package org.apache.maven.wagon.events;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.
   */
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * The class allows registration and removal of event listeners of type
   * TransferListener and dispatch of those events to those listeners
   *
   * @author <a href="michal.maczka@dimatics.com">Michal Maczka</a>
   *
   */
  public final class TransferEventSupport
  {
  
      /**
       * registered listeners
       */
      private final List<TransferListener> listeners = new ArrayList<TransferListener>();
  
      /**
       * Adds the listener to the collection of listeners
       * who will be notified when any transfer event occurs
       * in this <code>Wagon</code> object.
       * <br/>
       * If listener is <code>null</code>, no exception is thrown and no action is performed
       *
       * @param listener the transfer listener
       * @see #removeTransferListener(org.apache.maven.wagon.events.TransferListener)
       * @see TransferListener
       */
      public synchronized void addTransferListener( final TransferListener listener )
      {
          if ( listener != null )
          {
              listeners.add( listener );
          }
      }
  
      /**
       * Removes the transfer listener from the collection of listeners so
       * it no longer receives transfer events.
       * <br/>
       * If listener is <code>null</code> or specified listener was not added
       * to this <code>TransferEventSupport</code> object
       * no exception is thrown and no action is performed
       *
       * @param listener the transfer listener
       * @see #addTransferListener(TransferListener)
       */
      public synchronized void removeTransferListener( final TransferListener listener )
      {
          listeners.remove( listener );
      }
  
      /**
       * Returns whether the specified instance of transfer
       * listener was added to the collection of listeners
       * who will be notified when an transfer event occurs
       *
       * @param listener the transfer listener
       * @return <code>true<code>
       *         if given listener was added to the collection of listeners
       *         <code>false</code> otherwise
       * @see org.apache.maven.wagon.events.TransferEvent
       * @see #addTransferListener(TransferListener)
       */
      public synchronized boolean hasTransferListener( final TransferListener listener )
      {
          return listeners.contains( listener );
      }
  
  
      /**
       * Dispatches the given <code>TransferEvent</code>
       * to all registered listeners (calls method {@link TransferListener#transferStarted(TransferEvent)} on all of
       * them}. The Event should be of type {@link TransferEvent#TRANSFER_COMPLETED}
       *
       * @param transferEvent the TransferEvent which will be dispatched to listeners
       */
     public synchronized void fireTransferStarted( final TransferEvent transferEvent )
     {
         for ( TransferListener listener : listeners )
         {
             listener.transferStarted( transferEvent );
         }
     }
 
     /**
      * Dispatches the given <code>TransferEvent</code>
      * to all registered listeners (calls method {@link TransferListener#transferProgress(TransferEvent, byte[], int)}
      * on all of them). The Event should be of type {@link TransferEvent#TRANSFER_PROGRESS}.
      *
      * @param transferEvent the TransferEvent which will be dispatched to listeners
      * @param buffer        the buffer containing the additional content
      * @param length        the length of the content in the buffer
      */
     public synchronized void fireTransferProgress( final TransferEvent transferEvent, byte[] buffer, int length )
     {
         for ( TransferListener listener : listeners )
         {
             listener.transferProgress( transferEvent, buffer, length );
 
         }
     }
 
     /**
      * Dispatches the given <code>TransferEvent</code>
      * to all registered listeners (calls method {@link TransferListener#transferCompleted(TransferEvent)} on all of
      * them}. The Event should be of type {@link TransferEvent#TRANSFER_COMPLETED}
      *
      * @param transferEvent the TransferEvent which will be dispatched to listeners
      */
     public synchronized void fireTransferCompleted( final TransferEvent transferEvent )
     {
         for ( TransferListener listener : listeners )
         {
             listener.transferCompleted( transferEvent );
 
         }
     }
 
     /**
      * Dispatches the given <code>TransferEvent</code>
      * to all registered listeners (calls method {@link TransferListener#transferError(TransferEvent)}  on all of them.
      * The Event should be of type {@link TransferEvent#TRANSFER_ERROR} and it is expected that
      * {@link TransferEvent#getException()} } method will return not null value
      *
      * @param transferEvent the TransferEvent which will be dispatched to listeners
      */
     public synchronized void fireTransferError( final TransferEvent transferEvent )
     {
         for ( TransferListener listener : listeners )
         {
             listener.transferError( transferEvent );
 
         }
     }
 
     /**
      * Dispatches the given debug message
      * to all registered listeners (calls method {@link TransferListener#debug(String)} on all of them.
      *
      * @param message the debug message which will be dispatched to listeners
      */
     public synchronized void fireDebug( final String message )
     {
 
         for ( TransferListener listener : listeners )
         {
             listener.debug( message );
 
         }
     }
 
     /**
      * Dispatches the given <code>TransferEvent</code>
      * to all registered listeners (calls method {@link TransferListener#transferInitiated(TransferEvent)} on all of
      * them. The Event should be of type {@link TransferEvent#TRANSFER_INITIATED}.
      *
      * @param transferEvent the TransferEvent which will be dispatched to listeners
      */
     public synchronized void fireTransferInitiated( final TransferEvent transferEvent )
     {
         for ( TransferListener listener : listeners )
         {
             listener.transferInitiated( transferEvent );
         }
     }
 }