bundles/org.simantics.databoard/src/org/simantics/databoard/binding/util/DefaultValueWithCache.java

   1 /*******************************************************************************
   2  *  Copyright (c) 2010 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.databoard.binding.util;
  13
  14 import java.util.Map;
  15 import java.util.WeakHashMap;
  16
  17 import org.simantics.databoard.Bindings;
  18 import org.simantics.databoard.binding.ArrayBinding;
  19 import org.simantics.databoard.binding.Binding;
  20 import org.simantics.databoard.binding.Binding.Visitor;
  21 import org.simantics.databoard.binding.BooleanBinding;
  22 import org.simantics.databoard.binding.ByteBinding;
  23 import org.simantics.databoard.binding.DoubleBinding;
  24 import org.simantics.databoard.binding.FloatBinding;
  25 import org.simantics.databoard.binding.IntegerBinding;
  26 import org.simantics.databoard.binding.LongBinding;
  27 import org.simantics.databoard.binding.MapBinding;
  28 import org.simantics.databoard.binding.OptionalBinding;
  29 import org.simantics.databoard.binding.RecordBinding;
  30 import org.simantics.databoard.binding.StringBinding;
  31 import org.simantics.databoard.binding.UnionBinding;
  32 import org.simantics.databoard.binding.VariantBinding;
  33 import org.simantics.databoard.binding.error.BindingException;
  34 import org.simantics.databoard.binding.error.RuntimeBindingException;
  35 import org.simantics.databoard.type.ArrayType;
  36 import org.simantics.databoard.type.ByteType;
  37 import org.simantics.databoard.type.DoubleType;
  38 import org.simantics.databoard.type.FloatType;
  39 import org.simantics.databoard.type.IntegerType;
  40 import org.simantics.databoard.type.LongType;
  41 import org.simantics.databoard.type.StringType;
  42 import org.simantics.databoard.util.Range;
  43
  44 /**
  45  * Visitor that creates a default instance of a DataType.
  46  * This visitor may throw RuntimeBindingException.
  47  *
  48  * Type                     Value
  49  * ------------------------------------------------------
  50  * Boolean                  false
  51  * Byte, Integer, Long      0 or min limit
  52  * Float, Double            0.0 or min limit
  53  * String                   ""
  54  * Optional                 *novalue*
  55  * Union                    tag 0
  56  * Record                   each field with default value
  57  * Array                    min range number of elements
  58  * Map                      no entries
  59  * Variant                  {} : void
  60  *
  61  *
  62  * TODO Create String according to the pattern
  63  * @author Toni Kalajainen <toni.kalajainen@vtt.fi>
  64  */
  65 public class DefaultValueWithCache implements Visitor<Object> {
  66
  67         /** Map of default values already created. Used to link back to recursive records */
  68         Map<Binding, Object> map = new WeakHashMap<Binding, Object>(1);
  69
  70         @Override
  71         public Object visit(ArrayBinding b) {
  72                 Object result = map.get(b);
  73                 if (result!=null) return result;
  74
  75                 ArrayType at = b.type();
  76                 Range r = at.getLength();
  77                 int min = (r!=null) ? r.getLower().getValue().intValue() : 0;
  78
  79                 if (min>0) {
  80                         Binding componentBinding = b.getComponentBinding();
  81                         Object[] array = new Object[min];
  82                         for (int i=0; i<min; i++) {
  83                                 array[i] = componentBinding.accept(this);
  84                         }
  85                         result = b.createUnchecked(array);
  86                 } else {
  87                         result = b.createUnchecked();
  88                 }
  89                 map.put(b, result);
  90                 return result;
  91         }
  92
  93         @Override
  94         public Object visit(BooleanBinding b) {
  95                 Object result = map.get(b);
  96                 if (result!=null) return result;
  97                 result = b.createUnchecked(Boolean.FALSE);
  98                 map.put(b, result);
  99                 return result;
 100         }
 101
 102         @Override
 103         public Object visit(DoubleBinding b) {
 104                 Object result = map.get(b);
 105                 if (result!=null) return result;
 106                 DoubleType type = b.type();
 107                 Range range = type.getRange();
 108                 double value = (range==null) ? 0.0 : range.getLower().getValue().doubleValue();
 109                 result = b.createUnchecked(value);
 110                 map.put(b, result);
 111                 return result;
 112         }
 113
 114         @Override
 115         public Object visit(FloatBinding b) {
 116                 Object result = map.get(b);
 117                 if (result!=null) return result;
 118                 FloatType type = b.type();
 119                 Range range = type.getRange();
 120                 float value = (range==null) ? 0.f : range.getLower().getValue().floatValue();
 121                 result = b.createUnchecked(value);
 122                 map.put(b, result);
 123                 return result;
 124         }
 125
 126         @Override
 127         public Object visit(IntegerBinding b) {
 128                 Object result = map.get(b);
 129                 if (result!=null) return result;
 130                 IntegerType type = b.type();
 131                 Range range = type.getRange();
 132                 int value = (range==null) ? 0 : range.getLower().getValue().intValue();
 133                 result = b.createUnchecked(value);
 134                 map.put(b, result);
 135                 return result;
 136         }
 137
 138         @Override
 139         public Object visit(ByteBinding b) {
 140                 Object result = map.get(b);
 141                 if (result!=null) return result;
 142                 ByteType type = b.type();
 143                 Range range = type.getRange();
 144                 byte value = (range==null) ? 0 : range.getLower().getValue().byteValue();
 145                 result = b.createUnchecked(value);
 146                 map.put(b, result);
 147                 return result;
 148         }
 149
 150         @Override
 151         public Object visit(LongBinding b) {
 152                 Object result = map.get(b);
 153                 if (result!=null) return result;
 154                 LongType type = b.type();
 155                 Range range = type.getRange();
 156                 long value = (range==null) ? 0 : range.getLower().getValue().longValue();
 157                 result = b.createUnchecked(value);
 158                 map.put(b, result);
 159                 return result;
 160         }
 161
 162         @Override
 163         public Object visit(OptionalBinding b) {
 164                 Object result = map.get(b);
 165                 if (result!=null) return result;
 166                 result = b.createNoValueUnchecked();
 167                 map.put(b, result);
 168                 return result;
 169         }
 170
 171         @Override
 172         public Object visit(RecordBinding b) {
 173                 try {
 174                         Object result = map.get(b);
 175                         if (result!=null) return result;
 176                         Object[] values = new Object[ b.getComponentCount() ];
 177                         result = b.createPartial();
 178                         map.put(b, result);
 179                         for (int i=0; i<values.length; i++) {
 180                                 Binding cb = b.getComponentBinding(i);
 181                                 values[i] = cb.accept(this);
 182                         }
 183                         b.setComponents(result, values);
 184                         return result;
 185                 } catch (BindingException e) {
 186                         throw new RuntimeBindingException(e);
 187                 }
 188         }
 189
 190         @Override
 191         public Object visit(StringBinding b) {
 192                 Object result = map.get(b);
 193                 if (result!=null) return result;
 194                 StringType st = b.type();
 195                 if (st.getPattern() != null) {
 196                         // TODO Create a string that is valid to the pattern
 197                         result = b.createUnchecked("");
 198                 } else {
 199                         result = b.createUnchecked("");
 200                 }
 201                 map.put(b, result);
 202                 return result;
 203         }
 204
 205         @Override
 206         public Object visit(UnionBinding b) {
 207                 Object result = map.get(b);
 208                 if (result!=null) return result;
 209                 int tag = 0;
 210                 Binding componentBinding = b.getComponentBinding(tag);
 211                 Object tag0defaultValue = componentBinding.accept(this);
 212                 result = b.createUnchecked(tag, tag0defaultValue);
 213                 map.put(b, result);
 214                 return result;
 215         }
 216
 217
 218         @Override
 219         public Object visit(VariantBinding b) {
 220                 Object result = map.get(b);
 221                 if (result!=null) return result;
 222                 Binding voidBinding = Bindings.getBindingUnchecked(void.class);
 223                 Object voidValue = null;
 224                 result = b.createUnchecked(voidBinding, voidValue);
 225                 map.put(b, result);
 226                 return result;
 227         }
 228
 229         @Override
 230         public Object visit(MapBinding b) {
 231                 Object result = map.get(b);
 232                 if (result!=null) return result;
 233                 result = b.createUnchecked();
 234                 map.put(b, result);
 235                 return result;
 236         }
 237
 238 }
 239