Add new fields with press of a button

Question

I´m creating a program in NetBeans where the user can create their own CSV-file. I've made a GUI. When I press the button, I want a new JLabel and a new JTextField to appear underneath the existing ones, for as many times as the button is pressed. How do I do that?

Answer 1

I've done something similiar and I'm using a JPanel with GroupLayout to solve this problem and that's my code:

EDIT - Your question aroused my interest and I've changed my code to your needs (of course only the basic, you will have to improve it)

---

Global variables

private GroupLayout m_layout;
private SequentialGroup m_verticalSg;
private ArrayList<Component> m_labelList;
private ArrayList<Component> m_textFieldList;
private ParallelGroup m_horizontalPgLabels;
private ParallelGroup m_horizontalPgTextfields;

---

Method createLayout()

Creates the layout for your panel which should contain the label & textfield components

private void createLayout()
{
   m_layout = new GroupLayout(YOUR_PANEL);
   YOUR_PANEL.setLayout(m_layout);

   //This SequentialGroup is used for the VerticalGroup
   m_verticalSg = m_layout.createSequentialGroup();
   m_verticalSg.addContainerGap();

   //Two ParallelGroups are used. One for all labels and the other one for all textfields
   m_horizontalPgLabels = m_layout.createParallelGroup(GroupLayout.Alignment.LEADING);
   m_horizontalPgTextfields = m_layout.createParallelGroup(GroupLayout.Alignment.LEADING);

   //These component lists are used for linkSize() -> Equalize components width
   m_labelList = new ArrayList<>();
   m_textFieldList = new ArrayList<>();

   m_layout.setHorizontalGroup(m_layout.createParallelGroup()
                    .addGroup(m_layout.createSequentialGroup()
                    .addContainerGap()
                    .addGroup(m_horizontalPgLabels)
                    .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED) //Create gap between horizontal groups
                    .addGroup(m_horizontalPgTextfields)
                    .addContainerGap()));

   m_layout.setVerticalGroup(m_layout.createParallelGroup().addGroup(m_verticalSg.addContainerGap()));
}

---

Method addNewRow()

Call this method from your button click event

private void addNewRow()
{
   if(m_layout == null)
      createLayout();

   Dimension dimLabel = new Dimension(100, 15);
   Dimension dimTextfield = new Dimension(200, 20);

   //Create a new label
   JLabel lbl = new JLabel();
   lbl.setText("Your text");
   lbl.setIcon(null/*Your icon*/);
   lbl.setSize(dimLabel);
   lbl.setPreferredSize(dimLabel);

   //Create a new textfield
   JTextField txtField = new JTextField();
   txtField.setSize(dimTextfield);
   txtField.setPreferredSize(dimTextfield);

   //Add components to arrays and increase index
   m_labelList.add(lbl);
   m_textFieldList.add(txtField);

   //Create new ParallelGroup for the vertical SequentialGroup
   ParallelGroup newVerticalParallelGroup = m_layout.createParallelGroup(GroupLayout.Alignment.LEADING);
   newVerticalParallelGroup.addComponent(lbl);
   newVerticalParallelGroup.addComponent(txtField);
   m_verticalSg.addGroup(newVerticalParallelGroup);
        m_verticalSg.addPreferredGap(LayoutStyle.ComponentPlacement.RELATED);

   //Add the new label to the horizontal label group
   m_horizontalPgLabels.addComponent(lbl, GroupLayout.Alignment.CENTER);
   //Add the new textfield to the horizontal textfield group
   m_horizontalPgTextfields.addComponent(txtField);

   m_layout.linkSize(SwingConstants.HORIZONTAL, m_labelList.toArray(new Component[m_labelList.size()]));
   m_layout.linkSize(SwingConstants.HORIZONTAL, m_textFieldList.toArray(new Component[m_textFieldList.size()]));
}

---

The last step is to add an ActionListener to your button to call the method addNewRow().

jButton1.addActionListener(new ActionListener()
{
    @Override
    public void actionPerformed(ActionEvent e)
    {
       addNewRow();
    }
});

Feel free to ask me if something is unclear.