/*
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.lang.reflect.InvocationTargetException;
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.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.AbstractDocument;
import javax.swing.text.DefaultStyledDocument;
import javax.swing.text.Document;
import javax.swing.text.JTextComponent;
import net.wotonomy.foundation.NSArray;
import net.wotonomy.foundation.NSDictionary;
import net.wotonomy.foundation.NSNotification;
import net.wotonomy.foundation.NSNotificationCenter;
import net.wotonomy.foundation.NSNotificationQueue;
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;
/**
* TextAssociation binds JTextComponents and other objects with getText() and
* setText() methods to a display group. Note that JLabels are supported with
* both the Text and Icon aspects. Bindings are:
*
* - value: a property convertable to/from a string
* - editable: a boolean property that determines whether the user can edit
* the text in the field
* - enabled: a boolean property that determines whether the user can select
* the text in the field
* - visible: a boolean property that determines whether the field is
* visible
* - label: a boolean property that determines whether field should appear as
* a read-only, selectable label
* - 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.
*
*
* @author michael@mpowers.net
* @author $Author: cgruber $
* @version $Revision: 904 $
*/
public class TextAssociation extends EOAssociation implements FocusListener, ActionListener, DocumentListener {
static final NSArray aspects = new NSArray(
new Object[] { ValueAspect, EnabledAspect, EditableAspect, VisibleAspect, LabelAspect, IconAspect });
static final NSArray aspectSignatures = new NSArray(
new Object[] { AttributeToOneAspectSignature, AttributeToOneAspectSignature, AttributeToOneAspectSignature,
AttributeToOneAspectSignature, AttributeToOneAspectSignature, AttributeToOneAspectSignature });
static final NSArray objectKeysTaken = new NSArray(new Object[] { "text", "enabled", "editable", "visible" });
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;
// on-the-fly validation
protected boolean activeUpdate;
// type conversion
protected Class lastKnownType;
// cache the value aspect
private EODisplayGroup valueDisplayGroup;
private String valueKey;
// hacky flags needed for no activeUpdate
private boolean pleaseIgnoreNextChange = false;
private boolean pleaseAcceptNextChange = false;
private boolean externallyChanged = true;
/**
* Constructor specifying the object to be controlled by this association. Does
* not establish connection.
*/
public TextAssociation(Object anObject) {
super(anObject);
wasNull = false;
needsUpdate = false;
activeUpdate = true;
hasDocument = false;
isListening = true;
valueDisplayGroup = null;
valueKey = null;
format = null;
lastKnownType = null;
// register for idle notifications
NSSelector handleNotification = new NSSelector("handleNotification", new Class[] { NSNotification.class });
NSNotificationCenter.defaultCenter().addObserver(this, handleNotification, null, this);
}
/**
* 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.
*
* - "A" attribute: the aspect can be bound to an attribute.
* - "1" to-one: the aspect can be bound to a property that returns a single
* object.
* - "M" to-one: the aspect can be bound to a property that returns multiple
* objects.
*
* 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();
}
public void objectWillChange(Object anObject) {
super.objectWillChange(anObject);
externallyChanged = true;
}
/**
* Called when either the selection or the contents of an associated display
* group have changed.
*/
public void subjectChanged() {
if (pleaseIgnoreNextChange) {
pleaseIgnoreNextChange = false;
externallyChanged = false;
return;
}
externallyChanged = true;
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));
}
// if activeUpdate or we are not the editing association
if (activeUpdate || displayGroup.editingAssociation() != this || pleaseAcceptNextChange) {
pleaseAcceptNextChange = false;
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 = previousValue;
// 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 && previousValue != null
&& !currentValue.toString().equals(previousValue.toString())) {
value = null;
break;
}
} // end while
} else {
// if there's only one object selected.
