Java Swing - Using JLayeredPane to show component in different overlapping layers

[Last Updated: Jul 21, 2018]

Following example shows the basic use of JLayeredPane.

JLayeredPane is a container which can be used to display its children components in different layers (depths). That allows the children to overlap with each other when needed.

Example

package com.logicbig.example;

import javax.swing.*;
import javax.swing.border.LineBorder;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

public class ExampleMain {
  public static void main(String[] args) {
      JFrame frame = createFrame();

      JLayeredPane layeredPane = new JLayeredPane();

      //adding a button to the JLayeredPane
      JButton button = new JButton("Show message");
      //need to do absolute positioning because by default LayeredPane has null layout,
      button.setBounds(100, 50, 150, 30);
      layeredPane.add(button, JLayeredPane.DEFAULT_LAYER);//depth 0

      //adding an initially invisible JLabel in an upper layer
      JLabel label = new JLabel("Test message");
      label.setOpaque(true);
      label.setHorizontalAlignment(SwingConstants.CENTER);
      //setting background with transparency value to see though the label
      label.setBackground(new Color(50, 210, 250, 200));
      //just set the size for now
      label.setSize(200, 50);
      label.setBorder(new LineBorder(Color.gray));
      label.setVisible(false);
      layeredPane.add(label, JLayeredPane.POPUP_LAYER);//depth 300

      //to make label visible
      button.addActionListener(e -> {
          JComponent source = (JComponent) e.getSource();
          //set the  popup label location at center of the source component
          label.setLocation(new Point(source.getX() + source.getWidth() / 2,
                  source.getY() + source.getHeight() / 2));
          label.setVisible(true);
      });

      //to hide the label
      frame.addMouseListener(new MouseAdapter() {
          @Override
          public void mousePressed(MouseEvent e) {
              label.setVisible(false);
          }
      });

      frame.add(layeredPane);
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
  }

  private static JFrame createFrame() {
      JFrame frame = new JFrame("JLayeredPane Basic Example");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.setSize(new Dimension(500, 400));
      return frame;
  }
}