gui/qrscanner.py

   1 from electrum.util import print_error
   2
   3 try:
   4     import zbar
   5 except ImportError:
   6     print_error("Install zbar package to enable QR scans")
   7     zbar = None
   8
   9 from urlparse import urlparse, parse_qs
  10
  11 def is_available():
  12     if not zbar:
  13         return False
  14
  15     try:
  16         proc = zbar.Processor()
  17         proc.init()
  18     except zbar.SystemError:
  19         # Cannot open video device
  20         return False
  21
  22     return True
  23
  24 def scan_qr():
  25     proc = zbar.Processor()
  26     proc.init()
  27     proc.visible = True
  28
  29     while True:
  30         try:
  31             proc.process_one()
  32         except:
  33             # User closed the preview window
  34             return {}
  35
  36         for r in proc.results:
  37             if str(r.type) != 'QRCODE':
  38                 continue
  39
  40             return parse_uri(r.data)
  41
  42 def parse_uri(uri):
  43     if ':' not in uri:
  44         # It's just an address (not BIP21)
  45         return {'address': uri}
  46
  47     if '//' not in uri:
  48         # Workaround for urlparse, it don't handle bitcoin: URI properly
  49         uri = uri.replace(':', '://')
  50
  51     uri = urlparse(uri)
  52     result = {'address': uri.netloc}
  53
  54     if uri.path.startswith('?'):
  55         params = parse_qs(uri.path[1:])
  56     else:
  57         params = parse_qs(uri.path)
  58
  59     for k,v in params.items():
  60         if k in ('amount', 'label', 'message'):
  61             result[k] = v[0]
  62
  63     return result
  64
  65 if __name__ == '__main__':
  66     # Run some tests
  67
  68     assert(parse_uri('1Marek48fwU7mugmSe186do2QpUkBnpzSN') ==
  69            {'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
  70
  71     assert(parse_uri('bitcoin://1Marek48fwU7mugmSe186do2QpUkBnpzSN') ==
  72            {'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
  73
  74     assert(parse_uri('bitcoin:1Marek48fwU7mugmSe186do2QpUkBnpzSN') ==
  75            {'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
  76
  77     assert(parse_uri('bitcoin:1Marek48fwU7mugmSe186do2QpUkBnpzSN?amount=10') ==
  78            {'amount': '10', 'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
  79
  80     assert(parse_uri('bitcoin:1Marek48fwU7mugmSe186do2QpUkBnpzSN?amount=10&label=slush&message=Small%20tip%20to%20slush') ==
  81            {'amount': '10', 'label': 'slush', 'message': 'Small tip to slush', 'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
  82
  83