bundles/org.simantics.equation/src/org/simantics/equation/ext/ElementExpressionSolver.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.equation.ext;\r
  13 \r
  14 import java.util.Iterator;\r
  15 \r
  16 import org.simantics.db.ReadGraph;\r
  17 import org.simantics.db.Resource;\r
  18 import org.simantics.db.common.utils.NameUtils;\r
  19 import org.simantics.db.common.utils.OrderedSetUtils;\r
  20 import org.simantics.db.exception.DatabaseException;\r
  21 import org.simantics.equation.EquationResources;\r
  22 import org.simantics.equation.solver.ExpressionSolver;\r
  23 import org.simantics.equation.solver.Solver;\r
  24 \r
  25 public class ElementExpressionSolver implements ExpressionSolver {\r
  26         \r
  27         private Oper sum = new Sum();\r
  28         private Oper sub = new Sub();\r
  29         private Oper mul = new Mul();\r
  30         private Oper div = new Div();\r
  31         \r
  32         @Override\r
  33         public void evaluate(Solver solver, ReadGraph g, Resource t) throws DatabaseException {\r
  34                 Iterator<Resource> it = OrderedSetUtils.iterator(g, t.get());\r
  35                 double res = getNumber(solver, g, it.next());\r
  36                 while (it.hasNext()) {\r
  37                         Oper op = getOperator(g, it.next());\r
  38                         double v = getNumber(solver, g, it.next());\r
  39                         res = op.evaluate(res, v);\r
  40                 }\r
  41                 \r
  42                 solver.setValue(g.getSingleObject(t, EquationResources.equationResource.HasTarget), new double[]{res});\r
  43         }\r
  44         \r
  45         private double getNumber(Solver solver, ReadGraph g, Resource number) throws DatabaseException {\r
  46                 // TODO : assumes that HasVariable points to Double while it can point to any Property\r
  47                 return solver.getDoubleValue(g, g.getSingleObject(number, EquationResources.equationResource.HasVariable));\r
  48         }\r
  49         \r
  50         private Oper getOperator(ReadGraph g, Resource operator) throws DatabaseException {\r
  51                 if (operator.get().equals(EquationResources.equationResource.Addition))\r
  52                         return sum;\r
  53                 else if (operator.get().equals(EquationResources.equationResource.Subtraction))\r
  54                         return sub;\r
  55                 else if (operator.get().equals(EquationResources.equationResource.Multiplication))\r
  56                         return mul;\r
  57                 else if (operator.get().equals(EquationResources.equationResource.Division))\r
  58                         return div;\r
  59                 throw new RuntimeException("Unknown operation " + NameUtils.getSafeName(g, operator));\r
  60                 \r
  61         }\r
  62         \r
  63         private interface Oper {\r
  64                 double evaluate(double d1, double d2);\r
  65         }\r
  66         \r
  67         private class Sum implements Oper {\r
  68                 @Override\r
  69                 public double evaluate(double d1, double d2) {\r
  70                         return d1 + d2;\r
  71                 }\r
  72         }\r
  73         \r
  74         private class Sub implements Oper {\r
  75                 @Override\r
  76                 public double evaluate(double d1, double d2) {\r
  77                         return d1 - d2;\r
  78                 }\r
  79         }\r
  80         \r
  81         private class Mul implements Oper {\r
  82                 @Override\r
  83                 public double evaluate(double d1, double d2) {\r
  84                         return d1 * d2;\r
  85                 }\r
  86         }\r
  87         \r
  88         private class Div implements Oper {\r
  89                 @Override\r
  90                 public double evaluate(double d1, double d2) {\r
  91                         return d1 / d2;\r
  92                 }\r
  93         }\r
  94         \r
  95         \r
  96 \r
  97 }\r