value = displayGroup.selectedObjectValueForKey(key);
} // end checking the size of selected objects in displayGroup
// null handling
if (value == null) {
wasNull = true;
value = EMPTY_STRING;
lastKnownType = null;
} else {
wasNull = false;
lastKnownType = value.getClass();
if (format() != null) {
try {
value = format().format(value);
} catch (IllegalArgumentException exc) {
value = value.toString();
}
}
}
try {
if (needToReadValueFromDisplayGroup(value.toString(), getText)) {
// 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());
}
}
}
// visible aspect
displayGroup = displayGroupForAspect(VisibleAspect);
key = displayGroupKeyForAspect(VisibleAspect);
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 = (Boolean) ValueConverter.convertObjectToClass(value, Boolean.class);
if (converted != null) {
if (converted.booleanValue() != ((Component) component).isVisible()) {
((Component) component).setVisible(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");
aTextField.setBorder(null);
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");
aTextArea.setBorder(null);
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() {
pleaseAcceptNextChange = true;
pleaseIgnoreNextChange = false;
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;
}
}
if ((lastKnownType != null) && (value != null)) {
// convert back to last known type, if necessary/possible
Class type = value.getClass();
if ((type != null) && (type != lastKnownType)) {
Object converted = ValueConverter.convertObjectToClass(value, lastKnownType);
if (converted != null) {
value = converted;
}
// else: not possible, ignore
}
}
needsUpdate = false;
// only update if the value is different from the one in the display group
if (!needToWriteValueToDisplayGroup(value, displayGroup))
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)) {
needsUpdate = false;
} else {
needsUpdate = false;
returnValue = false;
}
}
isListening = wasListening;
}
return returnValue;
}
/**
* Called to determine whether the display group needs to be updated. This
* implementation reads the value from the display group and only returns true
* if the specified value is different. This is done as an optimization since
* writes are more expensive than reads. Override to customize this behavior.
*/
protected boolean needToWriteValueToDisplayGroup(Object aValue, EODisplayGroup aDisplayGroup) {
Object existingValue = aDisplayGroup.selectedObjectValueForKey(valueKey);
if (aDisplayGroup.selectedObjects().size() == 1) {
if (existingValue == aValue)
return false;
if ((existingValue != null) && (existingValue.equals(aValue)))
return false;
if ((aValue != null) && (aValue.equals(existingValue)))
return false;
}
return true;
}
/**
* Called to determine whether the controlled component needs to be updated.
* This implementation reads the value from the selector and only returns true
* if the specified value is different. This is done as an optimization since
* updating the component can be an expensive operation. Override to customize
* this behavior.
*/
protected boolean needToReadValueFromDisplayGroup(Object aValue, NSSelector aSelector)
throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
return !aValue.toString().equals(aSelector.invoke(object()));
}
/**
* Sets the Format that is used to convert values from the display group to and
* from text that is displayed in the component.
*/
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;
}
/**
* Returns whether the text association is configured to actively update the
* model in response to changes in the component.
*/
public boolean isActiveUpdate() {
return activeUpdate;
}
/**
* Sets whether the text association should actively update the model in
* response to changes in the component. Default is true. False indicates that
* the model will be updated only when the component loses focus or fires an
* action event.
*/
public void setActiveUpdate(boolean isActiveUpdate) {
activeUpdate = isActiveUpdate;
}
// interface ActionListener
/**
* Updates object on action performed.
*/
public void actionPerformed(ActionEvent evt) {
if (!isListening)
return;
if (needsUpdate) {
pleaseAcceptNextChange = true; // needed if activeUpdate = false
writeValueToDisplayGroup();
}
}
// interface FocusListener
/**
* Notifies of beginning of edit.
*/
public void focusGained(FocusEvent evt) {
if (!isListening)
return;
pleaseAcceptNextChange = true;
externallyChanged = true;
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,
}
}
/**
* Queues a notification to PostWhenIdle.
*/
protected void queueUpdate(DocumentEvent e) {
if (e.getDocument() instanceof DefaultStyledDocument) {
if (e instanceof AbstractDocument.DefaultDocumentEvent) {
int docLength = e.getDocument().getLength();
if ((e.getType().equals(DocumentEvent.EventType.CHANGE))) {
if (e.getOffset() == 0 && e.getLength() == docLength) {
// ignore document events for the whole document
// since default styled document broadcasts these
// using invokeLater, and we've already received
// notification about the actual style change.
