Java tutorial
/* * Copyright 2011 cruxframework.org. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package org.cruxframework.crux.widgets.client.rollingtabs; import com.google.gwt.dom.client.Style.Overflow; import com.google.gwt.event.logical.shared.BeforeSelectionEvent; import com.google.gwt.event.logical.shared.BeforeSelectionHandler; import com.google.gwt.event.logical.shared.HasBeforeSelectionHandlers; import com.google.gwt.event.logical.shared.SelectionEvent; import com.google.gwt.event.logical.shared.SelectionHandler; import com.google.gwt.event.shared.HandlerRegistration; import com.google.gwt.user.client.ui.Accessibility; import com.google.gwt.user.client.ui.Composite; import com.google.gwt.user.client.ui.DeckPanel; import com.google.gwt.user.client.ui.HasAnimation; import com.google.gwt.user.client.ui.UIObject; import com.google.gwt.user.client.ui.VerticalPanel; import com.google.gwt.user.client.ui.Widget; /** * Modified version of GWT TabPanel that uses a CustomRollingPanel wrapping its TabBar. * * @author Thiago da Rosa de Bustamante - * */ public class RollingTabPanel extends Composite implements HasAnimation, HasBeforeSelectionHandlers<Integer> { private TabbedDeckPanel deck = null; private RollingTabBar tabBar = null; /** * Creates an empty tab panel. */ public RollingTabPanel() { tabBar = new RollingTabBar(); deck = new TabbedDeckPanel(tabBar); VerticalPanel panel = new VerticalPanel(); panel.add(tabBar); panel.add(deck); panel.setCellHeight(deck, "100%"); tabBar.setWidth("100%"); initWidget(panel); tabBar.addSelectionHandler(new SelectionHandler<Integer>() { public void onSelection(SelectionEvent<Integer> event) { deck.showWidget(event.getSelectedItem()); } }); tabBar.addBeforeSelectionHandler(new BeforeSelectionHandler<Integer>() { public void onBeforeSelection(BeforeSelectionEvent<Integer> event) { BeforeSelectionEvent<Integer> tabPanelEvent = BeforeSelectionEvent.fire(RollingTabPanel.this, event.getItem()); if (tabPanelEvent == null || tabPanelEvent.isCanceled()) { if (event != null) { event.cancel(); } } } }); setStyleName("crux-TabPanel"); deck.setStyleName("crux-TabPanelBottom"); deck.getElement().getStyle().setOverflow(Overflow.HIDDEN); // Add a11y role "TabPanel" Accessibility.setRole(deck.getElement(), Accessibility.ROLE_TABPANEL); } /** * Adds a widget to the tab panel. If the Widget is already attached to the * TabPanel, it will be moved to the right-most index. * * @param w the widget to be added * @param tabText the text to be shown on its tab */ public void add(Widget w, String tabText) { add(w, tabText, false); } /** * Adds a widget to the tab panel. If the Widget is already attached to the * TabPanel, it will be moved to the right-most index. * * @param w the widget to be added * @param tabText the text to be shown on its tab * @param asHTML <code>true</code> to treat the specified text as HTML */ public void add(Widget w, String tabText, boolean asHTML) { insert(w, tabText, asHTML, getWidgetCount()); } /** * Adds a widget to the tab panel. If the Widget is already attached to the * InternalTabPanel, it will be moved to the right-most index. * * @param w * the widget to be added * @param tabWidget * the widget to be shown in the tab */ public void add(Widget w, Widget tabWidget) { insert(w, tabWidget, getWidgetCount()); } /** * @see com.google.gwt.event.logical.shared.HasBeforeSelectionHandlers#addBeforeSelectionHandler(com.google.gwt.event.logical.shared.BeforeSelectionHandler) */ public HandlerRegistration addBeforeSelectionHandler(BeforeSelectionHandler<Integer> handler) { return addHandler(handler, BeforeSelectionEvent.getType()); } /** * */ public void clear() { while (getWidgetCount() > 0) { remove(getWidget(0)); } } public Widget getWidget(int index) { return deck.getWidget(index); } public int getWidgetCount() { return deck.getWidgetCount(); } public int