com.webobjects.eointerface
Class EOValueAssociation

java.lang.Object
  com.webobjects.eocontrol.EODelayedObserver
      com.webobjects.eointerface.EOAssociation
          com.webobjects.eointerface.EOWidgetAssociation
              com.webobjects.eointerface.EOValueAssociation

All Implemented Interfaces:

EOObserving, NSDisposable

Direct Known Subclasses:

EOPickTextAssociation, EOTextAssociation

public class EOValueAssociation

extends EOWidgetAssociation

EOValueAssociation is used for associations that display a single value object in a widget, with the value usually being editable. See EOAssociation for a general description of associations.

Aspects:

EOAssociation.ValueAspect,

EOAssociation.URLAspect,

EOAssociation.EnabledAspect

See Also:

EOAssociation

Nested Class Summary

static class

EOValueAssociation.ValuePlugin ValuePlugin communicates with a UI widget on behalf of an EOValueAssociation.

Nested classes inherited from class com.webobjects.eointerface.EOWidgetAssociation

EOWidgetAssociation.WidgetPlugin

Field Summary

Fields inherited from class com.webobjects.eointerface.EOAssociation

ActionAspect, ArgumentAspect, AttributeAspectSignature, AttributeToManyAspectSignature, AttributeToOneAspectSignature, AttributeToOneToManyAspectSignature, BackgroundColorAspect, BoldAspect, ChildrenAspect, DestinationAspect, EnabledAspect, ExpandedIconAspect, IconAspect, IgnoreValue, IsLeafAspect, ItalicAspect, MatchKey1Aspect, MatchKey2Aspect, MatchKey3Aspect, NullAspectSignature, ParentAspect, RootAspect, SelectedIndexAspect, SelectedObjectAspect, SelectedTitleAspect, SetValue, SourceAspect, TextColorAspect, TitlesAspect, ToManyAspectSignature, ToOneAspectSignature, ToOneToManyAspectSignature, UnsetValue, URLAspect, ValueAspect

Fields inherited from class com.webobjects.eocontrol.EODelayedObserver

ObserverNumberOfPriorities, ObserverPriorityFifth, ObserverPriorityFirst, ObserverPriorityFourth, ObserverPriorityImmediate, ObserverPriorityLater, ObserverPrioritySecond, ObserverPrioritySixth, ObserverPriorityThird

Constructor Summary

EOValueAssociation(Object widget)
Returns a new EOValueAssociation object that is not bound to any display group.

Method Summary

void	bindAspect(String aspect, EODisplayGroup displayGroup, String key) Defines the receiver's link between its display object and displayGroup.
protected String	displayValueAspect()
protected Object	displayValueFromURL(String URLString) When the Association stores a URL rather than the data the URL references, this method is used to obtain (load) the data pointed to by the URL.
boolean	endEditing() This method will end editing for both the widget plugin and the Association.
String	primaryAspect() This method returns the primary aspect for this value association.
void	subjectChanged() Overridden by subclasses to update state when an EODisplayGroup's selections or contents change.
boolean	widgetDidBeginEditing() This method is called to notify the Association that the widget entered the editing state.
boolean	widgetDidChange() This method is called to notify the Association that the widget has changed data values for this association.
boolean	widgetDidEndEditing() This method is called to notify the Association that the widget has no longer in an editing state.
protected Class	widgetPluginClass() Returns the Class of widget plugin that this association requires for operation.

Methods inherited from class com.webobjects.eointerface.EOWidgetAssociation

canSupportValueFormatter, defaultPrefersContinuousChangeNotification, dispose, isUsableWithObject, objectKeysTaken, prefersContinuousChangeNotification, setDefaultPrefersContinuousChangeNotification, setObject, setPrefersContinuousChangeNotification, setValueFormatter, valueFormatter, widgetPlugin

Methods inherited from class com.webobjects.eointerface.EOAssociation

aspects, aspectSignatures, associationClassesForObject, breakConnection, copyMatchingBindingsFromAssociation, displayGroupForAspect, displayGroupKeyForAspect, establishConnection, isConnected, isEnabled, isEnabledAtIndex, isExplicitlyDisabled, object, priority, registerAssociationClass, setExplicitlyDisabled, setValueForAspect, setValueForAspectAtIndex, shouldEndEditing, shouldEndEditingAtIndex, valueForAspect, valueForAspectAtIndex

Methods inherited from class com.webobjects.eocontrol.EODelayedObserver

discardPendingNotification, objectWillChange, observerQueue

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EOValueAssociation

public EOValueAssociation(Object widget)

Returns a new EOValueAssociation object that is not bound to any display group.

Parameters:

widget - the UI widget object that the association expects to use to display values

Method Detail

bindAspect

public void bindAspect(String aspect,
                       EODisplayGroup displayGroup,
                       String key)

Defines the receiver's link between its display object and displayGroup. aspect is the name of the aspect it observes in its display object, and key is the name of the property it observes in displayGroup. Invoke establishConnection after this method to finish setting up the binding.

Overrides:

bindAspect in class EOAssociation

Parameters:

aspect - String that specifies what key of this association should be used to bind to EnterpriseObjects values

displayGroup - EODisplayGroup object to bind this association to

key - String specifying which property of the EOs in the display group should be used when setting values for aspect

displayValueAspect

protected String displayValueAspect()

Returns:

String that represents which aspect of this EOValueAssociation is being used for supplying display values

displayValueFromURL

protected Object displayValueFromURL(String URLString)

When the Association stores a URL rather than the data the URL references, this method is used to obtain (load) the data pointed to by the URL.

Parameters:

URLString - the URL of some data to obtain

Returns:

a NSData object holding the actual data pointed to by the URL

endEditing

public boolean endEditing()

This method will end editing for both the widget plugin and the Association.

Overrides:

endEditing in class EOAssociation

Returns:

true if both the widget plugin and the assocaiation were able to successfully end editing; false otherwise

primaryAspect

public String primaryAspect()

This method returns the primary aspect for this value association.

Overrides:

primaryAspect in class EOAssociation

Returns:

the name of the primary aspect (EOAssociation.ValueAspect)

subjectChanged

public void subjectChanged()

Overridden by subclasses to update state when an EODisplayGroup's selections or contents change. This method is invoked automatically anytime a display group that's bound to the receiver changes. The receiver can query its display group with selectionChanged and contentsChanged messages to determine how to update the display.

Overrides:

subjectChanged in class EOAssociation

widgetDidBeginEditing

public boolean widgetDidBeginEditing()

This method is called to notify the Association that the widget entered the editing state.

Returns:

true if this association 'agreed' to start editing, false otherwise

widgetDidChange

public boolean widgetDidChange()

This method is called to notify the Association that the widget has changed data values for this association.

Returns:

true if the assocaiation was able to process the values received from the widget; false if there was an error

widgetDidEndEditing

public boolean widgetDidEndEditing()

This method is called to notify the Association that the widget has no longer in an editing state.

Returns:

true if the assocaiation was able to successfully complete the editing state; false otherwise

widgetPluginClass

protected Class widgetPluginClass()

Description copied from class: EOWidgetAssociation

Returns the Class of widget plugin that this association requires for operation. Subclasses should override this method to return the Class of plugin they require in order to work. (For example EOActionWidgetAsssociation requires a plugin class of EOActionWidgetAssociation.ActionPlugin).

Overrides:

widgetPluginClass in class EOWidgetAssociation

Returns:

the Class object for EOValueAssociation.ValuePlugin