// see: DefaultStyledDocument.ChangeUpdateRunnable
return;
}
}
}
}
NSNotificationQueue.defaultQueue().enqueueNotification(
new NSNotification("TextAssociation.DocumentChanged", this,
new NSDictionary(new Object[] { "event" }, new Object[] { e })),
NSNotificationQueue.PostWhenIdle);
}
/**
* Handles idle notification.
*/
public void handleNotification(NSNotification aNotification) {
if (activeUpdate) {
writeValueToDisplayGroup();
}
}
// interface DocumentListener
public void insertUpdate(DocumentEvent e) {
if (!isListening)
return;
needsUpdate = true;
queueUpdate(e);
}
public void removeUpdate(DocumentEvent e) {
if (!isListening)
return;
needsUpdate = true;
queueUpdate(e);
}
public void changedUpdate(DocumentEvent e) {
if (!isListening)
return;
needsUpdate = true;
queueUpdate(e);
}
}
/*
* $Log$ 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 1.41 2004/02/05 02:18:18 mpowers Now setting border to null to new
* Aqua LAF behaves.
*
* Revision 1.40 2004/01/28 22:47:56 mpowers un-activeUpdate was brokne.
*
* Revision 1.39 2004/01/28 18:34:57 mpowers Better handling for enabling. Now
* respecting enabledToSetSelectedObjectValueForKey from display group.
*
* Revision 1.38 2003/08/06 23:07:52 chochos general code cleanup (mostly,
* removing unused imports)
*
* Revision 1.37 2003/02/06 16:21:34 mpowers Fix for activeUpdate: no longer
* bothering with editing context's changes.
*
* Revision 1.36 2002/10/24 18:19:24 mpowers Bug fix - thanks to dwang.
*
* Revision 1.35 2002/08/02 19:19:30 mpowers Added control points for when to
* read or write from the display group. Added flags needed to fix problems with
* non-activeUpdate and commit key.
*
* Revision 1.33 2002/03/08 23:18:01 mpowers Added visible aspect.
*
* Revision 1.32 2002/03/06 16:13:53 mpowers Yet another fix for style document
* changes: swing's DefaultStyledDocument using an invoke later to launch a
* final StyleChanged event, which occurs after the TextAssociation has
* reestablished itself as a document listener, causing the item to be marked
* dirty. We're now handling this case.
*
* Revision 1.31 2002/03/04 22:10:37 mpowers Supressing active update only marks
* dirty when contents have changed.
*
* Revision 1.30 2002/02/23 16:19:12 mpowers Now only marking an editing context
* as dirty if it's not already dirty.
*
* Revision 1.29 2002/02/19 18:38:29 mpowers Minor optimization: activeUpdate
* now checked in handleNotification.
*
* Revision 1.28 2002/02/19 16:36:47 mpowers Better support for active update:
* objects are now marked as changed even though the model itself is not updated
* -- this allows editing context itself to be marked as having changes to be
* saved.
*
* Revision 1.27 2002/01/23 19:50:11 mpowers Fix for a null pointer when value
* is null and last known type is not. (from dwang)
*
* Revision 1.26 2002/01/14 19:37:22 mpowers Fix for NPE when value is null and
* auto update is false.
*
* Revision 1.25 2001/12/10 03:16:11 mpowers Fixed bug with isListening when no
* items are in display group.
*
* Revision 1.24 2001/11/16 19:14:51 mpowers Brought back the idea of
* configuring whether updates occur on each change.
*
* Revision 1.23 2001/11/08 20:06:06 mpowers Now performing type-conversion as a
* convenience.
*
* Revision 1.22 2001/11/04 18:24:20 mpowers Better handling for non-string
* values when bulk-editing.
*
* Revision 1.21 2001/11/01 15:53:34 mpowers Now that NSNotificationQueue
* correctly implements PostWhenIdle, we can finally discard our use of Swing's
* Timer in favor of using the queue to coalesce document changed events.
*
* 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.
*
*
*/