/*
* Copyright 2015 Red Hat, Inc. and/or its affiliates.
*
* 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.optaplanner.core.api.domain.variable;
import org.optaplanner.core.api.domain.entity.PlanningEntity;
/**
* A reference to a genuine {@link PlanningVariable} or a shadow variable.
*/
public @interface PlanningVariableReference {
/**
* The {@link PlanningEntity} class of the planning variable.
* <p>
* Specified if the planning variable is on a different {@link Class}
* than the class that uses this referencing annotation.
* @return {@link NullEntityClass} when it is null (workaround for annotation limitation).
* Defaults to the same {@link Class} as the one that uses this annotation.
*/
Class<?> entityClass() default NullEntityClass.class;
/** Workaround for annotation limitation in {@link #entityClass()}. */
interface NullEntityClass {}
/**
* The name of the planning variable that is referenced.
* @return never null, a genuine or shadow variable name
*/
String variableName();
}