/*
* Copyright 2013 the original author or authors.
*
* 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 org.gradle.internal.text;
import org.gradle.logging.StyledTextOutput;
import org.gradle.logging.internal.AbstractStyledTextOutput;
import org.gradle.logging.internal.LinePrefixingStyledTextOutput;
import org.gradle.util.TreeVisitor;
public class TreeFormatter extends TreeVisitor<String> {
private final StringBuilder buffer = new StringBuilder();
private final AbstractStyledTextOutput original;
private Node current;
public TreeFormatter() {
original = new AbstractStyledTextOutput() {
@Override
protected void doAppend(String text) {
buffer.append(text);
}
};
current = new Node();
}
@Override
public String toString() {
return buffer.toString();
}
@Override
public void node(String node) {
if (current.traversing) {
// First child node
current = new Node(current, node);
if (current.isRoot()) {
original.append(node);
current.valueWritten = true;
}
} else {
// A sibling node
current = new Node(current.parent, node);
}
}
@Override
public void startChildren() {
current.traversing = true;
}
@Override
public void endChildren() {
if (current.parent == null) {
throw new IllegalStateException("Not visiting any node.");
}
if (!current.traversing) {
current = current.parent;
}
if (current.isRoot()) {
writeNode(current);
}
current = current.parent;
}
private void writeNode(Node node) {
if (node.prefix == null) {
node.prefix = node.isRoot() ? "" : node.parent.prefix + " ";
}
StyledTextOutput output = new LinePrefixingStyledTextOutput(original, node.prefix);
if (!node.valueWritten) {
output.append(node.parent.prefix);
output.append(" - ");
output.append(node.value);
}
if (node.canCollapseFirstChild()) {
output.append(": ");
Node firstChild = node.firstChild;
output.append(firstChild.value);
firstChild.valueWritten = true;
firstChild.prefix = node.prefix;
writeNode(firstChild);
} else if (node.firstChild != null) {
original.format(":%n");
writeNode(node.firstChild);
}
if (node.nextSibling != null) {
original.format("%n");
writeNode(node.nextSibling);
}
}
private static class Node {
final Node parent;
final String value;
boolean written;
boolean traversing;
Node firstChild;
Node lastChild;
Node nextSibling;
String prefix;
public boolean valueWritten;
private Node() {
this.parent = null;
this.value = null;
traversing = true;
written = true;
prefix = "";
}
private Node(Node parent, String value) {
this.parent = parent;
this.value = value;
if (parent.firstChild == null) {
parent.firstChild = this;
parent.lastChild = this;
} else {
parent.lastChild.nextSibling = this;
parent.lastChild = this;
}
}
boolean canCollapseFirstChild() {
return firstChild != null && firstChild.nextSibling == null && !firstChild.canCollapseFirstChild();
}
boolean isRoot() {
return parent.parent == null;
}
}
}