Merge branch 'master' of ssh://github.com/spesmilo/electrum

RELEASE-NOTES

@@ -2,9 +2,7 @@
 
 * The client connects to multiple servers in order to retrieve block headers and find the longest chain
 * SSL certificate validation (to prevent MITM)
-* Implements BIP32 (hierarchical deterministic wallet)
 * Deterministic signatures (RFC 6979)
-* Can create multiple accounts in the same wallet
 * Menu to create/restore/open wallets
 * Create transactions with multiple outputs from CSV (comma separated values)
 * New text gui: stdio

electrum

@@ -349,31 +349,29 @@ if __name__ == '__main__':
         if not wallet.seed:
             print_msg("Error: This wallet has no seed")
         else:
-            ns = wallet.config.path + '.seedless'
+            ns = wallet.storage.path + '.seedless'
             print_msg("Warning: you are going to create a seedless wallet'\nIt will be saved in '%s'"%ns)
             if raw_input("Are you sure you want to continue? (y/n) ") in ['y','Y','yes']:
-                wallet.config.path = ns
+                wallet.storage.path = ns
                 wallet.seed = ''
                 wallet.storage.put('seed', '', True)
                 wallet.use_encryption = False
                 wallet.storage.put('use_encryption', wallet.use_encryption, True)
                 for k in wallet.imported_keys.keys(): wallet.imported_keys[k] = ''
-                wallet.config.set_key('imported_keys',wallet.imported_keys, True)
+                wallet.storage.put('imported_keys',wallet.imported_keys, True)
                 print_msg("Done.")
             else:
                 print_msg("Action canceled.")
 
     elif cmd.name == 'getconfig':
         key = args[1]
-        print_msg(config.get(key))
+        out = config.get(key)
+        print_msg(out)
 
     elif cmd.name == 'setconfig':
         key, value = args[1:3]
-        if key not in ['seed', 'seed_version', 'master_public_key', 'use_encryption']:
+        config.set_key(key, value, True)
-            config.set_key(key, value, True)
+        print_msg(True)
-            print_msg(True)
-        else:
-            print_msg(False)
 
     elif cmd.name == 'password':
         new_password = prompt_password('New password:')

gui/qt/installwizard.py

@@ -24,6 +24,15 @@ class InstallWizard(QDialog):
         self.setWindowTitle('Electrum')
         self.connect(self, QtCore.SIGNAL('accept'), self.accept)
 
+        self.stack = QStackedLayout()
+        self.setLayout(self.stack)
+
+
+    def set_layout(self, layout):
+        w = QWidget()
+        w.setLayout(layout)
+        self.stack.setCurrentIndex(self.stack.addWidget(w))
+
 
     def restore_or_create(self):
 
@@ -51,9 +60,10 @@ class InstallWizard(QDialog):
         grid.addWidget(b2,2,0)
         grid.addWidget(b3,3,0)
 
-        vbox = QVBoxLayout(self)
+        vbox = QVBoxLayout()
-        vbox.addLayout(grid)
+        self.set_layout(vbox)
 
+        vbox.addLayout(grid)
         vbox.addStretch(1)
         vbox.addLayout(ok_cancel_buttons(self, _('Next')))
 
@@ -84,9 +94,7 @@ class InstallWizard(QDialog):
 
     def seed_dialog(self, is_restore=True):
 
-        if self.layout(): QWidget().setLayout(self.layout())
+        vbox = QVBoxLayout()
-
-        vbox = QVBoxLayout(self)
         if is_restore:
             msg = _("Please enter your wallet seed.") + "\n"
         else:
@@ -111,10 +119,10 @@ class InstallWizard(QDialog):
 
         vbox.addLayout(grid)
 
-
         vbox.addStretch(1)
         vbox.addLayout(ok_cancel_buttons(self, _('Next')))
 
+        self.set_layout(vbox)
         if not self.exec_():
             return
 
@@ -133,10 +141,10 @@ class InstallWizard(QDialog):
             task()
             self.emit(QtCore.SIGNAL('accept'))
 
