/*
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.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.util.Calendar;
import java.util.Date;
import java.util.Enumeration;
import java.util.Iterator;

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

/**
 * DateAssociation binds any component that has a set and get Date methods and
 * fire actions events when the date has been changed. Bindings are:
 * <ul>
 * <li>value: a property convertable to/from a date</li>
 * <li>editable: a boolean property that determines whether the user can edit
 * the date in the component</li>
 * <li>enabled: a boolean property that determines whether the component is
 * enabled or disabled</li>
 * </ul>
 *
 * @author rob@yahoo.com
 * @version $Revision: 904 $
 */
public class DateAssociation extends EOAssociation implements ActionListener, FocusListener {
	static final NSArray aspects = new NSArray(new Object[] { ValueAspect, EnabledAspect, EditableAspect });
	static final NSArray aspectSignatures = new NSArray(new Object[] { AttributeToOneAspectSignature,
			AttributeToOneAspectSignature, AttributeToOneAspectSignature });
	static final NSArray objectKeysTaken = new NSArray(new Object[] { "date", "enabled", "editable" });

	private final static NSSelector getDate = new NSSelector("getDate");
	private final static NSSelector setDate = new NSSelector("setDate", new Class[] { Date.class });
	private final static NSSelector addActionListener = new NSSelector("addActionListener",
			new Class[] { ActionListener.class });
	private final static NSSelector removeActionListener = new NSSelector("removeActionListener",
			new Class[] { ActionListener.class });
	private final static NSSelector addFocusListener = new NSSelector("addFocusListener",
			new Class[] { FocusListener.class });
	private final static NSSelector removeFocusListener = new NSSelector("removeFocusListener",
			new Class[] { FocusListener.class });
	private final static NSSelector setEditable = new NSSelector("setEditable", new Class[] { boolean.class });

	// dirty handling
	private boolean needsUpdate;
	private Date nullValue; // placeholder for null value flag

	/**
	 * Constructor specifying the object to be controlled by this association. Does
	 * not establish connection.
	 */
	public DateAssociation(Object anObject) {
		super(anObject);
		needsUpdate = false;
		nullValue = null;
	}

	/**
	 * 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 setDate.implementedByObject(anObject);
	}

	/**
	 * 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 Focus
	 * Listener to the specified object.
	 */
	public void establishConnection() {
		Object component = object();
		try {
			if (addActionListener.implementedByObject(component)) {
				addActionListener.invoke(component, this);
			}
			if (addFocusListener.implementedByObject(component)) {
				addFocusListener.invoke(component, this);
			}
		} catch (Exception exc) {
			throw new WotonomyException("Error while establishing connection", exc);
		}

		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() {
		Object component = object();
		try {
			if (removeActionListener.implementedByObject(component)) {
				removeActionListener.invoke(component, this);
			}
			if (removeFocusListener.implementedByObject(component)) {
				removeFocusListener.invoke(component, this);
			}
		} catch (Exception exc) {
			throw new WotonomyException("Error while breaking connection", exc);
		}
		super.breakConnection();
	}

	/**
	 * Called when either the selection or the contents of an associated display
	 * group have changed.
	 */
	public void subjectChanged() {
		Object component = object();
		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));
			}
			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 date
			try {
				Date dateValue = null;
				// (Date) ValueConverter.convertObjectToClass( value, Date.class );

				if (value instanceof Date) {
					dateValue = (Date) value;
				}

				if ((dateValue == null) && (value instanceof Calendar)) {
					dateValue = ((Calendar) value).getTime();
				}

				if (dateValue == null) {
					// current time (placeholder)
					nullValue = new Date();
					dateValue = nullValue;
				} else {
					nullValue = null;
				}

				if (!dateValue.equals(getDate.invoke(component))) { // No need to update if there is no change.
					setDate.invoke(component, dateValue);
					needsUpdate = false;
				}

			} catch (Exception exc) {
				throw new WotonomyException("Error while updating component connection", exc);
			}
		}

