title: TransitionManager progress manually
body: <p>I am currenlty exploring a somewhat complex UI similar to the <code>BottomSheetBehaviour</code> used in Google Maps, where one can animate an item from a collapsed state into an expanded state. The transition between those 2 states are Scene Transitions using the <code>TransitionManager</code> framework and work rather nicely.</p>
  
  <p>I am now exploring a way to <strong>drag</strong> the expanded view again into the collapsed state and vice versa, but I did not find any obvious way to manually progress a scene transition.</p>
  
  <p>What I would need would be something like: <code>Transition.setAnimatedFraction(0.5f)</code>
  based on the percentage the user has dragged between the 2 states.</p>
  
  <p><a href="https://i.stack.imgur.com/r559e.png" rel="noreferrer"><img src="https://i.stack.imgur.com/r559e.png" alt="A drag transition between those 2 states"></a></p>
  
  <p>Does anyone here have any idea on how to achieve that?</p>