001    /*
002     * Copyright 2004-2005 Stephen J. McConnell.
003     *
004     * Licensed  under the  Apache License,  Version 2.0  (the "License");
005     * you may not use  this file  except in  compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     *   http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed  under the  License is distributed on an "AS IS" BASIS,
012     * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
013     * implied.
014     *
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    
019    package net.dpml.station;
020    
021    import java.rmi.Remote;
022    import java.rmi.RemoteException;
023    
024    import net.dpml.component.Component;
025    
026    import net.dpml.lang.PID;
027    
028    /**
029     * The Callback interface defines a service provider to a process through
030     * which the process may issue notification of state change.
031     *
032     * @author <a href="http://www.dpml.net">Digital Product Meta Library</a>
033     * @version 1.2.0
034     */
035    public interface Callback extends Remote
036    {
037       /**
038        * Method invoked by a process to signal that the process has started.
039        *
040        * @param pid the process identifier
041        * @param handler optional handler reference
042        * @exception RemoteException if a remote error occurs
043        */
044        void started( PID pid, Component handler ) throws RemoteException;
045        
046       /**
047        * Method invoked by a process to signal that the process has 
048        * encounter an error condition.
049        *
050        * @param throwable the error condition
051        * @param fatal if true the process is requesting termination
052        * @exception RemoteException if a remote error occurs
053        */
054        void error( Throwable throwable, boolean fatal ) throws RemoteException;
055        
056       /**
057        * Method invoked by a process to send a arbitary message to the 
058        * the callback handler.
059        *
060        * @param message the message
061        * @exception RemoteException if a remote error occurs
062        */
063        void info( String message ) throws RemoteException;
064        
065       /**
066        * Method invoked by a process to signal its imminent termination.
067        *
068        * @exception RemoteException if a remote error occurs
069        */
070        void stopped() throws RemoteException;
071        
072    }
073