org.antlr.stringtemplate
Class AutoIndentWriter

java.lang.Object
  org.antlr.stringtemplate.AutoIndentWriter

All Implemented Interfaces:

StringTemplateWriter

Direct Known Subclasses:

NoIndentWriter

public class AutoIndentWriter
extends java.lang.Object
implements StringTemplateWriter

Essentially a char filter that knows how to auto-indent output by maintaining a stack of indent levels. I set a flag upon newline and then next nonwhitespace char resets flag and spits out indention. The indent stack is a stack of strings so we can repeat original indent not just the same number of columns (don't have to worry about tabs vs spaces then). Anchors are char positions (tabs won't work) that indicate where all future wraps should justify to. The wrap position is actually the larger of either the last anchor or the indentation level. This is a filter on a Writer. \n is the proper way to say newline for options and templates. Templates can mix them but use \n for sure and options like wrap="\n". ST will generate the right thing. Override the default (locale) newline by passing in a string to the constructor.

Field Summary

protected int[]	anchors Stack of integer anchors (char positions in line); avoid Integer creation overhead.
protected int	anchors_sp
protected boolean	atStartOfLine
protected int	charPosition Track char position in the line (later we can think about tabs).
protected int	charPositionOfStartOfExpr
protected java.util.List	indents stack of indents; use List as it's much faster than Stack.
protected int	lineWidth
protected java.lang.String	newline \n or \r\n?
protected java.io.Writer	out

Fields inherited from interface org.antlr.stringtemplate.StringTemplateWriter

NO_WRAP

Constructor Summary

AutoIndentWriter(java.io.Writer out)

AutoIndentWriter(java.io.Writer out, java.lang.String newline)

Method Summary

int	getIndentationWidth()
protected java.lang.StringBuffer	getIndentString(int spaces)
int	indent()
int	indent(int spaces)
void	popAnchorPoint()
java.lang.String	popIndentation()
void	pushAnchorPoint()
void	pushIndentation(java.lang.String indent) Push even blank (null) indents as they are like scopes; must be able to pop them back off stack.
void	setLineWidth(int lineWidth)
int	write(java.lang.String str) Write out a string literal or attribute expression or expression element.
int	write(java.lang.String str, java.lang.String wrap) Write out a string literal or attribute expression or expression element.
int	writeSeparator(java.lang.String str) Write a separator.
int	writeWrapSeparator(java.lang.String wrap) Because we might need to wrap at a non-atomic string boundary (such as when we wrap in between template applications ]}; wrap>) we need to expose the wrap string writing just like for the separator.

Methods inherited from class java.lang.Object

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

Field Detail

indents

protected java.util.List indents

stack of indents; use List as it's much faster than Stack. Grows from 0..n-1. List

anchors

protected int[] anchors

Stack of integer anchors (char positions in line); avoid Integer creation overhead.

anchors_sp

protected int anchors_sp

newline

protected java.lang.String newline

\n or \r\n?

out

protected java.io.Writer out

atStartOfLine

protected boolean atStartOfLine

charPosition

protected int charPosition

Track char position in the line (later we can think about tabs). Indexed from 0. We want to keep charPosition <= lineWidth. This is the position we are *about* to write not the position last written to.

lineWidth

protected int lineWidth

charPositionOfStartOfExpr

protected int charPositionOfStartOfExpr

Constructor Detail

AutoIndentWriter

public AutoIndentWriter(java.io.Writer out,
                        java.lang.String newline)

AutoIndentWriter

public AutoIndentWriter(java.io.Writer out)

Method Detail

setLineWidth

public void setLineWidth(int lineWidth)

Specified by:

setLineWidth in interface StringTemplateWriter

pushIndentation

public void pushIndentation(java.lang.String indent)

Push even blank (null) indents as they are like scopes; must be able to pop them back off stack. To deal with combined anchors and indentation, force indents to include any current anchor point. If current anchor is beyond current indent width, add the difference to the indent to be added. This prevents a check later to deal with anchors when starting new line.

Specified by:

pushIndentation in interface StringTemplateWriter

popIndentation

public java.lang.String popIndentation()

Specified by:

popIndentation in interface StringTemplateWriter

pushAnchorPoint

public void pushAnchorPoint()

Specified by:

pushAnchorPoint in interface StringTemplateWriter

popAnchorPoint

public void popAnchorPoint()

Specified by:

popAnchorPoint in interface StringTemplateWriter

getIndentationWidth

public int getIndentationWidth()

write

public int write(java.lang.String str)
          throws java.io.IOException

Write out a string literal or attribute expression or expression element.

Specified by:

write in interface StringTemplateWriter

Throws:

java.io.IOException

writeSeparator

public int writeSeparator(java.lang.String str)
                   throws java.io.IOException

Description copied from interface: StringTemplateWriter

Write a separator. Same as write() except that a \n cannot be inserted before emitting a separator.

Specified by:

writeSeparator in interface StringTemplateWriter

Throws:

java.io.IOException

write

public int write(java.lang.String str,
                 java.lang.String wrap)
          throws java.io.IOException

Write out a string literal or attribute expression or expression element. If doing line wrap, then check wrap before emitting this str. If at or beyond desired line width then emit a \n and any indentation before spitting out this str.

Specified by:

write in interface StringTemplateWriter

Throws:

java.io.IOException

writeWrapSeparator

public int writeWrapSeparator(java.lang.String wrap)
                       throws java.io.IOException

Description copied from interface: StringTemplateWriter

Because we might need to wrap at a non-atomic string boundary (such as when we wrap in between template applications ]}; wrap>) we need to expose the wrap string writing just like for the separator.

Specified by:

writeWrapSeparator in interface StringTemplateWriter

Throws:

java.io.IOException

indent

public int indent()
           throws java.io.IOException

Throws:

java.io.IOException

indent

public int indent(int spaces)
           throws java.io.IOException

Throws:

java.io.IOException

getIndentString

protected java.lang.StringBuffer getIndentString(int spaces)