#!/usr/bin/env python
#
# Electrum - lightweight Bitcoin client
# Copyright (C) 2012 thomasv@gitorious
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

import sys, time, datetime, re, threading
from electrum.i18n import _, set_language
from electrum.util import print_error, print_msg
import os.path, json, ast, traceback
import webbrowser
import shutil
import StringIO


import PyQt4
from PyQt4.QtGui import *
from PyQt4.QtCore import *
import PyQt4.QtCore as QtCore

from electrum.bitcoin import MIN_RELAY_TX_FEE, is_valid
from electrum.plugins import run_hook

import icons_rc

from electrum.util import format_satoshis, NotEnoughFunds
from electrum import Transaction
from electrum import mnemonic
from electrum import util, bitcoin, commands, Interface, Wallet
from electrum import SimpleConfig, Wallet, WalletStorage
from electrum import Imported_Wallet

from amountedit import AmountEdit, BTCAmountEdit, MyLineEdit
from network_dialog import NetworkDialog
from qrcodewidget import QRCodeWidget, QRDialog
from qrtextedit import ScanQRTextEdit, ShowQRTextEdit

from decimal import Decimal

import httplib
import socket
import webbrowser
import csv





from electrum import ELECTRUM_VERSION
import re

from util import MyTreeWidget, HelpButton, EnterButton, line_dialog, text_dialog, ok_cancel_buttons, close_button, WaitingDialog
from util import filename_field, ok_cancel_buttons2, address_field
from util import MONOSPACE_FONT



class StatusBarButton(QPushButton):
    def __init__(self, icon, tooltip, func):
        QPushButton.__init__(self, icon, '')
        self.setToolTip(tooltip)
        self.setFlat(True)
        self.setMaximumWidth(25)
        self.clicked.connect(func)
        self.func = func
        self.setIconSize(QSize(25,25))

    def keyPressEvent(self, e):
        if e.key() == QtCore.Qt.Key_Return:
            apply(self.func,())



default_column_widths = {
    "history":[40,140,350,140],
    "contacts":[350,330],
    "receive": [370,200,130]
}

# status of payment requests
PR_UNPAID  = 0
PR_EXPIRED = 1
PR_SENT    = 2     # sent but not propagated
PR_PAID    = 3     # send and propagated
PR_ERROR   = 4     # could not parse

pr_icons = {
    PR_UNPAID:":icons/unpaid.png",
    PR_PAID:":icons/confirmed.png",
    PR_EXPIRED:":icons/expired.png"
}
pr_tooltips = {
    PR_UNPAID:_('Unpaid'),
    PR_PAID:_('Paid'),
    PR_EXPIRED:_('Expired')
}



class ElectrumWindow(QMainWindow):
    labelsChanged = pyqtSignal()

    def __init__(self, config, network, gui_object):
        QMainWindow.__init__(self)

        self.config = config
        self.network = network
        self.gui_object = gui_object
        self.tray = gui_object.tray
        self.go_lite = gui_object.go_lite
        self.lite = None

        self.create_status_bar()
        self.need_update = threading.Event()

        self.decimal_point = config.get('decimal_point', 5)
        self.num_zeros     = int(config.get('num_zeros',0))
        self.invoices      = {}

        self.completions = QStringListModel()

        self.tabs = tabs = QTabWidget(self)
        self.column_widths = self.config.get("column_widths_2", default_column_widths )
        tabs.addTab(self.create_history_tab(), _('History') )
        tabs.addTab(self.create_send_tab(), _('Send') )
        tabs.addTab(self.create_receive_tab(), _('Receive') )
        tabs.addTab(self.create_addresses_tab(), _('Addresses') )
        tabs.addTab(self.create_contacts_tab(), _('Contacts') )
        tabs.addTab(self.create_invoices_tab(), _('Invoices') )
        tabs.addTab(self.create_console_tab(), _('Console') )
        tabs.setMinimumSize(600, 400)
        tabs.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding)
        self.setCentralWidget(tabs)

        try:
            self.setGeometry(*self.config.get("winpos-qt"))
        except:
            self.setGeometry(100, 100, 840, 400)

        if self.config.get("is_maximized"):
            self.showMaximized()

        self.setWindowIcon(QIcon(":icons/electrum.png"))
        self.init_menubar()

        QShortcut(QKeySequence("Ctrl+W"), self, self.close)
        QShortcut(QKeySequence("Ctrl+Q"), self, self.close)
        QShortcut(QKeySequence("Ctrl+R"), self, self.update_wallet)
        QShortcut(QKeySequence("Ctrl+PgUp"), self, lambda: tabs.setCurrentIndex( (tabs.currentIndex() - 1 )%tabs.count() ))
        QShortcut(QKeySequence("Ctrl+PgDown"), self, lambda: tabs.setCurrentIndex( (tabs.currentIndex() + 1 )%tabs.count() ))

        for i in range(tabs.count()):
            QShortcut(QKeySequence("Alt+" + str(i + 1)), self, lambda i=i: tabs.setCurrentIndex(i))

        self.connect(self, QtCore.SIGNAL('update_status'), self.update_status)
        self.connect(self, QtCore.SIGNAL('banner_signal'), lambda: self.console.showMessage(self.network.banner) )
        self.connect(self, QtCore.SIGNAL('transaction_signal'), lambda: self.notify_transactions() )
        self.connect(self, QtCore.SIGNAL('payment_request_ok'), self.payment_request_ok)
        self.connect(self, QtCore.SIGNAL('payment_request_error'), self.payment_request_error)
        self.labelsChanged.connect(self.update_tabs)

        self.history_list.setFocus(True)

        # network callbacks
        if self.network:
            self.network.register_callback('updated', lambda: self.need_update.set())
            self.network.register_callback('banner', lambda: self.emit(QtCore.SIGNAL('banner_signal')))
            self.network.register_callback('status', lambda: self.emit(QtCore.SIGNAL('update_status')))
            self.network.register_callback('new_transaction', lambda: self.emit(QtCore.SIGNAL('transaction_signal')))
            self.network.register_callback('stop', self.close)

            # set initial message
            self.console.showMessage(self.network.banner)

        self.wallet = None
        self.payment_request = None
        self.qr_window = None
        self.not_enough_funds = False
        self.pluginsdialog = None

    def update_account_selector(self):
        # account selector
        accounts = self.wallet.get_account_names()
        self.account_selector.clear()
        if len(accounts) > 1:
            self.account_selector.addItems([_("All accounts")] + accounts.values())
            self.account_selector.setCurrentIndex(0)
            self.account_selector.show()
        else:
            self.account_selector.hide()

    def close_wallet(self):
        self.wallet.stop_threads()
        self.hide()
        run_hook('close_wallet')

    def load_wallet(self, wallet):
        import electrum
        self.wallet = wallet
        self.update_wallet_format()
        # address used to create a dummy transaction and estimate transaction fee
        a = self.wallet.addresses(False)
        self.dummy_address = a[0] if a else None

        self.invoices = self.wallet.storage.get('invoices', {})
        self.accounts_expanded = self.wallet.storage.get('accounts_expanded',{})
        self.current_account = self.wallet.storage.get("current_account", None)
        title = 'Electrum ' + self.wallet.electrum_version + '  -  ' + os.path.basename(self.wallet.storage.path)
        if self.wallet.is_watching_only(): title += ' [%s]' % (_('watching only'))
        self.setWindowTitle( title )
        self.update_history_tab()
        self.show()
        self.update_wallet()
        # Once GUI has been initialized check if we want to announce something since the callback has been called before the GUI was initialized
        self.notify_transactions()
        self.update_account_selector()
        # update menus
        self.new_account_menu.setEnabled(self.wallet.can_create_accounts())
        self.private_keys_menu.setEnabled(not self.wallet.is_watching_only())
        self.password_menu.setEnabled(self.wallet.can_change_password())
        self.seed_menu.setEnabled(self.wallet.has_seed())
        self.mpk_menu.setEnabled(self.wallet.is_deterministic())
        self.import_menu.setEnabled(self.wallet.can_import())
        self.export_menu.setEnabled(self.wallet.can_export())

        self.update_lock_icon()
        self.update_buttons_on_seed()
        self.update_console()

        self.clear_receive_tab()
        self.update_receive_tab()
        run_hook('load_wallet', wallet)


    def update_wallet_format(self):
        # convert old-format imported keys
        if self.wallet.imported_keys:
            password = self.password_dialog(_("Please enter your password in order to update imported keys"))
            try:
                self.wallet.convert_imported_keys(password)
            except:
                self.show_message("error")


    def open_wallet(self):
        wallet_folder = self.wallet.storage.path
        filename = unicode( QFileDialog.getOpenFileName(self, "Select your wallet file", wallet_folder) )
        if not filename:
            return
        try:
            storage = WalletStorage({'wallet_path': filename})
        except Exception as e:
            self.show_message(str(e))
            return
        if not storage.file_exists:
            self.show_message(_("File not found") + ' ' + filename)
            return
        # read wizard action
        try:
            wallet = Wallet(storage)
        except BaseException as e:
            QMessageBox.warning(None, _('Warning'), str(e), _('OK'))
            return
        action = wallet.get_action()
        # ask for confirmation
        if action is not None:
            if not self.question(_("This file contains an incompletely created wallet.\nDo you want to complete its creation now?")):
                return
        # close current wallet
        self.close_wallet()
        # run wizard
        if action is not None:
            import installwizard
            wizard = installwizard.InstallWizard(self.config, self.network, storage)
            try:
                wallet = wizard.run(action)
            except BaseException as e:
                traceback.print_exc(file=sys.stdout)
                QMessageBox.information(None, _('Error'), str(e), _('OK'))
                return
            if not wallet:
                return
        else:
            wallet.start_threads(self.network)
        # load new wallet in gui
        self.load_wallet(wallet)
        # save path
        self.config.set_key('default_wallet_path', filename)



    def backup_wallet(self):
        import shutil
        path = self.wallet.storage.path
        wallet_folder = os.path.dirname(path)
        filename = unicode( QFileDialog.getSaveFileName(self, _('Enter a filename for the copy of your wallet'), wallet_folder) )
        if not filename:
            return

        new_path = os.path.join(wallet_folder, filename)
        if new_path != path:
            try:
                shutil.copy2(path, new_path)
                QMessageBox.information(None,"Wallet backup created", _("A copy of your wallet file was created in")+" '%s'" % str(new_path))
            except (IOError, os.error), reason:
                QMessageBox.critical(None,"Unable to create backup", _("Electrum was unable to copy your wallet file to the specified location.")+"\n" + str(reason))


    def new_wallet(self):
        import installwizard

        wallet_folder = os.path.dirname(os.path.abspath(self.wallet.storage.path))
        i = 1
        while True:
            filename = "wallet_%d"%i
            if filename in os.listdir(wallet_folder):
                i += 1
            else:
                break

        filename = line_dialog(self, _('New Wallet'), _('Enter file name') + ':', _('OK'), filename)
        if not filename:
            return

        full_path = os.path.join(wallet_folder, filename)
        storage = WalletStorage({'wallet_path': full_path})
        if storage.file_exists:
            QMessageBox.critical(None, "Error", _("File exists"))
            return

        if self.wallet:
            self.close_wallet()
        wizard = installwizard.InstallWizard(self.config, self.network, storage)
        wallet = wizard.run('new')
        if wallet:
            self.load_wallet(wallet)



    def init_menubar(self):
        menubar = QMenuBar()

        file_menu = menubar.addMenu(_("&File"))
        file_menu.addAction(_("&Open"), self.open_wallet).setShortcut(QKeySequence.Open)
        file_menu.addAction(_("&New/Restore"), self.new_wallet).setShortcut(QKeySequence.New)
        file_menu.addAction(_("&Save Copy"), self.backup_wallet).setShortcut(QKeySequence.SaveAs)
        file_menu.addAction(_("&Quit"), self.close)

        wallet_menu = menubar.addMenu(_("&Wallet"))
        wallet_menu.addAction(_("&New contact"), self.new_contact_dialog)
        self.new_account_menu = wallet_menu.addAction(_("&New account"), self.new_account_dialog)

        wallet_menu.addSeparator()

        self.password_menu = wallet_menu.addAction(_("&Password"), self.change_password_dialog)
        self.seed_menu = wallet_menu.addAction(_("&Seed"), self.show_seed_dialog)
        self.mpk_menu = wallet_menu.addAction(_("&Master Public Keys"), self.show_master_public_keys)

        wallet_menu.addSeparator()
        labels_menu = wallet_menu.addMenu(_("&Labels"))
        labels_menu.addAction(_("&Import"), self.do_import_labels)
        labels_menu.addAction(_("&Export"), self.do_export_labels)

        self.private_keys_menu = wallet_menu.addMenu(_("&Private keys"))
        self.private_keys_menu.addAction(_("&Sweep"), self.sweep_key_dialog)
        self.import_menu = self.private_keys_menu.addAction(_("&Import"), self.do_import_privkey)
        self.export_menu = self.private_keys_menu.addAction(_("&Export"), self.export_privkeys_dialog)
        wallet_menu.addAction(_("&Export History"), self.export_history_dialog)

        tools_menu = menubar.addMenu(_("&Tools"))

