generic typing of field definitions and value getter function for single widgets

src/wce_crm/form_defs.py

@@ -4,12 +4,17 @@ import dataclasses as dc
 import enum
 import uuid
 from collections.abc import Sequence
-from typing import Any, Final
+from typing import TYPE_CHECKING, Any, Final, Generic, TypeVar
 
 import babel
 
 from wce_crm.custom_widget_registry import CUSTOM_WIDGET_NAMES
 
+if TYPE_CHECKING:
+    from PySide6.QtWidgets import QWidget
+
+T = TypeVar("T", bound="QWidget")
+
 
 class FormFieldType(enum.StrEnum):
     GROUP = enum.auto()
@@ -31,7 +36,7 @@ class FormFieldType(enum.StrEnum):
 
 
 @dc.dataclass(slots=True)
-class FormField:
+class FormField(Generic[T]):
     label: str
     type: FormFieldType
     children: Sequence[FormField] = dc.field(default_factory=list)