How do I get the current location when using slick 2D library?

Question

I'm developing a map kind of simple game using slick 2D library, and I want to get the current location of the user. When the user runs into a special location (ex: hole) to indicate that is dangerous. How can I achieve this? I'm a new comer to games.

Answer 1

Assuming that I understand what you are trying to do, that is, a 2D dungeon-like tiled game, here is what I would do:

The current location of the player can be stored in a Point class, and the entire player entity into a sprite, as is typically done in simple 2D game. I.e.:

class Sprite {
  Point position;
  Texture texture;
  ...
  public Point getPosition() {
     return this.position;
  }
}

So, to move your player all you do is listen for keyboard events and update the location:

class MyGame implements KeyListener
{
    Sprite player;
    ...
    public void keyPressed(int key, char c) {
        if (key == Input.KEY_W) {
            player.getPosition().X += 1;
        } else if (key == Input.KEY_S) {
            player.getPosition().X -= 1;
        } else if (key == Input.KEY_A) {
            player.getPoisition().Y -= 1;
        } else if (key == Input.KEY_D) {
            player.getPosition().Y += 1;
        }
    }
}

As for informing the player of dangerous locations, have a list of triggers that will fire whenever the player is inside an area. The triggers could be a rectangular location, a circle or anything. In general, you would have something like this:

class Level implements TriggerListener {
  List<LevelTriggers> levelTriggers;
  Sprite player;

  ...

  void initialize() {
     // Initialize all triggers (usually you read this part from a file)
     for (int i = 0; i < numberOfTriggers; i++) {
        LevelTrigger trigger = new LevelTrigger();
        trigger.addListener(this);
        levelTriggers.add(trigger);
     }
  }

  void update(...) {
     ...
     for (LevelTrigger trigger : levelTriggers) {
        if (trigger.isIn(player.getPosition())) {
           trigger.fire();
        }
     }
  }

  ...

  void triggered() {
     // Show your message
  }
}

abstract class LevelTrigger {
    List<TriggerListeners> triggerListeners;

    void addListener(TriggerListener triggerListener)
    {
       triggerLIsteners.add(triggerListeners);
    }

    void fire()
    {
       for (TriggerListener listener : triggerListeners)
       {
          listener.triggered();
       }
    }

    abstract bool isIn(Point position);
}

interface TriggerListener
{
    triggered();
}

EDIT: Totally forgot to mention the "current location" part.
EDIT2: OK, I GOT to stop writing C# code in Java questions :/