-        if self.layout(): QWidget().setLayout(self.layout())
+        vbox = QVBoxLayout()
-        vbox = QVBoxLayout(self)
         self.waiting_label = QLabel(msg)
         vbox.addWidget(self.waiting_label)
+        self.set_layout(vbox)
         t = threading.Thread(target = target)
         t.start()
         self.exec_()
@@ -145,10 +153,7 @@ class InstallWizard(QDialog):
 
     def mpk_dialog(self):
 
-        if self.layout(): QWidget().setLayout(self.layout())
+        vbox = QVBoxLayout()
-
-        vbox = QVBoxLayout(self)
-
         vbox.addWidget(QLabel(_("Please enter your master public key.")))
 
         grid = QGridLayout()
@@ -161,16 +166,17 @@ class InstallWizard(QDialog):
         grid.addWidget(mpk_e, 0, 1)
 
         label = QLabel(_("Chain")) 
-        grid.addWidget(label, 1, 0)
+        #grid.addWidget(label, 1, 0)
         chain_e = QTextEdit()
         chain_e.setMaximumHeight(100)
-        grid.addWidget(chain_e, 1, 1)
+        #grid.addWidget(chain_e, 1, 1)
 
         vbox.addLayout(grid)
 
         vbox.addStretch(1)
         vbox.addLayout(ok_cancel_buttons(self, _('Next')))
 
+        self.set_layout(vbox)
         if not self.exec_(): return None, None
 
         mpk = str(mpk_e.toPlainText()).strip()
@@ -180,8 +186,6 @@ class InstallWizard(QDialog):
 
     def network_dialog(self):
         
-        if self.layout(): QWidget().setLayout(self.layout())
-
         grid = QGridLayout()
         grid.setSpacing(5)
 
@@ -206,12 +210,13 @@ class InstallWizard(QDialog):
         grid.addWidget(b2,2,0)
         #grid.addWidget(b3,3,0)
 
-        vbox = QVBoxLayout(self)
+        vbox = QVBoxLayout()
         vbox.addLayout(grid)
 
         vbox.addStretch(1)
         vbox.addLayout(ok_cancel_buttons(self, _('Next')))
 
+        self.set_layout(vbox)
         if not self.exec_():
             return
         
@@ -235,9 +240,7 @@ class InstallWizard(QDialog):
         vbox = make_seed_dialog(wallet.get_mnemonic(None), wallet.imported_keys)
         vbox.addLayout(ok_cancel_buttons(self, _("Next")))
 
-        if self.layout(): QWidget().setLayout(self.layout())
+        self.set_layout(vbox)
-        self.setLayout(vbox)
-
         if not self.exec_():
             exit()
 
@@ -246,8 +249,8 @@ class InstallWizard(QDialog):
         msg = _("Please choose a password to encrypt your wallet keys.")+'\n'\
               +_("Leave these fields empty if you want to disable encryption.")
         from password_dialog import make_password_dialog, run_password_dialog
-        if self.layout(): QWidget().setLayout(self.layout())
+        self.set_layout( make_password_dialog(self, wallet, msg) )
-        make_password_dialog(self, wallet, msg)
+
         run_password_dialog(self, wallet, self)
 
 
@@ -291,11 +294,11 @@ class InstallWizard(QDialog):
 
         elif action == 'watching':
             # ask for seed and gap.
-            K, chain = self.mpk_dialog()
+            mpk = self.mpk_dialog()
-            if not K or not chain:
+            if not mpk:
                 return
             wallet.seed = ''
-            wallet.create_watching_only_wallet(chain,K)
+            wallet.create_watching_only_wallet(mpk)
 
 
         else: raise

gui/qt/main_window.py

@@ -219,6 +219,7 @@ class ElectrumWindow(QMainWindow):
                 self.config.set_key('lite_mode', False, True)
                 sys.exit(0)
             self.mini = None
+            self.show()
             return
 
         actuator = lite_window.MiniActuator(self)
@@ -792,7 +793,7 @@ class ElectrumWindow(QMainWindow):
                 c, u = self.wallet.get_account_balance(self.current_account)
                 inputs, total, fee = self.wallet.choose_tx_inputs_from_account( c + u, 0, self.current_account)
                 fee = self.wallet.estimated_fee(inputs)
-                amount = c + u - fee
+                amount = total - fee
                 self.amount_e.setText( self.format_amount(amount) )
                 self.fee_e.setText( self.format_amount( fee ) )
                 return

