/*
   Wotonomy: OpenStep design patterns for pure Java applications.
   Copyright (C) 2000 Intersect Software Corporation
   
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.
   
  This library 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
  Lesser General Public License for more details.
  
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, see http://www.gnu.org
  */
  
  package net.wotonomy.ui.swing;
  
  import java.awt.Component;
  import java.awt.event.ActionEvent;
  import java.awt.event.ActionListener;
  import java.util.Enumeration;
  
  import net.wotonomy.foundation.NSArray;
  import net.wotonomy.foundation.NSSelector;
  import net.wotonomy.foundation.internal.ValueConverter;
  import net.wotonomy.foundation.internal.WotonomyException;
  import net.wotonomy.ui.EOAssociation;
  import net.wotonomy.ui.EODisplayGroup;
  
  /***
  * ActionAssociation binds any ActionEvent broadcaster 
  * (typically Buttons and the like) to a display group.  
  * Actions are invoked on all selected objects in the 
  * display group bound to the action aspect.
  * Bindings are: 
  * <ul>
  * <li>action: a method to be invoked on selected objects.
  * If the argument aspect is bound, the method must take 
  * one argument.  Otherwise, the method must take no arguments.</li> 
  * <li>argument: the attribute of the selected object(s) (possibly 
  * from a different display group) that will be used as an argument 
  * to the action method</li> 
  * <li>enabled: a boolean property that determines whether
  * the controlled component is enabled</li> 
  * <li>visible: a boolean property that determines whether
  * the controlled component is visible</li> 
  * </ul>
  *
  * @author michael@mpowers.net
  * @author $Author: cgruber $
  * @version $Revision: 904 $
  */
  public class ActionAssociation extends EOAssociation
  	implements ActionListener
  {
      static final NSArray aspects = 
          new NSArray( new Object[] {
              ActionAspect, ArgumentAspect, EnabledAspect, VisibleAspect
          } );
      static final NSArray aspectSignatures = 
          new NSArray( new Object[] {
              AttributeToOneAspectSignature, 
  			AttributeToOneAspectSignature, 
  			AttributeToOneAspectSignature, 
  			AttributeToOneAspectSignature 
          } );
      static final NSArray objectKeysTaken = 
          new NSArray( new Object[] {
              "target" 
          } );
  		
  	static NSSelector addActionListener =
  		new NSSelector( "addActionListener", 
  		new Class[] { ActionListener.class } );
  	static NSSelector removeActionListener =
  		new NSSelector( "removeActionListener", 
  		new Class[] { ActionListener.class } );
  
      /***
      * Constructor specifying the object to be controlled by this
      * association.  Does not establish connection.
      */
      public ActionAssociation ( Object anObject )
      {
          super( anObject );
      }
      
      /***
      * Returns a List of aspect signatures whose contents
      * correspond with the aspects list.  Each element is 
      * a string whose characters represent a capability of
      * the corresponding aspect. <ul>
      * <li>"A" attribute: the aspect can be bound to
      * an attribute.</li>
      * <li>"1" to-one: the aspect can be bound to a
      * property that returns a single object.</li>
     * <li>"M" to-one: the aspect can be bound to a
     * property that returns multiple objects.</li>
     * </ul> 
     * An empty signature "" means that the aspect can
     * bind without needing a key.
     * This implementation returns "A1M" for each
     * element in the aspects array.
     */
     public static NSArray aspectSignatures ()
     {
         return aspectSignatures;
     }
     
     /***
     * Returns a List that describes the aspects supported
     * by this class.  Each element in the list is the string
     * name of the aspect.  This implementation returns an
     * empty list.
     */
     public static NSArray aspects ()
     {
         return aspects;
     }
     
     /***
     * Returns a List of EOAssociation subclasses that,
     * for the objects that are usable for this association,
     * are less suitable than this association.
     */
     public static NSArray associationClassesSuperseded ()
     {
         return new NSArray();
     }
     
     /***
     * Returns whether this class can control the specified 
     * object. 
     */
     public static boolean isUsableWithObject ( Object anObject )
     {
         return 
 		   ( addActionListener.implementedByObject( anObject ) )
 		&& ( removeActionListener.implementedByObject( anObject ) );
     }
     
     /***
     * Returns a List of properties of the controlled object
     * that are controlled by this class.  For example,
     * "stringValue", or "selected".
     */
     public static NSArray objectKeysTaken ()
     {
         return objectKeysTaken;
     }
     
     /***
     * Returns the aspect that is considered primary
     * or default.  
     */
     public static String primaryAspect ()
     {
         return ActionAspect;
     }
         
     /***
     * Returns whether this association can bind to the
     * specified display group on the specified key for
     * the specified aspect.  
     */
     public boolean canBindAspect ( 
         String anAspect, EODisplayGroup aDisplayGroup, String aKey)
     {
         return ( aspects.containsObject( anAspect ) );
     }
     
