textfieldtest.java

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// Fig. 13.7: TextFieldTest.java
// Demonstrating the JTextField class.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class TextFieldTest extends JFrame {
   private JTextField textField1, textField2, textField3;
   private JPasswordField passwordField;

   // set up GUI
   public TextFieldTest()
   {
      super( "Testing JTextField and JPasswordField" );

      Container container = getContentPane();
      container.setLayout( new FlowLayout() );

      // construct textfield with default sizing
      textField1 = new JTextField( 10 );
      container.add( textField1 );

      // construct textfield with default text
      textField2 = new JTextField( "Enter text here" );
      container.add( textField2 );

      // construct textfield with default text,
      // 20 visible elements and no event handler
      textField3 = new JTextField( "Uneditable text field", 20 );
      textField3.setEditable( false );
      container.add( textField3 );

      // construct passwordfield with default text
      passwordField = new JPasswordField( "Hidden text" );
      container.add( passwordField );

      // register event handlers
      TextFieldHandler handler = new TextFieldHandler();
      textField1.addActionListener( handler );
      textField2.addActionListener( handler );
      textField3.addActionListener( handler );
      passwordField.addActionListener( handler );

      setSize( 325, 100 );
      setVisible( true );

   } // end constructor TextFieldTest

   public static void main( String args[] )
   { 
      TextFieldTest application = new TextFieldTest();
      application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
   }

   // private inner class for event handling
   private class TextFieldHandler implements ActionListener {

      // process textfield events
      public void actionPerformed( ActionEvent event )
      {
         String string = "";

         // user pressed Enter in JTextField textField1
         if ( event.getSource() == textField1 )
            string = "textField1: " + event.getActionCommand();

         // user pressed Enter in JTextField textField2
         else if ( event.getSource() == textField2 )
            string = "textField2: " + event.getActionCommand();

         // user pressed Enter in JTextField textField3
         else if ( event.getSource() == textField3 )
            string = "textField3: " + event.getActionCommand();

         // user pressed Enter in JTextField passwordField
         else if ( event.getSource() == passwordField ) {
            string = "passwordField: " + 
               new String( passwordField.getPassword() );
         }

         JOptionPane.showMessageDialog( null, string );

      } // end method actionPerformed

   } // end private inner class TextFieldHandler

} // end class TextFieldTest