path: root/projects/net.wotonomy.ui.swing/src/main/java/net/wotonomy/ui/swing/TimedTextAssociation.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.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.net.URL;
import java.text.Format;
import java.text.ParseException;
import java.util.Enumeration;
import java.util.Iterator;

import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JOptionPane;
import javax.swing.JTextArea;
import javax.swing.LookAndFeel;
import javax.swing.Timer;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.Document;
import javax.swing.text.JTextComponent;

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;

/**
* TimedTextAssociation works like TextAssociation,
* but instead of using a delayed event to update the
* model, it uses a timer so that the model is only
* updated if the user pauses typing for some short interval.
* This is useful when the update and/or re-read of the model
* is a costly operation.
* Bindings are:
* <ul>
* <li>value: a property convertable to/from a string</li>
* <li>editable: a boolean property that determines whether
* the user can edit the text in the field</li>
* <li>enabled: a boolean property that determines whether
* the user can select the text in the field</li>
* <li>label: a boolean property that determines whether
* field should appear as a read-only, selectable label</li>
* <li>icon: a property that returns a Swing icon, for use
* with JLabels and other components with setIcon() methods.
* If bound to a static string, the string will be used to
* load an image resource from the selected object's class.</li>
* </ul>
*
* @author michael@mpowers.net
* @author $Author: cgruber $
* @version $Revision: 904 $
*/
public class TimedTextAssociation extends EOAssociation
	implements FocusListener, ActionListener, DocumentListener
{
    //TODO: need to refactor this so that it can subclass text association.
    //This implementation is basically a branch from the v1.20 TextAssociation.
    
    static final NSArray aspects =
        new NSArray( new Object[] {
            ValueAspect, EnabledAspect, EditableAspect, LabelAspect, IconAspect
        } );
    static final NSArray aspectSignatures =
        new NSArray( new Object[] {
            AttributeToOneAspectSignature,
			AttributeToOneAspectSignature,
			AttributeToOneAspectSignature,
			AttributeToOneAspectSignature
        } );
    static final NSArray objectKeysTaken =
        new NSArray( new Object[] {
            "text", "enabled", "editable"
        } );

	private final static NSSelector getText =
		new NSSelector( "getText" );
	private final static NSSelector setText =
		new NSSelector( "setText",
		new Class[] { String.class } );
	private final static NSSelector getDocument =
		new NSSelector( "getDocument" );
	private final static NSSelector setIcon =
		new NSSelector( "setIcon",
		new Class[] { Icon.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 } );

	// null handling
	protected boolean wasNull;
	protected static final String EMPTY_STRING = "";

	// dirty handling
	protected boolean needsUpdate;
	protected boolean hasDocument;
    protected boolean isListening;

	// formatting
	protected Format format;

    // cache the value aspect
    private EODisplayGroup valueDisplayGroup;
    private String valueKey;

    // coalescing document events
    protected boolean autoUpdating;
    protected int interval = 400; // adjust as needed
    protected Timer keyTimer;

    // NOTE: a new key timer is created for each use and
    // is disposed when the timer is stopped.
    // Swing's Timer class is kept in a static list of timers
    // and each retains a strong reference to their listeners.
    // This caused a memory leak as associations typically
    // refer to their controlled component which is referred
    // to by its parents and so on until no application window
    // will ever get garbage collected.  yikes.

    /**
    * Constructor specifying the object to be controlled by this
    * association.  Does not establish connection.
    */
    public TimedTextAssociation ( Object anObject )
    {
        super( anObject );
		wasNull = false;
		needsUpdate = false;
		hasDocument = false;
        isListening = true;
        valueDisplayGroup = null;
        valueKey = null;

        autoUpdating = true;
        keyTimer = 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 setText.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 ) );
    }

    /**
    * Binds the specified aspect of this association to the
    * specified key on the specified display group.
    */
    public void bindAspect (
        String anAspect, EODisplayGroup aDisplayGroup, String aKey )
	{
		if ( ValueAspect.equals( anAspect ) )
		{
			valueDisplayGroup = aDisplayGroup;
			valueKey = aKey;
		}
		super.bindAspect( anAspect, aDisplayGroup, aKey );
	}

