/*
***************************************************************************************
* Copyright (C) 2006 EsperTech, Inc. All rights reserved. *
* http://www.espertech.com/esper *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
***************************************************************************************
*/
package com.espertech.esper.util;
import java.io.PrintWriter;
/**
* Writer that uses an underlying PrintWriter to indent output text for easy reading.
*/
public class IndentWriter {
private final PrintWriter writer;
private final int deltaIndent;
private int currentIndent;
/**
* Ctor.
*
* @param writer to output to
* @param startIndent is the depth of indent to start
* @param deltaIndent is the number of characters to indent for every incrIndent() call
*/
public IndentWriter(PrintWriter writer, int startIndent, int deltaIndent) {
if (startIndent < 0) {
throw new IllegalArgumentException("Invalid start indent");
}
if (deltaIndent < 0) {
throw new IllegalArgumentException("Invalid delta indent");
}
this.writer = writer;
this.deltaIndent = deltaIndent;
this.currentIndent = startIndent;
}
/**
* Increase the indentation one level.
*/
public void incrIndent() {
currentIndent += deltaIndent;
}
/**
* Decrease the indentation one level.
*/
public void decrIndent() {
currentIndent -= deltaIndent;
}
/**
* Print text to the underlying writer.
*
* @param text to print
*/
public void println(String text) {
int indent = currentIndent;
if (indent < 0) {
indent = 0;
}
writer.println(Indent.indent(indent) + text);
}
}