import java.awt.*;

/**
 *	Param.java:	A generic parameter class for use in my engineering programs.
 *
 *	Written in:	Java 1.0.2
 *
 *	@author		Joseph A. Huwaldt	Date:	November 23, 1997
 *	@author		Joseph A. Huwaldt	Date:	November 30, 1997
 *	@version	December 2, 1997
 **/
class Param extends Object {
	private float	theValue;		//	The value of this parameter.
	private boolean	defined;		//	Is this parameter defined?
	private String	labelStr;		//	String containing a lable for this parameter.
	

	/**
	* Param():	Param object constructor #1.
	*			Takes a label string and sets parameter to an initial value of Float.NaN.
	*
	*	Written by:		Joseph A. Huwaldt		Date:	November 23, 1997
	*	Modified by:	Joseph A. Huwaldt		Date:	November 30, 1997
	*
	*	@param		label	The label to be attached to this object.
	*	@return		No return value
	**/
	Param(String label) {
		labelStr = label;
		theValue = Float.NaN;
		defined = false;
	}

	/**
	* Param():	Param object constructor #2.
	*			Takes a label string and a float value for the parameter.
	*
	*	Written by:		Joseph A. Huwaldt		Date:	November 23, 1997
	*	Modified by:	Joseph A. Huwaldt		Date:	November 30, 1997
	*
	*	@param		label	The label to be attached to this object.
	*	@param		value	The initial value for the parameter to hold.
	*	@return		No return value
	**/
	Param(String label, float value) {
		labelStr = label;
		theValue = value;
		defined = true;
	}

	/**
	* Param():	Param object constructor #3.
	*			Takes a label string and a value in string form for the parameter.
	*
	*	Written by:		Joseph A. Huwaldt		Date:	November 23, 1997
	*	Modified by:	Joseph A. Huwaldt		Date:	November 30, 1997
	*
	*	@param		label	The label to be attached to this object.
	*	@param		value	The initial value for the parameter to hold.
	*	@return		No return value
	*	@exception	NumberFormatException	Thrown if value string can't be converted to a float.
	**/
	Param(String label, String value) throws NumberFormatException {
		labelStr = label;
		if (value.equals("")) {
			defined = false;
			theValue = Float.NaN;
		} else {
			theValue = Float.valueOf(value).floatValue();
			if (theValue != Float.NaN)
				defined = true;
			else
				defined = false;
		}
	}
	

	/**
	* getValue():	Method to return the value of this parameter.
	*
	*	Written by:		Joseph A. Huwaldt		Date:	November 23, 1997
	*	Modified by:	Joseph A. Huwaldt		Date:	November 23, 1997
	*
	*	@param		No parameter.
	*	@return		The float value of this parameter is returned.
	**/
	public float getValue() {
		return theValue;
	}


	/**
	* setValue():	Method to set the value of this parameter.  Makes the parameter
	*				"defined".
	*
	*	Written by:		Joseph A. Huwaldt		Date:	November 23, 1997
	*	Modified by:	Joseph A. Huwaldt		Date:	November 29, 1997
	*
	*	@param	value	The value that the parameter object should be set to.
	*	@return	No return value
	**/
	public void setValue(float value) {
		theValue = value;
		if (value != Float.NaN)
			defined = true;
		else
			defined = false;
	}

	/**
	* setValue():	Method to set the value of this parameter using string input.
	*				Makes this parameter "defined".
	*
	*	Written by:		Joseph A. Huwaldt		Date:	November 23, 1997
	*	Modified by:	Joseph A. Huwaldt		Date:	November 29, 1997
	*
	*	@param	value	The value that the parameter object should be set to.
	*	@return	No return value
	*	@exception	NumberFormatException	Thrown if value string can't be converted to a float.
	**/
	public void setValue(String value) throws NumberFormatException {
		if (value.equals("")) {
			defined = false;
			theValue = Float.NaN;
		} else {
			theValue = Float.valueOf(value).floatValue();
			if (theValue != Float.NaN)
				defined = true;
			else
				defined = false;
		}
	}


	/**
	* getLabel():	Method to return the string representation of the label
	*				of this parameter.
	*
	*	Written by:		Joseph A. Huwaldt		Date:	November 30, 1997
	*	Modified by:	Joseph A. Huwaldt		Date:	November 30, 1997
	*
	*	@param		No parameters
	*	@return		Returns the string representation of the parameter label.
	**/
	public String getLabel() {
		return labelStr;
	}

	/**
	* changeLabel():	Method to change the label that is associated with this parameter.
	*
	*	Written by:		Joseph A. Huwaldt		Date:	November 23, 1997
	*	Modified by:	Joseph A. Huwaldt		Date:	November 23, 1997
	*
	*	@param		label	The label to be attached to this object.
	*	@return		No return value
	**/
	public void changeLabel(String label) {
		labelStr = label;
	}


	/**
	* isDefined():	Returns true if parameter is defined, false otherwise.
	*
	*	Written by:		Joseph A. Huwaldt		Date:	November 29, 1997
	*	Modified by:	Joseph A. Huwaldt		Date:	November 29, 1997
	*
	*	@param		No parameters
	*	@return		Returns true if this parameter is defined.
	**/
	public boolean isDefined() {
		return defined;
	}

	/**
	* makeUndefined():	Method to make this parameter undefined.
	*
	*	Written by:		Joseph A. Huwaldt		Date:	November 23, 1997
	*	Modified by:	Joseph A. Huwaldt		Date:	November 23, 1997
	*
	*	@param		No parameters
	*	@return		No return value
	**/
	public void makeUndefined() {
		defined = false;
		theValue = Float.NaN;
		labelStr = null;
	}

	/**
	* toString():	Method to return the value of this parameter as a string.
	*
	*	Written by:		Joseph A. Huwaldt		Date:	November 23, 1997
	*	Modified by:	Joseph A. Huwaldt		Date:	November 23, 1997
	*
	*	@param		No parameters
	*	@return		Returns a string representation of the value of this parameter.
	**/
	public String toString() {
		return Float.toString(theValue);
	}
	

}	//	end Param class