        # Settings / Preferences are all reserved keywords in OSX using this as work around
        tools_menu.addAction(_("Electrum preferences") if sys.platform == 'darwin' else _("Preferences"), self.settings_dialog)
        tools_menu.addAction(_("&Network"), self.run_network_dialog)
        tools_menu.addAction(_("&Plugins"), self.plugins_dialog)
        tools_menu.addSeparator()
        tools_menu.addAction(_("&Sign/verify message"), self.sign_verify_message)
        tools_menu.addAction(_("&Encrypt/decrypt message"), self.encrypt_message)
        tools_menu.addSeparator()

        csv_transaction_menu = tools_menu.addMenu(_("&Create transaction"))
        csv_transaction_menu.addAction(_("&From CSV file"), self.do_process_from_csv_file)
        csv_transaction_menu.addAction(_("&From CSV text"), self.do_process_from_csv_text)

        raw_transaction_menu = tools_menu.addMenu(_("&Load transaction"))
        raw_transaction_menu.addAction(_("&From file"), self.do_process_from_file)
        raw_transaction_menu.addAction(_("&From text"), self.do_process_from_text)
        raw_transaction_menu.addAction(_("&From the blockchain"), self.do_process_from_txid)
        raw_transaction_menu.addAction(_("&From QR code"), self.read_tx_from_qrcode)
        self.raw_transaction_menu = raw_transaction_menu

        help_menu = menubar.addMenu(_("&Help"))
        help_menu.addAction(_("&About"), self.show_about)
        help_menu.addAction(_("&Official website"), lambda: webbrowser.open("http://electrum.org"))
        help_menu.addSeparator()
        help_menu.addAction(_("&Documentation"), lambda: webbrowser.open("http://electrum.orain.org/")).setShortcut(QKeySequence.HelpContents)
        help_menu.addAction(_("&Report Bug"), self.show_report_bug)

        self.setMenuBar(menubar)

    def show_about(self):
        QMessageBox.about(self, "Electrum",
            _("Version")+" %s" % (self.wallet.electrum_version) + "\n\n" + _("Electrum's focus is speed, with low resource usage and simplifying Bitcoin. You do not need to perform regular backups, because your wallet can be recovered from a secret phrase that you can memorize or write on paper. Startup times are instant because it operates in conjunction with high-performance servers that handle the most complicated parts of the Bitcoin system."))

    def show_report_bug(self):
        QMessageBox.information(self, "Electrum - " + _("Reporting Bugs"),
            _("Please report any bugs as issues on github:")+" <a href=\"https://github.com/spesmilo/electrum/issues\">https://github.com/spesmilo/electrum/issues</a>")


    def notify_transactions(self):
        if not self.network or not self.network.is_connected():
            return

        print_error("Notifying GUI")
        if len(self.network.pending_transactions_for_notifications) > 0:
            # Combine the transactions if there are more then three
            tx_amount = len(self.network.pending_transactions_for_notifications)
            if(tx_amount >= 3):
                total_amount = 0
                for tx in self.network.pending_transactions_for_notifications:
                    is_relevant, is_mine, v, fee = self.wallet.get_tx_value(tx)
                    if(v > 0):
                        total_amount += v

                self.notify(_("%(txs)s new transactions received. Total amount received in the new transactions %(amount)s %(unit)s") \
                                % { 'txs' : tx_amount, 'amount' : self.format_amount(total_amount), 'unit' : self.base_unit()})

                self.network.pending_transactions_for_notifications = []
            else:
              for tx in self.network.pending_transactions_for_notifications:
                  if tx:
                      self.network.pending_transactions_for_notifications.remove(tx)
                      is_relevant, is_mine, v, fee = self.wallet.get_tx_value(tx)
                      if(v > 0):
                          self.notify(_("New transaction received. %(amount)s %(unit)s") % { 'amount' : self.format_amount(v), 'unit' : self.base_unit()})

    def notify(self, message):
        if self.tray:
            self.tray.showMessage("Electrum", message, QSystemTrayIcon.Information, 20000)



    # custom wrappers for getOpenFileName and getSaveFileName, that remember the path selected by the user
    def getOpenFileName(self, title, filter = ""):
        directory = self.config.get('io_dir', unicode(os.path.expanduser('~')))
        fileName = unicode( QFileDialog.getOpenFileName(self, title, directory, filter) )
        if fileName and directory != os.path.dirname(fileName):
            self.config.set_key('io_dir', os.path.dirname(fileName), True)
        return fileName

    def getSaveFileName(self, title, filename, filter = ""):
        directory = self.config.get('io_dir', unicode(os.path.expanduser('~')))
        path = os.path.join( directory, filename )
        fileName = unicode( QFileDialog.getSaveFileName(self, title, path, filter) )
        if fileName and directory != os.path.dirname(fileName):
            self.config.set_key('io_dir', os.path.dirname(fileName), True)
        return fileName

    def close(self):
        if self.qr_window:
            self.qr_window.close()
        QMainWindow.close(self)
        run_hook('close_main_window')

    def connect_slots(self, sender):
        self.connect(sender, QtCore.SIGNAL('timersignal'), self.timer_actions)
        self.previous_payto_e=''

    def timer_actions(self):
        if self.need_update.is_set():
            self.update_wallet()
            self.need_update.clear()

        run_hook('timer_actions')

    def format_amount(self, x, is_diff=False, whitespaces=False):
        return format_satoshis(x, is_diff, self.num_zeros, self.decimal_point, whitespaces)


    def get_decimal_point(self):
        return self.decimal_point


    def base_unit(self):
        assert self.decimal_point in [2, 5, 8]
        if self.decimal_point == 2:
            return 'bits'
        if self.decimal_point == 5:
            return 'mBTC'
        if self.decimal_point == 8:
            return 'BTC'
        raise Exception('Unknown base unit')

    def update_status(self):
        if not self.wallet:
            return

        if self.network is None or not self.network.is_running():
            text = _("Offline")
            icon = QIcon(":icons/status_disconnected.png")

        elif self.network.is_connected():
            server_lag = self.network.get_local_height() - self.network.get_server_height()
            if not self.wallet.up_to_date:
                text = _("Synchronizing...")
                icon = QIcon(":icons/status_waiting.png")
            elif server_lag > 1:
                text = _("Server is lagging (%d blocks)"%server_lag)
                icon = QIcon(":icons/status_lagging.png")
            else:
                c, u = self.wallet.get_account_balance(self.current_account)
                text =  _( "Balance" ) + ": %s "%( self.format_amount(c) ) + self.base_unit()
                if u: text +=  " [%s unconfirmed]"%( self.format_amount(u,True).strip() )

                # append fiat balance and price from exchange rate plugin
                r = {}
                run_hook('get_fiat_status_text', c+u, r)
                quote = r.get(0)
                if quote:
                    text += "%s"%quote

                if self.tray:
                    self.tray.setToolTip(text)
                icon = QIcon(":icons/status_connected.png")
        else:
            text = _("Not connected")
            icon = QIcon(":icons/status_disconnected.png")

        self.balance_label.setText(text)
        self.status_button.setIcon( icon )


    def update_wallet(self):
        self.update_status()
        if self.wallet.up_to_date or not self.network or not self.network.is_connected():
            self.update_tabs()

    def update_tabs(self):
        self.update_history_tab()
        self.update_receive_tab()
        self.update_address_tab()
        self.update_contacts_tab()
        self.update_completions()
        self.update_invoices_tab()


    def create_history_tab(self):
        self.history_list = l = MyTreeWidget(self)
        l.setColumnCount(5)
        for i,width in enumerate(self.column_widths['history']):
            l.setColumnWidth(i, width)
        l.setHeaderLabels( [ '', _('Date'), _('Description') , _('Amount'), _('Balance')] )
        l.itemDoubleClicked.connect(self.tx_label_clicked)
        l.itemChanged.connect(self.tx_label_changed)
        l.customContextMenuRequested.connect(self.create_history_menu)
        return l


    def create_history_menu(self, position):
        self.history_list.selectedIndexes()
        item = self.history_list.currentItem()
        be = self.config.get('block_explorer', 'Blockchain.info')
        if be == 'Blockchain.info':
            block_explorer = 'https://blockchain.info/tx/'
        elif be == 'Blockr.io':
            block_explorer = 'https://blockr.io/tx/info/'
        elif be == 'Insight.is':
            block_explorer = 'http://live.insight.is/tx/'
        elif be == "Blocktrail.com":
            block_explorer = 'https://www.blocktrail.com/BTC/tx/'

        if not item: return
        tx_hash = str(item.data(0, Qt.UserRole).toString())
        if not tx_hash: return
        menu = QMenu()
        menu.addAction(_("Copy ID to Clipboard"), lambda: self.app.clipboard().setText(tx_hash))
        menu.addAction(_("Details"), lambda: self.show_transaction(self.wallet.transactions.get(tx_hash)))
        menu.addAction(_("Edit description"), lambda: self.tx_label_clicked(item,2))
        menu.addAction(_("View on block explorer"), lambda: webbrowser.open(block_explorer + tx_hash))
        menu.exec_(self.contacts_list.viewport().mapToGlobal(position))


    def show_transaction(self, tx):
        import transaction_dialog
        d = transaction_dialog.TxDialog(tx, self)
        d.exec_()

    def tx_label_clicked(self, item, column):
        if column==2 and item.isSelected():
            self.is_edit=True
            item.setFlags(Qt.ItemIsEditable|Qt.ItemIsSelectable | Qt.ItemIsUserCheckable | Qt.ItemIsEnabled | Qt.ItemIsDragEnabled)
            self.history_list.editItem( item, column )
            item.setFlags(Qt.ItemIsSelectable | Qt.ItemIsUserCheckable | Qt.ItemIsEnabled | Qt.ItemIsDragEnabled)
            self.is_edit=False

    def tx_label_changed(self, item, column):
        if self.is_edit:
            return
        self.is_edit=True
        tx_hash = str(item.data(0, Qt.UserRole).toString())
        tx = self.wallet.transactions.get(tx_hash)
        text = unicode( item.text(2) )
        self.wallet.set_label(tx_hash, text)
        if text:
            item.setForeground(2, QBrush(QColor('black')))
        else:
            text = self.wallet.get_default_label(tx_hash)
            item.setText(2, text)
            item.setForeground(2, QBrush(QColor('gray')))
        self.is_edit=False


    def edit_label(self, is_recv):
        l = self.address_list if is_recv else self.contacts_list
        item = l.currentItem()
        item.setFlags(Qt.ItemIsEditable|Qt.ItemIsSelectable | Qt.ItemIsUserCheckable | Qt.ItemIsEnabled | Qt.ItemIsDragEnabled)
        l.editItem( item, 1 )
        item.setFlags(Qt.ItemIsSelectable | Qt.ItemIsUserCheckable | Qt.ItemIsEnabled | Qt.ItemIsDragEnabled)



    def address_label_clicked(self, item, column, l, column_addr, column_label):
        if column == column_label and item.isSelected():
            is_editable = item.data(0, 32).toBool()
            if not is_editable:
                return
            addr = unicode( item.text(column_addr) )
            label = unicode( item.text(column_label) )
            item.setFlags(Qt.ItemIsEditable|Qt.ItemIsSelectable | Qt.ItemIsUserCheckable | Qt.ItemIsEnabled | Qt.ItemIsDragEnabled)
            l.editItem( item, column )
            item.setFlags(Qt.ItemIsSelectable | Qt.ItemIsUserCheckable | Qt.ItemIsEnabled | Qt.ItemIsDragEnabled)


    def address_label_changed(self, item, column, l, column_addr, column_label):
        if column == column_label:
            addr = unicode( item.text(column_addr) )
            text = unicode( item.text(column_label) )
            is_editable = item.data(0, 32).toBool()
            if not is_editable:
                return

            changed = self.wallet.set_label(addr, text)
            if changed:
                self.update_history_tab()
                self.update_completions()

            self.current_item_changed(item)

        run_hook('item_changed', item, column)


    def current_item_changed(self, a):
        run_hook('current_item_changed', a)


    def format_time(self, timestamp):
        try:
            time_str = datetime.datetime.fromtimestamp( timestamp).isoformat(' ')[:-3]
        except Exception:
            time_str = _("error")
        return time_str


    def update_history_tab(self):

        self.history_list.clear()
        for item in self.wallet.get_tx_history(self.current_account):
            tx_hash, conf, is_mine, value, fee, balance, timestamp = item
            time_str = _("unknown")
            if conf > 0:
                time_str = self.format_time(timestamp)
            if conf == -1:
                time_str = 'unverified'
                icon = QIcon(":icons/unconfirmed.png")
            elif conf == 0:
                time_str = 'pending'
                icon = QIcon(":icons/unconfirmed.png")
            elif conf < 6:
                icon = QIcon(":icons/clock%d.png"%conf)
            else:
                icon = QIcon(":icons/confirmed.png")

            if value is not None:
                v_str = self.format_amount(value, True, whitespaces=True)
            else:
                v_str = '--'

            balance_str = self.format_amount(balance, whitespaces=True)

            if tx_hash:
                label, is_default_label = self.wallet.get_label(tx_hash)
            else:
                label = _('Pruned transaction outputs')
                is_default_label = False

