title: Switching JTextField when clicking a button
body: <blockquote>
    <p>I have got a JTextArea and a JTextField and now i want that if i click on JTextArea button the control shifts to JTextArea and
    when i click the JTextField button control shifts to JTextField. I am
    not getting anything to do such stuff.
    The program just changes the text in the JTextField based on the JRadioButton clicked.</p>
  </blockquote>
  
  <pre><code>   ***This is the code:***
  
  
  
  import java.awt.*;
      import java.awt.event.*;
      import javax.swing.*;
  
  
  public class prg_32 extends JPanel implements ItemListener{
  
      JTextArea a1;       
      JButton t1,t2;
      JRadioButton b1,b2,b3,b4;
      JTextField fld1;
      ButtonGroup grp;
      GridBagConstraints gbc = new GridBagConstraints();      //GridBagConstraints object
  
      public prg_32(){
          setLayout(new GridBagLayout());
  
          a1 = new JTextArea(3,10);       //TextArea
          gbc.gridx = 0;              
          gbc.gridy = 0;
          gbc.gridheight = 3;
          gbc.fill = GridBagConstraints.VERTICAL;
          add(a1,gbc);        //location of JTextArea
  
          t1 = new JButton("TextArea");
          gbc.gridx = 1;
          gbc.gridy = 0;
          gbc.gridheight = 1;
          add(t1,gbc);        //location of JButton
  
          t2 = new JButton("TextField");
          gbc.gridx = 2;
          gbc.gridy = 0;
          gbc.gridheight = 1;
          add(t2,gbc);        //location of JButton
  
          b1 = new JRadioButton("Bold",false);
          gbc.gridx = 1;
          gbc.gridy = 1;
          gbc.gridheight = 1;
          add(b1,gbc);
  
          b2 = new JRadioButton("Italic",false);
          gbc.gridx = 2;
          gbc.gridy = 1;
          gbc.gridheight = 1;
          add(b2,gbc);
  
          b3 = new JRadioButton("Plain",false);
          gbc.gridx = 1;
          gbc.gridy = 2;
          gbc.gridheight = 1;
          add(b3,gbc);
  
          b4 = new JRadioButton("Bold/Italic",true);
          gbc.gridx = 2;
          gbc.gridy = 2;
          gbc.gridheight = 1;
          add(b4,gbc);
  
          grp = new ButtonGroup();
          grp.add(b1);
          grp.add(b2);
          grp.add(b3);
          grp.add(b4);
  
          fld1 = new JTextField("enter your name");
          gbc.gridx = 0;
          gbc.gridy = 3;
          gbc.gridwidth = 3;
          gbc.fill = GridBagConstraints.HORIZONTAL;
          add(fld1,gbc);
  
          fld1.setFont(new Font("Serif",Font.BOLD + Font.ITALIC,14));
  
          b1.addItemListener(this);       //Event Handling
          b2.addItemListener(this);       //Event Handling
          b3.addItemListener(this);       //Event Handling
          b4.addItemListener(this);       //Event Handling
      }
  
      public void itemStateChanged(ItemEvent e) {
          Font font = null;
  
          if(b1.isSelected())
              font = new Font("Serif",Font.BOLD,14);
          else if(b2.isSelected())
              font = new Font("Serif",Font.ITALIC,14);
          else if(b3.isSelected())
              font = new Font("Serif",Font.PLAIN,14);
          else
              font = new Font("Serif",Font.BOLD + Font.ITALIC,14);
  
          fld1.setFont(font);
  
      }
  
      public static void main(String[] args){
          prg_32 px = new prg_32();
          JFrame jf = new JFrame();
  
          jf.setSize(500, 300);
          jf.setVisible(true);
          jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          jf.add(px);
      }
  
  }
  </code></pre>