Class AutoIndentWriter

java.lang.Object

java.io.Writer

java.io.FilterWriter

org.codehaus.janino.util.AutoIndentWriter

All Implemented Interfaces:

Closeable, Flushable, Appendable, AutoCloseable

public class AutoIndentWriter
extends FilterWriter

A FilterWriter that indents lines by processing some control characters in the character stream.

INDENT or UNINDENT may precede lines and indicate that the line and all following lines should be (un)indented by one position.

TABULATORs may appear anywhere in lines and dictate that portions of all following lines should be vertically aligned (see resolveTabs(List)).

Field Summary

Fields

Modifier and Type	Field	Description
static final char	CLEAR_TABULATORS	Special character at the beginning of a line that flushes a tabular layout.
static final char	INDENT	Special character at the beginning of a line that indents the following text by one position.
private int	indentation	The current indentation level; incremented by a INDENT char at the beginning of a line, and decremented by a UNINDENT char at the beginning of a line.
private final StringBuilder	lineBuffer	Buffer for the "current line", including the trailing line break (CR, LF or CRLF).
static final char	TABULATOR	Special character indicating a tabular layout of all following lines until UNINDENT.
private List<StringBuilder>	tabulatorBuffer	Iff non-null, then we are in "tab mode".
private int	tabulatorIndentation	The indentation when tab mode started.
static final char	UNINDENT	Special character at the beginning of a line that unindents the following text by one position.

Fields inherited from class FilterWriter

out

Fields inherited from class Writer

lock

Constructor Summary

Constructors

Constructor	Description
AutoIndentWriter(Writer out)

Method Summary

Modifier and Type	Method	Description
void	close()
void	flush()
private void	flushTabulatorBuffer()
private void	line(String line)
private static void	resolveTabs(List<StringBuilder> lineGroup)	Expands all TABULATORs in the given List of StringBuilders with spaces, so that the characters immediately following the TABULATORs are vertically aligned, like this:
private static String	spaces(int n)
void	write(char[] cbuf, int off, int len)
void	write(int c)
void	write(String str, int off, int len)

Methods inherited from class Writer

append, append, append, nullWriter, write, write

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

TABULATOR

public static final char TABULATOR

Special character indicating a tabular layout of all following lines until UNINDENT.

See Also:

• Constant Field Values

CLEAR_TABULATORS

public static final char CLEAR_TABULATORS

Special character at the beginning of a line that flushes a tabular layout.

See Also:

• Constant Field Values

INDENT

public static final char INDENT

Special character at the beginning of a line that indents the following text by one position.

See Also:

• Constant Field Values

UNINDENT

public static final char UNINDENT

Special character at the beginning of a line that unindents the following text by one position.

See Also:

• Constant Field Values

lineBuffer

private final StringBuilder lineBuffer

Buffer for the "current line", including the trailing line break (CR, LF or CRLF).

indentation

private int indentation

The current indentation level; incremented by a INDENT char at the beginning of a line, and decremented by a UNINDENT char at the beginning of a line.

tabulatorBuffer

@Nullable
private List<StringBuilder> tabulatorBuffer

Iff non-null, then we are in "tab mode". While in tab mode, lines are not printed immediately, but stored in this buffer. Tab mode starts when a line contains a TABULATOR. Tab mode ends when output is unindented beyond the level when tab mode started, or when this writer is closed.

When tab mode ends, all buffered lines are vertically aligned at the TABULATORs and printed.

tabulatorIndentation

private int tabulatorIndentation

The indentation when tab mode started.

Constructor Details

AutoIndentWriter

public AutoIndentWriter(Writer out)

Method Details

write

public void write(@Nullable
 char[] cbuf,
 int off,
 int len)
           throws IOException

Overrides:

write in class FilterWriter

Throws:

IOException

write

public void write(@Nullable
 String str,
 int off,
 int len)
           throws IOException

Overrides:

write in class FilterWriter

Throws:

IOException

write

public void write(int c)
           throws IOException

Overrides:

write in class FilterWriter

Throws:

IOException

line

private void line(String line)
           throws IOException

Throws:

IOException

flushTabulatorBuffer

private void flushTabulatorBuffer()
                           throws IOException

Throws:

IOException

resolveTabs

private static void resolveTabs(List<StringBuilder> lineGroup)

Expands all TABULATORs in the given List of StringBuilders with spaces, so that the characters immediately following the TABULATORs are vertically aligned, like this:

Input:

  a @b @c\r\n
  aa @bb @cc\r\n
  aaa @bbb @ccc\r\n

Output:

  a   b   c\r\n
  aa  bb  cc\r\n
  aaa bbb ccc\r\n

spaces

private static String spaces(int n)

Returns:

a String of n spaces

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class FilterWriter

Throws:

IOException

flush

public void flush()
           throws IOException

Specified by:

flush in interface Flushable

Overrides:

flush in class FilterWriter

Throws:

IOException