/**
 * Copyright 2010 Google Inc.
 *
 * 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.waveprotocol.wave.model.adt;

import org.waveprotocol.wave.model.util.CollectionUtils;

import java.util.Set;

/**
 * A simple implementation of an {@linkplain ObservableBasicMap}.
 *
 */
public class ObservableBasicSetImpl<T> extends AbstractObservableBasicSet<T> {
  /** Backing store for the collection's data. */
  private final Set<T> data = CollectionUtils.newHashSet();

  /**
   * Initializes a new, empty map.
   */
  public ObservableBasicSetImpl() {
  }

  @Override
  public Iterable<T> getValues() {
    return data;
  }

  @Override
  public boolean contains(T value) {
    return data.contains(value);
  }

  @Override
  public void add(T value) {
    boolean added = data.add(value);
    if (added) {
      fireOnValueAdded(value);
    }
  }

  @Override
  public void remove(T value) {
    boolean removed = data.remove(value);
    if (removed) {
      fireOnValueRemoved(value);
    }
  }

  @Override
  public void clear() {
    while (!data.isEmpty()) {
      T value = data.iterator().next();
      remove(value);
    }
  }
}