javax.swing.text
Class AbstractWriter

java.lang.Object
  javax.swing.text.AbstractWriter

Direct Known Subclasses:

HTMLWriter, MinimalHTMLWriter

public abstract class AbstractWriter

extends Object

AbstractWriter is an abstract class that actually does the work of writing out the element tree including the attributes. In terms of how much is written out per line, the writer defaults to 100. But this value can be set by subclasses.

Author:

Sunita Mani

Field Summary

private boolean	canWrapLines True indicates that when writing, the line can be split, false indicates that even if the line is > than max line length it should not be split.
private int	currLength
private Document	doc
private int	endOffset
private char[]	indentChars Used when indenting.
private int	indentLevel
private int	indentSpace
private boolean	isLineEmpty True while the current line is empty.
private ElementIterator	it
private String	lineSeparator String used for end of line.
private int	maxLineLength
protected static char	NEWLINE How the text packages models newlines.
private char[]	newlineChars This is used in writeLineSeparator instead of tempChars.
private int	offsetIndent
private Writer	out
private Segment	segment Used for writing text.
private int	startOffset
private char[]	tempChars Used when writing out a string.

Constructor Summary

protected	AbstractWriter(Writer w, Document doc) Creates a new AbstractWriter.
protected	AbstractWriter(Writer w, Document doc, int pos, int len) Creates a new AbstractWriter.
protected	AbstractWriter(Writer w, Element root) Creates a new AbstractWriter.
protected	AbstractWriter(Writer w, Element root, int pos, int len) Creates a new AbstractWriter.

Method Summary

protected void	decrIndent() Decrements the indent level.
protected boolean	getCanWrapLines() Returns whether or not the lines can be wrapped.
protected int	getCurrentLineLength() Returns the current line length.
protected Document	getDocument() Fetches the document.
protected ElementIterator	getElementIterator() Fetches the ElementIterator.
int	getEndOffset() Returns the last offset to be output.
protected int	getIndentLevel() Returns the current indentation level.
protected int	getIndentSpace() Returns the amount of space to indent.
protected int	getLineLength() Returns the maximum line length.
String	getLineSeparator() Returns the string used to represent newlines.
int	getStartOffset() Returns the first offset to be output.
protected String	getText(Element elem) Returns the text associated with the element.
protected Writer	getWriter() Returns the Writer that is used to output the content.
protected void	incrIndent() Increments the indent level.
protected void	indent() Does indentation.
private int	indexOf(char[] chars, char sChar, int startIndex, int endIndex) Support method to locate an occurence of a particular character.
protected boolean	inRange(Element next) This method determines whether the current element is in the range specified.
protected boolean	isLineEmpty() Returns true if the current line should be considered empty.
protected void	output(char[] content, int start, int length) The last stop in writing out content.
protected void	setCanWrapLines(boolean newValue) Sets whether or not lines can be wrapped.
protected void	setCurrentLineLength(int length) Sets the current line length.
protected void	setIndentSpace(int space) Enables subclasses to specify how many spaces an indent maps to.
protected void	setLineLength(int l) Enables subclasses to set the number of characters they want written per line.
void	setLineSeparator(String value) Sets the String used to reprsent newlines.
protected void	text(Element elem) Writes out text.
protected abstract void	write() This abstract method needs to be implemented by subclasses.
protected void	write(char ch) Writes out a character.
protected void	write(char[] chars, int startIndex, int length) All write methods call into this one.
protected void	write(String content) Writes out a string.
protected void	writeAttributes(AttributeSet attr) Writes out the set of attributes as " =" pairs.
protected void	writeLineSeparator() Writes the line separator.