            item = QTreeWidgetItem( [ '', time_str, label, v_str, balance_str] )
            item.setFont(2, QFont(MONOSPACE_FONT))
            item.setFont(3, QFont(MONOSPACE_FONT))
            item.setFont(4, QFont(MONOSPACE_FONT))
            if value < 0:
                item.setForeground(3, QBrush(QColor("#BC1E1E")))
            if tx_hash:
                item.setData(0, Qt.UserRole, tx_hash)
                item.setToolTip(0, "%d %s\nTxId:%s" % (conf, _('Confirmations'), tx_hash) )
            if is_default_label:
                item.setForeground(2, QBrush(QColor('grey')))

            item.setIcon(0, icon)
            self.history_list.insertTopLevelItem(0,item)


        self.history_list.setCurrentItem(self.history_list.topLevelItem(0))
        run_hook('history_tab_update')


    def create_receive_tab(self):
        w = QWidget()
        grid = QGridLayout(w)
        grid.setColumnMinimumWidth(3, 300)
        grid.setColumnStretch(5, 1)

        self.receive_address_e = QLineEdit()
        self.receive_address_e.setReadOnly(True)
        grid.addWidget(QLabel(_('Receiving address')), 0, 0)
        grid.addWidget(self.receive_address_e, 0, 1, 1, 3)
        self.receive_address_e.textChanged.connect(self.update_receive_qr)

        self.copy_button = QPushButton()
        self.copy_button.setIcon(QIcon(":icons/copy.png"))
        self.copy_button.clicked.connect(lambda: self.app.clipboard().setText(self.receive_address_e.text()))
        grid.addWidget(self.copy_button, 0, 4)

        self.receive_message_e = QLineEdit()
        grid.addWidget(QLabel(_('Message')), 1, 0)
        grid.addWidget(self.receive_message_e, 1, 1, 1, 3)
        self.receive_message_e.textChanged.connect(self.update_receive_qr)

        self.receive_amount_e = BTCAmountEdit(self.get_decimal_point)
        grid.addWidget(QLabel(_('Requested amount')), 2, 0)
        grid.addWidget(self.receive_amount_e, 2, 1, 1, 2)
        self.receive_amount_e.textChanged.connect(self.update_receive_qr)

        self.save_request_button = QPushButton(_('Save'))
        self.save_request_button.clicked.connect(self.save_payment_request)
        grid.addWidget(self.save_request_button, 3, 1)

        clear_button = QPushButton(_('New'))
        clear_button.clicked.connect(self.new_receive_address)
        grid.addWidget(clear_button, 3, 2)
        grid.setRowStretch(4, 1)

        self.receive_qr = QRCodeWidget(fixedSize=200)
        grid.addWidget(self.receive_qr, 0, 5, 5, 2)
        self.receive_qr.mousePressEvent = lambda x: self.toggle_qr_window()

        grid.setRowStretch(5, 1)

        self.receive_requests_label = QLabel(_('Saved Requests'))
        self.receive_list = MyTreeWidget(self)
        self.receive_list.customContextMenuRequested.connect(self.receive_list_menu)
        self.receive_list.currentItemChanged.connect(self.receive_item_changed)
        self.receive_list.itemClicked.connect(self.receive_item_changed)
        self.receive_list.setHeaderLabels( [_('Date'), _('Account'), _('Address'), _('Message'), _('Amount')] )
        self.receive_list.setSortingEnabled(True)
        self.receive_list.setColumnWidth(0, 180)
        self.receive_list.hideColumn(1)     # the update will show it if necessary
        self.receive_list.setColumnWidth(2, 340)
        h = self.receive_list.header()
        h.setStretchLastSection(False)
        h.setResizeMode(3, QHeaderView.Stretch)
        grid.addWidget(self.receive_requests_label, 6, 0)
        grid.addWidget(self.receive_list, 7, 0, 1, 6)
        return w

    def receive_item_changed(self, item):
        if item is None:
            return
        addr = str(item.text(2))
        req = self.receive_requests[addr]
        time, amount, message = req['time'], req['amount'], req['msg']
        self.receive_address_e.setText(addr)
        self.receive_message_e.setText(message)
        self.receive_amount_e.setAmount(amount)


    def receive_list_delete(self, item):
        addr = str(item.text(2))
        self.receive_requests.pop(addr)
        self.wallet.storage.put('receive_requests2', self.receive_requests)
        self.update_receive_tab()
        self.clear_receive_tab()

    def receive_list_menu(self, position):
        item = self.receive_list.itemAt(position)
        menu = QMenu()
        menu.addAction(_("Copy to clipboard"), lambda: self.app.clipboard().setText(str(item.text(2))))
        menu.addAction(_("Delete"), lambda: self.receive_list_delete(item))
        menu.exec_(self.receive_list.viewport().mapToGlobal(position))

    def save_payment_request(self):
        timestamp = int(time.time())
        addr = str(self.receive_address_e.text())
        amount = self.receive_amount_e.get_amount()
        message = unicode(self.receive_message_e.text())
        if not message and not amount:
            QMessageBox.warning(self, _('Error'), _('No message or amount'), _('OK'))
            return
        self.receive_requests = self.wallet.storage.get('receive_requests2',{})
        self.receive_requests[addr] = {'time':timestamp, 'amount':amount, 'msg':message}
        self.wallet.storage.put('receive_requests2', self.receive_requests)
        self.update_receive_tab()

    def get_receive_address(self):
        domain = self.wallet.get_account_addresses(self.current_account, include_change=False)
        for addr in domain:
            if not self.wallet.history.get(addr) and addr not in self.receive_requests.keys():
                return addr

    def new_receive_address(self):
        addr = self.get_receive_address()
        if addr is None:
            if isinstance(self.wallet, Imported_Wallet):
                self.show_message(_('No more addresses in your wallet.'))
                return
            if not self.question(_("Warning: The next address will not be recovered automatically if you restore your wallet from seed; you may need to add it manually.\n\nThis occurs because you have too many unused addresses in your wallet. To avoid this situation, use the existing addresses first.\n\nCreate anyway?")):
                return
            addr = self.wallet.create_new_address(self.current_account, False)
        self.set_receive_address(addr)

    def set_receive_address(self, addr):
        self.receive_address_e.setText(addr)
        self.receive_message_e.setText('')
        self.receive_amount_e.setAmount(None)

    def clear_receive_tab(self):
        self.receive_requests = self.wallet.storage.get('receive_requests2',{})
        domain = self.wallet.get_account_addresses(self.current_account, include_change=False)
        for addr in domain:
            if not self.wallet.history.get(addr) and addr not in self.receive_requests.keys():
                break
        else:
            addr = ''
        self.receive_address_e.setText(addr)
        self.receive_message_e.setText('')
        self.receive_amount_e.setAmount(None)

    def toggle_qr_window(self):
        import qrwindow
        if not self.qr_window:
            self.qr_window = qrwindow.QR_Window(self)
            self.qr_window.setVisible(True)
            self.qr_window_geometry = self.qr_window.geometry()
        else:
            if not self.qr_window.isVisible():
                self.qr_window.setVisible(True)
                self.qr_window.setGeometry(self.qr_window_geometry)
            else:
                self.qr_window_geometry = self.qr_window.geometry()
                self.qr_window.setVisible(False)
        self.update_receive_qr()


    def receive_at(self, addr):
        if not bitcoin.is_address(addr):
            return
        self.tabs.setCurrentIndex(2)
        self.receive_address_e.setText(addr)

    def update_receive_tab(self):
        self.receive_requests = self.wallet.storage.get('receive_requests2',{})

        # hide receive tab if no receive requests available
        b = len(self.receive_requests) > 0
        self.receive_list.setVisible(b)
        self.receive_requests_label.setVisible(b)

        # check if it is necessary to show the account
        self.receive_list.setColumnHidden(1, len(self.wallet.get_accounts()) == 1)

        # update the receive address if necessary
        current_address = self.receive_address_e.text()
        domain = self.wallet.get_account_addresses(self.current_account, include_change=False)
        if not current_address in domain:
            addr = self.get_receive_address()
            if addr:
                self.set_receive_address(addr)

        # clear the list and fill it again
        self.receive_list.clear()
        for address, req in self.receive_requests.viewitems():
            timestamp, amount, message = req['time'], req['amount'], req['msg']
            # only show requests for the current account
            if address not in domain:
                continue
            date = self.format_time(timestamp)
            account = self.wallet.get_account_name(self.wallet.get_account_from_address(address))
            item = QTreeWidgetItem( [ date, account, address, message, self.format_amount(amount) if amount else ""])
            item.setFont(2, QFont(MONOSPACE_FONT))
            self.receive_list.addTopLevelItem(item)



    def update_receive_qr(self):
        import urlparse, urllib
        addr = str(self.receive_address_e.text())
        amount = self.receive_amount_e.get_amount()
        message = unicode(self.receive_message_e.text()).encode('utf8')
        self.save_request_button.setEnabled((amount is not None) or (message != ""))
        if addr:
            query = []
            if amount:
                query.append('amount=%s'%format_satoshis(amount))
            if message:
                query.append('message=%s'%urllib.quote(message))
            p = urlparse.ParseResult(scheme='bitcoin', netloc='', path=addr, params='', query='&'.join(query), fragment='')
            url = urlparse.urlunparse(p)
        else:
            url = ""
        self.receive_qr.setData(url)
        if self.qr_window:
            self.qr_window.set_content(addr, amount, message, url)


    def create_send_tab(self):
        w = QWidget()

        self.send_grid = grid = QGridLayout(w)
        grid.setSpacing(8)
        grid.setColumnMinimumWidth(3,300)
        grid.setColumnStretch(5,1)
        grid.setRowStretch(8, 1)

        from paytoedit import PayToEdit
        self.amount_e = BTCAmountEdit(self.get_decimal_point)
        self.payto_e = PayToEdit(self)
        self.payto_help = HelpButton(_('Recipient of the funds.') + '\n\n' + _('You may enter a Bitcoin address, a label from your list of contacts (a list of completions will be proposed), or an alias (email-like address that forwards to a Bitcoin address)'))
        grid.addWidget(QLabel(_('Pay to')), 1, 0)
        grid.addWidget(self.payto_e, 1, 1, 1, 3)
        grid.addWidget(self.payto_help, 1, 4)

        completer = QCompleter()
        completer.setCaseSensitivity(False)
        self.payto_e.setCompleter(completer)
        completer.setModel(self.completions)

        self.message_e = MyLineEdit()
        self.message_help = HelpButton(_('Description of the transaction (not mandatory).') + '\n\n' + _('The description is not sent to the recipient of the funds. It is stored in your wallet file, and displayed in the \'History\' tab.'))
        grid.addWidget(QLabel(_('Description')), 2, 0)
        grid.addWidget(self.message_e, 2, 1, 1, 3)
        grid.addWidget(self.message_help, 2, 4)

        self.from_label = QLabel(_('From'))
        grid.addWidget(self.from_label, 3, 0)
        self.from_list = MyTreeWidget(self)
        self.from_list.setColumnCount(2)
        self.from_list.setColumnWidth(0, 350)
        self.from_list.setColumnWidth(1, 50)
        self.from_list.setHeaderHidden(True)
        self.from_list.setMaximumHeight(80)
        self.from_list.setContextMenuPolicy(Qt.CustomContextMenu)
        self.from_list.customContextMenuRequested.connect(self.from_list_menu)
        grid.addWidget(self.from_list, 3, 1, 1, 3)
        self.set_pay_from([])

        self.amount_help = HelpButton(_('Amount to be sent.') + '\n\n' \
                                      + _('The amount will be displayed in red if you do not have enough funds in your wallet. Note that if you have frozen some of your addresses, the available funds will be lower than your total balance.') \
                                      + '\n\n' + _('Keyboard shortcut: type "!" to send all your coins.'))
        grid.addWidget(QLabel(_('Amount')), 4, 0)
        grid.addWidget(self.amount_e, 4, 1, 1, 2)
        grid.addWidget(self.amount_help, 4, 3)

        self.fee_e_label = QLabel(_('Fee'))
        self.fee_e = BTCAmountEdit(self.get_decimal_point)
        grid.addWidget(self.fee_e_label, 5, 0)
        grid.addWidget(self.fee_e, 5, 1, 1, 2)
        msg = _('Bitcoin transactions are in general not free. A transaction fee is paid by the sender of the funds.') + '\n\n'\
              + _('The amount of fee can be decided freely by the sender. However, transactions with low fees take more time to be processed.') + '\n\n'\
              + _('A suggested fee is automatically added to this field. You may override it. The suggested fee increases with the size of the transaction.')
        self.fee_e_help = HelpButton(msg)
        grid.addWidget(self.fee_e_help, 5, 3)
        self.update_fee_edit()
        self.send_button = EnterButton(_("Send"), self.do_send)
        grid.addWidget(self.send_button, 6, 1)
        b = EnterButton(_("Clear"), self.do_clear)
        grid.addWidget(b, 6, 2)
        self.payto_sig = QLabel('')
        grid.addWidget(self.payto_sig, 7, 0, 1, 4)
        w.setLayout(grid)

        def on_shortcut():
            sendable = self.get_sendable_balance()
            inputs = self.get_coins()
            for i in inputs: self.wallet.add_input_info(i)
            addr = self.payto_e.payto_address if self.payto_e.payto_address else self.dummy_address
            output = ('address', addr, sendable)
            dummy_tx = Transaction(inputs, [output])
            fee = self.wallet.estimated_fee(dummy_tx)
            self.amount_e.setAmount(max(0,sendable-fee))
            self.amount_e.textEdited.emit("")
            self.fee_e.setAmount(fee)

        self.amount_e.shortcut.connect(on_shortcut)

        def text_edited(is_fee):
            outputs = self.payto_e.get_outputs()
            amount = self.amount_e.get_amount()
            fee = self.fee_e.get_amount() if is_fee else None
            if amount is None:
                self.fee_e.setAmount(None)
                self.not_enough_funds = False
            else:
                if not outputs:
                    addr = self.payto_e.payto_address if self.payto_e.payto_address else self.dummy_address
                    outputs = [('address', addr, amount)]
                try:
                    tx = self.wallet.make_unsigned_transaction(outputs, fee, coins = self.get_coins())
                    self.not_enough_funds = False
                except NotEnoughFunds:
                    self.not_enough_funds = True
                if not is_fee:
                    fee = None if self.not_enough_funds else self.wallet.get_tx_fee(tx)
                    self.fee_e.setAmount(fee)

        self.payto_e.textChanged.connect(lambda:text_edited(False))
        self.amount_e.textEdited.connect(lambda:text_edited(False))
        self.fee_e.textEdited.connect(lambda:text_edited(True))

        def entry_changed():
            if not self.not_enough_funds:
                palette = QPalette()
                palette.setColor(self.amount_e.foregroundRole(), QColor('black'))
                text = ""
            else:
                palette = QPalette()
                palette.setColor(self.amount_e.foregroundRole(), QColor('red'))
                text = _( "Not enough funds" )
                c, u = self.wallet.get_frozen_balance()
                if c+u: text += ' (' + self.format_amount(c+u).strip() + ' ' + self.base_unit() + ' ' +_("are frozen") + ')'
            self.statusBar().showMessage(text)
            self.amount_e.setPalette(palette)
            self.fee_e.setPalette(palette)

        self.amount_e.textChanged.connect(entry_changed)
        self.fee_e.textChanged.connect(entry_changed)

        run_hook('create_send_tab', grid)
        return w

    def update_fee_edit(self):
        b = self.config.get('can_edit_fees', False)
        self.fee_e.setVisible(b)
        self.fee_e_label.setVisible(b)
        self.fee_e_help.setVisible(b)

    def from_list_delete(self, item):
        i = self.from_list.indexOfTopLevelItem(item)
        self.pay_from.pop(i)
        self.redraw_from_list()

    def from_list_menu(self, position):
        item = self.from_list.itemAt(position)
        menu = QMenu()
        menu.addAction(_("Remove"), lambda: self.from_list_delete(item))
        menu.exec_(self.from_list.viewport().mapToGlobal(position))

    def set_pay_from(self, domain = None):
        self.pay_from = [] if domain == [] else self.wallet.get_unspent_coins(domain)
        self.redraw_from_list()

    def redraw_from_list(self):
        self.from_list.clear()
        self.from_label.setHidden(len(self.pay_from) == 0)
        self.from_list.setHidden(len(self.pay_from) == 0)

        def format(x):
            h = x.get('prevout_hash')
            return h[0:8] + '...' + h[-8:] + ":%d"%x.get('prevout_n') + u'\t' + "%s"%x.get('address')

        for item in self.pay_from:
            self.from_list.addTopLevelItem(QTreeWidgetItem( [format(item), self.format_amount(item['value']) ]))

    def update_completions(self):
        l = []
        for addr,label in self.wallet.labels.items():
            if addr in self.wallet.addressbook:
                l.append( label + '  <' + addr + '>')

        run_hook('update_completions', l)
        self.completions.setStringList(l)


    def protected(func):
        return lambda s, *args: s.do_protect(func, args)


    def read_send_tab(self):

        if self.payment_request and self.payment_request.has_expired():
            QMessageBox.warning(self, _('Error'), _('Payment request has expired'), _('OK'))
            return

        label = unicode( self.message_e.text() )

        if self.payment_request:
            outputs = self.payment_request.get_outputs()
        else:
            errors = self.payto_e.get_errors()
            if errors:
                self.show_warning(_("Invalid Lines found:") + "\n\n" + '\n'.join([ _("Line #") + str(x[0]+1) + ": " + x[1] for x in errors]))
                return
            outputs = self.payto_e.get_outputs()

        if not outputs:
            QMessageBox.warning(self, _('Error'), _('No outputs'), _('OK'))
            return

        for _type, addr, amount in outputs:
            if addr is None:
                QMessageBox.warning(self, _('Error'), _('Bitcoin Address is None'), _('OK'))
                return
            if _type == 'address' and not bitcoin.is_address(addr):
                QMessageBox.warning(self, _('Error'), _('Invalid Bitcoin Address'), _('OK'))
                return
            if amount is None:
                QMessageBox.warning(self, _('Error'), _('Invalid Amount'), _('OK'))
                return

        fee = self.fee_e.get_amount()
        if fee is None:
            QMessageBox.warning(self, _('Error'), _('Invalid Fee'), _('OK'))
            return

        amount = sum(map(lambda x:x[2], outputs))
        confirm_amount = self.config.get('confirm_amount', 100000000)
        if amount >= confirm_amount:
            o = '\n'.join(map(lambda x:x[1], outputs))
            if not self.question(_("send %(amount)s to %(address)s?")%{ 'amount' : self.format_amount(amount) + ' '+ self.base_unit(), 'address' : o}):
                return

        coins = self.get_coins()
        return outputs, fee, label, coins


    def do_send(self):
        if run_hook('before_send'):
            return
        r = self.read_send_tab()
        if not r:
            return
        outputs, fee, label, coins = r
        try:
            tx = self.wallet.make_unsigned_transaction(outputs, fee, None, coins = coins)
            if not tx:
                raise BaseException(_("Insufficient funds"))
        except Exception as e:
            traceback.print_exc(file=sys.stdout)
            self.show_message(str(e))
            return

        if tx.get_fee() < MIN_RELAY_TX_FEE and tx.requires_fee(self.wallet.verifier):
            QMessageBox.warning(self, _('Error'), _("This transaction requires a higher fee, or it will not be propagated by the network."), _('OK'))
            return

        if not self.config.get('can_edit_fees', False):
            if not self.question(_("A fee of %(fee)s will be added to this transaction.\nProceed?")%{ 'fee' : self.format_amount(fee) + ' '+ self.base_unit()}):
                return
        else:
            confirm_fee = self.config.get('confirm_fee', 100000)
            if fee >= confirm_fee:
                if not self.question(_("The fee for this transaction seems unusually high.\nAre you really sure you want to pay %(fee)s in fees?")%{ 'fee' : self.format_amount(fee) + ' '+ self.base_unit()}):
                    return

        self.send_tx(tx, label)


    @protected
    def send_tx(self, tx, label, password):
        self.send_button.setDisabled(True)

        # call hook to see if plugin needs gui interaction
        run_hook('send_tx', tx)

        # sign the tx
        def sign_thread():
            if self.wallet.is_watching_only():
                return tx
            self.wallet.sign_transaction(tx, password)
            return tx

        def sign_done(tx):
            if not tx.is_complete() or self.config.get('show_before_broadcast'):
                self.show_transaction(tx)
                self.do_clear()
                return
            if label:
                self.wallet.set_label(tx.hash(), label)
            self.broadcast_transaction(tx)

        # keep a reference to WaitingDialog or the gui might crash
        self.waiting_dialog = WaitingDialog(self, 'Signing..', sign_thread, sign_done, lambda: self.send_button.setDisabled(False))
        self.waiting_dialog.start()



    def broadcast_transaction(self, tx):

        def broadcast_thread():
            # non-GUI thread
            pr = self.payment_request
            if pr is None:
                return self.wallet.sendtx(tx)
            if pr.has_expired():
                self.payment_request = None
                return False, _("Payment request has expired")
            status, msg =  self.wallet.sendtx(tx)
            if not status:
                return False, msg
            self.invoices[pr.get_id()] = (pr.get_domain(), pr.get_memo(), pr.get_amount(), pr.get_expiration_date(), PR_PAID, tx.hash())
            self.wallet.storage.put('invoices', self.invoices)
            self.payment_request = None
            refund_address = self.wallet.addresses()[0]
            ack_status, ack_msg = pr.send_ack(str(tx), refund_address)
            if ack_status:
                msg = ack_msg
            return status, msg

        def broadcast_done(status, msg):
            # GUI thread
            if status:
                QMessageBox.information(self, '', _('Payment sent.') + '\n' + msg, _('OK'))
                self.update_invoices_tab()
                self.do_clear()
            else:
                QMessageBox.warning(self, _('Error'), msg, _('OK'))
            self.send_button.setDisabled(False)

        self.waiting_dialog = WaitingDialog(self, 'Broadcasting..', broadcast_thread, broadcast_done)
        self.waiting_dialog.start()



    def prepare_for_payment_request(self):
        self.tabs.setCurrentIndex(1)
        self.payto_e.is_pr = True
        for e in [self.payto_e, self.amount_e, self.message_e]:
            e.setFrozen(True)
        for h in [self.payto_help, self.amount_help, self.message_help]:
            h.hide()
        self.payto_e.setText(_("please wait..."))
        return True

    def payment_request_ok(self):
        pr = self.payment_request
        pr_id = pr.get_id()
        if pr_id not in self.invoices:
            self.invoices[pr_id] = (pr.get_domain(), pr.get_memo(), pr.get_amount(), pr.get_expiration_date(), PR_UNPAID, None)
            self.wallet.storage.put('invoices', self.invoices)
            self.update_invoices_tab()
        else:
            print_error('invoice already in list')

        status = self.invoices[pr_id][4]
        if status == PR_PAID:
            self.do_clear()
            self.show_message("invoice already paid")
            self.payment_request = None
            return

        self.payto_help.show()
        self.payto_help.set_alt(lambda: self.show_pr_details(pr))

        if not pr.has_expired():
            self.payto_e.setGreen()
        else:
            self.payto_e.setExpired()

        self.payto_e.setText(pr.domain)
        self.amount_e.setText(self.format_amount(pr.get_amount()))
        self.message_e.setText(pr.get_memo())
        # signal to set fee
        self.amount_e.textEdited.emit("")

    def payment_request_error(self):
        self.do_clear()
        self.show_message(self.payment_request.error)
        self.payment_request = None

    def pay_from_URI(self,URI):
        if not URI:
            return
        address, amount, label, message, request_url = util.parse_URI(URI)
        try:
            address, amount, label, message, request_url = util.parse_URI(URI)
        except Exception as e:
            QMessageBox.warning(self, _('Error'), _('Invalid bitcoin URI:') + '\n' + str(e), _('OK'))
            return

        self.tabs.setCurrentIndex(1)

        if not request_url:
            if label:
                if self.wallet.labels.get(address) != label:
                    if self.question(_('Save label "%(label)s" for address %(address)s ?'%{'label':label,'address':address})):
                        if address not in self.wallet.addressbook and not self.wallet.is_mine(address):
                            self.wallet.addressbook.append(address)
                            self.wallet.set_label(address, label)
            else:
                label = self.wallet.labels.get(address)
            if address:
                self.payto_e.setText(label + '  <'+ address +'>' if label else address)
            if message:
                self.message_e.setText(message)
            if amount:
                self.amount_e.setAmount(amount)
                self.amount_e.textEdited.emit("")
            return

        from electrum import paymentrequest
        def payment_request():
            self.payment_request = paymentrequest.PaymentRequest(self.config)
            self.payment_request.read(request_url)
            if self.payment_request.verify():
                self.emit(SIGNAL('payment_request_ok'))
            else:
                self.emit(SIGNAL('payment_request_error'))

        self.pr_thread = threading.Thread(target=payment_request).start()
        self.prepare_for_payment_request()



    def do_clear(self):
        self.not_enough_funds = False
        self.payto_e.is_pr = False
        self.payto_sig.setVisible(False)
        for e in [self.payto_e, self.message_e, self.amount_e, self.fee_e]:
            e.setText('')
            e.setFrozen(False)

        for h in [self.payto_help, self.amount_help, self.message_help]:
            h.show()

        self.payto_help.set_alt(None)
        self.set_pay_from([])
        self.update_status()
        run_hook('do_clear')


    def set_addrs_frozen(self,addrs,freeze):
        for addr in addrs:
            if not addr: continue
            if addr in self.wallet.frozen_addresses and not freeze:
                self.wallet.unfreeze(addr)
            elif addr not in self.wallet.frozen_addresses and freeze:
                self.wallet.freeze(addr)
        self.update_address_tab()



    def create_list_tab(self, headers):
        "generic tab creation method"
        l = MyTreeWidget(self)
        l.setColumnCount( len(headers) )
        l.setHeaderLabels( headers )

        w = QWidget()
        vbox = QVBoxLayout()
        w.setLayout(vbox)

        vbox.setMargin(0)
        vbox.setSpacing(0)
        vbox.addWidget(l)
        buttons = QWidget()
        vbox.addWidget(buttons)

        return l, w


    def create_addresses_tab(self):
        l, w = self.create_list_tab([ _('Address'), _('Label'), _('Balance'), _('Tx')])
        for i,width in enumerate(self.column_widths['receive']):
            l.setColumnWidth(i, width)
        l.setContextMenuPolicy(Qt.CustomContextMenu)
        l.customContextMenuRequested.connect(self.create_receive_menu)
        l.setSelectionMode(QAbstractItemView.ExtendedSelection)
        l.itemDoubleClicked.connect(lambda a, b: self.address_label_clicked(a,b,l,0,1))
        l.itemChanged.connect(lambda a,b: self.address_label_changed(a,b,l,0,1))
        l.currentItemChanged.connect(lambda a,b: self.current_item_changed(a))
        self.address_list = l
        return w




