Disconnect log signals on exit.

If we don't do this, the uvicorn server may log its shutdown after the
Qt application has closed, and the signal this attempts to emit may not
be valid. Disconnect the log signals when the application exits to
prevent that.

There's actually another solution that I thought would be better, but I
couldn't get it to work:
https://www.pyinstaller.org/en/stable/feature-notes.html#automatic-hiding-and-minimization-of-console-window-under-windows
describes a way to have pyinstaller hide or minimize the console rather
than disabling it entirely. I was never really fond of getting rid of
the console window in the first place, but it did bother some users. If
we could get the hide or minimize option working, that'd probably avoid
bothering users, but also make the logs much easier to find, get us out
of the trouble of maintaining our own log viewer, and fix the problem
mentioned in the comment I add here (the log window only works if
there's only one in memory log handler).

Another option would be ditching our log window and instead just having
that menu item open the log file or directory in whatever program the OS
defaults to (probably notepad). It would still have the quirk of maybe
needing to open more than one location, since logging is use
configurable.

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/3278.

qt_ui/logging_handler.py

@@ -1,5 +1,8 @@
+from __future__ import annotations
+
 import logging
 import typing
+from collections.abc import Iterator
 
 LogHook = typing.Callable[[str], None]
 
@@ -15,6 +18,16 @@ class HookableInMemoryHandler(logging.Handler):
         self._log = ""
         self._hook = None
 
+    @staticmethod
+    def iter_registered_handlers(
+        logger: logging.Logger | None = None,
+    ) -> Iterator[HookableInMemoryHandler]:
+        if logger is None:
+            logger = logging.getLogger()
+        for handler in logger.handlers:
+            if isinstance(handler, HookableInMemoryHandler):
+                yield handler
+
     @property
     def log(self) -> str:
         return self._log

qt_ui/windows/QLiberationWindow.py

@@ -27,6 +27,7 @@ from game.theater import ControlPoint, MissionTarget, TheaterGroundObject
 from game.turnstate import TurnState
 from qt_ui import liberation_install
 from qt_ui.dialogs import Dialog
+from qt_ui.logging_handler import HookableInMemoryHandler
 from qt_ui.models import GameModel
 from qt_ui.simcontroller import SimController
 from qt_ui.uiflags import UiFlags
@@ -576,6 +577,10 @@ class QLiberationWindow(QMainWindow):
         self._cp_dialog = QBaseMenu2(None, cp, self.game_model)
         self._cp_dialog.show()
 
+    def _disconnect_log_signals(self) -> None:
+        for handler in HookableInMemoryHandler.iter_registered_handlers():
+            handler.clearHook()
+
     def _qsettings(self) -> QSettings:
         return QSettings("DCS Liberation", "Qt UI")
 
@@ -597,6 +602,7 @@ class QLiberationWindow(QMainWindow):
             QMessageBox.Yes | QMessageBox.No,
         )
         if result == QMessageBox.Yes:
+            self._disconnect_log_signals()
             self._save_window_geometry()
             super().closeEvent(event)
             self.dialog = None

qt_ui/windows/logs/QLogsWindow.py

@@ -1,14 +1,13 @@
-import logging
 import typing
 
 from PySide6.QtCore import Signal
+from PySide6.QtGui import QTextCursor, QIcon
 from PySide6.QtWidgets import (
     QDialog,
     QPlainTextEdit,
     QVBoxLayout,
     QPushButton,
 )
-from PySide6.QtGui import QTextCursor, QIcon
 
 from qt_ui.logging_handler import HookableInMemoryHandler
 
@@ -50,12 +49,17 @@ class QLogsWindow(QDialog):
 
         self.appendLogSignal.connect(self.appendLog)
 
+        try:
+            # This assumes that there's never more than one in memory handler. We don't
+            # configure more than one by default, but logging is customizable with
+            # resources/logging.yaml. If someone adds a second in-memory handler, only
+            # the first one (in arbitrary order) will be shown.
+            self._logging_handler = next(
+                HookableInMemoryHandler.iter_registered_handlers()
+            )
+        except StopIteration:
             self._logging_handler = None
-        logger = logging.getLogger()
-        for handler in logger.handlers:
-            if isinstance(handler, HookableInMemoryHandler):
-                self._logging_handler = handler
-                break
+
         if self._logging_handler is not None:
             self.textbox.setPlainText(self._logging_handler.log)
             self.textbox.moveCursor(QTextCursor.End)