qml: first part of partially signing tx while not having txid yet

electrum/gui/qml/components/TxDetails.qml

@@ -448,7 +448,7 @@ Pane {
             onAccepted: {
                 root.rawtx = rbffeebumper.getNewTx()
                 if (txdetails.wallet.canSignWithoutCosigner) {
-                    txdetails.sign_and_broadcast()
+                    txdetails.signAndBroadcast()
                 } else {
                     var dialog = app.messageDialog.createObject(app, {
                         title: qsTr('Transaction fee updated.'),
@@ -475,7 +475,7 @@ Pane {
                 // replaces parent tx with cpfp tx
                 root.rawtx = cpfpfeebumper.getNewTx()
                 if (txdetails.wallet.canSignWithoutCosigner) {
-                    txdetails.sign_and_broadcast()
+                    txdetails.signAndBroadcast()
                 } else {
                     var dialog = app.messageDialog.createObject(app, {
                         title: qsTr('CPFP fee bump transaction created.'),
@@ -501,7 +501,7 @@ Pane {
             onAccepted: {
                 root.rawtx = txcanceller.getNewTx()
                 if (txdetails.wallet.canSignWithoutCosigner) {
-                    txdetails.sign_and_broadcast()
+                    txdetails.signAndBroadcast()
                 } else {
                     var dialog = app.messageDialog.createObject(app, {
                         title: qsTr('Cancel transaction created.'),

electrum/gui/qml/qetxdetails.py

@@ -310,7 +310,7 @@ class QETxDetails(QObject, QtEventListener):
         self._short_id = tx_mined_info.short_id() or ""
 
     @pyqtSlot()
-    def sign_and_broadcast(self):
+    def signAndBroadcast(self):
         self._sign(broadcast=True)
 
     @pyqtSlot()
@@ -320,20 +320,24 @@ class QETxDetails(QObject, QtEventListener):
     def _sign(self, broadcast):
         # TODO: connecting/disconnecting signal handlers here is hmm
         try:
-            self._wallet.transactionSigned.disconnect(self.onSigned)
-            self._wallet.broadcastSucceeded.disconnect(self.onBroadcastSucceeded)
             if broadcast:
+                self._wallet.broadcastSucceeded.disconnect(self.onBroadcastSucceeded)
                 self._wallet.broadcastfailed.disconnect(self.onBroadcastFailed)
         except:
             pass
-        self._wallet.transactionSigned.connect(self.onSigned)
-        self._wallet.broadcastSucceeded.connect(self.onBroadcastSucceeded)
+
         if broadcast:
+            self._wallet.broadcastSucceeded.connect(self.onBroadcastSucceeded)
             self._wallet.broadcastFailed.connect(self.onBroadcastFailed)
-        self._wallet.sign(self._tx, broadcast=broadcast)
+
+        self._wallet.sign(self._tx, broadcast=broadcast, on_success=self.on_signed_tx)
         # side-effect: signing updates self._tx
         # we rely on this for broadcast
 
+    def on_signed_tx(self, tx: Transaction):
+        self._logger.debug('on_signed_tx')
+        self.update()
+
     @pyqtSlot()
     def broadcast(self):
         assert self._tx.is_complete()
@@ -349,15 +353,6 @@ class QETxDetails(QObject, QtEventListener):
 
         self._wallet.broadcast(self._tx)
 
-    @pyqtSlot(str)
-    def onSigned(self, txid):
-        if txid != self._txid:
-            return
-
-        self._logger.debug('onSigned')
-        self._wallet.transactionSigned.disconnect(self.onSigned)
-        self.update()
-
     @pyqtSlot(str)
     def onBroadcastSucceeded(self, txid):
         if txid != self._txid:

electrum/gui/qml/qetxfinalizer.py

@@ -5,7 +5,7 @@ from PyQt5.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, QObject
 
 from electrum.logging import get_logger
 from electrum.i18n import _
-from electrum.transaction import PartialTxOutput, PartialTransaction
+from electrum.transaction import PartialTxOutput, PartialTransaction, Transaction
 from electrum.util import NotEnoughFunds, profiler
 from electrum.wallet import CannotBumpFee, CannotDoubleSpendTx, CannotCPFP
 from electrum.network import NetworkException
@@ -368,31 +368,18 @@ class QETxFinalizer(TxFeeSlider):
             self._logger.error('no valid tx')
             return
 
-        # TODO: f_accept handler not used
-        # if self.f_accept:
-        #     self.f_accept(self._tx)
-        #     return
-
-        try:
-            self._wallet.transactionSigned.disconnect(self.onSigned)
-        except:
-            pass
-        self._wallet.transactionSigned.connect(self.onSigned)
-        self._wallet.sign(self._tx)
-
-    @pyqtSlot(str)
-    def onSigned(self, txid):
-        if txid != self._tx.txid():
-            return
-
-        self._logger.debug('onSigned')
-        self._wallet.transactionSigned.disconnect(self.onSigned)
+        self._wallet.sign(self._tx, broadcast=False, on_success=self.on_signed_tx)
 
