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Thread: extends question

  1. #1
    Join Date
    Mar 2011
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    Default extends question

    hi, Silly question however. I'm testing a couple of problems, For example disable all components in the swing class that extends JApplet.

    For example this code:

    public class gameLobby extends JApplet
    public class gameChat extends gameLobby
       // How would you do the following
    note: "this" is refering to the extending class (gameLobby)

    How do you get that Applet from another class and set JApplet.enabled(false)
    not sure if it will set the components disabled, im guessing it will because how can the components be enabled if the parent isnt..

    Thanks guys

  2. #2
    Super Moderator Norm's Avatar
    Join Date
    May 2010
    Eastern Florida
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    Default Re: extends question

    disable all components
    What components are you referring to? Are you asking about components that have been added to a container?
    What does the API doc say for the various methods you are talking about?

    Write a small test program and try some of the techniques to see what happens.
    If you don't understand my answer, don't ignore it, ask a question.

  3. #3
    Join Date
    Jun 2011
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    Default Re: extends question

    First of all, I realize this is nitpicky, but it kind of matters, I highly suggest you follow Java naming conventions. Your classes should start with a capital letter (i.e. GameChat and GameLobby).

    'This' does not refer to the superclass. 'This' refers to the current instance of that object, so in your case the current instance of 'gameChat'.

    Calling getParent() has nothing to do with the object oriented structure of your program. Don't confuse Swing's layout system with your Object hierarchy!

    getParent() returns the parent container of the component. It's probably null for a JApplet.

    You get the Applet from another class simply by passing it in a method or constructor. You can then call any of its methods, including setEnabled(boolean).

    Example 1
    public class SomethingElse {
        public SomethingElse(gameLobby lobby) {

    Example 2
    private static gameLobby inst;
    public gameLobby() {
        inst = this;
    public static gameLobby getInstance() {
        return inst;

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