QR-code scanning not working

[GoogleCodeExporter]

Briefly, QR-code scanning is not working for me, at least for a qr-code that's 
on a computer screen.  I'm using version 3.28-test on an HTC Mytouch 4G Slide, 
a.k.a. "DoubleShot."

What steps will reproduce the problem?
1. Touch "send coins"
2. Touch "scan"
3. Try to scan a qr-code from an lcd computer screen, holding the phone in any 
orientation at any distance, enlarging the image on the screen to any size.

What is the expected output? What do you see instead?

The device repeatedly refocuses every few seconds, never succeeding to scan the 
code.  The red square keeps flashing.

What version of Bitcoin Wallet are you using?
App version 3.28-test
Android version 4.0.4
Device: HTC Mytouch 4G Slide (doubleshot)

Possibly significant I also have tried using other QR scanning applications; 
some behave identically as bitcoin-wallet, but others work.  Specifically:

* QR Droid does not work either
  https://play.google.com/store/apps/details?id=la.droid.qr
  Same as bitcoin-wallet: the device refocuses every second or two, never successfully scanning.

* QuickMark Barcode Scanner works
  https://play.google.com/store/apps/details?id=tw.com.quickmark
  Scans very quickly and correctly, even if the code is out-of-focus.

I don't do a lot of scanning, so maybe I'm doing something wrong, but if so 
it's nothing obvious (to me).

Please let me know if I can provide any more details to help.

Thank you,
--
Adam Mackler

Original issue reported on code.google.com by adammack...@gmail.com on 15 Dec 2013 at 9:35

[GoogleCodeExporter]

Can you try if the ZXing Barcode Scanner works for you? This is the one I 
originally used for Bitcoin Wallet. Does it make a difference if you tick or 
untick the setting "No continuous focus" in ZXing? 

Original comment by andreas....@gmail.com on 15 Dec 2013 at 10:06

[GoogleCodeExporter]

I just tried ZXing Barcode Scanner.  There is no difference.  I manipulated the 
"continuous focus" setting, also the "use auto focus", "1D Barcodes", and 
"Invert scan" settings, in every permutation.

It fails to successfully scan the code, and the focus continues to refocus 
every second or so.

Original comment by adammack...@gmail.com on 15 Dec 2013 at 10:58

[GoogleCodeExporter]

Just out of curiosity, did you try other (non-Bitcoin) QR codes?

I suggest filing an issue with ZXing and see what they say. If they fix the 
problem I can probably just apply the same patch. I'll keep this issue open as 
a reminder.

As a workaround, try using one of the scanners that work and see if they handle 
opening bitcoin URIs properly. Bitcoin Wallet accepts URIs from other apps.

Original comment by andreas....@gmail.com on 15 Dec 2013 at 11:07

• Changed state: Accepted

[GoogleCodeExporter]

I have filed issue zxing issue 1822:

https://code.google.com/p/zxing/issues/detail?id=1822

Per your suggestion I've tested with ten different QR codes, two of which were 
Bitcoin URLs, one having a label.  No difference except QuickMark failed on the 
two (non-Bitcoin) codes that have the most information.  Details are in the 
referenced zxing issue.

Original comment by adammack...@gmail.com on 16 Dec 2013 at 2:24

[GoogleCodeExporter]

If you've been following the progress of the ZXing issue, you know the ticket 
has been closed.  After rigorous technical analysis by the ZXing development 
team, it has been determined that there is no bug in the ZXing Barcode Scanner 
app, which is known with 99% certainty by reason that the ZXing code has been 
worked on my programmers who write only bugless code.  Moreover, there is 
strong evidence of user error, namely the user chose to run the app on a 
defective device, as proven by the fact that the app doesn't run on the device.

Since the developers were able to resolve this non-issue without the necessity 
of making any changes to the ZXing code, there has been nor will be any changes 
with regard hereto.

Original comment by adammack...@gmail.com on 17 Dec 2013 at 4:39