/*
 * Created on Jun 29, 2006 10:16:26 PM
 * Copyright (C) 2006 Aelitis, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program 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 General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * AELITIS, SAS au capital de 46,603.30 euros
 * 8 Allee Lenotre, La Grille Royale, 78600 Le Mesnil le Roi, France.
 */
package com.aelitis.azureus.ui.swt.browser.msg;

import com.aelitis.azureus.core.messenger.ClientMessageContext;

/**
 * Accepts and handles messages dispatched from {@link MessageDispatcher}.
 * Subclasses should use the message's operation ID and parameters to perform
 * the requested operation.
 * 
 * @author dharkness
 * @created Jul 18, 2006
 */
public abstract class AbstractMessageListener implements MessageListener
{
    protected ClientMessageContext context = null;
    
    private String id;


    /**
     * Stores the given context for accessing the browser and its services.
     * 
     * @param context used to access the browser
     */
    public AbstractMessageListener ( String id ) {
        this.id = id;
    }


    /**
     * Returns the unique ID for this listener.
     * 
     * @return listener's unique ID
     */
    public String getId ( ) {
        return id;
    }

    /**
     * Returns the context for this listener.
     * 
     * @return listener's context
     */
    public ClientMessageContext getContext ( ) {
        return context;
    }

    /**
     * Sets the context for this listener. Called by its dispatcher when attached.
     * 
     * @param context the new context for this listener
     */
    public void setContext ( ClientMessageContext context ) {
        if ( this.context == null ) {
            this.context = context;
        }
    }

    /**
     * Handles the given message, usually by parsing the parameters 
     * and calling the appropriate operation.
     * 
     * @param message holds all message information
     */
    public abstract void handleMessage ( BrowserMessage message ) ;


    /**
     * Displays a debug message tagged with the listener ID.
     * 
     * @param message sent to the debug log
     */
    protected void debug ( String message ) {
        context.debug("[" + id + "] " + message);
    }

    /**
     * Displays a debug message and exception tagged with the listener ID.
     * 
     * @param message sent to the debug log
     * @param t exception to log with message
     */
    public void debug ( String message , Throwable t ) {
        context.debug("[" + id + "] " + message, t);
    }
}