NVDA objects/API handlers/Python 3: add explanatory comments. Re nvac…

…cess#7105.

Comment from Reef Turner (NV Access): add explanatory comment, prefixing the comment with '# Py3 review required'. Because some changes are based on another issue (nvaccess#9067, for example), prefix the review comment with issue number references as appropriate.

source/IAccessibleHandler.py

@@ -832,6 +832,8 @@ def initialize():
 		accPropServices=comtypes.client.CreateObject(CAccPropServices)
 	except (WindowsError,COMError) as e:
 		log.debugWarning("AccPropServices is not available: %s"%e)
+	# #9067 (Py3 review required): originally, this calls dict.keys, which in Python 2 returns a list and Python 3 assumes iterators.
+	# Therefore wrap this around a list call.
 	for eventType in list(winEventIDsToNVDAEventNames.keys()):
 		hookID=winUser.setWinEventHook(eventType,eventType,0,cWinEventCallback,0,0,0)
 		if hookID:

source/JABHandler.py

@@ -5,6 +5,7 @@
 #This file is covered by the GNU General Public License.
 #See the file COPYING for more details.
 
+# Py3 review required: Python 2 "Queue" vs Python 3 "queue".
 import queue
 from ctypes import *
 from ctypes.wintypes import *

source/NVDAHelper.py

@@ -6,6 +6,7 @@
 
 import os
 import sys
+# Py3 review required: Python 2 "_winreg" vs Python 3 "winreg".
 import winreg
 import msvcrt
 import versionInfo

source/NVDAObjects/IAccessible/__init__.py

@@ -848,11 +848,14 @@ def _get_states(self):
 		except COMError:
 			log.debugWarning("could not get IAccessible states",exc_info=True)
 		else:
+			# Py3 review required: Python 2 "dict.has_key" vs Python 3 "key in dict".
+			# Also, try splitting this line for improved readability.
 			states.update(IAccessibleHandler.IAccessibleStatesToNVDAStates[x] for x in (y for y in (1<<z for z in range(32)) if y&IAccessibleStates) if x in IAccessibleHandler.IAccessibleStatesToNVDAStates)
 		if not hasattr(self.IAccessibleObject,'states'):
 			# Not an IA2 object.
 			return states
 		IAccessible2States=self.IA2States
+		# Py3 review required: Python 2 "dict.has_key' vs Python 3 "key in dict".
 		states=states|set(IAccessibleHandler.IAccessible2StatesToNVDAStates[x] for x in (y for y in (1<<z for z in range(32)) if y&IAccessible2States) if x in IAccessibleHandler.IAccessible2StatesToNVDAStates)
 		# Readonly should override editable
 		if controlTypes.STATE_READONLY in states:
@@ -1368,6 +1371,8 @@ def _get_positionInfo(self):
 					del info['indexInGroup']
 					del info['similarItemsInGroup']
 				# 0 means not applicable, so remove it.
+				# #9067 (Py3 review required): originally this called dict.items, which returns iterators in Python 3.
+				# Therefore wrap this inside a list call.
 				for key, val in list(info.items()):
 					if not val:
 						del info[key]

source/NVDAObjects/JAB/__init__.py

@@ -284,6 +284,7 @@ def _get_states(self):
 		stateString=self.JABStates
 		stateStrings=stateString.split(',')
 		for state in stateStrings:
+			# Py3 review required: Python 2 "dict.has_key" vs Python 3 "key in dict".
 			if state in JABStatesToNVDAStates:
 				stateSet.add(JABStatesToNVDAStates[state])
 		if "visible" not in stateStrings:

source/NVDAObjects/window/excelCellBorder.py

@@ -107,6 +107,8 @@
 
 def getCellBorderStyleDescription(bordersObj,reportBorderColor=False):
 	d=OrderedDict()
+	# #9067 (Py3 review required): originally called dict.keys.
+	# Therefore wrap this inside list call.
 	for pos in list(bordersIndexLabels.keys()):
 		border=bordersObj[pos]
 		if border.lineStyle != xlLineStyleNone:
@@ -150,6 +152,8 @@ def getCellBorderStyleDescription(bordersObj,reportBorderColor=False):
 		s.append(_("{desc} up-right and down-right diagonal lines").format(desc=d.get(xlDiagonalUp)))
 		del d[xlDiagonalUp]
 		del d[xlDiagonalDown]
+	# #9067 (Py3 review required): Originally caled dict.items.
+	# Therefore wrap this inside a list call.
 	for pos,desc in list(d.items()):
 		# Translators: border styles in Microsoft Excel.
 		s.append(_("{desc} {position}").format(

source/_UIAHandler.py

@@ -237,7 +237,10 @@ def MTAThreadFunc(self):
 			self.reservedNotSupportedValue=self.clientObject.ReservedNotSupportedValue
 			self.ReservedMixedAttributeValue=self.clientObject.ReservedMixedAttributeValue
 			self.clientObject.AddFocusChangedEventHandler(self.baseCacheRequest,self)
+			# #9067 (Py3 review required): originally called dict.keys.
+			# Therefore wrap this inside a list call.
 			self.clientObject.AddPropertyChangedEventHandler(self.rootElement,TreeScope_Subtree,self.baseCacheRequest,self,list(UIAPropertyIdsToNVDAEventNames.keys()))
+			# #9067 (Py3 review required): because dict.iterkeys returns an iterator, and since that will be the behavior in Python 3 anyway, just use "key in dict",
 			for x in UIAEventIdsToNVDAEventNames:  
 				self.clientObject.addAutomationEventHandler(x,self.rootElement,TreeScope_Subtree,self.baseCacheRequest,self)
 			# #7984: add support for notification event (IUIAutomation5, part of Windows 10 build 16299 and later).