/*
* Copyright (c) 2005-2016 Vincent Vandenschrick. All rights reserved.
*
* This file is part of the Jspresso framework.
*
* Jspresso 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.
*
* Jspresso 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 Jspresso. If not, see <http://www.gnu.org/licenses/>.
*/
package org.jspresso.framework.util.gate;
import java.util.Collection;
/**
* A simple gate that tracks collection selection (actually the sub-collection
* is set as model) and opens whenever the selection is a singleton.
*
* @author Vincent Vandenschrick
* @internal
*/
public class SingleCollectionSelectionTrackingGate extends
AbstractCollectionSelectionTrackingGate {
/**
* {@code INSTANCE} is a singleton instance of a gate whose state depends
* on the underlying collection connector selection (!singleton => closed,
* singleton => open).
*/
public static final SingleCollectionSelectionTrackingGate INSTANCE = new SingleCollectionSelectionTrackingGate();
/**
* Returns true whenever the model collection is not empty.
* <p>
* {@inheritDoc}
*/
@Override
public boolean isOpen() {
if (getModel() instanceof Collection<?>) {
return ((Collection<?>) getModel()).size() == 1;
}
return getModel() != null;
}
}