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 * Copyright (c) 2000, 2005, 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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 */

package javax.xml.transform.dom;

import javax.xml.transform.Result;
import org.w3c.dom.Node;

/**
 * Acts as a holder for a transformation result tree
 * in the form of a Document Object Model (DOM) tree.
 *
 * <p>If no output DOM source is set, the transformation will create
 * a Document node as the holder for the result of the transformation,
 * which may be retrieved with {@link #getNode()}.
 *
 * @author <a href="Jeff.Suttor@Sun.com">Jeff Suttor</a>
 * @since 1.4
 */
public class DOMResult implements Result {

    /**
     * If {@link javax.xml.transform.TransformerFactory#getFeature}
     * returns {@code true} when passed this value as an argument,
     * the {@code Transformer} supports {@code Result} output of this type.
     */
    public static final String FEATURE = "http://javax.xml.transform.dom.DOMResult/feature";

    /**
     * Zero-argument default constructor.
     *
     * <p>{@code node},
     * {@code siblingNode} and
     * {@code systemId}
     * will be set to {@code null}.
     */
    public DOMResult() {
        setNode(null);
        setNextSibling(null);
        setSystemId(null);
    }

    /**
     * Use a DOM node to create a new output target.
     *
     * <p>In practice, the node should be
     * a {@link org.w3c.dom.Document} node,
     * a {@link org.w3c.dom.DocumentFragment} node, or
     * a {@link org.w3c.dom.Element} node.
     * In other words, a node that accepts children.
     *
     * <p>{@code siblingNode} and
     * {@code systemId}
     * will be set to {@code null}.
     *
     * @param node The DOM node that will contain the result tree.
     */
    public DOMResult(Node node) {
        setNode(node);
        setNextSibling(null);
        setSystemId(null);
    }

    /**
     * Use a DOM node to create a new output target with the specified System ID.
     *
     * <p>In practice, the node should be
     * a {@link org.w3c.dom.Document} node,
     * a {@link org.w3c.dom.DocumentFragment} node, or
     * a {@link org.w3c.dom.Element} node.
     * In other words, a node that accepts children.
     *
     * <p>{@code siblingNode} will be set to {@code null}.
     *
     * @param node The DOM node that will contain the result tree.
     * @param systemId The system identifier which may be used in association with this node.
     */
    public DOMResult(Node node, String systemId) {
        setNode(node);
        setNextSibling(null);
        setSystemId(systemId);
    }

    /**
     * Use a DOM node to create a new output target specifying
     * the child node where the result nodes should be inserted before.
     *
     * <p>In practice, {@code node} and {@code nextSibling} should be
     * a {@link org.w3c.dom.Document} node,
     * a {@link org.w3c.dom.DocumentFragment} node, or
     * a {@link org.w3c.dom.Element} node.
     * In other words, a node that accepts children.
     *
     * <p>Use {@code nextSibling} to specify the child node
     * where the result nodes should be inserted before.
     * If {@code nextSibling} is not a sibling of {@code node},
     * then an {@code IllegalArgumentException} is thrown.
     * If {@code node} is {@code null} and {@code nextSibling} is not {@code null},
     * then an {@code IllegalArgumentException} is thrown.
     * If {@code nextSibling} is {@code null},
     * then the behavior is the same as calling {@link #DOMResult(Node node)},
     * i.e. append the result nodes as the last child of the specified {@code node}.
     *
     * <p>{@code systemId} will be set to {@code null}.
     *
     * @param node The DOM node that will contain the result tree.
     * @param nextSibling The child node where the result nodes should be inserted before.
     *
     * @throws IllegalArgumentException If {@code nextSibling} is not a sibling of {@code node} or
     *   {@code node} is {@code null} and {@code nextSibling}
     *   is not {@code null}.
     *
     * @since 1.5
     */
    public DOMResult(Node node, Node nextSibling) {

