qt coin selection: allow selecting an empty set

Using this, the user can force "bump fee" not to add new inputs.

closes #5719

electrum/gui/qt/main_window.py

@@ -1475,11 +1475,18 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger):
         else:
             raise Exception('unknown invoice type')
 
-    def get_coins(self, *, nonlocal_only=False):
+    def get_coins(self, *, nonlocal_only=False) -> Sequence[PartialTxInput]:
         coins = self.get_manually_selected_coins()
-        return coins or self.wallet.get_spendable_coins(None, nonlocal_only=nonlocal_only)
+        if coins is not None:
+            return coins
+        else:
+            return self.wallet.get_spendable_coins(None, nonlocal_only=nonlocal_only)
 
-    def get_manually_selected_coins(self) -> Sequence[PartialTxInput]:
+    def get_manually_selected_coins(self) -> Optional[Sequence[PartialTxInput]]:
+        """Return a list of selected coins or None.
+        Note: None means selection is not being used,
+              while an empty sequence means the user specifically selected that.
+        """
         return self.utxo_list.get_spend_list()
 
     def pay_onchain_dialog(self, inputs: Sequence[PartialTxInput],
@@ -2009,7 +2016,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger):
         self.coincontrol_label.setTextInteractionFlags(Qt.TextSelectableByMouse)
         sb.addWidget(self.coincontrol_label)
 
-        clear_cc_button = EnterButton(_('Reset'), lambda: self.utxo_list.set_spend_list([]))
+        clear_cc_button = EnterButton(_('Reset'), lambda: self.utxo_list.set_spend_list(None))
         clear_cc_button.setStyleSheet("margin-right: 5px;")
         sb.addPermanentWidget(clear_cc_button)
 

electrum/gui/qt/transaction_dialog.py

@@ -450,9 +450,9 @@ class BaseTxDialog(QDialog, MessageBoxMixin):
     def update_io(self):
         inputs_header_text = _("Inputs") + ' (%d)'%len(self.tx.inputs())
         if not self.finalized:
-            num_utxos = len(self.main_window.get_manually_selected_coins())
-            if num_utxos > 0:
-                inputs_header_text += f"  -  " + _("Coin selection active ({} UTXOs selected)").format(num_utxos)
+            selected_coins = self.main_window.get_manually_selected_coins()
+            if selected_coins is not None:
+                inputs_header_text += f"  -  " + _("Coin selection active ({} UTXOs selected)").format(len(selected_coins))
         self.inputs_header.setText(inputs_header_text)
         ext = QTextCharFormat()
         rec = QTextCharFormat()

electrum/gui/qt/utxo_list.py

@@ -58,7 +58,7 @@ class UTXOList(MyTreeView):
         super().__init__(parent, self.create_menu,
                          stretch_column=self.Columns.LABEL,
                          editable_columns=[])
-        self._spend_set = set()  # type: Set[str]  # coins selected by the user to spend from
+        self._spend_set = None  # type: Optional[Set[str]]  # coins selected by the user to spend from
         self.setModel(QStandardItemModel(self))
         self.setSelectionMode(QAbstractItemView.ExtendedSelection)
         self.setSortingEnabled(True)
@@ -75,12 +75,12 @@ class UTXOList(MyTreeView):
             self.insert_utxo(idx, utxo)
         self.filter()
         # update coincontrol status bar
-        coins = [self.utxo_dict[x] for x in self._spend_set] or utxos
+        if self._spend_set is not None:
+            coins = [self.utxo_dict[x] for x in self._spend_set]
             coins = self._filter_frozen_coins(coins)
             amount = sum(x.value_sats() for x in coins)
             amount_str = self.parent.format_amount_and_units(amount)
             num_outputs_str = _("{} outputs available ({} total)").format(len(coins), len(utxos))
-        if self._spend_set:
             self.parent.set_coincontrol_msg(_("Coin control active") + f': {num_outputs_str}, {amount_str}')
         else:
             self.parent.set_coincontrol_msg(None)
@@ -101,7 +101,7 @@ class UTXOList(MyTreeView):
         utxo_item[self.Columns.OUTPOINT].setFont(QFont(MONOSPACE_FONT))
         utxo_item[self.Columns.ADDRESS].setData(name, Qt.UserRole)
         SELECTED_TO_SPEND_TOOLTIP = _('Coin selected to be spent')
-        if name in self._spend_set:
+        if name in (self._spend_set or set()):
             for col in utxo_item:
                 col.setBackground(ColorScheme.GREEN.as_color(True))
                 if col != self.Columns.OUTPOINT:
@@ -113,7 +113,7 @@ class UTXOList(MyTreeView):
             utxo_item[self.Columns.OUTPOINT].setBackground(ColorScheme.BLUE.as_color(True))
             utxo_item[self.Columns.OUTPOINT].setToolTip(f"{name}\n{_('Coin is frozen')}")
         else:
-            tooltip = ("\n" + SELECTED_TO_SPEND_TOOLTIP) if name in self._spend_set else ""
+            tooltip = ("\n" + SELECTED_TO_SPEND_TOOLTIP) if name in (self._spend_set or set()) else ""
             utxo_item[self.Columns.OUTPOINT].setToolTip(name + tooltip)
         self.model().insertRow(idx, utxo_item)
 
