content: /*******************************************************************************
   * Copyright (c) 2000, 2010 IBM Corporation and others.
   * All rights reserved. This program and the accompanying materials
   * are made available under the terms of the Eclipse Public License v1.0
   * which accompanies this distribution, and is available at
   * http://www.eclipse.org/legal/epl-v10.html
   *
   * Contributors:
   *     IBM Corporation - initial API and implementation
   *******************************************************************************/
  package org.eclipse.wst.jsdt.internal.ui.text;
  
  import org.eclipse.core.runtime.Assert;
  import org.eclipse.jface.text.BadLocationException;
  import org.eclipse.jface.text.IDocument;
  import org.eclipse.jface.text.IRegion;
  import org.eclipse.wst.jsdt.core.IJavaScriptProject;
  import org.eclipse.wst.jsdt.core.JavaScriptCore;
  import org.eclipse.wst.jsdt.core.formatter.DefaultCodeFormatterConstants;
  import org.eclipse.wst.jsdt.internal.corext.util.CodeFormatterUtil;
  
  
  /**
   * Uses the {@link org.eclipse.wst.jsdt.internal.ui.text.JavaHeuristicScanner} to
   * get the indentation level for a certain position in a document.
   *
   * <p>
   * An instance holds some internal position in the document and is therefore
   * not threadsafe.
   * </p>
   *
   * 
   */
  public final class JavaIndenter {
  	
  	/**
  	 * The JDT Core preferences.
  	 * 
  	 */
  	private final class CorePrefs {
  		final boolean prefUseTabs;
  		final int prefTabSize;
  		final int prefIndentationSize;
  		final boolean prefArrayDimensionsDeepIndent;
  		final int prefArrayIndent;
  		final boolean prefArrayDeepIndent;
  		final boolean prefTernaryDeepAlign;
  		final int prefTernaryIndent;
  		final int prefCaseIndent;
  		final int prefAssignmentIndent;
  		final int prefCaseBlockIndent;
  		final int prefSimpleIndent;
  		final int prefBracketIndent;
  		final boolean prefMethodDeclDeepIndent;
  		final int prefMethodDeclIndent;
  		final boolean prefMethodCallDeepIndent;
  		final int prefMethodCallIndent;
  		final boolean prefParenthesisDeepIndent;
  		final int prefParenthesisIndent;
  		final int prefBlockIndent;
  		final int prefMethodBodyIndent;
  		final int prefTypeIndent;
  		final boolean prefIndentBracesForBlocks;
  		final boolean prefIndentBracesForArrays;
  		final boolean prefIndentBracesForMethods;
  		final boolean prefIndentBracesForTypes;
  		final int prefContinuationIndent;
  		final boolean prefHasGenerics;
  		final String prefTabChar;
  		
  		private final IJavaScriptProject fProject;
  
  		/**
  		 * Returns <code>true</code> if the class is used outside the workbench,
  		 * <code>false</code> in normal mode
  		 *
  		 * @return <code>true</code> if the plug-ins are not available
  		 */
  		private boolean isStandalone() {
  			return JavaScriptCore.getPlugin() == null;
  		}
  		
  		/**
  		 * Returns the possibly project-specific core preference defined under <code>key</code>.
  		 *
  		 * @param key the key of the preference
  		 * @return the value of the preference
  		 * 
  		 */
  		private String getCoreFormatterOption(String key) {
  			if (fProject == null)
  				return JavaScriptCore.getOption(key);
  			return fProject.getOption(key, true);
  		}
  		
  		CorePrefs(IJavaScriptProject project) {
  			fProject= project;
  			if (isStandalone()) {
  				prefUseTabs= true;
  				prefTabSize= 4;
  				prefIndentationSize= 4;
  				prefArrayDimensionsDeepIndent= true;
  				prefContinuationIndent= 2;
  				prefBlockIndent= 1;
  				prefArrayIndent= prefContinuationIndent;
  				prefArrayDeepIndent= true;
  				prefTernaryDeepAlign= false;
  				prefTernaryIndent= prefContinuationIndent;
  				prefCaseIndent= 0;
  				prefAssignmentIndent= prefBlockIndent;
  				prefCaseBlockIndent= prefBlockIndent;
  				prefIndentBracesForBlocks= false;
  				prefSimpleIndent= (prefIndentBracesForBlocks && prefBlockIndent == 0) ? 1 : prefBlockIndent;
  				prefBracketIndent= prefBlockIndent;
  				prefMethodDeclDeepIndent= true;
  				prefMethodDeclIndent= 1;
  				prefMethodCallDeepIndent= false;
  				prefMethodCallIndent= 1;
  				prefParenthesisDeepIndent= false;
  				prefParenthesisIndent= prefContinuationIndent;
  				prefMethodBodyIndent= 1;
  				prefTypeIndent= 1;
  				prefIndentBracesForArrays= false;
  				prefIndentBracesForMethods= false;
  				prefIndentBracesForTypes= false;
  				prefHasGenerics= false;
  				prefTabChar= JavaScriptCore.TAB;
  			} else {
  				prefUseTabs= prefUseTabs();
  				prefTabSize= prefTabSize();
  				prefIndentationSize= prefIndentationSize();
  				prefArrayDimensionsDeepIndent= prefArrayDimensionsDeepIndent();
  				prefContinuationIndent= prefContinuationIndent();
  				prefBlockIndent= prefBlockIndent();
  				prefArrayIndent= prefArrayIndent();
  				prefArrayDeepIndent= prefArrayDeepIndent();
  				prefTernaryDeepAlign= prefTernaryDeepAlign();
  				prefTernaryIndent= prefTernaryIndent();
  				prefCaseIndent= prefCaseIndent();
  				prefAssignmentIndent= prefAssignmentIndent();
  				prefCaseBlockIndent= prefCaseBlockIndent();
  				prefIndentBracesForBlocks= prefIndentBracesForBlocks();
  				prefSimpleIndent= prefSimpleIndent();
  				prefBracketIndent= prefBracketIndent();
  				prefMethodDeclDeepIndent= prefMethodDeclDeepIndent();
  				prefMethodDeclIndent= prefMethodDeclIndent();
  				prefMethodCallDeepIndent= prefMethodCallDeepIndent();
  				prefMethodCallIndent= prefMethodCallIndent();
  				prefParenthesisDeepIndent= prefParenthesisDeepIndent();
  				prefParenthesisIndent= prefParenthesisIndent();
  				prefMethodBodyIndent= prefMethodBodyIndent();
  				prefTypeIndent= prefTypeIndent();
  				prefIndentBracesForArrays= prefIndentBracesForArrays();
  				prefIndentBracesForMethods= prefIndentBracesForMethods();
  				prefIndentBracesForTypes= prefIndentBracesForTypes();
  				prefHasGenerics= hasGenerics();
  				prefTabChar= getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_TAB_CHAR);
  			}
  		}
  		
  		private boolean prefUseTabs() {
  			return !JavaScriptCore.SPACE.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_TAB_CHAR));
  		}
  
  		private int prefTabSize() {
  			return CodeFormatterUtil.getTabWidth(fProject);
  		}
  
  		private int prefIndentationSize() {
  			return CodeFormatterUtil.getIndentWidth(fProject);
  		}
  
  		private boolean prefArrayDimensionsDeepIndent() {
  			return true; // sensible default, no formatter setting
  		}
  
