/*******************************************************************************
* Copyright (c) 2009 University of Edinburgh.
* All rights reserved. This program and the accompanying materials are made
* available under the terms of the BSD Licence, which accompanies this feature
* and can be downloaded from http://groups.inf.ed.ac.uk/pepa/update/licence.txt
******************************************************************************/
package uk.ac.ed.inf.biopepa.ui.editors;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.DocumentEvent;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITypedRegion;
import org.eclipse.jface.text.Region;
import org.eclipse.jface.text.TextAttribute;
import org.eclipse.jface.text.TextPresentation;
import org.eclipse.jface.text.presentation.IPresentationDamager;
import org.eclipse.jface.text.presentation.IPresentationRepairer;
import org.eclipse.jface.text.rules.IToken;
import org.eclipse.jface.text.rules.ITokenScanner;
import org.eclipse.jface.text.rules.Token;
import org.eclipse.core.runtime.Assert;
import org.eclipse.swt.custom.StyleRange;
public class NonRuleBasedDamagerRepairer implements IPresentationDamager,
IPresentationRepairer {
/** The document this object works on */
protected IDocument fDocument;
/**
* The default text attribute if non is returned as data by the current
* token
*/
protected TextAttribute fDefaultTextAttribute;
protected ITokenScanner scanner;
/**
* Constructor for NonRuleBasedDamagerRepairer.
*/
public NonRuleBasedDamagerRepairer(ITokenScanner scanner,
TextAttribute defaultTextAttribute) {
Assert.isNotNull(defaultTextAttribute);
Assert.isNotNull(scanner);
this.scanner = scanner;
fDefaultTextAttribute = defaultTextAttribute;
}
/**
* @see IPresentationRepairer#setDocument(IDocument)
*/
public void setDocument(IDocument document) {
fDocument = document;
}
/**
* Returns the end offset of the line that contains the specified offset or
* if the offset is inside a line delimiter, the end offset of the next
* line.
*
* @param offset
* the offset whose line end offset must be computed
* @return the line end offset for the given offset
* @exception BadLocationException
* if offset is invalid in the current document
*/
protected int endOfLineOf(int offset) throws BadLocationException {
IRegion info = fDocument.getLineInformationOfOffset(offset);
if (offset <= info.getOffset() + info.getLength())
return info.getOffset() + info.getLength();
int line = fDocument.getLineOfOffset(offset);
try {
info = fDocument.getLineInformation(line + 1);
return info.getOffset() + info.getLength();
} catch (BadLocationException x) {
return fDocument.getLength();
}
}
/**
* @see IPresentationDamager#getDamageRegion(ITypedRegion, DocumentEvent,
* boolean)
*/
public IRegion getDamageRegion(ITypedRegion partition, DocumentEvent event,
boolean documentPartitioningChanged) {
if (!documentPartitioningChanged) {
try {
IRegion info = fDocument.getLineInformationOfOffset(event
.getOffset());
int start = Math.max(partition.getOffset(), info.getOffset());
int end = event.getOffset()
+ (event.getText() == null ? event.getLength() : event
.getText().length());
if (info.getOffset() <= end
&& end <= info.getOffset() + info.getLength()) {
// optimize the case of the same line
end = info.getOffset() + info.getLength();
} else
end = endOfLineOf(end);
end = Math.min(partition.getOffset() + partition.getLength(),
end);
return new Region(start, end - start);
} catch (BadLocationException x) {
}
}
return partition;
}
/**
* @see IPresentationRepairer#createPresentation(TextPresentation,
* ITypedRegion)
*/
public void createPresentation(TextPresentation presentation,
ITypedRegion region) {
// addRange(presentation, region.getOffset(), region.getLength(),
// fDefaultTextAttribute);
int lastStart = region.getOffset();
int length = 0;
boolean firstToken = true;
IToken lastToken = Token.UNDEFINED;
TextAttribute lastAttribute = getTokenTextAttribute(lastToken);
scanner.setRange(fDocument, lastStart, region.getLength());
while (true) {
IToken token = scanner.nextToken();
if (token.isEOF())
break;
TextAttribute attribute = getTokenTextAttribute(token);
if (lastAttribute != null && lastAttribute.equals(attribute)) {
length += scanner.getTokenLength();
firstToken = false;
} else {
if (!firstToken)
addRange(presentation, lastStart, length, lastAttribute);
firstToken = false;
lastToken = token;
lastAttribute = attribute;
lastStart = scanner.getTokenOffset();
length = scanner.getTokenLength();
}
}
addRange(presentation, lastStart, length, lastAttribute);
}
protected TextAttribute getTokenTextAttribute(IToken token) {
Object data = token.getData();
if (data instanceof TextAttribute)
return (TextAttribute) data;
return fDefaultTextAttribute;
}
/**
* Adds style information to the given text presentation.
*
* @param presentation
* the text presentation to be extended
* @param offset
* the offset of the range to be styled
* @param length
* the length of the range to be styled
* @param attr
* the attribute describing the style of the range to be styled
*/
protected void addRange(TextPresentation presentation, int offset,
int length, TextAttribute attr) {
if (attr != null)
presentation.addStyleRange(new StyleRange(offset, length, attr
.getForeground(), attr.getBackground(), attr.getStyle()));
}
}