net.sf.jguiraffe.gui.builder.enablers

Class NullEnabler

java.lang.Object

net.sf.jguiraffe.gui.builder.enablers.NullEnabler

All Implemented Interfaces:

ElementEnabler

public class NullEnabler
extends Object
implements ElementEnabler

A trivial implementation of the ElementEnabler interface that does nothing.

This class provides an empty dummy implementation of the setEnabledState() method. It can be used as an application of the null object pattern where an ElementEnabler is optional.

Version:

$Id: NullEnabler.java 205 2012-01-29 18:29:57Z oheger $

Author:

Oliver Heger

Field Summary

Fields

Modifier and Type	Field and Description
static NullEnabler	INSTANCE A constant for a default instance of this class.

Constructor Summary

Constructors

Constructor and Description
NullEnabler()

Method Summary

Modifier and Type	Method and Description
void	setEnabledState(ComponentBuilderData compData, boolean state) Changes the enabled state of the element this ElementEnabler is responsible for.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final NullEnabler INSTANCE

A constant for a default instance of this class.

Constructor Detail

NullEnabler

public NullEnabler()

Method Detail

setEnabledState

public void setEnabledState(ComponentBuilderData compData,
                            boolean state)
                     throws FormBuilderException

Changes the enabled state of the element this ElementEnabler is responsible for. This method is always called when the enabled state of elements has to be changed. The passed in ComponentBuilderData object can be used for accessing relevant elements; especially the BeanContext maintained by this object can be used for retrieving all objects available in the current builder context. The boolean argument determines whether the associated element should be enabled or disabled. If the state of the element cannot be changed - for whatever reason -, an implementation should throw a FormBuilderException. An empty dummy implementation of this interface method. It does literally nothing.

Specified by:

setEnabledState in interface ElementEnabler

Parameters:

compData - a reference to the current ComponentBuilderData object

state - the new enabled state of the associated element: true if the element is to be enabled, false if it should be disabled

Throws:

FormBuilderException - if the state of the element cannot be changed