  		private int prefArrayIndent() {
  			String option= getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_EXPRESSIONS_IN_ARRAY_INITIALIZER);
  			try {
  				if (DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_BY_ONE)
  					return 1;
  			} catch (IllegalArgumentException e) {
  				// ignore and return default
  			}
  
  			return prefContinuationIndent(); // default
  		}
  
  		private boolean prefArrayDeepIndent() {
  			String option= getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_EXPRESSIONS_IN_ARRAY_INITIALIZER);
  			try {
  				return DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_ON_COLUMN;
  			} catch (IllegalArgumentException e) {
  				// ignore and return default
  			}
  
  			return true;
  		}
  
  		private boolean prefTernaryDeepAlign() {
  			String option= getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_CONDITIONAL_EXPRESSION);
  			try {
  				return DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_ON_COLUMN;
  			} catch (IllegalArgumentException e) {
  				// ignore and return default
  			}
  			return false;
  		}
  
  		private int prefTernaryIndent() {
  			String option= getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_CONDITIONAL_EXPRESSION);
  			try {
  				if (DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_BY_ONE)
  					return 1;
  				else
  					return prefContinuationIndent();
  			} catch (IllegalArgumentException e) {
  				// ignore and return default
  			}
  
  			return prefContinuationIndent();
  		}
  
  		private int prefCaseIndent() {
  			if (DefaultCodeFormatterConstants.TRUE.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_INDENT_SWITCHSTATEMENTS_COMPARE_TO_SWITCH)))
  				return prefBlockIndent();
  			else
  				return 0;
  		}
  
  		private int prefAssignmentIndent() {
  			return prefBlockIndent();
  		}
  
  		private int prefCaseBlockIndent() {
  			if (true)
  				return prefBlockIndent();
  
  			if (DefaultCodeFormatterConstants.TRUE.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_INDENT_SWITCHSTATEMENTS_COMPARE_TO_CASES)))
  				return prefBlockIndent();
  			else
  				return 0;
  		}
  
  		private int prefSimpleIndent() {
  			if (prefIndentBracesForBlocks() && prefBlockIndent() == 0)
  				return 1;
  			else return prefBlockIndent();
  		}
  
  		private int prefBracketIndent() {
  			return prefBlockIndent();
  		}
  
  		private boolean prefMethodDeclDeepIndent() {
  			String option= getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_PARAMETERS_IN_METHOD_DECLARATION);
  			try {
  				return DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_ON_COLUMN;
  			} catch (IllegalArgumentException e) {
  				// ignore and return default
  			}
  
  			return true;
  		}
  
  		private int prefMethodDeclIndent() {
  			String option= getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_PARAMETERS_IN_METHOD_DECLARATION);
  			try {
  				if (DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_BY_ONE)
  					return 1;
  				else
  					return prefContinuationIndent();
  			} catch (IllegalArgumentException e) {
  				// ignore and return default
  			}
  			return 1;
  		}
  
  		private boolean prefMethodCallDeepIndent() {
  			String option= getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_ARGUMENTS_IN_METHOD_INVOCATION);
  			try {
  				return DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_ON_COLUMN;
  			} catch (IllegalArgumentException e) {
  				// ignore and return default
  			}
  			return false; // sensible default
  		}
  
  		private int prefMethodCallIndent() {
  			String option= getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_ARGUMENTS_IN_METHOD_INVOCATION);
  			try {
  				if (DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_BY_ONE)
  					return 1;
  				else
  					return prefContinuationIndent();
  			} catch (IllegalArgumentException e) {
  				// ignore and return default
  			}
  
  			return 1; // sensible default
  		}
  
  		private boolean prefParenthesisDeepIndent() {
  			if (true) // don't do parenthesis deep indentation
  				return false;
  
  			String option= getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_CONTINUATION_INDENTATION);
  			try {
  				return DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_ON_COLUMN;
  			} catch (IllegalArgumentException e) {
  				// ignore and return default
  			}
  
  			return false; // sensible default
  		}
  
  		private int prefParenthesisIndent() {
  			return prefContinuationIndent();
  		}
  
  		private int prefBlockIndent() {
  			String option= getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_INDENT_STATEMENTS_COMPARE_TO_BLOCK);
  			if (DefaultCodeFormatterConstants.FALSE.equals(option))
  				return 0;
  
  			return 1; // sensible default
  		}
  
  		private int prefMethodBodyIndent() {
  			if (DefaultCodeFormatterConstants.FALSE.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_INDENT_STATEMENTS_COMPARE_TO_BODY)))
  				return 0;
  
  			return 1; // sensible default
  		}
  
  		private int prefTypeIndent() {
  			String option= getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_INDENT_BODY_DECLARATIONS_COMPARE_TO_TYPE_HEADER);
  			if (DefaultCodeFormatterConstants.FALSE.equals(option))
  				return 0;
  
  			return 1; // sensible default
  		}
  
  		private boolean prefIndentBracesForBlocks() {
  			return DefaultCodeFormatterConstants.NEXT_LINE_SHIFTED.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_BLOCK));
  		}
  
  		private boolean prefIndentBracesForArrays() {
  			return DefaultCodeFormatterConstants.NEXT_LINE_SHIFTED.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_ARRAY_INITIALIZER));
  		}
  
  		private boolean prefIndentBracesForMethods() {
  			return DefaultCodeFormatterConstants.NEXT_LINE_SHIFTED.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_METHOD_DECLARATION));
  		}
  
  		private boolean prefIndentBracesForTypes() {
  			return DefaultCodeFormatterConstants.NEXT_LINE_SHIFTED.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_TYPE_DECLARATION));
  		}
  
  		private int prefContinuationIndent() {
  			try {
  				return Integer.parseInt(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_CONTINUATION_INDENTATION));
  			} catch (NumberFormatException e) {
  				// ignore and return default
  			}
  
  			return 2; // sensible default
  		}
  		private boolean hasGenerics() {
  			return JavaScriptCore.VERSION_1_5.compareTo(getCoreFormatterOption(JavaScriptCore.COMPILER_SOURCE)) <= 0;
  		}
  	}
  
  	/** The document being scanned. */
  	private final IDocument fDocument;
  	/** The indentation accumulated by <code>findReferencePosition</code>. */
  	private int fIndent;
  	/**
  	 * The absolute (character-counted) indentation offset for special cases
  	 * (method defs, array initializers)
  	 */
  	private int fAlign;
  	/** The stateful scanposition for the indentation methods. */
  	private int fPosition;
  	/** The previous position. */
  	private int fPreviousPos;
  	/** The most recent token. */
  	private int fToken;
  	/** The line of <code>fPosition</code>. */
  	private int fLine;
  	/**
  	 * The scanner we will use to scan the document. It has to be installed
  	 * on the same document as the one we get.
  	 */
  	private final JavaHeuristicScanner fScanner;
  	/**
  	 * The JDT Core preferences.
  	 * 
  	 */
  	private final CorePrefs fPrefs;
  
  	/**
  	 * Creates a new instance.
  	 *
  	 * @param document the document to scan
  	 * @param scanner the {@link JavaHeuristicScanner} to be used for scanning
  	 * the document. It must be installed on the same <code>IDocument</code>.
  	 */
  	public JavaIndenter(IDocument document, JavaHeuristicScanner scanner) {
  		this(document, scanner, null);
  	}
  
