Fix spurious reporting of aria-hidden focus ancestors in Firefox. (nv…

…access#7357)

When presentationType is unavailable, isPresentableFocusAncestor should be False, just as it is for layout. Previously, it was True.
Unfortunately, NVDA's message dialogs are sometimes briefly treated as unavailable when they get focus. We still want them to be reported. Work around this in the app module for NVDA itself.

source/NVDAObjects/__init__.py

@@ -804,7 +804,7 @@ def _get_isPresentableFocusAncestor(self):
 		@return: C{True} if it should be presented in the focus ancestry, C{False} if not.
 		@rtype: bool
 		"""
-		if self.presentationType == self.presType_layout:
+		if self.presentationType in (self.presType_layout, self.presType_unavailable):
 			return False
 		if self.role in (controlTypes.ROLE_TREEVIEWITEM, controlTypes.ROLE_LISTITEM, controlTypes.ROLE_PROGRESSBAR, controlTypes.ROLE_EDITABLETEXT):
 			return False

source/appModules/nvda.py

@@ -1,6 +1,6 @@
 #appModules/nvda.py
 #A part of NonVisual Desktop Access (NVDA)
-#Copyright (C) 2008-2011 NV Access Inc
+#Copyright (C) 2008-2017 NV Access Limited
 #This file is covered by the GNU General Public License.
 #See the file COPYING for more details.
 
@@ -14,6 +14,20 @@
 
 nvdaMenuIaIdentity = None
 
+class NvdaDialog(IAccessible):
+	"""Fix to ensure NVDA message dialogs get reported when they pop up.
+	"""
+
+	def _get_presentationType(self):
+		presType = super(NvdaDialog, self).presentationType
+		# Sometimes, NVDA message dialogs briefly report the invisible state
+		# after they're focused.
+		# This causes them to be treated as unavailable and they are thus not reported.
+		# If this dialog is in the foreground, treat it as content.
+		if presType == self.presType_unavailable and self == api.getForegroundObject():
+			return self.presType_content
+		return presType
+
 class AppModule(appModuleHandler.AppModule):
 
 	def isNvdaMenu(self, obj):
@@ -48,3 +62,7 @@ def event_foreground         (self, obj, nextHandler):
 		if not gui.shouldConfigProfileTriggersBeSuspended():
 			config.conf.resumeProfileTriggers()
 		nextHandler()
+
+	def chooseNVDAObjectOverlayClasses(self, obj, clsList):
+		if obj.windowClassName == "#32770" and obj.role == controlTypes.ROLE_DIALOG:
+			clsList.insert(0, NvdaDialog)