logging: expose 'disablefilelogging' option in Qt preferences

electrum/commands.py

@@ -941,7 +941,7 @@ def add_global_options(parser):
     group.add_argument("--testnet", action="store_true", dest="testnet", default=False, help="Use Testnet")
     group.add_argument("--regtest", action="store_true", dest="regtest", default=False, help="Use Regtest")
     group.add_argument("--simnet", action="store_true", dest="simnet", default=False, help="Use Simnet")
-    group.add_argument("--disablefilelogging", action="store_true", dest="disablefilelogging", default=False, help="Do not log to file")
+    group.add_argument("--disablefilelogging", action="store_true", dest="disablefilelogging", default=None, help="Do not log to file")
 
 def get_parser():
     # create main parser

electrum/gui/qt/main_window.py

@@ -3005,6 +3005,14 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger):
         updatecheck_cb.stateChanged.connect(on_set_updatecheck)
         gui_widgets.append((updatecheck_cb, None))
 
+        filelogging_cb = QCheckBox(_("Write logs to file"))
+        filelogging_cb.setChecked(not self.config.get('disablefilelogging', False))
+        def on_set_filelogging(v):
+            self.config.set_key('disablefilelogging', v == Qt.Unchecked, save=True)
+        filelogging_cb.stateChanged.connect(on_set_filelogging)
+        filelogging_cb.setToolTip(_('Debug logs can be persisted to disk. These are useful for troubleshooting.'))
+        gui_widgets.append((filelogging_cb, None))
+
         usechange_cb = QCheckBox(_('Use change addresses'))
         usechange_cb.setChecked(self.wallet.use_change)
         if not self.config.is_modifiable('use_change'): usechange_cb.setEnabled(False)