Thread: CardLayout does not show my content

I have a JFrame, a JSplitPane as the container of the frame.
On the left side of the splitpane, there are two radio buttons (more to come, but I am stuck).
On the right side, there is a CardLayout. This CardLayout has two 'cards' (JPanels, actually). And to test if it shows the panels when I switch them, I put one checkbox each.

But it does not show anything. I cannot think anything to do. I tried to put only the checkboxes thinking maybe it only accepts components, but it didn't work.

This is the GUI class I have. I have commented what I am trying to do so that you don't have to read everything. Also, it does not have the imports and it is started from another class.
Since I am just testing, I created a project for this, so the main class main method just starts this.

public class SolveSomehow extends JFrame{
 
		private JSplitPane splitPane;
		private JPanel leftPanel,rightPanel,panelOne,panelTwo;
		private JCheckBox cbTwo,cbOne,cbCardOne,cbCardTwo;
		private CardLayout cardLay;
 
		private final String ONE = "PanelOne";
		private final String TWO = "PanelTwo";
 
		public SolveSomehow() {
			setResizable(false);
			setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
			setBounds(100, 100, 450, 300);
			// I use WindowBuilder as GUI designer and it had a JPanel as the container.
			// I deleted and added splitPane.
			splitPane = new JSplitPane();
			splitPane.setResizeWeight(0.5);
			setContentPane(splitPane);
 
 
			//Next 6 lines I put panels to the left and right side of the splitpane.
			leftPanel = new JPanel();
			splitPane.setLeftComponent(leftPanel);
			leftPanel.setLayout(null); //WindowBuilder made this null but it actually has absoluteLayout
 
			rightPanel = new JPanel();
			splitPane.setRightComponent(rightPanel);
 
			// I have to define the cardLay before the rightPanel, or else it does not recognize it
			// as the parent. [show(Container parent, String name);]
			cardLay = new CardLayout(0, 0);
			rightPanel.setLayout(cardLay);
 
			//Next 6 lines are about the left side of the splitPane. I add my checkboxes
			cbTwo = new JCheckBox("Box Two");
			cbTwo.setBounds(6, 7, 97, 23);
			leftPanel.add(cbTwo);
 
			cbOne = new JCheckBox("Box One");
			cbOne.setBounds(6, 34, 97, 23);
			leftPanel.add(cbOne);
 
			// The two panels I try to add to the cardLayout.
			panelOne = new JPanel(new FlowLayout());
			panelTwo = new JPanel(new FlowLayout());
 
 
			// Adding the checkboxes to the panels before adding them into the cardlayout.
			cbCardOne = new JCheckBox("Panel One");
			cbCardTwo = new JCheckBox("Panel Two");
 
			//Finally, boxes are added to the panel
			panelOne.add(cbCardOne);
			panelTwo.add(cbCardTwo);
 
			//Panels are added to the cardLayout
			cardLay.addLayoutComponent(panelOne, ONE);			
			cardLay.addLayoutComponent(panelTwo, TWO);
 
			//I want it to show the relevant panel when the checkbox gets the focus. 
			//So I wrote this Focus Adapter.
			cbTwo.addFocusListener(new FocusAdapter(){
				@Override
				public void focusGained(FocusEvent arg0) {
					System.out.println("Did it change?"); //Testing if 'focus' is what I thought,
					cardLay.show(rightPanel, ONE);		//And it is what I thought.
				}
			});
 
			cbOne.addFocusListener(new FocusAdapter(){
				@Override
				public void focusGained(FocusEvent arg0) {
					System.out.println("Didn't it change?");
					cardLay.show(rightPanel, TWO);
				}
			});
 
		}
	}

What am I doing wrong?

Norm, I hope this is enough for you to help me. The attached file includes my source file and a compiled app. The source and app only have the codes about the CardLayout.

Okay. This is my main class, only calls the GUI:

public class SolveHere {
 
	public static void main(String[] args) {
		SolveSomehow m = new SolveSomehow();
		m.setVisible(true);
 
	}
}

This is the SolveSomehow class, which creates the GUI:

import java.awt.CardLayout;
import java.awt.FlowLayout;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSplitPane;
 
public class SolveSomehow extends JFrame{
 
 
		private static final long serialVersionUID = 10277105675385182L;
		private JSplitPane splitPane;
		private JPanel leftPanel,rightPanel,panelOne,panelTwo;
		private JCheckBox cbTwo,cbOne,cbCardOne,cbCardTwo;
		private CardLayout cardLay;
 
		private final String ONE = "PanelOne";
		private final String TWO = "PanelTwo";
 
		public SolveSomehow() {
			setResizable(false);
			setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
			setBounds(100, 100, 450, 300);
			// I use WindowBuilder as GUI designer and it had a JPanel as the container.
			// I deleted and added splitPane.
			splitPane = new JSplitPane();
			splitPane.setResizeWeight(0.5);
			setContentPane(splitPane);
 
 
			//Next 6 lines I put panels to the left and right side of the splitpane.
			leftPanel = new JPanel();
			splitPane.setLeftComponent(leftPanel);
			leftPanel.setLayout(null); //WindowBuilder made this null but it actually has absoluteLayout
 
			rightPanel = new JPanel();
			splitPane.setRightComponent(rightPanel);
 
			// I have to define the cardLay before the rightPanel, or else it does not recognize it
			// as the parent. [show(Container parent, String name);]
			cardLay = new CardLayout(0, 0);
			rightPanel.setLayout(cardLay);
 
			//Next 6 lines are about the left side of the splitPane. I add my checkboxes
			cbTwo = new JCheckBox("Box Two");
			cbTwo.setBounds(6, 7, 97, 23);
			leftPanel.add(cbTwo);
 
			cbOne = new JCheckBox("Box One");
			cbOne.setBounds(6, 34, 97, 23);
			leftPanel.add(cbOne);
 
			// The two panels I try to add to the cardLayout.
			panelOne = new JPanel(new FlowLayout());
			panelTwo = new JPanel(new FlowLayout());
 
 
			// Adding the checkboxes to the panels before adding them into the cardlayout.
			cbCardOne = new JCheckBox("Panel One");
			cbCardTwo = new JCheckBox("Panel Two");
 
			//Finally, boxes are added to the panel
			panelOne.add(cbCardOne);
			panelTwo.add(cbCardTwo);
 
			//Panels are added to the cardLayout
			cardLay.addLayoutComponent(panelOne, ONE);			
			cardLay.addLayoutComponent(panelTwo, TWO);
 
			//I want it to show the relevant panel when the checkbox gets the focus. 
			//So I wrote this Focus Adapter.
			cbTwo.addFocusListener(new FocusAdapter(){
				@Override
				public void focusGained(FocusEvent arg0) {
					System.out.println("Did it change?"); //Testing if 'focus' is what I thought, And it is what I thought.
					cardLay.show(rightPanel, ONE);		// But it does not show anything on the right side.
				}
			});
 
			cbOne.addFocusListener(new FocusAdapter(){
				@Override
				public void focusGained(FocusEvent arg0) {
					System.out.println("Didn't it change?");
					cardLay.show(rightPanel, TWO);
				}
			});
 
		}
	}

I hope this helps you help me

Damn...
It is obvious now of course but... I thought the CardLayout is a little different than others and so I do not need this:

			rightPanel.add(panelOne);
			rightPanel.add(panelTwo);

I mean, I normally do add components to panels (or any other containers), not to layout, but CardLayout sounded a little different...
OK this was stupid.

Added the code. It works.

Thank you.