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

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package com.exigen.ie.constrainer.impl;
import com.exigen.ie.constrainer.EventOfInterest;
import com.exigen.ie.constrainer.Failure;
import com.exigen.ie.constrainer.IntExp;
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 expression: IntExp⁺.
 * The domain of the IntExpPositive has only non-negative part
 * ([o..max])of the domain of the IntExp.
 */
public final class IntExpPositive extends IntExpImpl
{
  private IntExp	           _exp;
  private ExpressionObserver _observer;

  class ExpPositiveObserver extends ExpressionObserver
  {
       public void update(Subject subject, EventOfInterest event)
                      throws Failure
      {
      }


      public String toString()
      {
        return "ExpPositiveObserver: "+_exp;
      }

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


  } //~ ExpAddValueObserver


  public IntExpPositive(IntExp exp)
  {
    super(exp.constrainer(),"");//exp.name()+"+"+value);
    _exp = exp;
    _observer = new ExpPositiveObserver();
    _exp.attachObserver(_observer);
  }

  public void onMaskChange()
  {
    _observer.publish(publisherMask(),_exp);
  }

  public boolean contains(int value)
  {
    return value >= 0 && _exp.contains(value);
  }

  public int max()
  {
    int max = _exp.max();
    return max >= 0 ? max : MIN_VALUE;
  }

  public int min()
  {
    int min = _exp.min();
    return min > 0 ? min : 0;
  }

  public void setMax(int max) throws Failure
  {
    _exp.setMax(max);
  }

  public void setMin(int min) throws Failure
  {
    if (_exp.min() >= 0)
      _exp.setMin(min);
  }

  public void setValue(int value) throws Failure
  {
    _exp.setValue(value);
  }

  public void removeValue(int value) throws Failure
  {
    if (value >= 0)
      _exp.removeValue(value);
  }

  public int size()
  {
    if (!valid())
      return 0;

    return Math.min(_exp.size(), _exp.max() + 1);
  }

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

  public int value() throws Failure
  {
    if (!bound())
      constrainer().fail("Attempt to get value of the unbound expression "+this);
    return _exp.value();
  }

  public boolean valid()
  {
    return _exp.min() >= 0;
  }

} //eof IntExpImpl