private static void processInputEvent(InputEvent e) {
    final int usedKeyMask = InputEvent.ALT_DOWN_MASK |
                            InputEvent.META_DOWN_MASK |
                            InputEvent.CTRL_DOWN_MASK |
                            InputEvent.SHIFT_DOWN_MASK |
                            InputEvent.ALT_GRAPH_DOWN_MASK;
    final int oldLastModifiersEx = lastModifiersEx;
    lastModifiersEx = e.getModifiersEx() & usedKeyMask;
    final boolean areModifiersChanged = lastModifiersEx != oldLastModifiersEx;

    if (e instanceof MouseEvent && !areModifiersChanged) {
      // NOTE: to increase the stability of switching normal/alt layouts, we process changes of modifier mask even from mouse events
      return;
    }

    // check esc button
    if (Helpers.isPhisycalEsc()
        && e instanceof KeyEvent
        && e.getID() == KeyEvent.KEY_RELEASED
        && ((KeyEvent)e).getKeyCode() == KeyEvent.VK_ESCAPE
        && lastModifiersEx == 0
    ) {
      // find current (showing) component corresponding to an event window
      final Window windowOfEvent = getWindow(e.getComponent());
      if (windowOfEvent == null) {
        if (LOG_INPUT_PROCESSING) LOG.debug("INPUT: can't find window of component %s (during isPhisycalEsc processing)", e.getComponent());
        return;
      }

      final Stack s = ourStacks.get(windowOfEvent);
      if (s != null) {
        final @Nullable ComponentActions ca = s.getTopActions();
        if (ca != null && ca.getCurrent() != null && ca.getCurrent().isCrossEsc()) {
          s.pop();
        }
      }
    }

    if (LOG_INPUT_PROCESSING) {
      final Window windowOfEvent = getWindow(e.getComponent());
      final @Nullable ComponentActions componentActions = getShownActions(windowOfEvent);
      if (componentActions == null) {
        LOG.debug("INPUT: no touchbar actions are shown for window '%s', component '%s'", windowOfEvent, e.getComponent());
      }
      else {
        LOG.debug("INPUT: show actions of component %s, keymask=%d", componentActions.component.get(), lastModifiersEx);
      }
    }

    if (areModifiersChanged) {
      // change to alt for all registered components
      for (ComponentActions ca : ourComp2Actions.values()) {
        if (ca != null) {
          ca.setCurrent(lastModifiersEx);
        }
      }

      // NOTE: mask-change can be received from popup window, but we must update stack for popup and also at least for main-frame.
      // So update for all windows.
      for (Stack s : ourStacks.values()) {
        s.updateIfNecessary();
      }
    }
  }
private static void processInputEvent(InputEvent e)