/*
* reserved comment block
* DO NOT REMOVE OR ALTER!
*/
/*
* Copyright 1999-2002,2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.sun.org.apache.xml.internal.serialize;
import java.io.Writer;
import java.io.StringWriter;
import java.io.IOException;
/**
* Extends {@link Printer} and adds support for indentation and line
* wrapping.
*
* @author <a href="mailto:arkin@intalio.com">Assaf Arkin</a>
*/
public class IndentPrinter
extends Printer
{
/**
* Holds the currently accumulating text line. This buffer will constantly
* be reused by deleting its contents instead of reallocating it.
*/
private StringBuffer _line;
/**
* Holds the currently accumulating text that follows {@link #_line}.
* When the end of the part is identified by a call to {@link #printSpace}
* or {@link #breakLine}, this part is added to the accumulated line.
*/
private StringBuffer _text;
/**
* Counts how many white spaces come between the accumulated line and the
* current accumulated text. Multiple spaces at the end of the a line
* will not be printed.
*/
private int _spaces;
/**
* Holds the indentation for the current line that is now accumulating in
* memory and will be sent for printing shortly.
*/
private int _thisIndent;
/**
* Holds the indentation for the next line to be printed. After this line is
* printed, {@link #_nextIndent} is assigned to {@link #_thisIndent}.
*/
private int _nextIndent;
public IndentPrinter( Writer writer, OutputFormat format)
{
super( writer, format );
// Initialize everything for a first/second run.
_line = new StringBuffer( 80 );
_text = new StringBuffer( 20 );
_spaces = 0;
_thisIndent = _nextIndent = 0;
}
/**
* Called by any of the DTD handlers to enter DTD mode.
* Once entered, all output will be accumulated in a string
* that can be printed as part of the document's DTD.
* This method may be called any number of time but will only
* have affect the first time it's called. To exist DTD state
* and get the accumulated DTD, call {@link #leaveDTD}.
*/
public void enterDTD()
{
// Can only enter DTD state once. Once we're out of DTD
// state, can no longer re-enter it.
if ( _dtdWriter == null ) {
_line.append( _text );
_text = new StringBuffer( 20 );
flushLine( false );
_dtdWriter = new StringWriter();
_docWriter = _writer;
_writer = _dtdWriter;
}
}
/**
* Called by the root element to leave DTD mode and if any
* DTD parts were printer, will return a string with their
* textual content.
*/
public String leaveDTD()
{
// Only works if we're going out of DTD mode.
if ( _writer == _dtdWriter ) {
_line.append( _text );
_text = new StringBuffer( 20 );
flushLine( false );
_writer = _docWriter;
return _dtdWriter.toString();
} else
return null;
}
/**
* Called to print additional text. Each time this method is called
* it accumulates more text. When a space is printed ({@link
* #printSpace}) all the accumulated text becomes one part and is
* added to the accumulate line. When a line is long enough, it can
* be broken at its text boundary.
*
* @param text The text to print
*/
public void printText( String text )
{
_text.append( text );
}
public void printText( StringBuffer text )
{
_text.append( text.toString() );
}
public void printText( char ch )
{
_text.append( ch );
}
public void printText( char[] chars, int start, int length )
{
_text.append( chars, start, length );
}
/**
* Called to print a single space between text parts that may be
* broken into separate lines. Must not be called to print a space
* when preserving spaces. The text accumulated so far with {@link
* #printText} will be added to the accumulated line, and a space
* separator will be counted. If the line accumulated so far is
* long enough, it will be printed.
*/
public void printSpace()
{
// The line consists of the text accumulated in _line,
// followed by one or more spaces as counted by _spaces,
// followed by more space accumulated in _text:
// - Text is printed and accumulated into _text.
// - A space is printed, so _text is added to _line and
// a space is counted.
// - More text is printed and accumulated into _text.
// - A space is printed, the previous spaces are added
// to _line, the _text is added to _line, and a new
// space is counted.
// If text was accumulated with printText(), then the space
// means we have to move that text into the line and
// start accumulating new text with printText().
if ( _text.length() > 0 ) {
// If the text breaks a line bounary, wrap to the next line.
