Adding a Flutter View to an Android app

Add Flutter to existing app

Adding Flutter to Android

Integrate via FlutterView

A sample

General approach

APIs to implement

Warning:
  Integrating via a FlutterView
  is advanced usage and requires manually creating custom, application specific
  bindings.

Integrating via a FlutterView
requires a bit more work than via FlutterActivity and FlutterFragment previously
described.

Fundamentally, the Flutter framework on the Dart side requires access to various
activity-level events and lifecycles to function. Since the FlutterView (which
is an android.view.View)
can be added to any activity which is owned by the developer’s application
and since the FlutterView doesn’t have access to activity level events, the
developer must bridge those connections manually to the FlutterEngine.