  	/**
  	 * Creates a new instance.
  	 *
  	 * @param document the document to scan
  	 * @param scanner the {@link JavaHeuristicScanner}to be used for scanning
  	 *        the document. It must be installed on the same
  	 *        <code>IDocument</code>.
  	 * @param project the java project to get the formatter preferences from, or
  	 *        <code>null</code> to use the workspace settings
  	 * 
  	 */
  	public JavaIndenter(IDocument document, JavaHeuristicScanner scanner, IJavaScriptProject project) {
  		Assert.isNotNull(document);
  		Assert.isNotNull(scanner);
  		fDocument= document;
  		fScanner= scanner;
  		fPrefs= new CorePrefs(project);
  	}
  
  	/**
  	 * Computes the indentation at the reference point of <code>position</code>.
  	 *
  	 * @param offset the offset in the document
  	 * @return a String which reflects the indentation at the line in which the
  	 *         reference position to <code>offset</code> resides, or <code>null</code>
  	 *         if it cannot be determined
  	 */
  	public StringBuffer getReferenceIndentation(int offset) {
  		return getReferenceIndentation(offset, false);
  	}
  
  	/**
  	 * Computes the indentation at the reference point of <code>position</code>.
  	 *
  	 * @param offset the offset in the document
  	 * @param assumeOpeningBrace <code>true</code> if an opening brace should be assumed
  	 * @return a String which reflects the indentation at the line in which the
  	 *         reference position to <code>offset</code> resides, or <code>null</code>
  	 *         if it cannot be determined
  	 */
  	private StringBuffer getReferenceIndentation(int offset, boolean assumeOpeningBrace) {
  
  		int unit;
  		if (assumeOpeningBrace)
  			unit= findReferencePosition(offset, Symbols.TokenLBRACE);
  		else
  			unit= findReferencePosition(offset, peekChar(offset));
  
  		// if we were unable to find anything, return null
  		if (unit == JavaHeuristicScanner.NOT_FOUND)
  			return null;
  
  		return getLeadingWhitespace(unit);
  
  	}
  
  	/**
  	 * Computes the indentation at <code>offset</code>.
  	 *
  	 * @param offset the offset in the document
  	 * @return a String which reflects the correct indentation for the line in
  	 *         which offset resides, or <code>null</code> if it cannot be
  	 *         determined
  	 */
  	public StringBuffer computeIndentation(int offset) {
  		return computeIndentation(offset, false);
  	}
  
  	/**
  	 * Computes the indentation at <code>offset</code>.
  	 *
  	 * @param offset the offset in the document
  	 * @param assumeOpeningBrace <code>true</code> if an opening brace should be assumed
  	 * @return a String which reflects the correct indentation for the line in
  	 *         which offset resides, or <code>null</code> if it cannot be
  	 *         determined
  	 */
  	public StringBuffer computeIndentation(int offset, boolean assumeOpeningBrace) {
  
  		StringBuffer reference= getReferenceIndentation(offset, assumeOpeningBrace);
  
  		// handle special alignment
  		if (fAlign != JavaHeuristicScanner.NOT_FOUND) {
  			try {
  				// a special case has been detected.
  				IRegion line= fDocument.getLineInformationOfOffset(fAlign);
  				int lineOffset= line.getOffset();
  				return createIndent(lineOffset, fAlign, false);
  			} catch (BadLocationException e) {
  				return null;
  			}
  		}
  
  		if (reference == null)
  			return null;
  
  		// add additional indent
  		return createReusingIndent(reference, fIndent);
  	}
  
  	/**
  	 * Computes the length of a <code>CharacterSequence</code>, counting
  	 * a tab character as the size until the next tab stop and every other
  	 * character as one.
  	 *
  	 * @param indent the string to measure
  	 * @return the visual length in characters
  	 */
  	private int computeVisualLength(CharSequence indent) {
  		final int tabSize= fPrefs.prefTabSize;
  		int length= 0;
  		for (int i= 0; i < indent.length(); i++) {
  			char ch= indent.charAt(i);
  			switch (ch) {
  				case '\t':
  					if (tabSize > 0) {
  						int reminder= length % tabSize;
  						length += tabSize - reminder;
  					}
  					break;
  				case ' ':
  					length++;
  					break;
  			}
  		}
  		return length;
  	}
  
  	/**
  	 * Strips any characters off the end of <code>reference</code> that exceed
  	 * <code>indentLength</code>.
  	 *
  	 * @param reference the string to measure
  	 * @param indentLength the maximum visual indentation length
  	 * @return the stripped <code>reference</code>
  	 */
  	private StringBuffer stripExceedingChars(StringBuffer reference, int indentLength) {
  		final int tabSize= fPrefs.prefTabSize;
  		int measured= 0;
  		int chars= reference.length();
  		int i= 0;
  		for (; measured < indentLength && i < chars; i++) {
  			char ch= reference.charAt(i);
  			switch (ch) {
  				case '\t':
  					if (tabSize > 0) {
  						int reminder= measured % tabSize;
  						measured += tabSize - reminder;
  					}
  					break;
  				case ' ':
  					measured++;
  					break;
  			}
  		}
  		int deleteFrom= measured > indentLength ? i - 1 : i;
  
  		return reference.delete(deleteFrom, chars);
  	}
  
  	/**
  	 * Returns the indentation of the line at <code>offset</code> as a
  	 * <code>StringBuffer</code>. If the offset is not valid, the empty string
  	 * is returned.
  	 *
  	 * @param offset the offset in the document
  	 * @return the indentation (leading whitespace) of the line in which
  	 * 		   <code>offset</code> is located
  	 */
  	private StringBuffer getLeadingWhitespace(int offset) {
  		StringBuffer indent= new StringBuffer();
  		try {
  			IRegion line= fDocument.getLineInformationOfOffset(offset);
  			int lineOffset= line.getOffset();
  			int nonWS= fScanner.findNonWhitespaceForwardInAnyPartition(lineOffset, lineOffset + line.getLength());
  			indent.append(fDocument.get(lineOffset, nonWS - lineOffset));
  			return indent;
  		} catch (BadLocationException e) {
  			return indent;
  		}
  	}
  
  	/**
  	 * Creates an indentation string of the length indent - start, consisting of
  	 * the content in <code>fDocument</code> in the range [start, indent),
  	 * with every character replaced by a space except for tabs, which are kept
  	 * as such.
  	 * <p>
  	 * If <code>convertSpaceRunsToTabs</code> is <code>true</code>, every
  	 * run of the number of spaces that make up a tab are replaced by a tab
  	 * character. If it is not set, no conversion takes place, but tabs in the
  	 * original range are still copied verbatim.
  	 * </p>
  	 *
  	 * @param start the start of the document region to copy the indent from
  	 * @param indent the exclusive end of the document region to copy the indent
  	 *        from
  	 * @param convertSpaceRunsToTabs whether to convert consecutive runs of
  	 *        spaces to tabs
  	 * @return the indentation corresponding to the document content specified
  	 *         by <code>start</code> and <code>indent</code>
  	 */
  	private StringBuffer createIndent(int start, final int indent, final boolean convertSpaceRunsToTabs) {
  		final boolean convertTabs= fPrefs.prefUseTabs && convertSpaceRunsToTabs;
  		final int tabLen= fPrefs.prefTabSize;
  		final StringBuffer ret= new StringBuffer();
  		try {
  			int spaces= 0;
  			while (start < indent) {
  
  				char ch= fDocument.getChar(start);
  				if (ch == '\t') {
  					ret.append('\t');
  					spaces= 0;
  				} else if (convertTabs) {
  					spaces++;
  					if (spaces == tabLen) {
  						ret.append('\t');
  						spaces= 0;
  					}
  				} else {
  					ret.append(' ');
  				}
  
  				start++;
  			}
  			// remainder
  			while (spaces-- > 0)
  				ret.append(' ');
  
