WrappedValueAbstract.java

/*
 * Aphelion
 * Copyright (c) 2013  Joris van der Wel
 * 
 * This file is part of Aphelion
 * 
 * Aphelion is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, version 3 of the License.
 * 
 * Aphelion 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with Aphelion.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * In addition, the following supplemental terms apply, based on section 7 of
 * the GNU Affero General Public License (version 3):
 * a) Preservation of all legal notices and author attributions
 * b) Prohibition of misrepresentation of the origin of this material, and
 * modified versions are required to be marked in reasonable ways as
 * different from the original version (for example by appending a copyright notice).
 * 
 * Linking this library statically or dynamically with other modules is making a
 * combined work based on this library. Thus, the terms and conditions of the
 * GNU Affero General Public License cover the whole combination.
 * 
 * As a special exception, the copyright holders of this library give you 
 * permission to link this library with independent modules to produce an 
 * executable, regardless of the license terms of these independent modules,
 * and to copy and distribute the resulting executable under terms of your 
 * choice, provided that you also meet, for each linked independent module,
 * the terms and conditions of the license of that module. An independent
 * module is a module which is not derived from or based on this library.
 */

package aphelion.shared.gameconfig;

import aphelion.shared.swissarmyknife.WeakList;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;

/**
 *
 *  
 * @author Joris
 */
public abstract class WrappedValueAbstract
{
        final ConfigSelection selection;
        final String key;
        protected boolean set;
        private final WeakList<ChangeListener> listeners = new WeakList<>();

        WrappedValueAbstract(@Nonnull ConfigSelection selection, @Nonnull String key)
        {
                this.selection = selection;
                this.key = key;
        }
        
        public boolean isSet()
        {
                return set;
        }
        
        protected final void fireChangeListener()
        {
                for (ChangeListener listener : listeners)
                {
                        listener.gameConfigValueChanged(this);
                }
        }
        
        public void addWeakChangeListener(@Nonnull ChangeListener listener)
        {
                listeners.cleanup();
                listeners.add(listener);
        }
        
        public void addWeakChangeListenerAndFire(@Nonnull ChangeListener listener)
        {
                addWeakChangeListener(listener);
                listener.gameConfigValueChanged(this);
        }
        
        public void removeWeakChangeListener(@Nullable ChangeListener listener)
        {
                listeners.remove(listener);
                listeners.cleanup();
        }
        
        /** A new value is coming from yaml.
         * @return true if the new value is different from the old one
         */
        abstract boolean newValue(@Nullable Object value);
        
        public static interface ChangeListener
        {
                void gameConfigValueChanged(@Nonnull WrappedValueAbstract val);
        }
        
        public static interface Factory
        {
                WrappedValueAbstract create(@Nonnull ConfigSelection selection, @Nonnull String key);
        }
}