org.apache.commons.geometry.core.partitioning.bsp.BSPTreePrinter Maven / Gradle / Ivy
Show all versions of commons-geometry-core Show documentation
/*
* 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.commons.geometry.core.partitioning.bsp;
import org.apache.commons.geometry.core.Point;
import org.apache.commons.geometry.core.partitioning.bsp.BSPTree.Node;
/** Internal class for creating simple string representations of BSP trees.
* @param Point implementation type
* @param Node implementation type
*/
final class BSPTreePrinter, N extends Node
>
implements BSPTreeVisitor
{
/** Line indent string. */
private static final String INDENT = " ";
/** New line character. */
private static final String NEW_LINE = "\n";
/** Entry prefix for nodes on the minus side of their parent. */
private static final String MINUS_CHILD = "[-] ";
/** Entry prefix for nodes on the plus side of their parent. */
private static final String PLUS_CHILD = "[+] ";
/** Ellipsis for truncated representations. */
private static final String ELLIPSIS = "...";
/** Maximum depth of nodes that will be printed. */
private final int maxDepth;
/** Contains the string output. */
private final StringBuilder output = new StringBuilder();
/** Simple constructor.
* @param maxDepth maximum depth of nodes to be printed
*/
BSPTreePrinter(final int maxDepth) {
this.maxDepth = maxDepth;
}
/** {@inheritDoc} */
@Override
public Result visit(final N node) {
final int depth = node.depth();
if (depth <= maxDepth) {
startLine(node);
writeNode(node);
} else if (depth == maxDepth + 1 && node.isPlus()) {
startLine(node);
write(ELLIPSIS);
}
return Result.CONTINUE;
}
/** {@inheritDoc} */
@Override
public Order visitOrder(final N node) {
if (node.depth() > maxDepth + 1) {
return Order.NONE;
}
return Order.NODE_MINUS_PLUS;
}
/** Start a line for the given node.
* @param node the node to begin a line for
*/
private void startLine(final N node) {
if (node.getParent() != null) {
write(NEW_LINE);
}
final int depth = node.depth();
for (int i = 0; i < depth; ++i) {
write(INDENT);
}
}
/** Writes the given node to the output.
* @param node the node to write
*/
private void writeNode(final N node) {
if (node.getParent() != null) {
if (node.isMinus()) {
write(MINUS_CHILD);
} else {
write(PLUS_CHILD);
}
}
write(node.toString());
}
/** Add the given string to the output.
* @param str the string to add
*/
private void write(final String str) {
output.append(str);
}
/** Return the string representation of the visited tree. */
@Override
public String toString() {
return output.toString();
}
}