// This example is from the book Developing Java Beans by Robert Englander. 
// Copyright (c) 1997 O'Reilly & Associates.
// You may study, use, modify, and distribute this example for any purpose.
// This example is provided WITHOUT WARRANTY either expressed or implied.

// Chapter 8 -- The Cooler class

package BeansBook.Simulator;

import java.awt.*;
import java.beans.*;

// the Cooler bean class definition
public class Cooler extends TemperatureModifier
   implements CoolingRequestListener, VetoableChangeListener
{
   // constructor
   public Cooler()
   {
      // a cooler is a temperature modifier that operates at
      // 0 degress celsius
      super(0.0, "COOLER ON", "COOLER OFF",
               Color.cyan, Color.yellow);
   }

   // handle a cooling request event
   public void coolingRequest(ServiceRequestEvent evt)
   {
     // set the Running property based on the value returned
     // by the isStart method from the event
     setRunning(evt.isStart());
   }

   // handle a vetoable change event
   public void vetoableChange(PropertyChangeEvent evt)
           throws PropertyVetoException
   {
      // only interested in ComfortTemperature
      if (evt.getPropertyName().equals("ComfortTemperature"))
      {
         // get the proposed temperature
         Double d = (Double)evt.getNewValue();
 
         // veto a temperature under 0 degrees Celsius
         if (d.doubleValue() < 0.0)
         {
            throw new PropertyVetoException("Invalid Comfort Temperature", evt);
         }
      }
   }
}