如何使此 JPanel 中的像素动态变化？

Question

I have designed a program that outputs 1x1 rectangles (That I'll from now on call Pixels) with a color that is randomized between a random variable between Red, Green, and Blue. Now I want to take it one step further. First off, here's the source:

public class GUI extends JPanel {
private final static int MAX_X = 1920;
private final static int MAX_Y = 1080;

public void paintComponent(Graphics g) {
    super.paintComponent(g);

    for (int x = 0; x < MAX_X; x++) {
        for (int y = 0; y < MAX_Y; y++) {
  
            Color randomColor = Color.BLACK; //Black because it wouldn't work uninitialized.
            
            //Slightly inefficient? 
            int number; Random rColor = new Random();
            number = rColor.nextInt(3);
            
             if(number == 0){randomColor = Color.RED;}
             else if(number ==1){randomColor = Color.GREEN;}
             else if(number == 2){randomColor = Color.BLUE;}
            
            
            g.setColor(randomColor); //Red, Blue, or Green. Depends on if number is 0, 1 or 2.
            g.drawRect(x, y, 1, 1); 
        }
           
    
    }
    
}

}

It works, and it works like how I expect. Here's the next challenge: How can I make them continuously change? What I want is, if a neighboring pixel is blue than have the pixel be green and then any green to red and red to blue. I'm not sure with how it currently is setup that it'll be possible.

Side note: I have a feeling there's a way to minimize those couple lines of code I labeled in a comment as "Slightly Inefficient" into something cleaner like inside parameters. I've been looking up documentation for a while but I can't find a more functional use for Random.

Entire Code

Answer 1

you can use a timer to keep changing. for example: modify your gui class with following code and see . this timer run each half second and repaint jpanel.you can change 500 to desired milisecond.it will look like this.

you don't need to create a new random number each time . randomnumber.nextInt is enough and you make number as instance

public class GUI extends JPanel {

    private final static int MAX_X = 200;
    private final static int MAX_Y = 150;
    private final Color RED = Color.RED, GREEN = Color.GREEN, BLUE = Color.BLUE;
    private final Random rColor = new Random();
    private int number;
    private Color randomColor;

    public GUI() {
        new Timer(1, new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                repaint();
            }
        }).start();
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);

        for (int x = 0; x < MAX_X; x++) {
            for (int y = 0; y < MAX_Y; y++) {

                number = rColor.nextInt(3);

                if (number == 0) { randomColor = RED;
                } else if (number == 1) { randomColor = GREEN;
                } else if (number == 2) {randomColor = BLUE;
                }

                g.setColor(randomColor);
                g.drawRect(x, y, 1, 1);
            }

        }

    }
}