Java tutorial
/* * See the NOTICE file distributed with this work for additional * information regarding copyright ownership. * * This is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * This software 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */ package org.xwiki.gwt.user.client; import com.google.gwt.event.logical.shared.BeforeSelectionEvent; import com.google.gwt.event.logical.shared.BeforeSelectionHandler; import com.google.gwt.event.logical.shared.SelectionEvent; import com.google.gwt.event.logical.shared.SelectionHandler; import com.google.gwt.user.client.ui.TabPanel; import com.google.gwt.user.client.ui.Widget; /** * Notifies {@link Selectable} tabs within a {@link TabPanel} when they are selected. * * @version $Id: 162b2d09a819493dd27f28901d1050192deba317 $ */ public class TabPanelSelector implements BeforeSelectionHandler<Integer>, SelectionHandler<Integer> { @Override public void onBeforeSelection(BeforeSelectionEvent<Integer> event) { if (!event.isCanceled()) { TabPanel tabPanel = (TabPanel) event.getSource(); int selectedTabIndex = tabPanel.getTabBar().getSelectedTab(); // Check if there is a selected tab and the tab to be selected is not the same. if (selectedTabIndex >= 0 && selectedTabIndex != event.getItem()) { Widget selectedTab = tabPanel.getDeckPanel().getWidget(selectedTabIndex); if (selectedTab instanceof Selectable && ((Selectable) selectedTab).isSelected()) { // Notify the tab before it is hidden. ((Selectable) selectedTab).setSelected(false); } } } } @Override public void onSelection(SelectionEvent<Integer> event) { TabPanel tabPanel = (TabPanel) event.getSource(); // Check if a tab was selected. if (event.getSelectedItem() >= 0) { Widget selectedTab = tabPanel.getDeckPanel().getWidget(event.getSelectedItem()); if (selectedTab instanceof Selectable && !((Selectable) selectedTab).isSelected()) { // Notify the tab after it is shown. ((Selectable) selectedTab).setSelected(true); } } } }