  		} catch (BadLocationException e) {
  		}
  
  		return ret;
  	}
  
  	/**
  	 * Creates a string with a visual length of the given
  	 * <code>indentationSize</code>.
  	 *
  	 * @param buffer the original indent to reuse if possible
  	 * @param additional the additional indentation units to add or subtract to
  	 *        reference
  	 * @return the modified <code>buffer</code> reflecting the indentation
  	 *         adapted to <code>additional</code>
  	 */
  	private StringBuffer createReusingIndent(StringBuffer buffer, int additional) {
  		int refLength= computeVisualLength(buffer);
  		int addLength= fPrefs.prefIndentationSize * additional; // may be < 0
  		int totalLength= Math.max(0, refLength + addLength);
  
  
  		// copy the reference indentation for the indent up to the last tab
  		// stop within the maxCopy area
  		int minLength= Math.min(totalLength, refLength);
  		int tabSize= fPrefs.prefTabSize;
  		int maxCopyLength= tabSize > 0 ? minLength - minLength % tabSize : minLength; // maximum indent to copy
  		stripExceedingChars(buffer, maxCopyLength);
  
  
  		// add additional indent
  		int missing= totalLength - maxCopyLength;
  		final int tabs, spaces;
  		if (JavaScriptCore.SPACE.equals(fPrefs.prefTabChar)) {
  			tabs= 0;
  			spaces= missing;
  		} else if (JavaScriptCore.TAB.equals(fPrefs.prefTabChar)) {
  			tabs= tabSize > 0 ? missing / tabSize : 0;
  			spaces= tabSize > 0 ? missing % tabSize : missing;
  		} else if (DefaultCodeFormatterConstants.MIXED.equals(fPrefs.prefTabChar)) {
  			tabs= tabSize > 0 ? missing / tabSize : 0;
  			spaces= tabSize > 0 ? missing % tabSize : missing;
  		} else {
  			Assert.isTrue(false);
  			return null;
  		}
  		for(int i= 0; i < tabs; i++)
  			buffer.append('\t');
  		for(int i= 0; i < spaces; i++)
  			buffer.append(' ');
  		return buffer;
  	}
  
  	/**
  	 * Returns the reference position regarding to indentation for <code>offset</code>,
  	 * or <code>NOT_FOUND</code>. This method calls
  	 * {@link #findReferencePosition(int, int) findReferencePosition(offset, nextChar)} where
  	 * <code>nextChar</code> is the next character after <code>offset</code>.
  	 *
  	 * @param offset the offset for which the reference is computed
  	 * @return the reference statement relative to which <code>offset</code>
  	 *         should be indented, or {@link JavaHeuristicScanner#NOT_FOUND}
  	 */
  	public int findReferencePosition(int offset) {
  		return findReferencePosition(offset, peekChar(offset));
  	}
  
  	/**
  	 * Peeks the next char in the document that comes after <code>offset</code>
  	 * on the same line as <code>offset</code>.
  	 *
  	 * @param offset the offset into document
  	 * @return the token symbol of the next element, or TokenEOF if there is none
  	 */
  	private int peekChar(int offset) {
  		if (offset < fDocument.getLength()) {
  			try {
  				IRegion line= fDocument.getLineInformationOfOffset(offset);
  				int lineOffset= line.getOffset();
  				int next= fScanner.nextToken(offset, lineOffset + line.getLength());
  				return next;
  			} catch (BadLocationException e) {
  			}
  		}
  		return Symbols.TokenEOF;
  	}
  
  	/**
  	 * Returns the reference position regarding to indentation for <code>position</code>,
  	 * or <code>NOT_FOUND</code>.
  	 *
  	 * <p>If <code>peekNextChar</code> is <code>true</code>, the next token after
  	 * <code>offset</code> is read and taken into account when computing the
  	 * indentation. Currently, if the next token is the first token on the line
  	 * (i.e. only preceded by whitespace), the following tokens are specially
  	 * handled:
  	 * <ul>
  	 * 	<li><code>switch</code> labels are indented relative to the switch block</li>
  	 * 	<li>opening curly braces are aligned correctly with the introducing code</li>
  	 * 	<li>closing curly braces are aligned properly with the introducing code of
  	 * 		the matching opening brace</li>
  	 * 	<li>closing parenthesis' are aligned with their opening peer</li>
  	 * 	<li>the <code>else</code> keyword is aligned with its <code>if</code>, anything
  	 * 		else is aligned normally (i.e. with the base of any introducing statements).</li>
  	 *  <li>if there is no token on the same line after <code>offset</code>, the indentation
  	 * 		is the same as for an <code>else</code> keyword</li>
  	 * </ul>
  	 *
  	 * @param offset the offset for which the reference is computed
  	 * @param nextToken the next token to assume in the document
  	 * @return the reference statement relative to which <code>offset</code>
  	 *         should be indented, or {@link JavaHeuristicScanner#NOT_FOUND}
  	 */
  	public int findReferencePosition(int offset, int nextToken) {
  		boolean danglingElse= false;
  		boolean unindent= false;
  		boolean indent= false;
  		boolean matchBrace= false;
  		boolean matchParen= false;
  		boolean matchCase= false;
  
  		// account for un-indentation characters already typed in, but after position
  		// if they are on a line by themselves, the indentation gets adjusted
  		// accordingly
  		//
  		// also account for a dangling else
  		if (offset < fDocument.getLength()) {
  			try {
  				IRegion line= fDocument.getLineInformationOfOffset(offset);
  				int lineOffset= line.getOffset();
  				int prevPos= Math.max(offset - 1, 0);
  				boolean isFirstTokenOnLine= fDocument.get(lineOffset, prevPos + 1 - lineOffset).trim().length() == 0;
  				int prevToken= fScanner.previousToken(prevPos, JavaHeuristicScanner.UNBOUND);
  				boolean bracelessBlockStart= fScanner.isBracelessBlockStart(prevPos, JavaHeuristicScanner.UNBOUND);
  
  				switch (nextToken) {
  					case Symbols.TokenELSE:
  						danglingElse= true;
  						break;
  					case Symbols.TokenCASE:
  					case Symbols.TokenDEFAULT:
  						if (isFirstTokenOnLine)
  							matchCase= true;
  						break;
  					case Symbols.TokenLBRACE: // for opening-brace-on-new-line style
  						if (bracelessBlockStart && !fPrefs.prefIndentBracesForBlocks)
  							unindent= true;
  						else if ((prevToken == Symbols.TokenCOLON || prevToken == Symbols.TokenEQUAL || prevToken == Symbols.TokenRBRACKET) && !fPrefs.prefIndentBracesForArrays)
  							unindent= true;
  						else if (!bracelessBlockStart && fPrefs.prefIndentBracesForMethods)
  							indent= true;
  						break;
  					case Symbols.TokenRBRACE: // closing braces get unindented
  						if (isFirstTokenOnLine)
  							matchBrace= true;
  						break;
  					case Symbols.TokenRPAREN:
  						if (isFirstTokenOnLine)
  							matchParen= true;
  						break;
  				}
  			} catch (BadLocationException e) {
  			}
  		} else {
  			// don't assume an else could come if we are at the end of file
  			danglingElse= false;
  		}
  
  		int ref= findReferencePosition(offset, danglingElse, matchBrace, matchParen, matchCase);
  		if (unindent)
  			fIndent--;
  		if (indent)
  			fIndent++;
  		return ref;
  	}
  