@@ -121,8 +121,6 @@ class UTXOList(MyTreeView):
         if not self.model():
             return None
         items = self.selected_in_column(self.Columns.ADDRESS)
-        if not items:
-            return None
         return [x.data(Qt.UserRole) for x in items]
 
     def _filter_frozen_coins(self, coins: List[PartialTxInput]) -> List[PartialTxInput]:
@@ -131,29 +129,39 @@ class UTXOList(MyTreeView):
                      not self.wallet.is_frozen_coin(utxo))]
         return coins
 
-    def set_spend_list(self, coins: List[PartialTxInput]):
+    def set_spend_list(self, coins: Optional[List[PartialTxInput]]):
+        if coins is not None:
             coins = self._filter_frozen_coins(coins)
             self._spend_set = {utxo.prevout.to_str() for utxo in coins}
+        else:
+            self._spend_set = None
         self.update()
 
-    def get_spend_list(self) -> Sequence[PartialTxInput]:
+    def get_spend_list(self) -> Optional[Sequence[PartialTxInput]]:
+        if self._spend_set is None:
+            return None
         return [self.utxo_dict[x] for x in self._spend_set]
 
     def _maybe_reset_spend_list(self, current_wallet_utxos: Sequence[PartialTxInput]) -> None:
+        if self._spend_set is None:
+            return
         # if we spent one of the selected UTXOs, just reset selection
         utxo_set = {utxo.prevout.to_str() for utxo in current_wallet_utxos}
         if not all([prevout_str in utxo_set for prevout_str in self._spend_set]):
-            self._spend_set = set()
+            self._spend_set = None
 
     def create_menu(self, position):
         selected = self.get_selected_outpoints()
-        if not selected:
+        if selected is None:
             return
         menu = QMenu()
         menu.setSeparatorsCollapsible(True)  # consecutive separators are merged together
         coins = [self.utxo_dict[name] for name in selected]
+        if len(coins) == 0:
+            menu.addAction(_("Spend (select none)"), lambda: self.set_spend_list(coins))
+        else:
             menu.addAction(_("Spend"), lambda: self.set_spend_list(coins))
-        assert len(coins) >= 1, len(coins)
+
         if len(coins) == 1:
             utxo = coins[0]
             addr = utxo.address
@@ -184,8 +192,7 @@ class UTXOList(MyTreeView):
                 menu.addAction(_("Address is frozen"), lambda: None).setEnabled(False)
                 menu.addAction(_("Unfreeze Address"), lambda: self.parent.set_frozen_state_of_addresses([addr], False))
                 menu.addSeparator()
-        else:
-            # multiple items selected
+        elif len(coins) > 1:  # multiple items selected
             menu.addSeparator()
             addrs = [utxo.address for utxo in coins]
             is_coin_frozen = [self.wallet.is_frozen_coin(utxo) for utxo in coins]