Question

I wrote a autocomplete combobox program in which I search for the words entered by the user inside a file. The program works fine, however, the combobox editor doesn’t return anything when something is typed in it. I don’t know why is that.. Here is the chunk of code that deals with the problem.

// in GUI class constructor
    InstantSearchBox = new JComboBox();
    InstantSearchBox.setEditable(true);

    /*****/
    KeyHandler handle = new KeyHandler();

    InstantSearchBox.getEditor().getEditorComponent().addKeyListener(handle);


// Keylistener class (KeyPressed method)
try
{
    dataTobeSearched = InstantSearchBox.getEditor ().getItem ().toString ();

    // the string variable is empty for some reason
    System.out.println ("Data to be searched " + dataTobeSearched); 
}
catch (NullPointerException e)
{
    e.printStackTrace ();
}

Regards

Answer 1

Don’t use a KeyListener. The text typed has not beeen added to the text field when at the time a keyPressed event is generated.

The better way to check for changes to the text field is to add a DocumentListener to the Document of the text field. See the section from the Swing tutorial on How to Write a Document Listener for more information.