/*
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.event.ActionEvent;
import java.awt.event.ActionListener;

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

/**
* RadioPanelAssociation binds RadioButtonPanels to
* display groups.  It works exactly like a 
* ComboBoxAssociation.  Bindings are: 
* <ul>
*
* <li>value: a property of the selected object in the 
* display group that will be bind to the item the user
* selects or the text that the user enters in the field.</li> 
*
* <li>titles: a property of the objects in the bound 
* display group that will appear in the list.  If the
* objects aspect is not bound, this property is also
* used to populate the value binding.</li> 
*
* <li>objects: optional - if specified, when the user 
* selects an title in the list, the property of the
* object at the corresponding index of the bound display
* group will be used to populate the value binding.</li> 
*
* <li>enabled: a boolean property of the selected object in the 
* display group that determines whether
* the user can edit the field.</li> 
* 
* </ul>
*
* @author michael@mpowers.net
* @author $Author: cgruber $
* @version $Revision: 904 $
*/
public class RadioPanelAssociation extends EOAssociation
	implements ActionListener
{
    static final NSArray aspects = 
        new NSArray( new Object[] {
            TitlesAspect, ValueAspect,
			ObjectsAspect, EnabledAspect
        } );
    static final NSArray aspectSignatures = 
        new NSArray( new Object[] {
            AttributeToOneAspectSignature, 
            AttributeToOneAspectSignature, 
			AttributeToOneAspectSignature, 
			AttributeToOneAspectSignature 
        } );
    static final NSArray objectKeysTaken = 
        new NSArray( new Object[] {
            "text" 
        } );
		
   /**
    * Constructor specifying the object to be controlled by this
    * association.  Does not establish connection.
    */
    public RadioPanelAssociation ( 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 RadioButtonPanel );
    }
    
    /**
    * 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.  Subclasses should begin
    * listening for events from their controlled object here.
    */
    public void establishConnection ()
    {
		super.establishConnection();

		// prepopulate titles
		EODisplayGroup displayGroup = 
			displayGroupForAspect( TitlesAspect );
		if ( displayGroup != null )
		{
			String key = displayGroupKeyForAspect( TitlesAspect );
			populateTitles( displayGroup, key );
		}
        populateValue();
        addAsListener();
    }
	
	protected void addAsListener()
	{
		component().addActionListener( this );
	}
    
    /**
    * Breaks the connection between this association and 
    * its object.  Override to stop listening for events
    * from the object.
    */
    public void breakConnection ()
    {
		removeAsListener();
        super.breakConnection();
    }

	protected void removeAsListener()
	{
		component().removeActionListener( this );
	}
	
    /**
    * Called when either the selection or the contents 
    * of an associated display group have changed.
    */
    public void subjectChanged ()
    {
		removeAsListener();
		
		RadioButtonPanel component = component();
		EODisplayGroup displayGroup;
		String key;
	
		// titles aspect
		displayGroup = displayGroupForAspect( TitlesAspect );
		if ( displayGroup != null )
		{
			// if backing group has changed
			if ( displayGroup.contentsChanged() ) 
			{
				key = displayGroupKeyForAspect( TitlesAspect );
				populateTitles( displayGroup, key );
			}
		}

        // value aspect
        populateValue();
        
		// enabled aspect
		displayGroup = displayGroupForAspect( EnabledAspect );
		if ( displayGroup != null )
		{
			key = displayGroupKeyForAspect( EnabledAspect );
			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.isEnabled() )
            {
                component.setEnabled( converted.booleanValue() );	
            }
		}
		
		addAsListener();
    }
		
	/**
	* Called to repopulate the title list from the
	* specified display group.
	*/
	protected void populateTitles( 
		EODisplayGroup displayGroup, String key )
	{
		Object value;
		int count = displayGroup.displayedObjects().count();
		String[] titles = new String[ count ];
		for ( int i = 0; i < count; i++ )
		{
			value = displayGroup.valueForObjectAtIndex( i, key );
			if ( value != null )
			{
				titles[i] = value.toString();
			}
			else
			{
				titles[i] = "";	
			}
		}
		component().setLabels( titles );
	}
    
	/**
	* Called to populate the value from the display group.
	*/
	protected void populateValue()
	{
		RadioButtonPanel component = component();
		EODisplayGroup displayGroup;
		String key;

		// value aspect
		displayGroup = displayGroupForAspect( ValueAspect );
		if ( displayGroup != null )
		{
			key = displayGroupKeyForAspect( ValueAspect );
            component.setEnabled( 
                    displayGroup.enabledToSetSelectedObjectValueForKey( key ) );
                    
			Object value = displayGroup.selectedObjectValueForKey( key );

			// objects aspect
			EODisplayGroup objectsDisplayGroup = 
				displayGroupForAspect( ObjectsAspect );
			if ( ( objectsDisplayGroup != null ) && ( value != null ) )
			{
				String objectKey = displayGroupKeyForAspect( ObjectsAspect );
				Object match;
				int index = NSArray.NotFound;
				int count = objectsDisplayGroup.displayedObjects().count();
				for ( int i = 0; i < count; i++ )
				{
					match = objectsDisplayGroup.valueForObjectAtIndex( i, objectKey );
					if ( value.equals( match ) )
					{
						index = i;
					}
				}
				if ( index == NSArray.NotFound )
				{
					if ( component.getValue() != null )
					{	
						component.setValue( null );
					}
				}
				else
				{
					String[] titles = component().getLabels();
					component.setValue( titles[ index ] );
				}
			}
			else
			{
				if ( value != null ) value = value.toString();
				component.setValue( (String) value );
			}
		}
	}
    
    /**
    * 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()
	{
		RadioButtonPanel component = component();
		EODisplayGroup displayGroup;
		String key;
		
		// selected title aspect
		displayGroup = displayGroupForAspect( ValueAspect );
		if ( displayGroup != null )
		{
			key = displayGroupKeyForAspect( ValueAspect );
			Object value = null;

			// selected object aspect, if any
			EODisplayGroup objectsGroup = 
				displayGroupForAspect( ObjectsAspect );
			if ( objectsGroup != null )
			{
				String objectKey = displayGroupKeyForAspect( ObjectsAspect );
				String selectedValue = component.getValue();				
				if ( selectedValue != null )
				{
					String[] titles = component.getLabels();
					int index = -1;
					for ( int i = 0; i < titles.length; i++ )
					{
						if ( selectedValue.equals( titles[i] ) )
						{
							index = i;	
						}
					}
					if ( index != -1 )
					{
						value = objectsGroup
							.valueForObjectAtIndex( index, objectKey );				
					}
				}
			}
			else // just use the selected item
			{
				value = component.getValue();	
			}

			return displayGroup.setSelectedObjectValue( value, key );
		}
		
		return false;
	}
        
    // interface ActionListener
	
	/**
	* Updates object on action performed.
	*/
	public void actionPerformed( ActionEvent evt )
	{
		writeValueToDisplayGroup();
	}
    	
	// convenience

	private RadioButtonPanel component() 
	{
		return (RadioButtonPanel) object();
	}
}

/*
 * $Log$
 * Revision 1.2  2006/02/18 23:19:05  cgruber
 * Update imports and maven dependencies.
 *
 * Revision 1.1  2006/02/16 13:22:22  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  2001/02/16 17:48:07  mpowers
 * Populating titles or data not longer marks target object as changed.
 *
 * Revision 1.1.1.1  2000/12/21 15:48:52  mpowers
 * Contributing wotonomy.
 *
 * Revision 1.3  2000/12/20 16:25:41  michael
 * Added log to all files.
 *
 *
 */