outline.dart

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        fit: StackFit.expand,
        children: <Widget>[
          _camera == null
              ? Container(
            color: Colors.black,
          )
              : Container(
              height: MediaQuery
                  .of(context)
                  .size
                  .height - 150,
              child: CameraPreview(_camera)),
          _buildResults(_textScanResults),
        ],
      ),
    );
  }
  
    Widget _buildResults(VisionText scanResults) {
    CustomPainter painter;
    if (scanResults != null) {
      final Size imageSize = Size(
        _camera.value.previewSize.height - 100,
        _camera.value.previewSize.width,
      );
      painter = TextDetectorPainter(imageSize, scanResults);
      getWords(scanResults);

      return CustomPaint(
        painter: painter,
      );
    } else {
      return Container();
    }
  }