Touch interaction: allow users to disable touch support completely

source/config/configSpec.py

@@ -161,6 +161,7 @@
 	autoFocusFocusableElements = boolean(default=True)
 
 [touch]
+	enabled = boolean(default=true)
 	touchTyping = boolean(default=False)
 
 #Settings for document reading (such as MS Word and wordpad)

source/gui/settingsDialogs.py

@@ -2217,14 +2217,21 @@ class TouchInteractionPanel(SettingsPanel):
 	title = _("Touch Interaction")
 
 	def makeSettings(self, settingsSizer):
+		sHelper = guiHelper.BoxSizerHelper(self, sizer=settingsSizer)
+		# Translators: This is the label for a checkbox in the
+		# touch interaction settings panel.
+		touchSupportEnableLabel = _("Enable touch interaction support")
+		self.enableTouchSupportCheckBox = sHelper.addItem(wx.CheckBox(self, label=touchSupportEnableLabel))
+		self.enableTouchSupportCheckBox.SetValue(config.conf["touch"]["enabled"])
 		# Translators: This is the label for a checkbox in the
 		# touch interaction settings panel.
-		self.touchTypingCheckBox=wx.CheckBox(self,label=_("&Touch typing mode"))
+		self.touchTypingCheckBox = sHelper.addItem(wx.CheckBox(self, label=_("&Touch typing mode")))
 		self.touchTypingCheckBox.SetValue(config.conf["touch"]["touchTyping"])
-		settingsSizer.Add(self.touchTypingCheckBox,border=10,flag=wx.BOTTOM)
 
 	def onSave(self):
-		config.conf["touch"]["touchTyping"]=self.touchTypingCheckBox.IsChecked()
+		config.conf["touch"]["enabled"] = self.enableTouchSupportCheckBox.IsChecked()
+		config.conf["touch"]["touchTyping"] = self.touchTypingCheckBox.IsChecked()
+		touchHandler.setTouchSupport(config.conf["touch"]["enabled"])
 
 class UwpOcrPanel(SettingsPanel):
 	# Translators: The title of the Windows 10 OCR panel.

source/touchHandler.py

@@ -1,8 +1,7 @@
-#touchHandler.py
-#A part of NonVisual Desktop Access (NVDA)
-#This file is covered by the GNU General Public License.
-#See the file COPYING for more details.
-#Copyright (C) 2012-2018 NV Access Limited, Joseph Lee, Babbage B.V.
+# A part of NonVisual Desktop Access (NVDA)
+# This file is covered by the GNU General Public License.
+# See the file COPYING for more details.
+# Copyright (C) 2012-2020 NV Access Limited, Joseph Lee, Babbage B.V.
 
 """handles touchscreen interaction (Windows 8 and later).
 Used to provide input gestures for touchscreens, touch modes and other support facilities.
@@ -294,30 +293,57 @@ def notifyInteraction(self, obj):
 
 handler=None
 
-def touchSupported():
+
+def touchSupported(debugLog: bool = False):
 	"""Returns if the system and current NVDA session supports touchscreen interaction.
+	@param debugLog: Whether to log additional details about touch support to the NVDA log.
 	"""
 	if not config.isInstalledCopy() and not config.isAppX:
-		log.debugWarning("Touch only supported on installed copies")
+		if debugLog:
+			log.debugWarning("Touch only supported on installed copies")
 		return False
-	if (winVersion.winVersion.major*10+winVersion.winVersion.minor)<62:
-		log.debugWarning("Touch only supported on Windows 8 and higher")
+	if winVersion.winVersion.platform_version < (6, 2, 9200):
+		if debugLog:
+			log.debugWarning("Touch only supported on Windows 8 and higher")
 		return False
 	maxTouches=windll.user32.GetSystemMetrics(SM_MAXIMUMTOUCHES)
 	if maxTouches<=0:
-		log.debugWarning("No touch devices found")
+		if debugLog:
+			log.debugWarning("No touch devices found")
 		return False
 	return True
 
-def initialize():
+
+def setTouchSupport(enable: bool):
 	global handler
 	if not touchSupported():
 		raise NotImplementedError
-	handler=TouchHandler()
-	log.debug("Touch support initialized. maximum touch inputs: %d"%windll.user32.GetSystemMetrics(SM_MAXIMUMTOUCHES))
+	if not handler and enable:
+		handler = TouchHandler()
+		log.debug("Touch support enabled.")
+	elif handler and not enable:
+		handler.terminate()
+		handler = None
+		log.debug("Touch support disabled.")
+
+
+def handlePostConfigProfileSwitch():
+	setTouchSupport(config.conf["touch"]["enabled"])
+
+
+def initialize():
+	global handler
+	if not touchSupported(debugLog=True):
+		raise NotImplementedError
+	log.debug(
+		"Touchscreen detected, maximum touch inputs: %d" % winUser.user32.GetSystemMetrics(SM_MAXIMUMTOUCHES)
+	)
+	config.post_configProfileSwitch.register(handlePostConfigProfileSwitch)
+	setTouchSupport(config.conf["touch"]["enabled"])
 
 def terminate():
 	global handler
+	config.post_configProfileSwitch.unregister(handlePostConfigProfileSwitch)
 	if handler:
 		handler.terminate()
 		handler=None

user_docs/en/userGuide.t2t

@@ -203,8 +203,9 @@ If your laptop cannot do this or does not allow you to turn Num Lock off, you ma
 
 ++ NVDA Touch Gestures ++[NVDATouchGestures]
 If you are running NVDA on a device with a touchscreen and running Windows 8 or higher, you can also control NVDA directly via touch commands.
-While NVDA is running, all touch input will go directly to NVDA. 
+While NVDA is running, unless touch interaction support is disabled, all touch input will go directly to NVDA. 
 Therefore, actions that can be performed normally without NVDA will not work.
+You can change this by enabling or disabling [touch interaction support # TouchSupportEnable] from touch interaction category of the NVDA settings.
 
 +++ Exploring the Screen +++[ExploringTheScreen]
 The most basic action you can perform with the touch screen is to announce the control or text at any point on the screen.
@@ -1513,6 +1514,11 @@ If you check this option and you have the "Enable mouse tracking" option enabled
 This settings category, only available on computers running Windows 8 and later with touch capabilities, allows you to configure how NVDA interacts with touchscreens.
 This category contains the following options:
 
+==== Enable touch interaction support ====[TouchSupportEnable]
+This checkbox enables NVDA's touch interaction support.
+If enabled, you can use your fingers to navigate and interact with items on screen using a touchscreen device.
+If disabled, touchscreen support will be disabled as though NVDA is not running.
+
 ==== Touch typing mode ====[TouchTypingMode]
 This checkbox allows you to specify the method you wish to use when entering text using the touch keyboard.
 If this checkbox is checked, when you locate a key on the touch keyboard, you can lift your finger and the selected key will be pressed.