Methods inherited from class java.lang.Object

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

Field Detail

it

private ElementIterator it

out

private Writer out

indentLevel

private int indentLevel

indentSpace

private int indentSpace

doc

private Document doc

maxLineLength

private int maxLineLength

currLength

private int currLength

startOffset

private int startOffset

endOffset

private int endOffset

offsetIndent

private int offsetIndent

lineSeparator

private String lineSeparator

String used for end of line. If the Document has the property EndOfLineStringProperty, it will be used for newlines. Otherwise the System property line.separator will be used. The line separator can also be set.

canWrapLines

private boolean canWrapLines

True indicates that when writing, the line can be split, false indicates that even if the line is > than max line length it should not be split.

isLineEmpty

private boolean isLineEmpty

True while the current line is empty. This will remain true after indenting.

indentChars

private char[] indentChars

Used when indenting. Will contain the spaces.

tempChars

private char[] tempChars

Used when writing out a string.

newlineChars

private char[] newlineChars

This is used in writeLineSeparator instead of tempChars. If tempChars were used it would mean write couldn't invoke writeLineSeparator as it might have been passed tempChars.

segment

private Segment segment

Used for writing text.

NEWLINE

protected static final char NEWLINE

How the text packages models newlines.

See Also:

getLineSeparator(), Constant Field Values

Constructor Detail

AbstractWriter

protected AbstractWriter(Writer w,
                         Document doc)

Creates a new AbstractWriter. Initializes the ElementIterator with the default root of the document.

Parameters:

w - a Writer.

doc - a Document

AbstractWriter

protected AbstractWriter(Writer w,
                         Document doc,
                         int pos,
                         int len)

Creates a new AbstractWriter. Initializes the ElementIterator with the element passed in.

Parameters:

w - a Writer

doc - an Element

pos - The location in the document to fetch the content.

len - The amount to write out.

AbstractWriter

protected AbstractWriter(Writer w,
                         Element root)

Creates a new AbstractWriter. Initializes the ElementIterator with the element passed in.

Parameters:

w - a Writer

root - an Element

AbstractWriter

protected AbstractWriter(Writer w,
                         Element root,
                         int pos,
                         int len)

Creates a new AbstractWriter. Initializes the ElementIterator with the element passed in.

Parameters:

w - a Writer

root - an Element

pos - The location in the document to fetch the content.

len - The amount to write out.

Method Detail

getStartOffset

public int getStartOffset()

Returns the first offset to be output.

Since:

1.3

getEndOffset

public int getEndOffset()

Returns the last offset to be output.

Since:

1.3

getElementIterator

protected ElementIterator getElementIterator()

Fetches the ElementIterator.

Returns:

the ElementIterator.

getWriter

protected Writer getWriter()

Returns the Writer that is used to output the content.

Since:

1.3

getDocument

protected Document getDocument()

Fetches the document.

Returns:

the Document.

inRange

protected boolean inRange(Element next)

This method determines whether the current element is in the range specified. When no range is specified, the range is initialized to be the entire document. inRange() returns true if the range specified intersects with the element's range.

Parameters:

next - an Element.

Returns:

boolean that indicates whether the element is in the range.

write

protected abstract void write()
                       throws IOException,
                              BadLocationException

This abstract method needs to be implemented by subclasses. Its responsibility is to iterate over the elements and use the write() methods to generate output in the desired format.

Throws:

IOException

BadLocationException

getText

protected String getText(Element elem)
                  throws BadLocationException

Returns the text associated with the element. The assumption here is that the element is a leaf element. Throws a BadLocationException when encountered.

Parameters:

elem - an Element

Returns:

the text as a String

Throws:

BadLocationException - if pos represents an invalid location within the document

text

protected void text(Element elem)
             throws BadLocationException,
                    IOException

Writes out text. If a range is specified when the constructor is invoked, then only the appropriate range of text is written out.

Parameters:

elem - an Element.

Throws:

IOException - on any I/O error

BadLocationException - if pos represents an invalid location within the document.

setLineLength

protected void setLineLength(int l)

Enables subclasses to set the number of characters they want written per line. The default is 100.

Parameters:

l - the maximum line length.

getLineLength

protected int getLineLength()

Returns the maximum line length.

