LAST_NODE_PREFIX = "`-- ";
private static final String DEFAULT_TAB_SEPARATOR = "|";
private final PrintWriter stdout;
private String currentTabSeparator = " ";
public TreeFormatter(PrintWriter stdout) {
this.stdout = stdout;
}
public void printTree(NavigableSet rootNodes) {
if (rootNodes.isEmpty()) {
return;
}
if (rootNodes.size() == 1) {
printTree(rootNodes.first());
} else {
currentTabSeparator = DEFAULT_TAB_SEPARATOR;
int i = 0;
final int size = rootNodes.size();
for (TreeNode rootNode : rootNodes) {
final boolean isLastRoot = ++i == size;
if (isLastRoot) {
currentTabSeparator = " ";
}
printTree(rootNode);
}
}
}
public void printTree(TreeNode rootNode) {
printTree(rootNode, 0, true);
}
private void printTree(TreeNode node, int level, boolean isLast) {
printNode(node, level, isLast);
final NavigableSet childNodes = node.getChildren();
int i = 0;
final int size = childNodes.size();
for (TreeNode childNode : childNodes) {
final boolean isLastChild = ++i == size;
printTree(childNode, level + 1, isLastChild);
}
}
private void printIndention(int level) {
if (level > 0) {
stdout.print(String.format("%-" + 4 * level + "s", currentTabSeparator));
}
}
private void printNode(TreeNode node, int level, boolean isLast) {
printIndention(level);
stdout.print(isLast ? LAST_NODE_PREFIX : NODE_PREFIX);
if (node.isVisible()) {
stdout.print(node.getDisplayName());
} else {
stdout.print(NOT_VISIBLE_NODE);
}
stdout.print("\n");
}
}