Add ability to scan once instead of multiple times

Great Work on this package! very helpful, thanks. I have this issue, I have this :

qrCodeCallback: (code) {
        var route = MaterialPageRoute(
          builder: (BuildContext context) => ProductDetails(
                productCode: code,
              ),
        );
        return Navigator.of(context).push(route);
      }

and it builds too many pages. Also, is there a specific example on how to work with the QrCameraState as the GlobalKey? a bit confused on that part.

[rmtmckenzie]

I’m eventually going to do a refactor to split the logic of the view and the controller, and when I do I’ll probably put in an option to stop after the first item.

But for now you’re probably better off just using a member variable and setting it to true once you’ve scanned the item, then ignoring it in the callback.

Note that you don’t have to do setState as you’re not changing anything that affects the build funciton.

i.e.

class QrScannerState extends State<QrScanner> {

  bool hasScanned = false;

  qrCodeCallback: (code) {
    if (hasScanned) return;
    hasScanned = true;
    ......
  }
}

And if you actually want to stop/start the camera using GlobalKey, this is how you’d do it. I haven’t included it in the example as it’s actually a pretty messy way of doing things and I’d like to replace it as soon as I get time.

class QrScannerState extends State<QrScanner> {
  GlobalKey<QrCameraState> qrCameraKey = GlobalKey();

  @override
  Widget build(BuildContext context) {
    return ....
      ...
      QrCamera(
        key: qrCameraKey,
        qrCodeCallback: (code) async {
          qrCameraKey.currentState.stop();
          ...
        }
      ...
  }
}

[HectorV12]

Appreciate the help, thanks again!