Java tutorial
/* * Copyright 2008 Google Inc. * * 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 cc.alcina.framework.gwt.client.widget; import java.util.Iterator; 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.HasSelectionHandlers; 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.FlowPanel; import com.google.gwt.user.client.ui.HasAnimation; import com.google.gwt.user.client.ui.HasWidgets; import com.google.gwt.user.client.ui.IndexedPanel; import com.google.gwt.user.client.ui.SimplePanel; import com.google.gwt.user.client.ui.SourcesTabEvents; import com.google.gwt.user.client.ui.TabListener; import com.google.gwt.user.client.ui.TabListenerCollection; import com.google.gwt.user.client.ui.UIObject; import com.google.gwt.user.client.ui.Widget; import cc.alcina.framework.gwt.client.widget.layout.HasLayoutInfo; /** * * Keep in sync with GWT - TabPanel */ @SuppressWarnings("deprecation") public class CustomisableTabPanel extends Composite implements TabListener, SourcesTabEvents, HasWidgets, HasAnimation, IndexedPanel, HasLayoutInfo, HasBeforeSelectionHandlers<Integer>, HasSelectionHandlers<Integer>, BeforeSelectionHandler<Integer>, SelectionHandler<Integer> { private UnmodifiableTabBar tabBar = new UnmodifiableTabBar(); private TabbedDeckPanel deck = new TabbedDeckPanel(tabBar); private TabListenerCollection tabListeners; private FlowPanel panel; /** * Creates an empty tab panel. */ public CustomisableTabPanel() { panel = new FlowPanel(); panel.add(tabBar); panel.add(deck); // panel.setCellHeight(deck, "100%"); // tabBar.setWidth("100%"); tabBar.addBeforeSelectionHandler(this); tabBar.addSelectionHandler(this); initWidget(panel); setStyleName("gwt-TabPanel"); deck.setStyleName("gwt-TabPanelBottom"); // Add a11y role "tabpanel" Accessibility.setRole(deck.getElement(), Accessibility.ROLE_TABPANEL); } public void add(Widget w) { throw new UnsupportedOperationException("A tabText parameter must be specified with add()."); } /** * 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) { insert(w, tabText, getWidgetCount()); } /** * 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 * TabPanel, 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()); } public HandlerRegistration addBeforeSelectionHandler(BeforeSelectionHandler<Integer> handler) { return addHandler(handler, BeforeSelectionEvent.getType()); } public HandlerRegistration addSelectionHandler(SelectionHandler<Integer> handler) { return addHandler(handler, SelectionEvent.getType()); } public void addTabListener(TabListener listener) { if (tabListeners == null) { tabListeners = new TabListenerCollection(); } tabListeners.add(listener); } public void allTabsAdded() { tabBar.allTabsAdded(); } public void clear() { while (getWidgetCount() > 0) { remove(getWidget(0)); } } /** * Gets the deck panel within this tab panel. Adding or removing Widgets * from the DeckPanel is not supported and will throw * UnsupportedOperationExceptions. * * @return the deck panel */ public DeckPanel getDeckPanel() { return deck; } public LayoutInfo getLayoutInfo() { return new LayoutInfo() { @Override public Iterator<Widget> getLayoutWidgets() { return panel.iterator(); } }; } /** * Gets the tab bar within this tab panel. Adding or removing tabs from from * the TabBar is not supported and will throw * UnsupportedOperationExceptions. * * @return the tab bar */ public FlowTabBar getTabBar() { return tabBar; } public Widget getWidget(int index) { return deck.getWidget(index); } public int getWidgetCount() { return deck.getWidgetCount(); } public int getWidgetIndex(Widget widget) { return deck.getWidgetIndex(widget); } /** * 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); } /** * 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 beforeIndex * the index before which it will be inserted */ public void insert(Widget widget, String tabText, int beforeIndex) { insert(widget, tabText, false, 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 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); } public boolean isAnimationEnabled() { return deck.isAnimationEnabled(); } public Iterator<Widget> iterator() { // The Iterator returned by DeckPanel supports removal and will invoke // TabbedDeckPanel.remove(), which is an active function. return deck.iterator(); } public void onBeforeSelection(BeforeSelectionEvent<Integer> event) { fireEvent(event); } /** * @deprecated