  	/**
  	 * Returns the reference position regarding to indentation for <code>position</code>,
  	 * or <code>NOT_FOUND</code>.<code>fIndent</code> will contain the
  	 * relative indentation (in indentation units, not characters) after the
  	 * call. If there is a special alignment (e.g. for a method declaration
  	 * where parameters should be aligned), <code>fAlign</code> will contain
  	 * the absolute position of the alignment reference in <code>fDocument</code>,
  	 * otherwise <code>fAlign</code> is set to <code>JavaHeuristicScanner.NOT_FOUND</code>.
  	 *
  	 * @param offset the offset for which the reference is computed
  	 * @param danglingElse whether a dangling else should be assumed at <code>position</code>
  	 * @param matchBrace whether the position of the matching brace should be
  	 *            returned instead of doing code analysis
  	 * @param matchParen whether the position of the matching parenthesis
  	 *            should be returned instead of doing code analysis
  	 * @param matchCase whether the position of a switch statement reference
  	 *            should be returned (either an earlier case statement or the
  	 *            switch block brace)
  	 * @return the reference statement relative to which <code>position</code>
  	 *         should be indented, or {@link JavaHeuristicScanner#NOT_FOUND}
  	 */
  	public int findReferencePosition(int offset, boolean danglingElse, boolean matchBrace, boolean matchParen, boolean matchCase) {
  		fIndent= 0; // the indentation modification
  		fAlign= JavaHeuristicScanner.NOT_FOUND;
  		fPosition= offset;
  
  		// forward cases
  		// an unindentation happens sometimes if the next token is special, namely on braces, parens and case labels
  		// align braces, but handle the case where we align with the method declaration start instead of
  		// the opening brace.
  		if (matchBrace) {
  			if (skipScope(Symbols.TokenLBRACE, Symbols.TokenRBRACE)) {
  				try {
  					// align with the opening brace that is on a line by its own
  					int lineOffset= fDocument.getLineOffset(fLine);
  					if (lineOffset <= fPosition && fDocument.get(lineOffset, fPosition - lineOffset).trim().length() == 0)
  						return fPosition;
  				} catch (BadLocationException e) {
  					// concurrent modification - walk default path
  				}
  				// if the opening brace is not on the start of the line, skip to the start
  				int pos= skipToStatementStart(true, true);
  				fIndent= 0; // indent is aligned with reference position
  				return pos;
  			} else {
  				// if we can't find the matching brace, the heuristic is to unindent
  				// by one against the normal position
  				int pos= findReferencePosition(offset, danglingElse, false, matchParen, matchCase);
  				fIndent--;
  				return pos;
  			}
  		}
  
  		// align parenthesis'
  		if (matchParen) {
  			if (skipScope(Symbols.TokenLPAREN, Symbols.TokenRPAREN))
  				return fPosition;
  			else {
  				// if we can't find the matching paren, the heuristic is to unindent
  				// by one against the normal position
  				int pos= findReferencePosition(offset, danglingElse, matchBrace, false, matchCase);
  				fIndent--;
  				return pos;
  			}
  		}
  
  		// the only reliable way to get case labels aligned (due to many different styles of using braces in a block)
  		// is to go for another case statement, or the scope opening brace
  		if (matchCase) {
  			return matchCaseAlignment();
  		}
  
  		nextToken();
  		switch (fToken) {
  			case Symbols.TokenGREATERTHAN:
  			case Symbols.TokenRBRACKET:
  			case Symbols.TokenRBRACE:
  				// skip the block and fall through
  				// if we can't complete the scope, reset the scan position
  				int pos= fPosition;
  				if (!skipScope())
  					fPosition= pos;
  			//$FALL-THROUGH$
  			case Symbols.TokenSEMICOLON:
  				// this is the 90% case: after a statement block
  				// the end of the previous statement / block previous.end
  				// search to the end of the statement / block before the previous; the token just after that is previous.start
  				return skipToStatementStart(danglingElse, false);
  
  			// scope introduction: special treat who special is
  			case Symbols.TokenLPAREN:
  			case Symbols.TokenLBRACE:
  			case Symbols.TokenLBRACKET:
  				return handleScopeIntroduction(offset + 1);
  
  			case Symbols.TokenEOF:
  				// trap when hitting start of document
  				return JavaHeuristicScanner.NOT_FOUND;
  
  			case Symbols.TokenEQUAL:
  				// indent assignments
  				fIndent= fPrefs.prefAssignmentIndent;
  				return fPosition;
  
  			case Symbols.TokenCOLON:
  				// TODO handle ternary deep indentation
  				fIndent= fPrefs.prefCaseBlockIndent;
  				return fPosition;
  
  			case Symbols.TokenQUESTIONMARK:
  				if (fPrefs.prefTernaryDeepAlign) {
  					setFirstElementAlignment(fPosition, offset + 1);
  					return fPosition;
  				} else {
  					fIndent= fPrefs.prefTernaryIndent;
  					return fPosition;
  				}
  
  			// indentation for blockless introducers:
  			case Symbols.TokenDO:
  			case Symbols.TokenWHILE:
  			case Symbols.TokenELSE:
  				fIndent= fPrefs.prefSimpleIndent;
  				return fPosition;
  
  			case Symbols.TokenTRY:
  				return skipToStatementStart(danglingElse, false);
  			case Symbols.TokenRPAREN:
  				int line= fLine;
  				if (skipScope(Symbols.TokenLPAREN, Symbols.TokenRPAREN)) {
  					int scope= fPosition;
  					nextToken();
  					if (fToken == Symbols.TokenIF || fToken == Symbols.TokenWHILE || fToken == Symbols.TokenFOR) {
  						fIndent= fPrefs.prefSimpleIndent;
  						return fPosition;
  					}
  					fPosition= scope;
  					if (looksLikeMethodDecl()) {
  						return skipToStatementStart(danglingElse, false);
  					}
  					if (fToken == Symbols.TokenCATCH) {
  						return skipToStatementStart(danglingElse, false);
  					}
  					fPosition= scope;
  					if (looksLikeAnonymousTypeDecl()) {
  						return skipToStatementStart(danglingElse, false);
  					}
  				}
  				// restore
  				fPosition= offset;
  				fLine= line;
  				// else: fall through to default
  				//$FALL-THROUGH$
  			case Symbols.TokenCOMMA:
  				// inside a list of some type
  				// easy if there is already a list item before with its own indentation - we just align
  				// if not: take the start of the list ( LPAREN, LBRACE, LBRACKET ) and either align or
  				// indent by list-indent
  			default:
  				// inside whatever we don't know about: similar to the list case:
  				// if we are inside a continued expression, then either align with a previous line that has indentation
  				// or indent from the expression start line (either a scope introducer or the start of the expr).
  				return skipToPreviousListItemOrListStart();
  
