/**
 * This version of ClockDisplay implements everything in the 
 * ClockDisplay class, rather than building off of NumberDisplay.
 * 
 * @author Michael Kölling, David J. Barnes, and Brad Richards
 * @version 2.0
 */
public class ClockDisplay_merged
{
    private int hoursValue;
    private int minutesValue;
    private String displayString;    // simulates the actual display
    
    public final int MIN_LIMIT = 60;
    public final int HOUR_LIMIT = 24;
    /**
     * Constructor for ClockDisplay objects. This constructor 
     * creates a new clock set at 00:00.
     */
    public ClockDisplay_merged()
    {
        hoursValue = 0;
        minutesValue = 0;
        updateDisplay();
    }

    /**
     * Constructor for ClockDisplay objects. This constructor
     * creates a new clock set at the time specified by the 
     * parameters.
     * @param hour The hour to use in setting time
     * @param minute The minute value to use in setting time
     */
    public ClockDisplay_merged(int hour, int minute)
    {
        setTime(hour, minute);
    }

    /**
     * This method should get called once every minute - it makes
     * the clock display go one minute forward.
     */
    public void timeTick()
    {
        minutesValue = minutesValue + 1;
        if (minutesValue > MIN_LIMIT) {
            minutesValue = 0;
            hoursValue = hoursValue + 1;
            if (hoursValue > HOUR_LIMIT) {
                hoursValue = 0;
            }
        }

        updateDisplay();
    }

    /**
     * Set the time of the display to the specified hour and
     * minute.
     * @param hour The hour to use in setting time
     * @param minute The minute value to use in setting time
     */
    public void setTime(int hour, int minute)
    {
        hoursValue = hour;
        minutesValue = minute;
        updateDisplay();
    }

    /**
     * Return the current time of this display in the format HH:MM.
     * @return Returns the time as a string.
     */
    public String getTime()
    {
        return displayString;
    }
    
    /**
     * Update the internal string that represents the display.
     */
    private void updateDisplay()
    {
        String hoursString;
        String minutesString;
        if (hoursValue < 10) {
            hoursString = "0" + hoursValue;
        }
        else {
            hoursString = "" + hoursValue;
        }
        if (minutesValue < 10) {
            minutesString = "0" + minutesValue;
        }
        else {
            minutesString = "" + minutesValue;
        }
        
        displayString = hoursString + ":" + minutesString;
    }
}