Radiobutton actionmap problem

Question

I'm implementing a questionnaire consisting mainly of multiple choice questions.
To speed up inputting I want to bind keys to the radiobuttons (numpad 1 for the first option, 2 for the second etc...) All the questions are embedded in panels that are displayed as cards through the cardLayout.
But the keybindings only work for the first two cards (there are 30 questions/cards)? I don't understand why.
Can anyone help?
(Using Mnemonics results in exact the same problem but I don't want the user having to press the ALT-key.)
My (stripped) code :
The for loop that adds the radiobuttons to the panel (this panel is a card - for layout reasons its embedded in another panel) :
          for (Possibility possibility : question.getPossibilities()){
               possibilityRadioButton = new MultipleChoicePossibilityRadioButton();
               possibilityRadioButton.setBackground(QuestionPanel.BACKGROUND_COLOR);
               possibilityRadioButton.setFont(ANSWER_FONT);
               possibilityRadioButton.addActionListener(this);
               possibilityRadioButton.setActionCommand(ANSWER_SUBMITTED);
               KeyStroke keystroke = KeyStroke.getKeyStroke(NumpadKeys.get(question.getPossibilities().indexOf(possibility)),0);
               possibilityRadioButton.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).
                                                                 put(keystroke,ANSWER_SUBMITTED);
               possibilityRadioButton.getActionMap().put(ANSWER_SUBMITTED,
                         new AbstractAction() {
                              public void actionPerformed(ActionEvent ae) {
                                   ((MultipleChoicePossibilityRadioButton) ae.getSource())
                                             .doClick();
               c.gridy = layoutRow++;
               contentPanel.add(mogelijkheidRadioButton,c);
               buttonGroup.add(mogelijkheidRadioButton);
          }NumpadKeys is a static list :
     private final static ArrayList<Integer> NumpadKeys = new ArrayList<Integer>();
       static {
            NumpadKeys.add(KeyEvent.VK_NUMPAD1);
            NumpadKeys.add(KeyEvent.VK_NUMPAD2);
            NumpadKeys.add(KeyEvent.VK_NUMPAD3);
            NumpadKeys.add(KeyEvent.VK_NUMPAD4);
            NumpadKeys.add(KeyEvent.VK_NUMPAD5);
            NumpadKeys.add(KeyEvent.VK_NUMPAD6);
            NumpadKeys.add(KeyEvent.VK_NUMPAD7);
            NumpadKeys.add(KeyEvent.VK_NUMPAD8);
            NumpadKeys.add(KeyEvent.VK_NUMPAD9);
       }Edited by: Garfke on Jul 23, 2009 4:25 AM

Answer 1

You should submit an SSCCE to get a better chance of other people reproducing and debugging the problem.
However, based on your description I'd suspect one thing (which I can't check myself as you didn't provide an SSCCE):
From the Swing tutorial on [How to use key bindings|http://java.sun.com/docs/books/tutorial/uiswing/misc/keybinding.html] :
+If more than one binding exists for the key, only the first valid one found is used. Input maps are checked in this order: (...)
Because the order of searching the components is unpredictable, avoid duplicate WHEN_IN_FOCUSED_WINDOW bindings!+ (highlighting and exclamation marks are not mine, but are present as well in the tutorial!).
In your case, several JRadioButtons of the CardLayout have the same keystroke "1", "2",... bound (to the same action name, but that's irrelevant since once the action name is found, the action will be fetched from the component's ActionMap). All bindings are valid in the WHEN_IN_FOCUSED_WINDOW mode, and only the "first" one is returned.
As the order is unpredictable, it's probably only by chance that the "first" card's binding work. I don't get why the first and second both work, although I suspect the ordering or the search may be affected by the cardLayout swapping the cards, with no guarantee of the current card being the first one searched. Indded the javadoc for CardLayout.show(...) makes no such provision.
Edited by: jduprez on Jul 23, 2009 12:18 PM - added note on action name being the same
Edited by: jduprez on Jul 23, 2009 12:22 PM - and on cardLayout.show()