Implement saving and restoring window state (size, position, last selected tab) using QSettings in PyQt5

frontend.py

@@ -11,7 +11,7 @@ from PyQt5.QtWidgets import (
     QComboBox, QTextEdit, QDialogButtonBox, QAction, QFileDialog, QMessageBox,
     QInputDialog, QApplication, QAbstractItemView, QSizePolicy, QHeaderView
 )
-from PyQt5.QtCore import Qt
+from PyQt5.QtCore import Qt, QSettings
 from PyQt5.QtGui import QColor, QIcon
 from backend import AnimeBackend
 
@@ -136,6 +136,7 @@ class CustomTableWidget(QTableWidget):
 class AnimeTracker(QMainWindow):
     def __init__(self):
         super().__init__()
+        self.settings = QSettings("xAI", "AnimeBacklogTracker")
         self.setWindowTitle("Anime Backlog Tracker")
         self.resize(800, 600)
         self.backend = AnimeBackend()
@@ -143,6 +144,15 @@ class AnimeTracker(QMainWindow):
         self.setCentralWidget(self.tab_widget)
         self.create_menu()
         self.load_tabs()
+        self.restoreGeometry(self.settings.value("geometry", self.saveGeometry()))
+        last_tab = self.settings.value("lastTab", None)
+        if last_tab is not None:
+            self.set_current_tab_by_identifier(last_tab)
+
+    def closeEvent(self, event):
+        self.settings.setValue("geometry", self.saveGeometry())
+        self.settings.setValue("lastTab", self.get_current_tab_identifier())
+        super().closeEvent(event)
 
     def create_menu(self):
         menubar = self.menuBar()
@@ -200,6 +210,9 @@ class AnimeTracker(QMainWindow):
                 if t.startswith(str(identifier) + " ("):
                     self.tab_widget.setCurrentIndex(i)
                     return
+            # If the year no longer exists, default to first tab
+            if self.tab_widget.count() > 0:
+                self.tab_widget.setCurrentIndex(0)
 
     def load_tabs(self):
         self.tab_widget.clear()