Static, Exercise 01, slide 24

Static, Exercise 01, slide 24

class Tester
*****************************************************************************
public class Tester {

    public static void main(String[] args) {
        // create two clocks
        Clock c1 = new Clock(23, 59);
        Clock c2 = new Clock(c1);
        c2.setHours(11, Clock.AmPm.AM);

        // display clocks on format 24 hours
        System.out.println("Dispaly in 24 hours format:");
        System.out.println("c1 = " + c1);
        System.out.println("c2 = " + c2);

        // change display format to 12 hours
        Clock.displayFormat = TimeFormat.TF12;

        // display clocks on format 12 hours
        System.out.println("Dispaly in 12 hours format:");
        System.out.println("c1 = " + c1);
        System.out.println("c2 = " + c2);

        // clocks tick
        System.out.println("after one tick:");
        c1.tick();
        c2.tick();

        System.out.println("c1 = " + c1);
        System.out.println("c2 = " + c2);

        // clocks tick
        System.out.println("after one tick:");
        c1.tick();
        c2.tick();

        System.out.println("c1 = " + c1);
        System.out.println("c2 = " + c2);

        // change display format to 24 hours
        Clock.displayFormat = TimeFormat.TF24;

        // display clocks on format 24 hours
        System.out.println("Dispaly in 24 hours format:");
        System.out.println("c1 = " + c1);
        System.out.println("c2 = " + c2);
    }

}


// class Clock
*****************************************************************************
public class Clock {
    // class attributes, shared to all class instances
    // should be initialized even before calling constructor
    private static final int DAY_HOURS = 24;
    private static final int HOUR_MINUTES = 60; // maximum minutes in one hour
    public static TimeFormat displayFormat = TimeFormat.TF24; // time format
                                                                // for

    public static enum AmPm {
        AM, PM
    };

    // instance attributes, always save data in format 24 hours
    private int hours; // clock hours, always saved data in 24 format
    private int minutes; // clock minutes

    // private AmPm meridiem; // AM or PM : indicated by hours

    // constructor, arguments in 12 hours format
    public Clock(int hours, int minutes, AmPm meridiem) {
        this(toFormat24(hours, meridiem), minutes);
    }

    // constructor, arguments in 24 hours format
    public Clock(int hours, int minutes) {
        if (!this.setHours(hours)) {
            this.hours = TimeFormat.TF24.minHour;
        }
        this.setMinutes(minutes);
    }

    // copy constructor
    public Clock(Clock otherClock) {
        this.hours = otherClock.hours;
        this.minutes = otherClock.minutes;
    }

    // getter and setter for minutes
    public int getMinutes() {
        return this.minutes;
    }

    private boolean setMinutes(int minutes) {
        if (minutes < 0 || minutes >= HOUR_MINUTES)
            return false;

        this.minutes = minutes;
        return true;
    }

    // getter and setter for hours
    public int getHours() {
        return this.hours;
    }

    public boolean setHours(int hours) {
        if (hours < TimeFormat.TF24.minHour || hours > TimeFormat.TF24.maxHour)
            return false;

        this.hours = hours;
        return true;
    }

    public boolean setHours(int hours, AmPm meridiem) {
        return setHours(toFormat24(hours, meridiem));
    }

    private static int toFormat24(int hour, AmPm meridiem) {
        return meridiem == AmPm.PM ? (hour + 12) % DAY_HOURS : hour;
    }

    private static int toFormat12(int hour) {
        if (hour == 0)
            return displayFormat.maxHour;
        if (hour > displayFormat.maxHour)
            return hour - displayFormat.maxHour;
        return hour;
    }

    private String getMeridiem() {
        if (this.hours == 0)
            return minutes == 0 ? "midnight" : "AM";
        if (hours < displayFormat.maxHour)
            return "AM";
        if (hours == displayFormat.maxHour)
            return minutes == 0 ? "noon" : "PM";

        return "PM";
    }

    public void tick() {
        this.minutes += 1;
        if (minutes == HOUR_MINUTES) {
            minutes = 0;

            hours += 1;
            if (hours > TimeFormat.TF24.maxHour)
                hours = TimeFormat.TF24.minHour;
        }

    }

    @Override
    public String toString() {
        if (displayFormat == TimeFormat.TF24)
            return String.format("%02d:%02d", this.hours, this.minutes);
        else {
            return String.format("%02d:%02d (%s)", toFormat12(this.hours),
                    this.minutes, getMeridiem());
        }
    }
}

enum TimeFormat
**************************************************************************************
public enum TimeFormat {
    TF12(1, 12), TF24(0, 23);

    public final int minHour;
    public final int maxHour;

    private TimeFormat(int minHour, int maxHour) {
        this.minHour = minHour;
        this.maxHour = maxHour;
    }

}