mouseListener仅识别JLabel

Question

I added a mouseListener on a JPanel which contains several components. To test the mouseListener I only setBorder of the Jpanel when entering and exit the jpanel. The problem is, it only recognizes the mouse event on the jlabels of the jpanel, not on other components or the main jpanel itself. Can't figure out why...

here's the code :

     import javax.swing.JFrame;


public class compte2 extends javax.swing.JPanel {


    public compte2() {
        initComponents();
    }


    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        jLabel1 = new javax.swing.JLabel();
        jLabel3 = new javax.swing.JLabel();
        jButton2 = new javax.swing.JButton();
        jPanel2 = new javax.swing.JPanel();
        jLabel4 = new javax.swing.JLabel();
        jLabel6 = new javax.swing.JLabel();
        jButton1 = new javax.swing.JButton();
        jScrollPane1 = new javax.swing.JScrollPane();

        setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED));
        setPreferredSize(new java.awt.Dimension(240, 160));
        addMouseListener(new java.awt.event.MouseAdapter() {
            public void mouseEntered(java.awt.event.MouseEvent evt) {
                formMouseEntered(evt);
            }
            public void mouseExited(java.awt.event.MouseEvent evt) {
                formMouseExited(evt);
            }
        });
        setLayout(new java.awt.BorderLayout());

        jPanel1.setMinimumSize(new java.awt.Dimension(100, 56));
        jPanel1.setPreferredSize(new java.awt.Dimension(400, 56));
        jPanel1.setLayout(new java.awt.BorderLayout());

        jLabel1.setFont(new java.awt.Font("Tahoma", 1, 18)); // NOI18N
        jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        jLabel1.setText("CLUB");
        jLabel1.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED));
        jLabel1.setPreferredSize(new java.awt.Dimension(240, 28));
        jPanel1.add(jLabel1, java.awt.BorderLayout.PAGE_START);

        jLabel3.setFont(new java.awt.Font("Tahoma", 1, 18)); // NOI18N
        jLabel3.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        jLabel3.setText("ILLIMITE");
        jLabel3.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED));
        jLabel3.setPreferredSize(new java.awt.Dimension(190, 28));
        jPanel1.add(jLabel3, java.awt.BorderLayout.CENTER);

        jButton2.setIcon(new javax.swing.ImageIcon("C:\\Users\\pc\\Downloads\\icon\\Pics\\see.png")); // NOI18N
        jButton2.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED));
        jButton2.setMinimumSize(new java.awt.Dimension(28, 28));
        jButton2.setPreferredSize(new java.awt.Dimension(28, 28));
        jPanel1.add(jButton2, java.awt.BorderLayout.LINE_END);

        add(jPanel1, java.awt.BorderLayout.PAGE_START);

        jPanel2.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));
        jPanel2.setMinimumSize(new java.awt.Dimension(100, 28));
        jPanel2.setPreferredSize(new java.awt.Dimension(400, 28));
        jPanel2.setLayout(new java.awt.BorderLayout());

        jLabel4.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        jLabel4.setText("€");
        jLabel4.setPreferredSize(new java.awt.Dimension(15, 28));
        jPanel2.add(jLabel4, java.awt.BorderLayout.LINE_END);

        jLabel6.setHorizontalAlignment(javax.swing.SwingConstants.RIGHT);
        jLabel6.setText("0,00");
        jLabel6.setMaximumSize(new java.awt.Dimension(50, 28));
        jLabel6.setPreferredSize(new java.awt.Dimension(50, 28));
        jPanel2.add(jLabel6, java.awt.BorderLayout.CENTER);

        jButton1.setText("ENCAISSER");
        jButton1.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED));
        jButton1.setMinimumSize(new java.awt.Dimension(80, 28));
        jButton1.setPreferredSize(new java.awt.Dimension(80, 28));
        jPanel2.add(jButton1, java.awt.BorderLayout.LINE_START);

        add(jPanel2, java.awt.BorderLayout.PAGE_END);
        add(jScrollPane1, java.awt.BorderLayout.CENTER);
    }// </editor-fold>                        

    private void formMouseEntered(java.awt.event.MouseEvent evt) {                                  
        compte2 mc = (compte2)evt.getSource();
    mc.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(204, 0, 0), 4));
    }                                 

    private void formMouseExited(java.awt.event.MouseEvent evt) {                                 
       compte2 mc = (compte2)evt.getSource();
    mc.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));
    }                                


    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton2;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel jLabel6;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPanel jPanel2;
    private javax.swing.JScrollPane jScrollPane1;
    // End of variables declaration                   



    public static void main(String[] args) {

        JFrame j = new JFrame();
        compte2 mc = new compte2();
        j.add(mc);
        j.pack();
        j.setVisible(true);
}

}

Answer 1

You problem is that you add child panels to the main panel you your events are not being generated at you expect.

Add some debug code to your mouseEntered/Exited methods so you can see when the events are generated.

Change your code to give you panel a background color so you can see when the mouse enters/exits the panel:

initComponents();
addMouseListener(this);
setBackground(Color.YELLOW);

I never use the IDE to generate code and I have no idea what the GroupLayout is doing. So you are getting the weird behaviour because there are gaps between the child components. So you see changes as you move the mouse vertically between panels.

The buttons and labels are added to the child components so they should not generate events if you mouse the mouse horizontally on the child panel.