Work around VS Code specific performance issues (PR #11657)

source/appModules/code - insiders.py

@@ -0,0 +1,11 @@
+# A part of NonVisual Desktop Access (NVDA)
+# Copyright (C) 2020 NV Access Limited, Leonard de Ruijter
+# This file is covered by the GNU General Public License.
+# See the file COPYING for more details.
+
+""" App module for Visual Studio Code Insiders.
+This app module simply inherrits from the app module for the stable version of Code.
+"""
+
+# Ignoring Flake8 imported but unused error since appModuleHandler yet uses the import.
+from .code import AppModule  # noqa: F401

source/appModules/code.py

@@ -0,0 +1,26 @@
+# A part of NonVisual Desktop Access (NVDA)
+# Copyright (C) 2020 NV Access Limited, Leonard de Ruijter
+# This file is covered by the GNU General Public License.
+# See the file COPYING for more details.
+
+""" App module for Visual Studio Code.
+"""
+
+import appModuleHandler
+from NVDAObjects.IAccessible.chromium import Document
+from NVDAObjects import NVDAObject
+
+
+class VSCodeDocument(Document):
+	"""The only content in the root document node of Visual Studio code is the application object.
+	Creating a tree interceptor on this object causes a major slow down of Code.
+	Therefore, forcefully block tree interceptor creation.
+	"""
+	_get_treeInterceptorClass = NVDAObject._get_treeInterceptorClass
+
+
+class AppModule(appModuleHandler.AppModule):
+
+	def chooseNVDAObjectOverlayClasses(self, obj, clsList):
+		if Document in clsList and obj.IA2Attributes.get("tag") == "#document":
+			clsList.insert(0, VSCodeDocument)

user_docs/en/changes.t2t

@@ -56,6 +56,7 @@ The existence of marked (highlighted) content can be reported in browsers, and t
 - The expanded / collapsed state of directories in the navigation treeview on drive.google.com is now always reported by NVDA. (#11520)
 - NVDA will auto detect the NLS eReader Humanware braille display via Bluetooth as its Bluetooth name is now "NLS eReader Humanware". (#11561)
 - Certain SAPI5 voices (such as Ivona) no longer skip speech. (#10901)
+- Major performance improvements in Visual Studio Code. (#11533)
 
 
 == Changes For Developers ==