path: root/projects/net.wotonomy.ui.swing/src/main/java/net/wotonomy/ui/swing/ButtonAssociation.java

/*
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.util.Iterator;

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

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;

/**
 * ButtonAssociation binds any component that uses a ButtonModel (all Swing
 * button classes) to a display group. This association should be used to handle
 * individual JRadioButtons and JCheckBoxes. Bindings are:
 * <ul>
 * <li>value: a boolean property that determines the selected state of the
 * button model. This will set the value for radio buttons and check boxes.</li>
 * <li>enabled: a boolean property that determines the enabled state of the
 * button model.</li>
 * <li>visible: a boolean property that determines the visible state of the
 * button model.</li>
 * </ul>
 *
 * @author michael@mpowers.net
 * @author $Author: cgruber $
 * @version $Revision: 904 $
 */
public class ButtonAssociation 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, AttributeToOneAspectSignature });
	static final NSArray objectKeysTaken = new NSArray(new Object[] { "model.selected" });

	static NSSelector getModel = new NSSelector("getModel", new Class[] {});

	protected ButtonModel buttonModel;
	protected boolean lastKnownValue;

	/**
	 * Constructor specifying the object to be controlled by this association. Does
	 * not establish connection. This implementation expects a ButtonModel or a
	 * class that has a "getModel" method that returns a ButtonModel.
	 */
	public ButtonAssociation(Object anObject) {
		super(anObject);

		if (anObject instanceof ButtonModel) {
			buttonModel = (ButtonModel) anObject;
		} else {
			try {
				buttonModel = (ButtonModel) getModel.invoke(anObject);
			} catch (Exception exc) {
				throw new WotonomyException(
						"EOButtonAssociation: " + "could not retrieve a button model from object:" + 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. This
	 * implementation expects a ButtonModel or a class that has a "getModel" method
	 * that returns a ButtonModel.
	 */
	public static boolean isUsableWithObject(Object anObject) {
		return (anObject instanceof ButtonModel) || (getModel.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.
	 */
	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() {
		buttonModel.addChangeListener(this);
		super.establishConnection();
		subjectChanged();
	}

	/**
	 * Breaks the connection between this association and its object. Override to
	 * stop listening for events from the object.
	 */
	public void breakConnection() {
		buttonModel.removeChangeListener(this);
		super.breakConnection();
	}

	/**
	 * Called when either the selection or the contents of an associated display
	 * group have changed. This implementation does nothing.
	 */
	public void subjectChanged() {
		Object component = object();
		EODisplayGroup displayGroup;
		String key;

		// value aspect
		displayGroup = displayGroupForAspect(ValueAspect);

		if (displayGroup != null) {
			key = displayGroupKeyForAspect(ValueAspect);
			if (component instanceof Component) {
				((Component) component).setEnabled(displayGroup.enabledToSetSelectedObjectValueForKey(key));
			}

			Object value;
			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 // displayGroup has only one object
			{
				value = displayGroup.selectedObjectValueForKey(key);
			} // end checking size of displayGroup

			buttonModel.setArmed(false);
			buttonModel.setPressed(false);

			if (value != null) {
				Boolean converted = (Boolean) ValueConverter.convertObjectToClass(value, Boolean.class);
				if (converted != null) {
					lastKnownValue = converted.booleanValue();
					if (converted.booleanValue() != buttonModel.isSelected()) {
						buttonModel.removeChangeListener(this);
						buttonModel.setSelected(converted.booleanValue());
						buttonModel.addChangeListener(this);
					}
				} // end checking converted == null
			} else {
				buttonModel.setArmed(true);
				buttonModel.setPressed(true);
			}
		}

		// 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() != buttonModel.isEnabled()) {
				buttonModel.removeChangeListener(this);
				buttonModel.setEnabled(converted.booleanValue());
				buttonModel.addChangeListener(this);
			}
		}

		// visible aspect
		displayGroup = displayGroupForAspect(VisibleAspect);
		if (displayGroup != null) {
			key = displayGroupKeyForAspect(VisibleAspect);
			Object value = displayGroup.selectedObjectValueForKey(key);
			Boolean converted = (Boolean) ValueConverter.convertObjectToClass(value, Boolean.class);
			if (converted != null) {
				if (converted.booleanValue() != ((Component) component).isVisible()) {
					((Component) component).setVisible(converted.booleanValue());
				}
			}
		}
	}

	/**
	 * 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) {
			boolean returnValue = true;
			String key = displayGroupKeyForAspect(ValueAspect);
			Object value = new Boolean(buttonModel.isSelected());

			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

	public void stateChanged(ChangeEvent e) {
		if (buttonModel.isSelected() != lastKnownValue) {
			lastKnownValue = buttonModel.isSelected();
			writeValueToDisplayGroup();
		}
	}

}

/*
 * $Log$ 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 2001/07/30 16:32:55 mpowers Implemented support for
 * bulk-editing. Detail associations will now apply changes to all selected
 * objects.
 *
 * Revision 1.5 2001/06/29 22:28:19 mpowers Tabs to spaces.
 *
 * Revision 1.4 2001/06/29 22:17:31 mpowers Now updating the component on
 * establishConnection.
 *
 * Revision 1.3 2001/02/27 02:10:38 mpowers No longer updating values to the
 * display group if the value has not changed.
 *
 * Revision 1.2 2001/02/21 20:33:01 mpowers Fixed bug with change listener.
 *
 * Revision 1.1.1.1 2000/12/21 15:48:38 mpowers Contributing wotonomy.
 *
 * Revision 1.3 2000/12/20 16:25:40 michael Added log to all files.
 *
 *
 */