title: Navigation Drawer - Slowly animate menu items
body: <p>I've implemented a <code>DrawerLayout</code> with <a href="http://www.androidhive.info/2013/11/android-sliding-menu-using-navigation-drawer/" rel="nofollow">this</a> tutorial and everything works fine.</p>
  
  <pre><code>@Override
  public boolean onPrepareOptionsMenu(Menu menu) {
      // if nav drawer is opened, hide the action items
      boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
      menu.findItem(R.id.action_settings).setVisible(!drawerOpen);
      return super.onPrepareOptionsMenu(menu);
  }
  </code></pre>
  
  <p><code>onPrepareOptionsMenu</code> simply toggles the menu visibility in one shot. But I'd like to slowly animate the alpha value of my menu items as the drawer slides.</p>