Drawing a Label Containing an Icon Showing a Circl

Question

So I am trying to draw a label which contains an icon showing a circle. The circle will initially be filled red, and then depending on which of the 3 buttons I press, it will either change to green, blue, or red using repaint.

Here is what I have so far:

public class ColorChanger implements Icon {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        JFrame myFrame = new JFrame();
        JButton redButton = new JButton("Red");
        JButton greenButton = new JButton("Green");
        JButton blueButton = new JButton("Blue");
        Graphics g;

        ColorChanger myCircle = new ColorChanger();
        final JLabel myLabel = new JLabel(myCircle);

    //  myCircle.paintIcon(myFrame, g, 50, 50);

        final int FRAME_WIDTH = 300;
        final int FRAME_HEIGHT = 200; 

        myFrame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
        myFrame.setLayout(new FlowLayout());

        myFrame.add(redButton);
        myFrame.add(greenButton);
        myFrame.add(blueButton);
        myFrame.add(myLabel);

        myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
        myFrame.pack();
        myFrame.setVisible(true); 
    }

    @Override
    public int getIconWidth() {
        // TODO Auto-generated method stub
        return 10;
    }

    @Override
    public int getIconHeight() {
        // TODO Auto-generated method stub
        return 10;
    }

    @Override
    public void paintIcon(Component c, Graphics g, int x, int y) {
        // TODO Auto-generated method stub
        Graphics2D g2 = (Graphics2D) g;
        Ellipse2D.Double circle = new Ellipse2D.Double(50, 50, 10, 10);
        g2.setColor(Color.RED);
        g2.fill(circle);
    }    
}

My issue is, I have no idea what to pass for the Graphics g in paintIcon. Is there a different way to do this? I appreciate any help with this.

Answer 1

Ellipse2D.Double circle = new Ellipse2D.Double(50, 50, 10, 10);

The size of the icon is (10, 10). 50, is outside the bounds of the Icon. Painting is done relative to the icon so the ellipse should be:

Ellipse2D.Double circle = new Ellipse2D.Double(0, 0, 10, 10);

it will either change to green, blue, or red using repaint.

Your ColorChanger class will need a setColor(Color color) method so that you can dynamically change the color to be painted. The paintIcon() method should then use this color.