/**
 * Chapter 3, exercise 2, page 123
 *
 * Write a declaration for the BallpointPen class
 * as desribed in section 3.2.  Leave the body
 * of the methods empty.
 *
 ***/
public class BallpointPen {

    // variables (data) 
    private boolean pointIsExposed;
    private double inkRemaining;

    BallpointPen(){
    }

    // toggle value of pointIsExposed.
    public void pressButton() {
	pointIsExposed = ! pointIsExposed;
    }

    // reduce inkRemaining
    public void write(int secSpentWriting){
	inkRemaining = inkRemaining - secSpentWriting;
    }

    // reset inkRemaining to original value
    public void replaceCartridge(){
	inkRemaining = 1000.0;
    }
    
    // return value of inkRemaining
    public double checkInkRemaining(){
	return inkRemaining;
    }
    
}

// =================================================

/**
 * Chapter 5, exercise 5, page 123
 *
 * Write a declaration for the BallpointPen class
 * as desribed in section 3.2.  Leave the body
 * of the methods empty.
 *
 ***/

/*
    (a) press the button
    (b) write for 200 sec
    (c) replace cartridge
    (d) 
*/

BallpointPen jimsPen = new BallpointPen();
jimsPen.pressButton();
jimsPen.write(200);       // write for 200 seconds.
jimsPen.replaceCartridge();
double inkLeft = jimsPen.checkInkRemaining();