bundles/org.simantics.objmap2/src/org/simantics/objmap/graph/rules/range/ListAccessor.java

   1 /*******************************************************************************
   2  * Copyright (c) 2012, 2013 Association for Decentralized Information Management in
   3  * Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.objmap.graph.rules.range;
  13
  14 import java.lang.reflect.InvocationTargetException;
  15 import java.lang.reflect.Method;
  16 import java.util.ArrayList;
  17 import java.util.Collection;
  18
  19 import org.simantics.objmap.exceptions.MappingException;
  20 import org.simantics.utils.datastructures.Pair;
  21
  22
  23 /**
  24  * Accessor for mapped collections.
  25  * Uses three methods:
  26  * - Getter: returns the collection.
  27  * - Adder: adds one item into the collection.
  28  * - Remover: removes one item from the collection.
  29  *
  30  * @author Marko Luukkainen <marko.luukkainen@vtt.fi>
  31  *
  32  * @param <T>
  33  */
  34 public class ListAccessor<Range,T>  implements IRangeAccessor<Range,Collection<T>> {
  35
  36         private Method getter;
  37         private Method adder;
  38         private Method remover;
  39
  40         public ListAccessor(Method getter, Method adder, Method remover) {
  41                 this.getter = getter;
  42                 this.adder = adder;
  43                 this.remover = remover;
  44         }
  45
  46         @SuppressWarnings("unchecked")
  47         public java.util.Collection<T> get(Object element) throws MappingException {
  48                 try {
  49                         return (Collection<T>) getter.invoke(element);
  50                 } catch (IllegalArgumentException e) {
  51                         throw new MappingException(e);
  52                 } catch (IllegalAccessException e) {
  53                         throw new MappingException(e);
  54                 } catch (InvocationTargetException e) {
  55                         throw new MappingException(e.getCause());
  56                 }
  57         };
  58
  59         @Override
  60         public boolean set(Range element, Collection<T> value)
  61                         throws MappingException {
  62                 java.util.Collection<T> current = get(element);
  63                 Collection<Pair<Integer, T>> adding = new ArrayList<Pair<Integer, T>>();
  64                 Collection<T> removing = new ArrayList<T>();
  65                 for (T e : current) {
  66                         if (!value.contains(e))
  67                                 removing.add(e);
  68                 }
  69                 int i = 0;
  70                 for (T e : value) {
  71                         if (!current.contains(e))
  72                                 adding.add(new Pair<Integer, T>(i, e));
  73                         i++;
  74                 }
  75
  76                 try {
  77                         for (T e : removing) {
  78                                 remover.invoke(element, e);
  79                         }
  80
  81                         for (Pair<Integer,T> e : adding) {
  82                                 adder.invoke(element, e.first,e.second);
  83                         }
  84                 } catch (IllegalArgumentException e) {
  85                         throw new MappingException(e);
  86                 } catch (IllegalAccessException e) {
  87                         throw new MappingException(e);
  88                 } catch (InvocationTargetException e) {
  89                         throw new MappingException(e.getCause());
  90                 }
  91                 return removing.size() > 0 || adding.size() > 0;
  92
  93         }
  94 }