Question

I have a Game Window to which I am trying to put W, A, S and D as scroll keys for the JScrollPane. This is what I have done so far on the method that runs it. The JScrollPane is not local. When I run it, the program runs fine but, the keys don’t do anything. I tried it with putting a breakpoint inside the action, so that it would run when it was responding to a button push but it didn’t do anything.
I would appreciate any input, let me know if you need more information.

/**
 * This sets all the key commands to the scroll pane for up, down, left, right.
 * These are W, S, A, D
 * It also sets the increment amount.
 */
private void setupScrollKeys()
{
    //sets up the scroll panes unit increment.
    final int increment = 80;
    scrollPane.getHorizontalScrollBar().setUnitIncrement(increment);
    scrollPane.getVerticalScrollBar().setUnitIncrement(increment);

    //set all the keyStrokes for up, down, left, right on the scroll pane.
    KeyStroke kUp = KeyStroke.getKeyStroke(KeyEvent.VK_W, 0);
    KeyStroke kDown = KeyStroke.getKeyStroke(KeyEvent.VK_S, 0);
    KeyStroke kLeft = KeyStroke.getKeyStroke(KeyEvent.VK_A, 0);
    KeyStroke kRight = KeyStroke.getKeyStroke(KeyEvent.VK_D, 0);

    // set W for key up.
    scrollPane.getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT)
                                                        .put(kUp, "keyUp");
    scrollPane.getActionMap().put("keyUp", new AbstractAction() 
    {
        public void actionPerformed(ActionEvent e) 
        {
            final JScrollBar bar = scrollPane.getVerticalScrollBar();
            int currentValue = bar.getValue();
            bar.setValue(currentValue - increment);
        }
    });
}

Answer 1

Try changing the line

 scrollPane.getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT)
                                                    .put(kUp, "keyUp");

to

scrollPane.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW)
                                                        .put(kUp, "keyUp");

I had no idea of key bindings, so I found this tutorial really handy.
How to Use Key Bindings