org.xmlpull.infoset.impl.XmlElementWithViewsImpl Maven / Gradle / Ivy

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/* -*-             c-basic-offset: 4; indent-tabs-mode: nil; -*-  //------100-columns-wide------>|*/
// for license please see accompanying LICENSE.txt file (available also at http://www.xmlpull.org/)

package org.xmlpull.infoset.impl;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import org.xmlpull.infoset.XmlBuilderException;
import org.xmlpull.infoset.XmlElement;
import org.xmlpull.infoset.XmlElementView;
import org.xmlpull.infoset.XmlNamespace;

/**
 * This class supoprts for views to XML Infoset Element.
 *
 * @version $Revision: 1.4 $
 * @author Aleksander Slominski
 */
public class XmlElementWithViewsImpl extends XmlElementImpl implements XmlElement {
    private List views = null;
    
    public XmlElementWithViewsImpl clone() throws CloneNotSupportedException {
        XmlElementWithViewsImpl cloned = (XmlElementWithViewsImpl) super.clone();
        cloned.views = null;
        return cloned;
    }
        
    public XmlElementWithViewsImpl(XmlNamespace namespace, String name) {
        super(namespace, name);
    }
    
    public XmlElementWithViewsImpl(String namespaceName, String name) {
        super(namespaceName, name);
    }
    
    public XmlElement newElement(String namespace, String name) {
        return new XmlElementWithViewsImpl(namespace, name);
    }
    
    public XmlElement newElement(XmlNamespace namespace, String name) {
        return new XmlElementWithViewsImpl(namespace, name);
    }
    
    public  T viewAs(Class someViewClass) throws XmlBuilderException {
        //public XmlElementView viewAs(Class someViewClass) throws XmlBuilderException {
        if (views != null) {
            for (int i = 0; i < views.size(); i++) {
                XmlElementView view = views.get(i);
                Class viewClass = view.getClass();
                if (someViewClass.isAssignableFrom(viewClass)) {
                    //return (XmlElementView) view;
                    return (T) view;
                }
            }
        }
        try {
            XmlElementView view = (XmlElementView)
                someViewClass.getConstructor(new Class[]{XmlElement.class}).newInstance(
                new Object[]{this});
            addView(view);
            return (T) view;
        } catch (Exception e) {
            throw new XmlBuilderException("could not create view to " + someViewClass, e);
        }
        
        
    }
    
    public void addView(XmlElementView newView) throws XmlBuilderException {
        Class newViewClass = newView.getClass();
        if (views != null) {
            for (int i = 0; i < views.size(); i++) {
                XmlElementView view = views.get(i);
                Class viewClass = view.getClass();
                if (newViewClass.isAssignableFrom(viewClass)) {
                    //return (XmlElementView) view;
                    if (newView == view) {
                        return; //view may have added itself in constructor ...
                    } else {
                        throw new XmlBuilderException(
                            "there is already view that is assignable to " + newViewClass
                            + "(old: " + view + " new: " + newView + ")");
                    }
                }
            }
        }
        if (views == null) {
            views = new LinkedList();
        }
        views.add(newView);
    }
    
    public  Iterable elements(XmlNamespace n, String name,
                                                           Class someViewClass)
    {
        final Iterable iterable = elements(n, name);
        return new XmlViewIterableAdapter(iterable, someViewClass);
    }
    
}

// thansk to broken generics T.class have to duplicate instead of
class XmlViewIterableAdapter implements Iterable {
    private final Iterable iterable;
    private final Class xmlViewClass;
    
    XmlViewIterableAdapter(Iterable iterable, Class xmlViewClass) {
        this.iterable = iterable;
        this.xmlViewClass = xmlViewClass;
    }
    
    public T next(Iterator iter) {
        //return (T) iter.next();
        XmlElement el = (XmlElement) iter.next();
        return el.viewAs(xmlViewClass); //BROKENJAVA: T.class would be simpleter ...
    }
    
    public Iterator iterator() {
        final Iterator iter = iterable.iterator();
        return new Iterator() {
            
            public boolean hasNext() {
                return iter.hasNext();
            }
            
            public void remove() {
                iter.remove();
            }
            
            public T next() {
                return XmlViewIterableAdapter.this.next(iter);
            }
        };
    }
}