qml: make finalizer options a flag, allowing to enable/disable certain finalizer options

depending on the use-case

Author: accumulator

electrum/gui/qml/components/ConfirmTxDialog.qml

@@ -14,7 +14,6 @@ ElDialog {
     required property var satoshis  // type: Amount
     property string address
     property string message
-    property bool showOptions: true
     property alias amountLabelText: amountLabel.text
     property alias sendButtonText: sendButton.text
 
@@ -152,7 +151,7 @@ ElDialog {
                     Layout.columnSpan: 2
                     labelText: qsTr('Options')
                     color: Material.accentColor
-                    visible: showOptions
+                    visible: finalizer.txOptions
                 }
 
                 DialogHighlightPane {
@@ -168,7 +167,9 @@ ElDialog {
                         rowSpacing: 0
 
                         ElCheckBox {
+                            id: cb_multiple_change
                             Layout.fillWidth: true
+                            visible: finalizer.txOptions & TxFinalizer.TxOptions.MULTIPLE_CHANGE
                             text: qsTr('Use multiple change addresses')
                             onCheckedChanged: {
                                 if (activeFocus) {
@@ -182,13 +183,16 @@ ElDialog {
                         }
 
                         HelpButton {
+                            visible: cb_multiple_change.visible
                             heading: qsTr('Use multiple change addresses')
                             helptext: [qsTr('In some cases, use up to 3 change addresses in order to break up large coin amounts and obfuscate the recipient address.'),
                                        qsTr('This may result in higher transactions fees.')].join(' ')
                         }
 
                         ElCheckBox {
+                            id: cb_output_rounding
                             Layout.fillWidth: true
+                            visible: finalizer.txOptions & TxFinalizer.TxOptions.OUTPUT_ROUNDING
                             text: Config.shortDescFor('WALLET_COIN_CHOOSER_OUTPUT_ROUNDING')
                             onCheckedChanged: {
                                 if (activeFocus) {
@@ -202,14 +206,16 @@ ElDialog {
                         }
 
                         HelpButton {
+                            visible: cb_output_rounding.visible
                             heading: Config.shortDescFor('WALLET_COIN_CHOOSER_OUTPUT_ROUNDING')
                             helptext: Config.longDescFor('WALLET_COIN_CHOOSER_OUTPUT_ROUNDING')
                         }
 
                         ElCheckBox {
                             id: cb_send_change_to_lightning
                             Layout.fillWidth: true
-                            visible: Daemon.currentWallet.isLightning && Daemon.currentWallet.lightningCanReceive.satsInt > 0
+                            visible: finalizer.txOptions & TxFinalizer.TxOptions.SEND_CHANGE_TO_LIGHTNING
+                                && Daemon.currentWallet.isLightning && Daemon.currentWallet.lightningCanReceive.satsInt > 0
                             text: Config.shortDescFor('WALLET_SEND_CHANGE_TO_LIGHTNING')
                             onCheckedChanged: {
                                 if (activeFocus) {
@@ -223,7 +229,7 @@ ElDialog {
                         }
 
                         HelpButton {
-                            visible: Daemon.currentWallet.isLightning && Daemon.currentWallet.lightningCanReceive.satsInt > 0
+                            visible: cb_send_change_to_lightning.visible
                             heading: Config.shortDescFor('WALLET_SEND_CHANGE_TO_LIGHTNING')
                             helptext: Config.longDescFor('WALLET_SEND_CHANGE_TO_LIGHTNING')
                         }

electrum/gui/qml/components/WalletMainView.qml

@@ -144,7 +144,6 @@ Item {
             var finalizerDialog = confirmSweepDialog.createObject(mainView, {
                 privateKeys: dialog.privateKeys,
                 message: qsTr('Sweep transaction'),
-                showOptions: false,
                 amountLabelText: qsTr('Total sweep amount'),
                 sendButtonText: Daemon.currentWallet.isWatchOnly
                     ? qsTr('Sweep...')
@@ -679,6 +678,9 @@ Item {
                 property var _swapwaitdialog
                 wallet: Daemon.currentWallet
                 canRbf: true
+                txOptions: TxFinalizer.TxOptions.MULTIPLE_CHANGE
+                    | TxFinalizer.TxOptions.OUTPUT_ROUNDING
+                    | TxFinalizer.TxOptions.SEND_CHANGE_TO_LIGHTNING
                 onFinished: (signed, saved, complete) => {
                     if (!complete) {
                         var msg
@@ -760,6 +762,7 @@ Item {
                 wallet: Daemon.currentWallet
                 canRbf: true
                 privateKeys: _confirmSweepDialog.privateKeys
+                txOptions: TxFinalizer.TxOptions.NONE
             }
 
