title: How to display loading widget until the main widget is loaded in flutter?
body: <p>I have a widget with a lot of contents like image, text and more, which make it heavy widget in flutter app, But when the app is navigated to the widget having the complex widget the app faces the jank since the widget is too large to load at an instant,</p>
  <p>I want to show simple lite loading widget until the original widget is loaded thus removing the jank from the app and enable lazy loading of the widget,</p>
  <p>How to achieve this in flutter?</p>
  <p><strong>EDIT</strong>:-
  To make it clear, I am not loading any data from the Internet, and this is not causing the delay. For Loading the data from Internet we have <code>FutureBuilder</code>. Here my widget is itself heavy such that it takes some time to load.</p>
  <p>How to display loading Widget while the main widget is being loaded.</p>