You need a reference to the other actor (i.e. some way to identify it). For instance, if you have a variable called 'actor' containing the reference to the actor whose position you need, you can use "actor.getX()" and "actor.getY()" for example to get its position. (You haven't given much information about what you're really trying to do, so that's about as much help as anyone can give...)

i'm also trying the same thing , the only thing i get in return is a nullpointerexeption . public class Actor1 extends Actor { Actor2 actor2; public void getPosactor2() { int x = actor2.getX(); int y = actor2.getY(); System.out.println("x+y"); } }

That's because you never initialize the actor2 object. Do this in your constructor, just add this code: But, what is actor2? What does it represent?

Oops, this is the right code: Of course, (something) is not valid code.

This line: Actor2 actor2; Declares a variable - which can hold a reference to an object, but initially does not. It doesn't create an object. You need to assign something to the variable. As to what - well, I don't know, because you still haven't explained what object you want to get the location of...

So... I have a character which walks on a map. If he is at the maps end, i would like that buttons will apear around him. Then you can click on these buttons for choosing in wich direction the character is going to walk. My teacher told me that these buttons should be actors. And i have really no idea how i can assign their position in dependence to the character. Actually i only want to understand how to create a variable with the actor as contant. Or i don´t have to do that?...

its fairly easy ;) put this piece of code into your actor ;) of course you have to adjust it to your world ;) this is just for a standard 600x400 world, but it should be no problem for you to change this ;)

@niklaskar, that would work fine, if the buttons did not need to know which way to point. @schepieli, add an integer parameter to the Button class object constructor to recieve a value, from 0 to 3, indicating how much rotation to apply (* 90). The Button constructor should look something like this: Then, in the code provided by niklaskar, put the appropriate values in the constructor calls (i.e. 'new Button(3) for 'up'; or 'new Button(2)' for 'left'). Or, instead of his code, you could put in the act method of the actor that walks: and add the following method: BTW, the 'atWorldEdge' method or the check you use in place of it should compensate for the size of the image of the actor (i.e. 'if (getX() <= getImage().getWidth() / 2)', or 'if (getX() >= getWorld().getWidth() - getImage().getWidth() / 2 - 1)'). By not compensating for it, your button objects will be half cut off by the edges of the screen.

I'm understanding it needs to be referenced, but what would it look like if I wanted to put my "gun" actor as actor2? How do I understand I'm talking about another actor? I feel like I should know this and I'm drawing blank..

See this tutorial, which explains a common way to do it. You can also add an actor parameter to another actor's constructor, or, you can have one actor create another. So for instance if your player actor always has a gun, and the gun is a separate actor, you could create the gun in the player's constructor (or in its 'addedToWorld' method).

I am making a Tron-style game, and I am finding it difficult to create trail instances at the location of the character. I am relatively new to Greenfoot so please keep any explanations simple. The trail instance is a subclass of the character. The character has no code other than basic arrow key control scripts. I have spent an hour or so trying to work out how to make this work using google, but I cannot seem to find a relatively simple way of making this work. Is there no way to make public variables accessible by other classes? Thanks, barnstorm3r

@barnstorm3r, please do not rekindle discussion that are not recent. Also, it would be best if instead of jumping into the middle of a discussion that you start your own that will deal with your issue. Mixing issues in one discussion could get confusing for someone who later reviews it. I encourage you to start a new discussion on this matter.