title: Accessing MainWindow from another window
body: <p>I have created a new Window that opens up from the MainWindow. Upon clicking a button from this Window, the Window should close and at the same time trigger some event in MainWindow.</p>
  
  <p>I thought this would be easy to implement but I don't know how to access MainWindow methods &amp; fields from another Window...</p>
  
  <p>Any help would be appreciated. Thanks! :)</p>