/*
 * 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.
 */

/* $Id: TagLogicalElement.java 1683762 2015-06-05 14:23:11Z ssteiner $ */

package org.apache.fop.afp.modca;

import java.io.IOException;
import java.io.OutputStream;

import org.apache.fop.afp.modca.triplets.AttributeQualifierTriplet;
import org.apache.fop.afp.modca.triplets.AttributeValueTriplet;
import org.apache.fop.afp.modca.triplets.EncodingTriplet;
import org.apache.fop.afp.modca.triplets.FullyQualifiedNameTriplet;
import org.apache.fop.afp.util.BinaryUtils;

A Tag Logical Element structured field assigns an attribute name and an
attribute value to a page or page group. The Tag Logical Element structured
field may be embedded directly in the page or page group, or it may reference
the page or page group from a document index. When a Tag Logical Element
structured field references a page or is embedded in a page following the
active environment group, it is associated with the page. When a Tag Logical
Element structured field references a page group or is embedded in a page
group following the Begin Named Page Group structured field, it is associated
with the page group. When a Tag Logical Element structured field is associated
with a page group, the parameters of the Tag Logical Element structured field
are inherited by all pages in the page group and by all other page groups
that are nested in the page group. The scope of a Tag Logical Element is
determined by its position with respect to other TLEs that reference, or are
embedded in, the same page or page group. The Tag Logical Element structured
field does not provide any presentation specifications and therefore has no
effect on the appearance of a document when it is presented.
/**
 * A Tag Logical Element structured field assigns an attribute name and an
 * attribute value to a page or page group. The Tag Logical Element structured
 * field may be embedded directly in the page or page group, or it may reference
 * the page or page group from a document index. When a Tag Logical Element
 * structured field references a page or is embedded in a page following the
 * active environment group, it is associated with the page. When a Tag Logical
 * Element structured field references a page group or is embedded in a page
 * group following the Begin Named Page Group structured field, it is associated
 * with the page group. When a Tag Logical Element structured field is associated
 * with a page group, the parameters of the Tag Logical Element structured field
 * are inherited by all pages in the page group and by all other page groups
 * that are nested in the page group. The scope of a Tag Logical Element is
 * determined by its position with respect to other TLEs that reference, or are
 * embedded in, the same page or page group. The Tag Logical Element structured
 * field does not provide any presentation specifications and therefore has no
 * effect on the appearance of a document when it is presented.
 */
public class TagLogicalElement extends AbstractTripletStructuredObject {

    
the params of the TLE
/**
     * the params of the TLE
     */
    private State state;

    
Construct a tag logical element with the name and value specified.
Params:
state – the state of the tag logical element/**
     * Construct a tag logical element with the name and value specified.
     *
     * @param state the state of the tag logical element
     */

    public TagLogicalElement(State state) {
        this.state = state;
    }

    private void setAttributeValue(String value) {
        if (state.encoding != -1) {
            addTriplet(new AttributeValueTriplet(value, state.encoding));
        }  else {
            addTriplet(new AttributeValueTriplet(value));
        }
    }

    private void setEncoding(int encoding) {
        if (encoding != State.ENCODING_NONE) {
            addTriplet(new EncodingTriplet(encoding));
        }
    }

    
Sets the attribute qualifier of this structured field
Params:
seqNumber – the attribute sequence number
levNumber – the attribute level number/**
     * Sets the attribute qualifier of this structured field
     *
     * @param seqNumber the attribute sequence number
     * @param levNumber the attribute level number
     */
    public void setAttributeQualifier(int seqNumber, int levNumber) {
        addTriplet(new AttributeQualifierTriplet(seqNumber, levNumber));
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void writeToStream(OutputStream os) throws IOException {
        setFullyQualifiedName(
                FullyQualifiedNameTriplet.TYPE_ATTRIBUTE_GID,
                FullyQualifiedNameTriplet.FORMAT_CHARSTR,
                state.key);
        setAttributeValue(state.value);
        setEncoding(state.encoding);

        byte[] data = new byte[SF_HEADER_LENGTH];
        copySF(data, Type.ATTRIBUTE, Category.PROCESS_ELEMENT);

        int tripletDataLength = getTripletDataLength();
        byte[] l = BinaryUtils.convert(data.length + tripletDataLength - 1, 2);
        data[1] = l[0];
        data[2] = l[1];
        os.write(data);

        writeTriplets(os);
    }

    
Holds the attribute state of a TLE
/**
     *
     * Holds the attribute state of a TLE
     *
     */
    public static class State {

        
 value  interpreted as no encoding
/**
         *  value  interpreted as no encoding
         */
        public static final int ENCODING_NONE = -1;
        
The key attribute /** The key attribute */
        private String key;

        
The value attribute /** The value attribute */
        private String value;

        
The CCSID character et encoding attribute /** The CCSID character et encoding attribute */
        private int encoding =  ENCODING_NONE;


        
Constructor
Params:
key – the key attribute
value – the value attribute/**
         * Constructor
         *
         * @param key the key attribute
         * @param value the value attribute
         */
        public State(String key, String value) {
            this.key = key;
            this.value = value;
        }

        
Params:
key – the key attribute
value – the value attribute
encoding – the CCSID character set encoding attribute/**
         *
         * @param key the key attribute
         * @param value the value attribute
         * @param encoding the CCSID character set encoding attribute
         */
        public State(String key, String value, int encoding) {
            this.key = key;
            this.value = value;
            this.encoding = encoding;
        }


    }
}