/*
* Copyright (c) 2013, MGrossmann
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the jo-widgets.org nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL jo-widgets.org BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
package org.jowidgets.util;
/**
* Implements an observable value that never has null values.
*
* If set to null, a given default value will be used
*
* @author MGrossmann
*
* @param <VALUE_TYPE>
*/
public class MandatoryObservableValue<VALUE_TYPE> extends ObservableValue<VALUE_TYPE> {
private final VALUE_TYPE defaultValue;
public MandatoryObservableValue(final VALUE_TYPE defaultValue) {
Assert.paramNotNull(defaultValue, "defaultValue");
this.defaultValue = defaultValue;
}
@Override
public void setValue(final VALUE_TYPE value) {
if (value != null) {
super.setValue(value);
}
else {
super.setValue(defaultValue);
}
}
@Override
public VALUE_TYPE getValue() {
final VALUE_TYPE superResult = super.getValue();
if (superResult != null) {
return superResult;
}
else {
return defaultValue;
}
}
}