        // does the corrent parent/child relationship exist?
        if (nextSibling != null) {
            // cannot be a sibling of a null node
            if (node == null) {
                throw new IllegalArgumentException("Cannot create a DOMResult when the nextSibling is contained by the \"null\" node.");
            }

            // nextSibling contained by node?
            if ((node.compareDocumentPosition(nextSibling)&Node.DOCUMENT_POSITION_CONTAINED_BY)==0) {
                throw new IllegalArgumentException("Cannot create a DOMResult when the nextSibling is not contained by the node.");
            }
        }

        setNode(node);
        setNextSibling(nextSibling);
        setSystemId(null);
    }

    /**
     * Use a DOM node to create a new output target specifying the child
     * node where the result nodes should be inserted before and
     * the specified System ID.
     *
     * <p>In practice, {@code node} and {@code nextSibling} should be
     * a {@link org.w3c.dom.Document} node,
     * a {@link org.w3c.dom.DocumentFragment} node, or a
     * {@link org.w3c.dom.Element} node.
     * In other words, a node that accepts children.
     *
     * <p>Use {@code nextSibling} to specify the child node
     * where the result nodes should be inserted before.
     * If {@code nextSibling} is not a sibling of {@code node},
     * then an {@code IllegalArgumentException} is thrown.
     * If {@code node} is {@code null} and {@code nextSibling} is not {@code null},
     * then an {@code IllegalArgumentException} is thrown.
     * If {@code nextSibling} is {@code null},
     * then the behavior is the same as calling {@link #DOMResult(Node node, String systemId)},
     * i.e. append the result nodes as the last child of the specified
     * node and use the specified System ID.
     *
     * @param node The DOM node that will contain the result tree.
     * @param nextSibling The child node where the result nodes should be inserted before.
     * @param systemId The system identifier which may be used in association with this node.
     *
     * @throws IllegalArgumentException If {@code nextSibling} is not a
     *   sibling of {@code node} or
     *   {@code node} is {@code null} and {@code nextSibling}
     *   is not {@code null}.
     *
     * @since 1.5
     */
    public DOMResult(Node node, Node nextSibling, String systemId) {

        // does the corrent parent/child relationship exist?
        if (nextSibling != null) {
            // cannot be a sibling of a null node
            if (node == null) {
                throw new IllegalArgumentException("Cannot create a DOMResult when the nextSibling is contained by the \"null\" node.");
            }

            // nextSibling contained by node?
            if ((node.compareDocumentPosition(nextSibling)&Node.DOCUMENT_POSITION_CONTAINED_BY)==0) {
                throw new IllegalArgumentException("Cannot create a DOMResult when the nextSibling is not contained by the node.");
            }
        }

        setNode(node);
        setNextSibling(nextSibling);
        setSystemId(systemId);
    }

    /**
     * Set the node that will contain the result DOM tree.
     *
     * <p>In practice, the node should be
     * a {@link org.w3c.dom.Document} node,
     * a {@link org.w3c.dom.DocumentFragment} node, or
     * a {@link org.w3c.dom.Element} node.
     * In other words, a node that accepts children.
     *
     * <p>An {@code IllegalStateException} is thrown if
     * {@code nextSibling} is not {@code null} and
     * {@code node} is not a parent of {@code nextSibling}.
     * An {@code IllegalStateException} is thrown if {@code node} is {@code null} and
     * {@code nextSibling} is not {@code null}.
     *
     * @param node The node to which the transformation will be appended.
     *
     * @throws IllegalStateException If {@code nextSibling} is not
     *   {@code null} and
     *   {@code nextSibling} is not a child of {@code node} or
     *   {@code node} is {@code null} and
     *   {@code nextSibling} is not {@code null}.
     */
    public void setNode(Node node) {
        // does the corrent parent/child relationship exist?
        if (nextSibling != null) {
            // cannot be a sibling of a null node
            if (node == null) {
                throw new IllegalStateException("Cannot create a DOMResult when the nextSibling is contained by the \"null\" node.");
            }