             onClosed: destroy()

electrum/gui/qml/qechannelopener.py

@@ -216,6 +216,7 @@ def openChannel(self, confirm_backup_conflict=False):
 
         self._finalizer = QETxFinalizer(self, make_tx=mktx, accept=acpt)
         self._finalizer.canRbf = False
+        self._finalizer.txOptions = QETxFinalizer.TxOptions.MULTIPLE_CHANGE | QETxFinalizer.TxOptions.OUTPUT_ROUNDING
         self._finalizer.amount = self._amount
         self._finalizer.wallet = self._wallet
         self.finalizerChanged.emit()

electrum/gui/qml/qetxfinalizer.py

@@ -1,7 +1,7 @@
 import asyncio
 import copy
 from asyncio import Future
-from enum import IntEnum
+from enum import IntEnum, IntFlag
 import threading
 from decimal import Decimal
 from typing import Optional, TYPE_CHECKING, Callable
@@ -163,9 +163,19 @@ def update(self):
 
 
 class TxFeeSlider(FeeSlider):
+
+    @pyqtEnum
+    class TxOptions(IntFlag):
+        NONE = 0
+        MULTIPLE_CHANGE = 1
+        OUTPUT_ROUNDING = 2
+        SEND_CHANGE_TO_LIGHTNING = 4
+
     def __init__(self, parent=None):
         FeeSlider.__init__(self, parent)
 
+        self._tx_options = TxFeeSlider.TxOptions.MULTIPLE_CHANGE | TxFeeSlider.TxOptions.OUTPUT_ROUNDING
+
         self._fee = QEAmount()
         self._feeRate = ''
         self._userFee = ''
@@ -179,6 +189,20 @@ def __init__(self, parent=None):
         self._valid = False
         self._warning = ''
 
+    txOptionsChanged = pyqtSignal()
+    @pyqtProperty(int, notify=txOptionsChanged)
+    def txOptions(self) -> int:
+        return int(self._tx_options)
+
+    @txOptions.setter
+    def txOptions(self, options: int):
+        options = TxFeeSlider.TxOptions(options)
+        if self._tx_options != options:
+            self._tx_options = options
+            self.txOptionsChanged.emit()
+            if self._wallet:  # recompute (e.g. swap message) for the new option set
+                self.update()
+
     feeChanged = pyqtSignal()
     @pyqtProperty(QVariant, notify=feeChanged)
     def fee(self) -> QEAmount:
@@ -504,6 +528,13 @@ def swapStatusMsg(self, swap_status_msg: str):
             self._swapStatusMsg = swap_status_msg
             self.swapStatusMsgChanged.emit()
 
+    def _send_change_to_lightning(self) -> bool:
+        # only honour the (persistent) config flag when this finalizer was set up to
+        # offer the option, so non-payment flows (channel open, sweep) never swap change
+        return (bool(self._tx_options & TxFeeSlider.TxOptions.SEND_CHANGE_TO_LIGHTNING)
+                and self._wallet.wallet.has_lightning()
+                and self._config.WALLET_SEND_CHANGE_TO_LIGHTNING)
+
     @profiler
     def make_tx(self, amount):
         self._logger.debug(f'make_tx amount={amount}')
@@ -519,7 +550,7 @@ def make_tx(self, amount):
                 outputs=outputs,
                 fee_policy=self._fee_policy,
                 rbf=self._rbf,
-                send_change_to_lightning=self._config.WALLET_SEND_CHANGE_TO_LIGHTNING)
+                send_change_to_lightning=self._send_change_to_lightning())
 
         self._logger.debug('fee: %d, inputs: %d, outputs: %d' % (tx.get_fee(), len(tx.inputs()), len(tx.outputs())))
 
@@ -530,7 +561,8 @@ def update(self):
             self._logger.debug('wallet not set, ignoring update()')
             return
 
-        if self._wallet.wallet.has_lightning() and self._config.WALLET_SEND_CHANGE_TO_LIGHTNING:
+        send_change_to_lightning = self._send_change_to_lightning()
+        if send_change_to_lightning:
             self._logger.debug('sending change to lightning')
             self.prepare_swap_transport()
 
@@ -539,7 +571,7 @@ def update(self):
             amount = '!' if self._amount.isMax else self._amount.satsInt
             tx = self.make_tx(amount=amount)
             msg = ''
-            if self.config.WALLET_SEND_CHANGE_TO_LIGHTNING:
+            if send_change_to_lightning:
                 msg = self.swap_manager.get_message_for_swap_change(self.swap_transport, tx)
             self.swapStatusMsg = msg