content: /*
   * Copyright (C) 2016 The Android Open Source Project
   *
   * 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.android.launcher3.util;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  
  /**
   * A utility map from keys to an ArrayList of values.
   */
  public class MultiHashMap<K, V> extends HashMap<K, ArrayList<V>> {
  
      public MultiHashMap() { }
  
      public MultiHashMap(int size) {
          super(size);
      }
  
      public void addToList(K key, V value) {
          ArrayList<V> list = get(key);
          if (list == null) {
              list = new ArrayList<>();
              list.add(value);
              put(key, list);
          } else {
              list.add(value);
          }
      }
  
      @Override
      public MultiHashMap<K, V> clone() {
          MultiHashMap<K, V> map = new MultiHashMap<>(size());
          for (Entry<K, ArrayList<V>> entry : entrySet()) {
              map.put(entry.getKey(), new ArrayList<V>(entry.getValue()));
          }
          return map;
      }
  }
  