com.tangosol.io.IndentingWriter Maven / Gradle / Ivy
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/*
* Copyright (c) 2000, 2020, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* http://oss.oracle.com/licenses/upl.
*/
package com.tangosol.io;
import com.tangosol.util.Base;
import java.io.Writer;
import java.io.PrintWriter;
/**
* An IndentingWriter is used to indent line-based output to an underlying
* Writer.
*
* @author cp 2000.10.17
*/
public class IndentingWriter
extends PrintWriter
{
// ----- constructors ---------------------------------------------------
/**
* Construct an IndentingWriter that indents a certain number of spaces.
*
* @param writer the underlying writer to write to
* @param cSpaces the number of spaces to indent each line with
*/
public IndentingWriter(Writer writer, int cSpaces)
{
this(writer, Base.dup(' ', cSpaces));
}
/**
* Construct an IndentingWriter that indents using an indention string.
*
* @param writer the underlying writer to write to
* @param sIndent the String value to indent each line with
*/
public IndentingWriter(Writer writer, String sIndent)
{
super(writer, true);
Base.azzert(sIndent.indexOf('\n') < 0);
// if this and underlying writers are both indenting writers, combine
// the indentation strings
Class clz = IndentingWriter.class;
if (this.getClass() == clz && writer.getClass() == clz)
{
IndentingWriter that = (IndentingWriter) writer;
sIndent = new StringBuffer().append(that.m_achIndent).append(sIndent).toString();
this.out = that.out;
}
m_achIndent = sIndent.toCharArray();
}
// ----- Writer methods -------------------------------------------------
/**
* Write a single character. The character to be written is contained in
* the 16 low-order bits of the given integer value; the 16 high-order bits
* are ignored.
*
* Subclasses that intend to support efficient single-character output
* should override this method.
*
* @param c int specifying a character to be written.
*/
public void write(int c)
{
synchronized (lock)
{
if (c == '\n')
{
m_fNewline = true;
}
else if (m_fNewline)
{
m_fNewline = false;
if (!m_fSuspended)
{
super.write(m_achIndent);
}
}
super.write(c);
}
}
/**
* Write a portion of an array of characters.
*
* @param cbuf Array of characters
* @param off Offset from which to start writing characters
* @param len Number of characters to write
*/
public void write(char cbuf[], int off, int len)
{
synchronized (lock)
{
for (int i = 0; i < len; ++i)
{
write(cbuf[off++]);
}
}
}
/**
* Write a string.
*
* @param str String to be written
*/
public void write(String str)
{
synchronized (lock)
{
write(str.toCharArray());
}
}
/**
* Write a portion of a string.
*
* @param str A String
* @param off Offset from which to start writing characters
* @param len Number of characters to write
*/
public void write(String str, int off, int len)
{
synchronized (lock)
{
char ach[];
if (len <= MAX_BUF)
{
ach = m_achBuf;
if (ach == null)
{
m_achBuf = ach = new char[MAX_BUF];
}
}
else
{
ach = new char[len];
}
str.getChars(off, (off + len), ach, 0);
write(ach, 0, len);
}
}
// ----- PrintWriter methods --------------------------------------------
/**
* Terminate the current line by writing the line separator string. The
* line separator string is defined by the system property
* line.separator, and is not necessarily a single newline
* character ('\n').
*/
public void println()
{
super.println();
m_fNewline = true;
}
// ----- IndentingWriter methods ----------------------------------------
/**
* Suspends indentation.
*/
public void suspend()
{
m_fSuspended = true;
}
/**
* Resumes indentation.
*/
public void resume()
{
m_fSuspended = false;
}
// ----- data members ---------------------------------------------------
/**
* The characters to use to indent each line.
*/
private char[] m_achIndent;
/**
* True if the IndentingWriter is on a new line.
*/
private boolean m_fNewline = true;
/**
* True if the indentation feature of the IndentingWriter is suspended.
*/
private boolean m_fSuspended = false;
private char[] m_achBuf;
private static final int MAX_BUF = 1024;
}