Solar System Model

package solarsystem;

import java.util.Observable;

public class SolarSystemModel extends Observable {

    public static final int DAYS_PER_EARTH_REVOLUTION_AROUND_SUN = 365;
    public static final int HOURS_PER_EARTH_REVOLUTION_AROUND_AXIS = 24;

    // http://en.wikipedia.org/wiki/Orbit_of_the_Moon
    // "The orbit of the Moon around the Earth is completed in approximately 27.3 days"
    public static final float DAYS_PER_MOON_ORBIT_AROUND_EARTH = 27.3f;



    private int day;
    private int hour;

    public int getDay() {
        return day;
    }

    public void setDay(int day) {
        int oldDay = this.day;
        this.day = clampDay(day);
        if (oldDay != this.day) {
            setChanged();
            notifyObservers();
        }
    }

    public int getHour() {
        return hour;
    }

    public void setHour(int hour) {
        int oldHour = this.hour;
        this.hour = clampHour(hour);
        if (oldHour != this.hour) {
            setChanged();
            notifyObservers();
        }
    }



    private int clampDay(int day) {
        return day % DAYS_PER_EARTH_REVOLUTION_AROUND_SUN;
    }

    private int clampHour(int hour) {
        return hour % HOURS_PER_EARTH_REVOLUTION_AROUND_AXIS;
    }


}