org.apache.pdfbox.pdmodel.interactive.pagenavigation.PDThreadBead.java Source code

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Here is the source code for org.apache.pdfbox.pdmodel.interactive.pagenavigation.PDThreadBead.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.pdfbox.pdmodel.interactive.pagenavigation;

import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSName;

import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.common.COSObjectable;
import org.apache.pdfbox.pdmodel.common.PDRectangle;

/**
 * This a single bead in a thread in a PDF document.
 *
 * @author Ben Litchfield
 */
public class PDThreadBead implements COSObjectable {

    private final COSDictionary bead;

    /**
     * Constructor that is used for a preexisting dictionary.
     *
     * @param b The underlying dictionary.
     */
    public PDThreadBead(COSDictionary b) {
        bead = b;
    }

    /**
     * Default constructor.
     *
     */
    public PDThreadBead() {
        bead = new COSDictionary();
        bead.setName("Type", "Bead");
        setNextBead(this);
        setPreviousBead(this);
    }

    /**
     * This will get the underlying dictionary that this object wraps.
     *
     * @return The underlying info dictionary.
     */
    @Override
    public COSDictionary getCOSObject() {
        return bead;
    }

    /**
     * This will get the thread that this bead is part of.  This is only required
     * for the first bead in a thread, so other beads 'may' return null.
     *
     * @return The thread that this bead is part of.
     */
    public PDThread getThread() {
        PDThread retval = null;
        COSDictionary dic = (COSDictionary) bead.getDictionaryObject("T");
        if (dic != null) {
            retval = new PDThread(dic);
        }
        return retval;
    }

    /**
     * Set the thread that this bead is part of.  This is only required for the
     * first bead in a thread.  Note: This property is set for you by the PDThread.setFirstBead() method.
     *
     * @param thread The thread that this bead is part of.
     */
    public void setThread(PDThread thread) {
        bead.setItem("T", thread);
    }

    /**
     * This will get the next bead.  If this bead is the last bead in the list then this
     * will return the first bead.
     *
     * @return The next bead in the list or the first bead if this is the last bead.
     */
    public PDThreadBead getNextBead() {
        return new PDThreadBead((COSDictionary) bead.getDictionaryObject("N"));
    }

    /**
     * Set the next bead in the thread.
     *
     * @param next The next bead.
     */
    protected final void setNextBead(PDThreadBead next) {
        bead.setItem("N", next);
    }

    /**
     * This will get the previous bead.  If this bead is the first bead in the list then this
     * will return the last bead.
     *
     * @return The previous bead in the list or the last bead if this is the first bead.
     */
    public PDThreadBead getPreviousBead() {
        return new PDThreadBead((COSDictionary) bead.getDictionaryObject("V"));
    }

    /**
     * Set the previous bead in the thread.
     *
     * @param previous The previous bead.
     */
    protected final void setPreviousBead(PDThreadBead previous) {
        bead.setItem("V", previous);
    }

    /**
     * Append a bead after this bead.  This will correctly set the next/previous beads in the
     * linked list.
     *
     * @param append The bead to insert.
     */
    public void appendBead(PDThreadBead append) {
        PDThreadBead nextBead = getNextBead();
        nextBead.setPreviousBead(append);
        append.setNextBead(nextBead);
        setNextBead(append);
        append.setPreviousBead(this);
    }

    /**
     * Get the page that this bead is part of.
     *
     * @return The page that this bead is part of.
     */
    public PDPage getPage() {
        PDPage page = null;
        COSDictionary dic = (COSDictionary) bead.getDictionaryObject("P");
        if (dic != null) {
            page = new PDPage(dic);
        }
        return page;
    }

    /**
     * Set the page that this bead is part of.  This is a required property and must be
     * set when creating a new bead.  The PDPage object also has a list of beads in the natural
     * reading order.  It is recommended that you add this object to that list as well.
     *
     * @param page The page that this bead is on.
     */
    public void setPage(PDPage page) {
        bead.setItem("P", page);
    }

    /**
     * The rectangle on the page that this bead is part of.
     *
     * @return The part of the page that this bead covers.
     */
    public PDRectangle getRectangle() {
        PDRectangle rect = null;
        COSArray array = (COSArray) bead.getDictionaryObject(COSName.R);
        if (array != null) {
            rect = new PDRectangle(array);
        }
        return rect;
    }

    /**
     * Set the rectangle on the page that this bead covers.
     *
     * @param rect The portion of the page that this bead covers.
     */
    public void setRectangle(PDRectangle rect) {
        bead.setItem(COSName.R, rect);
    }
}