New feature "Scan QR code" in sending dialog.

lib/gui_qt.py

@@ -41,7 +41,7 @@ except:
     sys.exit(1)
 
 from wallet import format_satoshis
-import bmp, mnemonic, pyqrnative
+import bmp, mnemonic, pyqrnative, qrscanner
 
 from decimal import Decimal
 
@@ -443,6 +443,24 @@ class ElectrumWindow(QMainWindow):
         self.payto_e = QLineEdit()
         grid.addWidget(QLabel(_('Pay to')), 1, 0)
         grid.addWidget(self.payto_e, 1, 1, 1, 3)
+        
+        def fill_from_qr():
+            qrcode = qrscanner.scan_qr()
+            if 'address' in qrcode:
+                self.payto_e.setText(qrcode['address'])
+            if 'amount' in qrcode:
+                self.amount_e.setText(str(qrcode['amount']))
+            if 'label' in qrcode:
+                self.message_e.setText(qrcode['label'])
+            if 'message' in qrcode:
+                self.message_e.setText("%s (%s)" % (self.message_e.text(), qrcode['message']))
+                
+
+        if qrscanner.is_available():
+            b = QPushButton(_("Scan QR code"))
+            b.clicked.connect(fill_from_qr)
+            grid.addWidget(b, 1, 5)
+    
         grid.addWidget(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)')), 1, 4)
 
         completer = QCompleter()