    /**
    * 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 ()
    {
		Object component = object();
		try
		{
			if ( addActionListener.implementedByObject( component ) )
			{
				addActionListener.invoke( component, this );
			}
			if ( addFocusListener.implementedByObject( component ) )
			{
				addFocusListener.invoke( component, this );
			}
            hasDocument = false;
			if ( getDocument.implementedByObject( component ) )
			{
				Object document = getDocument.invoke( component );
                if ( document instanceof Document )
                {
                    ((Document)document).addDocumentListener( this );
                    hasDocument = true;
                }
			}
		}
		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 );
			}
			if ( getDocument.implementedByObject( component ) )
			{
				Object document = getDocument.invoke( component );
                if ( document instanceof Document )
                {
                    ((Document)document).removeDocumentListener( 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 = valueDisplayGroup;
		if ( displayGroup != null )
		{
            if ( component instanceof Component )
            {
                ((Component)component).setEnabled( 
                    displayGroup.enabledToSetSelectedObjectValueForKey( valueKey ) );
            }
            
			key = valueKey;

                        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 {

                            // if there's only one object selected.
                            value = displayGroup.selectedObjectValueForKey( key );
                       } // end checking the size of selected objects in displayGroup

                        // convert value to string
                        if ( value == null )
                        {
                                wasNull = true;
                                value = EMPTY_STRING;
                        }
                        else
                        {
                                wasNull = false;
                                if ( format() != null )
                                {
                                        try
                                        {
                                                value = format().format( value );
                                        }
                                        catch ( IllegalArgumentException exc )
                                        {
                                                value = value.toString();
                                        }
                                }
                        }


			try
			{
                            if ( ! value.toString().equals( getText.invoke( component ) ) )
                            {
                                // No need to listen for any events that might get fired
                                // while setting the text since we are the one setting it.
                                boolean wasListening = isListening;
                                isListening = false;

                                // setText is an expensive operation
                                setText.invoke( component, value.toString() );

                                isListening = wasListening;
                                needsUpdate = false;
                            }
			}
			catch ( Exception exc )
			{
				throw new WotonomyException(
					"Error while updating component connection", exc );
			}
		}

		// icon aspect
		displayGroup = displayGroupForAspect( IconAspect );
		key = displayGroupKeyForAspect( IconAspect );
		if ( key != null )
		{
			if ( displayGroup != null )
			{
				value =
					displayGroup.selectedObjectValueForKey( key );
			}
			else
			{
                            // treat bound key without display group
                            // as a resource to be loaded from the selected class.
                            value = null;
                            Object o = displayGroup.selectedObject();
                            if ( o != null )
                            {
                                URL url = o.getClass().getResource( key );
                                if ( url != null )
                                {
                                    value = new ImageIcon( url );
                                }
                            }
			}

			try
			{
                setIcon.invoke( component, value );
			}
			catch ( Exception exc )
			{
				throw new WotonomyException(
					"Error while updating component connection", exc );
			}
		}

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

		// editable aspect
		displayGroup = displayGroupForAspect( EditableAspect );
		key = displayGroupKeyForAspect( EditableAspect );
		if ( ( key != null )
		&& ( component instanceof JTextComponent ) )
		{
			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() != ((JTextComponent)component).isEditable() )
				{
					((JTextComponent)component).setEditable( converted.booleanValue() );
				}
			}
		}

		// label aspect
		displayGroup = displayGroupForAspect( LabelAspect );
		key = displayGroupKeyForAspect( LabelAspect );

		if ( ( key != null )
		&& ( component instanceof JTextComponent ) )
		{
			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() )
				{
                                        if ( component instanceof JTextComponent )
                                        {
                                            if ( component instanceof JTextArea )
                                            {
                                                areaToLabel( (JTextArea) component );
                                            }
                                            else
                                            {
                                                fieldToLabel( (JTextComponent) component );
                                            }
                                        }
				}
				else
				{
                                        if ( component instanceof JTextComponent )
                                        {
                                            if ( component instanceof JTextArea )
                                            {
                                                labelToArea( (JTextArea) component );
                                            }
                                            else
                                            {
                                                labelToField( (JTextComponent ) component );
                                            }
                                        }
                                }
			}
		}

    }

    private void fieldToLabel( JTextComponent aTextField )
    {
        // turn on wrapping and disable editing and highlighting

        aTextField.setEditable(false);
        aTextField.setOpaque(false);

        // Set the border, colors and font to that of a label

        LookAndFeel.installBorder(aTextField, "Label.border");

        LookAndFeel.installColorsAndFont(aTextField,
            "Label.background",
            "Label.foreground",
            "Label.font");
    }

    private void labelToField( JTextComponent aTextField )
    {
        // turn on wrapping and disable editing and highlighting

        aTextField.setEditable(true);
        aTextField.setOpaque(true);