Use {@link BeforeSelectionHandler#onBeforeSelection} instead */ @Deprecated public boolean onBeforeTabSelected(SourcesTabEvents sender, int tabIndex) { BeforeSelectionEvent<Integer> event = BeforeSelectionEvent.fire(this, tabIndex); return event == null || !event.isCanceled(); } public void onSelection(SelectionEvent<Integer> event) { int tabIndex = event.getSelectedItem(); deck.showWidget(tabIndex); fireEvent(event); } /** * @deprecated Use {@link SelectionHandler#onSelection} instead */ @Deprecated public void onTabSelected(SourcesTabEvents sender, int tabIndex) { deck.showWidget(tabIndex); SelectionEvent.fire(this, tabIndex); } 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); } public void removeTabListener(TabListener listener) { if (tabListeners != null) { tabListeners.remove(listener); } } /** * 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); } public void setChildWidths(String width) { tabBar.setWidth(width); deck.setWidth(width); } @Override public void setWidth(String width) { super.setWidth(width); } /** * Create a {@link SimplePanel} that will wrap the contents in a tab. * Subclasses can use this method to wrap tabs in decorator panels. * * @return a {@link SimplePanel} to wrap the tab contents, or null to leave * tabs unwrapped */ protected SimplePanel createTabTextWrapper() { return null; } /** * <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"); } public static class ResizableDeckPanel extends DeckPanel implements HasLayoutInfo { public LayoutInfo getLayoutInfo() { return new LayoutInfo() { public Iterator<Widget> getLayoutWidgets() { return ResizableDeckPanel.this.iterator(); } public boolean to100percentOfAvailableHeight() { return true; } }; } } /** * This extension of DeckPanel overrides the public mutator methods to * prevent external callers from adding to the state of the DeckPanel. * <p> * Removal of Widgets is supported so that WidgetCollection.WidgetIterator * operates as expected. * </p> * <p> * 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 ResizableDeckPanel { private UnmodifiableTabBar tabBar; public TabbedDeckPanel(UnmodifiableTabBar tabBar) { this.tabBar = tabBar; } @Override public void add(Widget w) { throw new UnsupportedOperationException("Use TabPanel.add() to alter the DeckPanel"); } @Override public void clear() { throw new UnsupportedOperationException("Use TabPanel.clear() to alter the DeckPanel"); } @Override public void insert(Widget w, int beforeIndex) { throw new UnsupportedOperationException("Use TabPanel.insert() to alter the DeckPanel"); } @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.removeTabProtected(idx); return super.remove(w); } return false; } 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.insertTabProtected(tabText, asHTML, beforeIndex); super.insert(w, beforeIndex); } protected void insertProtected(Widget w, Widget tabWidget, 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.insertTabProtected(tabWidget, beforeIndex); super.insert(w, beforeIndex); } } /** * This extension of TabPanel overrides the public mutator methods to * prevent external callers from modifying the state of the TabBar. */ private class UnmodifiableTabBar extends FlowTabBar { public UnmodifiableTabBar() { super(); } @Override public void insertTab(String text, boolean asHTML, int beforeIndex) { throw new UnsupportedOperationException("Use TabPanel.insert() to alter the TabBar"); } @Override public void insertTab(Widget widget, int beforeIndex) { throw new UnsupportedOperationException("Use TabPanel.insert() to alter the TabBar"); } public void insertTabProtected(String text, boolean asHTML, int beforeIndex) { super.insertTab(text, asHTML, beforeIndex); } public void insertTabProtected(Widget widget, int beforeIndex) { super.insertTab(widget, beforeIndex); } @Override public void removeTab(int index) { // It's possible for removeTab() to function correctly, but it's // preferable to have only TabbedDeckPanel.remove() be operable, // especially since TabBar does not export an Iterator over its // values. throw new UnsupportedOperationException("Use TabPanel.remove() to alter the TabBar"); } public void removeTabProtected(int index) { super.removeTab(index); } @Override protected SimplePanel createTabTextWrapper() { return CustomisableTabPanel.this.createTabTextWrapper(); } } }