/**
 * Time represented as attributes hours and minutes.
 * @author Dr. Jody Paul 
 * @version 1 March 2006
 */
public class Time {
    private int hours;
    private int minutes;

    /**
     * Constructor for objects of class Time that
     * sets time to zero (0:00).
     */
    public Time() {
        hours = 0;
        minutes = 0;
    }

    /**
     * Constructor for objects of class Time that
     * sets time to the number of minutes specified.
     * The time is normalized to the equivalent number
     * of hours and minutes such that minutes is in the
     * range 0..59 inclusive.
     * @param minutes the number of minutes
     */
    public Time(int minutes) {
        this.minutes = minutes;
        normalize();
    }

    /**
     * Constructor for objects of class Time that
     * sets time to the number of hours and minutes specified.
     * The time is normalized to the equivalent number
     * of hours and minutes such that minutes is in the
     * range 0..59 inclusive.
     * @param hours the number of hours
     * @param minutes the number of minutes
     */
    public Time(int hours, int minutes) {
        this.hours = hours;
        this.minutes = minutes;
        normalize();
    }
    
    /**
     * Normalizes the time so that minutes is < 60.
     */
    private void normalize() {
        if (minutes >= 60) {
            hours += minutes / 60;
            minutes %= 60;
        }
    }
    
    /**
     * Retrieve the hours.
     * @return the hours
     */
    public int getHours() { return hours; }
    
    /**
     * Retrieve the minutes.
     * @return the minutes
     */
    public int getMinutes() { return minutes; }
    
    /**
     * Create a new Time object whose value is the
     * current object's time incremented by the parameter.
     * A parameter of <CODE>null</CODE> is equivalent to <CODE>new Time()</CODE>. 
     * @param timeIncrement the amount to increment by
     * @return new time object
     */
    public Time increment(Time timeIncrement) {
        if (timeIncrement == null) {
           return new Time(hours, minutes);
        }
        return new Time(hours + timeIncrement.getHours(),
                        minutes + timeIncrement.getMinutes());
    }
    
    /**
     * Determine if two Time objects are equal.
     * Two Time objects are equal if and only if they have the same
     * number of hours and same number of minutes.
     * (Returns <CODE>false</CODE> if the specified Time is <CODE>null</CODE>.)
     * @param t the Time object to compare with this Time
     * @return <CODE>true</CODE> if the hours and minutes are the same; <CODE>false</CODE> otherwise
     */
    public boolean equals(Time t) {
        if (t == null) return false;
        return ((hours == t.getHours()) && (minutes == t.getMinutes()));
    }
 
}