Send tab: scan QR from screen and/or image

[mpeter50]

The scan function currently allows scanning the transaction details from a connected camera for quick input.
However, when there is no camera connected, the function does not work, and laptop users with a built-in camera can only scan from their phone, paper, or some other surface.

I think that for online shopping, it would be useful to be able to scan the code from the screen, for when it is displayed in a web browser, or from an image file without opening it in an image viewer.
Extending the scan feature like this would benefit desktop and laptop users too.

[tobtoht]

You can paste a QR code into the 'Pay to' field on the Send tab and it will auto-fill the details.

I'll have to check if scanning the screen can be implemented reliably cross-platform.

[mpeter50]

Oh, thats pretty useful! Thanks for letting me know. I see it can process monero: protocol URLs.

Now I also see it is mentioned in the built-in docs. I think it would be worth to consider making this information more visible, e.g. with an information button or popup near the "Pay to" label. I have just discovered that label is clickable, maybe the short description could be extended with "or paste a QR code".

The Monero GUI has a "Grab QR code from screen" button above the address field, maybe their approach can be reused here.

[chaserene]

I'll have to check if scanning the screen can be implemented reliably cross-platform.

@tobtoht beyond that, I wonder if it can be implemented safely. wouldn't it be a radical extension of Feather's permissions to let it read any area of the screen?

[mpeter50]

I dont think it would be an extension of permissions. Any process can do that, cant it?
Unless you are thinking about Flatpak and such on linux. Or maybe Sandboxie on windows, but I'm not sure how does it work there, probably not with a permission dialog though.

[tobtoht]

I'm going to mark this as 'not planned', because there are too many environments in which this won't work as expected (without requiring additional permissions): Linux under Wayland, Flatpak, sandboxes, Qubes, and probably macOS.

On Windows, applications can request to be excluded from a screen capture (e.g. KeePassXC on Windows). Likewise, DRM-enabled applications will not show up on screenshots. However unlikely, if the QR code is present here we can't give the user feedback on why no QR code was found. I'm sure there are more edge cases where this could cause frustration.

I will keep this issue open until the ability to paste QR codes in the 'Pay To' field is better documented / more visible.