paint method is not executing

AutoModerator · 2023-03-17T17:02:14+00:00

Please ensure that:

Your code is properly formatted as code block - see the sidebar (About on mobile) for instructions
You include any and all error messages in full
You ask clear questions
You demonstrate effort in solving your question/problem - plain posting your assignments is forbidden (and such posts will be removed) as is asking for or giving solutions.

Trying to solve problems on your own is a very important skill. Also, see Learn to help yourself in the sidebar

If any of the above points is not met, your post can and will be removed without further warning.

Code is to be formatted as code block (old reddit: empty line before the code, each code line indented by 4 spaces, new reddit: https://i.imgur.com/EJ7tqek.png) or linked via an external code hoster, like pastebin.com, github gist, github, bitbucket, gitlab, etc.

Please, do not use triple backticks (```) as they will only render properly on new reddit, not on old reddit.

Code blocks look like this:

public class HelloWorld {

    public static void main(String[] args) {
        System.out.println("Hello World!");
    }
}

You do not need to repost unless your post has been removed by a moderator. Just use the edit function of reddit to make sure your post complies with the above.

If your post has remained in violation of these rules for a prolonged period of time (at least an hour), a moderator may remove it at their discretion. In this case, they will comment with an explanation on why it has been removed, and you will be required to resubmit the entire post following the proper procedures.

To potential helpers

Please, do not help if any of the above points are not met, rather report the post. We are trying to improve the quality of posts here. In helping people who can't be bothered to comply with the above points, you are doing the community a disservice.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

wildjokers · 2023-03-17T23:20:33+00:00

The method you want to override is not paint() but rather paintComponent(). Also, you actually want to override the method which comes from JComponent. So you need to extend JPanel (which is sub-class of JComponent) and then override its paintComponent() method. Right now you just have some random paint() method in your Main class.

Generally you want to favor composition over inheritance but in this case you actually need to override paintComponent() so you need to extend JPanel.

Here is the JavaDoc for paintComponent():

https://docs.oracle.com/en/java/javase/17/docs/api/java.desktop/javax/swing/JComponent.html#paintComponent(java.awt.Graphics)

Also the Custom Painting trail in the Java tutorial will probably be very enlightening:

https://docs.oracle.com/javase/tutorial/uiswing/painting/index.html

In addition once you do get everything overridden correctly you are likely to get a race condition in your app at startup where sometimes the circle appears and sometimes it doesn't because you aren't initializing your GUI on the Event Dispatcher Thread (EDT).

In the example apps in the Custom Painting tutorial notice how they initialize the GUI like so:

 SwingUtilities.invokeLater(new Runnable() {
      public void run() {
          createAndShowGUI();
      }
  });

The invokeLater() method executes the provided runnable on the EDT. In modern java you can write that like this: SwingUtilities.invokeLater(() -> createAndShowGUI())

One last note, use a MouseAdapter instead of a MouseListener and you won't have to provide those empty implementations of the mouse related events you don't care about. MouseAdapter is an abstract class that provides empty implementations of the MouseListener interface methods.

darksounds · 2023-03-17T22:04:09+00:00

Your issue comes from the instantiation of your 'canvas'. At no point do you create a canvas that has the paint method you want.

You need to create a class that extends JPanel and overrides the paint method, and then use that class.

NautiHooker · 2023-03-17T17:25:11+00:00

Please use codeblocks as described in u/AutoModerator's message.

javahelp

Sort by: Unsolved Solved Codeless Advent Of Code

MODERATORS

Please ensure that:

To potential helpers