/*
 * Copyright (c) 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.xml.internal.stream.events ;

import java.io.IOException;
import java.io.Writer;
import javax.xml.stream.events.XMLEvent;
import javax.xml.stream.events.Characters;
import javax.xml.stream.events.EndElement;
import javax.xml.stream.events.StartElement;
import javax.xml.namespace.QName;
import javax.xml.stream.Location;
import javax.xml.stream.XMLStreamException;

DummyEvent is an abstract class. It provides functionality for most of the
function of XMLEvent.
Author:
Neeraj Bajaj Sun Microsystems,Inc., K.Venugopal Sun Microsystems,Inc./** DummyEvent is an abstract class. It provides functionality for most of the
 * function of XMLEvent.
 *
 * @author Neeraj Bajaj Sun Microsystems,Inc.
 * @author K.Venugopal Sun Microsystems,Inc.
 *
 */

public abstract class DummyEvent implements XMLEvent {
    // Make sure that getLocation() never returns null. Instead, return this dummy location
    // that indicates "nowhere" as effectively as possible.
    private static DummyLocation nowhere = new DummyLocation();

    /* Event type this event corresponds to */
    private int fEventType;
    protected Location fLocation = (Location) nowhere;

    public DummyEvent() {
    }

    public DummyEvent(int i) {
        fEventType = i;
    }

    public int getEventType() {
        return fEventType;
    }

    protected void setEventType(int eventType){
        fEventType = eventType;
    }


    public boolean isStartElement() {
        return fEventType == XMLEvent.START_ELEMENT;
    }

    public boolean isEndElement() {
        return fEventType == XMLEvent.END_ELEMENT;
    }

    public boolean isEntityReference() {
        return fEventType == XMLEvent.ENTITY_REFERENCE;
    }

    public boolean isProcessingInstruction() {
        return fEventType == XMLEvent.PROCESSING_INSTRUCTION;
    }

    public boolean isCharacterData() {
        return fEventType == XMLEvent.CHARACTERS;
    }

    public boolean isStartDocument() {
        return fEventType == XMLEvent.START_DOCUMENT;
    }

    public boolean isEndDocument() {
        return fEventType == XMLEvent.END_DOCUMENT;
    }

    public Location getLocation(){
        return fLocation;
    }

    void setLocation(Location loc){
        if (loc == null) {
            fLocation = nowhere;
        } else {
            fLocation = loc;
        }
    }

    
Returns this event as Characters, may result in
a class cast exception if this event is not Characters.
/** Returns this event as Characters, may result in
     * a class cast exception if this event is not Characters.
     */
    public Characters asCharacters() {
        return (Characters)this;
    }

    
Returns this event as an end  element event, may result in
a class cast exception if this event is not a end element.
/** Returns this event as an end  element event, may result in
     * a class cast exception if this event is not a end element.
     */
    public EndElement asEndElement() {
        return (EndElement)this;
    }

    
Returns this event as a start element event, may result in
a class cast exception if this event is not a start element.
/** Returns this event as a start element event, may result in
     * a class cast exception if this event is not a start element.
     */
    public StartElement asStartElement() {
        return (StartElement)this;
    }

    
This method is provided for implementations to provide
optional type information about the associated event.
It is optional and will return null if no information
is available.
/** This method is provided for implementations to provide
     * optional type information about the associated event.
     * It is optional and will return null if no information
     * is available.
     */
    public QName getSchemaType() {
        //Base class will take care of providing extra information about this event.
        return null;
    }

    
A utility function to check if this event is an Attribute.
See Also:
Attribute/** A utility function to check if this event is an Attribute.
     * @see Attribute
     */
    public boolean isAttribute() {
        return fEventType == XMLEvent.ATTRIBUTE;
    }

    
A utility function to check if this event is Characters.
See Also:
Characters/** A utility function to check if this event is Characters.
     * @see Characters
     */
    public boolean isCharacters() {
        return fEventType == XMLEvent.CHARACTERS;
    }

    
A utility function to check if this event is a Namespace.
See Also:
Namespace/** A utility function to check if this event is a Namespace.
     * @see Namespace
     */
    public boolean isNamespace() {
        return fEventType == XMLEvent.NAMESPACE;
    }

    
This method will write the XMLEvent as per the XML 1.0 specification as Unicode characters.
No indentation or whitespace should be outputted.
Any user defined event type SHALL have this method
called when being written to on an output stream.
Built in Event types MUST implement this method,
but implementations MAY choose not call these methods
for optimizations reasons when writing out built in
Events to an output stream.
The output generated MUST be equivalent in terms of the
infoset expressed.
Params:
writer – The writer that will output the data
Throws:
XMLStreamException – if there is a fatal error writing the event/** This method will write the XMLEvent as per the XML 1.0 specification as Unicode characters.
     * No indentation or whitespace should be outputted.
     *
     * Any user defined event type SHALL have this method
     * called when being written to on an output stream.
     * Built in Event types MUST implement this method,
     * but implementations MAY choose not call these methods
     * for optimizations reasons when writing out built in
     * Events to an output stream.
     * The output generated MUST be equivalent in terms of the
     * infoset expressed.
     *
     * @param writer The writer that will output the data
     * @throws XMLStreamException if there is a fatal error writing the event
     */
    public void writeAsEncodedUnicode(Writer writer) throws XMLStreamException {
        try {
            writeAsEncodedUnicodeEx(writer);
        } catch (IOException e) {
            throw new XMLStreamException(e);
        }
    }
    
Helper method in order to expose IOException.
Params:
writer – The writer that will output the data
Throws:
XMLStreamException – if there is a fatal error writing the event
IOException – if there is an IO error/** Helper method in order to expose IOException.
     * @param writer The writer that will output the data
     * @throws XMLStreamException if there is a fatal error writing the event
     * @throws IOException if there is an IO error
     */
    protected abstract void writeAsEncodedUnicodeEx(Writer writer)
        throws IOException, XMLStreamException;

    
Helper method to escape < > & for characters event and
 quotes, lt and amps for Entity
/** Helper method to escape < > & for characters event and
     *  quotes, lt and amps for Entity
     */
    protected void charEncode(Writer writer, String data)
        throws IOException
    {
        if (data == null || data == "") return;
        int i = 0, start = 0;
        int len = data.length();

        loop:
        for (; i < len; ++i) {
            switch (data.charAt(i)) {
            case '<':
                writer.write(data, start, i - start);
                writer.write("&lt;");
                start = i + 1;
                break;

            case '&':
                writer.write(data, start, i - start);
                writer.write("&amp;");
                start = i + 1;
                break;

            case '>':
                writer.write(data, start, i - start);
                writer.write("&gt;");
                start = i + 1;
                break;
            case '"':
                writer.write(data, start, i - start);
                writer.write("&quot;");
                start = i + 1;
                break;
            }
        }
        // Write any pending data
        writer.write(data, start, len - start);
    }

    static class DummyLocation implements Location {
        public DummyLocation() {
        }

        public int getCharacterOffset() {
            return -1;
        }

        public int getColumnNumber() {
            return -1;
        }

        public int getLineNumber() {
            return -1;
        }

        public String getPublicId() {
            return null;
        }

        public String getSystemId() {
            return null;
        }
    }
}