title: Hide TabBar Navigation based on currently selected TabBar Item in Ex-Navigation
body: <p>I'm interesting in hiding the tab bar navigator based on the currently selected tab bar item. Is there anyway that I can subscribe to the change tab event? This is my current tab navigation setup:</p>
  
  <p><code>&lt;TabNavigation
          tabBarHeight={48}
          tabBarStyle={this._getTabBarStyle(this.props)}
          sceneStyle={this._getSceneStyle(this.props)}
          id='main'
          navigatorUID='main'
          initialTab='catalog'
          onRegisterNavigatorContext={() =&gt; {
            console.log(this)
          }}
        &gt;
          &lt;TabItem
            id='catalog'
            renderIcon={isSelected =&gt; {
              if (isSelected) {
                return &lt;TabButton type='selectedCatalog' /&gt;
              } else {
                return &lt;TabButton type='catalog' /&gt;
              }
            }} &gt;
            &lt;StackNavigation initialRoute={Router.getRoute('catalog')} /&gt;
          &lt;/TabItem&gt;
          &lt;TabItem
            id='notification'
            renderIcon={isSelected =&gt; {
              if (isSelected) {
                return &lt;TabButton type='selectedNotifications' /&gt;
              } else {
                return (
                  &lt;View&gt;
                    &lt;TabButton type='notifications' /&gt;
                  &lt;/View&gt;
                )
              }
            }} &gt;
            &lt;StackNavigation initialRoute={Router.getRoute('notification')} /&gt;
          &lt;/TabItem&gt;
          &lt;TabItem
            id='redeem'
            renderIcon={isSelected =&gt; {
              if (isSelected) {
                return &lt;TabButton type='selectedRedeem' /&gt;
              } else {
                return &lt;TabButton type='redeem' /&gt;
              }
            }} &gt;
            &lt;StackNavigation initialRoute={Router.getRoute('redeem')} /&gt;
          &lt;/TabItem&gt;
        &lt;/TabNavigation&gt;</code></p>