        // Set the border, colors and font to that of a label

        LookAndFeel.installBorder(aTextField, "TextField.border");

        LookAndFeel.installColorsAndFont(aTextField,
            "TextField.background",
            "TextField.foreground",
            "TextField.font");
    }

	private void areaToLabel( JTextArea aTextArea )
	{
            // turn on wrapping and disable editing and highlighting

            aTextArea.setLineWrap(true);
            aTextArea.setWrapStyleWord(true);
            aTextArea.setEditable(false);

            // Set the text area's border, colors and font to
            // that of a label

            LookAndFeel.installBorder(aTextArea, "Label.border");

            LookAndFeel.installColorsAndFont(aTextArea,
                "Label.background",
                "Label.foreground",
                "Label.font");

	}

	private void labelToArea( JTextArea aTextArea )
	{
            // turn on wrapping and disable editing and highlighting

            aTextArea.setEditable(true);

            // Set the border, colors and font to that of a label

            LookAndFeel.installBorder(aTextArea, "TextArea.border");

            LookAndFeel.installColorsAndFont(aTextArea,
                "TextArea.background",
                "TextArea.foreground",
                "TextArea.font");
	}


    /**
    * 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 ()
    {
        if ( keyTimer != null )
        {
            keyTimer.stop();
            keyTimer.removeActionListener( this );
            keyTimer = null;
        }
		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()
	{
            boolean returnValue = true;
            if ( hasDocument && !needsUpdate ) return true;

            EODisplayGroup displayGroup = valueDisplayGroup;
            if ( displayGroup != null )
            {
                String key = valueKey;
                Object component = object();
                Object value = null;
                try
                {
                        //if ( getText.implementedByObject( component ) )
                        //{
                                value = getText.invoke( component );
                        //}
                }
                catch ( Exception exc )
                {
                        throw new WotonomyException(
                                "Error updating display group", exc );
                }

                if ( ( wasNull ) && ( EMPTY_STRING.equals( value ) ) )
                {
                        value = null;
                }
                else
                if ( format() != null )
                {
                    try
                    {
                        value = format().parseObject( value.toString() );
                    }
                    catch ( ParseException exc )
                    {
                        String message = exc.getMessage();
                        //"That format was not recognized.";
                        if ( displayGroup.associationFailedToValidateValue(
                                this, value.toString(), key, exc, message ) )
                        {
                            boolean wasListening = isListening;
                            isListening = false;
                            JOptionPane.showMessageDialog(
                                (Component)component, message );
                            isListening = wasListening;
                        }
                        needsUpdate = false;
                        return false;
                    }
                }

                needsUpdate = false;

                // only update if the value is different from the one in the display group
                Object existingValue = displayGroup.selectedObjectValueForKey( key );
                if ( displayGroup.selectedObjects().size() == 1 )
                {
                    if ( existingValue == value ) return true;
                    if ( ( existingValue != null ) && ( existingValue.equals( value ) ) ) return true;
                    if ( ( value != null ) && ( value.equals( existingValue ) ) ) return true;
                }

                // we might lose focus if display group displays a validation message
                boolean wasListening = isListening;
                isListening = false;

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

                    if ( displayGroup.setValueForObjectAtIndex( value, index, key ) )
                    {
                        isListening = wasListening;
                        needsUpdate = false;
                    }
                    else
                    {
                        isListening = wasListening;
                        needsUpdate = false;
                        returnValue = false;
                    }
                }

            }
            return returnValue;
	}

	/**
	* Sets the Format that is used to convert values from the display
	* group to and from text that is displayed in the component.
    * Having a formatter disables auto-updating.
	*/
	public void setFormat( Format aFormat )
	{
		format = aFormat;
	}

	/**
	* Gets the Format that is used to convert values from the display
	* group to and from text that is displayed in the component.
	*/
	public Format format()
	{
		return format;
	}

    // interface ActionListener

	/**
	* Updates object on action performed.
	*/
	public void actionPerformed( ActionEvent evt )
	{
        if ( keyTimer != null )
        {
            keyTimer.stop();
            keyTimer.removeActionListener( this );
            keyTimer = null;
        }
        if ( ! isListening ) return;
        if ( needsUpdate )
        {
            writeValueToDisplayGroup();
        }
	}

    // interface FocusListener

	/**
	* Notifies of beginning of edit.
	*/
    public void focusGained(FocusEvent evt)
    {
        if ( ! isListening ) return;
		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 ( ! isListening ) return;
		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,
		}
    }

