title: ActionBar navigation tab item that starts an activity?
body: <p>I have an activity that uses ActionBarSherlock to show an action bar with navigation tabs. I need one of those tabs to open another activity (taking over the whole screen) when it is tapped. I built a custom TabListener to achieve this, but it fires when the tab contents are initially rendered, not just when it's manually selected.</p>
  
  <p>I can't see a way to catch a traditional onClick event, so I assume I need to handle this in the TabListener and somehow distinguish the initial selection from a later manual selection, but how? I could use a counter each time the tab is selected and only start the secondary activity if the counter is above zero, but that looks like an ugly hack. I was hoping there was a way to handle a "click" as opposed to a "selection" as the latter includes both the initial display of the views, as well as later manual clicks.</p>
  
  <p>I attach the listener to the action bar navigation tab like this:</p>
  
  <pre><code>tab.setTabListener(new TabDiseaseSelectorListener(this));
  </code></pre>
  
  <p>And then the listener looks like this:</p>
  
  <pre><code>    public class TabDiseaseSelectorListener implements ActionBar.TabListener {
      private final Activity mActivity;
  
      public TabDiseaseSelectorListener(Activity activity) {
          mActivity = activity;
      }
  
      public void onTabSelected(ActionBar.Tab tab, FragmentTransaction unused) {
          Intent intent = new Intent();
          intent.setAction(Intent.ACTION_VIEW);
          intent.setClass(mActivity, DiseaseSelector.class);
          startActivity(intent);
      }
  
      public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction unused) {
      }
  
      public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {
      }
  }
  </code></pre>
  
  <p>I tried using onTabReselected() but that only fires if the tab is already selected and the user taps it again.</p>