/*******************************************************************************
* Copyright (c) 2000, 2005 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.rubypeople.rdt.internal.ui.text.comment;
import java.util.LinkedList;
import java.util.Map;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.TextUtilities;
import org.eclipse.jface.text.TypedPosition;
import org.eclipse.jface.text.formatter.ContextBasedFormattingStrategy;
import org.eclipse.jface.text.formatter.FormattingContextProperties;
import org.eclipse.jface.text.formatter.IFormattingContext;
import org.eclipse.text.edits.MalformedTreeException;
import org.eclipse.text.edits.TextEdit;
import org.rubypeople.rdt.core.ToolFactory;
import org.rubypeople.rdt.core.formatter.DefaultCodeFormatterConstants;
import org.rubypeople.rdt.core.formatter.CodeFormatter;
import org.rubypeople.rdt.internal.ui.RubyPlugin;
import org.rubypeople.rdt.internal.ui.text.IRubyPartitions;
/**
* Formatting strategy for general source code comments.
*
* @since 3.0
*/
public class CommentFormattingStrategy extends ContextBasedFormattingStrategy {
/** Documents to be formatted by this strategy */
private final LinkedList fDocuments= new LinkedList();
/** Partitions to be formatted by this strategy */
private final LinkedList fPartitions= new LinkedList();
/** Last formatted document's hash-code. */
private int fLastDocumentHash;
/** Last formatted document header's hash-code. */
private int fLastHeaderHash;
/** End of the first class or interface token in the last document. */
private int fLastMainTokenEnd= -1;
/** End of the header in the last document. */
private int fLastDocumentsHeaderEnd;
/*
* @see org.eclipse.jface.text.formatter.IFormattingStrategyExtension#format()
*/
public void format() {
super.format();
final IDocument document= (IDocument) fDocuments.removeFirst();
final TypedPosition position= (TypedPosition)fPartitions.removeFirst();
if (document == null || position == null)
return;
Map preferences= getPreferences();
final boolean isFormattingHeader= Boolean.toString(true).equals(preferences.get(DefaultCodeFormatterConstants.FORMATTER_COMMENT_FORMAT_HEADER));
int documentsHeaderEnd= computeHeaderEnd(document);
if (isFormattingHeader || position.offset >= documentsHeaderEnd) {
TextEdit edit= null;
try {
// compute offset in document of region passed to the formatter
int sourceOffset= document.getLineOffset(document.getLineOfOffset(position.getOffset()));
// format region
int partitionOffset= position.getOffset() - sourceOffset;
int sourceLength= partitionOffset + position.getLength();
String source= document.get(sourceOffset, sourceLength);
CodeFormatter commentFormatter= ToolFactory.createCodeFormatter(preferences);
int indentationLevel= inferIndentationLevel(source.substring(0, partitionOffset), getTabSize(preferences));
edit= commentFormatter.format(getKindForPartitionType(position.getType()), source, partitionOffset, position.getLength(), indentationLevel, TextUtilities.getDefaultLineDelimiter(document));
// move edit offset to match document
if (edit != null)
edit.moveTree(sourceOffset);
} catch (BadLocationException x) {
RubyPlugin.log(x);
}
try {
if (edit != null)
edit.apply(document);
} catch (MalformedTreeException x) {
RubyPlugin.log(x);
} catch (BadLocationException x) {
RubyPlugin.log(x);
}
}
}
/*
* @see org.eclipse.jface.text.formatter.IFormattingStrategyExtension#formatterStarts(org.eclipse.jface.text.formatter.IFormattingContext)
*/
public void formatterStarts(IFormattingContext context) {
super.formatterStarts(context);
fPartitions.addLast(context.getProperty(FormattingContextProperties.CONTEXT_PARTITION));
fDocuments.addLast(context.getProperty(FormattingContextProperties.CONTEXT_MEDIUM));
}
/*
* @see org.eclipse.jface.text.formatter.IFormattingStrategyExtension#formatterStops()
*/
public void formatterStops() {
fPartitions.clear();
fDocuments.clear();
super.formatterStops();
}
/**
* Map from {@link IRubyPartitions}comment partition types to
* {@link CodeFormatter}code snippet kinds.
*
* @param type the partition type
* @return the code snippet kind
* @since 3.1
*/
private static int getKindForPartitionType(String type) {
if (IRubyPartitions.RUBY_SINGLE_LINE_COMMENT.equals(type))
return CodeFormatter.K_SINGLE_LINE_COMMENT;
if (IRubyPartitions.RUBY_MULTI_LINE_COMMENT.equals(type))
return CodeFormatter.K_MULTI_LINE_COMMENT;
return CodeFormatter.K_UNKNOWN;
}
/**
* Infer the indentation level based on the given reference indentation
* and tab size.
*
* @param reference the reference indentation
* @param tabSize the tab size
* @return the inferred indentation level
* @since 3.1
*/
private int inferIndentationLevel(String reference, int tabSize) {
StringBuffer expanded= expandTabs(reference, tabSize);
int referenceWidth= expanded.length();
if (tabSize == 0)
return referenceWidth;
int spaceWidth= 1;
int level= referenceWidth / (tabSize * spaceWidth);
if (referenceWidth % (tabSize * spaceWidth) > 0)
level++;
return level;
}
/**
* Expands the given string's tabs according to the given tab size.
*
* @param string the string
* @param tabSize the tab size
* @return the expanded string
* @since 3.1
*/
private static StringBuffer expandTabs(String string, int tabSize) {
StringBuffer expanded= new StringBuffer();
for (int i= 0, n= string.length(), chars= 0; i < n; i++) {
char ch= string.charAt(i);
if (ch == '\t') {
for (; chars < tabSize; chars++)
expanded.append(' ');
chars= 0;
} else {
expanded.append(ch);
chars++;
if (chars >= tabSize)
chars= 0;
}
}
return expanded;
}
/**
* Returns the value of {@link DefaultCodeFormatterConstants#FORMATTER_TAB_SIZE}
* from the given preferences.
*
* @param preferences the preferences
* @return the value of {@link DefaultCodeFormatterConstants#FORMATTER_TAB_SIZE}
* from the given preferences
* @since 3.1
*/
private static int getTabSize(Map preferences) {
if (preferences.containsKey(DefaultCodeFormatterConstants.FORMATTER_TAB_SIZE))
try {
return Integer.parseInt((String) preferences.get(DefaultCodeFormatterConstants.FORMATTER_TAB_SIZE));
} catch (NumberFormatException e) {
// use default
}
return 4;
}
/**
* Returns the end offset for the document's header.
*
* @param document the document
* @return the header's end offset
*/
private int computeHeaderEnd(IDocument document) {
if (document == null)
return -1;
try {
if (fLastMainTokenEnd >= 0 && document.hashCode() == fLastDocumentHash && fLastMainTokenEnd < document.getLength() && document.get(0, fLastMainTokenEnd).hashCode() == fLastHeaderHash)
return fLastDocumentsHeaderEnd;
} catch (BadLocationException e) {
// should not happen -> recompute
}
// FIXME Search for end of initial comment. If we hit code, then give up
return -1;
}
}