gui/qt/password_dialog.py

@@ -68,7 +68,7 @@ def make_password_dialog(self, wallet, msg):
 
     vbox.addStretch(1)
     vbox.addLayout(ok_cancel_buttons(self))
-    self.setLayout(vbox) 
+    return vbox
 
 
 def run_password_dialog(self, wallet, parent):
@@ -119,7 +119,7 @@ class PasswordDialog(QDialog):
         msg = (_('Your wallet is encrypted. Use this dialog to change your password.') + ' '\
                +_('To disable wallet encryption, enter an empty new password.')) \
                if wallet.use_encryption else _('Your wallet keys are not encrypted')
-        make_password_dialog(self, wallet, msg)
+        self.setLayout(make_password_dialog(self, wallet, msg))
 
 
     def run(self):

lib/commands.py

@@ -74,6 +74,7 @@ register_command('getconfig',            1, 1, False, False, False, 'Return a co
 register_command('getpubkeys',           1, 1, False, True,  False, 'Return the public keys for a wallet address', 'getpubkeys <bitcoin address>')
 register_command('getrawtransaction',    1, 2, True,  False, False, 'Retrieve a transaction', 'getrawtransaction <txhash> <height>')
 register_command('getseed',              0, 0, False, True,  True,  'Print the generation seed of your wallet.')
+register_command('getmpk',               0, 0, False, True,  False, 'Return your wallet\'s master public key', 'getmpk')
 register_command('help',                 0, 1, False, False, False, 'Prints this help')
 register_command('history',              0, 0, True,  True,  False, 'Returns the transaction history of your wallet')
 register_command('importprivkey',        1, 1, False, True,  True,  'Import a private key', 'importprivkey <privatekey>')
@@ -214,6 +215,9 @@ class Commands:
     def getservers(self):
         return self.network.get_servers()
 
+    def getmpk(self):
+        return self.wallet.get_master_public_key()
+
     def getseed(self):
         mnemonic = self.wallet.get_mnemonic(self.password)
         seed = self.wallet.get_seed(self.password)

lib/network.py

@@ -258,7 +258,6 @@ class Network(threading.Thread):
 
 
     def new_blockchain_height(self, blockchain_height, i):
-        print_error('new_blockchain_height')
         if self.is_connected():
             h = self.heights.get(self.interface.server)
             if h:

lib/transaction.py

@@ -432,10 +432,12 @@ class Transaction:
                 pubkeys = txin['pubkeys']
                 if not txin.get('redeemScript'):
                     pubkey = pubkeys[0]
-                    sig = signatures[0]
+                    script = ''
-                    sig = sig + '01'                                 # hashtype
+                    if signatures:
-                    script  = op_push(len(sig)/2)
+                        sig = signatures[0]
-                    script += sig
+                        sig = sig + '01'                                 # hashtype
+                        script += op_push(len(sig)/2)
+                        script += sig
                     script += op_push(len(pubkey)/2)
                     script += pubkey
                 else:
@@ -720,6 +722,7 @@ class Transaction:
         for i, txin in enumerate(self.inputs):
             item = input_info[i]
             txin['address'] = item['address']
+            txin['signatures'] = item['signatures']
             txin['scriptPubKey'] = item['scriptPubKey']
             txin['redeemScript'] = item.get('redeemScript')
             txin['redeemPubkey'] = item.get('redeemPubkey')

lib/version.py

@@ -2,4 +2,4 @@ ELECTRUM_VERSION = "1.9"    # version of the client package
 PROTOCOL_VERSION = '0.6'    # protocol version requested
 SEED_VERSION     = 6        # bump this every time the seed generation is modified
 SEED_PREFIX      = '01'     # the hash of the mnemonic seed must begin with this
-TRANSLATION_ID   = 4127     # version of the wiki page 
+TRANSLATION_ID   = 4141     # version of the wiki page 

lib/wallet.py

@@ -311,6 +311,7 @@ class Wallet:
         try:
             seed.decode('hex')
             self.seed_version = 4
+            self.seed = str(seed)
             return
         except:
             pass
@@ -338,7 +339,16 @@ class Wallet:
         self.storage.put('seed', self.seed, True)
         self.storage.put('seed_version', self.seed_version, True)
 
