org.stringtemplate.v4

Class AutoIndentWriter

java.lang.Object

org.stringtemplate.v4.AutoIndentWriter

All Implemented Interfaces:

STWriter

Direct Known Subclasses:

NoIndentWriter

public class AutoIndentWriter
extends Object
implements STWriter

Essentially a char filter that knows how to auto-indent output by maintaining a stack of indent levels.

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 \r\n and \n them, but use \n in options like wrap="\n". This writer will render newline characters according to newline. The default value is taken from the line.separator system property, and can be overridden by passing in a String to the appropriate constructor.

Field Summary

Fields

Modifier and Type	Field and Description
int[]	anchors Stack of integer anchors (char positions in line); avoid Integer creation overhead.
int	anchors_sp
boolean	atStartOfLine
int	charIndex The absolute char index into the output of the next char to be written.
int	charPosition Track char position in the line (later we can think about tabs).
List<String>	indents Stack of indents.
int	lineWidth
String	newline \n or \r\n?
Writer	out

Fields inherited from interface org.stringtemplate.v4.STWriter

NO_WRAP

Constructor Summary

Constructors

Constructor and Description
AutoIndentWriter(Writer out)
AutoIndentWriter(Writer out, String newline)

Method Summary

Methods

Modifier and Type	Method and Description
int	indent()
int	index() Return the absolute char index into the output of the char we're about to write.
void	popAnchorPoint()
String	popIndentation()
void	pushAnchorPoint()
void	pushIndentation(String indent)
void	setLineWidth(int lineWidth)
int	write(String str) Write out a string literal or attribute expression or expression element.
int	write(String str, String wrap) Write out a string literal or attribute expression or expression element.
int	writeSeparator(String str) Write a separator.
int	writeWrap(String wrap) Because we evaluate ST instance by invoking Interpreter.exec(STWriter, InstanceScope) again, we can't pass options in.

Methods inherited from class java.lang.Object

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

Field Detail

indents

public List<String> indents

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

anchors

public int[] anchors

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

anchors_sp

public int anchors_sp

newline

public String newline

\n or \r\n?

out

public Writer out

atStartOfLine

public boolean atStartOfLine

charPosition

public 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.

charIndex

public int charIndex

The absolute char index into the output of the next char to be written.

lineWidth

public int lineWidth

Constructor Detail

AutoIndentWriter

public AutoIndentWriter(Writer out,
                String newline)

AutoIndentWriter

public AutoIndentWriter(Writer out)

Method Detail

setLineWidth

public void setLineWidth(int lineWidth)

Specified by:

setLineWidth in interface STWriter

pushIndentation

public void pushIndentation(String indent)

Specified by:

pushIndentation in interface STWriter

popIndentation

public String popIndentation()

Specified by:

popIndentation in interface STWriter

pushAnchorPoint

public void pushAnchorPoint()

Specified by:

pushAnchorPoint in interface STWriter

popAnchorPoint

public void popAnchorPoint()

Specified by:

popAnchorPoint in interface STWriter

index

public int index()

Description copied from interface: STWriter

Return the absolute char index into the output of the char we're about to write. Returns 0 if no char written yet.

Specified by:

index in interface STWriter

write

public int write(String str)
          throws IOException

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

Specified by:

write in interface STWriter

Throws:

IOException

writeSeparator

public int writeSeparator(String str)
                   throws IOException

Description copied from interface: STWriter

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

Specified by:

writeSeparator in interface STWriter

Throws:

IOException

write

public int write(String str,
        String wrap)
          throws IOException

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

If doing line wrap, then check wrap before emitting str. If at or beyond desired line width then emit a newline and any indentation before spitting out str.

Specified by:

write in interface STWriter

Throws:

IOException

writeWrap

public int writeWrap(String wrap)
              throws IOException

Description copied from interface: STWriter

Because we evaluate ST instance by invoking Interpreter.exec(STWriter, InstanceScope) again, we can't pass options in. So the Bytecode.INSTR_WRITE instruction of an applied template (such as when we wrap in between template applications like <data:{v|[<v>]}; wrap>) we need to write the wrap string before calling Interpreter.exec(org.stringtemplate.v4.STWriter, org.stringtemplate.v4.InstanceScope). We expose just like for the separator. See Interpreter.writeObject(org.stringtemplate.v4.STWriter, org.stringtemplate.v4.InstanceScope, java.lang.Object, java.lang.String[]) where it checks for ST instance. If POJO, Interpreter.writePOJO(org.stringtemplate.v4.STWriter, org.stringtemplate.v4.InstanceScope, java.lang.Object, java.lang.String[]) passes wrap to STWriter.write(String str, String wrap). Can't pass to Interpreter.exec(org.stringtemplate.v4.STWriter, org.stringtemplate.v4.InstanceScope).

Specified by:

writeWrap in interface STWriter

Throws:

IOException

indent

public int indent()
           throws IOException

Throws:

IOException