/*
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.util.Iterator;

import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

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

/**
* SliderAssociation binds a JSlider component to
* a display group.  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 SliderAssociation extends EOAssociation
	implements ChangeListener
{
    static final NSArray aspects = 
        new NSArray( new Object[] {
            ValueAspect, EnabledAspect, VisibleAspect
        } );
    static final NSArray aspectSignatures = 
        new NSArray( new Object[] {
            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 SliderAssociation ( 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 JSlider );
    }
    
    /**
    * 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().addChangeListener( 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().removeChangeListener( this );
        super.breakConnection();
    }

    /**
    * Called when either the selection or the contents 
    * of an associated display group have changed.
    */
    public void subjectChanged ()
    {
		JSlider component = component();
		EODisplayGroup displayGroup;
		String key;
		Object value;
	
		// value aspect
		displayGroup = displayGroupForAspect( ValueAspect );
		if ( displayGroup != null )
		{
			key = displayGroupKeyForAspect( ValueAspect );
            component.setEnabled( 
                    displayGroup.enabledToSetSelectedObjectValueForKey( key ) );
                    
                    if ( displayGroup.selectedObjects().size() > 1 )
                    {
                        // if there're more than one object selected, set
                        // the value to blank for all of them.
                        Object previousValue;

                        Iterator indexIterator = displayGroup.selectionIndexes().
                                                  iterator();

                        // get value for the first selected object.
                        int initialIndex = ( (Integer)indexIterator.next() ).intValue();
                        previousValue = displayGroup.valueForObjectAtIndex(
                                                  initialIndex, key );
                        value = null;

                        // go through the rest of the selected objects, compare each
                        // value with the previous one. continue comparing if two
                        // values are equal, break the while loop if they're different.
                        // the final value will be the common value of all selected objects
                        // if there is one, or be blank if there is not.
                        while ( indexIterator.hasNext() )
                        {
                            int index = ( (Integer)indexIterator.next() ).intValue();
                            Object currentValue = displayGroup.valueForObjectAtIndex(
                                                  index, key );
                            if ( currentValue != null && !currentValue.equals( previousValue ) )
                            {
                                value = null;
                                break;
                            }
                            else
                            {
                                // currentValue is the same as the previous one
                                value = currentValue;
                            }

                        } // end while

                    } else {

                        value = displayGroup.selectedObjectValueForKey( key );
                    } // end checking size of displayGroup

			// 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().removeChangeListener( this );
				component.setValue( intValue );
                component().addChangeListener( this );
			}
		}

		// enabled aspect
		displayGroup = displayGroupForAspect( EnabledAspect );
		key = displayGroupKeyForAspect( EnabledAspect );
		if ( ( displayGroup != null ) || ( key != null ) )
		{
			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.isEnabled() )
            {
                component.setEnabled( converted.booleanValue() );	
            }
		}

		// visible aspect
		displayGroup = displayGroupForAspect( VisibleAspect );
		key = displayGroupKeyForAspect( VisibleAspect );
		if ( ( displayGroup != null ) || ( key != null ) )
		{
			if ( displayGroup != null )
			{
				value =
					displayGroup.selectedObjectValueForKey( key );
			}
			else
			{
				// treat bound key without display group as a value
				value = key;	
			}
			Boolean converted = (Boolean)
				ValueConverter.convertObjectToClass( 
					value, Boolean.class );
					
			if ( converted != null )
			{
				if ( converted.booleanValue() != component.isVisible() )
				{
					component.setVisible( 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() );

            boolean returnValue = true;
            Iterator selectedIterator = displayGroup.selectionIndexes().iterator();
            while ( selectedIterator.hasNext() )
            {
                int index = ( (Integer)selectedIterator.next() ).intValue();

                if ( !displayGroup.setValueForObjectAtIndex( value, index, key ) )
                {
                    returnValue = false;
                }
            }
            return returnValue;
		}
		return false;
	}

    // interface ChangeListener
	
	/**
	* Updates object on change.
	*/
	public void stateChanged(ChangeEvent e)  
	{
		writeValueToDisplayGroup();
	}
    
	private JSlider component()
	{
		return (JSlider) 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 1.8  2004/01/28 18:34:57  mpowers
 * Better handling for enabling.
 * Now respecting enabledToSetSelectedObjectValueForKey from display group.
 *
 * Revision 1.7  2003/08/06 23:07:52  chochos
 * general code cleanup (mostly, removing unused imports)
 *
 * Revision 1.6  2002/10/11 20:12:58  mpowers
 * Updated aspect signature.
 *
 * Revision 1.5  2002/10/11 20:08:14  mpowers
 * Added visible aspect to slider association.
 *
 * Revision 1.4  2001/11/01 15:54:37  mpowers
 * Minor update to aspect signature.
 *
 * Revision 1.3  2001/07/30 16:32:55  mpowers
 * Implemented support for bulk-editing.  Detail associations will now
 * apply changes to all selected objects.
 *
 * Revision 1.2  2001/02/16 15:03:34  mpowers
 * Fixed: slider sets value in display group after selection changed.
 *
 * Revision 1.1.1.1  2000/12/21 15:48:55  mpowers
 * Contributing wotonomy.
 *
 * Revision 1.2  2000/12/20 16:25:41  michael
 * Added log to all files.
 *
 *
 */