/*
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.
 *
 *
 */