java/dagger/internal/MapProviderFactory.java

/*
 * Copyright (C) 2014 The Dagger 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 dagger.internal;

import dagger.Lazy;
import java.util.Map;
import javax.inject.Provider;

/**
 * A {@link Factory} implementation used to implement {@link Map} bindings. This factory returns a
 * {@code Map<K, Provider<V>>} when calling {@link #get} (as specified by {@link Factory}).
 */
public final class MapProviderFactory<K, V> extends AbstractMapFactory<K, V, Provider<V>>
    implements Lazy<Map<K, Provider<V>>> {

  /** Returns a new {@link Builder} */
  public static <K, V> Builder<K, V> builder(int size) {
    return new Builder<>(size);
  }

  private MapProviderFactory(Map<K, Provider<V>> contributingMap) {
    super(contributingMap);
  }

  /**
   * Returns a {@code Map<K, Provider<V>>} whose iteration order is that of the elements given by
   * each of the providers, which are invoked in the order given at creation.
   */
  @Override
  public Map<K, Provider<V>> get() {
    return contributingMap();
  }

  /** A builder for {@link MapProviderFactory}. */
  public static final class Builder<K, V> extends AbstractMapFactory.Builder<K, V, Provider<V>> {
    private Builder(int size) {
      super(size);
    }

    @Override
    public Builder<K, V> put(K key, Provider<V> providerOfValue) {
      super.put(key, providerOfValue);
      return this;
    }

    @Override
    public Builder<K, V> putAll(Provider<Map<K, Provider<V>>> mapProviderFactory) {
      super.putAll(mapProviderFactory);
      return this;
    }

    /** Returns a new {@link MapProviderFactory}. */
    public MapProviderFactory<K, V> build() {
      return new MapProviderFactory<>(map);
    }
  }
}