add NotEnoughFunds exception

gui/gtk.py

@@ -680,19 +680,22 @@ class ElectrumWindow:
         self.user_fee = False
 
         def entry_changed( entry, is_fee ):
-            self.funds_error = False
             amount = numbify(amount_entry)
             fee = numbify(fee_entry)
             if not is_fee: fee = None
             if amount is None:
                 return
-            tx = self.wallet.make_unsigned_transaction([('op_return', 'dummy_tx', amount)], fee)
-            if not is_fee:
-                if tx:
+            try:
+                tx = self.wallet.make_unsigned_transaction([('op_return', 'dummy_tx', amount)], fee)
+                self.funds_error = False
+            except NotEnoughFunds:
+                self.funds_error = True
+
+            if not self.funds_error:
+                if not is_fee:
                     fee = tx.get_fee()
                     fee_entry.set_text( str( Decimal( fee ) / 100000000 ) )
                     self.fee_box.show()
-            if tx:
                 amount_entry.modify_text(Gtk.StateType.NORMAL, Gdk.color_parse("#000000"))
                 fee_entry.modify_text(Gtk.StateType.NORMAL, Gdk.color_parse("#000000"))
                 send_button.set_sensitive(True)
@@ -700,7 +703,6 @@ class ElectrumWindow:
                 send_button.set_sensitive(False)
                 amount_entry.modify_text(Gtk.StateType.NORMAL, Gdk.color_parse("#cc0000"))
                 fee_entry.modify_text(Gtk.StateType.NORMAL, Gdk.color_parse("#cc0000"))
-                self.funds_error = True
 
         amount_entry.connect('changed', entry_changed, False)
         fee_entry.connect('changed', entry_changed, True)        

gui/qt/main_window.py

@@ -35,7 +35,7 @@ from electrum.plugins import run_hook
 
 import icons_rc
 
-from electrum.util import format_satoshis
+from electrum.util import format_satoshis, NotEnoughFunds
 from electrum import Transaction
 from electrum import mnemonic
 from electrum import util, bitcoin, commands, Interface, Wallet
@@ -953,10 +953,13 @@ class ElectrumWindow(QMainWindow):
                 if not outputs:
                     addr = self.payto_e.payto_address if self.payto_e.payto_address else self.dummy_address
                     outputs = [('address', addr, amount)]
-                tx = self.wallet.make_unsigned_transaction(outputs, fee, coins = self.get_coins())
-                self.not_enough_funds = (tx is None)
+                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 = self.wallet.get_tx_fee(tx) if tx else None
+                    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))

lib/util.py

@@ -4,6 +4,7 @@ import shutil
 from datetime import datetime
 is_verbose = False
 
+class NotEnoughFunds(Exception): pass
 
 class MyEncoder(json.JSONEncoder):
     def default(self, obj):

lib/wallet.py

@@ -27,7 +27,7 @@ import math
 import json
 import copy
 
-from util import print_msg, print_error
+from util import print_msg, print_error, NotEnoughFunds
 
 from bitcoin import *
 from account import *
@@ -712,8 +712,9 @@ class Abstract_Wallet(object):
             fee = fixed_fee if fixed_fee is not None else self.estimated_fee(tx)
             if total >= amount + fee: break
         else:
-            print_error("Not enough funds", total, amount, fee)
-            return None
+            raise NotEnoughFunds()
+            #print_error("Not enough funds", total, amount, fee)
+            #return None
 
         # change address
         if not change_addr: