title: How do I trigger an action/detect when a user swipes away from a ModalBottomSheet in a Flutter app?
body: <p>I have implemented a filter feature in my app, which opens up a modalBottomSheet with some filtering options when a user clicks on a particular button.</p>
  <p>I want to get data from my database based on the filters, right when the user clicks/swipes away from the modalBottomSheet.</p>
  <p>How do I detect that they've done this?
  Is there a better way to do this?</p>