plugins/org.eclipse.dltk.sh.ui/src/org/eclipse/dltk/sh/internal/ui/text/DocumentAndCommandScanner.java

/*******************************************************************************
 * Copyright (c) 2009 Red Hat Inc. and others.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 * 
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     Alexander Kurtakov - initial API and implementation
 *******************************************************************************/
package org.eclipse.dltk.sh.internal.ui.text;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.DocumentCommand;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.rules.RuleBasedScanner;

/**
 * This scanner extends the normal rule based scanner by adding the ability to
 * read DocumentCommands as well as IDocuments. This ability is toggled on or
 * off depending on whether setRange(document,offset,length) (off) or
 * setRange(document,documentCommand,offset,length) (on) was called.
 *
 * @author Doug Satchwell
 * @version $Id: DocumentAndCommandScanner.java,v 1.2 2008/12/02 21:59:55
 *          akurtakov Exp $
 */
public class DocumentAndCommandScanner extends RuleBasedScanner {
	private DocumentCommand fDocumentCommand;

	@Override
	public int read() {
		try {
			if (fOffset < fRangeEnd) {
				try {
					return fDocument.getChar(fOffset);
				} catch (BadLocationException e) {
				}
			}
			if ((fDocumentCommand != null) && (fOffset < (fRangeEnd + fDocumentCommand.text.length()))) {
				return fDocumentCommand.text.charAt(((fRangeEnd + fDocumentCommand.text.length()) - fOffset) - 1);
			}
			return EOF;
		} finally {
			++fOffset;
		}
	}

	/**
	 * Set this to use as a normal in conjunction with DocumentCommand's
	 */
	public void setRange(IDocument document, DocumentCommand documentCommand, int offset, int length) {
		setRange(document, offset, length);
		fDocumentCommand = documentCommand;
	}

	/**
	 * Set this to use as a normal RuleBasedScanner
	 */
	@Override
	public void setRange(IDocument document, int offset, int length) {
		super.setRange(document, offset, length);
		fDocumentCommand = null;
	}
}