com.exigen.ie.constrainer.impl.ConstraintFloatExpEqualsExp Maven / Gradle / Ivy

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package com.exigen.ie.constrainer.impl;
import com.exigen.ie.constrainer.ConstraintImpl;
import com.exigen.ie.constrainer.EventOfInterest;
import com.exigen.ie.constrainer.Failure;
import com.exigen.ie.constrainer.FloatEvent;
import com.exigen.ie.constrainer.FloatExp;
import com.exigen.ie.constrainer.Goal;
import com.exigen.ie.constrainer.IntBoolExp;
import com.exigen.ie.constrainer.Observer;
import com.exigen.ie.constrainer.Subject;

///////////////////////////////////////////////////////////////////////////////
/*
 * Copyright Exigen Group 1998, 1999, 2000
 * 320 Amboy Ave., Metuchen, NJ, 08840, USA, www.exigengroup.com
 *
 * The copyright to the computer program(s) herein
 * is the property of Exigen Group, USA. All rights reserved.
 * The program(s) may be used and/or copied only with
 * the written permission of Exigen Group
 * or in accordance with the terms and conditions
 * stipulated in the agreement/contract under which
 * the program(s) have been supplied.
 */
///////////////////////////////////////////////////////////////////////////////

/**
 * An implementation of the constraint: FloatExp1 == FloatExp2 + offset.
 */
public final class ConstraintFloatExpEqualsExp extends ConstraintImpl
{
  // PRIVATE MEMBERS
  private FloatExp	_exp1;
  private FloatExp	_exp2;
  private double    _offset;

  public ConstraintFloatExpEqualsExp(FloatExp exp1, FloatExp exp2)
  {
    this(exp1,exp2,0d);
  }

  /**
   * exp1 == exp2 + offset
   */
  public ConstraintFloatExpEqualsExp(FloatExp exp1, FloatExp exp2, double offset)
  {
    super(exp1.constrainer());
    _exp1 = exp1;
    _exp2 = exp2;
    _offset = offset;

    if (constrainer().showInternalNames())
    {
      if(offset == 0)
        _name = "(" + exp1.name() + "=" + exp2.name() + ")";
      else if(offset>0)
        _name = "(" + exp1.name() + "=" + exp2.name() + "+" + offset + ")";
      else
        _name = "(" + exp1.name() + "=" + exp2.name() + offset + ")";
    }
  }


    class ObserverFloatEqual extends Observer
    {
      public void update(Subject exp, EventOfInterest interest)
        throws Failure
      {
        //Debug.on();Debug.print("ObserverFloatEqual: "+_name+" Event: "+interest);Debug.off();
        FloatEvent event = (FloatEvent)interest;
//        if (event.isRemoveEvent())
//        {
//          int max = event.numberOfRemoves();
//          for(int i =0; i < max; ++i)
//          {
//            if (exp == _exp1)
//              _exp2.removeValue(event.removed(i)-_offset);
//            else
//            if (exp == _exp2)
//              _exp1.removeValue(event.removed(i)+_offset);
//          }
//        }
//        else
        {
            minmax();
        }
      }

    public int subscriberMask()
    {
       return EventOfInterest.MINMAX;// | EventOfInterest.REMOVE;
    }

    public String toString()
    {
      return _name+"(ObserverFloatEqual)";
    }

    public Object master()
    {
      return ConstraintFloatExpEqualsExp.this;
    }

  } //~ ObserverFloatEqual

  public Goal execute() throws Failure
  {
    minmax(); // may fail
    ObserverFloatEqual observer = new ObserverFloatEqual();
    _exp1.attachObserver(observer);
    _exp2.attachObserver(observer);
    return null;
  }

  public void minmax() throws Failure
  {
    _exp1.setMax(_exp2.max()+_offset); // may fail
    _exp2.setMax(_exp1.max()-_offset); // may fail
    _exp1.setMin(_exp2.min()+_offset); // may fail
    _exp2.setMin(_exp1.min()-_offset); // may fail
  }

  public boolean isLinear(){
    return (_exp1.isLinear() && _exp2.isLinear());
  }

  public IntBoolExp toIntBoolExp(){
    return _exp1.eq(_exp2.add(_offset));
  }

  public String toString()
  {
    return _exp1+"="+_exp2;
  }

} //~ ConstraintFloatExpEqualsExp