    /**
    * Returns whether the data model is updated for every change
    * in the controlled component.  If false, the data is only
    * updated on focus lost or the enter key.  Default is true.
    */
    public boolean isAutoUpdating()
    {
        if ( format() != null ) return false;
        return autoUpdating;
    }

    /**
    * Sets whether the data model is updated for every change
    * in the controlled component.
    */
    public void setAutoUpdating( boolean isAutoUpdating )
    {
        autoUpdating = isAutoUpdating;
    }

    /**
    * Triggers the key timer to start.
    */
    protected void queueUpdate()
    {
        if ( isAutoUpdating() )
        {
            if ( keyTimer == null )
            {
                keyTimer = new Timer( interval, this );
            }
            keyTimer.restart();
        }
    }

   // interface DocumentListener

   public void insertUpdate(DocumentEvent e)
   {
       if ( ! isListening ) return;
	   needsUpdate = true;
       queueUpdate();
   }

   public void removeUpdate(DocumentEvent e)
   {
       if ( ! isListening ) return;
	   needsUpdate = true;
       queueUpdate();
   }

   public void changedUpdate(DocumentEvent e)
   {
       if ( ! isListening ) return;
       needsUpdate = true;
       queueUpdate();
   }

}

/*
 * $Log$
 * 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 1.3  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  2001/12/20 18:57:24  mpowers
 * (Re-)Contributing TimedTextAssociation.  Just like TA, except uses timers.
 *
 * Revision 1.20  2001/10/26 19:58:06  mpowers
 * Better handling for non-string types.  We were testing with equals with the
 * new value against the existing value in the component.  Now we convert
 * the new value to a string before comparing.  Fixes case for properties
 * of non-String types, like StringBuffer.
 *
 * Revision 1.19  2001/09/30 21:57:14  mpowers
 * Timers were not getting cleaned up if breakConnection was called
 * before the timer got a chance to fire.
 *
 * Revision 1.18  2001/08/22 15:42:26  mpowers
 * Added support for JTextComponent label-izing.
 *
 * Revision 1.17  2001/07/30 16:32:55  mpowers
 * Implemented support for bulk-editing.  Detail associations will now
 * apply changes to all selected objects.
 *
 * Revision 1.16  2001/07/17 19:53:37  mpowers
 * Made some private fields protected for benefit of subclassers.
 *
 * Revision 1.15  2001/06/30 14:59:36  mpowers
 * LabelAspect now sets the text field's opaque setting.
 *
 * Revision 1.14  2001/06/29 14:54:08  mpowers
 * Another fix for timers - timers were definitely causing a memory leak.
 *
 * Revision 1.13  2001/06/26 21:37:19  mpowers
 * Fixed a null pointer in the new key timer scheme.
 *
 * Revision 1.12  2001/06/25 14:46:03  mpowers
 * Fixed a memory leak involving the use of timers.
 *
 * Revision 1.11  2001/06/01 19:14:59  mpowers
 * Text association's enabled aspect is now more discriminating.
 *
 * Revision 1.10  2001/05/18 21:07:24  mpowers
 * Changed the way we handle failure to update object value.
 *
 * Revision 1.9  2001/03/13 21:39:58  mpowers
 * Improved validation handling.
 *
 * Revision 1.8  2001/03/12 12:49:10  mpowers
 * Improved validation handling.
 * Having a formatter disables auto-updating.
 *
 * Revision 1.7  2001/03/09 22:08:13  mpowers
 * Now handling any objects that have a valid Document.
 * No longer checking enabled before updating the enabled state.
 *
 * Revision 1.6  2001/03/07 19:57:32  mpowers
 * Fixed paste error in IconAspect.
 *
 * Revision 1.4  2001/02/17 16:52:05  mpowers
 * Changes in imports to support building with jdk1.1 collections.
 *
 * Revision 1.3  2001/01/31 19:12:33  mpowers
 * Implemented auto-updating in TextComponent.
 *
 * Revision 1.2  2001/01/10 15:53:58  mpowers
 * Preventing a null pointer exception if getText were to return null,
 * which doesn't happen for JTextFields but might happen for other objects.
 *
 * Revision 1.1.1.1  2000/12/21 15:49:08  mpowers
 * Contributing wotonomy.
 *
 * Revision 1.13  2000/12/20 16:25:41  michael
 * Added log to all files.
 *
 *
 */