need help in applying inputverifer to jtextfield

[Mohit G Gupta]

[b]1.facing problem in applying input verifier to JTextfield[/b]

main class
VerifierTest

  

 import java.awt.*;
 import java.util.*;
 import java.awt.event.*;
 import javax.swing.*;
 

 public class VerifierTest extends JFrame {
 	 JDialog p;
     public VerifierTest() {
         JTextField tf1 = new JTextField ("Type \"pass\" here");
 	   getContentPane().add (tf1, BorderLayout.NORTH);
 	   
 	   tf1.setInputVerifier(new NotEmptyValidator(parent, tf1, "Field cannot be null."));
 	   JTextField tf2 = new JTextField ("TextField2");
 	   getContentPane().add (tf2, BorderLayout.SOUTH);
 
 	   WindowListener l = new WindowAdapter() {
 	       public void windowClosing(WindowEvent e) { 
 	           System.exit(0); 
 	       }
 	   };
 	   addWindowListener(l);
     }
 
     
 
     public static void main(String[] args) {
         Frame f = new VerifierTest();
 	   f.pack();
 	   f.setVisible(true);
     }
 }
 
 
 
  

NotEmptyValidator.java

  import javax.swing.JComponent;
import javax.swing.JTextField;
import javax.swing.JDialog;
 

 
public class NotEmptyValidator extends AbstractValidator {
    public NotEmptyValidator(JDialog parent, JTextField c, String message) {
        super(parent, c, message);
    }
	
    protected boolean validationCriteria(JComponent c) {
        if (((JTextField)c).getText().equals(""))
            return false;
        return true;
    }
}  

AbstractValidator -extended by NotEmptyValidator

  

  
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public abstract class AbstractValidator extends InputVerifier implements KeyListener {
    private JDialog popup;
    private Object parent;
    private JLabel messageLabel;
    private JLabel image;
    private Point point;
    private Dimension cDim;
    private Color color;
	
    private AbstractValidator() {
        color = new Color(243, 255, 159);
    }
	
    private AbstractValidator(JComponent c, String message) {
        this();
        c.addKeyListener(this);
        messageLabel = new JLabel(message + " ");
        image = new JLabel(new ImageIcon("exception_16x16.png"));
    }
	
    /**
     * @param parent A JDialog that implements the ValidationCapable interface.
     * @param c The JComponent to be validated.
     * @param message A message to be displayed in the popup help tip if validation fails.
     */
	
    public AbstractValidator (JDialog parent, JComponent c, String message) {		
        this(c, message);
        this.parent = parent;
        popup = new JDialog(parent);
        initComponents();
    }
	
    /**
     * @param parent A JFrame that implements the ValidationCapable interface.
     * @param c The JComponent to be validated.
     * @param message A message to be displayed in the popup help tip if validation fails.
     */
	
    public AbstractValidator (JFrame parent, JComponent c, String message) {
        this(c, message);
        this.parent = parent;
        popup = new JDialog(parent);
        initComponents();
    }
	
    /**
     * Implement the actual validation logic in this method. The method should
     * return false if data is invalid and true if it is valid. It is also possible
     * to set the popup message text with setMessage() before returning, and thus
     * customize the message text for different types of validation problems.
     * 
     * @param c The JComponent to be validated.
     * @return false if data is invalid. true if it is valid.
     */
	
    protected abstract boolean validationCriteria(JComponent c);
	
    /**
     * This method is called by Java when a component needs to be validated.
     * It should not be called directly. Do not override this method unless
     * you really want to change validation behavior. Implement
     * validationCriteria() instead.
     */
	
    public boolean verify(JComponent c) {		
        if (!validationCriteria(c)) {
			
            if(parent instanceof WantsValidationStatus)
                ((WantsValidationStatus)parent).validateFailed();
			
            c.setBackground(Color.PINK);
            popup.setSize(0, 0);
            popup.setLocationRelativeTo(c);
            point = popup.getLocation();
            cDim = c.getSize();
            popup.setLocation(point.x-(int)cDim.getWidth()/2,
                point.y+(int)cDim.getHeight()/2);
            popup.pack();
            popup.setVisible(true);
            return false;
        }
        
        c.setBackground(Color.WHITE);
		
        if(parent instanceof WantsValidationStatus)
            ((WantsValidationStatus)parent).validatePassed();
		
        return true;
    }
	
    /**
     * Changes the message that appears in the popup help tip when a component's
     * data is invalid. Subclasses can use this to provide context sensitive help
     * depending on what the user did wrong.
     * 
     * @param message
     */
	
    protected void setMessage(String message) {
       messageLabel.setText(message);
    }
	
     /**
      * @see KeyListener
      */
	
    public void keyPressed(KeyEvent e) {
        popup.setVisible(false);
    }
	
    /**
     * @see KeyListener
     */
	
    public void keyTyped(KeyEvent e) {}
	
    /**
     * @see KeyListener
     */
	
    public void keyReleased(KeyEvent e) {}
	
    private void initComponents() {
        popup.getContentPane().setLayout(new FlowLayout());
        popup.setUndecorated(true);
        popup.getContentPane().setBackground(color);
        popup.getContentPane().add(image);
        popup.getContentPane().add(messageLabel);
        popup.setFocusableWindowState(false);
    }
}
 

  

interface

   public interface WantsValidationStatus {
    void validateFailed();  // Called when a component has failed validation.
    void validatePassed();  // Called when a component has passed validation.
} 

when i run the VerifierTest after compling all other files,i get the following error


VerifierTest.java:19: parent is not public in java.awt.Component; cannot be accessed from outside package
tf1.setInputVerifier(new NotEmptyValidator(parent, tf1, "Field cannot be null."));
^
VerifierTest.java:19: cannot find symbol
symbol : constructor NotEmptyValidator(java.awt.Container,javax.swing.JTextField,java.lang.String)
location: class NotEmptyValidator
tf1.setInputVerifier(new NotEmptyValidator(parent, tf1, "Field cannot be null."));
^
2 errors


can anyone correct the code .i have tried to change the call
tf1.setInputVerifier(new NotEmptyValidator(parent, tf1, "Field cannot be null."));

to

tf1.setInputVerifier(new NotEmptyValidator((JDialog)parent, tf1, "Field cannot be null."));

but still the error comes

i would be grateful if somebody removes this error as i need for my college project


and

2.i tried the following change

if((tf.getText()).length()==1)
               { tf.setBackground(Color.PINK);
                 JOptionPane.showMessageDialog(null,"Invalid Customer code");
                   return true;}
               else{return false;}    

no optionPane or color of textfield changes

[Rob Spoor]

Please stick to your old thread. UseOneThreadPerQuestion. I've already shown you why it fails there - parent resolves to the private (or package default) field of java.awt.Component. You need to have a JDialog and use that as the first parameter.

Closing this thread.