Since:

1.3

setCurrentLineLength

protected void setCurrentLineLength(int length)

Sets the current line length.

Since:

1.3.

getCurrentLineLength

protected int getCurrentLineLength()

Returns the current line length.

Since:

1.3.

isLineEmpty

protected boolean isLineEmpty()

Returns true if the current line should be considered empty. This is true when getCurrentLineLength == 0 || indent has been invoked on an empty line.

Since:

1.3

setCanWrapLines

protected void setCanWrapLines(boolean newValue)

Sets whether or not lines can be wrapped. This can be toggled during the writing of lines. For example, outputting HTML might set this to false when outputting a quoted string.

Since:

1.3

getCanWrapLines

protected boolean getCanWrapLines()

Returns whether or not the lines can be wrapped. If this is false no lineSeparator's will be output.

Since:

1.3

setIndentSpace

protected void setIndentSpace(int space)

Enables subclasses to specify how many spaces an indent maps to. When indentation takes place, the indent level is multiplied by this mapping. The default is 2.

Parameters:

space - an int representing the space to indent mapping.

getIndentSpace

protected int getIndentSpace()

Returns the amount of space to indent.

Since:

1.3

setLineSeparator

public void setLineSeparator(String value)

Sets the String used to reprsent newlines. This is initialized in the constructor from either the Document, or the System property line.separator.

Since:

1.3

getLineSeparator

public String getLineSeparator()

Returns the string used to represent newlines.

Since:

1.3

incrIndent

protected void incrIndent()

Increments the indent level. If indenting would cause getIndentSpace() *getIndentLevel() to be > than getLineLength() this will not cause an indent.

decrIndent

protected void decrIndent()

Decrements the indent level.

getIndentLevel

protected int getIndentLevel()

Returns the current indentation level. That is, the number of times incrIndent has been invoked minus the number of times decrIndent has been invoked.

Since:

1.3

indent

protected void indent()
               throws IOException

Does indentation. The number of spaces written out is indent level times the space to map mapping. If the current line is empty, this will not make it so that the current line is still considered empty.

Throws:

IOException - on any I/O error

write

protected void write(char ch)
              throws IOException

Writes out a character. This is implemented to invoke the write method that takes a char[].

Parameters:

ch - a char.

Throws:

IOException - on any I/O error

write

protected void write(String content)
              throws IOException

Writes out a string. This is implemented to invoke the write method that takes a char[].

Parameters:

content - a String.

Throws:

IOException - on any I/O error

writeLineSeparator

protected void writeLineSeparator()
                           throws IOException

Writes the line separator. This invokes output directly as well as setting the lineLength to 0.

Throws:

IOException

Since:

1.3

write

protected void write(char[] chars,
                     int startIndex,
                     int length)
              throws IOException

All write methods call into this one. If getCanWrapLines() returns false, this will call output with each sequence of chars that doesn't contain a NEWLINE, followed by a call to writeLineSeparator. On the other hand, if getCanWrapLines() returns true, this will split the string, as necessary, so getLineLength is honored. The only exception is if the current string contains no whitespace, and won't fit in which case the line length will exceed getLineLength.

Throws:

IOException

Since:

1.3

writeAttributes

protected void writeAttributes(AttributeSet attr)
                        throws IOException

Writes out the set of attributes as " =" pairs. It throws an IOException when encountered.

Parameters:

attr - an AttributeSet.

Throws:

IOException - on any I/O error

output

protected void output(char[] content,
                      int start,
                      int length)
               throws IOException

The last stop in writing out content. All the write methods eventually make it to this method, which invokes write on the Writer.

This method also updates the line length based on length. If this is invoked to output a newline, the current line length will need to be reset as will no longer be valid. If it is up to the caller to do this. Use writeLineSeparator to write out a newline, which will property update the current line length.

Throws:

IOException

Since:

1.3

indexOf

private int indexOf(char[] chars,
                    char sChar,
                    int startIndex,
                    int endIndex)

Support method to locate an occurence of a particular character.