getWidgetIndex(Widget widget) { return deck.getWidgetIndex(widget); } public RollingTabBar getTabBar() { return tabBar; } /** * Inserts a widget into the tab panel. If the Widget is already attached to * the InternalTabPanel, it will be moved to the requested index. * * @param widget * the widget to be inserted. * @param tabWidget * the widget to be shown on its tab. * @param beforeIndex * the index before which it will be inserted. */ public void insert(Widget widget, Widget tabWidget, int beforeIndex) { // Delegate updates to the TabBar to our DeckPanel implementation deck.insertProtected(widget, tabWidget, beforeIndex); } /** * Inserts a widget into the tab panel. If the Widget is already attached to * the TabPanel, it will be moved to the requested index. * * @param widget the widget to be inserted * @param tabText the text to be shown on its tab * @param asHTML <code>true</code> to treat the specified text as HTML * @param beforeIndex the index before which it will be inserted */ public void insert(Widget widget, String tabText, boolean asHTML, int beforeIndex) { // Delegate updates to the TabBar to our DeckPanel implementation deck.insertProtected(widget, tabText, asHTML, beforeIndex); } public boolean isAnimationEnabled() { return deck.isAnimationEnabled(); } public boolean remove(int index) { // Delegate updates to the TabBar to our DeckPanel implementation return deck.remove(index); } /** * Removes the given widget, and its associated tab. * * @param widget * the widget to be removed */ public boolean remove(Widget widget) { // Delegate updates to the TabBar to our DeckPanel implementation return deck.remove(widget); } /** * Programmatically selects the specified tab. * * @param index * the index of the tab to be selected */ public void selectTab(int index) { tabBar.selectTab(index); } public void setAnimationEnabled(boolean enable) { deck.setAnimationEnabled(enable); } /** * <b>Affected Elements:</b> * <ul> * <li>-bar = The tab bar.</li> * <li>-bar-tab# = The element containing the content of the tab itself.</li> * <li>-bar-tab-wrapper# = The cell containing the tab at the index.</li> * <li>-bottom = The panel beneath the tab bar.</li> * </ul> * * @see UIObject#onEnsureDebugId(String) */ @Override protected void onEnsureDebugId(String baseID) { super.onEnsureDebugId(baseID); tabBar.ensureDebugId(baseID + "-bar"); deck.ensureDebugId(baseID + "-bottom"); } /** * @return */ public int getSelectedTab() { return tabBar.getSelectedTab(); } /** * We ensure that the DeckPanel cannot become of of sync with its associated * TabBar by delegating all mutations to the TabBar to this implementation * of DeckPanel. * </p> */ private static class TabbedDeckPanel extends DeckPanel { private RollingTabBar tabBar; public TabbedDeckPanel(RollingTabBar tabBar) { this.tabBar = tabBar; } @Override public boolean remove(Widget w) { // Removal of items from the TabBar is delegated to the DeckPanel // to ensure consistency int idx = getWidgetIndex(w); if (idx != -1) { tabBar.removeTab(idx); return super.remove(w); } return false; } protected void insertProtected(Widget w, Widget tabWidget, int beforeIndex) { // Check to see if the InternalTabPanel already contains the Widget. // If so, // remove it and see if we need to shift the position to the left. int idx = getWidgetIndex(w); if (idx != -1) { remove(w); if (idx < beforeIndex) { beforeIndex--; } } tabBar.insertTab(tabWidget, beforeIndex); super.insert(w, beforeIndex); } protected void insertProtected(Widget w, String tabText, boolean asHTML, int beforeIndex) { // Check to see if the TabPanel already contains the Widget. If so, // remove it and see if we need to shift the position to the left. int idx = getWidgetIndex(w); if (idx != -1) { remove(w); if (idx < beforeIndex) { beforeIndex--; } } tabBar.insertTab(tabText, asHTML, beforeIndex); super.insert(w, beforeIndex); } } }