ZXingScannerView Android 6 Camera Permission

Question

I'm using ZXingScannerView as a qr-code reader in my Fragment
Now I'm having trouble to get the camera work right with the new Android 6 permissions.

Below API 23 everything works fine.

In my onCreateView method I check if camera permission is granted and otherwise ask for it. The dialog appears and I can grant the permission.

But the camera preview remains black until I change the orientation of my device.

Here's my code:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle state){

    mScannerView = new ZXingScannerView(getActivity());

    if (ActivityCompat.checkSelfPermission(getMainActivity(), Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
        requestPermissions(new String[]{Manifest.permission.CAMERA}, PERMISSION_REQUEST_CAMERA_SCAN_QR);
    } else {
        if(state != null) {
            mFlash = state.getBoolean(FLASH_STATE, false);
            mAutoFocus = state.getBoolean(AUTO_FOCUS_STATE, true);
            mSelectedIndices = state.getIntegerArrayList(SELECTED_FORMATS);
            mCameraId = state.getInt(CAMERA_ID, -1);
        } else {
            mFlash = false;
            mAutoFocus = true;
            mSelectedIndices = null;
            mCameraId = -1;
        }
    }

    return mScannerView;
}


@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    if (requestCode == PERMISSION_REQUEST_CAMERA_SCAN_QR && hasPermission(grantResults)) {
        Logger.logInfo("permission granted");
        mScannerView.setResultHandler(this);
        mScannerView.startCamera(mCameraId);
        mScannerView.setFlash(mFlash);
        mScannerView.setAutoFocus(mAutoFocus);
    }
}

private boolean hasPermission(int[] grantResults) {
    return grantResults.length > 0 && grantResults[0] == PERMISSION_REQUEST_CAMERA_SCAN_QR;
}


@Override
public void onResume() {
    super.onResume();
    mScannerView.setResultHandler(this);
    mScannerView.startCamera(mCameraId);
    mScannerView.setFlash(mFlash);
    mScannerView.setAutoFocus(mAutoFocus);

}

Answer 1

I'd guess that you should ask for the permission, before you initialize ZXingScannerView. Nevertheless i would advise to let the parent activity ask for the permissions. So you just start the ScanSomethingActivity when you have the right permission.

Additionally this library might make your life easier with permission:

https://github.com/googlesamples/easypermissions