jaxp/src/com/sun/org/apache/xml/internal/serialize/IndentPrinter.java
changeset 12457 c348e06f0e82
parent 6 7f561c08de6b
child 25834 aba3efbf4ec5
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jaxp/src/com/sun/org/apache/xml/internal/serialize/IndentPrinter.java	Thu Apr 12 08:38:26 2012 -0700
@@ -0,0 +1,365 @@
+/*
+ * 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;
+    }
+
+
+}