问在primefaces <p:tabView>`中停止TabChange

EN

<p:tabView  id="customerTab"
            orientation="left"
            dynamic="false"
            cache="false" 
            widgetVar="detailsTab" 
            activeIndex="#{myBean.activTab}"
            >

     <p:ajax  event="tabChange" listener="#{myBean.onTabChange}" update="customerTabv" />


        <p:tab  tab1> </p:tab>
        <p:tab  tab2> </p:tab>

public void onTabChange(
        TabChangeEvent event) {
    if (Tab.isInEditMode()) {

        FacesMessage msg = new FacesMessage("Tab Changed", "Active Tab: " + event.getTab().getId()
                + "You can not change the tab when you are in Edit mode!");
        FacesContext.getCurrentInstance().addMessage(null, msg);

        this.messagesTab.setActiveIndex(0);
        //          //          RequestContext.getCurrentInstance().execute("tabWidget.select(0)");
        activTab = 0;

        FacesContext.getCurrentInstance().setProcessingEvents(false);


    } else {
                TabView tabView = (TabView) event.getComponent();
                int activeIndex = tabView.getChildren().indexOf(event.getTab());
                this.messagesTab.setActiveIndex(activeIndex);
                activTab = activeIndex;
    }

}