  		}
  	}
  
  	/**
  	 * Skips to the start of a statement that ends at the current position.
  	 *
  	 * @param danglingElse whether to indent aligned with the last <code>if</code>
  	 * @param isInBlock whether the current position is inside a block, which limits the search scope to the next scope introducer
  	 * @return the reference offset of the start of the statement
  	 */
  	private int skipToStatementStart(boolean danglingElse, boolean isInBlock) {
  		final int NOTHING= 0;
  		final int READ_PARENS= 1;
  		final int READ_IDENT= 2;
  		int mayBeMethodBody= NOTHING;
  		boolean isTypeBody= false;
  		while (true) {
  			nextToken();
  
  			if (isInBlock) {
  				switch (fToken) {
  					// exit on all block introducers
  					case Symbols.TokenIF:
  					case Symbols.TokenELSE:
  					case Symbols.TokenCATCH:
  					case Symbols.TokenDO:
  					case Symbols.TokenWHILE:
  					case Symbols.TokenFINALLY:
  					case Symbols.TokenFOR:
  					case Symbols.TokenTRY:
  					case Symbols.TokenCOLON:
  						return fPosition;
  
  					case Symbols.TokenSTATIC:
  						mayBeMethodBody= READ_IDENT; // treat static blocks like methods
  						break;
  
  					case Symbols.TokenSYNCHRONIZED:
  						// if inside a method declaration, use body indentation
  						// else use block indentation.
  						if (mayBeMethodBody != READ_IDENT)
  							return fPosition;
  						break;
  
  					case Symbols.TokenCLASS:
  					case Symbols.TokenINTERFACE:
  					case Symbols.TokenENUM:
  						isTypeBody= true;
  						break;
  
  					case Symbols.TokenSWITCH:
  						fIndent= fPrefs.prefCaseIndent;
  						return fPosition;
  				}
  			}
  
  			switch (fToken) {
  				// scope introduction through: LPAREN, LBRACE, LBRACKET
  				// search stop on SEMICOLON, RBRACE, COLON, EOF
  				// -> the next token is the start of the statement (i.e. previousPos when backward scanning)
  				case Symbols.TokenLPAREN:
  				case Symbols.TokenLBRACE:
  				case Symbols.TokenLBRACKET:
  				case Symbols.TokenSEMICOLON:
  				case Symbols.TokenEOF:
  					if (isInBlock)
  						fIndent= getBlockIndent(mayBeMethodBody == READ_IDENT, isTypeBody);
  					// else: fIndent set by previous calls
  					return fPreviousPos;
  
  				case Symbols.TokenCOLON:
  					int pos= fPreviousPos;
  					if (!isConditional())
  						return pos;
  					break;
  
  				case Symbols.TokenRBRACE:
  					// RBRACE is a little tricky: it can be the end of an array definition, but
  					// usually it is the end of a previous block
  					pos= fPreviousPos; // store state
  					if (skipScope() && looksLikeArrayInitializerIntro()) {
  						continue; // it's an array
  					} else {
  						if (isInBlock)
  							fIndent= getBlockIndent(mayBeMethodBody == READ_IDENT, isTypeBody);
  						return pos; // it's not - do as with all the above
  					}
  
  				// scopes: skip them
  				case Symbols.TokenRPAREN:
  					if (isInBlock)
  						mayBeMethodBody= READ_PARENS;
  					//$FALL-THROUGH$
  				case Symbols.TokenRBRACKET:
  				case Symbols.TokenGREATERTHAN:
  					pos= fPreviousPos;
  					if (skipScope())
  						break;
  					else
  						return pos;
  
  				// IF / ELSE: align the position after the conditional block with the if
  				// so we are ready for an else, except if danglingElse is false
  				// in order for this to work, we must skip an else to its if
  				case Symbols.TokenIF:
  					if (danglingElse)
  						return fPosition;
  					else
  						break;
  				case Symbols.TokenELSE:
  					// skip behind the next if, as we have that one covered
  					pos= fPosition;
  					if (skipNextIF())
  						break;
  					else
  						return pos;
  
  				case Symbols.TokenDO:
  					// align the WHILE position with its do
  					return fPosition;
  
  				case Symbols.TokenWHILE:
  					// this one is tricky: while can be the start of a while loop
  					// or the end of a do - while
  					pos= fPosition;
  					if (hasMatchingDo()) {
  						// continue searching from the DO on
  						break;
  					} else {
  						// continue searching from the WHILE on
  						fPosition= pos;
  						break;
  					}
  				case Symbols.TokenIDENT:
  					if (mayBeMethodBody == READ_PARENS)
  						mayBeMethodBody= READ_IDENT;
  					break;
  
  				default:
  					// keep searching
  
  			}
  
  		}
  	}
  
  	private int getBlockIndent(boolean isMethodBody, boolean isTypeBody) {
  		if (isTypeBody)
  			return fPrefs.prefTypeIndent + (fPrefs.prefIndentBracesForTypes ? 1 : 0);
  		else if (isMethodBody)
  			return fPrefs.prefMethodBodyIndent + (fPrefs.prefIndentBracesForMethods ? 1 : 0);
  		else
  			return fIndent;
  	}
  
  	/**
  	 * Returns true if the colon at the current position is part of a conditional
  	 * (ternary) expression, false otherwise.
  	 *
  	 * @return true if the colon at the current position is part of a conditional
  	 */
  	private boolean isConditional() {
  		while (true) {
  			nextToken();
  			switch (fToken) {
  
  				// search for case labels, which consist of (possibly qualified) identifiers or numbers
  				case Symbols.TokenIDENT:
  				case Symbols.TokenOTHER: // dots for qualified constants
  					continue;
  				case Symbols.TokenCASE:
  					return false;
  
  				default:
  					return true;
  			}
  		}
  	}
  
  	/**
  	 * Returns as a reference any previous <code>switch</code> labels (<code>case</code>
  	 * or <code>default</code>) or the offset of the brace that scopes the switch
  	 * statement. Sets <code>fIndent</code> to <code>prefCaseIndent</code> upon
  	 * a match.
  	 *
  	 * @return the reference offset for a <code>switch</code> label
  	 */
  	private int matchCaseAlignment() {
  		while (true) {
  			nextToken();
  			switch (fToken) {
  				// invalid cases: another case label or an LBRACE must come before a case
  				// -> bail out with the current position
  				case Symbols.TokenLPAREN:
  				case Symbols.TokenLBRACKET:
  				case Symbols.TokenEOF:
  					return fPosition;
  				case Symbols.TokenLBRACE:
  					// opening brace of switch statement
  					fIndent= fPrefs.prefCaseIndent;
  					return fPosition;
  				case Symbols.TokenCASE:
  				case Symbols.TokenDEFAULT:
  					// align with previous label
  					fIndent= 0;
  					return fPosition;
  
  				// scopes: skip them
  				case Symbols.TokenRPAREN:
  				case Symbols.TokenRBRACKET:
  				case Symbols.TokenRBRACE:
  				case Symbols.TokenGREATERTHAN:
  					skipScope();
  					break;
  
  				default:
  					// keep searching
  					continue;
  
  			}
  		}
  	}
  
  	/**
  	 * Returns the reference position for a list element. The algorithm
  	 * tries to match any previous indentation on the same list. If there is none,
  	 * the reference position returned is determined depending on the type of list:
  	 * The indentation will either match the list scope introducer (e.g. for
  	 * method declarations), so called deep indents, or simply increase the
  	 * indentation by a number of standard indents. See also {@link #handleScopeIntroduction(int)}.
  	 *
  	 * @return the reference position for a list item: either a previous list item
  	 * that has its own indentation, or the list introduction start.
  	 */
  	private int skipToPreviousListItemOrListStart() {
  		int startLine= fLine;
  		int startPosition= fPosition;
  		while (true) {
  			nextToken();
  
