tutorials/cargo/src/main/java/org/qi4j/tutorials/cargo/step2/SequencingConcern.java

/*
 * Copyright 2007, 2008 Niclas Hedhman.
 *
 * Licensed  under the  Apache License,  Version 2.0  (the "License");
 * you may not use  this file  except in  compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed  under the  License is distributed on an "AS IS" BASIS,
 * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
 * implied.
 *
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.qi4j.tutorials.cargo.step2;

import org.qi4j.api.concern.ConcernOf;
import org.qi4j.api.injection.scope.This;
import org.qi4j.api.property.Property;

public class SequencingConcern
    extends ConcernOf<ShippingService>
    implements ShippingService
{
    @This
    private HasSequence generator;

    @Override
    public int makeBooking( Cargo cargo, Voyage voyage )
    {
        int ok = next.makeBooking( cargo, voyage );
        if( ok < 0 )
        {
            return ok;
        }
        Property<Integer> gen = generator.sequence();
        ok = gen.get();
        generator.sequence().set( ok + 1 );
        return ok;
    }
}