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OTExample Observer/Flower

Simple base class for the Observer pattern

(note, that this class bears no pre-planning for being observed).

package flower_example;
 * @author Bruce Eckel (original Java example)
 * @author Miguel P. Monteiro (adaptation to OT/J)
 * Base class to play the Subject role
public class Flower {
    private boolean isOpen;
    public Flower() {
        isOpen = false;
    /** Opens its petals. */
    public void open() {
        isOpen = true;
    /** Closes its petals. */
    public void close() {
        isOpen = false;
    void print() {
        System.out.println("=> The flower is now "+(this.isOpen?"open":"closed")+".");

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