/*******************************************************************************
* Copyright (c) 2000, 2009 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.jface.text.rules;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.core.runtime.Assert;
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;
/**
* A standard implementation of a syntax driven presentation damager
* and presentation repairer. It uses a token scanner to scan
* the document and to determine its damage and new text presentation.
* The tokens returned by the scanner are supposed to return text attributes
* as their data.
*
* @see ITokenScanner
* @since 2.0
*/
public class DefaultDamagerRepairer implements IPresentationDamager, IPresentationRepairer {
/** The document this object works on */
protected IDocument fDocument;
/** The scanner it uses */
protected ITokenScanner fScanner;
/** The default text attribute if non is returned as data by the current token */
protected TextAttribute fDefaultTextAttribute;
/**
* Creates a damager/repairer that uses the given scanner and returns the given default
* text attribute if the current token does not carry a text attribute.
*
* @param scanner the token scanner to be used
* @param defaultTextAttribute the text attribute to be returned if non is specified by the current token,
* may not be <code>null</code>
*
* @deprecated use DefaultDamagerRepairer(ITokenScanner) instead
*/
@Deprecated
public DefaultDamagerRepairer(ITokenScanner scanner, TextAttribute defaultTextAttribute) {
Assert.isNotNull(defaultTextAttribute);
fScanner= scanner;
fDefaultTextAttribute= defaultTextAttribute;
}
/**
* Creates a damager/repairer that uses the given scanner. The scanner may not be <code>null</code>
* and is assumed to return only token that carry text attributes.
*
* @param scanner the token scanner to be used, may not be <code>null</code>
*/
public DefaultDamagerRepairer(ITokenScanner scanner) {
Assert.isNotNull(scanner);
fScanner= scanner;
fDefaultTextAttribute= new TextAttribute(null);
}
/*
* @see IPresentationDamager#setDocument(IDocument)
* @see IPresentationRepairer#setDocument(IDocument)
*/
@Override
public void setDocument(IDocument document) {
fDocument= document;
}
//---- IPresentationDamager
/**
* 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();
}
}
/**
* {@inheritDoc}
* <p>
* This implementation damages entire lines unless clipped by the given partition.
* </p>
*
* @return the full lines containing the document changes described by the document event,
* clipped by the given partition. If there was a partitioning change then the whole
* partition is returned.
*/
@Override
public IRegion getDamageRegion(ITypedRegion partition, DocumentEvent e, boolean documentPartitioningChanged) {
if (!documentPartitioningChanged) {
try {
IRegion info= fDocument.getLineInformationOfOffset(e.getOffset());
int start= Math.max(partition.getOffset(), info.getOffset());
int end= e.getOffset() + (e.getText() == null ? e.getLength() : e.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;
}
//---- IPresentationRepairer
@Override
public void createPresentation(TextPresentation presentation, ITypedRegion region) {
if (fScanner == null) {
// will be removed if deprecated constructor will be removed
addRange(presentation, region.getOffset(), region.getLength(), fDefaultTextAttribute);
return;
}
int lastStart= region.getOffset();
int length= 0;
boolean firstToken= true;
IToken lastToken= Token.UNDEFINED;
TextAttribute lastAttribute= getTokenTextAttribute(lastToken);
fScanner.setRange(fDocument, lastStart, region.getLength());
while (true) {
IToken token= fScanner.nextToken();
if (token.isEOF())
break;
TextAttribute attribute= getTokenTextAttribute(token);
if (lastAttribute != null && lastAttribute.equals(attribute)) {
length += fScanner.getTokenLength();
firstToken= false;
} else {
if (!firstToken)
addRange(presentation, lastStart, length, lastAttribute);
firstToken= false;
lastToken= token;
lastAttribute= attribute;
lastStart= fScanner.getTokenOffset();
length= fScanner.getTokenLength();
}
}
addRange(presentation, lastStart, length, lastAttribute);
}
/**
* Returns a text attribute encoded in the given token. If the token's
* data is not <code>null</code> and a text attribute it is assumed that
* it is the encoded text attribute. It returns the default text attribute
* if there is no encoded text attribute found.
*
* @param token the token whose text attribute is to be determined
* @return the token's text attribute
*/
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) {
int style= attr.getStyle();
int fontStyle= style & (SWT.ITALIC | SWT.BOLD | SWT.NORMAL);
StyleRange styleRange= new StyleRange(offset, length, attr.getForeground(), attr.getBackground(), fontStyle);
styleRange.strikeout= (style & TextAttribute.STRIKETHROUGH) != 0;
styleRange.underline= (style & TextAttribute.UNDERLINE) != 0;
styleRange.font= attr.getFont();
presentation.addStyleRange(styleRange);
}
}
}
