plugins/qrscanner.py

   1 from electrum.util import print_error
   2 from urlparse import urlparse, parse_qs
   3 from PyQt4.QtGui import QPushButton, QMessageBox, QDialog, QVBoxLayout, QHBoxLayout, QGridLayout, QLabel, QLineEdit, QComboBox
   4 from PyQt4.QtCore import Qt
   5
   6 from electrum.i18n import _
   7 import re
   8 import os
   9 from electrum import Transaction
  10 from electrum.bitcoin import MIN_RELAY_TX_FEE, is_valid
  11 from electrum_gui.qt.qrcodewidget import QRCodeWidget
  12 from electrum import bmp
  13 from electrum_gui.qt import HelpButton, EnterButton
  14 import json
  15
  16 try:
  17     import zbar
  18 except ImportError:
  19     zbar = None
  20
  21 from electrum import BasePlugin
  22 class Plugin(BasePlugin):
  23
  24     def fullname(self): return 'QR scans'
  25
  26     def description(self): return "QR Scans.\nInstall the zbar package to enable this plugin.\nOn linux, type: 'apt-get install python-zbar'"
  27
  28     def __init__(self, gui, name):
  29         BasePlugin.__init__(self, gui, name)
  30         self._is_available = self._init()
  31
  32     def _init(self):
  33         if not zbar:
  34             return False
  35         try:
  36             proc = zbar.Processor()
  37             proc.init(video_device=self.video_device())
  38         except zbar.SystemError:
  39             # Cannot open video device
  40             pass
  41             #return False
  42
  43         return True
  44
  45     def init(self):
  46         self.win = self.gui.main_window
  47         self.win.raw_transaction_menu.addAction(_("&From QR code"), self.read_raw_qr)
  48         b = QPushButton(_("Scan QR code"))
  49         b.clicked.connect(lambda: self.win.pay_from_URI(self.scan_qr()))
  50         self.win.send_grid.addWidget(b, 1, 5)
  51         self.win.send_grid.setColumnStretch(5, 0)
  52         self.win.send_grid.setColumnStretch(6, 1)
  53
  54     def init_transaction_dialog(self, dialog, buttons):
  55         b = QPushButton(_("Show QR code"))
  56         b.clicked.connect(lambda: self.show_raw_qr(dialog.tx))
  57         buttons.insertWidget(1,b)
  58
  59     def is_available(self):
  60         return self._is_available
  61
  62     def scan_qr(self):
  63         proc = zbar.Processor()
  64         try:
  65             proc.init(video_device=self.video_device())
  66         except zbar.SystemError, e:
  67             QMessageBox.warning(self.win, _('Error'), _(e), _('OK'))
  68             return
  69
  70         proc.visible = True
  71
  72         while True:
  73             try:
  74                 proc.process_one()
  75             except Exception:
  76                 # User closed the preview window
  77                 return {}
  78
  79             for r in proc.results:
  80                 if str(r.type) != 'QRCODE':
  81                     continue
  82                 return r.data
  83
  84     def show_raw_qr(self, tx):
  85         try:
  86             json_text = json.dumps(tx.as_dict()).replace(' ', '')
  87             self.win.show_qrcode(json_text, 'Unsigned Transaction')
  88         except Exception as e:
  89             self.win.show_message(str(e))
  90
  91
  92     def read_raw_qr(self):
  93         qrcode = self.scan_qr()
  94         if not qrcode:
  95             return
  96         tx = self.win.tx_from_text(qrcode)
  97         if not tx:
  98             return
  99         self.win.show_transaction(tx)
 100
 101     def video_device(self):
 102         device = self.config.get("video_device", "default")
 103         if device == 'default':
 104             device = ''
 105         return device
 106
 107     def requires_settings(self):
 108         return True
 109
 110     def settings_widget(self, window):
 111         return EnterButton(_('Settings'), self.settings_dialog)
 112
 113     def _find_system_cameras(self):
 114         device_root = "/sys/class/video4linux"
 115         devices = {} # Name -> device
 116         if os.path.exists(device_root):
 117             for device in os.listdir(device_root):
 118                 name = open(os.path.join(device_root, device, 'name')).read()
 119                 devices[name] = os.path.join("/dev",device)
 120         return devices
 121
 122     def settings_dialog(self):
 123         system_cameras = self._find_system_cameras()
 124
 125         d = QDialog()
 126         layout = QGridLayout(d)
 127         layout.addWidget(QLabel("Choose a video device:"),0,0)
 128
 129         # Create a combo box with the available video devices:
 130         combo = QComboBox()
 131
 132         # on change trigger for video device selection, makes the
 133         # manual device selection only appear when needed:
 134         def on_change(x):
 135             combo_text = str(combo.itemText(x))
 136             combo_data = combo.itemData(x)
 137             if combo_text == "Manually specify a device":
 138                 custom_device_label.setVisible(True)
 139                 self.video_device_edit.setVisible(True)
 140                 if self.config.get("video_device") == "default":
 141                     self.video_device_edit.setText("")
 142                 else:
 143                     self.video_device_edit.setText(self.config.get("video_device"))
 144             else:
 145                 custom_device_label.setVisible(False)
 146                 self.video_device_edit.setVisible(False)
 147                 self.video_device_edit.setText(combo_data.toString())
 148
 149         # on save trigger for the video device selection window,
 150         # stores the chosen video device on close.
 151         def on_save():
 152             device = str(self.video_device_edit.text())
 153             self.config.set_key("video_device", device)
 154             d.accept()
 155
 156         custom_device_label = QLabel("Video device: ")
 157         custom_device_label.setVisible(False)
 158         layout.addWidget(custom_device_label,1,0)
 159         self.video_device_edit = QLineEdit()
 160         self.video_device_edit.setVisible(False)
 161         layout.addWidget(self.video_device_edit, 1,1,2,2)
 162         combo.currentIndexChanged.connect(on_change)
 163
 164         combo.addItem("Default","default")
 165         for camera, device in system_cameras.items():
 166             combo.addItem(camera, device)
 167         combo.addItem("Manually specify a device",self.config.get("video_device"))
 168
 169         # Populate the previously chosen device:
 170         index = combo.findData(self.config.get("video_device"))
 171         combo.setCurrentIndex(index)
 172
 173         layout.addWidget(combo,0,1)
 174
 175         self.accept = QPushButton(_("Done"))
 176         self.accept.clicked.connect(on_save)
 177         layout.addWidget(self.accept,4,2)
 178
 179         if d.exec_():
 180           return True
 181         else:
 182           return False