CODEWITHSUNDEEP
javaswtlistener
Laishram Krishnananda Singh
Laishram Krishnananda Singh

Reputation: 87

Conflict between VerifyListener and FocusListener

There is a SWT text box. I am setting a default text on it.

  1. A focus listener is set so that when the focus is on the text box, the default text is deleted.

  2. A verify listener is set to make sure only alphabet is entered.

However, the text is not set to empty when focus is set on the text box. What is causing this problem?

final Text text = new Text(parent, SWT.NONE);
text.setText("Default");
text.addFocusListener( new FocusAdapter() {
     @Override
     public void focusGained(FocusEvent event) {
           if("Default".equals(text.getText())){
           text.setText("");
           }
     }
});
text.addVerifyListener( new VerifyListener() {
     @Override
     public void verifyText(VerifyEvent e) {
            e.doit = Verifier.isAlphabet(e.character);
     }
 });

Upvotes: 0

Views: 60

Answers (2)

Loris Securo
Loris Securo

Reputation: 7638

Text already has support for default text via the method setMessage.

So, instead of using setText("Default") and the focus listener you could just use setMessage("Default");.

The verify listener should work correctly with it.

Upvotes: 2

greg-449
greg-449

Reputation: 111142

When your focus listener calls text.setText("") the verify listener is called. In this case the value of e.character is 0 because no character is being added. Presumably your Verifier.isAlphabet method is returning false for this and stopping the change from happening.

Your verify listener should not be testing the character value. You should be looking at the VerifyEvent text field which gives you the full text being changed (you may also need to look at the start and end fields).

Upvotes: 0

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