core/runtime/src/main/java/org/apache/zest/runtime/entity/EntityPropertyInstance.java

/*
 * Copyright (c) 2007, Rickard Öberg. All Rights Reserved.
 * Copyright (c) 2008, Edward Yakop. 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.apache.zest.runtime.entity;

import org.apache.zest.runtime.property.PropertyInfo;
import org.apache.zest.runtime.property.PropertyInstance;
import org.apache.zest.spi.entity.EntityState;

/**
 * {@code EntityPropertyInstance} represents a property whose value must be backed by an EntityState.
 */
public class EntityPropertyInstance<T>
    extends PropertyInstance<T>
{
    private final EntityState entityState;

    /**
     * Construct an instance of {@code PropertyInstance} with the specified arguments.
     *
     * @param aPropertyInfo The property info. This argument must not be {@code null}.
     * @param entityState EntityState
     */
    @SuppressWarnings( "unchecked" )
    public EntityPropertyInstance( PropertyInfo aPropertyInfo, EntityState entityState )
    {
        super( aPropertyInfo, (T) entityState.propertyValueOf( aPropertyInfo.qualifiedName() ) );
        this.entityState = entityState;
    }

    /**
     * Sets this property value.
     *
     * @param aNewValue The new value.
     */
    @Override
    public void set( T aNewValue )
    {
        super.set( aNewValue );
        entityState.setPropertyValue( model.qualifiedName(), aNewValue );
    }
}