+    def on_signed_tx(self, tx: Transaction):
+        self._logger.debug('on_signed_tx')
         if not self._wallet.save_tx(self._tx):
             self._logger.error('Could not save tx')
         else:
+            # FIXME: don't rely on txid. (non-segwit tx don't have a txid
+            # until tx is complete, and can't save to backend without it).
             self.finishedSave.emit(self._tx.txid())
 
+
 # mixin for watching an existing TX based on its txid for verified event
 # requires self._wallet to contain a QEWallet instance
 # exposes txid qt property

electrum/gui/qml/qewallet.py

@@ -2,7 +2,7 @@ import asyncio
 import queue
 import threading
 import time
-from typing import TYPE_CHECKING, Optional, Tuple
+from typing import TYPE_CHECKING, Optional, Tuple, Callable
 from functools import partial
 
 from PyQt5.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, QObject, QTimer, QMetaObject, Qt
@@ -12,7 +12,7 @@ from electrum.i18n import _
 from electrum.invoices import InvoiceError, PR_DEFAULT_EXPIRATION_WHEN_CREATING, PR_PAID, PR_BROADCASTING, PR_BROADCAST
 from electrum.logging import get_logger
 from electrum.network import TxBroadcastError, BestEffortRequestFailed
-from electrum.transaction import PartialTxOutput, PartialTransaction
+from electrum.transaction import PartialTxOutput, PartialTransaction, Transaction
 from electrum.util import parse_max_spend, InvalidPassword, event_listener, AddTransactionException, get_asyncio_loop
 from electrum.plugin import run_hook
 from electrum.wallet import Multisig_Wallet
@@ -62,7 +62,8 @@ class QEWallet(AuthMixin, QObject, QtEventListener):
     paymentSucceeded = pyqtSignal([str], arguments=['key'])
     paymentFailed = pyqtSignal([str,str], arguments=['key','reason'])
     requestNewPassword = pyqtSignal()
-    transactionSigned = pyqtSignal([str], arguments=['txid'])
+    signSucceeded = pyqtSignal([str], arguments=['txid'])
+    signFailed = pyqtSignal([str], arguments=['message'])
     broadcastSucceeded = pyqtSignal([str], arguments=['txid'])
     broadcastFailed = pyqtSignal([str,str,str], arguments=['txid','code','reason'])
     saveTxSuccess = pyqtSignal([str], arguments=['txid'])
@@ -486,28 +487,37 @@ class QEWallet(AuthMixin, QObject, QtEventListener):
         self.dataChanged.emit()
 
     @auth_protect()
-    def sign(self, tx, *, broadcast: bool = False):
-        sign_hook = run_hook('tc_sign_wrapper', self.wallet, tx, partial(self.on_sign_complete, broadcast),
-                             self.on_sign_failed)
+    def sign(self, tx, *, broadcast: bool = False, on_success: Callable[[Transaction], None] = None, on_failure: Callable[[], None] = None):
+        sign_hook = run_hook('tc_sign_wrapper', self.wallet, tx, partial(self.on_sign_complete, on_success, broadcast), partial(self.on_sign_failed, on_failure))
         if sign_hook:
-            self.do_sign(tx, False)
-            self._logger.debug('plugin needs to sign tx too')
-            sign_hook(tx)
-            return
+            signSuccess = self.do_sign(tx, False)
+            if signSuccess:
+                self._logger.debug('plugin needs to sign tx too')
+                sign_hook(tx)
+                return
+        else:
+            signSuccess = self.do_sign(tx, broadcast)
 
-        self.do_sign(tx, broadcast)
+        if signSuccess:
+            if on_success: on_success(tx)
+        else:
+            if on_failure: on_failure()
 
     def do_sign(self, tx, broadcast):
-        tx = self.wallet.sign_transaction(tx, self.password)
+        try:
+            tx = self.wallet.sign_transaction(tx, self.password)
+        except BaseException as e:
+            self._logger.error(f'{e!r}')
+            self.signFailed.emit(str(e))
 
         if tx is None:
             self._logger.info('did not sign')
-            return
+            return False
 
         txid = tx.txid()
         self._logger.debug(f'do_sign(), txid={txid}')
 
-        self.transactionSigned.emit(txid)
+        self.signSucceeded.emit(txid)
 
         if not tx.is_complete():
             self._logger.debug('tx not complete')
@@ -519,14 +529,19 @@ class QEWallet(AuthMixin, QObject, QtEventListener):
             # not broadcasted, so refresh history here
             self.historyModel.init_model(True)
 
+        return True
+
     # this assumes a 2fa wallet, but there are no other tc_sign_wrapper hooks, so that's ok
-    def on_sign_complete(self, broadcast, tx):
+    def on_sign_complete(self, broadcast, cb: Callable[[Transaction], None] = None, tx: Transaction = None):
         self.otpSuccess.emit()
+        if cb: cb(tx)
         if broadcast:
             self.broadcast(tx)
 
-    def on_sign_failed(self, error):
+    # this assumes a 2fa wallet, but there are no other tc_sign_wrapper hooks, so that's ok
+    def on_sign_failed(self, cb: Callable[[], None] = None, error: str = None):
         self.otpFailed.emit('error', error)
+        if cb: cb()
 
     def request_otp(self, on_submit):
         self._otp_on_submit = on_submit