Provider.java

/**
 * Copyright (c) 2014-2017 by the respective copyright holders.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.eclipse.smarthome.core.common.registry;

import java.util.Collection;

/**
 * A {@link Provider} provides elements of a determined type and the subinterfaces
 * are registered as OSGi services. Providers are tracked by {@link Registry} services, which collect all elements from
 * different providers of the same
 * type.
 *
 * @author Dennis Nobel - Initial contribution
 *
 * @param <E>
 *            type of the provided elements
 */
public interface Provider<E> {

    /**
     * Adds a {@link ProviderChangeListener} which must be notified if there are
     * changes concerning the elements provided by the {@link Provider}.
     *
     * @param listener
     *            the listener to be added
     */
    void addProviderChangeListener(ProviderChangeListener<E> listener);

    /**
     * Returns a collection of all elements.
     *
     * @return collection of all elements
     */
    Collection<E> getAll();

    /**
     * Removes a {@link ProviderChangeListener}.
     *
     * @param listener
     *            the listener to be removed.
     */
    void removeProviderChangeListener(ProviderChangeListener<E> listener);

}