becker.xtras.gasPump
Class SampleMeter

java.lang.Object
  becker.xtras.gasPump.SampleMeter

All Implemented Interfaces:

IMeter

public final class SampleMeter
extends Object
implements IMeter

A sample class implementing the IMeter interface. It measures the volume of fuel sold and calculates the amount owed by the customer, given the current fuel cost.

Please see the package description for a more in-depth discussion of using this class.

Author:

Byron Weber Becker

Constructor Summary

SampleMeter(double unitCost, int octaneRating, String theLabel)
Construct a new fuel meter.

Method Summary

void	addView(IView aView) Add a view (graphical user interface) to the meter.
double	calcTotalCost() Calculate the total cost of fuel sold to this customer.
String	getLabel() Get the label for this meter's fuel.
int	getOctane() Get the octane rating of the fuel.
double	getUnitCost() Get the cost per unit of fuel.
double	getVolumeSold() Get the volume of fuel sold to this customer.
static void	main(String[] args) Used to test the class.
void	pump(double howMuch) Pump some fuel into a tank.
void	reset() Reset the meter for a new customer.

Methods inherited from class java.lang.Object

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

Constructor Detail

SampleMeter

public SampleMeter(double unitCost,
                   int octaneRating,
                   String theLabel)

Construct a new fuel meter.

Parameters:

unitCost - The cost per unit volume of fuel. For example, $2.85/gallon or $1.05/litre.

octaneRating - An integer related to the "performance" of the fuel; usually between 87 and 93.

theLabel - A label for the fuel such as "Gold" or "Ultra".

Method Detail

reset

public void reset()

Description copied from interface: IMeter

Reset the meter for a new customer.

Specified by:

reset in interface IMeter

pump

public void pump(double howMuch)

Description copied from interface: IMeter

Pump some fuel into a tank. This method is called repeatedly while the "handle" on the pump is pressed.

Specified by:

pump in interface IMeter

Parameters:

howMuch - How much fuel was pumped since the last time this method was called.

getUnitCost

public double getUnitCost()

Description copied from interface: IMeter

Get the cost per unit of fuel.

Specified by:

getUnitCost in interface IMeter

Returns:

cost per unit of fuel

getVolumeSold

public double getVolumeSold()

Description copied from interface: IMeter

Get the volume of fuel sold to this customer.

Specified by:

getVolumeSold in interface IMeter

Returns:

volume of fuel sold

getOctane

public int getOctane()

Description copied from interface: IMeter

Get the octane rating of the fuel.

Specified by:

getOctane in interface IMeter

Returns:

octane rating (typically between 87 and 93)

getLabel

public String getLabel()

Description copied from interface: IMeter

Get the label for this meter's fuel. For example, "Gold" or "Ultra".

Specified by:

getLabel in interface IMeter

Returns:

this meter's fuel label

calcTotalCost

public double calcTotalCost()

Description copied from interface: IMeter

Calculate the total cost of fuel sold to this customer.

Specified by:

calcTotalCost in interface IMeter

Returns:

price/unit * number of units sold

addView

public void addView(IView aView)

Description copied from interface: IMeter

Add a view (graphical user interface) to the meter. The view's updateView method must be called each time the meter's state changes.

Specified by:

addView in interface IMeter

main

public static void main(String[] args)

Used to test the class.