How to draw a circle on button press

Question

I am trying to draw a circle when a button is pressed.

public Buttons(Panel panel){
    addStud = new JButton("+ Student");
    addStud.setToolTipText("Add a student");
    addStud.addActionListener(new AbstractAction() {
        @Override
        public void actionPerformed(ActionEvent e) {
            //draw circle here
        }
    });

This is my button in Button.java

public void draw(Graphics g){
    g.setColor(Color.BLUE);
    g.fillOval(200, 200, 400, 50);
}

This is what I am trying to call in Panel.java

I have a public void paintComponent(Graphics g) but I don't want the circle to be drawn immediately. I have tried initializing Panel() and calling it with no success. What can I do here?

Answer 1

class MyPanel extends JPanel {
       Boolean drawBlue = false;

    public void drawBlueCircle( Boolean draw ) {
       drawBlue = draw;
       repaint();
    }

    protected void paintComponent( Graphics g ) {
       if ( drawBlue ) {
          g.setColor(Color.BLUE);
          g.fillOval(200, 200, 400, 50);
       }
     }
}

Then in your button's actionPerformed method call

 myPanel.drawBlueCircle(true);

where myPanel is the instance of MyPanel that you created.