-    def create_watching_only_wallet(self, c0, K0):
+    def create_watching_only_wallet(self, params):
+        K0, c0 = params
+        if not K0:
+            return
+
+        if not c0:
+            self.seed_version = 4
+            self.create_old_account(K0)
+            return
+
         cK0 = ""
         self.master_public_keys = {
             "m/0'/": (c0, K0, cK0),
@@ -349,7 +359,8 @@ class Wallet:
 
     def create_accounts(self): 
         if self.seed_version == 4:
-            self.create_old_account()
+            mpk = OldAccount.mpk_from_seed(self.seed)
+            self.create_old_account(mpk)
         else:
             # create default account
             self.create_master_keys('1')
@@ -512,8 +523,7 @@ class Wallet:
             self.set_label(k, name)
 
 
-    def create_old_account(self):
+    def create_old_account(self, mpk):
-        mpk = OldAccount.mpk_from_seed(self.seed)
         self.storage.put('master_public_key', mpk, True)
         self.accounts[0] = OldAccount({'mpk':mpk, 0:[], 1:[]})
         self.save_accounts()
@@ -649,7 +659,9 @@ class Wallet:
 
     def get_keyID(self, account, sequence):
         if account == 0:
-            return 'old'
+            a, b = sequence
+            mpk = self.storage.get('master_public_key')
+            return 'old(%s,%d,%d)'%(mpk,a,b)
 
         rs = self.rebase_sequence(account, sequence)
         dd = []
@@ -713,12 +725,32 @@ class Wallet:
             for sec in private_keys:
                 pubkey = public_key_from_private_key(sec)
                 keypairs[ pubkey ] = sec
+                if address in self.imported_keys.keys():
+                    txin['redeemPubkey'] = pubkey
 
 
     def add_keypairs_from_KeyID(self, tx, keypairs, password):
         for txin in tx.inputs:
             keyid = txin.get('KeyID')
             if keyid:
+
+                if self.seed_version==4:
+                    m = re.match("old\(([0-9a-f]+),(\d+),(\d+)", keyid)
+                    if not m: continue
+                    mpk = m.group(1)
+                    if mpk != self.storage.get('master_public_key'): continue 
+                    index = int(m.group(2))
+                    num = int(m.group(3))
+                    account = self.accounts[0]
+                    addr = account.get_address(index, num)
+                    txin['address'] = addr # fixme: side effect
+                    pk = self.get_private_key(addr, password)
+                    for sec in pk:
+                        pubkey = public_key_from_private_key(sec)
+                        keypairs[pubkey] = sec
+                    continue
+
+
                 roots = []
                 for s in keyid.split('&'):
                     m = re.match("bip32\(([0-9a-f]+),([0-9a-f]+),(/\d+/\d+/\d+)", s)
@@ -1328,6 +1360,8 @@ class Wallet:
     def add_input_info(self, inputs):
         for txin in inputs:
             address = txin['address']
+            if address in self.imported_keys.keys():
+                continue
             account, sequence = self.get_address_index(address)
             txin['KeyID'] = self.get_keyID(account, sequence)
             redeemScript = self.accounts[account].redeem_script(sequence)
@@ -1553,7 +1587,7 @@ class Wallet:
                 time.sleep(0.1)
 
         def wait_for_network():
-            while not self.network.interface.is_connected:
+            while not self.network.is_connected():
                 msg = "%s \n" % (_("Connecting..."))
                 apply(callback, (msg,))
                 time.sleep(0.1)

plugins/qrscanner.py

@@ -1,14 +1,16 @@
 from electrum.util import print_error
 from urlparse import urlparse, parse_qs
-from PyQt4.QtGui import QPushButton, QMessageBox, QDialog, QVBoxLayout, QHBoxLayout, QGridLayout, QLabel
+from PyQt4.QtGui import QPushButton, QMessageBox, QDialog, QVBoxLayout, QHBoxLayout, QGridLayout, QLabel, QLineEdit, QComboBox
 from PyQt4.QtCore import Qt
 
 from electrum.i18n import _
 import re
+import os
 from electrum import Transaction
 from electrum.bitcoin import MIN_RELAY_TX_FEE, is_valid
 from electrum_gui.qt.qrcodewidget import QRCodeWidget
 from electrum import bmp
+from electrum_gui.qt import HelpButton, EnterButton
 import json
 
