Value.java

/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is part of dcm4che, an implementation of DICOM(TM) in
 * Java(TM), hosted at https://github.com/gunterze/dcm4che.
 *
 * The Initial Developer of the Original Code is
 * Agfa Healthcare.
 * Portions created by the Initial Developer are Copyright (C) 2011
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * See @authors listed below
 *
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 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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package org.dcm4che3.data;

import java.io.IOException;

import org.dcm4che3.io.DicomEncodingOptions;
import org.dcm4che3.io.DicomOutputStream;
import org.dcm4che3.util.ByteUtils;

public interface Value {
    
    final Value NULL = new Value() {

        @Override
        public boolean isEmpty() {
            return true;
        }

        @Override
        public int getEncodedLength(DicomEncodingOptions encOpts, boolean explicitVR, VR vr) {
            return vr == VR.SQ && encOpts.undefEmptySequenceLength ? -1 : 0;
        }

        @Override
        public void writeTo(DicomOutputStream dos, VR vr) throws IOException {
        }

        @Override
        public int calcLength(DicomEncodingOptions encOpts, boolean explicitVR, VR vr) {
             return vr == VR.SQ && encOpts.undefEmptySequenceLength  ? 8 : 0;
        }

        @Override
        public String toString() {
            return "";
        }

        @Override
        public byte[] toBytes(VR vr, boolean bigEndian) {
            return ByteUtils.EMPTY_BYTES;
        }
    };

    boolean isEmpty();

    byte[] toBytes(VR vr, boolean bigEndian) throws IOException;

    void writeTo(DicomOutputStream out, VR vr) throws IOException;

    int calcLength(DicomEncodingOptions encOpts, boolean explicitVR, VR vr);

    int getEncodedLength(DicomEncodingOptions encOpts, boolean explicitVR, VR vr);

}