title: how to place a cliackable overlay on top of another activity in android?
body: <p>i need to place a view on top of another activity which should have clickable buttons etc. the underlying activity itself MUST NOT be stopped/paused or else.</p>
  
  <p>to be more specific: i want to display some kind of a note when i receive a call. this note should be displayed on top of the incoming-call-activity without disrupting the activity itself or hindering the user from interacting with it...</p>
  
  <p>how do i do this?</p>