/*
 * 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: ElementMapping.java 1610839 2014-07-15 20:25:58Z vhennebert $ */

package org.apache.fop.fo;

import java.util.HashMap;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.DOMImplementation;

import org.apache.xmlgraphics.util.QName;

Abstract base class for Element Mappings (including FO Element Mappings)
which provide the framework of valid elements and attributes for a given
namespace.
/**
 * Abstract base class for Element Mappings (including FO Element Mappings)
 * which provide the framework of valid elements and attributes for a given
 * namespace.
 */
public abstract class ElementMapping {
    
constant for defining the default value /** constant for defining the default value */
    public static final String DEFAULT = "<default>";

    
The HashMap table of formatting objects defined by the ElementMapping /** The HashMap table of formatting objects defined by the ElementMapping */
    protected HashMap<String, Maker> foObjs;
    //Please don't change that to java.util.Map as that can break extensions.

    
The namespace for the ElementMapping /** The namespace for the ElementMapping */
    protected String namespaceURI;

    
Returns a HashMap of maker objects for this element mapping
Returns:
Table of Maker objects for this ElementMapping/**
     * Returns a HashMap of maker objects for this element mapping
     *
     * @return Table of Maker objects for this ElementMapping
     */
    public HashMap<String, Maker> getTable() {
        if (foObjs == null) {
            initialize();
        }
        return foObjs;
    }

    
Returns the namespace URI for this element mapping
Returns:
Namespace URI for this element mapping/**
     * Returns the namespace URI for this element mapping
     *
     * @return Namespace URI for this element mapping
     */
    public String getNamespaceURI() {
        return namespaceURI;
    }

    
Returns the DOMImplementation used by this ElementMapping. The value returned may be null
for cases where no DOM is used to represent the element tree (XSL-FO, for example). This
method is used by the intermediate format to instantiate the right kind of DOM document
for foreign objects. For example, SVG handled through Apache Batik has to use a special
DOMImplementation.
Returns:
the DOMImplementation used by this ElementMapping, may be null/**
     * Returns the DOMImplementation used by this ElementMapping. The value returned may be null
     * for cases where no DOM is used to represent the element tree (XSL-FO, for example). This
     * method is used by the intermediate format to instantiate the right kind of DOM document
     * for foreign objects. For example, SVG handled through Apache Batik has to use a special
     * DOMImplementation.
     * @return the DOMImplementation used by this ElementMapping, may be null
     */
    public DOMImplementation getDOMImplementation() {
        return null; //For namespaces not used in foreign objects
    }

    
Returns:
the default DOMImplementation when no specialized DOM is necessary./**
     * @return the default DOMImplementation when no specialized DOM is necessary.
     */
    public static DOMImplementation getDefaultDOMImplementation() {
        DocumentBuilderFactory fact = DocumentBuilderFactory.newInstance();
        fact.setNamespaceAware(true);
        fact.setValidating(false);
        try {
            return fact.newDocumentBuilder().getDOMImplementation();
        } catch (ParserConfigurationException e) {
            throw new RuntimeException(
                    "Cannot return default DOM implementation: " + e.getMessage());
        }
    }

    
Returns:
the standard namespace prefix for this namespace or null if it is not known./** @return the standard namespace prefix for this namespace or null if it is not known. */
    public String getStandardPrefix() {
        return null;
    }

    
Indicates whether a particular attribute of the namespace is a property, i.e. the attribute
value should be converted to a property value.
Params:
attributeName – the attribute name
Returns:
true if the attribute should be converted to a property/**
     * Indicates whether a particular attribute of the namespace is a property, i.e. the attribute
     * value should be converted to a property value.
     * @param attributeName the attribute name
     * @return true if the attribute should be converted to a property
     */
    public boolean isAttributeProperty(QName attributeName) {
        return false;
    }

    
Initializes the set of maker objects associated with this ElementMapping
/**
     * Initializes the set of maker objects associated with this ElementMapping
     */
    protected abstract void initialize();

    
Base class for all Makers. It is responsible to return the right kind of FONode for a
particular element.
/**
     * Base class for all Makers. It is responsible to return the right kind of FONode for a
     * particular element.
     */
    public static class Maker {

        
Creates a new FONode (or rather a specialized subclass of it).
Params:
parent – the parent FONode
Returns:
the newly created FONode instance/**
         * Creates a new FONode (or rather a specialized subclass of it).
         * @param parent the parent FONode
         * @return the newly created FONode instance
         */
        public FONode make(FONode parent) {
            return null;
        }
    }
}