title: Set navigation drawer under toolbar
body: <p>My question is simple.</p>
  
  <p>I created a navigation drawer activity. When the drawer is open it looks like this:
  <a href="https://i.stack.imgur.com/LZxCe.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LZxCe.jpg" alt="Navigation drawer covers the toolbar"></a></p>
  
  <p>I want the drawer to be under the toolbar, so I will see the "back arrow", like this:
  <a href="https://i.stack.imgur.com/R7VcD.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/R7VcD.jpg" alt="enter image description here"></a></p>
  
  <p>From other projects I've seen, I think it can be done by using "FrameLayout".
  The "nav_header" layout contains a FrameLayout which covers the whole screen but the toolbar. I just could not figure out how exactly to do this:</p>
  
  <p><a href="https://i.stack.imgur.com/1w3XP.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1w3XP.jpg" alt="As you can see, the FrameLayout does not cover the toolbar"></a></p>
  
  <p>P.S.
  How do I set the navigation drawer's width?
  I want it narrower...</p>