title: Showing progress bar while loading Firebase database
body: <p>I am using Firebase realtime database in my app. I have listView and adapter that each view of the adapter load one item from the Firebase database. But it takes few seconds to load all of the data (each item has image and name). So I want to show progress bar or something to show to the user, but I don't know where to put it.</p>
  
  <p>I thought about using asynctask or something, but the problem is that I don't really know where the data are loaded. I am attaching child event listener to Firebase database reference object, so any time a new child is added, the adapter will be updated, but I don't know how to know that all of the children had finished to load.</p>
  
  <p>Hope you understand me and help me.</p>