I'm working on a game project. I created a GUI class and I want to create an instance of it for each player of the game. So each player will have one screen of the game.
Some information will be displayed on a specific player screen and some will be common. To display common informations, I created a static JLabel in which I put an icon. But I have a problem, the icon only appears on one of the screens.
Why does this happen?
Short answer: you can't. A basic rule of the Swing library is that a component will only be displayed in one and only one container, usually the last container that the component was added to.
The longer answer: you don't want to. You want to structure your program in such a way that the program's model, its logical underpinnings, is well separated from its view, the GUI itself. So what you want to do is have each GUI element share the same model, and use this information to create its own unique view. This has advantages as well, since if a player wants to display elements in a different perspective or point of view, they can do this without affecting what the other players see.
Side note: note that a single ImageIcon can be shared and viewed in multiple separate locations of your GUI since it is not a Swing component, but the JLabel can't be viewed in multiple locations.
Side note 2: Be sure to read: The Use of Multiple JFrames: Good or Bad Practice?, as this contains information pertinent to your program structure.
Side note 3, regarding:
To display common informations, I created a static JLabel...
I would avoid using static fields if at all possible. While this is fine to do in small simple toy programs, it does not scale well since the more static fields you use, the greater the risk of increasing the coupling of your code, and thus increasing its (cyclomatic) complexity, and thus increasing its risk of having hard to cure bugs. Follow good OOP practices by hiding your information, increasing your class cohesion and reducing code coupling, and you'll be a happy coder with cleaner, easier to debug and enhance programs.
