/*******************************************************************************
* Copyright (c) 2010 Oracle. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0, which accompanies this distribution
* and is available at http://www.eclipse.org/legal/epl-v10.html.
*
* Contributors:
* Oracle - initial API and implementation
******************************************************************************/
package org.eclipse.jpt.utility.internal;
/**
* A NotBooleanTransformer
will transform a
* {@link Boolean} to its NOT value:
* - If the original {@link Boolean} is {@link Boolean#TRUE},
* the transformer will return {@link Boolean#FALSE}.
*
- If the original {@link Boolean} is {@link Boolean#FALSE},
* the transformer will return {@link Boolean#TRUE}.
*
- If the original {@link Boolean} is
null
,
* the transformer will return null
.
*
*/
public class NotBooleanTransformer
implements BidiTransformer
{
public static final BidiTransformer INSTANCE = new NotBooleanTransformer();
public static BidiTransformer instance() {
return INSTANCE;
}
// ensure single instance
private NotBooleanTransformer() {
super();
}
public Boolean transform(Boolean b) {
return (b == null) ? null : BooleanTools.not(b);
}
public Boolean reverseTransform(Boolean b) {
return (b == null) ? null : BooleanTools.not(b);
}
@Override
public String toString() {
return this.getClass().getSimpleName();
}
private static final long serialVersionUID = 1L;
private Object readResolve() {
// replace this object with the singleton
return INSTANCE;
}
}