ProviderForMultiMap.java

/*
 * Copyright 2013 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 com.google.gwt.inject.client.multibindings;

import com.google.inject.Inject;
import com.google.inject.Provider;

import java.util.Map;
import java.util.Set;

/**
 * A provider for the multimap of a key&value binding pair.
 *
 * @param <K> type of key for map binding
 * @param <V> type of value for map binding
 */
class ProviderForMultiMap<K, V> implements Provider<Map<K, Set<V>>> {

  @Inject @Internal
  private RuntimeBindingsRegistry<MapEntry<K, V>> registry;

  @Override
  public Map<K, Set<V>> get() {
    SimpleMultimap<K, V> map = new SimpleMultimap<K, V>();
    for (MapEntry<K, V> entry : registry.getBindings()) {
      map.putItem(entry.getKey(), entry.getValueProvider().get());
    }
    return map.toUnmodifiable();
  }
}