/*
* Copyright 2014 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 java.lang.annotation.Retention;
import java.lang.annotation.Target;
import org.optaplanner.core.api.domain.entity.PlanningEntity;
import org.optaplanner.core.api.solver.Solver;
import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;
/**
* Specifies that a bean property (or a field) is the inverse of a {@link PlanningVariable}, which implies it's a shadow variable.
* <p>
* It is specified on a getter of a java bean property (or a field) of a {@link PlanningEntity} class.
*/
@Target({METHOD, FIELD})
@Retention(RUNTIME)
public @interface InverseRelationShadowVariable {
/**
* In a bidirectional relationship, the shadow side (= the slave side) uses this property
* (and nothing else) to declare for which {@link PlanningVariable} (= the master side) it is a shadow.
* <p>
* Both sides of a bidirectional relationship should be consistent: if A points to B, then B must point to A.
* <p>
* When the {@link Solver} changes a genuine variable, it adjusts the shadow variable accordingly.
* In practice, the {@link Solver} ignores shadow variables (except for consistency housekeeping).
* @return the variable property name on the opposite end of this bidirectional relationship
*/
String sourceVariableName();
}