void showHandles()

Shows the handles by inserting them into the context's overlay.

Source 

void showHandles() {
  assert(_handles == null);
  _handles = <OverlayEntry>[
    new OverlayEntry(builder: (BuildContext c) => _buildHandle(c, _TextSelectionHandlePosition.start)),
    new OverlayEntry(builder: (BuildContext c) => _buildHandle(c, _TextSelectionHandlePosition.end)),
  ];
  Overlay.of(context, debugRequiredFor: debugRequiredFor).insertAll(_handles);
  _handleController.forward(from: 0.0);
}