/*
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.
 *
 *
 */