Question

I have write a program which is suppose the set the application property. I am using JSplit Pane with JScrollPane. Program is loading fine but it is not changing the value of the right panel in response to list element on the left. Please let me know if I am doing anything wrong. I have refered following program

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JDialog;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTabbedPane;
import javax.swing.ListSelectionModel;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

public class ApplicationPropertyDlg extends JDialog implements ActionListener,ListSelectionListener {

   private DButton     pb_OK           = null ;
   private DButton     pb_CANCEL       = null ;
   private DButton     pb_APPLY        = null ;
   private String[]         appProp     = null;
   private JList            appList     = null;
   private JSplitPane       appPanel    = null;
   private JScrollPane      listScrollPanel,appScrollPanel  = null; 

   public ApplicationPropertyDlg ( AppDefaultWin parent ) {
      super ( parent, "Properties Application", true ) ;
      initializeAppProp();
      intializeAppList();
      initializeGUI();
      ButtonPanel buttonPanel = new ButtonPanel () ;
      setSize ( 800,700 ) ;
      WinUtil.centerChildInParent ( this, parent ) ;          
      pb_OK     = new JButton ( ) ;
      pb_APPLY  = new JButton ( ) ;
      pb_CANCEL = new JButton ( ) ;

      pb_OK.addActionListener ( this ) ;
      pb_APPLY.addActionListener ( this ) ;
      pb_CANCEL.addActionListener ( this ) ;
      GUISystem.setPreferredButton ( pb_OK ) ;
      GUISystem.setPreferredButton ( pb_CANCEL ) ;
      GUISystem.setPreferredButton ( pb_APPLY ) ;
      getContentPane().setLayout ( new BorderLayout (5,5) ) ;
      getContentPane().add(appPanel);
      getContentPane().add ( buttonPanel, BorderLayout.SOUTH ) ;
      buttonPanel.add ( pb_OK ) ;
      buttonPanel.add ( pb_APPLY ) ;
      buttonPanel.add ( pb_CANCEL ) ;                                 
      setVisible ( true ) ;   
   }

   private void initializeGUI() {
    // TODO Auto-generated method stub
       listScrollPanel = new JScrollPane(appList);
       appScrollPanel = new JScrollPane(new GeneralPage());
       appPanel = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,listScrollPanel,appScrollPanel);
       appPanel.setOneTouchExpandable(true);
       appPanel.setDividerLocation(200);
       //minimum size for individual Panel
       Dimension minimumSize = new Dimension(100, 50);
       listScrollPanel.setMinimumSize(minimumSize);
       appScrollPanel.setMinimumSize(minimumSize);
       //Provide a preferred size for the split pane.
       appPanel.setPreferredSize(appPanel.getPreferredSize());     

}


private void intializeAppList() {
    // TODO Auto-generated method stub
       appList = new JList(appProp);
       appList.setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SELECTION);
       appList.setSelectedIndex(0);
       appList.addListSelectionListener(this);


}





private void initializeAppProp() {
    // TODO Auto-generated method stub
    appProp = new String []{"General","Task Bar", "Look and Feel","Country"};
}

   public void propertyChanged ( int property, Object value ) {
      if ( property == PropertySystem.PROPERTY_LANGUAGE )
         setText() ;
      else if ( property == PropertySystem.PROPERTY_LAF )
         GUISystem.setLookAndFeel ( this ) ;
      else
         GUISystem.setPropertiesOnPanel ( getContentPane() ) ;
   }




   public void actionPerformed ( ActionEvent e ) {
         dispose() ;
   }



@Override
public void valueChanged(ListSelectionEvent e) {
    // TODO Auto-generated method stub
    JList list = (JList)e.getSource();
    updateAppPanel(appProp[list.getSelectedIndex()]);

}

private void updateAppPanel(String panelName) {
    // TODO Auto-generated method stub
    if(panelName.equalsIgnoreCase("General"){
        appScrollPanel.removeAll();
        appScrollPanel.add(new GeneralPage());
    }
    else if (panelName.equalsIgnoreCase("Task Bar"){
        appScrollPanel.removeAll();
        appScrollPanel.setViewportView(new TaskBarPage());
    }
    else if (panelName.equalsIgnoreCase("Language"){
        appScrollPanel.removeAll();
        appScrollPanel.setViewportView(new LanguagePage());
    }
    else if (panelName.equalsIgnoreCase("Look and Feel"){
        appScrollPanel.removeAll();
        appScrollPanel.setViewportView(new LookFeelPage());
    }
    else if (panelName.equalsIgnoreCase("Country"){
        appScrollPanel.removeAll();
        appScrollPanel.setViewportView(new SelectCountryPage());
    }
    appScrollPanel.revalidate();
    appScrollPanel.repaint();   
    }
} 

Answer 1

First, add a new control container to the class (preferable a JPanel):

    ...
    private JSplitPane       appPanel    = null;
    private JScrollPane      listScrollPanel,appScrollPanel  = null;
    // End of your controls...

    private JPanel tabContainer;   

Then, in the code section where your code initialize the appScrollPanel variable, instead of passing a new instance of a GeneralPane, pass the tabContainer like this:

     tabContainer = new JPanel();
     tabContainer.setLayout(new CardLayout());
     tabContainer.add(new GeneralPage());
     // Instead of adding GeneralPane directly, add the GeneralPane container
     appScrollPanel = new JScrollPane(tabContainer);

Then, in the updateAppPanel method, replace the appScrollPanel.setViewportView invocations like this:

private void updateAppPanel(String panelName) {
    // TODO Auto-generated method stub
    if(panelName.equalsIgnoreCase("General")){
        tabContainer.removeAll();
        tabContainer.add(new GeneralPage());
    } 
    else if (panelName.equalsIgnoreCase("Task Bar")){
        tabContainer.removeAll();
        tabContainer.add(new TaskBarPage());
    }
    else if (panelName.equalsIgnoreCase("Language")){
        tabContainer.removeAll();
        tabContainer.add(new LanguagePage());
    }
    else if (panelName.equalsIgnoreCase("Look and Feel")){
        tabContainer.removeAll();
        tabContainer.add(new LookFeelPage());
    } 
    else if (panelName.equalsIgnoreCase("Country")){
        tabContainer.removeAll();
        tabContainer.add(new CountryPage());
    }
    appScrollPanel.revalidate();
    appScrollPanel.repaint();   
}

And it should work:

May I suggest you to put the updateAppPanel code inside a loop? It could save some trouble if you need to make a modification to the inner body of every else if block