/*
* Copyright (C) 2012, Katy Hilgenberg.
* Special acknowledgments to: Knowledge & Data Engineering Group, University of Kassel (http://www.kde.cs.uni-kassel.de).
* Contact: sdcf@cs.uni-kassel.de
*
* This file is part of the SDCFramework (Sensor Data Collection Framework) project.
*
* The SDCFramework 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 3 of the License, or
* (at your option) any later version.
*
* The SDCFramework 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 the SDCFramework. If not, see <http://www.gnu.org/licenses/>.
*/
package de.unikassel.android.sdcframework.preferences;
import java.security.InvalidParameterException;
import de.unikassel.android.sdcframework.preferences.facade.SinglePreference;
/**
* Generic abstract base class for a single preference type. <br/>
* <br/>
* The key for the Android shared preferences will be constructed from the
* keyPrefix and keySuffix values provided in the
* {@linkplain #SinglePreferenceImpl(String, String, Object) constructor call}.
*
* @author Katy Hilgenberg
* @param <T>
* the type of the preference value
*
*/
public abstract class SinglePreferenceImpl< T > implements SinglePreference< T >
{
/**
* Default preference value
*/
private T defaultValue;
/**
* The key value for the Android preferences
*/
private final String key;
/**
* Constructor
*
* @param key
* the key value
* @param defaultValue
* the default value
*/
protected SinglePreferenceImpl( String key, T defaultValue )
{
super();
if( defaultValue == null )
throw new InvalidParameterException( "default value is null" );
if( key == null )
throw new InvalidParameterException( "key is null" );
this.key = key;
setDefault( defaultValue );
}
/**
* Constructor
*
* @param keyPrefix
* the key prefix
* @param keySuffix
* the key suffix
* @param defaultValue
* the default value
*/
public SinglePreferenceImpl( String keyPrefix, String keySuffix,
T defaultValue )
{
this( keyPrefix + "_" + keySuffix, defaultValue );
}
/*
* (non-Javadoc)
*
* @see
* de.unikassel.android.sdcframework.preferences.facade.SinglePreference#getKey
* ()
*/
@Override
public final String getKey()
{
return key;
}
/*
* (non-Javadoc)
*
* @see de.unikassel.android.sdcframework.preferences.facade.SinglePreference#
* getDefault()
*/
@Override
public final T getDefault()
{
return defaultValue;
}
/*
* (non-Javadoc)
*
* @see de.unikassel.android.sdcframework.preferences.facade.SinglePreference#
* setDefault(java.lang.Object)
*/
@Override
public final void setDefault( T defaultValue )
{
// we do never override defaults with null values
if( defaultValue != null )
this.defaultValue = defaultValue;
}
/* (non-Javadoc)
* @see de.unikassel.android.sdcframework.preferences.facade.SinglePreference#testForKey(java.lang.String)
*/
@Override
public boolean testForKey( String key )
{
return this.key.equals( key );
}
}