add type annotations other than Dispatch func (#444)

Author: junkmd

comtypes/client/dynamic.py

@@ -1,9 +1,12 @@
 import ctypes
+from typing import Any, Dict, Optional, Set, Type, TypeVar
 
 from comtypes import automation
 from comtypes.client import lazybind
-from comtypes import COMError, hresult as hres, _is_object
+from comtypes import COMError, GUID, IUnknown, hresult as hres, _is_object
 
+
+_T_IUnknown = TypeVar("_T_IUnknown", bound=IUnknown)
 # These errors generally mean the property or method exists,
 # but can't be used in this context - eg, property instead of a method, etc.
 # Used to determine if we have a real error or not.
@@ -17,8 +20,9 @@
 
 
 def Dispatch(obj):
-    # Wrap an object in a Dispatch instance, exposing methods and properties
-    # via fully dynamic dispatch
+    """Wrap an object in a Dispatch instance, exposing methods and properties
+    via fully dynamic dispatch.
+    """
     if isinstance(obj, _Dispatch):
         return obj
     if isinstance(obj, ctypes.POINTER(automation.IDispatch)):
@@ -33,19 +37,19 @@ def Dispatch(obj):
 class MethodCaller:
     # Wrong name: does not only call methods but also handle
     # property accesses.
-    def __init__(self, _id, _obj):
+    def __init__(self, _id: int, _obj: "_Dispatch") -> None:
         self._id = _id
         self._obj = _obj
 
-    def __call__(self, *args):
+    def __call__(self, *args: Any) -> Any:
         return self._obj._comobj.Invoke(self._id, *args)
 
-    def __getitem__(self, *args):
+    def __getitem__(self, *args: Any) -> Any:
         return self._obj._comobj.Invoke(
             self._id, *args, _invkind=automation.DISPATCH_PROPERTYGET
         )
 
-    def __setitem__(self, *args):
+    def __setitem__(self, *args: Any) -> None:
         if _is_object(args[-1]):
             self._obj._comobj.Invoke(
                 self._id, *args, _invkind=automation.DISPATCH_PROPERTYPUTREF
@@ -57,22 +61,26 @@ def __setitem__(self, *args):
 
 
 class _Dispatch(object):
-    # Expose methods and properties via fully dynamic dispatch
-    def __init__(self, comobj):
+    """Expose methods and properties via fully dynamic dispatch."""
+
+    _comobj: automation.IDispatch
+    _ids: Dict[str, int]
+    _methods: Set[str]
+
+    def __init__(self, comobj: "ctypes._Pointer[automation.IDispatch]"):
         self.__dict__["_comobj"] = comobj
-        self.__dict__[
-            "_ids"
-        ] = {}  # Tiny optimization: trying not to use GetIDsOfNames more than once
+        # Tiny optimization: trying not to use GetIDsOfNames more than once
+        self.__dict__["_ids"] = {}
         self.__dict__["_methods"] = set()
 
-    def __enum(self):
-        e = self._comobj.Invoke(-4)  # DISPID_NEWENUM
+    def __enum(self) -> automation.IEnumVARIANT:
+        e: IUnknown = self._comobj.Invoke(-4)  # DISPID_NEWENUM
         return e.QueryInterface(automation.IEnumVARIANT)
 
-    def __hash__(self):
+    def __hash__(self) -> int:
         return hash(self._comobj)
 
-    def __getitem__(self, index):
+    def __getitem__(self, index: Any) -> Any:
         enum = self.__enum()
         if index > 0:
             if 0 != enum.Skip(index):
@@ -82,11 +90,13 @@ def __getitem__(self, index):
             raise IndexError("index out of range")
         return item
 
-    def QueryInterface(self, interface, iid=None):
+    def QueryInterface(
+        self, interface: Type[_T_IUnknown], iid: Optional[GUID] = None
+    ) -> _T_IUnknown:
         """QueryInterface is forwarded to the real com object."""
         return self._comobj.QueryInterface(interface, iid)
 
-    def _FlagAsMethod(self, *names):
+    def _FlagAsMethod(self, *names: str) -> None:
         """Flag these attribute names as being methods.
         Some objects do not correctly differentiate methods and
         properties, leading to problems when calling these methods.
@@ -100,7 +110,7 @@ def _FlagAsMethod(self, *names):
         """
         self._methods.update(names)
 
-    def __getattr__(self, name):
+    def __getattr__(self, name: str) -> Any:
         if name.startswith("__") and name.endswith("__"):
             raise AttributeError(name)
         # tc = self._comobj.GetTypeInfo(0).QueryInterface(comtypes.typeinfo.ITypeComp)
@@ -119,20 +129,16 @@ def __getattr__(self, name):
         try:
             result = self._comobj.Invoke(dispid, _invkind=flags)
         except COMError as err:
-            (hresult, text, details) = err.args
+            (hresult, _, _) = err.args
             if hresult in ERRORS_BAD_CONTEXT:
                 result = MethodCaller(dispid, self)
                 self.__dict__[name] = result
             else:
-                # The line break is important for 2to3 to work correctly
-                raise
-        except:
-            # The line break is important for 2to3 to work correctly
-            raise
+                raise err
 
         return result
 
-    def __setattr__(self, name, value):
+    def __setattr__(self, name: str, value: Any) -> None:
         dispid = self._ids.get(name)
         if not dispid:
             dispid = self._comobj.GetIDsOfNames(name)[0]
@@ -142,7 +148,7 @@ def __setattr__(self, name, value):
         flags = 8 if _is_object(value) else 4
         return self._comobj.Invoke(dispid, value, _invkind=flags)
 
-    def __iter__(self):
+    def __iter__(self) -> "_Collection":
         return _Collection(self.__enum())
 
     # def __setitem__(self, index, value):
@@ -156,10 +162,10 @@ def __iter__(self):
 
 
 class _Collection(object):
-    def __init__(self, enum):
+    def __init__(self, enum: automation.IEnumVARIANT):
         self.enum = enum
 
-    def __next__(self):
+    def __next__(self) -> Any:
         item, fetched = self.enum.Next(1)
         if fetched:
             return item