Flutter Opening the keyboard trigger my Navigator.push() callback - flutter

Question

In my app, I scan a barcode on the first page and call a second page when a valid barcode is scanned. On my second page, I have to edit some TextFields. I close the camera before calling the navigator and start it again when we close the second page using the .then() of the method Navigator.of(context).push().
The problem is as follows: when I click on a textfield, the keyboard appear and the .then() mentioned above is triggered. How do I do to not call it only when I'm back from the second page ?
if(result != null){
Navigator.push(scanned.context, MaterialPageRoute(builder: (BuildContext context) {
return InventoryItemSetQuantities(product: result, inventoryBloc: this, qrViewController: scanned.qrViewController);
})).then((value) => scanned.qrViewController.resumeCamera());
}

Answer 1

[EDIT]
Ok sorry, you needed to open the barcode scanner when the page popped, after you have filled out your textfield. In this case the easiest thing to do, is open the barcode scanner when the second page has been disposed (after popping). So do this:
#override
void dispose() {
super.dispose();
scanned.qrViewController.resumeCamera()
}
Make sure though to have a reference to the barcode scanner. You might have to pass into the second page as a constructor, thena ccess the reference to the scanner via the widget object, like so:
#override
void dispose() {
super.dispose();
widget.scanned.qrViewController.resumeCamera() //**scanned** is the passed barcode scanner from the first page
}
And in the original code make sure to remove the barcode scanner after then() callback. Do this:
if(result != null){
Navigator.push(scanned.context, MaterialPageRoute(builder: (BuildContext context) {
return InventoryItemSetQuantities(product: result, inventoryBloc: this, qrViewController: scanned.qrViewController);
}));
}