NumberDisplay.java

package ObjectInteraction;

public class NumberDisplay {

    private int limit;
    private int value;

    /**
     * Constructor for objects of class NumberDisplay
     */
    public NumberDisplay(int rollOverLimit) {
        limit = rollOverLimit;
        value = 0;
    }

    /**
     * Return the current value.
     */
    public int getValue() {
        return value;
    }

    /**
     * Set the value of the display to the new specified
     * value. If the new value is less than zero or over the
     * limit, do nothing.
     */
    public void setValue(int replacementValue) {
        if((replacementValue >= 0) && (replacementValue < limit)) {
            value = replacementValue;
        }
    }

    /**
     * Return the display value (that is, the current value
     * as a two-digit String. If the value is less than ten,
     * it will be padded with a leading zero).
     */
    public String getDisplayValue() {
        if(value < 10) {
            return "0" + value;
        } else {
            return "" + value;
        }
    }

    /**
     * Increment the display value by one, rolling over to zero if
     * the limit is reached.
     */

    public void increment() {
        value = (value + 1) % limit;
    }
}