# ApplicationDetailDescriptor.java

    /*
     * Copyright (c) 2008, Edward Yakop. All Rights Reserved.
     * Copyright (c) 2014-2015, Paul Merlin. All Rights Reserved.
     *
     * 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.tools.model.descriptor;

    import java.util.LinkedList;
    import java.util.List;
    import org.qi4j.api.structure.ApplicationDescriptor;
    import org.qi4j.functional.HierarchicalVisitor;
    import org.qi4j.functional.VisitableHierarchy;

    import static org.qi4j.api.util.NullArgumentException.validateNotNull;

    /**
     * Application Detail Descriptor.
     * <p>
     * Visitable hierarchy with Activators and Layers children.
     */
    public final class ApplicationDetailDescriptor
        implements ActivateeDetailDescriptor, VisitableHierarchy<Object, Object>
    {
        private final ApplicationDescriptor descriptor;
        private final List<ActivatorDetailDescriptor> activators = new LinkedList<>();
        private final List<LayerDetailDescriptor> layers = new LinkedList<>();

        ApplicationDetailDescriptor( ApplicationDescriptor descriptor )
            throws IllegalArgumentException
        {
            validateNotNull( "ApplicationDescriptor", descriptor );
            this.descriptor = descriptor;
        }

        /**
         * @return Descriptor of this {@code ApplicationDetailDescriptor}. Never return {@code null}.
         */
        public final ApplicationDescriptor descriptor()
        {
            return descriptor;
        }

        @Override
        public Iterable<ActivatorDetailDescriptor> activators()
        {
            return activators;
        }

        /**
         * @return Layers of this {@code ApplicationDetailDescriptor}. Never return {@code null}.
         */
        public final Iterable<LayerDetailDescriptor> layers()
        {
            return layers;
        }

        final void addActivator( ActivatorDetailDescriptor descriptor )
        {
            validateNotNull( "ActivatorDetailDescriptor", descriptor );
            descriptor.setApplication( this );
            activators.add( descriptor );
        }

        final void addLayer( LayerDetailDescriptor descriptor )
        {
            validateNotNull( "LayerDetailDescriptor", descriptor );
            descriptor.setApplication( this );
            layers.add( descriptor );
        }

        @Override
        public final String toString()
        {
            return descriptor.name();
        }

        @Override
        public <ThrowableType extends Throwable> boolean accept( HierarchicalVisitor<? super Object, ? super Object, ThrowableType> visitor )
            throws ThrowableType
        {
            if( visitor.visitEnter( this ) )
            {
                for( ActivatorDetailDescriptor activator : activators )
                {
                    if( !activator.accept( visitor ) )
                    {
                        break;
                    }
                }
                for( LayerDetailDescriptor layer : layers )
                {
                    if( !layer.accept( visitor ) )
                    {
                        break;
                    }
                }
            }
            return visitor.visitLeave( this );
        }
    }