Autoscroll when keyboard open on purchase screen

lib/base/base_state.dart

@@ -318,84 +318,3 @@ abstract class BaseState<T extends StatefulWidget> extends State<T> {
     return new Container(margin: margin, height: buttonHeight, child: new Row(children: <Widget>[new Expanded(child: widget)]));
   }
 }
-
-class EnsureVisibleWhenFocused extends StatefulWidget {
-  const EnsureVisibleWhenFocused({
-    Key key,
-    @required this.child,
-    @required this.focusNode,
-    this.curve: Curves.ease,
-    this.duration: const Duration(milliseconds: 100),
-  }) : super(key: key);
-
-  /// The node we will monitor to determine if the child is focused
-  final FocusNode focusNode;
-
-  /// The child widget that we are wrapping
-  final Widget child;
-
-  /// The curve we will use to scroll ourselves into view.
-  ///
-  /// Defaults to Curves.ease.
-  final Curve curve;
-
-  /// The duration we will use to scroll ourselves into view
-  ///
-  /// Defaults to 100 milliseconds.
-  final Duration duration;
-
-  EnsureVisibleWhenFocusedState createState() => new EnsureVisibleWhenFocusedState();
-}
-
-class EnsureVisibleWhenFocusedState extends State<EnsureVisibleWhenFocused> {
-  @override
-  void initState() {
-    super.initState();
-    widget.focusNode.addListener(_ensureVisible);
-  }
-
-  @override
-  void dispose() {
-    super.dispose();
-    widget.focusNode.removeListener(_ensureVisible);
-  }
-
-  Future<Null> _ensureVisible() async {
-    // Wait for the keyboard to come into view
-    // TODO: position doesn't seem to notify listeners when metrics change,
-    // perhaps a NotificationListener around the scrollable could avoid
-    // the need insert a delay here.
-    await new Future.delayed(const Duration(milliseconds: 100));
-
-    if (!widget.focusNode.hasFocus)
-      return;
-
-    final RenderObject object = context.findRenderObject();
-    final RenderAbstractViewport viewport = RenderAbstractViewport.of(object);
-    assert(viewport != null);
-
-    ScrollableState scrollableState = Scrollable.of(context);
-    assert(scrollableState != null);
-
-    ScrollPosition position = scrollableState.position;
-    double alignment;
-    if (position.pixels > viewport.getOffsetToReveal(object, 0.0)) {
-      // Move down to the top of the viewport
-      alignment = 0.0;
-    } else if (position.pixels < viewport.getOffsetToReveal(object, 1.0)) {
-      // Move up to the bottom of the viewport
-      alignment = 1.0;
-    } else {
-      // No scrolling is necessary to reveal the child
-      return;
-    }
-    position.ensureVisible(
-      object,
-      alignment: alignment,
-      duration: widget.duration,
-      curve: widget.curve,
-    );
-  }
-
-  Widget build(BuildContext context) => widget.child;
-}