Java ADT

README.md

Java ADT

This pattern allows one to use "ADT" in Java. You publish a TileEvent, and you use instanceof to know which kind of event it is.

TileEvent tileEvent = (TileEvent) object;
if (tileEvent instanceof TileEvent.Set) {
    TileEvent.Set event = (TileEvent.Set) tileEvent;
    System.out.printf("Set Event at %s on level %s with sprite %s",
            event.getPosition(), event.getLevel(), event.getSprite());
}

TileEvent.java

import java.awt.*;
import [Sprite, SpriteLevel...];

public abstract class TileEvent {
  private Point position;

  private TileEvent(Point position) {
    this.position = position;
  }

  public Point getPoint() {
    return position;
  }

  public class Set extends TileEvent {
    private Sprite sprite;
    private SpriteLevel level;

    public Set(Point position, Sprite sprite, SpriteLevel level) {
      super(position);
      this.sprite = sprite;
      this.level = level;
    }

    public Sprite getSprite() {
      return sprite;
    }

    public SpriteLevel getLevel() {
      return level;
    }
  }

  public class Clear extends TileEvent {
    private SpriteLevel level;

    public Clear(SpriteLevel level) {
      super(position);
      this.level = level;
    }
  }
}