Focus issue about mtbbarcodescanner

[mikebuss]

Thanks for bringing this to my attention. That's a really odd bug.

Maybe changing the autoFocusRangeRestriction back to AVCaptureAutoFocusRangeRestrictionNone in stopScanning is an option?

We can definitely do this. Have you found this fixes the issue? Would you mind testing this on your branch, and maybe submitting a pull request with the one-line change? If you don't have time, let me know and I can try later this week.

If we made this change, how would the library handle crashing while scanning? Would the autoFocusRangeRestriction be stuck on AVCaptureAutoFocusRangeRestrictionNear?

It seems odd to me that UIImagePickerController isn't configuring the AVCaptureDevice returned from defaultDeviceWithMediaType: before capturing video. I'm sure Apple knows others will be configuring the device, and there's no documentation saying we need to revert our changes, so this might be worthy of filing a radar.

[sebastianludwig]

Nope, not fixed.

The currentCaptureDeviceInput reference is only set in setCamera which is not called during the initial setup through newSessionWithCaptureDevice. The other way round the focus range and focus point are not set then switching cameras because that code is only in newCaptureDeviceWithCamera and not in setCamera. That's why I had the setDeviceInput:session: in my PR to do both and had that called from newSessionWithCaptureDevice and setCamera.

[mikebuss]

Good catch. I just pushed a change under version 1.6.1 that should be a lot closer to your initial implementation. Can you give this a try and let me know if this fixes the issue?

Sorry for the back and forth. I'm having a hard time reproducing on my iPhone 6+ or iPad Air (1 and 2).

[sebastianludwig]

Again, I already left work so I'm without test devices, but I had a co-worker test it and he confirmed your fix 👍

[mikebuss]

Great - thanks for all the help!