 try:
@@ -32,35 +34,43 @@ class Plugin(BasePlugin):
             return False
         try:
             proc = zbar.Processor()
-            proc.init()
+            proc.init(video_device=self.video_device())
         except zbar.SystemError:
             # Cannot open video device
-            return False
+            pass
+            #return False
 
         return True
 
-    def is_available(self):
+    def load_wallet(self, wallet):
-        return self._is_available
-
-    def create_send_tab(self, grid):
         b = QPushButton(_("Scan QR code"))
         b.clicked.connect(self.fill_from_qr)
-        grid.addWidget(b, 1, 5)
+        self.send_tab_grid.addWidget(b, 1, 5)
         b2 = QPushButton(_("Scan TxQR"))
         b2.clicked.connect(self.read_raw_qr)
         
-        if not self.gui.wallet.seed:
+        if not wallet.seed:
             b3 = QPushButton(_("Show unsigned TxQR"))
             b3.clicked.connect(self.show_raw_qr)
-            grid.addWidget(b3, 7, 1)
+            self.send_tab_grid.addWidget(b3, 7, 1)
-            grid.addWidget(b2, 7, 2)
+            self.send_tab_grid.addWidget(b2, 7, 2)
         else:
-            grid.addWidget(b2, 7, 1)
+            self.send_tab_grid.addWidget(b2, 7, 1)
 
+    def is_available(self):
+        return self._is_available
+
+    def create_send_tab(self, grid):
+        self.send_tab_grid = grid
 
     def scan_qr(self):
         proc = zbar.Processor()
-        proc.init()
+        try:
+            proc.init(video_device=self.video_device())
+        except zbar.SystemError, e:
+            QMessageBox.warning(self.gui.main_window, _('Error'), _(e), _('OK'))
+            return
+
         proc.visible = True
 
         while True:
@@ -76,7 +86,7 @@ class Plugin(BasePlugin):
                 return r.data
         
     def show_raw_qr(self):
-        r = unicode( self.gui.payto_e.text() )
+        r = unicode( self.gui.main_window.payto_e.text() )
         r = r.strip()
 
         # label or alias, with address in brackets
@@ -84,28 +94,28 @@ class Plugin(BasePlugin):
         to_address = m.group(2) if m else r
 
         if not is_valid(to_address):
-            QMessageBox.warning(self.gui, _('Error'), _('Invalid Bitcoin Address') + ':\n' + to_address, _('OK'))
+            QMessageBox.warning(self.gui.main_window, _('Error'), _('Invalid Bitcoin Address') + ':\n' + to_address, _('OK'))
             return
 
         try:
-            amount = self.gui.read_amount(unicode( self.gui.amount_e.text()))
+            amount = self.gui.main_window.read_amount(unicode( self.gui.main_window.amount_e.text()))
         except:
-            QMessageBox.warning(self.gui, _('Error'), _('Invalid Amount'), _('OK'))
+            QMessageBox.warning(self.gui.main_window, _('Error'), _('Invalid Amount'), _('OK'))
             return
         try:
-            fee = self.gui.read_amount(unicode( self.gui.fee_e.text()))
+            fee = self.gui.main_window.read_amount(unicode( self.gui.main_window.fee_e.text()))
         except:
-            QMessageBox.warning(self.gui, _('Error'), _('Invalid Fee'), _('OK'))
+            QMessageBox.warning(self.gui.main_window, _('Error'), _('Invalid Fee'), _('OK'))
             return
 
         try:
-            tx = self.gui.wallet.mktx( [(to_address, amount)], None, fee, account=self.gui.current_account)
+            tx = self.gui.main_window.wallet.mktx( [(to_address, amount)], None, fee)
         except BaseException, e:
-            self.gui.show_message(str(e))
+            self.gui.main_window.show_message(str(e))
             return
 
