remove old hack

src/textual/_context.py

@@ -1,8 +1,7 @@
 from __future__ import annotations
 
-import weakref
-from contextvars import ContextVar, Token
-from typing import TYPE_CHECKING, Callable, Generic, TypeVar, overload
+from contextvars import ContextVar
+from typing import TYPE_CHECKING, Any, Callable, TypeVar
 
 if TYPE_CHECKING:
     from .app import App
@@ -19,54 +18,8 @@ class NoActiveAppError(RuntimeError):
 DefaultType = TypeVar("DefaultType")
 
 
-class ContextDefault:
-    pass
-
-
-_context_default = ContextDefault()
-
-
-class TextualContextVar(Generic[ContextVarType]):
-    """Like ContextVar but doesn't hold on to references."""
-
-    def __init__(self, name: str) -> None:
-        self._context_var: ContextVar[weakref.ReferenceType[ContextVarType]] = (
-            ContextVar(name)
-        )
-
-    @overload
-    def get(self) -> ContextVarType: ...
-
-    @overload
-    def get(self, default: DefaultType) -> ContextVarType | DefaultType: ...
-
-    def get(
-        self, default: DefaultType | ContextDefault = _context_default
-    ) -> ContextVarType | DefaultType:
-        try:
-            value_ref = self._context_var.get()
-        except LookupError:
-            if isinstance(default, ContextDefault):
-                raise
-            return default
-        value = value_ref()
-        if value is None:
-            if isinstance(default, ContextDefault):
-                raise LookupError(value)
-            return default
-        return value
-
-    def set(self, value: ContextVarType) -> object:
-        return self._context_var.set(weakref.ref(value))
-
-    def reset(self, token: Token[weakref.ReferenceType[ContextVarType]]) -> None:
-        self._context_var.reset(token)
-
-
-active_app: TextualContextVar["App[object]"] = TextualContextVar("active_app")
-active_message_pump: TextualContextVar["MessagePump"] = TextualContextVar(
-    "active_message_pump"
-)
+active_app: ContextVar["App[Any]"] = ContextVar("active_app")
+active_message_pump: ContextVar["MessagePump"] = ContextVar("active_message_pump")
 
 prevent_message_types_stack: ContextVar[list[set[type[Message]]]] = ContextVar(
     "prevent_message_types_stack"
@@ -75,7 +28,5 @@ def reset(self, token: Token[weakref.ReferenceType[ContextVarType]]) -> None:
     "visible_screen_stack"
 )
 """A stack of visible screens (with background alpha < 1), used in the screen render process."""
-message_hook: TextualContextVar[Callable[[Message], None]] = TextualContextVar(
-    "message_hook"
-)
+message_hook: ContextVar[Callable[[Message], None]] = ContextVar("message_hook")
 """A callable that accepts a message. Used by App.run_test."""