/*
 * 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.commons.collections4.set;

import java.util.Set;

import org.apache.commons.collections4.Predicate;
import org.apache.commons.collections4.collection.PredicatedCollection;

Decorates another Set to validate that all additions
match a specified predicate.

This set exists to provide validation for the decorated set.
It is normally created to decorate an empty set.
If an object cannot be added to the set, an IllegalArgumentException is thrown.


One usage would be to ensure that no null entries are added to the set.

Set set = PredicatedSet.decorate(new HashSet(), NotNullPredicate.INSTANCE);

This class is Serializable from Commons Collections 3.1.

Type parameters:
<E> – the type of the elements in this set
Since:
3.0/**
 * Decorates another <code>Set</code> to validate that all additions
 * match a specified predicate.
 * <p>
 * This set exists to provide validation for the decorated set.
 * It is normally created to decorate an empty set.
 * If an object cannot be added to the set, an IllegalArgumentException is thrown.
 * </p>
 * <p>
 * One usage would be to ensure that no null entries are added to the set.
 * </p>
 * <pre>Set set = PredicatedSet.decorate(new HashSet(), NotNullPredicate.INSTANCE);</pre>
 * <p>
 * This class is Serializable from Commons Collections 3.1.
 * </p>
 *
 * @param <E> the type of the elements in this set
 * @since 3.0
 */
public class PredicatedSet<E> extends PredicatedCollection<E> implements Set<E> {

    
Serialization version /** Serialization version */
    private static final long serialVersionUID = -684521469108685117L;

    
Factory method to create a predicated (validating) set.

If there are any elements already in the set being decorated, they
are validated.
Params:
set –  the set to decorate, must not be null
predicate –  the predicate to use for validation, must not be null
Type parameters:
<E> – the element type
Throws:
NullPointerException – if set or predicate is null
IllegalArgumentException – if the set contains invalid elements
Returns:
a decorated set
Since:
4.0/**
     * Factory method to create a predicated (validating) set.
     * <p>
     * If there are any elements already in the set being decorated, they
     * are validated.
     *
     * @param <E> the element type
     * @param set  the set to decorate, must not be null
     * @param predicate  the predicate to use for validation, must not be null
     * @return a decorated set
     * @throws NullPointerException if set or predicate is null
     * @throws IllegalArgumentException if the set contains invalid elements
     * @since 4.0
     */
    public static <E> PredicatedSet<E> predicatedSet(final Set<E> set, final Predicate<? super E> predicate) {
        return new PredicatedSet<>(set, predicate);
    }

    //-----------------------------------------------------------------------
    
Constructor that wraps (not copies).

If there are any elements already in the set being decorated, they
are validated.
Params:
set –  the set to decorate, must not be null
predicate –  the predicate to use for validation, must not be null
Throws:
NullPointerException – if set or predicate is null
IllegalArgumentException – if the set contains invalid elements/**
     * Constructor that wraps (not copies).
     * <p>
     * If there are any elements already in the set being decorated, they
     * are validated.
     *
     * @param set  the set to decorate, must not be null
     * @param predicate  the predicate to use for validation, must not be null
     * @throws NullPointerException if set or predicate is null
     * @throws IllegalArgumentException if the set contains invalid elements
     */
    protected PredicatedSet(final Set<E> set, final Predicate<? super E> predicate) {
        super(set, predicate);
    }

    
Gets the set being decorated.
Returns:
the decorated set/**
     * Gets the set being decorated.
     *
     * @return the decorated set
     */
    @Override
    protected Set<E> decorated() {
        return (Set<E>) super.decorated();
    }

    @Override
    public boolean equals(final Object object) {
        return object == this || decorated().equals(object);
    }

    @Override
    public int hashCode() {
        return decorated().hashCode();
    }

}