/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.brooklyn.core.entity;
import static com.google.common.base.Preconditions.checkNotNull;
import org.apache.brooklyn.api.entity.Entity;
import org.apache.brooklyn.api.entity.EntityLocal;
import org.apache.brooklyn.api.sensor.AttributeSensor;
import com.google.common.base.Objects;
import com.google.common.base.Supplier;
/**
* A tuple containing an {@link Entity} and an {@link AttributeSensor}, which is assumed to be present on the entity.
* <p>
* Allows retrieval of the attribute {@link #getValue() value} or can be used instead where a {@link Supplier} for
* the attribute value is required.
*/
public class EntityAndAttribute<T> implements Supplier<T> {
private final Entity entity;
private final AttributeSensor<T> attribute;
public static <T> EntityAndAttribute<T> create(Entity entity, AttributeSensor<T> attribute) {
return new EntityAndAttribute<T>(entity, attribute);
}
/**
* @deprecated since 0.7.0; use {@link #create(Entity, AttributeSensor)}; this does not relate to {@link Supplier}
*/
public static <T> EntityAndAttribute<T> supplier(Entity entity, AttributeSensor<T> attribute) {
return create(entity, attribute);
}
public EntityAndAttribute(Entity entity, AttributeSensor<T> attribute) {
this.entity = checkNotNull(entity, "entity");
this.attribute = checkNotNull(attribute, "attribute");
}
public Entity getEntity() {
return entity;
}
public AttributeSensor<T> getAttribute() {
return attribute;
}
public T getValue() {
return entity.getAttribute(attribute);
}
public void setValue(T val) {
((EntityLocal)entity).sensors().set(attribute, val);
}
/**
* {@inheritDoc}
*
* Returns the current value of the {@link #getAttribute() attribute} on the {@link #getEntity() entity}.
*
* @see #getValue()
*/
@Override
public T get() {
return getValue();
}
@Override
public String toString() {
return Objects.toStringHelper(this)
.add("entity", entity)
.add("attribute", attribute)
.toString();
}
@Override
public int hashCode() {
return Objects.hashCode(entity, attribute);
}
@Override
public boolean equals(Object o) {
if (o == null) return false;
if (!(o instanceof EntityAndAttribute)) return false;
EntityAndAttribute<?> that = (EntityAndAttribute<?>) o;
return Objects.equal(this.entity, that.entity) &&
Objects.equal(this.attribute, that.attribute);
}
}