bundles/org.simantics.databoard/src/org/simantics/databoard/binding/mutable/MutableVariant.java

   1 /*******************************************************************************\r
   2  *  Copyright (c) 2010 Association for Decentralized Information Management in\r
   3  *  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.databoard.binding.mutable;
  13
  14 import java.io.IOException;\r
  15 import java.io.InputStream;\r
  16 import java.io.InvalidObjectException;\r
  17 import java.io.ObjectStreamException;\r
  18 import java.io.Serializable;\r
  19 \r
  20 import org.simantics.databoard.Accessors;\r
  21 import org.simantics.databoard.Bindings;\r
  22 import org.simantics.databoard.accessor.error.AccessorConstructionException;\r
  23 import org.simantics.databoard.accessor.error.AccessorException;\r
  24 import org.simantics.databoard.accessor.java.JavaObject;\r
  25 import org.simantics.databoard.accessor.reference.ChildReference;\r
  26 import org.simantics.databoard.adapter.AdaptException;\r
  27 import org.simantics.databoard.binding.Binding;\r
  28 import org.simantics.databoard.binding.error.BindingException;\r
  29 import org.simantics.databoard.binding.reflection.VoidBinding;\r
  30 import org.simantics.databoard.type.Datatype;\r
  31
  32 /**
  33  * MutableVariant is a container to a data value of any type.
  34  * The value and type can be changed.
  35  *
  36  * MutableVariant is hash-equals-comparable, even variants of bindings (and types).
  37  * The hash function and comparison rules are defined in the manual.
  38  *\r
  39  * @see MutableVariantBinding is binding for Variant-class
  40  * @author Toni Kalajainen <toni.kalajainen@vtt.fi>
  41  */
  42 public class MutableVariant extends Variant implements Serializable, Cloneable {
  43
  44         private static final long serialVersionUID = 1L;
  45         \r
  46         public static MutableVariant ofInstance(Object instance) {\r
  47                 Binding binding = Bindings.getBindingUnchecked( instance.getClass() );\r
  48                 return new MutableVariant(binding, instance);\r
  49         }\r
  50         \r
  51         /**\r
  52          * Constract a variant with a default value of empty record {}\r
  53          */
  54         public MutableVariant() {\r
  55                 binding = VoidBinding.VOID_BINDING;\r
  56                 value = null;\r
  57         }\r
  58
  59         public MutableVariant(Variant v) {\r
  60 //              assert(isValid(binding, value));\r
  61                 this.binding = v.getBinding();\r
  62                 this.value = v.getValue();\r
  63         }       \r
  64
  65         public MutableVariant(Binding binding, Object value) {
  66 //              assert(isValid(binding, value));
  67                 this.binding = binding;
  68                 this.value = value;
  69         }
  70         \r
  71         /**\r
  72          * Set value and binding from a variant. This method takes the references, \r
  73          * and does not clone the value.\r
  74          * \r
  75          * @param v source variant\r
  76          */
  77         public void setValue(Variant v) {\r
  78                 this.binding = v.getBinding();\r
  79                 this.value = v.getValue();\r
  80         }\r
  81
  82         public void setValue(Binding binding, Object newValue) {
  83 //              assert(isValid(binding, newValue));
  84                 this.binding = binding;
  85                 this.value = newValue;
  86         }\r
  87         \r
  88         public void readFrom(Binding binding, Object newValue) throws BindingException {\r
  89                 if (binding.isImmutable()) {\r
  90                         this.binding = binding;\r
  91                         this.value = newValue;\r
  92                         return;\r
  93                 }\r
  94                                 \r
  95                 if (this.binding == binding) {\r
  96                         binding.readFrom(binding, newValue, this.value);\r
  97                 } else {\r
  98                         try {\r
  99                                 this.value = binding.clone( newValue );\r
 100                                 this.binding = binding;\r
 101                         } catch (AdaptException e) {\r
 102                                 throw new BindingException( e );\r
 103                         }\r
 104                 }\r
 105         }
 106 \r
 107         public MutableVariant clone() {\r
 108                 if (binding.isImmutable()) return new MutableVariant(binding, value);\r
 109                 Object newValue = Bindings.cloneUnchecked(value, binding, binding);\r
 110                 return new MutableVariant(binding, newValue);\r
 111         }\r
 112
 113         private void writeObject(java.io.ObjectOutputStream out) throws IOException {
 114                 Binding dataTypeBinding = Bindings.getBindingUnchecked( Datatype.class );
 115                 Bindings.getSerializerUnchecked( dataTypeBinding ).serialize(type());
 116                 Bindings.getSerializerUnchecked( binding ).serialize(value, out);
 117         }
 118
 119         private void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException {
 120                 Binding dataTypeBinding = Bindings.getBindingUnchecked( Datatype.class );
 121                 Datatype type = (Datatype) Bindings.getSerializerUnchecked( dataTypeBinding ).deserialize((InputStream)in);
 122                 Binding binding = Bindings.getMutableBinding(type);
 123                 Object value = Bindings.getSerializerUnchecked( binding ).deserialize((InputStream)in);
 124                 this.binding = binding;
 125                 this.value = value;
 126         }
 127
 128         @SuppressWarnings("unused")
 129         private void readObjectNoData() throws ObjectStreamException {
 130                 throw new InvalidObjectException("Don't know how to instantiate "+type()+" with no data");
 131         }
 132
 133         public MutableVariant getComponent(ChildReference ref) throws AccessorConstructionException {\r
 134                 if ( ref == null ) return this;\r
 135                 JavaObject jo = (JavaObject) Accessors.getAccessor(this, ref);\r
 136                 return new MutableVariant( jo.getBinding(), jo.getObject() );\r
 137         }\r
 138         \r
 139         public void setComponent(ChildReference ref, Binding binding, Object value) throws AccessorException, AccessorConstructionException {\r
 140         if ( ref == null ) {\r
 141             setValue( binding, value );\r
 142         }\r
 143         else {\r
 144             JavaObject jo = (JavaObject) Accessors.getAccessor(this, ref);\r
 145             jo.setValue( ref, binding, value );\r
 146         }\r
 147         }\r
 148 }