		// 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());
			}
		}

		// editable aspect
		displayGroup = displayGroupForAspect(EditableAspect);
		key = displayGroupKeyForAspect(EditableAspect);
		if (((displayGroup != null) || (key != null)) && (setEditable.implementedByObject(component))) {
			try {
				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) {
					setEditable.invoke(component, converted);
				}
			} catch (Exception exc) {
				throw new WotonomyException("Error while updating component connection (editable aspect)", exc);
			}
		}
	}

	/**
	 * 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() {
		if (!needsUpdate)
			return true;

		EODisplayGroup displayGroup = displayGroupForAspect(ValueAspect);
		if (displayGroup != null) {
			String key = displayGroupKeyForAspect(ValueAspect);
			Object component = object();
			Object value = null;
			try {
				if (getDate.implementedByObject(component)) {
					value = getDate.invoke(component);
				}
				if (nullValue != null) {
					if (nullValue.equals(value)) {
						value = null;
					}
				}
			} catch (Exception exc) {
				throw new WotonomyException("Error updating display group", exc);
			}

			needsUpdate = false;

			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 ActionListener

	/**
	 * Updates object on action performed.
	 */
	public void actionPerformed(ActionEvent evt) {
		needsUpdate = true;
		writeValueToDisplayGroup(); // TODO: Should we do this here or on focus lost?
	}

	// interface FocusListener

	/**
	 * Notifies of beginning of edit.
	 */
	public void focusGained(FocusEvent evt) {
		Object o;
		EODisplayGroup displayGroup;
		Enumeration e = aspects().objectEnumerator();
		while (e.hasMoreElements()) {
			displayGroup = displayGroupForAspect(e.nextElement().toString());
			if (displayGroup != null) {
				displayGroup.associationDidBeginEditing(this);
			}
		}
	}

	/**
	 * Updates object on focus lost and notifies of end of edit.
	 */
	public void focusLost(FocusEvent evt) {
		if (endEditing()) {
			Object o;
			EODisplayGroup displayGroup;
			Enumeration e = aspects().objectEnumerator();
			while (e.hasMoreElements()) {
				displayGroup = displayGroupForAspect(e.nextElement().toString());
				if (displayGroup != null) {
					displayGroup.associationDidEndEditing(this);
				}
			}
		} else {
			// probably should notify of a validation error here,
			// but how to also handle actionPerformed without copying code?
			/*
			 * Object value = null; try { if ( getText.implementedByObject( object() ) ) {
			 * value = getText.invoke( object() ); } } catch ( Exception exc ) { throw new
			 * WotonomyException( "Error updating display group", exc ); }
			 * 
			 * EODisplayGroup displayGroup = displayGroupForAspect( ValueAspect ); String
			 * key = displayGroupKeyForAspect( ValueAspect ); if ( displayGroup != null ) {
			 * if ( displayGroup.associationFailedToValidateValue( this, (String) value,
			 * key, object(), "That format was not recognized." ) ) { new
			 * net.wotonomy.ui.swing.util.StackTraceInspector(); } if ( object() instanceof
			 * Component ) { ((Component)object()).requestFocus(); } }
			 */
		}
	}
}

/*
 * $Log$ 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 1.7 2004/01/28 18:34:57 mpowers Better handling for enabling. Now
 * respecting enabledToSetSelectedObjectValueForKey from display group.
 *
 * Revision 1.6 2003/08/06 23:07:52 chochos general code cleanup (mostly,
 * removing unused imports)
 *
 * Revision 1.5 2001/07/30 16:32:55 mpowers Implemented support for
 * bulk-editing. Detail associations will now apply changes to all selected
 * objects.
 *
 * Revision 1.4 2001/02/17 17:23:49 mpowers More changes to support compiling
 * with jdk1.1 collections.
 *
 * Revision 1.3 2001/02/17 16:52:05 mpowers Changes in imports to support
 * building with jdk1.1 collections.
 *
 * Revision 1.2 2001/01/17 16:25:26 mpowers Now catching null values from data
 * object.
 *
 * Revision 1.1 2001/01/10 22:26:32 mpowers Contributing DateAssociation.
 *
 * Revision 1.1 2001/01/10 21:30:27 rglista Initial checkin
 *
 *
 */