  			// if any line item comes with its own indentation, adapt to it
  			if (fLine < startLine) {
  				try {
  					int lineOffset= fDocument.getLineOffset(startLine);
  					int bound= Math.min(fDocument.getLength(), startPosition + 1);
  					fAlign= fScanner.findNonWhitespaceForwardInAnyPartition(lineOffset, bound);
  				} catch (BadLocationException e) {
  					// ignore and return just the position
  				}
  				return startPosition;
  			}
  
  			switch (fToken) {
  				// scopes: skip them
  				case Symbols.TokenRPAREN:
  				case Symbols.TokenRBRACKET:
  				case Symbols.TokenRBRACE:
  				case Symbols.TokenGREATERTHAN:
  					skipScope();
  					break;
  
  				// scope introduction: special treat who special is
  				case Symbols.TokenLPAREN:
  				case Symbols.TokenLBRACE:
  				case Symbols.TokenLBRACKET:
  					return handleScopeIntroduction(startPosition + 1);
  
  				case Symbols.TokenSEMICOLON:
  					return fPosition;
  				case Symbols.TokenQUESTIONMARK:
  					if (fPrefs.prefTernaryDeepAlign) {
  						setFirstElementAlignment(fPosition - 1, fPosition + 1);
  						return fPosition;
  					} else {
  						fIndent= fPrefs.prefTernaryIndent;
  						return fPosition;
  					}
  				case Symbols.TokenEOF:
  					return 0;
  
  			}
  		}
  	}
  
  	/**
  	 * Skips a scope and positions the cursor (<code>fPosition</code>) on the
  	 * token that opens the scope. Returns <code>true</code> if a matching peer
  	 * could be found, <code>false</code> otherwise. The current token when calling
  	 * must be one out of <code>Symbols.TokenRPAREN</code>, <code>Symbols.TokenRBRACE</code>,
  	 * and <code>Symbols.TokenRBRACKET</code>.
  	 *
  	 * @return <code>true</code> if a matching peer was found, <code>false</code> otherwise
  	 */
  	private boolean skipScope() {
  		switch (fToken) {
  			case Symbols.TokenRPAREN:
  				return skipScope(Symbols.TokenLPAREN, Symbols.TokenRPAREN);
  			case Symbols.TokenRBRACKET:
  				return skipScope(Symbols.TokenLBRACKET, Symbols.TokenRBRACKET);
  			case Symbols.TokenRBRACE:
  				return skipScope(Symbols.TokenLBRACE, Symbols.TokenRBRACE);
  			case Symbols.TokenGREATERTHAN:
  				if (!fPrefs.prefHasGenerics)
  					return false;
  				int storedPosition= fPosition;
  				int storedToken= fToken;
  				nextToken();
  				switch (fToken) {
  					case Symbols.TokenIDENT:
  						if (!JavaHeuristicScanner.isGenericStarter(getTokenContent()))
  							break;
  						//$FALL-THROUGH$
  					case Symbols.TokenQUESTIONMARK:
  					case Symbols.TokenGREATERTHAN:
  						if (skipScope(Symbols.TokenLESSTHAN, Symbols.TokenGREATERTHAN))
  							return true;
  				}
  				// <> are harder to detect - restore the position if we fail
  				fPosition= storedPosition;
  				fToken= storedToken;
  				return false;
  
  			default:
  				Assert.isTrue(false);
  				return false;
  		}
  	}
  
  	/**
  	 * Returns the contents of the current token.
  	 *
  	 * @return the contents of the current token
  	 * 
  	 */
  	private CharSequence getTokenContent() {
  		return new DocumentCharacterIterator(fDocument, fPosition, fPreviousPos);
  	}
  
  	/**
  	 * Handles the introduction of a new scope. The current token must be one out
  	 * of <code>Symbols.TokenLPAREN</code>, <code>Symbols.TokenLBRACE</code>,
  	 * and <code>Symbols.TokenLBRACKET</code>. Returns as the reference position
  	 * either the token introducing the scope or - if available - the first
  	 * java token after that.
  	 *
  	 * <p>Depending on the type of scope introduction, the indentation will align
  	 * (deep indenting) with the reference position (<code>fAlign</code> will be
  	 * set to the reference position) or <code>fIndent</code> will be set to
  	 * the number of indentation units.
  	 * </p>
  	 *
  	 * @param bound the bound for the search for the first token after the scope
  	 * introduction.
  	 * @return the indent
  	 */
  	private int handleScopeIntroduction(int bound) {
  		switch (fToken) {
  			// scope introduction: special treat who special is
  			case Symbols.TokenLPAREN:
  				int pos= fPosition; // store
  
  				// special: method declaration deep indentation
  				if (looksLikeMethodDecl()) {
  					if (fPrefs.prefMethodDeclDeepIndent)
  						return setFirstElementAlignment(pos, bound);
  					else {
  						fIndent= fPrefs.prefMethodDeclIndent;
  						return pos;
  					}
  				} else {
  					fPosition= pos;
  					if (looksLikeMethodCall()) {
  						if (fPrefs.prefMethodCallDeepIndent)
  							return setFirstElementAlignment(pos, bound);
  						else {
  							fIndent= fPrefs.prefMethodCallIndent;
  							return pos;
  						}
  					} else if (fPrefs.prefParenthesisDeepIndent)
  						return setFirstElementAlignment(pos, bound);
  				}
  
  				// normal: return the parenthesis as reference
  				fIndent= fPrefs.prefParenthesisIndent;
  				return pos;
  
  			case Symbols.TokenLBRACE:
  				pos= fPosition; // store
  
  				// special: array initializer
  				if (looksLikeArrayInitializerIntro())
  					if (fPrefs.prefArrayDeepIndent)
  						return setFirstElementAlignment(pos, bound);
  					else
  						fIndent= fPrefs.prefArrayIndent;
  				else
  					fIndent= fPrefs.prefBlockIndent;
  
  				// normal: skip to the statement start before the scope introducer
  				// opening braces are often on differently ending indents than e.g. a method definition
  				if (looksLikeArrayInitializerIntro() && !fPrefs.prefIndentBracesForArrays
  						|| !fPrefs.prefIndentBracesForBlocks) {
  					fPosition= pos; // restore
  					return skipToStatementStart(true, true); // set to true to match the first if
  				} else {
  					return pos;
  				}
  
  			case Symbols.TokenLBRACKET:
  				pos= fPosition; // store
  
  				// special: method declaration deep indentation
  				if (fPrefs.prefArrayDimensionsDeepIndent) {
  					return setFirstElementAlignment(pos, bound);
  				}
  
  				// normal: return the bracket as reference
  				fIndent= fPrefs.prefBracketIndent;
  				return pos; // restore
  
  			default:
  				Assert.isTrue(false);
  				return -1; // dummy
  		}
  	}
  
  	/**
  	 * Sets the deep indent offset (<code>fAlign</code>) to either the offset
  	 * right after <code>scopeIntroducerOffset</code> or - if available - the
  	 * first Java token after <code>scopeIntroducerOffset</code>, but before
  	 * <code>bound</code>.
  	 *
  	 * @param scopeIntroducerOffset the offset of the scope introducer
  	 * @param bound the bound for the search for another element
  	 * @return the reference position
  	 */
  	private int setFirstElementAlignment(int scopeIntroducerOffset, int bound) {
  		int firstPossible= scopeIntroducerOffset + 1; // align with the first position after the scope intro
  		fAlign= fScanner.findNonWhitespaceForwardInAnyPartition(firstPossible, bound);
  		if (fAlign == JavaHeuristicScanner.NOT_FOUND)
  			fAlign= firstPossible;
  		return fAlign;
  	}
  
