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

Go to download
package com.exigen.ie.constrainer.impl;
import com.exigen.ie.constrainer.Constraint;
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.
 */
///////////////////////////////////////////////////////////////////////////////

//
//: ConstraintFloatExpNotValue.java
//
/**
 * An implementation of the constraint: FloatExp != value.
 */
public final class ConstraintFloatExpNotValue extends ConstraintImpl
{
  // PRIVATE MEMBERS
  private FloatExp	 _exp;
  private double     _value;
  private Constraint _opposite;

  public ConstraintFloatExpNotValue(FloatExp exp, double value)
  {
    super(exp.constrainer(),"");//exp.name()+"!="+value);
    _exp = exp;
    _value = value;
  }

  public Goal execute() throws Failure
  {
    class ObserverFloatExpNotValue extends Observer
    {
      public void update(Subject exp, EventOfInterest interest)
        throws Failure
      {
        //Debug.print("ObserverFloatExpNotValue("+_exp+") "+interest);
        FloatEvent event = (FloatEvent)interest;
        double value = (event.min () + event.max ())/2;
        if (FloatCalc.eq (value, _value)){
          constrainer().fail("attempt to set a removed value "+value+" for "+exp);
        }
      }

      public int subscriberMask()
      {
        return  EventOfInterest.VALUE;
      }

      public String toString()
      {
        return "ObserverFloatExpNotValue:"+_exp.name()+"!="+_value;
      }

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

    } //~ ObserverFloatExpNotValue


    //Debug.print("attach ObserverFloatExpNotValue("+_exp+","+_value+")");
    _exp.attachObserver(new ObserverFloatExpNotValue());

    return null;
  }

  public Constraint opposite()
  {
    if (_opposite == null)
      _opposite = new ConstraintFloatExpEqualsValue(_exp,_value);
    return _opposite;
  }

  public IntBoolExp toIntBoolExp(){
    return _exp.ne(_value);
  }

  public String toString()
  {
    return _exp+"!="+_value;
  }

} //~ ConstraintFloatExpNotValue