org.obeonetwork.m2doc.parser.TokenIterator.java Source code

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Here is the source code for org.obeonetwork.m2doc.parser.TokenIterator.java

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/*******************************************************************************
 *  Copyright (c) 2016 Obeo. 
 *  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:
 *       Obeo - initial API and implementation
 *  
 *******************************************************************************/
package org.obeonetwork.m2doc.parser;

import java.util.Iterator;
import java.util.NoSuchElementException;

import org.apache.poi.xwpf.usermodel.BodyElementType;
import org.apache.poi.xwpf.usermodel.IBody;
import org.apache.poi.xwpf.usermodel.IBodyElement;
import org.apache.poi.xwpf.usermodel.XWPFParagraph;
import org.apache.poi.xwpf.usermodel.XWPFTable;

/**
 * {@link TokenIterator} realizes an iterator of {@link ParsingToken} over a document's body (document, table's cell, text zone, etc.).
 * 
 * @author Romain Guider
 */
public class TokenIterator implements Iterator<ParsingToken> {
    /**
     * The underlying element iterator.
     */
    private Iterator<IBodyElement> elementIterator;
    /**
     * Run or table {@link ParsingToken} iterator depending on the nature of the body.
     */
    private Iterator<ParsingToken> tokenIterator;

    /**
     * Creates a new {@link TokenIterator} instance.
     * 
     * @param inputBody
     *            the body.
     */
    public TokenIterator(IBody inputBody) {
        if (inputBody == null) {
            throw new IllegalArgumentException("Input documnet shouldn't be null");
        }
        elementIterator = inputBody.getBodyElements().iterator();
    }

    /**
     * Put the iterator in a state where it is finished or there's a token to
     * consumme in the currentIterator.
     */
    private void moveToNextToken() {
        if (tokenIterator == null || !tokenIterator.hasNext()) {
            while (elementIterator.hasNext() && (tokenIterator == null || !tokenIterator.hasNext())) {
                final IBodyElement element = elementIterator.next();
                if (element.getElementType().equals(BodyElementType.PARAGRAPH)) {
                    // create an empty run if there's no run in the paragraph.
                    // this eases the processing of documents. The processing is based on runs and a paragraph that has no run in it won't
                    // be seen by the generator and, as a consequence, won't be inserted as a static part in the result.
                    XWPFParagraph paragraph = (XWPFParagraph) element;
                    if (paragraph.getRuns().size() == 0) {
                        paragraph.createRun().setText("");
                    }
                    tokenIterator = new RunIterator(((XWPFParagraph) element).getRuns());
                } else if (element.getElementType().equals(BodyElementType.TABLE)) {
                    tokenIterator = new TableIterator((XWPFTable) element);
                } else {
                    throw new UnsupportedOperationException(
                            "Unsupported type of body element : " + element.getElementType());
                }
            }
        }
    }

    @Override
    public ParsingToken next() {
        moveToNextToken();
        if (tokenIterator != null && tokenIterator.hasNext()) {
            return tokenIterator.next();
        } else {
            throw new NoSuchElementException();
        }
    }

    @Override
    public boolean hasNext() {
        moveToNextToken();
        return tokenIterator != null && tokenIterator.hasNext();
    }

    @Override
    public void remove() {
        throw new UnsupportedOperationException();
    }
}