also unregister callbacks from qewallet and qechannellistmodel on destroy

electrum/gui/qml/qechannellistmodel.py

@@ -4,7 +4,7 @@ from PyQt5.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, QObject
 from PyQt5.QtCore import Qt, QAbstractListModel, QModelIndex
 
 from electrum.logging import get_logger
-from electrum.util import Satoshis, register_callback
+from electrum.util import Satoshis, register_callback, unregister_callback
 from electrum.lnutil import LOCAL, REMOTE
 
 from .qetypes import QEAmount
@@ -36,6 +36,7 @@ class QEChannelListModel(QAbstractListModel):
         # methods of this class only, and specifically not be
         # partials, lambdas or methods of subobjects.  Hence...
         register_callback(self.on_network, interests)
+        self.destroyed.connect(lambda: self.on_destroy())
 
     def on_network(self, event, *args):
         if event == 'channel':
@@ -56,6 +57,8 @@ class QEChannelListModel(QAbstractListModel):
         else:
             self._logger.debug('unhandled event %s: %s' % (event, repr(args)))
 
+    def on_destroy(self):
+        unregister_callback(self.on_network)
 
     def rowCount(self, index):
         return len(self.channels)

electrum/gui/qml/qewallet.py

@@ -7,7 +7,8 @@ import threading
 from PyQt5.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, QObject, QUrl, QTimer
 
 from electrum.i18n import _
-from electrum.util import register_callback, Satoshis, format_time, parse_max_spend, InvalidPassword
+from electrum.util import (register_callback, unregister_callback,
+                           Satoshis, format_time, parse_max_spend, InvalidPassword)
 from electrum.logging import get_logger
 from electrum.wallet import Wallet, Abstract_Wallet
 from electrum.storage import StorageEncryptionVersion
@@ -86,6 +87,7 @@ class QEWallet(AuthMixin, QObject):
         # methods of this class only, and specifically not be
         # partials, lambdas or methods of subobjects.  Hence...
         register_callback(self.on_network, interests)
+        self.destroyed.connect(lambda: self.on_destroy())
 
     @pyqtProperty(bool, notify=isUptodateChanged)
     def isUptodate(self):
@@ -154,6 +156,8 @@ class QEWallet(AuthMixin, QObject):
         else:
             self._logger.debug('unhandled event: %s %s' % (event, str(args)))
 
+    def on_destroy(self):
+        unregister_callback(self.on_network)
 
     def add_tx_notification(self, tx):
         self._logger.debug('new transaction event')