    def save_column_widths(self):
        self.column_widths["receive"] = []
        for i in range(self.address_list.columnCount() -1):
            self.column_widths["receive"].append(self.address_list.columnWidth(i))

        self.column_widths["history"] = []
        for i in range(self.history_list.columnCount() - 1):
            self.column_widths["history"].append(self.history_list.columnWidth(i))

        self.column_widths["contacts"] = []
        for i in range(self.contacts_list.columnCount() - 1):
            self.column_widths["contacts"].append(self.contacts_list.columnWidth(i))

        self.config.set_key("column_widths_2", self.column_widths, True)


    def create_contacts_tab(self):
        l, w = self.create_list_tab([_('Address'), _('Label'), _('Tx')])
        l.setContextMenuPolicy(Qt.CustomContextMenu)
        l.customContextMenuRequested.connect(self.create_contact_menu)
        for i,width in enumerate(self.column_widths['contacts']):
            l.setColumnWidth(i, width)
        l.itemDoubleClicked.connect(lambda a, b: self.address_label_clicked(a,b,l,0,1))
        l.itemChanged.connect(lambda a,b: self.address_label_changed(a,b,l,0,1))
        self.contacts_list = l
        return w


    def create_invoices_tab(self):
        l, w = self.create_list_tab([_('Date'), _('Requestor'), _('Memo'), _('Amount'), _('Status')])
        l.setColumnWidth(0, 150)
        l.setColumnWidth(1, 150)
        l.setColumnWidth(3, 150)
        l.setColumnWidth(4, 40)
        h = l.header()
        h.setStretchLastSection(False)
        h.setResizeMode(2, QHeaderView.Stretch)
        l.setContextMenuPolicy(Qt.CustomContextMenu)
        l.customContextMenuRequested.connect(self.create_invoice_menu)
        self.invoices_list = l
        return w

    def update_invoices_tab(self):
        invoices = self.wallet.storage.get('invoices', {})
        l = self.invoices_list
        l.clear()
        for key, value in sorted(invoices.items(), key=lambda x: -x[1][3]):
            domain, memo, amount, expiration_date, status, tx_hash = value
            if status == PR_UNPAID and expiration_date and expiration_date < time.time():
                status = PR_EXPIRED
            date_str = datetime.datetime.fromtimestamp(expiration_date).isoformat(' ')[:-3]
            item = QTreeWidgetItem( [ date_str, domain, memo, self.format_amount(amount, whitespaces=True), ''] )
            icon = QIcon(pr_icons.get(status))
            item.setIcon(4, icon)
            item.setToolTip(4, pr_tooltips.get(status,''))
            item.setData(0, 32, key)
            item.setFont(1, QFont(MONOSPACE_FONT))
            item.setFont(3, QFont(MONOSPACE_FONT))
            l.addTopLevelItem(item)
        l.setCurrentItem(l.topLevelItem(0))

    def delete_imported_key(self, addr):
        if self.question(_("Do you want to remove")+" %s "%addr +_("from your wallet?")):
            self.wallet.delete_imported_key(addr)
            self.update_address_tab()
            self.update_history_tab()

    def edit_account_label(self, k):
        text, ok = QInputDialog.getText(self, _('Rename account'), _('Name') + ':', text = self.wallet.labels.get(k,''))
        if ok:
            label = unicode(text)
            self.wallet.set_label(k,label)
            self.update_address_tab()

    def account_set_expanded(self, item, k, b):
        item.setExpanded(b)
        self.accounts_expanded[k] = b

    def create_account_menu(self, position, k, item):
        menu = QMenu()
        exp = item.isExpanded()
        menu.addAction(_("Minimize") if exp else _("Maximize"), lambda: self.account_set_expanded(item, k, not exp))
        menu.addAction(_("Rename"), lambda: self.edit_account_label(k))
        if self.wallet.seed_version > 4:
            menu.addAction(_("View details"), lambda: self.show_account_details(k))
        if self.wallet.account_is_pending(k):
            menu.addAction(_("Delete"), lambda: self.delete_pending_account(k))
        menu.exec_(self.address_list.viewport().mapToGlobal(position))

    def delete_pending_account(self, k):
        self.wallet.delete_pending_account(k)
        self.update_address_tab()
        self.update_account_selector()

    def create_receive_menu(self, position):
        # fixme: this function apparently has a side effect.
        # if it is not called the menu pops up several times
        #self.address_list.selectedIndexes()

        selected = self.address_list.selectedItems()
        multi_select = len(selected) > 1
        addrs = [unicode(item.text(0)) for item in selected]
        if not multi_select:
            item = self.address_list.itemAt(position)
            if not item: return

            addr = addrs[0]
            if not is_valid(addr):
                k = str(item.data(0,32).toString())
                if k:
                    self.create_account_menu(position, k, item)
                else:
                    item.setExpanded(not item.isExpanded())
                return

        menu = QMenu()
        if not multi_select:
            menu.addAction(_("Copy to clipboard"), lambda: self.app.clipboard().setText(addr))
            menu.addAction(_("Request payment"), lambda: self.receive_at(addr))
            menu.addAction(_("Edit label"), lambda: self.edit_label(True))
            menu.addAction(_("Public keys"), lambda: self.show_public_keys(addr))
            if self.wallet.can_export():
                menu.addAction(_("Private key"), lambda: self.show_private_key(addr))
            if not self.wallet.is_watching_only():
                menu.addAction(_("Sign/verify message"), lambda: self.sign_verify_message(addr))
                menu.addAction(_("Encrypt/decrypt message"), lambda: self.encrypt_message(addr))
            if self.wallet.is_imported(addr):
                menu.addAction(_("Remove from wallet"), lambda: self.delete_imported_key(addr))

        if any(addr not in self.wallet.frozen_addresses for addr in addrs):
            menu.addAction(_("Freeze"), lambda: self.set_addrs_frozen(addrs, True))
        if any(addr in self.wallet.frozen_addresses for addr in addrs):
            menu.addAction(_("Unfreeze"), lambda: self.set_addrs_frozen(addrs, False))

        def can_send(addr):
            return addr not in self.wallet.frozen_addresses and self.wallet.get_addr_balance(addr) != (0, 0)
        if any(can_send(addr) for addr in addrs):
            menu.addAction(_("Send From"), lambda: self.send_from_addresses(addrs))

        run_hook('receive_menu', menu, addrs)
        menu.exec_(self.address_list.viewport().mapToGlobal(position))


    def get_sendable_balance(self):
        return sum(map(lambda x:x['value'], self.get_coins()))


    def get_coins(self):
        if self.pay_from:
            return self.pay_from
        else:
            domain = self.wallet.get_account_addresses(self.current_account)
            for i in self.wallet.frozen_addresses:
                if i in domain: domain.remove(i)
            return self.wallet.get_unspent_coins(domain)


    def send_from_addresses(self, addrs):
        self.set_pay_from( addrs )
        self.tabs.setCurrentIndex(1)


    def payto(self, addr):
        if not addr: return
        label = self.wallet.labels.get(addr)
        m_addr = label + '  <' + addr + '>' if label else addr
        self.tabs.setCurrentIndex(1)
        self.payto_e.setText(m_addr)
        self.amount_e.setFocus()


    def delete_contact(self, x):
        if self.question(_("Do you want to remove")+" %s "%x +_("from your list of contacts?")):
            self.wallet.delete_contact(x)
            self.wallet.set_label(x, None)
            self.update_history_tab()
            self.update_contacts_tab()
            self.update_completions()


    def create_contact_menu(self, position):
        item = self.contacts_list.itemAt(position)
        menu = QMenu()
        if not item:
            menu.addAction(_("New contact"), lambda: self.new_contact_dialog())
        else:
            addr = unicode(item.text(0))
            label = unicode(item.text(1))
            is_editable = item.data(0,32).toBool()
            payto_addr = item.data(0,33).toString()
            menu.addAction(_("Copy to Clipboard"), lambda: self.app.clipboard().setText(addr))
            menu.addAction(_("Pay to"), lambda: self.payto(payto_addr))
            menu.addAction(_("QR code"), lambda: self.show_qrcode("bitcoin:" + addr, _("Address")))
            if is_editable:
                menu.addAction(_("Edit label"), lambda: self.edit_label(False))
                menu.addAction(_("Delete"), lambda: self.delete_contact(addr))

        run_hook('create_contact_menu', menu, item)
        menu.exec_(self.contacts_list.viewport().mapToGlobal(position))

    def delete_invoice(self, key):
        self.invoices.pop(key)
        self.wallet.storage.put('invoices', self.invoices)
        self.update_invoices_tab()

    def show_invoice(self, key):
        from electrum.paymentrequest import PaymentRequest
        domain, memo, value, expiration, status, tx_hash = self.invoices[key]
        pr = PaymentRequest(self.config)
        pr.read_file(key)
        pr.domain = domain
        pr.verify()
        self.show_pr_details(pr, tx_hash)

    def show_pr_details(self, pr, tx_hash=None):
        msg = 'Domain: ' + pr.domain
        msg += '\nStatus: ' + pr.get_status()
        msg += '\nMemo: ' + pr.get_memo()
        msg += '\nPayment URL: ' + pr.payment_url
        msg += '\n\nOutputs:\n' + '\n'.join(map(lambda x: x[1] + ' ' + self.format_amount(x[2])+ self.base_unit(), pr.get_outputs()))
        if tx_hash:
            msg += '\n\nTransaction ID: ' + tx_hash
        QMessageBox.information(self, 'Invoice', msg , 'OK')

    def do_pay_invoice(self, key):
        from electrum.paymentrequest import PaymentRequest
        domain, memo, value, expiration, status, tx_hash = self.invoices[key]
        pr = PaymentRequest(self.config)
        pr.read_file(key)
        pr.domain = domain
        self.payment_request = pr
        self.prepare_for_payment_request()
        if pr.verify():
            self.payment_request_ok()
        else:
            self.payment_request_error()


    def create_invoice_menu(self, position):
        item = self.invoices_list.itemAt(position)
        if not item:
            return
        key = str(item.data(0, 32).toString())
        domain, memo, value, expiration, status, tx_hash = self.invoices[key]
        menu = QMenu()
        menu.addAction(_("Details"), lambda: self.show_invoice(key))
        if status == PR_UNPAID:
            menu.addAction(_("Pay Now"), lambda: self.do_pay_invoice(key))
        menu.addAction(_("Delete"), lambda: self.delete_invoice(key))
        menu.exec_(self.invoices_list.viewport().mapToGlobal(position))



    def update_address_tab(self):
        l = self.address_list
        # extend the syntax for consistency
        l.addChild = l.addTopLevelItem
        l.insertChild = l.insertTopLevelItem

        l.clear()

        accounts = self.wallet.get_accounts()
        if self.current_account is None:
            account_items = sorted(accounts.items())
        else:
            account_items = [(self.current_account, accounts.get(self.current_account))]


        for k, account in account_items:

            if len(accounts) > 1:
                name = self.wallet.get_account_name(k)
                c,u = self.wallet.get_account_balance(k)
                account_item = QTreeWidgetItem( [ name, '', self.format_amount(c+u), ''] )
                l.addTopLevelItem(account_item)
                account_item.setExpanded(self.accounts_expanded.get(k, True))
                account_item.setData(0, 32, k)
            else:
                account_item = l

            sequences = [0,1] if account.has_change() else [0]
            for is_change in sequences:
                if len(sequences) > 1:
                    name = _("Receiving") if not is_change else _("Change")
                    seq_item = QTreeWidgetItem( [ name, '', '', '', ''] )
                    account_item.addChild(seq_item)
                    if not is_change:
                        seq_item.setExpanded(True)
                else:
                    seq_item = account_item

                used_item = QTreeWidgetItem( [ _("Used"), '', '', '', ''] )
                used_flag = False

                addr_list = account.get_addresses(is_change)
                for address in addr_list:
                    num, is_used = self.wallet.is_used(address)
                    label = self.wallet.labels.get(address,'')
                    c, u = self.wallet.get_addr_balance(address)
                    balance = self.format_amount(c + u)
                    item = QTreeWidgetItem( [ address, label, balance, "%d"%num] )
                    item.setFont(0, QFont(MONOSPACE_FONT))
                    item.setData(0, 32, True) # label can be edited
                    if address in self.wallet.frozen_addresses:
                        item.setBackgroundColor(0, QColor('lightblue'))
                    if self.wallet.is_beyond_limit(address, account, is_change):
                        item.setBackgroundColor(0, QColor('red'))
                    if is_used:
                        if not used_flag:
                            seq_item.insertChild(0, used_item)
                            used_flag = True
                        used_item.addChild(item)
                    else:
                        seq_item.addChild(item)

