@Override
    public void onPrepareSubMenu(final SubMenu subMenu) {
        subMenu.clear();
        if (callback == null) {
            return;
        }
        final List<CacheListApp> activeApps = CacheListApps.getActiveApps();
        for (int i = 0; i < activeApps.size(); i++) {
            final CacheListApp app = activeApps.get(i);
            subMenu.add(Menu.NONE, i, Menu.NONE, app.getName()).setOnMenuItemClickListener(item -> {
                callback.onListNavigationSelected(app);
                return true;
            });
        }
    }
Creates a new instance. ActionProvider classes should always implement a
constructor that takes a single Context parameter for inflating from menu XML.

@param context Context for accessing resources.
main/src/main/java/cgeo/geocaching/apps/cachelist/ListNavigationSelectionActionProvider.java