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   /*
    Copyright (c) 2003, Laurent Caillette.
    All rights reserved.
   
    Redistribution and use in source and binary forms, with or without modifica-
    tion, are permitted provided that the following conditions are met:
   
    1. Redistributions of  source code must  retain the above copyright  notice,
       this list of conditions and the following disclaimer.
  
   2. Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
      and/or other materials provided with the distribution.
  
   3. The end-user documentation included with the redistribution, if any, must
      include  the following  acknowledgment:  "This product includes  software
      written by Laurent Caillette."
      Alternately, this  acknowledgment may  appear in the software itself,  if
      and wherever such third-party acknowledgments normally appear.
  
   4. The name "Laurent Caillette" must  not  be used to  endorse or
       promote  products derived from  this software without
      prior written permission. For written permission, please contact
      laurent.caillette@laposte.net
  
   5. Products  derived from this software may not  be called
      "Laurent Caillette", nor may "Laurent Caillette" appear
      in their name,  without prior written permission  of the
      author.
  
   THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
   INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
   FITNESS  FOR A PARTICULAR  PURPOSE ARE  DISCLAIMED.  IN NO  EVENT SHALL  THE
   AUTHOR (LAURENT CAILLETTE) BE LIABLE FOR  ANY DIRECT, INDIRECT, INCIDENTAL,
   SPECIAL,  EXEMPLARY, OR CONSEQUENTIAL  DAMAGES (INCLUDING, BUT NOT LIMITED
   TO, PROCUREMENT  OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
   OR  PROFITS; OR BUSINESS  INTERRUPTION)  HOWEVER CAUSED AND ON ANY
   THEORY OF LIABILITY,  WHETHER  IN CONTRACT,  STRICT LIABILITY,  OR TORT
   (INCLUDING  NEGLIGENCE OR  OTHERWISE) ARISING IN  ANY WAY OUT OF THE  USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package tweed.context;
  import org.apache.avalon.framework.logger.AbstractLogEnabled;
  import org.apache.avalon.framework.logger.Logger;
  import tweed.action.ActionPerformer;
  import tweed.binding.InputValidationHub;
  import tweed.invocation.CommandInvoker;
  import tweed.system.Instantiator;
  import tweed.system.bus.EventBus;
  
  /***
   * Creates {@link Context} objects.
   *
   * @see ContextPatcher for modifying already-instantiated <code>Context</code>
   *     objects.
   * @author Laurent Caillette
   * @version $Id$
   */
  public class DefaultContextFactory extends AbstractLogEnabled {
  
  // ==================
  // Some configurators
  // ==================
  
    private boolean serverSide = false ;
  
    public void setServerSide( boolean serverSide ) {
      this.serverSide = serverSide ;
    }
  
    private final static String CONTEXTLOGGERCHILD_DEFAULTNAME = "context" ;
  
    public void enableLogging( Logger logger ) {
      if( logger == null ) {
        throw new IllegalArgumentException( "logger == null" ) ;
      }
      super.enableLogging( logger ) ;
      if( contextLogger == null ) {
        contextLogger = logger.getChildLogger( CONTEXTLOGGERCHILD_DEFAULTNAME ) ;
      }
    }
  
    private Logger contextLogger = null ;
  
    public void setContextLogger( Logger contextLogger ) {
      if( contextLogger == null ) {
        throw new IllegalArgumentException( "contextLogger == null" ) ;
      }
      this.contextLogger = contextLogger;
    }
  
    private Instantiator commandInvokerInstantiator = new Instantiator(
        CommandInvoker.class,
        new Class[] { Context.class }
    ) ;
  
    public void setCommandInvokerClass( Class commandInvokerClass ) {
      if( commandInvokerClass == null ) {
        throw new IllegalArgumentException( "commandInvokerClass == null" ) ;
     }
     commandInvokerInstantiator.setConcreteClassQuiet( commandInvokerClass ) ;
   }
 
   private DefaultContext context = null ;
 
 // ==================
 // The factory method
 // ==================
 
   public Context createContext() {
 
     if( contextLogger == null ) {
       String msg = "Logger was not set" ;
       getLogger().error( msg ); ;
       throw new IllegalStateException( msg ) ;
     }
 
     context = instantiateContext() ;
 
     context.setLogger( contextLogger ) ;
     context.setServerSide( serverSide ) ;
 
     if( serverSide ) {
       // TODO: fail if client-side only members were set
     } else {
       configureClientSideContext( context ) ;
     }
 
     getLogger().info(
         "Created and configured an instance of " +
         context.getClass().getName()
     ) ;
 
     return context ;
   }
 
   protected DefaultContext instantiateContext() {
     return new DefaultContext() ;
   }
 
   private void configureClientSideContext( DefaultContext context ) {
     CommandInvoker invoker = instantiateCommandInvoker( context ) ;
     context.setInvoker( invoker ) ;
     context.initializeClientSide() ;
     context.setActionPerformer( new ActionPerformer( context ) ) ;
     context.setValidationHub( new InputValidationHub( context ) ) ;
   }
 
   protected CommandInvoker instantiateCommandInvoker( Context context ) {
     CommandInvoker invoker = ( CommandInvoker )
         commandInvokerInstantiator.instantiateQuiet( context ) ;
     return invoker ;
   }
 
 
 // ====================
 // The concrete Context
 // ====================
 
   /***
    * A mutable <code>Context</code> which should not be instantiated
    * from outside the enclosing class or its derivates.
    */
   protected class DefaultContext implements Context {
 
     private CommandInvoker invoker ;
     private EventBus eventBus ;
 
     public Context getContext() {
       return this ;
     }
 
     public CommandInvoker getInvoker() {
       return invoker ;
     }
 
     public void setInvoker( CommandInvoker invoker ) {
       this.invoker = invoker ;
     }
 
     private boolean serverSide = false ;
 
     public boolean isClientSide() {
       return ! serverSide ;
     }
 
     public boolean isServerSide() {
       return serverSide ;
     }
 
     public void setServerSide( boolean serverSide ) {
       this.serverSide = serverSide ;
     }
 
     private Logger logger = null ;
 
     public Logger getLogger() {
       return logger ;
     }
 
     public void setLogger( Logger logger ) {
       this.logger = logger ;
     }
 
     private InputValidationHub validationHub = null ;
 
     public InputValidationHub getInputValidationHub() {
       return validationHub;
     }
 
     public void setValidationHub( InputValidationHub validationHub ) {
       this.validationHub = validationHub;
     }
 
     public EventBus getBus() {
       return eventBus ;
     }
 
     private ActionPerformer actionPerformer ;
 
     public ActionPerformer getActionPerformer() {
       return actionPerformer;
     }
 
     public void setActionPerformer( ActionPerformer actionPerformer ) {
       this.actionPerformer = actionPerformer;
     }
 
     protected void initializeClientSide() {
       eventBus = new EventBus( this ) ;
 
     }
 
 
   }
 
 }