bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/SetUnion.java

   1 /*******************************************************************************\r
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
   3  * in Industry THTH ry.\r
   4  * All rights reserved. This program and the accompanying materials\r
   5  * are made available under the terms of the Eclipse Public License v1.0\r
   6  * which accompanies this distribution, and is available at\r
   7  * http://www.eclipse.org/legal/epl-v10.html\r
   8  *\r
   9  * Contributors:\r
  10  *     VTT Technical Research Centre of Finland - initial API and implementation\r
  11  *******************************************************************************/\r
  12 package org.simantics.utils.datastructures;\r
  13 \r
  14 import java.util.Collection;\r
  15 import java.util.Iterator;\r
  16 import java.util.Set;\r
  17 \r
  18 public class SetUnion<T> extends ImmutableCollection<T> {\r
  19 \r
  20     private Set<T> set1;\r
  21     private Set<T> set2;    \r
  22     \r
  23     public SetUnion(Set<T> set1, Set<T> set2) {\r
  24         this.set1 = set1;\r
  25         this.set2 = set2;\r
  26     }\r
  27 \r
  28     @Override\r
  29     public boolean contains(Object o) {\r
  30         return set1.contains(o) || set2.contains(o);\r
  31     }\r
  32 \r
  33     @Override\r
  34     public boolean containsAll(Collection<?> c) {\r
  35         for(Object o : c)\r
  36             if(!contains(o))\r
  37                 return false;\r
  38         return true;\r
  39     }\r
  40 \r
  41     @Override\r
  42     public boolean isEmpty() {\r
  43         return set1.isEmpty() && set2.isEmpty();\r
  44     }\r
  45 \r
  46     @Override\r
  47     public Iterator<T> iterator() {\r
  48         return new ImmutableIterator<T>() {\r
  49 \r
  50             int setId = 0;\r
  51             Iterator<T> it1 = set1.iterator();\r
  52             Iterator<T> it2 = set2.iterator();\r
  53             T element = null;\r
  54             \r
  55             @Override\r
  56             public boolean hasNext() {\r
  57                 if(setId == 0) {\r
  58                     if(it1.hasNext())\r
  59                         return true;\r
  60                     else {\r
  61                         setId = 1;\r
  62                         return hasNext();\r
  63                     }\r
  64                 }\r
  65                 else {\r
  66                     if(element != null)\r
  67                         return true;\r
  68                     while(it2.hasNext()) {                            \r
  69                         element = it2.next();\r
  70                         if(set1.contains(element)) \r
  71                             element = null;\r
  72                         else\r
  73                             return true;\r
  74                     }\r
  75                     return false;\r
  76                 }\r
  77             }\r
  78 \r
  79             @Override\r
  80             public T next() {\r
  81                 if(setId == 0) {\r
  82                     if(it1.hasNext())\r
  83                         return it1.next();\r
  84                     else {\r
  85                         setId = 1;\r
  86                         return next();\r
  87                     }\r
  88                 }\r
  89                 else {\r
  90                     if(element != null) {\r
  91                         T ret = element;\r
  92                         element = null;\r
  93                         return ret;\r
  94                     }\r
  95                     while(it2.hasNext()) {                            \r
  96                         T ret = it2.next();\r
  97                         if(!set1.contains(ret)) \r
  98                             return ret;\r
  99                     }\r
 100                     return null;\r
 101                 }\r
 102             }\r
 103             \r
 104         };\r
 105     }\r
 106 \r
 107     @Override\r
 108     public int size() {\r
 109         int count = set1.size();       \r
 110         for(T o : set2)\r
 111             if(!set1.contains(o))\r
 112                 ++count;\r
 113         return count;\r
 114     }       \r
 115     \r
 116 }\r