        # we use column 1 because column 0 may be hidden
        l.setCurrentItem(l.topLevelItem(0),1)


    def update_contacts_tab(self):
        l = self.contacts_list
        l.clear()

        for address in self.wallet.addressbook:
            label = self.wallet.labels.get(address,'')
            n = self.wallet.get_num_tx(address)
            item = QTreeWidgetItem( [ address, label, "%d"%n] )
            item.setFont(0, QFont(MONOSPACE_FONT))
            # 32 = label can be edited (bool)
            item.setData(0,32, True)
            # 33 = payto string
            item.setData(0,33, address)
            l.addTopLevelItem(item)

        run_hook('update_contacts_tab', l)
        l.setCurrentItem(l.topLevelItem(0))


    def create_console_tab(self):
        from console import Console
        self.console = console = Console()
        return console


    def update_console(self):
        console = self.console
        console.history = self.config.get("console-history",[])
        console.history_index = len(console.history)

        console.updateNamespace({'wallet' : self.wallet, 'network' : self.network, 'gui':self})
        console.updateNamespace({'util' : util, 'bitcoin':bitcoin})

        c = commands.Commands(self.wallet, self.network, lambda: self.console.set_json(True))
        methods = {}
        def mkfunc(f, method):
            return lambda *args: apply( f, (method, args, self.password_dialog ))
        for m in dir(c):
            if m[0]=='_' or m in ['network','wallet']: continue
            methods[m] = mkfunc(c._run, m)

        console.updateNamespace(methods)


    def change_account(self,s):
        if s == _("All accounts"):
            self.current_account = None
        else:
            accounts = self.wallet.get_account_names()
            for k, v in accounts.items():
                if v == s:
                    self.current_account = k
        self.update_history_tab()
        self.update_status()
        self.update_address_tab()
        self.update_receive_tab()

    def create_status_bar(self):

        sb = QStatusBar()
        sb.setFixedHeight(35)
        qtVersion = qVersion()

        self.balance_label = QLabel("")
        sb.addWidget(self.balance_label)

        from version_getter import UpdateLabel
        self.updatelabel = UpdateLabel(self.config, sb)

        self.account_selector = QComboBox()
        self.account_selector.setSizeAdjustPolicy(QComboBox.AdjustToContents)
        self.connect(self.account_selector,SIGNAL("activated(QString)"),self.change_account)
        sb.addPermanentWidget(self.account_selector)

        if (int(qtVersion[0]) >= 4 and int(qtVersion[2]) >= 7):
            sb.addPermanentWidget( StatusBarButton( QIcon(":icons/switchgui.png"), _("Switch to Lite Mode"), self.go_lite ) )

        self.lock_icon = QIcon()
        self.password_button = StatusBarButton( self.lock_icon, _("Password"), self.change_password_dialog )
        sb.addPermanentWidget( self.password_button )

        sb.addPermanentWidget( StatusBarButton( QIcon(":icons/preferences.png"), _("Preferences"), self.settings_dialog ) )
        self.seed_button = StatusBarButton( QIcon(":icons/seed.png"), _("Seed"), self.show_seed_dialog )
        sb.addPermanentWidget( self.seed_button )
        self.status_button = StatusBarButton( QIcon(":icons/status_disconnected.png"), _("Network"), self.run_network_dialog )
        sb.addPermanentWidget( self.status_button )

        run_hook('create_status_bar', sb)

        self.setStatusBar(sb)


    def update_lock_icon(self):
        icon = QIcon(":icons/lock.png") if self.wallet.use_encryption else QIcon(":icons/unlock.png")
        self.password_button.setIcon( icon )


    def update_buttons_on_seed(self):
        self.seed_button.setVisible(self.wallet.has_seed())
        self.password_button.setVisible(self.wallet.can_change_password())
        self.send_button.setText(_("Create unsigned transaction") if self.wallet.is_watching_only() else _("Send"))


    def change_password_dialog(self):
        from password_dialog import PasswordDialog
        d = PasswordDialog(self.wallet, self)
        d.run()
        self.update_lock_icon()


    def new_contact_dialog(self):

        d = QDialog(self)
        d.setWindowTitle(_("New Contact"))
        vbox = QVBoxLayout(d)
        vbox.addWidget(QLabel(_('New Contact')+':'))

        grid = QGridLayout()
        line1 = QLineEdit()
        line2 = QLineEdit()
        grid.addWidget(QLabel(_("Address")), 1, 0)
        grid.addWidget(line1, 1, 1)
        grid.addWidget(QLabel(_("Name")), 2, 0)
        grid.addWidget(line2, 2, 1)

        vbox.addLayout(grid)
        vbox.addLayout(ok_cancel_buttons(d))

        if not d.exec_():
            return

        address = str(line1.text())
        label = unicode(line2.text())

        if not is_valid(address):
            QMessageBox.warning(self, _('Error'), _('Invalid Address'), _('OK'))
            return

        self.wallet.add_contact(address)
        if label:
            self.wallet.set_label(address, label)

        self.update_contacts_tab()
        self.update_history_tab()
        self.update_completions()
        self.tabs.setCurrentIndex(3)


    @protected
    def new_account_dialog(self, password):

        dialog = QDialog(self)
        dialog.setModal(1)
        dialog.setWindowTitle(_("New Account"))

        vbox = QVBoxLayout()
        vbox.addWidget(QLabel(_('Account name')+':'))
        e = QLineEdit()
        vbox.addWidget(e)
        msg = _("Note: Newly created accounts are 'pending' until they receive bitcoins.") + " " \
            + _("You will need to wait for 2 confirmations until the correct balance is displayed and more addresses are created for that account.")
        l = QLabel(msg)
        l.setWordWrap(True)
        vbox.addWidget(l)

        vbox.addLayout(ok_cancel_buttons(dialog))
        dialog.setLayout(vbox)
        r = dialog.exec_()
        if not r: return

        name = str(e.text())

        self.wallet.create_pending_account(name, password)
        self.update_address_tab()
        self.update_account_selector()
        self.tabs.setCurrentIndex(3)




    def show_master_public_keys(self):

        dialog = QDialog(self)
        dialog.setModal(1)
        dialog.setWindowTitle(_("Master Public Keys"))

        mpk_dict = self.wallet.get_master_public_keys()
        vbox = QVBoxLayout()
        # only show the combobox in case multiple accounts are available
        if len(mpk_dict) > 1:
            gb = QGroupBox(_("Master Public Keys"))
            vbox.addWidget(gb)
            group = QButtonGroup()
            first_button = None
            for name in sorted(mpk_dict.keys()):
                b = QRadioButton(gb)
                b.setText(name)
                group.addButton(b)
                vbox.addWidget(b)
                if not first_button:
                    first_button = b

            mpk_text = ShowQRTextEdit()
            mpk_text.setMaximumHeight(170)
            vbox.addWidget(mpk_text)

            def show_mpk(b):
                name = str(b.text())
                mpk = mpk_dict.get(name, "")
                mpk_text.setText(mpk)
                mpk_text.selectAll()    # for easy copying

            group.buttonReleased.connect(show_mpk)
            first_button.setChecked(True)
            show_mpk(first_button)

            #combobox.currentIndexChanged[str].connect(lambda acc: show_mpk(acc))
        elif len(mpk_dict) == 1:
            mpk = mpk_dict.values()[0]
            mpk_text = ShowQRTextEdit(text=mpk)
            mpk_text.setMaximumHeight(170)
            mpk_text.selectAll()    # for easy copying
            vbox.addWidget(mpk_text)

        vbox.addLayout(close_button(dialog))

        dialog.setLayout(vbox)
        dialog.exec_()

    @protected
    def show_seed_dialog(self, password):
        if not self.wallet.has_seed():
            QMessageBox.information(self, _('Message'), _('This wallet has no seed'), _('OK'))
            return

        try:
            mnemonic = self.wallet.get_mnemonic(password)
        except BaseException as e:
            QMessageBox.warning(self, _('Error'), str(e), _('OK'))
            return
        from seed_dialog import SeedDialog
        d = SeedDialog(self, mnemonic, self.wallet.has_imported_keys())
        d.exec_()



    def show_qrcode(self, data, title = _("QR code")):
        if not data:
            return
        d = QRDialog(data, self, title)
        d.exec_()


    def do_protect(self, func, args):
        if self.wallet.use_encryption:
            password = self.password_dialog()
            if not password:
                return
        else:
            password = None

        if args != (False,):
            args = (self,) + args + (password,)
        else:
            args = (self,password)
        apply( func, args)


    def show_public_keys(self, address):
        if not address: return
        try:
            pubkey_list = self.wallet.get_public_keys(address)
        except Exception as e:
            traceback.print_exc(file=sys.stdout)
            self.show_message(str(e))
            return

        d = QDialog(self)
        d.setMinimumSize(600, 200)
        d.setModal(1)
        d.setWindowTitle(_("Public key"))
        vbox = QVBoxLayout()
        vbox.addWidget( QLabel(_("Address") + ': ' + address))
        vbox.addWidget( QLabel(_("Public key") + ':'))
        keys = ShowQRTextEdit(text='\n'.join(pubkey_list))
        vbox.addWidget(keys)
        vbox.addLayout(close_button(d))
        d.setLayout(vbox)
        d.exec_()

    @protected
    def show_private_key(self, address, password):
        if not address: return
        try:
            pk_list = self.wallet.get_private_key(address, password)
        except Exception as e:
            traceback.print_exc(file=sys.stdout)
            self.show_message(str(e))
            return

        d = QDialog(self)
        d.setMinimumSize(600, 200)
        d.setModal(1)
        d.setWindowTitle(_("Private key"))
        vbox = QVBoxLayout()
        vbox.addWidget( QLabel(_("Address") + ': ' + address))
        vbox.addWidget( QLabel(_("Private key") + ':'))
        keys = ShowQRTextEdit(text='\n'.join(pk_list))
        vbox.addWidget(keys)
        vbox.addLayout(close_button(d))
        d.setLayout(vbox)
        d.exec_()


    @protected
    def do_sign(self, address, message, signature, password):
        message = unicode(message.toPlainText())
        message = message.encode('utf-8')
        try:
            sig = self.wallet.sign_message(str(address.text()), message, password)
            signature.setText(sig)
        except Exception as e:
            self.show_message(str(e))

    def do_verify(self, address, message, signature):
        message = unicode(message.toPlainText())
        message = message.encode('utf-8')
        if bitcoin.verify_message(address.text(), str(signature.toPlainText()), message):
            self.show_message(_("Signature verified"))
        else:
            self.show_message(_("Error: wrong signature"))


    def sign_verify_message(self, address=''):
        d = QDialog(self)
        d.setModal(1)
        d.setWindowTitle(_('Sign/verify Message'))
        d.setMinimumSize(410, 290)

        layout = QGridLayout(d)

        message_e = QTextEdit()
        layout.addWidget(QLabel(_('Message')), 1, 0)
        layout.addWidget(message_e, 1, 1)
        layout.setRowStretch(2,3)

        address_e = QLineEdit()
        address_e.setText(address)
        layout.addWidget(QLabel(_('Address')), 2, 0)
        layout.addWidget(address_e, 2, 1)

        signature_e = QTextEdit()
        layout.addWidget(QLabel(_('Signature')), 3, 0)
        layout.addWidget(signature_e, 3, 1)
        layout.setRowStretch(3,1)

        hbox = QHBoxLayout()

        b = QPushButton(_("Sign"))
        b.clicked.connect(lambda: self.do_sign(address_e, message_e, signature_e))
        hbox.addWidget(b)

        b = QPushButton(_("Verify"))
        b.clicked.connect(lambda: self.do_verify(address_e, message_e, signature_e))
        hbox.addWidget(b)

        b = QPushButton(_("Close"))
        b.clicked.connect(d.accept)
        hbox.addWidget(b)
        layout.addLayout(hbox, 4, 1)
        d.exec_()


