Diable JList in JDialog at runtime

[png]

Hi,

I am facing a problem with JDialog. I have a JDialog(Modal) which have some panels and controls like- JList, JTextField, JButton etc.

I have two JList one is LstCategory and second is lstSubcategory. If the user select a category and that is valid, lstSubcategory will fill with some options. But if the category is not valid, lstSubcategory will be disabled.

I have used the methods like:

lstSubcategory.setEnabled(false);
or
ScrollSubCategory..setEnabled(false);

But no function is working.

What should be done to disable or enable lstSubcategory at run time?

[Eranga]

How did you do that, through an action listener? Can you show your code here?

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Hi,

I am doing that in the LstCategory SelectionChaged event. the code part is:

public class SaveDialog
{
   JDialog dlgSave;
  JList lstCategory,lstSubCategory;
  DefaultListModel lstModel, lstSubModel;
  JScrollPane scrollcategory, ScrollSubCategory;
  //Other controls
   ........................

  SaveDialog()
  {
    lstModel = new DefaultListModel( );
    lstSubModel = new DefaultListModel( );
    dlgSave = new JDialog();
    dlgSave.setTitle("Save Parameters");
    dlgSave.setModal(true);

    lstCategory = new JList(lstModel);
    lstSubCategory = new JList(lstSubModel);

    lstCategory.setSelectionMode(ListSelectionModel.SINGLE_SELECTION );
    lstCategory.addListSelectionListener(new javax.swing.event.ListSelectionListener(){
             public void valueChanged(ListSelectionEvent e) {
                LstCategorySelectionChanged(e);
            }
        } );
       scrollcategory = new JScrollPane(lstCategory);
       scrollcategory.setHorizontalScrollBar(null);
       scrollcategory.setBounds(3, 200, 180, 45);

      lstSubCategory.setSelectionMode(ListSelectionModel.SINGLE_SELECTION );
      ScrollSubCategory = new JScrollPane(lstSubCategory);
      ScrollSubCategory.setHorizontalScrollBar(null);
      ScrollSubCategory.setBounds(205, 200, 180, 45);

       // Fill category list with some values
       ...................................

       JPanel panel = new JPanel();
       panel.setLayout(null);
       panel.setPreferredSize(new Dimension(400,513));

       panel.add(scrollcategory);
       panel.add(ScrollSubCategory);
      // other controls and panels
     ....................
     dlgSave.add(panel);
    dlgSave.setResizable(false);
    dlgSave.setVisible(true);
  }  // close cunstructor

  // lst category selection changed event
  // if the user select a valid category, the lstsubcategory will fill up with some values
  // and enabled otherwise lstsubcategory will be disabled here
  void LstCategorySelectionChanged(ListSelectionEvent e)
    {
        int idx = lstCategory.getSelectedIndex();
        if(idx>=0)
        {
             if(!lstSubCategory.isEnabled())
                    lstSubCategory.setEnabled(true);  // not working

            if(lstSubModel.getSize()>0)
                lstSubModel.clear();

           // Check the selected value is valid, fill the subcategory
           if(valid)
          {
                  // fill the subcategory
                  ..........................
          } 
          else
           {
                lstSubCategory.setEnabled(false);  // not working
           }
        }
                    
     } // closing selection event
} // closing of the class

I am unable to find out where the problem is?

[Michael Dunn]

> What should be done to disable or enable lstSubcategory at run time?

worked OK for me

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I have find out where the problem was. Thanks to all.

[Eranga]

I have find out where the problem was. Thanks to all.

Nice to hear that you've solve the problem. And also if someone else comes with the quite similar issue, your comment may be really helpful. So why don't you send the solution here as well.

And also please use code tags when you posting code segments in the forum. Unformated codes are really hard to read. If you don't know how to do it, please look at the my forum signature. You can find the related link.