calculator
Interface Calculator

All Known Implementing Classes:

CalculatorGUI

public interface Calculator

This is the interface for a basic four-function calculator, as seen from the perspective of its logic. This interface defines an enumerated type, buttonIDs (including 0...9, which represent themselves), an array of ButtonLabels suitable for displaying on the GUI, and the three access functions by which the logic can manipulate the Calculator: getButton, getText, and setText.

See Also:

CalculatorGUI

Field Summary

static java.lang.String[]	ButtonLabels An array for the button's labels to deal with dispatch cleanly.
static int	CLEAR Calculator clear button.
static int	DOT Calculator decimal point.
static int	EQUALS Calculator = button.
static int	LAST One more than the biggest button index.
static int	NO_OP No operation in progress.
static int	OP_ADD Calculator addition.
static int	OP_DIV Calculator division.
static int	OP_MUL Calculator multiplication.
static int	OP_SUB Calculator subtraction.

Method Summary

int	getButton() Get the next Button pressed.
java.lang.String	getText() Get the text currently displayed on the Calculator.
void	setText(java.lang.String newText) Set the text currently displayed on the Calculator.

Field Detail

NO_OP

public static final int NO_OP

No operation in progress.

See Also:

Constant Field Values

OP_DIV

public static final int OP_DIV

Calculator division.

See Also:

Constant Field Values

OP_MUL

public static final int OP_MUL

Calculator multiplication.

See Also:

Constant Field Values

OP_ADD

public static final int OP_ADD

Calculator addition.

See Also:

Constant Field Values

OP_SUB

public static final int OP_SUB

Calculator subtraction.

See Also:

Constant Field Values

DOT

public static final int DOT

Calculator decimal point.

See Also:

Constant Field Values

EQUALS

public static final int EQUALS

Calculator = button.

See Also:

Constant Field Values

CLEAR

public static final int CLEAR

Calculator clear button.

See Also:

Constant Field Values

LAST

public static final int LAST

One more than the biggest button index.

See Also:

Constant Field Values

ButtonLabels

public static final java.lang.String[] ButtonLabels

An array for the button's labels to deal with dispatch cleanly. You can use this to get the name of the button (i.e., a String).

Method Detail

getButton

public int getButton()

Get the next Button pressed. The return value will be an int between 0 and 9 (if the button was a number) or one of the Calculator constants.

Returns:

the next button to be handled.

getText

public java.lang.String getText()

Get the text currently displayed on the Calculator.

Returns:

the text as a String.

setText

public void setText(java.lang.String newText)

Set the text currently displayed on the Calculator.

Parameters:

newText - the text to be displayed.