Setting up dynamic actions

Question

Hullo there,
I'm still on my way with my Monopoly game.
Now, I have a center panel displaying the squares 'properties' when a player lands on it. For example, when he lands on a Station, the center panel has a list with the price, the owner (if owned), etc. This is done via a SquareListener.
So far, so good. BUT, I'd like now to give the player options in a popup menu.
For example, if the square is owned by himself, he can't buy it, but can sell it or built it. On the other hand, he may buy each square which isn't already oned by somebody...
This is where I'm stuck. My square listener isn't enough here. I'll have a lot of testing and checking to do for each square. So I thought there might be another solution for this.Maybe a list of actions. But what of type would be these ? Moreover, the actions cannot belong to the square, since they will be different for each player (see above).
What am I to do there ?
Sorry if it's a bit confuse, I'm confused and quite lost here, to say the truth.

Answer 1

1) Is it the correct way to do it or should I create a
separate Actions class ?Why are you re-creating the actions all the time?
I would write it as:
public class Square {
    Action buy;
    Action build;
    Action[] allActions;
    //Add some more attributes
    public Square()  {
        buyAction = new BuyAction();
        build = new BuildAction();
        allActions = new Action[] { buy, build };
    public Action[] getAction(Player player) {  //The method could return a JMenu
        for (int i=0; i<allActions.length; i++) {
            allActions.setEnabled(true);
if (player.equals(owner)) {
buy.setEnabled(false);
return allActions;
class BuyAction extends AbstractAction {
//Add some code here
//Add code for the other inner classes
You could either write the actions as innerclasses, or as separate classes, and write a callback interface. Depends on your situation.
2) I read somewhere some time ago (don't remember
where nor when) that custom actions where memory
consuming and one should prefer actionListeners. Is
this true ? You don't have to bother about that in your case (just try to change your implementation so that you aren't re-creating all actions all the time. Actions is what you should normally use, since an action can be re-used. I.e. you can add/set the same action to a button and menu item etc. And when you disable the action, all buttons and menu items that has it will be disabled.
/Kaj