net.refractions.udig.ui.FeatureCollectionSelection.java Source code

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Here is the source code for net.refractions.udig.ui.FeatureCollectionSelection.java

Source

/* uDig - User Friendly Desktop Internet GIS client
 * http://udig.refractions.net
 * (C) 2004, Refractions Research Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License.
 *
 * This library 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
 * Lesser General Public License for more details.
 */
package net.refractions.udig.ui;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.NoSuchElementException;

import org.eclipse.jface.viewers.IStructuredSelection;
import org.geotools.feature.FeatureCollection;
import org.geotools.feature.FeatureIterator;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;

/**
 * Adapt a feature collection as a Selection so it can be used with StructedViewers.
 * 
 * @author Jesse
 * @since 1.1.0
 */
public class FeatureCollectionSelection implements IStructuredSelection, IBlockingSelection {
    Collection<Iterator> openIterators = new ArrayList<Iterator>();
    FeatureCollection<SimpleFeatureType, SimpleFeature> wrapped;
    private volatile SimpleFeature firstElement;

    public FeatureCollectionSelection(FeatureCollection<SimpleFeatureType, SimpleFeature> selectedFeatures) {
        this.wrapped = selectedFeatures;
    }

    @Override
    protected void finalize() throws Throwable {
        for (Iterator iterator : openIterators) {
            wrapped.close(iterator);
        }
        super.finalize();
    }

    public Object getFirstElement() {
        if (isEmpty())
            throw new NoSuchElementException("SimpleFeature Collection is empty, there is no first element"); //$NON-NLS-1$
        if (firstElement == null) {
            synchronized (this) {
                if (firstElement == null) {
                    FeatureIterator<SimpleFeature> iter = wrapped.features();
                    try {
                        firstElement = iter.next();
                    } finally {
                        iter.close();
                    }
                }
            }
        }
        return firstElement;
    }

    public Iterator iterator() {
        Iterator iter = wrapped.iterator();
        openIterators.add(iter);
        return iter;
    }

    public int size() {
        return wrapped.size();
    }

    public Object[] toArray() {
        return toList().toArray();
    }

    @SuppressWarnings("unchecked")
    public List toList() {
        if (wrapped instanceof List)
            return (List) wrapped;
        LinkedList arrayList = new LinkedList();
        Iterator iter = wrapped.iterator();
        try {
            while (iter.hasNext()) {
                arrayList.add(iter.next());
            }
        } finally {
            wrapped.close(iter);
        }
        return arrayList;
    }

    public boolean isEmpty() {
        return wrapped.isEmpty();
    }

}