     /***
     * Establishes a connection between this association
     * and the controlled object.  Subclasses should begin
     * listening for events from their controlled object here.
     */
     public void establishConnection ()
     {
 		try
 		{
 			addActionListener.invoke( object(), this );
 		}
 		catch ( Exception exc )
 		{
 			throw new WotonomyException( "EOActionAssociation: " +
 				"could not add action listener to object:" + object() );
 		}
         super.establishConnection();
     }
     
     /***
     * Breaks the connection between this association and 
     * its object.  Override to stop listening for events
     * from the object.
     */
     public void breakConnection ()
     {
 		try
 		{
 			removeActionListener.invoke( object(), this );
 		}
 		catch ( Exception exc )
 		{
 			throw new WotonomyException( "EOActionAssociation: " +
 				"could not add action listener to object:" + object() );
 		}
         super.breakConnection();
     }
     
     /***
     * Called when either the selection or the contents 
     * of an associated display group have changed.
     * This implementation does nothing.
     */
     public void subjectChanged ()
     {
 		Object component = object();
 		EODisplayGroup displayGroup;
 		String key;
 	
 		if ( component instanceof Component ) 
 		{
 			// enabled aspect
 			displayGroup = displayGroupForAspect( EnabledAspect );
 			if ( displayGroup != null )
 			{
 				key = displayGroupKeyForAspect( EnabledAspect );
                 ((Component)component).setEnabled( 
                         displayGroup.enabledToSetSelectedObjectValueForKey( key ) );
 				Object value = 
 					displayGroup.selectedObjectValueForKey( key );
                 Boolean converted = null;
                 if ( value != null ) 
                 {
                     converted = (Boolean)
                         ValueConverter.convertObjectToClass(
                             value, Boolean.class );
                 }
                 if ( converted == null ) converted = Boolean.FALSE;
                 if ( converted.booleanValue() != 
                     ((Component)component).isEnabled() )
                 {
                     ((Component)component).setEnabled( 
                         converted.booleanValue() );	
                 }
 			}
 	
 			// visible aspect
 			displayGroup = displayGroupForAspect( VisibleAspect );
 			if ( displayGroup != null )
 			{
 				key = displayGroupKeyForAspect( VisibleAspect );
 				Object value = 
 					displayGroup.selectedObjectValueForKey( key );
 				Boolean converted = (Boolean)
 					ValueConverter.convertObjectToClass( 
 						value, Boolean.class );
 				if ( converted != null )
 				{
 					if ( converted.booleanValue() != 
 						((Component)component).isVisible() )
 					{
 						((Component)component).setVisible( 
 							converted.booleanValue() );	
 					}
 				}			
 			}
 		}
     }
             
     // interface ActionListener
     
     public void actionPerformed( ActionEvent evt )
     {
 		EODisplayGroup actionDisplayGroup = null;
 		String actionKey = null;
 		
 		// action aspect
 		actionDisplayGroup = displayGroupForAspect( ActionAspect );
 		if ( actionDisplayGroup != null )
 		{
 			actionKey = displayGroupKeyForAspect( ActionAspect );
 
 			//TODO: argument aspect not implemented
 
 			try
 			{
 			
 				NSSelector selector = new NSSelector( actionKey );		
 				Enumeration e = 
 					actionDisplayGroup.selectedObjects().objectEnumerator();
 				while ( e.hasMoreElements() )
 				{
 					selector.invoke( e.nextElement() );
 				}
 			}
 			catch ( Exception exc )
 			{
 				throw new WotonomyException( 
 					"ActionAssociation: error invoking action: " + actionKey, exc );
 			}
 		}
 	}	
 }
 
 /*
  * $Log$
  * Revision 1.2  2006/02/18 23:19:05  cgruber
  * Update imports and maven dependencies.
  *
  * Revision 1.1  2006/02/16 13:22:22  cgruber
  * Check in all sources in eclipse-friendly maven-enabled packages.
  *
  * Revision 1.4  2004/01/28 18:34:57  mpowers
  * Better handling for enabling.
  * Now respecting enabledToSetSelectedObjectValueForKey from display group.
  *
  * Revision 1.3  2003/08/06 23:07:52  chochos
  * general code cleanup (mostly, removing unused imports)
  *
  * Revision 1.2  2001/02/17 16:52:05  mpowers
  * Changes in imports to support building with jdk1.1 collections.
  *
  * Revision 1.1.1.1  2000/12/21 15:48:28  mpowers
  * Contributing wotonomy.
  *
  * Revision 1.5  2000/12/20 16:25:40  michael
  * Added log to all files.
  *
  *
  */