/*
 * 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: VersionController.java 1611834 2014-07-18 23:05:19Z lbernardo $ */

package org.apache.fop.pdf;

import org.apache.fop.pdf.StandardStructureAttributes.Table.Scope;

An abstraction that controls the mutability of the PDF version for a document.
/**
 * An abstraction that controls the mutability of the PDF version for a document.
 */
public abstract class VersionController {

    private Version version;

    private VersionController(Version version) {
        this.version = version;
    }

    
Returns the PDF version of the document.
Returns:
the PDF version/**
     * Returns the PDF version of the document.
     *
     * @return the PDF version
     */
    public Version getPDFVersion() {
        return version;
    }

    
Sets the PDF version of the document.
Params:
version – the PDF version
Throws:
IllegalStateException – if the PDF version is not allowed to change./**
     * Sets the PDF version of the document.
     *
     * @param version the PDF version
     * @throws IllegalStateException if the PDF version is not allowed to change.
     */
    public abstract void setPDFVersion(Version version);

    abstract void addTableHeaderScopeAttribute(PDFStructElem th, Scope scope);

    @Override
    public String toString() {
        return version.toString();
    }

    
A class representing the version of a PDF document. This class doesn't allow the version to
change once it has been set, it is immutable. Any attempt to set the version will result in
an exception being thrown.
/**
     * A class representing the version of a PDF document. This class doesn't allow the version to
     * change once it has been set, it is immutable. Any attempt to set the version will result in
     * an exception being thrown.
     */
    private static final class FixedVersion extends VersionController {

        private FixedVersion(Version version) {
            super(version);
        }

        @Override
        public void setPDFVersion(Version version) {
            if (super.version.compareTo(version) != 0) {
                throw new IllegalStateException("Cannot change the version of this PDF document.");
            }
        }

        @Override
        void addTableHeaderScopeAttribute(PDFStructElem th, Scope scope) {
            if (super.version.compareTo(Version.V1_4) > 0) {
                Scope.addScopeAttribute(th, scope);
            }
        }
    }

    
A class representing the version of a PDF document. This class allows the version to be
changed once it has been set (it is mutable) ONLY if the new version is greater. If the PDF
version is changed after it has been instantiated, the version will be set in the document
catalog.
/**
     * A class representing the version of a PDF document. This class allows the version to be
     * changed once it has been set (it is mutable) ONLY if the new version is greater. If the PDF
     * version is changed after it has been instantiated, the version will be set in the document
     * catalog.
     */
    private static final class DynamicVersion extends VersionController {

        private PDFDocument doc;

        private DynamicVersion(Version version, PDFDocument doc) {
            super(version);
            this.doc = doc;
        }

        @Override
        public void setPDFVersion(Version version) {
            if (super.version.compareTo(version) < 0) {
                super.version = version;
                doc.getRoot().setVersion(version);
            }
        }

        @Override
        void addTableHeaderScopeAttribute(PDFStructElem th, Scope scope) {
            setPDFVersion(Version.V1_5);
            Scope.addScopeAttribute(th, scope);
        }
    }

    
Returns a controller that disallows subsequent change to the document's version. The minimum
allowed version is v1.4.
Params:
version – the PDF version (must be >= v1.4)
Returns:
the fixed PDF version controller/**
     * Returns a controller that disallows subsequent change to the document's version. The minimum
     * allowed version is v1.4.
     *
     * @param version the PDF version (must be &gt;= v1.4)
     * @return the fixed PDF version controller
     */
    public static VersionController getFixedVersionController(Version version) {
        if (version.compareTo(Version.V1_4) < 0) {
            throw new IllegalArgumentException("The PDF version cannot be set below version 1.4");
        }
        return new FixedVersion(version);
    }

    
Returns a controller that allows subsequent changes to the document's version.
Params:
initialVersion – the initial PDF version
doc – the document whose version is being set
Returns:
the dynamic PDF version controller/**
     * Returns a controller that allows subsequent changes to the document's version.
     *
     * @param initialVersion the initial PDF version
     * @param doc the document whose version is being set
     * @return the dynamic PDF version controller
     */
    public static VersionController getDynamicVersionController(Version initialVersion,
            PDFDocument doc) {
        return new DynamicVersion(initialVersion, doc);
    }
}