Java tutorial
package de.metas.procurement.webui.ui.view; import com.vaadin.addon.touchkit.ui.NavigationManager; import com.vaadin.navigator.View; import com.vaadin.navigator.ViewChangeListener.ViewChangeEvent; /* * #%L * de.metas.procurement.webui * %% * Copyright (C) 2016 metas GmbH * %% * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as * published by the Free Software Foundation, either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program. If not, see * <http://www.gnu.org/licenses/gpl-2.0.html>. * #L% */ @SuppressWarnings("serial") public class MainView extends NavigationManager implements View { private DailyReportingView dailyReportingView; public MainView() { super(); } @Override public void enter(ViewChangeEvent event) { if (dailyReportingView == null) { dailyReportingView = new DailyReportingView(); setCurrentComponent(dailyReportingView); } } }