/*
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.Adjustable;
import java.awt.Component;
import java.awt.event.AdjustmentEvent;
import java.awt.event.AdjustmentListener;

import net.wotonomy.foundation.NSArray;
import net.wotonomy.foundation.internal.ValueConverter;
import net.wotonomy.ui.EOAssociation;
import net.wotonomy.ui.EODisplayGroup;

/**
* AdjustableAssociation binds any Adjustable component to
* a display group.  Components implementing the adjustable
* interface include: ScrollBar and JScrollBar.
* Bindings are: 
* <ul>
* <li>value: a property convertable to/from a string</li> 
* <li>enabled: a boolean property that determines whether
* the user can select the text in the field</li> 
* </ul>
*
* @author michael@mpowers.net
* @author $Author: cgruber $
* @version $Revision: 904 $
*/
public class AdjustableAssociation extends EOAssociation
	implements AdjustmentListener
{
    static final NSArray aspects = 
        new NSArray( new Object[] {
            ValueAspect, EnabledAspect
        } );
    static final NSArray aspectSignatures = 
        new NSArray( new Object[] {
            AttributeToOneAspectSignature, 
			AttributeToOneAspectSignature, 
			AttributeToOneAspectSignature,
			AttributeToOneAspectSignature 
        } );
    static final NSArray objectKeysTaken = 
        new NSArray( new Object[] {
            "value" 
        } );
		
    /**
    * Constructor specifying the object to be controlled by this
    * association.  Does not establish connection.
    */
    public AdjustableAssociation ( 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 ( anObject instanceof Adjustable );
    }
    
    /**
    * 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.  This is typically "value" or somesuch.
    */
    public static String primaryAspect ()
    {
        return ValueAspect;
    }
        
    /**
    * 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.  This implementation 
	* attempts to add this class as an ActionListener
	* and as a FocusListener to the specified object.
    */
    public void establishConnection ()
    {
		component().addAdjustmentListener( this );
        super.establishConnection();
		
		// forces update from bindings
		subjectChanged();
    }
	
    /**
    * Breaks the connection between this association and 
    * its object.  Override to stop listening for events
    * from the object.
    */
    public void breakConnection ()
    {
		component().removeAdjustmentListener( this );
        super.breakConnection();
    }

    /**
    * Called when either the selection or the contents 
    * of an associated display group have changed.
    */
    public void subjectChanged ()
    {
		Adjustable component = component();
		EODisplayGroup displayGroup;
		String key;
		Object value;
	
		// value aspect
		displayGroup = displayGroupForAspect( ValueAspect );
		if ( displayGroup != null )
		{
			key = displayGroupKeyForAspect( ValueAspect );
            if ( component instanceof Component )
            {
                ((Component)component).setEnabled( 
                        displayGroup.enabledToSetSelectedObjectValueForKey( key ) );
            }
			value = displayGroup.selectedObjectValueForKey( key );
			
			// convert value to int
			value = ValueConverter.convertObjectToClass( 
				value, Integer.class );

			int intValue;
			if ( value == null ) 
			{
				intValue = 0;
			}
			else
			{
				intValue = ((Integer)value).intValue();
			}
			
			if ( component.getValue() != intValue )
			{
				component.setValue( intValue );
			}
		}

		// enabled aspect
		displayGroup = displayGroupForAspect( EnabledAspect );
		key = displayGroupKeyForAspect( EnabledAspect );
		if ( ( ( displayGroup != null ) || ( key != null ) )
		&& ( component instanceof Component ) )
		{
			if ( displayGroup != null )
			{
				value =
					displayGroup.selectedObjectValueForKey( key );
			}
			else
			{
				// treat bound key without display group as a value
				value = 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() );	
            }
		}

    }
	
    /**
    * Forces this association to cause the object to 
    * stop editing and validate the user's input.
    * @return false if there were problems validating,
    * or true to continue.
    */
    public boolean endEditing ()
    {
		return writeValueToDisplayGroup();
    }
	
	/**
	* Writes the value currently in the component
	* to the selected object in the display group
	* bound to the value aspect.
    * @return false if there were problems validating,
    * or true to continue.
	*/
	protected boolean writeValueToDisplayGroup()
	{
		EODisplayGroup displayGroup = 
			displayGroupForAspect( ValueAspect );
		if ( displayGroup != null )
		{
			String key = displayGroupKeyForAspect( ValueAspect );
			Object value = new Integer( component().getValue() );
			return displayGroup.setSelectedObjectValue( value, key );
		}
		return false;
	}

    // interface AdjustmentListener
	
	/**
	* Updates object on action performed.
	*/
	public void adjustmentValueChanged(AdjustmentEvent e) 
	{
		writeValueToDisplayGroup();
	}
    
	private Adjustable component()
	{
		return (Adjustable) object();	
	}
}

/*
 * $Log$
 * Revision 1.2  2006/02/18 23:19:05  cgruber
 * Update imports and maven dependencies.
 *
 * Revision 1.1  2006/02/16 13:22:23  cgruber
 * Check in all sources in eclipse-friendly maven-enabled packages.
 *
 * Revision 1.3  2004/01/28 18:34:57  mpowers
 * Better handling for enabling.
 * Now respecting enabledToSetSelectedObjectValueForKey from display group.
 *
 * Revision 1.2  2003/08/06 23:07:52  chochos
 * general code cleanup (mostly, removing unused imports)
 *
 * Revision 1.1.1.1  2000/12/21 15:48:35  mpowers
 * Contributing wotonomy.
 *
 * Revision 1.2  2000/12/20 16:25:40  michael
 * Added log to all files.
 *
 *
 */