            // nextSibling contained by node?
            if ((node.compareDocumentPosition(nextSibling)&Node.DOCUMENT_POSITION_CONTAINED_BY)==0) {
                throw new IllegalArgumentException("Cannot create a DOMResult when the nextSibling is not contained by the node.");
            }
        }

        this.node = node;
    }

    /**
     * Get the node that will contain the result DOM tree.
     *
     * <p>If no node was set via
     * {@link #DOMResult(Node node)},
     * {@link #DOMResult(Node node, String systeId)},
     * {@link #DOMResult(Node node, Node nextSibling)},
     * {@link #DOMResult(Node node, Node nextSibling, String systemId)} or
     * {@link #setNode(Node node)},
     * then the node will be set by the transformation, and may be obtained from this method once the transformation is complete.
     * Calling this method before the transformation will return {@code null}.
     *
     * @return The node to which the transformation will be appended.
     */
    public Node getNode() {
        return node;
    }

    /**
     * Set the child node before which the result nodes will be inserted.
     *
     * <p>Use {@code nextSibling} to specify the child node
     * before which the result nodes should be inserted.
     * If {@code nextSibling} is not a descendant of {@code node},
     * then an {@code IllegalArgumentException} is thrown.
     * If {@code node} is {@code null} and {@code nextSibling} is not {@code null},
     * then an {@code IllegalStateException} is thrown.
     * If {@code nextSibling} is {@code null},
     * then the behavior is the same as calling {@link #DOMResult(Node node)},
     * i.e. append the result nodes as the last child of the specified {@code node}.
     *
     * @param nextSibling The child node before which the result nodes will be inserted.
     *
     * @throws IllegalArgumentException If {@code nextSibling} is not a
     *   descendant of {@code node}.
     * @throws IllegalStateException If {@code node} is {@code null}
     *   and {@code nextSibling} is not {@code null}.
     *
     * @since 1.5
     */
    public void setNextSibling(Node nextSibling) {

        // does the corrent parent/child relationship exist?
        if (nextSibling != null) {
            // cannot be a sibling of a null node
            if (node == null) {
                throw new IllegalStateException("Cannot create a DOMResult when the nextSibling is contained by the \"null\" node.");
            }

            // nextSibling contained by node?
            if ((node.compareDocumentPosition(nextSibling)&Node.DOCUMENT_POSITION_CONTAINED_BY)==0) {
                throw new IllegalArgumentException("Cannot create a DOMResult when the nextSibling is not contained by the node.");
            }
        }

        this.nextSibling = nextSibling;
    }

    /**
     * Get the child node before which the result nodes will be inserted.
     *
     * <p>If no node was set via
     * {@link #DOMResult(Node node, Node nextSibling)},
     * {@link #DOMResult(Node node, Node nextSibling, String systemId)} or
     * {@link #setNextSibling(Node nextSibling)},
     * then {@code null} will be returned.
     *
     * @return The child node before which the result nodes will be inserted.
     *
     * @since 1.5
     */
    public Node getNextSibling() {
        return nextSibling;
    }

    /**
     * Set the systemId that may be used in association with the node.
     *
     * @param systemId The system identifier as a URI string.
     */
    public void setSystemId(String systemId) {
        this.systemId = systemId;
    }

    /**
     * Get the System Identifier.
     *
     * <p>If no System ID was set via
     * {@link #DOMResult(Node node, String systemId)},
     * {@link #DOMResult(Node node, Node nextSibling, String systemId)} or
     * {@link #setSystemId(String systemId)},
     * then {@code null} will be returned.
     *
     * @return The system identifier.
     */
    public String getSystemId() {
        return systemId;
    }

    //////////////////////////////////////////////////////////////////////
    // Internal state.
    //////////////////////////////////////////////////////////////////////

    /**
     * The node to which the transformation will be appended.
     */
    private Node node = null;

    /**
     * The child node before which the result nodes will be inserted.
     *
     * @since 1.5
     */
    private Node nextSibling = null;

    /**
     * The System ID that may be used in association with the node.
     */
    private String systemId = null;
}
