TabSheet

<tabSheet width="300px">
    <tab id="tab_1"
         caption="Tab number 1"
         margin="true"
         spacing="true">
        <label value="Label 1"/>
        <textField inputPrompt="TextField 1"/>
        <button caption="Button 1"/>
    </tab>
    <tab id="tab_2"
         caption="Tab number 2"
         margin="true"
         spacing="true">
        <label value="Label 2"/>
        <textField inputPrompt="TextField 2"/>
        <button caption="Button 2"/>
    </tab>
</tabSheet>

<tabSheet id="tabSheet"
          width="200"
          height="100">
    <tab id="tab1"
         caption="Tab 1"
         margin="true">
        <label id="label1"
               value="Label 1"/>
    </tab>
    <tab id="tab2"
         caption="Tab 2"
         margin="true"
         lazy="true">
        <label id="label2"
               value="Label 2"/>
    </tab>
</tabSheet>

<label id="info" align="MIDDLE_LEFT"/>

@Autowired
private Label<String> info;
@Autowired
private TabSheet tabSheet;

@Subscribe
public void onInit(InitEvent event) {
    checkComponents();
}

@Subscribe("tabSheet")
protected void onTabSheetSelectedTabChange(TabSheet.SelectedTabChangeEvent event) {
    if (event.getSelectedTab().getName().equals("tab2")) {
        checkComponents();
    }
}

private void checkComponents() {
    StringBuilder sb = new StringBuilder("Created components:\n");

    sb.append("label1 = ");
    Label<String> label1 = (Label<String>) tabSheet.getComponentNN("label1");
    sb.append(label1.getValue());

    try{
        Label<String> label2 = (Label<String>) tabSheet.getComponentNN("label2");
        sb.append(", label2 = ");
        sb.append(label2.getValue());
    } catch (IllegalArgumentException e){
        sb.append(", label2 was not found");
    }
    info.setValue(sb.toString());
}