title: Flutter disable tab bar items
body: <p>I want to be able to programmatically disable/enable tab bar items in Flutter and was wondering how to go about doing that? </p>
  
  <p>In IOS for example, it would be along the lines of <code>tabBarItem1.isEnabled = false</code>.</p>
  
  <p>I want to disable user interaction with the tab bar until they go through a process first for example pressing a button.</p>
  
  <p>Any help/pointers would be much appreciated.</p>