Question

I am using jLayeredPane in my Java GUI. I added some panels(jPanelsLayer1) on DEFAULT_LAYER of my jLayeredPane and also each jPanel has a MouseAdapter that Overrides mouseEntered and mouseExited for my purposes. When I add another components(jPanelsLayer2) on the PALETTE_LAYER of JlayerdePane, on the top of jPanelsLayer1, and defined MouseAdapter for them, I have problem. When mouse entered the common area mouseEntered and mouseExited of jPanels of different layers run consecutive several times. I want only jPanelslayer2 mouseAdapters to be active when they are seen on the top of jpanelLayer1. Maybe a solution be to remove jPanelLayer1 mouseAdapter. But this is not effective.

Please guid me…..sajad

Answer 1

I’m not sure where your problem is because when I test it, the mouse is only active in the Palette panel when it is above the Palette panel even if the the Palette panel is over the Default panel. For instance here is my SSCCE to test the concept. Feel free to modify this to show us your problem:

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.event.*;

import javax.swing.*;

@SuppressWarnings("serial")
public class LayeredFun extends JLayeredPane {
   private static final int JLP_WIDTH = 400;
   private static final int JLP_HEIGHT = 400;
   private static final Dimension PANEL_SIZE = new Dimension(200, 200);

   public LayeredFun() {
      JPanel defaultPanel = createPanel("Default Panel", new Point(10, 10), Color.cyan);
      JPanel palettePanel = createPanel("Palette Panel", new Point(100, 100), Color.pink);

      add(defaultPanel, JLayeredPane.DEFAULT_LAYER);
      add(palettePanel, JLayeredPane.PALETTE_LAYER);
   }

   private JPanel createPanel(String name, Point location, Color color) {
      JPanel defaultPanel = new JPanel();
      defaultPanel.setSize(PANEL_SIZE);
      defaultPanel.setLocation(location);
      MyMouseAdapter defaultMouseAdapater = new MyMouseAdapter(name);
      defaultPanel.addMouseListener(defaultMouseAdapater);
      defaultPanel.addMouseMotionListener(defaultMouseAdapater);
      defaultPanel.setBackground(color);
      defaultPanel.setBorder(BorderFactory.createTitledBorder(name));
      return defaultPanel;
   }

   @Override
   public Dimension getPreferredSize() {
      return new Dimension(JLP_WIDTH, JLP_HEIGHT);
   }

   private class MyMouseAdapter extends MouseAdapter {
      private String name;

      public MyMouseAdapter(String name) {
         this.name = name;
      }

      @Override
      public void mouseEntered(MouseEvent e) {
         System.out.printf("%s: mouseEntered%n", name);
      }

      @Override
      public void mouseExited(MouseEvent e) {
         System.out.printf("%s: mouseExited%n", name);
      }

      @Override
      public void mouseMoved(MouseEvent e) {
         System.out.printf("%s: mouseMoved%n", name);
      }
   }

   private static void createAndShowUI() {
      JFrame frame = new JFrame("LayeredFun");
      frame.getContentPane().add(new LayeredFun());
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      java.awt.EventQueue.invokeLater(new Runnable() {
         public void run() {
            createAndShowUI();
         }
      });
   }
}