org.eclipse.jface.text.rules.DefaultDamagerRepairer Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of org.eclipse.jface.text Show documentation
This is org.eclipse.jface.text jar used by Scout SDK
The newest version!
/*******************************************************************************
 * 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 null
	 *
	 * @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 null
	 * and is assumed to return only token that carry text attributes.
	 *
	 * @param scanner the token scanner to be used, may not be null
	 */
	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}
	 * 
	 * This implementation damages entire lines unless clipped by the given partition.
	 * 
	 * 
	 * @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 null 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);
		}
	}
}