// The printed line size consists of the indentation we're going
// to use next, the accumulated line so far, some spaces and the
// accumulated text so far.
if ( _format.getLineWidth() > 0 &&
_thisIndent + _line.length() + _spaces + _text.length() > _format.getLineWidth() ) {
flushLine( false );
try {
// Print line and new line, then zero the line contents.
_writer.write( _format.getLineSeparator() );
} catch ( IOException except ) {
// We don't throw an exception, but hold it
// until the end of the document.
if ( _exception == null )
_exception = except;
}
}
// Add as many spaces as we accumulaed before.
// At the end of this loop, _spaces is zero.
while ( _spaces > 0 ) {
_line.append( ' ' );
--_spaces;
}
_line.append( _text );
_text = new StringBuffer( 20 );
}
// Starting a new word: accumulate the text between the line
// and this new word; not a new word: just add another space.
++_spaces;
}
/**
* Called to print a line consisting of the text accumulated so
* far. This is equivalent to calling {@link #printSpace} but
* forcing the line to print and starting a new line ({@link
* #printSpace} will only start a new line if the current line
* is long enough).
*/
public void breakLine()
{
breakLine( false );
}
public void breakLine( boolean preserveSpace )
{
// Equivalent to calling printSpace and forcing a flushLine.
if ( _text.length() > 0 ) {
while ( _spaces > 0 ) {
_line.append( ' ' );
--_spaces;
}
_line.append( _text );
_text = new StringBuffer( 20 );
}
flushLine( preserveSpace );
try {
// Print line and new line, then zero the line contents.
_writer.write( _format.getLineSeparator() );
} catch ( IOException except ) {
// We don't throw an exception, but hold it
// until the end of the document.
if ( _exception == null )
_exception = except;
}
}
/**
* Flushes the line accumulated so far to the writer and get ready
* to accumulate the next line. This method is called by {@link
* #printText} and {@link #printSpace} when the accumulated line plus
* accumulated text are two long to fit on a given line. At the end of
* this method _line is empty and _spaces is zero.
*/
public void flushLine( boolean preserveSpace )
{
int indent;
if ( _line.length() > 0 ) {
try {
if ( _format.getIndenting() && ! preserveSpace ) {
// Make sure the indentation does not blow us away.
indent = _thisIndent;
if ( ( 2 * indent ) > _format.getLineWidth() && _format.getLineWidth() > 0 )
indent = _format.getLineWidth() / 2;
// Print the indentation as spaces and set the current
// indentation to the next expected indentation.
while ( indent > 0 ) {
_writer.write( ' ' );
--indent;
}
}
_thisIndent = _nextIndent;
// There is no need to print the spaces at the end of the line,
// they are simply stripped and replaced with a single line
// separator.
_spaces = 0;
_writer.write( _line.toString() );
_line = new StringBuffer( 40 );
} catch ( IOException except ) {
// We don't throw an exception, but hold it
// until the end of the document.
if ( _exception == null )
_exception = except;
}
}
}
/**
* Flush the output stream. Must be called when done printing
* the document, otherwise some text might be buffered.
*/
public void flush()
{
if ( _line.length() > 0 || _text.length() > 0 )
breakLine();
try {
_writer.flush();
} catch ( IOException except ) {
// We don't throw an exception, but hold it
// until the end of the document.
if ( _exception == null )
_exception = except;
}
}
/**
* Increment the indentation for the next line.
*/
public void indent()
{
_nextIndent += _format.getIndent();
}
/**
* Decrement the indentation for the next line.
*/
public void unindent()
{
_nextIndent -= _format.getIndent();
if ( _nextIndent < 0 )
_nextIndent = 0;
// If there is no current line and we're de-identing then
// this indentation level is actually the next level.
if ( ( _line.length() + _spaces + _text.length() ) == 0 )
_thisIndent = _nextIndent;
}
public int getNextIndent()
{
return _nextIndent;
}
public void setNextIndent( int indent )
{
_nextIndent = indent;
}
public void setThisIndent( int indent )
{
_thisIndent = indent;
}
}