title: How does Flutter handle orientation change
body: <p>Is orientation change handling is as simple as widget's build is rerun with the updated dimensions in Flutter?</p>
  
  <p>I ask because in Android, the whole Activity is rebuilt, which is why all the information is sent via intents. </p>
  
  <p>Any gotchas to keep in mind while designing widgets so they will handle orientation changes or other changes that result in UI to change?</p>