  
  	/**
  	 * Returns <code>true</code> if the next token received after calling
  	 * <code>nextToken</code> is either an equal sign or an array designator ('[]').
  	 *
  	 * @return <code>true</code> if the next elements look like the start of an array definition
  	 */
  	private boolean looksLikeArrayInitializerIntro() {
  		nextToken();
  		if (fToken == Symbols.TokenEQUAL || skipBrackets()) {
  			return true;
  		}
  		return false;
  	}
  
  	/**
  	 * Skips over the next <code>if</code> keyword. The current token when calling
  	 * this method must be an <code>else</code> keyword. Returns <code>true</code>
  	 * if a matching <code>if</code> could be found, <code>false</code> otherwise.
  	 * The cursor (<code>fPosition</code>) is set to the offset of the <code>if</code>
  	 * token.
  	 *
  	 * @return <code>true</code> if a matching <code>if</code> token was found, <code>false</code> otherwise
  	 */
  	private boolean skipNextIF() {
  		Assert.isTrue(fToken == Symbols.TokenELSE);
  
  		while (true) {
  			nextToken();
  			switch (fToken) {
  				// scopes: skip them
  				case Symbols.TokenRPAREN:
  				case Symbols.TokenRBRACKET:
  				case Symbols.TokenRBRACE:
  				case Symbols.TokenGREATERTHAN:
  					skipScope();
  					break;
  
  				case Symbols.TokenIF:
  					// found it, return
  					return true;
  				case Symbols.TokenELSE:
  					// recursively skip else-if blocks
  					skipNextIF();
  					break;
  
  				// shortcut scope starts
  				case Symbols.TokenLPAREN:
  				case Symbols.TokenLBRACE:
  				case Symbols.TokenLBRACKET:
  				case Symbols.TokenEOF:
  					return false;
  				}
  		}
  	}
  
  
  	/**
  	 * while(condition); is ambiguous when parsed backwardly, as it is a valid
  	 * statement by its own, so we have to check whether there is a matching
  	 * do. A <code>do</code> can either be separated from the while by a
  	 * block, or by a single statement, which limits our search distance.
  	 *
  	 * @return <code>true</code> if the <code>while</code> currently in
  	 *         <code>fToken</code> has a matching <code>do</code>.
  	 */
  	private boolean hasMatchingDo() {
  		Assert.isTrue(fToken == Symbols.TokenWHILE);
  		nextToken();
  		switch (fToken) {
  			case Symbols.TokenRBRACE:
  				skipScope(); // and fall thru
  				//$FALL-THROUGH$
  			case Symbols.TokenSEMICOLON:
  				skipToStatementStart(false, false);
  				return fToken == Symbols.TokenDO;
  		}
  		return false;
  	}
  
  	/**
  	 * Skips brackets if the current token is a RBRACKET. There can be nothing
  	 * but whitespace in between, this is only to be used for <code>[]</code> elements.
  	 *
  	 * @return <code>true</code> if a <code>[]</code> could be scanned, the
  	 *         current token is left at the LBRACKET.
  	 */
  	private boolean skipBrackets() {
  		if (fToken == Symbols.TokenRBRACKET) {
  			nextToken();
  			if (fToken == Symbols.TokenLBRACKET) {
  				return true;
  			}
  		}
  		return false;
  	}
  
  	/**
  	 * Reads the next token in backward direction from the heuristic scanner
  	 * and sets the fields <code>fToken, fPreviousPosition</code> and <code>fPosition</code>
  	 * accordingly.
  	 */
  	private void nextToken() {
  		nextToken(fPosition);
  	}
  
  	/**
  	 * Reads the next token in backward direction of <code>start</code> from
  	 * the heuristic scanner and sets the fields <code>fToken, fPreviousPosition</code>
  	 * and <code>fPosition</code> accordingly.
  	 *
  	 * @param start the start offset from which to scan backwards
  	 */
  	private void nextToken(int start) {
  		fToken= fScanner.previousToken(start - 1, JavaHeuristicScanner.UNBOUND);
  		fPreviousPos= start;
  		fPosition= fScanner.getPosition() + 1;
  		try {
  			fLine= fDocument.getLineOfOffset(fPosition);
  		} catch (BadLocationException e) {
  			fLine= -1;
  		}
  	}
  
  	/**
  	 * Returns <code>true</code> if the current tokens look like a method
  	 * declaration header (i.e. only the return type and method name). The
  	 * heuristic calls <code>nextToken</code> and expects an identifier
  	 * (method name) and a type declaration (an identifier with optional
  	 * brackets) which also covers the visibility modifier of constructors; it
  	 * does not recognize package visible constructors.
  	 *
  	 * @return <code>true</code> if the current position looks like a method
  	 *         declaration header.
  	 */
  	private boolean looksLikeMethodDecl() {
  		/*
  		 * TODO This heuristic does not recognize package private constructors
  		 * since those do have neither type nor visibility keywords.
  		 * One option would be to go over the parameter list, but that might
  		 * be empty as well, or not typed in yet - hard to do without an AST...
  		 */
  
  		nextToken();
  		if (fToken == Symbols.TokenIDENT) { // method name
  			do nextToken();
  			while (skipBrackets()); // optional brackets for array valued return types
  
  			return fToken == Symbols.TokenIDENT; // return type name
  
  		}
  		return false;
  	}
  
  	/**
  	 * Returns <code>true</code> if the current tokens look like an anonymous type declaration
  	 * header (i.e. a type name (potentially qualified) and a new keyword). The heuristic calls
  	 * <code>nextToken</code> and expects a possibly qualified identifier (type name) and a new
  	 * keyword
  	 * 
  	 * @return <code>true</code> if the current position looks like a anonymous type declaration
  	 *         header.
  	 */
  	private boolean looksLikeAnonymousTypeDecl() {
  		
  		nextToken();
  		if (fToken == Symbols.TokenIDENT) { // type name
  			nextToken();
  			while (fToken == Symbols.TokenOTHER) { // dot of qualification
  				nextToken();
  				if (fToken != Symbols.TokenIDENT) // qualificating name
  					return false;
  				nextToken();
  			}
  			return fToken == Symbols.TokenNEW;
  		}
  		return false;
  	}
  
  	/**
  	 * Returns <code>true</code> if the current tokens look like a method
  	 * call header (i.e. an identifier as opposed to a keyword taking parenthesized
  	 * parameters such as <code>if</code>).
  	 * <p>The heuristic calls <code>nextToken</code> and expects an identifier
  	 * (method name).
  	 *
  	 * @return <code>true</code> if the current position looks like a method call
  	 *         header.
  	 */
  	private boolean looksLikeMethodCall() {
  		// TODO [5.0] add awareness for constructor calls with generic types: new ArrayList<String>()
  		nextToken();
  		return fToken == Symbols.TokenIDENT; // method name
  	}
  
  	/**
  	 * Scans tokens for the matching opening peer. The internal cursor
  	 * (<code>fPosition</code>) is set to the offset of the opening peer if found.
  	 *
  	 * @param openToken the opening peer token
  	 * @param closeToken the closing peer token
  	 * @return <code>true</code> if a matching token was found, <code>false</code>
  	 *         otherwise
  	 */
  	private boolean skipScope(int openToken, int closeToken) {
  
  		int depth= 1;
  
  		while (true) {
  			nextToken();
  
  			if (fToken == closeToken) {
  				depth++;
  			} else if (fToken == openToken) {
  				depth--;
  				if (depth == 0)
  					return true;
  			} else if (fToken == Symbols.TokenEOF) {
  					return false;
  			}
  		}
  	}
  }
  