Improve 'send all coins' function:

* do use coin chooser when sending all coins (fixes #2000)
* allow "!" syntax for multiple outputs (fixes #1698)

gui/qt/main_window.py

@@ -994,27 +994,14 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         vbox.addWidget(self.invoices_label)
         vbox.addWidget(self.invoice_list)
         vbox.setStretchFactor(self.invoice_list, 1000)
-
         # Defer this until grid is parented to avoid ugly flash during startup
         self.update_fee_edit()
-
         run_hook('create_send_tab', grid)
         return w
 
-
     def spend_max(self):
-        inputs = self.get_coins()
-        sendable = sum(map(lambda x:x['value'], inputs))
-        fee = self.fee_e.get_amount() if self.fee_e.isModified() else None
-        r = self.get_payto_or_dummy()
-        amount, fee = self.wallet.get_max_amount(self.config, inputs, r, fee)
-        if not self.fee_e.isModified():
-            self.fee_e.setAmount(fee)
-        self.amount_e.setAmount(amount)
-        self.not_enough_funds = (fee + amount > sendable)
-        # emit signal for fiat_amount update
-        self.amount_e.textEdited.emit("")
         self.is_max = True
+        self.do_update_fee()
 
     def reset_max(self):
         self.is_max = False
@@ -1034,14 +1021,14 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         '''
         freeze_fee = (self.fee_e.isModified()
                       and (self.fee_e.text() or self.fee_e.hasFocus()))
-        amount = self.amount_e.get_amount()
+        amount = '!' if self.is_max else self.amount_e.get_amount()
         if amount is None:
             if not freeze_fee:
                 self.fee_e.setAmount(None)
             self.not_enough_funds = False
         else:
             fee = self.fee_e.get_amount() if freeze_fee else None
-            outputs = self.payto_e.get_outputs()
+            outputs = self.payto_e.get_outputs(self.is_max)
             if not outputs:
                 _type, addr = self.get_payto_or_dummy()
                 outputs = [(_type, addr, amount)]
@@ -1054,6 +1041,12 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
                 fee = None if self.not_enough_funds else self.wallet.get_tx_fee(tx)
                 self.fee_e.setAmount(fee)
 
+            if self.is_max:
+                amount = tx.output_value()
+                self.amount_e.setAmount(amount)
+                self.amount_e.textEdited.emit("")
+
+
     def update_fee_edit(self):
         b = self.config.get('dynamic_fees', True)
         self.fee_slider.setVisible(b)
@@ -1132,7 +1125,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
             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()
+            outputs = self.payto_e.get_outputs(self.is_max)
 
             if self.payto_e.is_alias and self.payto_e.validated is False:
                 alias = self.payto_e.toPlainText()
@@ -1174,7 +1167,6 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         if not r:
             return
         outputs, fee, tx_desc, coins = r
-        amount = sum(map(lambda x:x[2], outputs))
         try:
             tx = self.wallet.make_unsigned_transaction(coins, outputs, self.config, fee)
         except NotEnoughFunds:
@@ -1185,6 +1177,8 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
             self.show_message(str(e))
             return
 
+        amount = tx.output_value() if self.is_max else sum(map(lambda x:x[2], outputs))
+
         use_rbf = self.rbf_checkbox.isChecked()
         if use_rbf:
             tx.set_sequence(0)

gui/qt/paytoedit.py

@@ -98,6 +98,8 @@ class PayToEdit(ScanQRTextEdit):
         return script
 
     def parse_amount(self, x):
+        if x.strip() == '!':
+            return '!'
         p = pow(10, self.amount_edit.decimal_point())
         return int(p * Decimal(x.strip()))
 
@@ -138,12 +140,19 @@ class PayToEdit(ScanQRTextEdit):
                 continue
 
             outputs.append((_type, to_address, amount))
-            total += amount
+            if amount == '!':
+                self.win.is_max = True
+            else:
+                total += amount
 
         self.outputs = outputs
         self.payto_address = None
-        self.amount_edit.setAmount(total if outputs else None)
-        self.win.lock_amount(total or len(lines)>1)
+
+        if self.win.is_max:
+            self.win.do_update_fee()
+        else:
+            self.amount_edit.setAmount(total if outputs else None)
+            self.win.lock_amount(total or len(lines)>1)
 
     def get_errors(self):
         return self.errors
@@ -151,12 +160,13 @@ class PayToEdit(ScanQRTextEdit):
     def get_recipient(self):
         return self.payto_address
 
-    def get_outputs(self):
+    def get_outputs(self, is_max):
         if self.payto_address:
-            try:
+            if is_max:
+                amount = '!'
+            else:
                 amount = self.amount_edit.get_amount()
-            except:
-                amount = None
+
             _type, addr = self.payto_address
             self.outputs = [(_type, addr, amount)]