Refine Qt top-level widget lifetimes

Signed-off-by: Loren Eteval <loren.eteval@proton.me>

Furious/Window/QRCodeWindow.py

@@ -30,18 +30,10 @@ from PySide6.QtGui import *
 from PySide6.QtWidgets import *
 
 import io
-import functools
 import pyqrcode
 
 __all__ = ['QRCodeWindow']
 
-_OpenQRCodeWindows = {}
-
-
-def _releaseOpenQRCodeWindow(key, *_args):
-    """Release an exported QR-code window after Qt destroys it."""
-    _OpenQRCodeWindows.pop(key, None)
-
 
 class QRCodeWindow(AppQMainWindow):
     """Present the QR code window."""
@@ -54,28 +46,12 @@ class QRCodeWindow(AppQMainWindow):
         self.setFixedSize(640, 640)
         self.setAttribute(QtCore.Qt.WidgetAttribute.WA_DeleteOnClose, True)
 
-        self._lifetimeKey = id(self)
-        self.destroyed.connect(
-            functools.partial(_releaseOpenQRCodeWindow, self._lifetimeKey)
-        )
-
         self.tabWidget = QTabWidget(self)
         self.tabWidget.setTabsClosable(True)
         self.tabWidget.tabCloseRequested.connect(self.handleTabCloseRequested)
 
         self.setCentralWidget(self.tabWidget)
 
-    def show(self):
-        """Show and retain this unparented window until Qt destroys it."""
-        _OpenQRCodeWindows[self._lifetimeKey] = self
-
-        try:
-            return super().show()
-        except Exception:
-            _releaseOpenQRCodeWindow(self._lifetimeKey)
-
-            raise
-
     def tabCount(self) -> int:
         """Return the tab count value used by the QR code window."""
         return self.tabWidget.count()