org.polymap.core.project.ui.util.SelectionAdapter.java Source code

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Here is the source code for org.polymap.core.project.ui.util.SelectionAdapter.java

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/* 
 * polymap.org
 * Copyright 2013, Falko Brutigam. All rights reserved.
 *
 * This 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; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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 org.polymap.core.project.ui.util;

import java.util.Iterator;

import com.google.common.collect.Iterables;
import com.google.common.collect.Iterators;

import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;

/**
 * Helps to handle {@link IStructuredSelection}. This adapter filters the given
 * {@link IStructuredSelection} for elements with the given type <code>T</code>.
 * 
 * @author <a href="http://www.polymap.de">Falko Brutigam</a>
 */
public class SelectionAdapter implements Iterable {

    public static SelectionAdapter on(ISelection delegate) {
        return new SelectionAdapter(delegate);
    }

    // instance *******************************************

    private IStructuredSelection delegate;

    public SelectionAdapter(ISelection delegate) {
        this.delegate = delegate instanceof IStructuredSelection ? (IStructuredSelection) delegate
                : new StructuredSelection();
    }

    @Override
    public Iterator iterator() {
        return delegate.toList().iterator();
    }

    public <T> Iterator<T> iterator(Class<T> type) {
        return Iterators.filter(iterator(), type);
    }

    public Object first() {
        Iterator it = iterator();
        return it.hasNext() ? it.next() : null;
    }

    public <T> T first(Class<T> type) {
        Iterator<T> it = iterator(type);
        return it.hasNext() ? it.next() : null;
    }

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

    public <T> int size(Class<T> type) {
        return Iterables.size(elementsOfType(type));
    }

    public <T> Iterable<T> elementsOfType(Class<T> type) {
        return Iterables.filter(this, type);
    }
}