net.derquinse.common.meta.MetaFlag Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of derquinse-common-base Show documentation
Show all versions of derquinse-common-base Show documentation
Module containing support classes depending on Java SE 6, Guava 11 and Joda-Time 2.0
/*
* Copyright (C) the original author or authors.
*
* 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 net.derquinse.common.meta;
import java.util.Arrays;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
/**
* Base class for flag descriptors.
* @author Andres Rodriguez
* @param Containing type.
*/
public abstract class MetaFlag extends MetaField implements Predicate {
/** Default value. */
private final boolean defaultValue;
/** Property view. Preinstantiated to guarantee constant identity. */
private final FlagProperty property;
/**
* Default constructor.
* @param name Property name.
* @param defaultValue Default value for the flag.
*/
protected MetaFlag(String name, boolean defaultValue) {
super(name);
this.defaultValue = defaultValue;
this.property = new FlagProperty();
}
/**
* Constructor with a default value of false.
* @param name Property name.
*/
protected MetaFlag(String name) {
this(name, false);
}
/**
* Returns the default value.
*/
public final boolean getDefaultValue() {
return defaultValue;
}
/**
* Returns a view of the flag as a Boolean property.
*/
public final BooleanMetaProperty asProperty() {
return property;
}
/**
* Returns a predicate that evaluates to {@code true} if this flag evaluates to {@code false}.
*/
public final Predicate not() {
return Predicates.not(this);
}
/**
* Returns a predicate that evaluates to {@code true} if this flag and each of the provided
* components evaluates to {@code true}. The components are evaluated in order (after the flag),
* and evaluation will be "short-circuited" as soon as a false predicate is found. It defensively
* copies the iterable passed in, so future changes to it won't alter the behavior of this
* predicate.
*/
public final Predicate and(Iterable extends Predicate super C>> components) {
return Predicates.and(Iterables.concat(ImmutableList.of(this), components));
}
/**
* Returns a predicate that evaluates to {@code true} if this flag and each of the provided
* components components evaluates to {@code true}. The components are evaluated in order (after
* the flag), and evaluation will be "short-circuited" as soon as a false predicate is found. It
* defensively copies the array passed in, so future changes to it won't alter the behavior of
* this predicate.
*/
public final Predicate and(Predicate super C>... components) {
return and(Arrays.asList(components));
}
/**
* Returns a predicate that evaluates to {@code true} if both this flag and the provided predicate
* evaluate to {@code true}. The component is evaluated after the flag and evaluation will be
* "short-circuited" as soon as a false predicate is found.
*/
public final Predicate and(Predicate super C> other) {
return and(ImmutableList.of(other));
}
/**
* Returns a predicate that evaluates to {@code true} if any one of this flag or the provided
* components evaluates to {@code true}. The components are evaluated in order (after the flag),
* and evaluation will be "short-circuited" as soon as a true predicate is found. It defensively
* copies the iterable passed in, so future changes to it won't alter the behavior of this
* predicate.
*/
public final Predicate or(Iterable extends Predicate super C>> components) {
return Predicates.or(Iterables.concat(ImmutableList.of(this), components));
}
/**
* Returns a predicate that evaluates to {@code true} if any one of this flag or the provided
* components evaluates to {@code true}. The components are evaluated in order (after the flag),
* and evaluation will be "short-circuited" as soon as a true predicate is found. It defensively
* copies the iterable passed in, so future changes to it won't alter the behavior of this
* predicate.
*/
public final Predicate or(Predicate super C>... components) {
return or(Arrays.asList(components));
}
/**
* Returns a predicate that evaluates to {@code true} if any of this flag or the provided
* predicate evaluate to {@code true}. The argument is evaluated after the flag and evaluation
* will be "short-circuited" as soon as a true predicate is found.
*/
public final Predicate or(Predicate super C> other) {
return or(ImmutableList.of(other));
}
/**
* Flag view as a property.
*/
private final class FlagProperty extends BooleanMetaProperty {
FlagProperty() {
super(MetaFlag.this.getName(), true, Predicates.alwaysTrue(), defaultValue);
}
private MetaFlag get() {
return MetaFlag.this;
}
public Boolean apply(C input) {
return get().apply(input);
}
@Override
public boolean equals(Object obj) {
return this == obj;
}
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy