bundles/org.simantics.databoard/src/org/simantics/databoard/binding/VariantBinding.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;
  13
  14 import java.util.IdentityHashMap;
  15 import java.util.Set;
  16
  17 import org.simantics.databoard.Bindings;
  18 import org.simantics.databoard.Datatypes;
  19 import org.simantics.databoard.accessor.reference.ChildReference;
  20 import org.simantics.databoard.adapter.AdaptException;
  21 import org.simantics.databoard.binding.error.BindingException;
  22 import org.simantics.databoard.binding.error.RuntimeBindingException;
  23 import org.simantics.databoard.binding.impl.BindingPrintContext;
  24 import org.simantics.databoard.binding.impl.ObjectVariantBinding;
  25 import org.simantics.databoard.binding.impl.StringVariantBinding;
  26 import org.simantics.databoard.binding.mutable.ImmutableVariantBinding;
  27 import org.simantics.databoard.binding.mutable.MutableVariant;
  28 import org.simantics.databoard.binding.mutable.MutableVariantBinding;
  29 import org.simantics.databoard.binding.mutable.Variant;
  30 import org.simantics.databoard.type.Datatype;
  31 import org.simantics.databoard.type.VariantType;
  32 import org.simantics.databoard.util.DataValueUtil;
  33 import org.simantics.databoard.util.IdentityPair;
  34
  35 /**
  36  * This is the abstract base class for bindings of VariantType Java Objects.
  37  * Variant is a container that has value of any Datatype.
  38  *
  39  * @see VariantType The Datatype
  40  * @see ImmutableVariantBinding Binds variant to {@link Variant}
  41  * @see MutableVariantBinding Binds variant to {@link MutableVariant}
  42  * @see ObjectVariantBinding Binds variant to java.lang.Object
  43  * @see StringVariantBinding Binds variant to java.lang.String (Filename and URL compatible)
  44  * @author Toni Kalajainen
  45  */
  46 public abstract class VariantBinding extends Binding {
  47
  48         public VariantBinding()
  49         {
  50                 super();
  51                 this.type = Datatypes.VARIANT;
  52         }
  53
  54         /**
  55          * Get the value in the variant. The returned value may represent internal
  56          * value of <code>variant</code>.
  57          *
  58          * @param variant the variant object to read the content from
  59          * @param contentBinding the format of return value
  60          * @return value variant's content
  61          * @throws BindingException
  62          */
  63         public abstract Object getContent(Object variant, Binding contentBinding)
  64         throws BindingException;
  65
  66         /**
  67          * Get the value of the variant. The value is bound with the suggested
  68          * binding, see {@link #getContentBinding(Object)}.
  69          *
  70          * @param variant the variant object
  71          * @return value variant's content
  72          * @throws BindingException
  73          */
  74         public abstract Object getContent(Object variant)
  75         throws BindingException;
  76
  77         /**
  78          * Get the data type of the content.
  79          *
  80          * @param variant the variant object
  81          * @return the data type
  82          * @throws BindingException
  83          */
  84         public abstract Datatype getContentType(Object variant)
  85         throws BindingException;
  86
  87         /**
  88          * Return a suggestion for the binding of the content of this variant.
  89          *
  90          * @param variant variant object
  91          * @return binding a binding
  92          */
  93         public abstract Binding getContentBinding(Object variant)
  94         throws BindingException;
  95
  96         /**
  97          * Create a new variant object.
  98          * The <code>value</code> argument may be included in the result.
  99          *
 100          * @param contentBinding the binding of the content
 101          * @param content content
 102          * @return new variant
 103          * @throws BindingException
 104          */
 105         public abstract Object create(Binding contentBinding, Object content)
 106         throws BindingException;
 107
 108         /**
 109          * Create a new variant object.
 110          *
 111          * @param contentBinding binding of the content
 112          * @param content content
 113          * @return new variant
 114          * @throws RuntimeBindingException
 115          */
 116         public Object createUnchecked(Binding contentBinding, Object content)
 117         throws RuntimeBindingException {
 118                 try {
 119                         return create(contentBinding, content);
 120                 } catch (BindingException e) {
 121                         throw new RuntimeBindingException(e);
 122                 }
 123         }
 124
 125         @Override
 126         public void readFrom(Binding srcBinding, Object src, Object dst)
 127                         throws BindingException {
 128                 try {
 129                         VariantBinding sb = (VariantBinding) srcBinding;
 130                         Datatype newType = sb.getContentType(src);
 131                         Datatype oldType = getContentType(dst);
 132                         Binding scb = sb.getContentBinding(src);
 133                         Object sc = sb.getContent(src, scb);
 134                         if (newType.equals(oldType)) {
 135                                 Binding dcb = getContentBinding(dst);
 136                                 if (dcb.isImmutable()) {
 137                                         Object dc = Bindings.clone(sc, scb, scb);
 138                                         setContent(dst, scb, dc);
 139                                 } else {
 140                                         Object dc = getContent(dst, dcb);
 141                                         dc = dcb.readFromTry(scb, sc, dc);
 142                                         setContent(dst, dcb, dc);
 143                                 }
 144                         } else {
 145                                 Object dc = Bindings.clone(sc, scb, scb);
 146                                 setContent(dst, scb, dc);
 147                         }
 148                 } catch (AdaptException e) {
 149                         throw new BindingException(e);
 150                 }
 151
 152         }
 153
 154         /**
 155          * Set the content of an variant.
 156          *
 157          * @param variant variant object
 158          * @param contentBinding content's binding
 159          * @param content new content
 160          * @throws BindingException
 161          */
 162         public abstract void setContent(Object variant, Binding contentBinding, Object content)
 163         throws BindingException;
 164
 165     @Override
 166     public void accept(Visitor1 v, Object obj) {
 167         v.visit(this, obj);
 168     }
 169
 170     @Override
 171     public <T> T accept(Visitor<T> v) {
 172         return v.visit(this);
 173     }
 174
 175     @Override
 176     public int deepHashValue(Object value, IdentityHashMap<Object, Object> hashedObjects) throws BindingException {
 177                 Datatype type = getContentType(value);
 178                 Binding binding = getContentBinding(value);
 179         Object element = getContent(value, binding);
 180         return Bindings.DATATYPE.deepHashValue(type, hashedObjects) + binding.deepHashValue(element, hashedObjects);
 181     }
 182
 183         @Override
 184         public int deepCompare(Object o1, Object o2,
 185                         Set<IdentityPair<Object, Object>> compareHistory)
 186                         throws BindingException {
 187                 // Compare Type
 188                 Datatype t1 = getContentType(o1);
 189                 Datatype t2 = getContentType(o2);
 190                 int dif = Bindings.DATATYPE.compare(t1, t2);
 191                 if (dif!=0) return dif;
 192                 // Compare Value
 193                 Binding bi1 = getContentBinding(o1);
 194                 Binding bi2 = getContentBinding(o2);
 195                 Object va1 = getContent(o1, bi1);
 196                 Object va2 = getContent(o2, bi2);
 197                 return DataValueUtil.compare(bi1, va1, bi2, va2);
 198         }
 199
 200         @Override
 201         protected void toString(Object value, BindingPrintContext ctx) throws BindingException {
 202                 Binding b = getContentBinding(value);
 203                 b.toString(getContent(value), ctx);
 204
 205                 ctx.b.append(" : ");
 206                 ctx.b.append( ctx.singleLine ? b.type.toSingleLineString() : b.type.toString() );
 207         }
 208
 209         @Override
 210         public Binding getComponentBinding(ChildReference path) {
 211                 if (path==null) return this;
 212                 throw new IllegalArgumentException();
 213         }
 214
 215     @Override
 216     public int getComponentCount() {
 217         return 0;
 218     }
 219
 220     @Override
 221     public Binding getComponentBinding(int index) {
 222         throw new IllegalArgumentException();
 223     }
 224
 225 }
 226