calculator
Class CalculatorState

java.lang.Object
  calculator.CalculatorState

public class CalculatorState

extends java.lang.Object

This class provides the main functionality for a basic four-function calculator. Adapted from the earlier ButtonHandler

Copyright (c) 1999 Massachusetts Institute of Technology

Version:

$Id: CalculatorState.java,v 1.2 2003/03/28 17:25:06 gus Exp $

Author:

Todd C. Parnell, tparnell@ai.mit.edu, Emil Sit, sit@mit.edu, Lynn Andrea Stein, las@ai.mit.edu

See Also:

Calculator

Field Summary

protected int	operation
protected double	previousNumber
protected boolean	readyForNewNumber
protected boolean	seenDecimal

Constructor Summary

protected

CalculatorState(Calculator gui)

Method Summary

protected void	clearScreen()
protected double	doOperation(double currentNumber)
protected void	handleDecimal()
protected void	handleEquals()
protected void	handleNumKey(int num)
protected void	handleOperation(int op)
protected java.lang.String	readScreen()
protected void	resetCalc()
protected void	resetDecimal()
java.lang.String	toString()
protected void	writeScreen(double d)
protected void	writeScreen(int i)
protected void	writeScreen(java.lang.String s)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

seenDecimal

protected boolean seenDecimal

readyForNewNumber

protected boolean readyForNewNumber

previousNumber

protected double previousNumber

operation

protected int operation

Constructor Detail

CalculatorState

protected CalculatorState(Calculator gui)

Method Detail

toString

public java.lang.String toString()

handleNumKey

protected void handleNumKey(int num)

handleDecimal

protected void handleDecimal()

handleOperation

protected void handleOperation(int op)

handleEquals

protected void handleEquals()

doOperation

protected double doOperation(double currentNumber)

resetDecimal

protected void resetDecimal()

clearScreen

protected void clearScreen()

readScreen

protected java.lang.String readScreen()

writeScreen

protected void writeScreen(java.lang.String s)

writeScreen

protected void writeScreen(double d)

writeScreen

protected void writeScreen(int i)

resetCalc

protected void resetCalc()