-        if tx.requires_fee(self.gui.wallet.verifier) and fee < MIN_RELAY_TX_FEE:
+        if tx.requires_fee(self.gui.main_window.wallet.verifier) and fee < MIN_RELAY_TX_FEE:
-            QMessageBox.warning(self.gui, _('Error'), _("This transaction requires a higher fee, or it will not be propagated by the network."), _('OK'))
+            QMessageBox.warning(self.gui.main_window, _('Error'), _("This transaction requires a higher fee, or it will not be propagated by the network."), _('OK'))
             return
 
         try:
@@ -117,17 +127,17 @@ class Plugin(BasePlugin):
             input_info = []
 
         except BaseException, e:
-            self.gui.show_message(str(e))
+            self.gui.main_window.show_message(str(e))
 
         try:
             json_text = json.dumps(tx.as_dict()).replace(' ', '')
             self.show_tx_qrcode(json_text, 'Unsigned Transaction')
         except BaseException, e:
-            self.gui.show_message(str(e))
+            self.gui.main_window.show_message(str(e))
 
     def show_tx_qrcode(self, data, title):
         if not data: return
-        d = QDialog(self.gui)
+        d = QDialog(self.gui.main_window)
         d.setModal(1)
         d.setWindowTitle(title)
         d.setMinimumSize(250, 525)
@@ -158,15 +168,12 @@ class Plugin(BasePlugin):
     def read_raw_qr(self):
         qrcode = self.scan_qr()
         if qrcode:
-            tx_dict = self.gui.tx_dict_from_text(qrcode)
+            tx = self.gui.main_window.tx_from_text(qrcode)
-            if tx_dict:
+            if tx:
-                self.create_transaction_details_window(tx_dict)
+                self.create_transaction_details_window(tx)
-
 
-    def create_transaction_details_window(self, tx_dict):
+    def create_transaction_details_window(self, tx):            
-        tx = Transaction(tx_dict["hex"])
+        dialog = QDialog(self.gui.main_window)
-            
-        dialog = QDialog(self.gui)
         dialog.setMinimumWidth(500)
         dialog.setWindowTitle(_('Process Offline transaction'))
         dialog.setModal(1)
@@ -177,22 +184,28 @@ class Plugin(BasePlugin):
         l.addWidget(QLabel(_("Transaction status:")), 3,0)
         l.addWidget(QLabel(_("Actions")), 4,0)
 
-        if tx_dict["complete"] == False:
+        if tx.is_complete == False:
             l.addWidget(QLabel(_("Unsigned")), 3,1)
-            if self.gui.wallet.seed :
+            if self.gui.main_window.wallet.seed :
                 b = QPushButton("Sign transaction")
-                input_info = json.loads(tx_dict["input_info"])
+                b.clicked.connect(lambda: self.sign_raw_transaction(tx, tx.inputs, dialog))
-                b.clicked.connect(lambda: self.sign_raw_transaction(tx, input_info, dialog))
                 l.addWidget(b, 4, 1)
             else:
                 l.addWidget(QLabel(_("Wallet is de-seeded, can't sign.")), 4,1)
         else:
             l.addWidget(QLabel(_("Signed")), 3,1)
             b = QPushButton("Broadcast transaction")
-            b.clicked.connect(lambda: self.gui.send_raw_transaction(tx, dialog))
+            def broadcast(tx):
+                result, result_message = self.gui.main_window.wallet.sendtx( tx )
+                if result:
+                    self.gui.main_window.show_message(_("Transaction successfully sent:")+' %s' % (result_message))
+                    if dialog:
+                        dialog.done(0)
+                else:
+                    self.gui.main_window.show_message(_("There was a problem sending your transaction:") + '\n %s' % (result_message))
+            b.clicked.connect(lambda: broadcast( tx ))
             l.addWidget(b,4,1)
     
-        l.addWidget( self.gui.generate_transaction_information_widget(tx), 0,0,2,3)
         closeButton = QPushButton(_("Close"))
         closeButton.clicked.connect(lambda: dialog.done(0))
         l.addWidget(closeButton, 4,2)
@@ -200,8 +213,8 @@ class Plugin(BasePlugin):
         dialog.exec_()
 