    @protected
    def do_decrypt(self, message_e, pubkey_e, encrypted_e, password):
        try:
            decrypted = self.wallet.decrypt_message(str(pubkey_e.text()), str(encrypted_e.toPlainText()), password)
            message_e.setText(decrypted)
        except BaseException as e:
            traceback.print_exc(file=sys.stdout)
            self.show_warning(str(e))


    def do_encrypt(self, message_e, pubkey_e, encrypted_e):
        message = unicode(message_e.toPlainText())
        message = message.encode('utf-8')
        try:
            encrypted = bitcoin.encrypt_message(message, str(pubkey_e.text()))
            encrypted_e.setText(encrypted)
        except BaseException as e:
            traceback.print_exc(file=sys.stdout)
            self.show_warning(str(e))


    def encrypt_message(self, address = ''):
        d = QDialog(self)
        d.setModal(1)
        d.setWindowTitle(_('Encrypt/decrypt Message'))
        d.setMinimumSize(610, 490)

        layout = QGridLayout(d)

        message_e = QTextEdit()
        layout.addWidget(QLabel(_('Message')), 1, 0)
        layout.addWidget(message_e, 1, 1)
        layout.setRowStretch(2,3)

        pubkey_e = QLineEdit()
        if address:
            pubkey = self.wallet.get_public_keys(address)[0]
            pubkey_e.setText(pubkey)
        layout.addWidget(QLabel(_('Public key')), 2, 0)
        layout.addWidget(pubkey_e, 2, 1)

        encrypted_e = QTextEdit()
        layout.addWidget(QLabel(_('Encrypted')), 3, 0)
        layout.addWidget(encrypted_e, 3, 1)
        layout.setRowStretch(3,1)

        hbox = QHBoxLayout()
        b = QPushButton(_("Encrypt"))
        b.clicked.connect(lambda: self.do_encrypt(message_e, pubkey_e, encrypted_e))
        hbox.addWidget(b)

        b = QPushButton(_("Decrypt"))
        b.clicked.connect(lambda: self.do_decrypt(message_e, pubkey_e, encrypted_e))
        hbox.addWidget(b)

        b = QPushButton(_("Close"))
        b.clicked.connect(d.accept)
        hbox.addWidget(b)

        layout.addLayout(hbox, 4, 1)
        d.exec_()


    def question(self, msg):
        return QMessageBox.question(self, _('Message'), msg, QMessageBox.Yes | QMessageBox.No, QMessageBox.No) == QMessageBox.Yes

    def show_message(self, msg):
        QMessageBox.information(self, _('Message'), msg, _('OK'))

    def show_warning(self, msg):
        QMessageBox.warning(self, _('Warning'), msg, _('OK'))

    def password_dialog(self, msg=None):
        d = QDialog(self)
        d.setModal(1)
        d.setWindowTitle(_("Enter Password"))

        pw = QLineEdit()
        pw.setEchoMode(2)

        vbox = QVBoxLayout()
        if not msg:
            msg = _('Please enter your password')
        vbox.addWidget(QLabel(msg))

        grid = QGridLayout()
        grid.setSpacing(8)
        grid.addWidget(QLabel(_('Password')), 1, 0)
        grid.addWidget(pw, 1, 1)
        vbox.addLayout(grid)

        vbox.addLayout(ok_cancel_buttons(d))
        d.setLayout(vbox)

        run_hook('password_dialog', pw, grid, 1)
        if not d.exec_(): return
        return unicode(pw.text())








    def tx_from_text(self, txt):
        "json or raw hexadecimal"
        try:
            txt.decode('hex')
            is_hex = True
        except:
            is_hex = False

        if is_hex:
            try:
                return Transaction.deserialize(txt)
            except:
                traceback.print_exc(file=sys.stdout)
                QMessageBox.critical(None, _("Unable to parse transaction"), _("Electrum was unable to parse your transaction"))
                return

        try:
            tx_dict = json.loads(str(txt))
            assert "hex" in tx_dict.keys()
            tx = Transaction.deserialize(tx_dict["hex"])
            #if tx_dict.has_key("input_info"):
            #    input_info = json.loads(tx_dict['input_info'])
            #    tx.add_input_info(input_info)
            return tx
        except Exception:
            traceback.print_exc(file=sys.stdout)
            QMessageBox.critical(None, _("Unable to parse transaction"), _("Electrum was unable to parse your transaction"))


    def read_tx_from_qrcode(self):
        from electrum import qrscanner
        try:
            data = qrscanner.scan_qr(self.config)
        except BaseException, e:
            QMessageBox.warning(self, _('Error'), _(e), _('OK'))
            return
        if not data:
            return
        # if the user scanned a bitcoin URI
        if data.startswith("bitcoin:"):
            self.pay_from_URI(data)
            return
        # else if the user scanned an offline signed tx
        # transactions are binary, but qrcode seems to return utf8...
        z = data.decode('utf8')
        data = ''.join(chr(ord(b)) for b in z).encode('hex')
        tx = self.tx_from_text(data)
        if not tx:
            return
        self.show_transaction(tx)


    def read_tx_from_file(self):
        fileName = self.getOpenFileName(_("Select your transaction file"), "*.txn")
        if not fileName:
            return
        try:
            with open(fileName, "r") as f:
                file_content = f.read()
        except (ValueError, IOError, os.error), reason:
            QMessageBox.critical(None, _("Unable to read file or no transaction found"), _("Electrum was unable to open your transaction file") + "\n" + str(reason))

        return self.tx_from_text(file_content)


    @protected
    def sign_raw_transaction(self, tx, password):
        try:
            self.wallet.sign_transaction(tx, password)
        except Exception as e:
            traceback.print_exc(file=sys.stdout)
            QMessageBox.warning(self, _("Error"), str(e))

    def do_process_from_text(self):
        text = text_dialog(self, _('Input raw transaction'), _("Transaction:"), _("Load transaction"))
        if not text:
            return
        tx = self.tx_from_text(text)
        if tx:
            self.show_transaction(tx)

    def do_process_from_file(self):
        tx = self.read_tx_from_file()
        if tx:
            self.show_transaction(tx)

    def do_process_from_txid(self):
        from electrum import transaction
        txid, ok = QInputDialog.getText(self, _('Lookup transaction'), _('Transaction ID') + ':')
        if ok and txid:
            r = self.network.synchronous_get([ ('blockchain.transaction.get',[str(txid)]) ])[0]
            if r:
                tx = transaction.Transaction.deserialize(r)
                if tx:
                    self.show_transaction(tx)
                else:
                    self.show_message("unknown transaction")

    def do_process_from_csvReader(self, csvReader):
        outputs = []
        errors = []
        errtext = ""
        try:
            for position, row in enumerate(csvReader):
                address = row[0]
                if not bitcoin.is_address(address):
                    errors.append((position, address))
                    continue
                amount = Decimal(row[1])
                amount = int(100000000*amount)
                outputs.append(('address', address, amount))
        except (ValueError, IOError, os.error), reason:
            QMessageBox.critical(None, _("Unable to read file or no transaction found"), _("Electrum was unable to open your transaction file") + "\n" + str(reason))
            return
        if errors != []:
            for x in errors:
                errtext += "CSV Row " + str(x[0]+1) + ": " + x[1] + "\n"
            QMessageBox.critical(None, _("Invalid Addresses"), _("ABORTING! Invalid Addresses found:") + "\n\n" + errtext)
            return

        try:
            tx = self.wallet.make_unsigned_transaction(outputs, None, None)
        except Exception as e:
            self.show_message(str(e))
            return

        self.show_transaction(tx)

    def do_process_from_csv_file(self):
        fileName = self.getOpenFileName(_("Select your transaction CSV"), "*.csv")
        if not fileName:
            return
        try:
            with open(fileName, "r") as f:
                csvReader = csv.reader(f)
                self.do_process_from_csvReader(csvReader)
        except (ValueError, IOError, os.error), reason:
            QMessageBox.critical(None, _("Unable to read file or no transaction found"), _("Electrum was unable to open your transaction file") + "\n" + str(reason))
            return

    def do_process_from_csv_text(self):
        text = text_dialog(self, _('Input CSV'), _("Please enter a list of outputs.") + '\n' \
                               + _("Format: address, amount. One output per line"), _("Load CSV"))
        if not text:
            return
        f = StringIO.StringIO(text)
        csvReader = csv.reader(f)
        self.do_process_from_csvReader(csvReader)



    @protected
    def export_privkeys_dialog(self, password):
        if self.wallet.is_watching_only():
            self.show_message(_("This is a watching-only wallet"))
            return

        try:
            self.wallet.check_password(password)
        except Exception as e:
            QMessageBox.warning(self, _('Error'), str(e), _('OK'))
            return

        d = QDialog(self)
        d.setWindowTitle(_('Private keys'))
        d.setMinimumSize(850, 300)
        vbox = QVBoxLayout(d)

        msg = "%s\n%s\n%s" % (_("WARNING: ALL your private keys are secret."),
                              _("Exposing a single private key can compromise your entire wallet!"),
                              _("In particular, DO NOT use 'redeem private key' services proposed by third parties."))
        vbox.addWidget(QLabel(msg))

        e = QTextEdit()
        e.setReadOnly(True)
        vbox.addWidget(e)

        defaultname = 'electrum-private-keys.csv'
        select_msg = _('Select file to export your private keys to')
        hbox, filename_e, csv_button = filename_field(self, self.config, defaultname, select_msg)
        vbox.addLayout(hbox)

        h, b = ok_cancel_buttons2(d, _('Export'))
        b.setEnabled(False)
        vbox.addLayout(h)

        private_keys = {}
        addresses = self.wallet.addresses(True)
        done = False
        def privkeys_thread():
            for addr in addresses:
                time.sleep(0.1)
                if done:
                    break
                private_keys[addr] = "\n".join(self.wallet.get_private_key(addr, password))
                d.emit(SIGNAL('computing_privkeys'))
            d.emit(SIGNAL('show_privkeys'))

        def show_privkeys():
            s = "\n".join( map( lambda x: x[0] + "\t"+ x[1], private_keys.items()))
            e.setText(s)
            b.setEnabled(True)

        d.connect(d, QtCore.SIGNAL('computing_privkeys'), lambda: e.setText("Please wait... %d/%d"%(len(private_keys),len(addresses))))
        d.connect(d, QtCore.SIGNAL('show_privkeys'), show_privkeys)
        threading.Thread(target=privkeys_thread).start()

        if not d.exec_():
            done = True
            return

        filename = filename_e.text()
        if not filename:
            return

        try:
            self.do_export_privkeys(filename, private_keys, csv_button.isChecked())
        except (IOError, os.error), reason:
            export_error_label = _("Electrum was unable to produce a private key-export.")
            QMessageBox.critical(None, _("Unable to create csv"), export_error_label + "\n" + str(reason))

        except Exception as e:
            self.show_message(str(e))
            return

        self.show_message(_("Private keys exported."))


    def do_export_privkeys(self, fileName, pklist, is_csv):
        with open(fileName, "w+") as f:
            if is_csv:
                transaction = csv.writer(f)
                transaction.writerow(["address", "private_key"])
                for addr, pk in pklist.items():
                    transaction.writerow(["%34s"%addr,pk])
            else:
                import json
                f.write(json.dumps(pklist, indent = 4))


    def do_import_labels(self):
        labelsFile = self.getOpenFileName(_("Open labels file"), "*.dat")
        if not labelsFile: return
        try:
            f = open(labelsFile, 'r')
            data = f.read()
            f.close()
            for key, value in json.loads(data).items():
                self.wallet.set_label(key, value)
            QMessageBox.information(None, _("Labels imported"), _("Your labels were imported from")+" '%s'" % str(labelsFile))
        except (IOError, os.error), reason:
            QMessageBox.critical(None, _("Unable to import labels"), _("Electrum was unable to import your labels.")+"\n" + str(reason))


    def do_export_labels(self):
        labels = self.wallet.labels
        try:
            fileName = self.getSaveFileName(_("Select file to save your labels"), 'electrum_labels.dat', "*.dat")
            if fileName:
                with open(fileName, 'w+') as f:
                    json.dump(labels, f)
                QMessageBox.information(None, _("Labels exported"), _("Your labels where exported to")+" '%s'" % str(fileName))
        except (IOError, os.error), reason:
            QMessageBox.critical(None, _("Unable to export labels"), _("Electrum was unable to export your labels.")+"\n" + str(reason))


    def export_history_dialog(self):

        d = QDialog(self)
        d.setWindowTitle(_('Export History'))
        d.setMinimumSize(400, 200)
        vbox = QVBoxLayout(d)

        defaultname = os.path.expanduser('~/electrum-history.csv')
        select_msg = _('Select file to export your wallet transactions to')

        hbox, filename_e, csv_button = filename_field(self, self.config, defaultname, select_msg)
        vbox.addLayout(hbox)

        vbox.addStretch(1)

        h, b = ok_cancel_buttons2(d, _('Export'))
        vbox.addLayout(h)

        run_hook('export_history_dialog', self,hbox)
        self.update()

        if not d.exec_():
            return

        filename = filename_e.text()
        if not filename:
            return

        try:
            self.do_export_history(self.wallet, filename, csv_button.isChecked())
        except (IOError, os.error), reason:
            export_error_label = _("Electrum was unable to produce a transaction export.")
            QMessageBox.critical(self, _("Unable to export history"), export_error_label + "\n" + str(reason))
            return

        QMessageBox.information(self,_("History exported"), _("Your wallet history has been successfully exported."))


    def do_export_history(self, wallet, fileName, is_csv):
        history = wallet.get_tx_history()
        lines = []
        for item in history:
            tx_hash, confirmations, is_mine, value, fee, balance, timestamp = item
            if confirmations:
                if timestamp is not None:
                    try:
                        time_string = datetime.datetime.fromtimestamp(timestamp).isoformat(' ')[:-3]
                    except [RuntimeError, TypeError, NameError] as reason:
                        time_string = "unknown"
                        pass
                else:
                    time_string = "unknown"
            else:
                time_string = "pending"

            if value is not None:
                value_string = format_satoshis(value, True)
            else:
                value_string = '--'

            if fee is not None:
                fee_string = format_satoshis(fee, True)
            else:
                fee_string = '0'

            if tx_hash:
                label, is_default_label = wallet.get_label(tx_hash)
                label = label.encode('utf-8')
            else:
                label = ""

            balance_string = format_satoshis(balance, False)
            if is_csv:
                lines.append([tx_hash, label, confirmations, value_string, fee_string, balance_string, time_string])
            else:
                lines.append({'txid':tx_hash, 'date':"%16s"%time_string, 'label':label, 'value':value_string})

        with open(fileName, "w+") as f:
            if is_csv:
                transaction = csv.writer(f, lineterminator='\n')
                transaction.writerow(["transaction_hash","label", "confirmations", "value", "fee", "balance", "timestamp"])
                for line in lines:
                    transaction.writerow(line)
            else:
                import json
                f.write(json.dumps(lines, indent = 4))


    def sweep_key_dialog(self):
        d = QDialog(self)
        d.setWindowTitle(_('Sweep private keys'))
        d.setMinimumSize(600, 300)

        vbox = QVBoxLayout(d)
        vbox.addWidget(QLabel(_("Enter private keys")))

        keys_e = QTextEdit()
        keys_e.setTabChangesFocus(True)
        vbox.addWidget(keys_e)

        h, address_e = address_field(self.wallet.addresses(False))
        vbox.addLayout(h)

        vbox.addStretch(1)
        hbox, button = ok_cancel_buttons2(d, _('Sweep'))
        vbox.addLayout(hbox)
        button.setEnabled(False)

        def get_address():
            addr = str(address_e.text())
            if bitcoin.is_address(addr):
                return addr

        def get_pk():
            pk = str(keys_e.toPlainText()).strip()
            if Wallet.is_private_key(pk):
                return pk.split()

        f = lambda: button.setEnabled(get_address() is not None and get_pk() is not None)
        keys_e.textChanged.connect(f)
        address_e.textChanged.connect(f)
        if not d.exec_():
            return

        fee = self.wallet.fee_per_kb
        tx = Transaction.sweep(get_pk(), self.network, get_address(), fee)
        self.show_transaction(tx)


