UI Automation in Windows Console: work around Microsoft bugs on Windows 10 version 1903 and improve caret movement

source/NVDAObjects/UIA/winConsoleUIA.py

@@ -21,19 +21,25 @@
 
 class consoleUIATextInfo(UIATextInfo):
 	#: At least on Windows 10 1903, expanding then collapsing the text info
-	#: causes review to get stuck, so disable it.
+	#: caused review to get stuck, so disable it.
+	#: There may be no need to disable this anymore, but doing so doesn't seem
+	#: to do much good either.
 	_expandCollapseBeforeReview = False
 
-	def __init__(self, obj, position, _rangeObj=None):
-		super(consoleUIATextInfo, self).__init__(obj, position, _rangeObj)
-		if position == textInfos.POSITION_CARET and isWin10(1903, atLeast=False):
-			# The UIA implementation in 1903 causes the caret to be
-			# off-by-one, so move it one position to the right
-			# to compensate.
-			self._rangeObj.MoveEndpointByUnit(
+	def collapse(self,end=False):
+		"""Works around a UIA bug on Windows 10 1903 and later."""
+		if not isWin10(1903):
+			return super(consoleUIATextInfo, self).collapse(end=end)
+		# When collapsing, consoles seem to incorrectly push the start of the
+		# textRange back one character.
+		# Correct this by bringing the start back up to where the end is.
+		oldInfo=self.copy()
+		super(consoleUIATextInfo,self).collapse()
+		if not end:
+			self._rangeObj.MoveEndpointByRange(
 				UIAHandler.TextPatternRangeEndpoint_Start,
-				UIAHandler.NVDAUnitsToUIAUnits[textInfos.UNIT_CHARACTER],
-				1
+				oldInfo._rangeObj,
+				UIAHandler.TextPatternRangeEndpoint_Start
 			)
 
 	def move(self, unit, direction, endPoint=None):
@@ -139,6 +145,17 @@ def expand(self, unit):
 		else:
 			return super(consoleUIATextInfo, self).expand(unit)
 
+	def _get_isCollapsed(self):
+		"""Works around a UIA bug on Windows 10 1903 and later."""
+		if not isWin10(1903):
+			return super(consoleUIATextInfo, self)._get_isCollapsed()
+		# Even when a console textRange's start and end have been moved to the
+		# same position, the console incorrectly reports the end as being
+		# past the start.
+		# Therefore to decide if the textRange is collapsed,
+		# Check if it has no text.
+		return not bool(self._rangeObj.getText(1))
+
 	def _getCurrentOffsetInThisLine(self, lineInfo):
 		"""
 		Given a caret textInfo expanded to line, returns the index into the
@@ -187,6 +204,9 @@ def _getWordOffsetsInThisLine(self, offset, lineInfo):
 			min(end.value, max(1, len(lineText) - 2))
 		)
 
+	def __ne__(self,other):
+		return not self==other
+
 
 class consoleUIAWindow(Window):
 	def _get_focusRedirect(self):
@@ -215,6 +235,8 @@ class WinConsoleUIA(Terminal):
 	#: Whether the console got new text lines in its last update.
 	#: Used to determine if typed character/word buffers should be flushed.
 	_hasNewLines = False
+	#: the caret in consoles can take a while to move on Windows 10 1903 and later.
+	_caretMovementTimeoutMultiplier = 2
 
 	def _reportNewText(self, line):
 		# Additional typed character filtering beyond that in LiveText

source/_UIAHandler.py

@@ -151,7 +151,10 @@
 }
 
 if winVersion.isWin10():
-	UIAEventIdsToNVDAEventNames[UIA_Text_TextChangedEventId] = "textChange"
+	UIAEventIdsToNVDAEventNames.update({
+		UIA_Text_TextChangedEventId: "textChange",
+		UIA_Text_TextSelectionChangedEventId:"caret"
+	})
 
 ignoreWinEventsMap = {
 	UIA_AutomationPropertyChangedEventId: list(UIAPropertyIdsToNVDAEventNames.keys()),

source/editableText.py

@@ -48,6 +48,8 @@ class EditableText(TextContainerObject,ScriptableObject):
 
 	_hasCaretMoved_minWordTimeoutMs=30 #: The minimum amount of time that should elapse before checking if the word under the caret has changed
 
+	_caretMovementTimeoutMultiplier = 1
+
 	def _hasCaretMoved(self, bookmark, retryInterval=0.01, timeout=None, origWord=None):
 		"""
 		Waits for the caret to move, for a timeout to elapse, or for a new focus event or script to be queued.
@@ -69,6 +71,7 @@ def _hasCaretMoved(self, bookmark, retryInterval=0.01, timeout=None, origWord=No
 		else:
 			# This function's arguments are in seconds, but we want ms.
 			timeoutMs = timeout * 1000
+		timeoutMs *= self._caretMovementTimeoutMultiplier
 		# time.sleep accepts seconds, so retryInterval is in seconds.
 		# Convert to integer ms to avoid floating point precision errors when adding to elapsed.
 		retryMs = int(retryInterval * 1000)
@@ -81,6 +84,10 @@ def _hasCaretMoved(self, bookmark, retryInterval=0.01, timeout=None, origWord=No
 			if eventHandler.isPendingEvents("gainFocus"):
 				log.debug("Focus event. Elapsed: %d ms" % elapsed)
 				return (True,None)
+			# Some controls implement a caret event
+			if eventHandler.isPendingEvents("caret"):
+				newInfo = self.makeTextInfo(textInfos.POSITION_CARET)
+				return (True, newInfo)
 			# If the focus changes after this point, fetching the caret may fail,
 			# but we still want to stay in this loop.
 			try:

source/textInfos/__init__.py

@@ -216,8 +216,6 @@ def __eq__(self,other):
 		if isinstance(other,Bookmark) and self.infoClass==other.infoClass and self.data==other.data:
 			return True
 
-	def __ne__(self,other):
-		return not self==other
 
 #Unit constants
 UNIT_CHARACTER="character"