QRcode reading

[1000i100]

To complete #126, on restore screen, be able to scan back the generated QRcode can be a usage improvement.

[Auronmatrix]

+1

[Auronmatrix]

I've been pondering over this for the last few days. From my pov, the use case would look like this.

0. User opens local seedhodler site
1. The user would print their cold shares for cold storage, the printable cold storage share includes the Raw data QR code for that share
2. When the user want's to restore his shares, he needs to click a "restore from QR" button, which would request permissions to "enable the webcam" in the browser
3. User shows the shares to the webcam and the raw data is extracted and loaded into the share slot on the local seedhodler site

@efnats / @1000i100 does that workflow make sense to you? Anything to add?

As far as I could tell, there is no native web api's that support QR code scanning, but I found a few libs that would work with the getUserMedia API. Support might be lacking though.

Obviously we need to dig deeper into each lib. Ideally, I would like to keep the library dependency tree for this project as low as possible, so some support / testing / investigation is required.

Libs:

• https://github.com/cozmo/jsqr
• https://github.com/mebjas/html5-qrcode
• https://github.com/davidshimjs/qrcodejs
• https://github.com/LazarSoft/jsqrcode
• https://github.com/nimiq/qr-scanner

More sources:

• https://webrtc.github.io/samples/
• https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia

[1000i100]

Great scenario.
I think the printed cold share should include QRCode + SLIP39 text version
And the restore interface should include text field for SLIP39 text + restore from QRCode button

[1000i100]

• jsqr -> unit test exists, last update 30 April 2020
• html5-qrcode -> unit test exists, last update 18 June 2020
• qrcodejs -> no unit test, no update since 2015
• jsqrcode -> no unit test, no update since 2017
• qr-scanner -> no unit test but a benchmark, no update since 17 Feb 2019

[1000i100]

https://github.com/paritytech/banana_split do it (but don't let you choose how many parts you want over how many generated)