org.apache.pdfbox.pdmodel.PDPageNode Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of pdfbox Show documentation
The Apache PDFBox library is an open source Java tool for working with PDF documents.
There is a newer version: 3.0.2
/*
 * 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;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.cos.COSBase;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSInteger;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.cos.COSNumber;

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

import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;

/**
 * This represents a page node in a pdf document.
 *
 * @author Ben Litchfield
 * @version $Revision: 1.8 $
 */
public class PDPageNode implements COSObjectable
{
    private COSDictionary page;

    /**
     * Log instance.
     */
    private static final Log log = LogFactory.getLog(PDPageNode.class);

    /**
     * Creates a new instance of PDPage.
     */
    public PDPageNode()
    {
        page = new COSDictionary();
        page.setItem( COSName.TYPE, COSName.PAGES );
        page.setItem( COSName.KIDS, new COSArray() );
        page.setItem( COSName.COUNT, COSInteger.ZERO );
    }

    /**
     * Creates a new instance of PDPage.
     *
     * @param pages The dictionary pages.
     */
    public PDPageNode( COSDictionary pages )
    {
        page = pages;
    }

    /**
     * This will update the count attribute of the page node.  This only needs to
     * be called if you add or remove pages.  The PDDocument will call this for you
     * when you use the PDDocumnet persistence methods.  So, basically most clients
     * will never need to call this.
     *
     * @return The update count for this node.
     */
    public long updateCount()
    {
        long totalCount = 0;
        List kids = getKids();
        Iterator kidIter = kids.iterator();
        while( kidIter.hasNext() )
        {
            Object next = kidIter.next();
            if( next instanceof PDPage )
            {
                totalCount++;
            }
            else
            {
                PDPageNode node = (PDPageNode)next;
                totalCount += node.updateCount();
            }
        }
        page.setLong( COSName.COUNT, totalCount );
        return totalCount;
    }

    /**
     * This will get the count of descendent page objects.
     *
     * @return The total number of descendent page objects.
     */
    public long getCount()
    {
        if(page == null)
        {
            return 0L;
        }
        COSBase num = page.getDictionaryObject(COSName.COUNT);
        if(num == null)
        {
            return 0L;
        }
        return ((COSNumber) num).intValue();
    }

    /**
     * This will get the underlying dictionary that this class acts on.
     *
     * @return The underlying dictionary for this class.
     */
    public COSDictionary getDictionary()
    {
        return page;
    }

    /**
     * This is the parent page node.
     *
     * @return The parent to this page.
     */
    public PDPageNode getParent()
    {
        PDPageNode parent = null;
        COSDictionary parentDic = (COSDictionary)page.getDictionaryObject(COSName.PARENT, COSName.P);
        if( parentDic != null )
        {
            parent = new PDPageNode( parentDic );
        }
        return parent;
    }

    /**
     * This will set the parent of this page.
     *
     * @param parent The parent to this page node.
     */
    public void setParent( PDPageNode parent )
    {
        page.setItem( COSName.PARENT, parent.getDictionary() );
    }

    /**
     * {@inheritDoc}
     */
    public COSBase getCOSObject()
    {
        return page;
    }

    /**
     * This will return all kids of this node, either PDPageNode or PDPage.
     *
     * @return All direct descendents of this node.
     */
    public List getKids()
    {
        List actuals = new ArrayList();
        COSArray kids = getAllKids(actuals, page, false);
        return new COSArrayList( actuals, kids );
    }

    /**
     * This will return all kids of this node as PDPage.
     *
     * @param result All direct and indirect descendents of this node are added to this list.
     */
    public void getAllKids(List result)
    {
        getAllKids(result, page, true);
    }

    /**
     * This will return all kids of the given page node as PDPage.
     *
     * @param result All direct and optionally indirect descendents of this node are added to this list.
     * @param page Page dictionary of a page node.
     * @param recurse if true indirect descendents are processed recursively
     */
    private static COSArray getAllKids(List result, COSDictionary page, boolean recurse)
    {
        if(page == null)
            return null;
        COSArray kids = (COSArray)page.getDictionaryObject( COSName.KIDS );
        if ( kids == null)
        {
            log.error("No Kids found in getAllKids(). Probably a malformed pdf.");
            return null;
        }
        HashSet seen = new HashSet();
        for( int i=0; i