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package com.sun.xml.internal.fastinfoset.stax.events;

import javax.xml.stream.XMLEventFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.events.Namespace;
import javax.xml.stream.events.XMLEvent;
import javax.xml.stream.util.XMLEventAllocator;
import javax.xml.stream.util.XMLEventConsumer;

import com.sun.xml.internal.fastinfoset.CommonResourceBundle;

allows a user to register a way to allocate events given an XMLStreamReader.
The XMLEventAllocator can be set on an XMLInputFactory
using the property "javax.xml.stream.allocator"
This base class uses EventFactory to create events as recommended in the JavaDoc of XMLEventAllocator.
However, creating new object per each event reduces performance. The implementation of
EventReader therefore will set the Allocator to StAXEventAllocator which implements the
Allocate methods without creating new objects.
The spec for the first Allocate method states that it must NOT modify the state of the Reader
while the second MAY. For consistency, both Allocate methods in this implementation will
NOT modify the state.
/**
 * allows a user to register a way to allocate events given an XMLStreamReader.
 * The XMLEventAllocator can be set on an XMLInputFactory
 * using the property "javax.xml.stream.allocator"
 *
 * This base class uses EventFactory to create events as recommended in the JavaDoc of XMLEventAllocator.
 * However, creating new object per each event reduces performance. The implementation of
 * EventReader therefore will set the Allocator to StAXEventAllocator which implements the
 * Allocate methods without creating new objects.
 *
 * The spec for the first Allocate method states that it must NOT modify the state of the Reader
 * while the second MAY. For consistency, both Allocate methods in this implementation will
 * NOT modify the state.
 *
 */
public class StAXEventAllocatorBase implements XMLEventAllocator {
    XMLEventFactory factory;

    
Creates a new instance of XMLEventAllocator /** Creates a new instance of XMLEventAllocator */
    public StAXEventAllocatorBase() {
        if (System.getProperty("javax.xml.stream.XMLEventFactory")==null) {
            System.setProperty("javax.xml.stream.XMLEventFactory",
                       "com.sun.xml.internal.fastinfoset.stax.factory.StAXEventFactory");
        }
        factory = XMLEventFactory.newInstance();
    }

    // ---------------------methods defined by XMLEventAllocator-----------------//

  
This method creates an instance of the XMLEventAllocator. This
allows the XMLInputFactory to allocate a new instance per reader.
/**
   * This method creates an instance of the XMLEventAllocator. This
   * allows the XMLInputFactory to allocate a new instance per reader.
   */
    public XMLEventAllocator newInstance() {
        return new StAXEventAllocatorBase();
    }

  
This method allocates an event given the current state of the XMLStreamReader.
If this XMLEventAllocator does not have a one-to-one mapping between reader state
and events this method will return null.
Params:
streamReader – The XMLStreamReader to allocate from
Returns:
the event corresponding to the current reader state/**
   * This method allocates an event given the current state of the XMLStreamReader.
   * If this XMLEventAllocator does not have a one-to-one mapping between reader state
   * and events this method will return null.
   * @param streamReader The XMLStreamReader to allocate from
   * @return the event corresponding to the current reader state
   */
    public XMLEvent allocate(XMLStreamReader streamReader) throws XMLStreamException {
        if(streamReader == null )
            throw new XMLStreamException(CommonResourceBundle.getInstance().getString("message.nullReader"));
        return getXMLEvent(streamReader);
    }

  
This method allocates an event or set of events given the current state of
the XMLStreamReader and adds the event or set of events to the consumer that
was passed in.
Params:
streamReader – The XMLStreamReader to allocate from
consumer – The XMLEventConsumer to add to./**
   * This method allocates an event or set of events given the current state of
   * the XMLStreamReader and adds the event or set of events to the consumer that
   * was passed in.
   * @param streamReader The XMLStreamReader to allocate from
   * @param consumer The XMLEventConsumer to add to.
   */
    public void allocate(XMLStreamReader streamReader, XMLEventConsumer consumer) throws XMLStreamException {
        consumer.add(getXMLEvent(streamReader));

    }
    // ---------------------end of methods defined by XMLEventAllocator-----------------//


