chore: make Settings singleton

ui/extends/shared/settings.py

@@ -1,6 +1,8 @@
 import sys
 
-from PySide6.QtCore import QFileInfo, QSettings
+from PySide6.QtCore import QFileInfo, QSettings, Signal
+
+from .singleton import QObjectSingleton
 
 __all__ = [
     "DATABASE_URL",
@@ -29,7 +31,9 @@ ANDREAL_FOLDER = "Andreal/AndrealFolder"
 ANDREAL_EXECUTABLE = "Andreal/AndrealExecutable"
 
 
-class Settings(QSettings):
+class Settings(QSettings, metaclass=QObjectSingleton):
+    updated = Signal(str)
+
     def __init__(self, parent=None):
         super().__init__(
             QFileInfo(sys.argv[0]).dir().absoluteFilePath("arcaea_offline.ini"),
@@ -37,6 +41,10 @@ class Settings(QSettings):
             parent,
         )
 
+    def setValue(self, key: str, value) -> None:
+        super().setValue(key, value)
+        self.updated.emit(key)
+
     def _strItem(self, key: str) -> str | None:
         return self.value(key, None, str)
 

ui/extends/shared/singleton.py

@@ -0,0 +1,18 @@
+from typing import Generic, TypeVar
+
+from PySide6.QtCore import QObject
+
+T = TypeVar("T")
+
+
+class Singleton(type, Generic[T]):
+    _instance = None
+
+    def __call__(cls, *args, **kwargs) -> T:
+        if cls._instance is None:
+            cls._instance = super().__call__(*args, **kwargs)
+        return cls._instance
+
+
+class QObjectSingleton(type(QObject), Singleton):
+    pass