title: How Can I Monitor Which Window Currently Has Keyboard Focus
body: <p>Is there a way to track which window currently has keyboard focus. I could handle WM_SETFOCUS for every window but I'm wondering if there's an alternative, simpler method (i.e. a single message handler somewhere).</p>
  
  <p>I could use OnIdle() in MFC and call GetFocus() but that seems a little hacky.</p>