Copyright Microsoft Corporation
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
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/**
 * Copyright Microsoft Corporation
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.microsoft.azure.storage;

import java.util.concurrent.CopyOnWriteArrayList;

Represents a generic event multi-caster that allows event listeners to be dynamically added and removed.
Type parameters:
<EVENT_TYPE> – 
           An object that represents the type of the event.
<EVENT_LISTENER_TYPE> – 
           An object that represents the type of the event listener./**
 * Represents a generic event multi-caster that allows event listeners to be dynamically added and removed.
 * 
 * @param <EVENT_TYPE>
 *            An object that represents the type of the event.
 * @param <EVENT_LISTENER_TYPE>
 *            An object that represents the type of the event listener.
 */
public final class StorageEventMultiCaster<EVENT_TYPE extends BaseEvent, EVENT_LISTENER_TYPE extends StorageEvent<EVENT_TYPE>> {

    
Holds the list of listeners.
/**
     * Holds the list of listeners.
     */
    private final CopyOnWriteArrayList<EVENT_LISTENER_TYPE> listeners = new CopyOnWriteArrayList<EVENT_LISTENER_TYPE>();

    
Adds a listener to the event chain.
Params:
listener – 
           An EventListenerType object that represents the listener to add./**
     * Adds a listener to the event chain.
     * 
     * @param listener
     *            An <code>EventListenerType</code> object that represents the listener to add.
     */
    public void addListener(final EVENT_LISTENER_TYPE listener) {
        this.listeners.add(listener);
    }

    
Fires the event to all subscribed event listeners.
Params:
event – 
           An EVENTTYPEobject that represents the event being multi-casted./**
     * Fires the event to all subscribed event listeners.
     * 
     * @param event
     *            An <code>EVENTTYPE</code>object that represents the event being multi-casted.
     */
    public void fireEvent(final EVENT_TYPE event) {
        for (final StorageEvent<EVENT_TYPE> listener : this.listeners) {
            listener.eventOccurred(event);
        }
    }

    
Returns a value that indicates whether any event listeners are registered for events.
Returns:
true if any event listeners are registered; otherwise, false./**
     * Returns a value that indicates whether any event listeners are registered for events.
     * 
     * @return <code>true</code> if any event listeners are registered; otherwise, <code>false</code>.
     */
    public boolean hasListeners() {
        return this.listeners.size() > 0;
    }

    
Removes an event listener from the event chain.
Params:
listener – 
           An EventListenerType object that represents the listener to remove./**
     * Removes an event listener from the event chain.
     * 
     * @param listener
     *            An <code>EventListenerType</code> object that represents the listener to remove.
     */
    public void removeListener(final EVENT_LISTENER_TYPE listener) {
        this.listeners.remove(listener);
    }
}