JCheckBox MenuItem ActinListner的检查状态和取消检查状态

Question

I have WordWrap checkBox MenuItem.By default it is unchecked(false) state.When I run the program and click on New menuitem and write some text after I click on WordWrap menuItem,The WordWrap state in not changed for first two times.I want to change the state(checked) for first time only.I had tried that but not working. Here is code:

public class CheckBoxMenuItem extends javax.swing.JFrame {

int i=0;
JTextArea textArea;
JScrollPane scrollpane;
public CheckBoxMenuItem() {
    initComponents();
    WordWrap.setSelected(false);
}

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

    tabbedPane = new javax.swing.JTabbedPane();
    jMenuBar1 = new javax.swing.JMenuBar();
    jMenu1 = new javax.swing.JMenu();
    Create = new javax.swing.JMenuItem();
    WordWrap = new javax.swing.JCheckBoxMenuItem();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    jMenu1.setText("File");

    Create.setText("Create");
    Create.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            CreateActionPerformed(evt);
        }
    });
    jMenu1.add(Create);

    WordWrap.setSelected(true);
    WordWrap.setText("WordWrap");
    WordWrap.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            WordWrapActionPerformed(evt);
        }
    });
    jMenu1.add(WordWrap);

    jMenuBar1.add(jMenu1);

    setJMenuBar(jMenuBar1);

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addComponent(tabbedPane, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 400, Short.MAX_VALUE)
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addComponent(tabbedPane, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 279, Short.MAX_VALUE)
    );

    pack();
}// </editor-fold>                        

private void CreateActionPerformed(java.awt.event.ActionEvent evt) {                                       
   final JInternalFrame internalFrame = new JInternalFrame("");
    i++;
    internalFrame.setName("Document"+i);
    internalFrame.setClosable(true);
    internalFrame.setAutoscrolls(true);
    textArea=new JTextArea();
    textArea.setFont(new java.awt.Font("Miriam Fixed", 0, 13));
    scrollpane=new JScrollPane(textArea);
    internalFrame.add(scrollpane);
    tabbedPane.add(internalFrame);
    internalFrame.setSize(internalFrame.getMaximumSize());
    internalFrame.pack();
    internalFrame.setVisible(true);
}                                      

private void WordWrapActionPerformed(java.awt.event.ActionEvent evt) {                                         
    WordWrap.addItemListener(new ItemListener() {
        @Override
        public void itemStateChanged(ItemEvent ie) {
           AbstractButton button = (AbstractButton) ie.getItem();
           if(button.isSelected()){
              textArea.setLineWrap(true);
              scrollpane.validate(); 
           }
           else
           {
             textArea.setLineWrap(false);
             scrollpane.validate();  
           }
        }
    });
}                                        

public static void main(String args[]) {
    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */
    try {
        for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (ClassNotFoundException ex) {
        java.util.logging.Logger.getLogger(CheckBoxMenuItem.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(CheckBoxMenuItem.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(CheckBoxMenuItem.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(CheckBoxMenuItem.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        @Override
        public void run() {
            new CheckBoxMenuItem().setVisible(true);
        }
    });
}
// Variables declaration - do not modify                     
private javax.swing.JMenuItem Create;
private javax.swing.JCheckBoxMenuItem WordWrap;
private javax.swing.JMenu jMenu1;
private javax.swing.JMenuBar jMenuBar1;
private javax.swing.JTabbedPane tabbedPane;
// End of variables declaration                   

}

Answer 1

In your WordWrapActionPerformed method, you're doing nothing but adding an ItemListener to do, this won't do much...

Instead, you should simply carry out the requirements of the event, for example...

private void WordWrapActionPerformed(java.awt.event.ActionEvent evt) {
    AbstractButton button = (AbstractButton) evt.getSource();
    if (button.isSelected()) {
        textArea.setLineWrap(true);
    } else {
        textArea.setLineWrap(false);
    }
    textArea.revalidate();
}

Either that or change the listener on the menu item in the GUI properties to use a ItemListener instead of an ActionListener

You'll probably also want to become farmiluar with Code Conventions for the Java Programming Language , it will make your code eaiser to read for others ;)