UI Automation in Windows Console: limit blank lines in review and initial word movement support

source/NVDAObjects/UIA/winConsoleUIA.py

@@ -5,6 +5,8 @@
 # Copyright (C) 2019 Bill Dengler
 
 import config
+import ctypes
+import NVDAHelper
 import speech
 import time
 import textInfos
@@ -21,16 +23,164 @@ class consoleUIATextInfo(UIATextInfo):
 
 	def __init__(self, obj, position, _rangeObj=None):
 		super(consoleUIATextInfo, self).__init__(obj, position, _rangeObj)
-		if position == textInfos.POSITION_CARET:
-			if isAtLeastWin10(1903):
-				# The UIA implementation in 1903 causes the caret to be
-				# off-by-one, so move it one position to the right
-				# to compensate.
+		if position == textInfos.POSITION_CARET and isAtLeastWin10(1903):
+			# 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(
+				UIAHandler.TextPatternRangeEndpoint_Start,
+				UIAHandler.NVDAUnitsToUIAUnits[textInfos.UNIT_CHARACTER],
+				1
+			)
+
+	def move(self, unit, direction, endPoint=None):
+		oldRange = None
+		if self.basePosition != textInfos.POSITION_CARET:
+			# Insure we haven't gone beyond the visible text.
+			# UIA adds thousands of blank lines to the end of the console.
+			visiRanges = self.obj.UIATextPattern.GetVisibleRanges()
+			visiLength = visiRanges.length
+			if visiLength > 0:
+				firstVisiRange = visiRanges.GetElement(0)
+				lastVisiRange = visiRanges.GetElement(visiLength - 1)
+				oldRange = self._rangeObj.clone()
+		if unit == textInfos.UNIT_WORD and direction != 0:
+			# UIA doesn't implement word movement, so we need to do it manually.
+			# Relative to the current line, calculate our offset
+			# and the current word's offsets.
+			lineInfo = self.copy()
+			lineInfo.expand(textInfos.UNIT_LINE)
+			offset = self._getCurrentOffsetInThisLine(lineInfo)
+			start, end = self._getWordOffsetsInThisLine(offset, lineInfo)
+			if direction > 0:
+				# Moving in a forward direction, we can just jump to the
+				# end offset of the current word and we're done.
+				res = self.move(
+					textInfos.UNIT_CHARACTER,
+					end - offset,
+					endPoint=endPoint
+				)
+			else:
+				# Moving backwards
+				wordStartDistance = (offset - start) * -1
+				if wordStartDistance < 0:
+					# We are after the beginning of a word.
+					# So first move back to the start of the word.
+					self.move(
+						textInfos.UNIT_CHARACTER,
+						wordStartDistance,
+						endPoint=endPoint
+					)
+					offset += wordStartDistance
+				# Try to move one character back before the start of the word.
+				res = self.move(textInfos.UNIT_CHARACTER, -1, endPoint=endPoint)
+				if res == 0:
+					return 0
+				offset -= 1
+				# We are now positioned  within the previous word.
+				if offset < 0:
+					# We've moved on to the previous line.
+					# Recalculate the current offset based on the new line we are now on.
+					lineInfo = self.copy()
+					lineInfo.expand(textInfos.UNIT_LINE)
+					offset = self._getCurrentOffsetInThisLine(lineInfo)
+				# Finally using the new offset,
+
+				# Calculate the current word offsets and move to the start of
+				# this word if we are not already there.
+				start, end = self._getWordOffsetsInThisLine(offset, lineInfo)
+				wordStartDistance = (offset - start) * -1
+				if wordStartDistance < 0:
+					self.move(
+						textInfos.UNIT_CHARACTER,
+						wordStartDistance,
+						endPoint=endPoint
+					)
+		else:  # moving by a unit other than word
+			res = super(consoleUIATextInfo, self).move(unit, direction, endPoint)
+		if oldRange and (
+			self._rangeObj.CompareEndPoints(
+				UIAHandler.TextPatternRangeEndpoint_Start,
+				firstVisiRange,
+				UIAHandler.TextPatternRangeEndpoint_Start
+			) < 0
+			or self._rangeObj.CompareEndPoints(
+				UIAHandler.TextPatternRangeEndpoint_Start,
+				lastVisiRange,
+				UIAHandler.TextPatternRangeEndpoint_End
+			) >= 0
+		):
+			self._rangeObj = oldRange
+			return 0
+		return res
+
+	def expand(self, unit):
+		if unit == textInfos.UNIT_WORD:
+			# UIA doesn't implement word movement, so we need to do it manually.
+			lineInfo = self.copy()
+			lineInfo.expand(textInfos.UNIT_LINE)
+			offset = self._getCurrentOffsetInThisLine(lineInfo)
+			start, end = self._getWordOffsetsInThisLine(offset, lineInfo)
+			wordEndPoints = (
+				(offset - start) * -1,
+				end - offset - 1
+			)
+			if wordEndPoints[0]:
 				self._rangeObj.MoveEndpointByUnit(
 					UIAHandler.TextPatternRangeEndpoint_Start,
 					UIAHandler.NVDAUnitsToUIAUnits[textInfos.UNIT_CHARACTER],
-					1
+					wordEndPoints[0]
 				)
+			if wordEndPoints[1]:
+				self._rangeObj.MoveEndpointByUnit(
+					UIAHandler.TextPatternRangeEndpoint_End,
+					UIAHandler.NVDAUnitsToUIAUnits[textInfos.UNIT_CHARACTER],
+					wordEndPoints[1]
+				)
+		else:
+			return super(consoleUIATextInfo, self).expand(unit)
+
+	def _getCurrentOffsetInThisLine(self, lineInfo):
+		charInfo = self.copy()
+		res = 0
+		chars = None
+		while charInfo.compareEndPoints(
+			lineInfo,
+			"startToEnd"
+		) <= 0:
+			charInfo.expand(textInfos.UNIT_CHARACTER)
+			chars = charInfo.move(textInfos.UNIT_CHARACTER, -1) * -1
+			if chars != 0 and charInfo.compareEndPoints(
+				lineInfo,
+				"startToStart"
+			) >= 0:
+				res += chars
+			else:
+				break
+		return res
+
+	def _getWordOffsetsInThisLine(self, offset, lineInfo):
+		lineText = lineInfo.text or u" "
+		# Convert NULL and non-breaking space to space to make sure
+		# that words will break on them
+		lineText = lineText.translate({0: u' ', 0xa0: u' '})
+		start = ctypes.c_int()
+		end = ctypes.c_int()
+		# Uniscribe does some strange things when you give it a string  with
+		# not more than two alphanumeric chars in a row.
+		# Inject two alphanumeric characters at the end to fix this.
+		lineText += "xx"
+		NVDAHelper.localLib.calculateWordOffsets(
+			lineText,
+			len(lineText),
+			offset,
+			ctypes.byref(start),
+			ctypes.byref(end)
+		)
+		return (
+			start.value,
+			min(end.value, max(1, len(lineText) - 2))
+		)
 
 
 class winConsoleUIA(Terminal):
@@ -90,7 +240,6 @@ def script_clear_isTyping(self, gesture):
 
 	def _getTextLines(self):
 		# Filter out extraneous empty lines from UIA
-		# Todo: do this (also) somewhere else so they aren't in document review either
 		ptr = self.UIATextPattern.GetVisibleRanges()
 		res = [ptr.GetElement(i).GetText(-1) for i in range(ptr.length)]
 		return res