    @protected
    def do_import_privkey(self, password):
        if not self.wallet.has_imported_keys():
            r = QMessageBox.question(None, _('Warning'), '<b>'+_('Warning') +':\n</b><br/>'+ _('Imported keys are not recoverable from seed.') + ' ' \
                                         + _('If you ever need to restore your wallet from its seed, these keys will be lost.') + '<p>' \
                                         + _('Are you sure you understand what you are doing?'), 3, 4)
            if r == 4: return

        text = text_dialog(self, _('Import private keys'), _("Enter private keys")+':', _("Import"))
        if not text: return

        text = str(text).split()
        badkeys = []
        addrlist = []
        for key in text:
            try:
                addr = self.wallet.import_key(key, password)
            except Exception as e:
                badkeys.append(key)
                continue
            if not addr:
                badkeys.append(key)
            else:
                addrlist.append(addr)
        if addrlist:
            QMessageBox.information(self, _('Information'), _("The following addresses were added") + ':\n' + '\n'.join(addrlist))
        if badkeys:
            QMessageBox.critical(self, _('Error'), _("The following inputs could not be imported") + ':\n'+ '\n'.join(badkeys))
        self.update_address_tab()
        self.update_history_tab()


    def settings_dialog(self):
        self.need_restart = False
        d = QDialog(self)
        d.setWindowTitle(_('Electrum Settings'))
        d.setModal(1)
        vbox = QVBoxLayout()
        grid = QGridLayout()
        grid.setColumnStretch(0,1)
        widgets = []

        lang_label = QLabel(_('Language') + ':')
        lang_help = HelpButton(_('Select which language is used in the GUI (after restart).'))
        lang_combo = QComboBox()
        from electrum.i18n import languages
        lang_combo.addItems(languages.values())
        try:
            index = languages.keys().index(self.config.get("language",''))
        except Exception:
            index = 0
        lang_combo.setCurrentIndex(index)
        if not self.config.is_modifiable('language'):
            for w in [lang_combo, lang_label]: w.setEnabled(False)
        def on_lang(x):
            lang_request = languages.keys()[lang_combo.currentIndex()]
            if lang_request != self.config.get('language'):
                self.config.set_key("language", lang_request, True)
                self.need_restart = True
        lang_combo.currentIndexChanged.connect(on_lang)
        widgets.append((lang_label, lang_combo, lang_help))

        nz_label = QLabel(_('Zeros after decimal point') + ':')
        nz_help = HelpButton(_('Number of zeros displayed after the decimal point. For example, if this is set to 2, "1." will be displayed as "1.00"'))
        nz = QSpinBox()
        nz.setMinimum(0)
        nz.setMaximum(self.decimal_point)
        nz.setValue(self.num_zeros)
        if not self.config.is_modifiable('num_zeros'):
            for w in [nz, nz_label]: w.setEnabled(False)
        def on_nz():
            value = nz.value()
            if self.num_zeros != value:
                self.num_zeros = value
                self.config.set_key('num_zeros', value, True)
                self.update_history_tab()
                self.update_address_tab()
        nz.valueChanged.connect(on_nz)
        widgets.append((nz_label, nz, nz_help))

        fee_label = QLabel(_('Transaction fee per kb') + ':')
        fee_help = HelpButton(_('Fee per kilobyte of transaction.') + '\n' \
                              + _('Recommended value') + ': ' + self.format_amount(bitcoin.RECOMMENDED_FEE) + ' ' + self.base_unit())
        fee_e = BTCAmountEdit(self.get_decimal_point)
        fee_e.setAmount(self.wallet.fee_per_kb)
        if not self.config.is_modifiable('fee_per_kb'):
            for w in [fee_e, fee_label]: w.setEnabled(False)
        def on_fee():
            fee = fee_e.get_amount()
            self.wallet.set_fee(fee)
        fee_e.editingFinished.connect(on_fee)
        widgets.append((fee_label, fee_e, fee_help))

        units = ['BTC', 'mBTC', 'bits']
        unit_label = QLabel(_('Base unit') + ':')
        unit_combo = QComboBox()
        unit_combo.addItems(units)
        unit_combo.setCurrentIndex(units.index(self.base_unit()))
        msg = _('Base unit of your wallet.')\
              + '\n1BTC=1000mBTC.\n' \
              + _(' These settings affects the fields in the Send tab')+' '
        unit_help = HelpButton(msg)
        def on_unit(x):
            unit_result = units[unit_combo.currentIndex()]
            if self.base_unit() == unit_result:
                return
            if unit_result == 'BTC':
                self.decimal_point = 8
            elif unit_result == 'mBTC':
                self.decimal_point = 5
            elif unit_result == 'bits':
                self.decimal_point = 2
            else:
                raise Exception('Unknown base unit')
            self.config.set_key('decimal_point', self.decimal_point, True)
            self.update_history_tab()
            self.update_receive_tab()
            self.update_address_tab()
            self.update_invoices_tab()
            fee_e.setAmount(self.wallet.fee_per_kb)
            self.update_status()
        unit_combo.currentIndexChanged.connect(on_unit)
        widgets.append((unit_label, unit_combo, unit_help))

        block_explorers = ['Blockchain.info', 'Blockr.io', 'Insight.is', "Blocktrail.com"]
        block_ex_label = QLabel(_('Online Block Explorer') + ':')
        block_ex_combo = QComboBox()
        block_ex_combo.addItems(block_explorers)
        block_ex_combo.setCurrentIndex(block_explorers.index(self.config.get('block_explorer', 'Blockchain.info')))
        block_ex_help = HelpButton(_('Choose which online block explorer to use for functions that open a web browser'))
        def on_be(x):
            be_result = block_explorers[block_ex_combo.currentIndex()]
            self.config.set_key('block_explorer', be_result, True)
        block_ex_combo.currentIndexChanged.connect(on_be)
        widgets.append((block_ex_label, block_ex_combo, block_ex_help))

        from electrum import qrscanner
        system_cameras = qrscanner._find_system_cameras()
        qr_combo = QComboBox()
        qr_combo.addItem("Default","default")
        for camera, device in system_cameras.items():
            qr_combo.addItem(camera, device)
        #combo.addItem("Manually specify a device", config.get("video_device"))
        index = qr_combo.findData(self.config.get("video_device"))
        qr_combo.setCurrentIndex(index)
        qr_label = QLabel(_('Video Device') + ':')
        qr_combo.setEnabled(qrscanner.zbar is not None)
        qr_help = HelpButton(_("Install the zbar package to enable this.\nOn linux, type: 'apt-get install python-zbar'"))
        on_video_device = lambda x: self.config.set_key("video_device", str(qr_combo.itemData(x).toString()), True)
        qr_combo.currentIndexChanged.connect(on_video_device)
        widgets.append((qr_label, qr_combo, qr_help))

        usechange_cb = QCheckBox(_('Use change addresses'))
        usechange_cb.setChecked(self.wallet.use_change)
        usechange_help = HelpButton(_('Using change addresses makes it more difficult for other people to track your transactions.'))
        if not self.config.is_modifiable('use_change'): usechange_cb.setEnabled(False)
        def on_usechange(x):
            usechange_result = x == Qt.Checked
            if self.wallet.use_change != usechange_result:
                self.wallet.use_change = usechange_result
                self.wallet.storage.put('use_change', self.wallet.use_change)
        usechange_cb.stateChanged.connect(on_usechange)
        widgets.append((usechange_cb, None, usechange_help))

        showtx_cb = QCheckBox(_('Show transaction before broadcast'))
        showtx_cb.setChecked(self.config.get('show_before_broadcast', False))
        showtx_cb.stateChanged.connect(lambda x: self.config.set_key('show_before_broadcast', showtx_cb.isChecked()))
        showtx_help = HelpButton(_('Display the details of your transactions before broadcasting it.'))
        widgets.append((showtx_cb, None, showtx_help))

        can_edit_fees_cb = QCheckBox(_('Set transaction fees manually'))
        can_edit_fees_cb.setChecked(self.config.get('can_edit_fees', False))
        def on_editfees(x):
            self.config.set_key('can_edit_fees', x == Qt.Checked)
            self.update_fee_edit()
        can_edit_fees_cb.stateChanged.connect(on_editfees)
        can_edit_fees_help = HelpButton(_('This option lets you edit fees in the send tab.'))
        widgets.append((can_edit_fees_cb, None, can_edit_fees_help))

        for a,b,c in widgets:
            i = grid.rowCount()
            if b:
                grid.addWidget(a, i, 0)
                grid.addWidget(b, i, 1)
            else:
                grid.addWidget(a, i, 0, 1, 2)
            grid.addWidget(c, i, 2)

        vbox.addLayout(grid)
        vbox.addStretch(1)
        vbox.addLayout(close_button(d))
        d.setLayout(vbox)

        # run the dialog
        d.exec_()

        run_hook('close_settings_dialog')
        if self.need_restart:
            QMessageBox.warning(self, _('Success'), _('Please restart Electrum to activate the new GUI settings'), _('OK'))



    def run_network_dialog(self):
        if not self.network:
            QMessageBox.warning(self, _('Offline'), _('You are using Electrum in offline mode.\nRestart Electrum if you want to get connected.'), _('OK'))
            return
        NetworkDialog(self.wallet.network, self.config, self).do_exec()

    def closeEvent(self, event):
        self.config.set_key("is_maximized", self.isMaximized())
        if not self.isMaximized():
            g = self.geometry()
            self.config.set_key("winpos-qt", [g.left(),g.top(),g.width(),g.height()])
        self.save_column_widths()
        self.config.set_key("console-history", self.console.history[-50:], True)
        self.wallet.storage.put('accounts_expanded', self.accounts_expanded)
        event.accept()


    def plugins_dialog(self):
        from electrum.plugins import plugins

        self.pluginsdialog = d = QDialog(self)
        d.setWindowTitle(_('Electrum Plugins'))
        d.setModal(1)

        vbox = QVBoxLayout(d)

        # plugins
        scroll = QScrollArea()
        scroll.setEnabled(True)
        scroll.setWidgetResizable(True)
        scroll.setMinimumSize(400,250)
        vbox.addWidget(scroll)

        w = QWidget()
        scroll.setWidget(w)
        w.setMinimumHeight(len(plugins)*35)

        grid = QGridLayout()
        grid.setColumnStretch(0,1)
        w.setLayout(grid)

        def do_toggle(cb, p, w):
            if p.is_enabled():
                if p.disable():
                    p.close()
            else:
                if p.enable():
                    p.load_wallet(self.wallet)
                    p.init_qt(self.gui_object)
            r = p.is_enabled()
            cb.setChecked(r)
            if w: w.setEnabled(r)

        def mk_toggle(cb, p, w):
            return lambda: do_toggle(cb,p,w)

        for i, p in enumerate(plugins):
            try:
                cb = QCheckBox(p.fullname())
                cb.setDisabled(not p.is_available())
                cb.setChecked(p.is_enabled())
                grid.addWidget(cb, i, 0)
                if p.requires_settings():
                    w = p.settings_widget(self)
                    w.setEnabled( p.is_enabled() )
                    grid.addWidget(w, i, 1)
                else:
                    w = None
                cb.clicked.connect(mk_toggle(cb,p,w))
                grid.addWidget(HelpButton(p.description()), i, 2)
            except Exception:
                print_msg("Error: cannot display plugin", p)
                traceback.print_exc(file=sys.stdout)
        grid.setRowStretch(i+1,1)
        vbox.addLayout(close_button(d))
        d.exec_()

    def show_account_details(self, k):
        account = self.wallet.accounts[k]

        d = QDialog(self)
        d.setWindowTitle(_('Account Details'))
        d.setModal(1)

        vbox = QVBoxLayout(d)
        name = self.wallet.get_account_name(k)
        label = QLabel('Name: ' + name)
        vbox.addWidget(label)

        vbox.addWidget(QLabel(_('Address type') + ': ' + account.get_type()))

        vbox.addWidget(QLabel(_('Derivation') + ': ' + k))

        vbox.addWidget(QLabel(_('Master Public Key:')))

        text = QTextEdit()
        text.setReadOnly(True)
        text.setMaximumHeight(170)
        vbox.addWidget(text)

        mpk_text = '\n'.join( account.get_master_pubkeys() )
        text.setText(mpk_text)

        vbox.addLayout(close_button(d))
        d.exec_()
