/* Temperature2.java (child class of Temperature)
** An instance of this class has all the capabilities of an instance of its
** parent class, but in addition supports expressing temperatures (and 
** temperature changes) in terms of Fahrenheit degrees. 
**
** Author: R. McCloskey and < STUDENTS' NAMES >
*/

public class Temperature2 extends Temperature {

   // instance variables
   // ------------------

   // None!


   // constructor
   // -----------

   /* Initializes this Temperature to be the specified # of degrees,
   ** where that measure is to be interpreted to be on the Celsius scale if
   ** the 2nd parameter is true but on the Fahrenheit scale if it is false.
   */
   public Temperature2(double degrees, boolean inCelsius) {
      // STUB!!
   }


   // observer
   // --------

   /* Returns this Temperature2's value as expressed on the Fahrenheit scale.
   */
   public double degreesFahrenheit() {
      return 0;  // STUB!!
   }


   // mutators
   // --------

   /* Sets this Temperature2 object to the specified number of degrees on
   ** the Fahrenheit scale.
   */
   public void setToFah(double fahDeg) { 
      // STUB!
   }

   /* Changes this Temperature2 object by the specified number 
   ** of Fahrenheit degrees.
   */
   public void changeByFah(double fahDelta) {
      // STUB!
   }


   // private stuff 
   // -------------

   // constants
   // ---------

   // The ratios describing changes in a temperature reading on the Celsius
   // scale vs. that on the Fahrenheit scale.  (A change of five degrees
   // Celsius corresponds to a change of nine degrees Fahrenheit.)
   private static final double CEL_TO_FAH_RATIO = 5.0 / 9.0;
   private static final double FAH_TO_CEL_RATIO = 9.0 / 5.0;

   // The Fahrenheit temperature at which ice melts.
   private static final double FAH_MELTING_POINT = 32.0;

   // methods
   // -------

   /* Given a change in temperature as measured on the Fahrenheit scale,
   ** returns the corresponding change as measured on the Celsius scale.
   ** E.g., a change of 18 degrees on the Fahrenheit scale corresponds
   ** to a change of 10 degrees on the Celsius scale.
   */
   private double fahDeltaToCelDelta(double fahDelta) {
      return CEL_TO_FAH_RATIO * fahDelta;
   }

   /* Returns the equivalent, on the Celsius scale, of a temperature 
   ** reading on the Fahrenheit scale.  E.g., a Fahrenheit temperature
   ** of 68 degrees corresponds to 20 degrees Celsius.
   */
   private double fahToCel(double fahDeg) {
      return CEL_TO_FAH_RATIO * (fahDeg - FAH_MELTING_POINT);
   }

   /* Returns the equivalent, on the Fahrenheit scale, of a temperature 
   ** reading on the Celsius scale.  E.g., a Celsius temperature of 25 
   ** degrees corresponds to 77 degrees Fahrenheit.
   */
   private double celToFah(double celDeg) {
      return (FAH_TO_CEL_RATIO * celDeg) + FAH_MELTING_POINT;
   }

}