Installs a global hotkey in Vaadin. Then, when triggered, it would iterate through the component tree and some buttons. Nice example of rarely used operations/hacks :)

vaadin hotkey + iterate over components.java

    public void installHotkey() {
        LOG.info("Sprinkling magic all over");
        UI.getCurrent().addActionHandler(new Action.Handler() {
            @Override
            public Action[] getActions(Object target, Object sender) {
                return new Action[]{new ShortcutAction("Ctrl-Alt-F12", ShortcutAction.KeyCode.F12, new int[]{ShortcutAction.ModifierKey.ALT, ShortcutAction.ModifierKey.CTRL})};
            }

            @Override
            public void handleAction(Action action, Object sender, Object target) {
                final Iterator iterator = IteratorUtils.objectGraphIterator(UI.getCurrent().getContent(), new Transformer() {
                    @Override
                    public Object transform(Object input) {
                        if (input instanceof Iterable) {
                            return ((Iterable) input).iterator();
                        } else {
                            return input;
                        }
                    }
                });

                while (iterator.hasNext()) {
                    Object next = iterator.next();
                    if (next instanceof Button) {
                        Button button = (Button) next;
                        if (button.getCaption().endsWith(" MenuAction")) {
                            button.setEnabled(true);
                        }
                    }
                }
            }
        });