/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * questions.
 */

package javax.xml.bind.annotation;

import org.w3c.dom.Document;
import org.w3c.dom.DocumentFragment;
import org.w3c.dom.Element;
import org.w3c.dom.Node;

import javax.xml.bind.ValidationEventHandler;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.transform.Source;
import javax.xml.transform.dom.DOMResult;
import javax.xml.transform.dom.DOMSource;

/**
 * {@link DomHandler} implementation for W3C DOM (<code>org.w3c.dom</code> package.)
 *
 * @author Kohsuke Kawaguchi
 * @since JAXB2.0
 */
public class W3CDomHandler implements DomHandler<Element,DOMResult> {

    private DocumentBuilder builder;

    /**
     * Default constructor.
     *
     * It is up to a JAXB provider to decide which DOM implementation
     * to use or how that is configured.
     */
    public W3CDomHandler() {
        this.builder = null;
    }

    /**
     * Constructor that allows applications to specify which DOM implementation
     * to be used.
     *
     * @param builder
     *      must not be null. JAXB uses this {@link DocumentBuilder} to create
     *      a new element.
     */
    public W3CDomHandler(DocumentBuilder builder) {
        if(builder==null)
            throw new IllegalArgumentException();
        this.builder = builder;
    }

    public DocumentBuilder getBuilder() {
        return builder;
    }

    public void setBuilder(DocumentBuilder builder) {
        this.builder = builder;
    }

    public DOMResult createUnmarshaller(ValidationEventHandler errorHandler) {
        if(builder==null)
            return new DOMResult();
        else
            return new DOMResult(builder.newDocument());
    }

    public Element getElement(DOMResult r) {
        // JAXP spec is ambiguous about what really happens in this case,
        // so work defensively
        Node n = r.getNode();
        if( n instanceof Document ) {
            return ((Document)n).getDocumentElement();
        }
        if( n instanceof Element )
            return (Element)n;
        if( n instanceof DocumentFragment )
            return (Element)n.getChildNodes().item(0);

        // if the result object contains something strange,
        // it is not a user problem, but it is a JAXB provider's problem.
        // That's why we throw a runtime exception.
        throw new IllegalStateException(n.toString());
    }

    public Source marshal(Element element, ValidationEventHandler errorHandler) {
        return new DOMSource(element);
    }
}