    XMLEvent getXMLEvent(XMLStreamReader reader){
        XMLEvent event = null;
        //returns the current event
        int eventType = reader.getEventType();
        //this needs to be set before creating events
        factory.setLocation(reader.getLocation());
        switch(eventType){

            case XMLEvent.START_ELEMENT:
            {
                StartElementEvent startElement = (StartElementEvent)factory.createStartElement(reader.getPrefix(),
                                    reader.getNamespaceURI(), reader.getLocalName());

                addAttributes(startElement,reader);
                addNamespaces(startElement, reader);
                //need to fix it along with the Reader
                //setNamespaceContext(startElement,reader);
                event = startElement;
                break;
            }
            case XMLEvent.END_ELEMENT:
            {
                EndElementEvent endElement = (EndElementEvent)factory.createEndElement(
                        reader.getPrefix(), reader.getNamespaceURI(), reader.getLocalName());
                addNamespaces(endElement,reader);
                event = endElement ;
                break;
            }
            case XMLEvent.PROCESSING_INSTRUCTION:
            {
                event = factory.createProcessingInstruction(reader.getPITarget(),reader.getPIData());
                break;
            }
            case XMLEvent.CHARACTERS:
            {
                if (reader.isWhiteSpace())
                  event = factory.createSpace(reader.getText());
                else
                  event = factory.createCharacters(reader.getText());

                break;
            }
            case XMLEvent.COMMENT:
            {
                event = factory.createComment(reader.getText());
                break;
            }
            case XMLEvent.START_DOCUMENT:
            {
                StartDocumentEvent docEvent = (StartDocumentEvent)factory.createStartDocument(
                        reader.getVersion(), reader.getEncoding(), reader.isStandalone());
                if(reader.getCharacterEncodingScheme() != null){
                    docEvent.setDeclaredEncoding(true);
                }else{
                    docEvent.setDeclaredEncoding(false);
                }
                event = docEvent ;
                break;
            }
            case XMLEvent.END_DOCUMENT:{
                EndDocumentEvent endDocumentEvent = new EndDocumentEvent() ;
                event = endDocumentEvent ;
                break;
            }
            case XMLEvent.ENTITY_REFERENCE:{
                event = factory.createEntityReference(reader.getLocalName(),
                        new EntityDeclarationImpl(reader.getLocalName(),reader.getText()));
                break;

            }
            case XMLEvent.ATTRIBUTE:{
                event = null ;
                break;
            }
            case XMLEvent.DTD:{
                event = factory.createDTD(reader.getText());
                break;
            }
            case XMLEvent.CDATA:{
                event = factory.createCData(reader.getText());
                break;
            }
            case XMLEvent.SPACE:{
                event = factory.createSpace(reader.getText());
                break;
            }
        }
        return event ;
    }

    //use event.addAttribute instead of addAttributes to avoid creating another list
    protected void addAttributes(StartElementEvent event,XMLStreamReader streamReader){
        AttributeBase attr = null;
        for(int i=0; i<streamReader.getAttributeCount() ;i++){
            attr = (AttributeBase)factory.createAttribute(streamReader.getAttributeName(i),
                                    streamReader.getAttributeValue(i));
            attr.setAttributeType(streamReader.getAttributeType(i));
            attr.setSpecified(streamReader.isAttributeSpecified(i));
            event.addAttribute(attr);
        }
    }

    //add namespaces to StartElement/EndElement
    protected void addNamespaces(StartElementEvent event,XMLStreamReader streamReader){
        Namespace namespace = null;
        for(int i=0; i<streamReader.getNamespaceCount(); i++){
            namespace = factory.createNamespace(streamReader.getNamespacePrefix(i),
                                streamReader.getNamespaceURI(i));
            event.addNamespace(namespace);
        }
    }
    protected void addNamespaces(EndElementEvent event,XMLStreamReader streamReader){
        Namespace namespace = null;
        for(int i=0; i<streamReader.getNamespaceCount(); i++){
            namespace = factory.createNamespace(streamReader.getNamespacePrefix(i),
                                streamReader.getNamespaceURI(i));
            event.addNamespace(namespace);
        }
    }


}