bundles/org.simantics.equation/src/org/simantics/equation/ext/ElementExpressionSolver.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in 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.equation.ext;
  13
  14 import java.util.Iterator;
  15
  16 import org.simantics.db.ReadGraph;
  17 import org.simantics.db.Resource;
  18 import org.simantics.db.common.utils.NameUtils;
  19 import org.simantics.db.common.utils.OrderedSetUtils;
  20 import org.simantics.db.exception.DatabaseException;
  21 import org.simantics.equation.EquationResources;
  22 import org.simantics.equation.solver.ExpressionSolver;
  23 import org.simantics.equation.solver.Solver;
  24
  25 public class ElementExpressionSolver implements ExpressionSolver {
  26
  27         private Oper sum = new Sum();
  28         private Oper sub = new Sub();
  29         private Oper mul = new Mul();
  30         private Oper div = new Div();
  31
  32         @Override
  33         public void evaluate(Solver solver, ReadGraph g, Resource t) throws DatabaseException {
  34                 Iterator<Resource> it = OrderedSetUtils.iterator(g, t.get());
  35                 double res = getNumber(solver, g, it.next());
  36                 while (it.hasNext()) {
  37                         Oper op = getOperator(g, it.next());
  38                         double v = getNumber(solver, g, it.next());
  39                         res = op.evaluate(res, v);
  40                 }
  41
  42                 solver.setValue(g.getSingleObject(t, EquationResources.equationResource.HasTarget), new double[]{res});
  43         }
  44
  45         private double getNumber(Solver solver, ReadGraph g, Resource number) throws DatabaseException {
  46                 // TODO : assumes that HasVariable points to Double while it can point to any Property
  47                 return solver.getDoubleValue(g, g.getSingleObject(number, EquationResources.equationResource.HasVariable));
  48         }
  49
  50         private Oper getOperator(ReadGraph g, Resource operator) throws DatabaseException {
  51                 if (operator.get().equals(EquationResources.equationResource.Addition))
  52                         return sum;
  53                 else if (operator.get().equals(EquationResources.equationResource.Subtraction))
  54                         return sub;
  55                 else if (operator.get().equals(EquationResources.equationResource.Multiplication))
  56                         return mul;
  57                 else if (operator.get().equals(EquationResources.equationResource.Division))
  58                         return div;
  59                 throw new RuntimeException("Unknown operation " + NameUtils.getSafeName(g, operator));
  60
  61         }
  62
  63         private interface Oper {
  64                 double evaluate(double d1, double d2);
  65         }
  66
  67         private class Sum implements Oper {
  68                 @Override
  69                 public double evaluate(double d1, double d2) {
  70                         return d1 + d2;
  71                 }
  72         }
  73
  74         private class Sub implements Oper {
  75                 @Override
  76                 public double evaluate(double d1, double d2) {
  77                         return d1 - d2;
  78                 }
  79         }
  80
  81         private class Mul implements Oper {
  82                 @Override
  83                 public double evaluate(double d1, double d2) {
  84                         return d1 * d2;
  85                 }
  86         }
  87
  88         private class Div implements Oper {
  89                 @Override
  90                 public double evaluate(double d1, double d2) {
  91                         return d1 / d2;
  92                 }
  93         }
  94
  95
  96
  97 }