Question

I do not know where to add ActionListeners/ItemListener and need help:
This is the desired output:

• If you selected a shape in checkboxes, it will draw a type of shape you selected
• and if you selected radiobutton, it will fill color(maybe a blue color)

here’s the code:

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.ButtonGroup;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.border.Border;

public class ARadioCombo {

   public static void main(String args[]) {

      JFrame frame = new JFrame("Radio/Combo Example");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      JPanel panel = new JPanel(new GridLayout(0, 1));
      Border border = BorderFactory.createTitledBorder("Fill/Unfill");

      panel.setBorder(border);
      ButtonGroup group = new ButtonGroup();
      JRadioButton aRadioButton = new JRadioButton("Fill Color");
      panel.add(aRadioButton);
      group.add(aRadioButton);

      aRadioButton = new JRadioButton("Remove Fill");
      panel.add(aRadioButton);
      group.add(aRadioButton);

      Container contentPane = frame.getContentPane();
      contentPane.add(panel, BorderLayout.WEST);
      panel = new JPanel(new GridLayout(0, 1));

      border = BorderFactory.createTitledBorder("Select Shape");
      panel.setBorder(border);

      JCheckBox aCheckBox = new JCheckBox("Oval");
      panel.add(aCheckBox);

      aCheckBox = new JCheckBox("Square", true);
      panel.add(aCheckBox);

      aCheckBox = new JCheckBox("Rectangle");
      panel.add(aCheckBox);

      aCheckBox = new JCheckBox("Circle");
      panel.add(aCheckBox);

      contentPane.add(panel, BorderLayout.EAST);
      frame.setSize(300, 200);
      frame.setVisible(true);
   }
}

Answer 1

You should add your ActionListeners to any buttons that the user interacts with, here your JRadioButtons. So where you have this:

  JRadioButton aRadioButton = new JRadioButton("Fill Color");
  panel.add(aRadioButton);
  group.add(aRadioButton);

  aRadioButton = new JRadioButton("Remove Fill");
  panel.add(aRadioButton);
  group.add(aRadioButton);

You could have something like this:

  ActionListener myActionListener = new ActionListener() {
     public void actionPerformed(ActionEvent e) {
        // TODO: put in code I want to have happen on button selection 
        // One ActionListener can likely be used for all buttons in this 
        // small program.
        // as noted below, it could be as simple as one line saying:
        // repaint();
     }
  };
  JRadioButton aRadioButton = new JRadioButton("Fill Color");
  panel.add(aRadioButton);
  group.add(aRadioButton);
  aRadioButton.addActionListener(myActionListener);

  aRadioButton = new JRadioButton("Remove Fill");
  panel.add(aRadioButton);
  group.add(aRadioButton);
  aRadioButton.addActionListener(myActionListener); // add to each radiobutton object

Also, shouldn’t your JCheckBoxes also be JRadioButtons that with the help of a second ButtonGroup object only allow one selection at a time?

Also:

• Get most all of that code out of the main method and into a Java class proper.
• If you are going to draw on a JPanel, you’ll need to subclass JPanel and override its paintComponent method. Inside of that method you’ll have if blocks that will change what is drawn depending on the state of your JRadioButtons. If this were my project, I’d have my main class extend JPanel and then draw in its paintComponent method. Then in my main method, I’d create a JFrame, and add an instance of this class into the JFrame’s contentPanel
• One solution is to simply call repaint() on the drawing JPanel in the ActionListener actionPerformed, and have the paintComponent method poll the JRadioButtons for their states and in if blocks decide what to draw.
• You’ll want to leave all mention of deadlines and urgencies out of your posts here as that is your problem not ours, and doesn’t help us help you to a solution. I have taken the liberty to remove this from your original post.