com.jaeksoft.searchlib.util.pdfbox.PDFBoxHighlighter.java Source code

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Here is the source code for com.jaeksoft.searchlib.util.pdfbox.PDFBoxHighlighter.java

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/**   
 * License Agreement for OpenSearchServer
 *
 * Copyright (C) 2014 Emmanuel Keller / Jaeksoft
 * 
 * http://www.open-search-server.com
 * 
 * This file is part of OpenSearchServer.
 *
 * OpenSearchServer is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 * OpenSearchServer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with OpenSearchServer. 
 *  If not, see <http://www.gnu.org/licenses/>.
 **/
package com.jaeksoft.searchlib.util.pdfbox;

import java.awt.Dimension;
import java.awt.Rectangle;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.util.PDFTextStripper;
import org.apache.pdfbox.util.TextPosition;

public class PDFBoxHighlighter extends PDFTextStripper {

    private final String[] keywords;
    private final Collection<Rectangle> boxes;
    private final Dimension imageDimension;
    private float xFactor;
    private float yFactor;

    public PDFBoxHighlighter(String[] keywords, Collection<Rectangle> boxes, Dimension imageDimension)
            throws IOException {
        this.keywords = keywords;
        this.boxes = boxes;
        this.imageDimension = imageDimension;
    }

    @Override
    protected void startPage(PDPage page) throws IOException {
        super.startPage(page);
        PDRectangle rect = page.findCropBox();
        xFactor = imageDimension.width / rect.getWidth();
        yFactor = imageDimension.height / rect.getHeight();
    }

    @Override
    protected void writeString(String text, List<TextPosition> textPositions) throws IOException {
        super.writeString(text, textPositions);
        if (textPositions == null)
            return;
        StringBuilder term = new StringBuilder();
        List<Rectangle> rects = new ArrayList<Rectangle>();
        for (TextPosition tp : textPositions) {
            String str = tp.getCharacter();
            if (str.length() > 1) {
                handleTerm(term, rects);
                term = new StringBuilder();
                rects.clear();
                addRect(tp, rects);
                handleTerm(str, rects);
                continue;
            }
            char c = str.charAt(0);
            if (!Character.isLetterOrDigit(c)) {
                handleTerm(term, rects);
                term = new StringBuilder();
                rects.clear();
                continue;
            }
            term.append(c);
            addRect(tp, rects);
        }
        handleTerm(term, rects);
    }

    final private void addRect(TextPosition tp, List<Rectangle> rects) {
        Rectangle rect = new Rectangle();
        float xdelta = tp.getWidthDirAdj() * .2F;
        float ydelta = tp.getHeightDir() * .2F;
        rect.x = (int) ((tp.getXDirAdj() - xdelta) * xFactor);
        rect.y = (int) ((tp.getYDirAdj() - (tp.getHeightDir() + ydelta)) * yFactor);
        rect.width = (int) ((tp.getWidthDirAdj() + xdelta * 2) * xFactor);
        rect.height = (int) ((tp.getHeightDir() + ydelta * 2) * yFactor);
        rects.add(rect);
    }

    final private void handleTerm(CharSequence term, List<Rectangle> rects) {
        if (term == null)
            return;
        if (term.length() == 0)
            return;
        if (rects == null)
            return;
        if (rects.size() == 0)
            return;
        String str = term.toString();
        for (String keyword : keywords) {
            if (keyword.equalsIgnoreCase(str)) {
                Rectangle unionRect = new Rectangle(rects.get(0));
                for (Rectangle rect : rects) {
                    if (rect.y != unionRect.y) {
                        unionRect = null;
                        break;
                    }
                    unionRect = unionRect.union(rect);
                }
                if (unionRect != null)
                    boxes.add(unionRect);
                else
                    for (Rectangle rect : rects)
                        boxes.add(rect);
                return;
            }
        }
    }
}