001/* ***** BEGIN LICENSE BLOCK *****
002 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
003 *
004 * The contents of this file are subject to the Mozilla Public License Version
005 * 1.1 (the "License"); you may not use this file except in compliance with
006 * the License. You may obtain a copy of the License at
007 * http://www.mozilla.org/MPL/
008 *
009 * Software distributed under the License is distributed on an "AS IS" basis,
010 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
011 * for the specific language governing rights and limitations under the
012 * License.
013 *
014 * The Original Code is part of dcm4che, an implementation of DICOM(TM) in
015 * Java(TM), hosted at https://github.com/gunterze/dcm4che.
016 *
017 * The Initial Developer of the Original Code is
018 * Agfa Healthcare.
019 * Portions created by the Initial Developer are Copyright (C) 2011
020 * the Initial Developer. All Rights Reserved.
021 *
022 * Contributor(s):
023 * See @authors listed below
024 *
025 * Alternatively, the contents of this file may be used under the terms of
026 * either the GNU General Public License Version 2 or later (the "GPL"), or
027 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
028 * in which case the provisions of the GPL or the LGPL are applicable instead
029 * of those above. If you wish to allow use of your version of this file only
030 * under the terms of either the GPL or the LGPL, and not to allow others to
031 * use your version of this file under the terms of the MPL, indicate your
032 * decision by deleting the provisions above and replace them with the notice
033 * and other provisions required by the GPL or the LGPL. If you do not delete
034 * the provisions above, a recipient may use your version of this file under
035 * the terms of any one of the MPL, the GPL or the LGPL.
036 *
037 * ***** END LICENSE BLOCK ***** */
038
039package org.dcm4che3.data;
040
041import java.io.IOException;
042
043import org.dcm4che3.io.DicomEncodingOptions;
044import org.dcm4che3.io.DicomOutputStream;
045import org.dcm4che3.util.ByteUtils;
046
047public interface Value {
048    
049    final Value NULL = new Value() {
050
051        @Override
052        public boolean isEmpty() {
053            return true;
054        }
055
056        @Override
057        public int getEncodedLength(DicomEncodingOptions encOpts, boolean explicitVR, VR vr) {
058            return vr == VR.SQ && encOpts.undefEmptySequenceLength ? -1 : 0;
059        }
060
061        @Override
062        public void writeTo(DicomOutputStream dos, VR vr) throws IOException {
063        }
064
065        @Override
066        public int calcLength(DicomEncodingOptions encOpts, boolean explicitVR, VR vr) {
067             return vr == VR.SQ && encOpts.undefEmptySequenceLength  ? 8 : 0;
068        }
069
070        @Override
071        public String toString() {
072            return "";
073        }
074
075        @Override
076        public byte[] toBytes(VR vr, boolean bigEndian) {
077            return ByteUtils.EMPTY_BYTES;
078        }
079    };
080
081    boolean isEmpty();
082
083    byte[] toBytes(VR vr, boolean bigEndian) throws IOException;
084
085    void writeTo(DicomOutputStream out, VR vr) throws IOException;
086
087    int calcLength(DicomEncodingOptions encOpts, boolean explicitVR, VR vr);
088
089    int getEncodedLength(DicomEncodingOptions encOpts, boolean explicitVR, VR vr);
090
091}