/* 
    P/P   *  Method: com.dmdirc.util.DoubleMap__static_init
          */
     1  /*
     2   * Copyright (c) 2006-2009 Chris Smith, Shane Mc Cormack, Gregory Holmes
     3   *
     4   * Permission is hereby granted, free of charge, to any person obtaining a copy
     5   * of this software and associated documentation files (the "Software"), to deal
     6   * in the Software without restriction, including without limitation the rights
     7   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     8   * copies of the Software, and to permit persons to whom the Software is
     9   * furnished to do so, subject to the following conditions:
    10   *
    11   * The above copyright notice and this permission notice shall be included in
    12   * all copies or substantial portions of the Software.
    13   *
    14   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    15   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    16   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    17   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    18   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    19   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    20   * SOFTWARE.
    21   */
    22  package com.dmdirc.util;
    23  
    24  import java.util.ArrayList;
    25  import java.util.HashSet;
    26  import java.util.List;
    27  import java.util.Set;
    28  
    29  /**
    30   * An object that maps keys to values, and values back to keys. Currently
    31   * does no checking for duplicates. Does not allow null values.
    32   * 
    33   * @param <A> The first type of data to be mapped
    34   * @param <B> The second type of data to be mapped 
    35   * @author chris
    36   */
         /* 
    P/P   *  Method: void com.dmdirc.util.DoubleMap()
          * 
          *  Postconditions:
          *    this.keys == &amp;new ArrayList(DoubleMap#1)
          *    this.values == &amp;new ArrayList(DoubleMap#2)
          *    new ArrayList(DoubleMap#1) num objects == 1
          *    new ArrayList(DoubleMap#2) num objects == 1
          */
    37  public class DoubleMap<A,B> {
    38      
    39      /** The keys in this map. */
    40      protected final List<A> keys = new ArrayList<A>();
    41      /** The values in this map. */
    42      protected final List<B> values = new ArrayList<B>();
    43      
    44      /**
    45       * Adds the specified pair to this map.
    46       * 
    47       * @param key The key for the map
    48       * @param value The value for the map
    49       */
    50      public void put(final A key, final B value) {
                 /* 
    P/P           *  Method: void put(Object, Object)
                  * 
                  *  Preconditions:
                  *    key != null
                  *    this.keys != null
                  *    this.values != null
                  *    value != null
                  */
    51          if (key == null || value == null) {
    52              throw new NullPointerException();
    53          }
    54          
    55          keys.add(key);
    56          values.add(value);
    57      }
    58      
    59      /**
    60       * Retrieves the value associated with the specified key.
    61       * 
    62       * @param key The key to search for 
    63       * @return The value of the specified key
    64       */
    65      public B getValue(final A key) {
                 /* 
    P/P           *  Method: Object getValue(Object)
                  * 
                  *  Preconditions:
                  *    this.keys != null
                  *    this.values != null
                  * 
                  *  Postconditions:
                  *    init'ed(return_value)
                  */
    66          return values.get(keys.indexOf(key));
    67      }
    68      
    69      /**
    70       * Retrieves the key associated with the specified value.
    71       * 
    72       * @param value The value to search for
    73       * @return The key of the specified value
    74       */
    75      public A getKey(final B value) {
                 /* 
    P/P           *  Method: Object getKey(Object)
                  * 
                  *  Preconditions:
                  *    this.keys != null
                  *    this.values != null
                  * 
                  *  Postconditions:
                  *    init'ed(return_value)
                  */
    76          return keys.get(values.indexOf(value));
    77      }
    78      
    79      /**
    80       * Retrieves the set of keys in this double map.
    81       * 
    82       * @return This map's key set
    83       */
    84      public Set<A> keySet() {
                 /* 
    P/P           *  Method: Set keySet()
                  * 
                  *  Postconditions:
                  *    return_value == &amp;new HashSet(keySet#1)
                  *    new HashSet(keySet#1) num objects == 1
                  */
    85          return new HashSet<A>(keys);
    86      }
    87      
    88      /**
    89       * Retrieves the set of values in this double map.
    90       * 
    91       * @return This map's value set
    92       */
    93      public Set<B> valueSet() {
                 /* 
    P/P           *  Method: Set valueSet()
                  * 
                  *  Postconditions:
                  *    return_value == &amp;new HashSet(valueSet#1)
                  *    new HashSet(valueSet#1) num objects == 1
                  */
    94          return new HashSet<B>(values);
    95      }
    96  
    97  }