Java™ Platform
Standard Ed. 6

javax.swing.text
Class AbstractWriter

java.lang.Object
  extended by 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.


Field Summary
protected static char NEWLINE
          How the text packages models newlines.
 
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.
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

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

Java™ Platform
Standard Ed. 6

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