     def do_protect(self, func, args):
-        if self.gui.wallet.use_encryption:
+        if self.gui.main_window.wallet.use_encryption:
-            password = self.gui.password_dialog()
+            password = self.gui.main_window.password_dialog()
             if not password:
                 return
         else:
@@ -219,11 +232,11 @@ class Plugin(BasePlugin):
     @protected
     def sign_raw_transaction(self, tx, input_info, dialog ="", password = ""):
         try:
-            self.gui.wallet.signrawtransaction(tx, input_info, [], password)
+            self.gui.main_window.wallet.signrawtransaction(tx, input_info, [], password)
             txtext = json.dumps(tx.as_dict()).replace(' ', '')
             self.show_tx_qrcode(txtext, 'Signed Transaction')
         except BaseException, e:
-            self.gui.show_message(str(e))
+            self.gui.main_window.show_message(str(e))
 
 
     def fill_from_qr(self):
@@ -232,14 +245,96 @@ class Plugin(BasePlugin):
             return
 
         if 'address' in qrcode:
-            self.gui.payto_e.setText(qrcode['address'])
+            self.gui.main_window.payto_e.setText(qrcode['address'])
         if 'amount' in qrcode:
-            self.gui.amount_e.setText(str(qrcode['amount']))
+            self.gui.main_window.amount_e.setText(str(qrcode['amount']))
         if 'label' in qrcode:
-            self.gui.message_e.setText(qrcode['label'])
+            self.gui.main_window.message_e.setText(qrcode['label'])
         if 'message' in qrcode:
-            self.gui.message_e.setText("%s (%s)" % (self.gui.message_e.text(), qrcode['message']))
+            self.gui.main_window.message_e.setText("%s (%s)" % (self.gui.main_window.message_e.text(), qrcode['message']))
+                
+    def video_device(self):
+        device = self.config.get("video_device", "default")
+        if device == 'default':
+            device = ''
+        return device
 
+    def requires_settings(self):
+        return True
+
+    def settings_widget(self, window):
+        return EnterButton(_('Settings'), self.settings_dialog)
+    
+    def _find_system_cameras(self):
+        device_root = "/sys/class/video4linux"
+        devices = {} # Name -> device
+        if os.path.exists(device_root):
+            for device in os.listdir(device_root):
+                name = open(os.path.join(device_root, device, 'name')).read()
+                devices[name] = os.path.join("/dev",device)
+        return devices
+
+    def settings_dialog(self):
+        system_cameras = self._find_system_cameras()
+
+        d = QDialog()
+        layout = QGridLayout(d)
+        layout.addWidget(QLabel("Choose a video device:"),0,0)
+
+        # Create a combo box with the available video devices:
+        combo = QComboBox()
+
+        # on change trigger for video device selection, makes the
+        # manual device selection only appear when needed:
+        def on_change(x):
+            combo_text = str(combo.itemText(x))
+            combo_data = combo.itemData(x)
+            if combo_text == "Manually specify a device":
+                custom_device_label.setVisible(True)
+                self.video_device_edit.setVisible(True)
+                if self.config.get("video_device") == "default":
+                    self.video_device_edit.setText("")
+                else:
+                    self.video_device_edit.setText(self.config.get("video_device"))
+            else:
+                custom_device_label.setVisible(False)
+                self.video_device_edit.setVisible(False)
+                self.video_device_edit.setText(combo_data.toString())
+
+        # on save trigger for the video device selection window,
+        # stores the chosen video device on close.
+        def on_save():
+            device = str(self.video_device_edit.text())
+            self.config.set_key("video_device", device)
+            d.accept()
+
+        custom_device_label = QLabel("Video device: ")
+        custom_device_label.setVisible(False)
+        layout.addWidget(custom_device_label,1,0)
+        self.video_device_edit = QLineEdit()
+        self.video_device_edit.setVisible(False)
+        layout.addWidget(self.video_device_edit, 1,1,2,2)
+        combo.currentIndexChanged.connect(on_change)
+
+        combo.addItem("Default","default")
+        for camera, device in system_cameras.items():
+            combo.addItem(camera, device)
+        combo.addItem("Manually specify a device",self.config.get("video_device"))
+
+        # Populate the previously chosen device:
+        index = combo.findData(self.config.get("video_device"))
+        combo.setCurrentIndex(index)
+
+        layout.addWidget(combo,0,1)
+
+        self.accept = QPushButton(_("Done"))
+        self.accept.clicked.connect(on_save)
+        layout.addWidget(self.accept,4,2)
+
+        if d.exec_():
+          return True
+        else:
+          return False