001/*
002 * $Id: PdfLayerMembership.java 4784 2011-03-15 08:33:00Z blowagie $
003 *
004 * This file is part of the iText (R) project.
005 * Copyright (c) 1998-2011 1T3XT BVBA
006 * Authors: Bruno Lowagie, Paulo Soares, et al.
007 *
008 * This program is free software; you can redistribute it and/or modify
009 * it under the terms of the GNU Affero General Public License version 3
010 * as published by the Free Software Foundation with the addition of the
011 * following permission added to Section 15 as permitted in Section 7(a):
012 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY 1T3XT,
013 * 1T3XT DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
014 *
015 * This program is distributed in the hope that it will be useful, but
016 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
017 * or FITNESS FOR A PARTICULAR PURPOSE.
018 * See the GNU Affero General Public License for more details.
019 * You should have received a copy of the GNU Affero General Public License
020 * along with this program; if not, see http://www.gnu.org/licenses or write to
021 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
022 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
023 * http://itextpdf.com/terms-of-use/
024 *
025 * The interactive user interfaces in modified source and object code versions
026 * of this program must display Appropriate Legal Notices, as required under
027 * Section 5 of the GNU Affero General Public License.
028 *
029 * In accordance with Section 7(b) of the GNU Affero General Public License,
030 * a covered work must retain the producer line in every PDF that is created
031 * or manipulated using iText.
032 *
033 * You can be released from the requirements of the license by purchasing
034 * a commercial license. Buying such a license is mandatory as soon as you
035 * develop commercial activities involving the iText software without
036 * disclosing the source code of your own applications.
037 * These activities include: offering paid services to customers as an ASP,
038 * serving PDFs on the fly in a web application, shipping iText with a closed
039 * source product.
040 *
041 * For more information, please contact iText Software Corp. at this
042 * address: sales@itextpdf.com
043 */
044package com.itextpdf.text.pdf;
045
046import java.util.Collection;
047import java.util.HashSet;
048
049/**
050 * Content typically belongs to a single optional content group,
051 * and is visible when the group is <B>ON</B> and invisible when it is <B>OFF</B>. To express more
052 * complex visibility policies, content should not declare itself to belong to an optional
053 * content group directly, but rather to an optional content membership dictionary
054 * represented by this class.
055 *
056 * @author Paulo Soares
057 */
058public class PdfLayerMembership extends PdfDictionary implements PdfOCG {
059
060    /**
061     * Visible only if all of the entries are <B>ON</B>.
062     */
063    public static final PdfName ALLON = new PdfName("AllOn");
064    /**
065     * Visible if any of the entries are <B>ON</B>.
066     */
067    public static final PdfName ANYON = new PdfName("AnyOn");
068    /**
069     * Visible if any of the entries are <B>OFF</B>.
070     */
071    public static final PdfName ANYOFF = new PdfName("AnyOff");
072    /**
073     * Visible only if all of the entries are <B>OFF</B>.
074     */
075    public static final PdfName ALLOFF = new PdfName("AllOff");
076
077    PdfIndirectReference ref;
078    PdfArray members = new PdfArray();
079    HashSet<PdfLayer> layers = new HashSet<PdfLayer>();
080
081    /**
082     * Creates a new, empty, membership layer.
083     * @param writer the writer
084     */
085    public PdfLayerMembership(PdfWriter writer) {
086        super(PdfName.OCMD);
087        put(PdfName.OCGS, members);
088        ref = writer.getPdfIndirectReference();
089    }
090
091    /**
092     * Gets the <CODE>PdfIndirectReference</CODE> that represents this membership layer.
093     * @return the <CODE>PdfIndirectReference</CODE> that represents this layer
094     */
095    public PdfIndirectReference getRef() {
096        return ref;
097    }
098
099    /**
100     * Adds a new member to the layer.
101     * @param layer the new member to the layer
102     */
103    public void addMember(PdfLayer layer) {
104        if (!layers.contains(layer)) {
105            members.add(layer.getRef());
106            layers.add(layer);
107        }
108    }
109
110    /**
111     * Gets the member layers.
112     * @return the member layers
113     */
114    public Collection<PdfLayer> getLayers() {
115        return layers;
116    }
117
118    /**
119     * Sets the visibility policy for content belonging to this
120     * membership dictionary. Possible values are ALLON, ANYON, ANYOFF and ALLOFF.
121     * The default value is ANYON.
122     * @param type the visibility policy
123     */
124    public void setVisibilityPolicy(PdfName type) {
125        put(PdfName.P, type);
126    }
127
128    /**
129     * Sets the visibility expression for content belonging to this
130     * membership dictionary.
131     * @param ve A (nested) array of which the first value is /And, /Or, or /Not
132     * followed by a series of indirect references to OCGs or other visibility
133     * expressions.
134     * @since 5.0.2
135     */
136    public void setVisibilityExpression(PdfVisibilityExpression ve) {
137        put(PdfName.VE, ve);
138    }
139
140    /**
141     * Gets the dictionary representing the membership layer. It just returns <CODE>this</CODE>.
142     * @return the dictionary representing the layer
143     */
144    public PdfObject getPdfObject() {
145        return this;
146    }
147}