--- title: TabSheet order: 9 layout: page --- [[layout.tabsheet]] = [classname]#TabSheet# ifdef::web[] [.sampler] image:{live-demo-image}[alt="Live Demo", link="http://demo.vaadin.com/sampler/#ui/structure/tab-sheet"] endif::web[] The [classname]#TabSheet# is a multicomponent container that allows switching between the components with "tabs". The tabs are organized as a tab bar at the top of the tab sheet. Clicking on a tab opens its contained component in the main display area of the layout. If there are more tabs than fit in the tab bar, navigation buttons will appear. [[figure.tabsheet.example1]] .A Simple TabSheet Layout image::img/tabsheet-example1.png[width=50%, scaledwidth=70%] [[layout.tabsheet.adding]] == Adding Tabs You add new tabs to a tab sheet with the [methodname]#addTab()# method. The simple version of the method takes as its parameter the root component of the tab. You can use the root component to retrieve its corresponding [classname]#Tab# object. Typically, you put a layout component as the root component. You can also give the caption and the icon as parameters for the [methodname]#addTab()# method. The following example demonstrates the creation of a simple tab sheet, where each tab shows a different [classname]#Label# component. The tabs have an icon, which are (in this example) loaded as Java class loader resources from the application. [source, java] ---- TabSheet tabsheet = new TabSheet(); layout.addComponent(tabsheet); // Create the first tab VerticalLayout tab1 = new VerticalLayout(); tab1.addComponent(new Embedded(null, new ThemeResource("img/planets/Mercury.jpg"))); tabsheet.addTab(tab1, "Mercury", new ThemeResource("img/planets/Mercury_symbol.png")); // This tab gets its caption from the component caption VerticalLayout tab2 = new VerticalLayout(); tab2.addComponent(new Embedded(null, new ThemeResource("img/planets/Venus.jpg"))); tab2.setCaption("Venus"); tabsheet.addTab(tab2).setIcon( new ThemeResource("img/planets/Venus_symbol.png")); ... ---- [[layout.tabsheet.tab]] == Tab Objects Each tab in a tab sheet is represented as a [classname]#Tab# object, which manages the tab caption, icon, and attributes such as hidden and visible. You can set the caption with [methodname]#setCaption()# and the icon with [methodname]#setIcon()#. If the component added with [methodname]#addTab()# has a caption or icon, it is used as the default for the [classname]#Tab# object. However, changing the attributes of the root component later does not affect the tab, but you must make the setting through the [classname]#Tab# object. The [methodname]#addTab()# returns the new [classname]#Tab# object, so you can easily set an attribute using the reference. [source, java] ---- // Set an attribute using the returned reference tabsheet.addTab(myTab).setCaption("My Tab"); ---- [[layout.tabsheet.tab.disabling]] === Disabling and Hiding Tabs A tab can be disabled by setting [methodname]#setEnabled(false)# for the [classname]#Tab# object, thereby disallowing selecting it. A tab can be made invisible by setting [methodname]#setVisible(false)# for the [classname]#Tab# object. The [methodname]#hideTabs()# method allows hiding the tab bar entirely. This can be useful in tabbed document interfaces (TDI) when there is only one tab. ifdef::web[] [[figure.tabsheet.example2]] .A TabSheet with Hidden and Disabled Tabs image::img/tabsheet-example2.png[width=50%, scaledwidth=70%] endif::web[] [[layout.tabsheet.events]] == Tab Change Events Clicking on a tab selects it. This fires a [classname]#TabSheet.SelectedTabChangeEvent#, which you can handle by implementing the [classname]#TabSheet.SelectedTabChangeListener# interface. You can access the tabsheet of the event with [methodname]#getTabSheet()#, and find the new selected tab with [methodname]#getSelectedTab()#. You can programmatically select a tab with [methodname]#setSelectedTab()#, which also fires the [classname]#SelectedTabChangeEvent# (beware of recursive events). Reselecting the currently selected tab does not fire the event. Notice that when the first tab is added, it is selected and the change event is fired, so if you want to catch that, you need to add your listener before adding any tabs. ifdef::web[] [[layout.tabsheet.events.dynamic]] === Creating Tab Content Dynamically In the following example, we create the tabs as empty content layouts, and add the tab content dynamically when a tab is selected: [source, java] ---- TabSheet tabsheet = new TabSheet(); // Create tab content dynamically when tab is selected tabsheet.addSelectedTabChangeListener( new TabSheet.SelectedTabChangeListener() { public void selectedTabChange(SelectedTabChangeEvent event) { // Find the tabsheet TabSheet tabsheet = event.getTabSheet(); // Find the tab (here we know it's a layout) Layout tab = (Layout) tabsheet.getSelectedTab(); // Get the tab caption from the tab object String caption = tabsheet.getTab(tab).getCaption(); // Fill the tab content tab.removeAllComponents(); tab.addComponent(new Image(null, new ThemeResource("img/planets/"+caption+".jpg"))); } }); // Have some tabs String[] tabs = {"Mercury", "Venus", "Earth", "Mars"}; for (String caption: tabs) tabsheet.addTab(new VerticalLayout(), caption, new ThemeResource("img/planets/"+caption+"_symbol.png")); ---- endif::web[] [[layout.tabsheet.closing]] == Enabling and Handling Closing Tabs You can enable a close button for individual tabs with the [literal]#++closable++# property in the [classname]#TabSheet.Tab# objects. [source, java] ---- // Enable closing the tab tabsheet.getTab(tabComponent).setClosable(true); ---- [[figure.layout.tabsheet.closing]] .TabSheet with Closable Tabs image::img/tabsheet-tabclose.png[width=50%, scaledwidth=70%] [[layout.tabsheet.closing.handling]] === Handling Tab Close Events You can handle closing tabs by implementing a custom [classname]#TabSheet.CloseHandler#. The default implementation simply calls [methodname]#removeTab()# for the tab to be closed, but you can prevent the close by not calling it. This allows, for example, opening a dialog window to confirm the close. [source, java] ---- tabsheet.setCloseHandler(new CloseHandler() { @Override public void onTabClose(TabSheet tabsheet, Component tabContent) { Tab tab = tabsheet.getTab(tabContent); Notification.show("Closing " + tab.getCaption()); // We need to close it explicitly in the handler tabsheet.removeTab(tab); } }); ---- ifdef::web[] [[layout.tabsheet.css]] == CSS Style Rules [source, css] ---- .v-tabsheet {} .v-tabsheet-tabs {} .v-tabsheet-content {} .v-tabsheet-deco {} .v-tabsheet-tabcontainer {} .v-tabsheet-tabsheetpanel {} .v-tabsheet-hidetabs {} .v-tabsheet-scroller {} .v-tabsheet-scrollerPrev {} .v-tabsheet-scrollerNext {} .v-tabsheet-scrollerPrev-disabled{} .v-tabsheet-scrollerNext-disabled{} .v-tabsheet-tabitem {} .v-tabsheet-tabitem-selected {} .v-tabsheet-tabitemcell {} .v-tabsheet-tabitemcell-first {} .v-tabsheet-tabs td {} .v-tabsheet-spacertd {} ---- The entire tabsheet has the [literal]#++v-tabsheet++# style. A tabsheet consists of three main parts: the tabs on the top, the main content pane, and decorations around the tabsheet. The tabs area at the top can be styled with [literal]#++v-tabsheet-tabs++#, [literal]#++v-tabsheet-tabcontainer++# and [literal]#++v-tabsheet-tabitem*++#. The style [literal]#++v-tabsheet-spacertd++# is used for any empty space after the tabs. If the tabsheet has too little space to show all tabs, scroller buttons enable browsing the full tab list. These use the styles [literal]#++v-tabsheet-scroller*++#. The content area where the tab contents are shown can be styled with [literal]#++v-tabsheet-content++#, and the surrounding decoration with [literal]#++v-tabsheet-deco++#. endif::web[]