plugins/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
  12 def init(wallet):
  13     pass
  14
  15 def init_gui(gui):
  16     if is_enabled():
  17         gui.wallet.set_hook('create_send_tab', create_send_tab)
  18     else:
  19         gui.wallet.unset_hook('create_send_tab', create_send_tab)
  20
  21 def get_info():
  22     return 'QR scans', "QR Scans"
  23
  24 def is_enabled():
  25     return is_available()
  26
  27 def toggle(gui):
  28     return is_enabled()
  29
  30
  31 def is_available():
  32     if not zbar:
  33         return False
  34
  35     try:
  36         proc = zbar.Processor()
  37         proc.init()
  38     except zbar.SystemError:
  39         # Cannot open video device
  40         return False
  41
  42     return True
  43
  44 def scan_qr():
  45     proc = zbar.Processor()
  46     proc.init()
  47     proc.visible = True
  48
  49     while True:
  50         try:
  51             proc.process_one()
  52         except:
  53             # User closed the preview window
  54             return {}
  55
  56         for r in proc.results:
  57             if str(r.type) != 'QRCODE':
  58                 continue
  59
  60             return parse_uri(r.data)
  61
  62 def parse_uri(uri):
  63     if ':' not in uri:
  64         # It's just an address (not BIP21)
  65         return {'address': uri}
  66
  67     if '//' not in uri:
  68         # Workaround for urlparse, it don't handle bitcoin: URI properly
  69         uri = uri.replace(':', '://')
  70
  71     uri = urlparse(uri)
  72     result = {'address': uri.netloc}
  73
  74     if uri.path.startswith('?'):
  75         params = parse_qs(uri.path[1:])
  76     else:
  77         params = parse_qs(uri.path)
  78
  79     for k,v in params.items():
  80         if k in ('amount', 'label', 'message'):
  81             result[k] = v[0]
  82
  83     return result
  84
  85
  86
  87 def fill_from_qr(self):
  88     qrcode = qrscanner.scan_qr()
  89     if 'address' in qrcode:
  90         self.payto_e.setText(qrcode['address'])
  91     if 'amount' in qrcode:
  92         self.amount_e.setText(str(qrcode['amount']))
  93     if 'label' in qrcode:
  94         self.message_e.setText(qrcode['label'])
  95     if 'message' in qrcode:
  96         self.message_e.setText("%s (%s)" % (self.message_e.text(), qrcode['message']))
  97
  98
  99 def create_send_tab(gui, grid):
 100     if qrscanner.is_available():
 101         b = QPushButton(_("Scan QR code"))
 102         b.clicked.connect(lambda: fill_from_qr(gui))
 103         grid.addWidget(b, 1, 5)
 104
 105
 106
 107 if __name__ == '__main__':
 108     # Run some tests
 109
 110     assert(parse_uri('1Marek48fwU7mugmSe186do2QpUkBnpzSN') ==
 111            {'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
 112
 113     assert(parse_uri('bitcoin://1Marek48fwU7mugmSe186do2QpUkBnpzSN') ==
 114            {'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
 115
 116     assert(parse_uri('bitcoin:1Marek48fwU7mugmSe186do2QpUkBnpzSN') ==
 117            {'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
 118
 119     assert(parse_uri('bitcoin:1Marek48fwU7mugmSe186do2QpUkBnpzSN?amount=10') ==
 120            {'amount': '10', 'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
 121
 122     assert(parse_uri('bitcoin:1Marek48fwU7mugmSe186do2QpUkBnpzSN?amount=10&label=slush&message=Small%20tip%20to%20slush') ==
 123            {'amount': '10', 'label': 'slush', 'message': 'Small tip to slush', 'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
 124
 125