Question

It seems that JButton doesn’t automatically receive the focus when clicked, unless I explicitly configured the button with .setRequestFocusEnabled(true). The application I’m working with has a lot of buttons created in many different places (i.e. not via a factory method), and I need all of them to request the focus when clicked.

Is there an easy way to change the default behavior so that buttons request the focus on click by default, for example by setting some property? Or I need to hunt ’em all down and call .setRequestFocusEnabled(true) on each button one by one?

Answer 1

A JButton should get the focus when clicked. You have probably buttons that have been modified to not do that. However that doesn’t solve yoir problem.

You could change your buttons after the entire UI has been created (assuming a GUI is not modified while open) – this way you only need one call site per frame/dialog:

public static class FocusHelper {
    public static void alterButtons(Component container) {
        if (component instanceof Container) {
            Component[] children = ((Container) component).getComponents();
            for (Component child : children) {
                alterButtons(child);
            }
        } else if (component instanceof JButton) {
            ((JButton) component).setRequestFocusEnabled(true);
        }
    }
}

The helper method just scans the entire component hierarchy for buttons and calls setRequestFocusEnabled() for each JButton (you may want to check for other component type(s) like AbstractButton, depending on what you want to achieve). You would just call the method from wherever the GUI is created and pass the top level container (JFrame, JDialog or any other Container component).