Add support for aria placeholder (PR #7055)

Fixes #7004

Aria-placeholder now supported in Chrome, Firefox, Edge and IE. Placeholder is reported unless the field has some content.

nvdaHelper/vbufBackends/mshtml/mshtml.cpp

@@ -490,6 +490,7 @@ inline void getAttributesFromHTMLDOMNode(IHTMLDOMNode* pHTMLDOMNode,wstring& nod
 	macro_addHTMLAttributeToMap(L"aria-busy",false,pHTMLAttributeCollection2,attribsMap,tempVar,tempAttribNode);
 	macro_addHTMLAttributeToMap(L"aria-atomic",false,pHTMLAttributeCollection2,attribsMap,tempVar,tempAttribNode);
 	macro_addHTMLAttributeToMap(L"aria-current",false,pHTMLAttributeCollection2,attribsMap,tempVar,tempAttribNode);
+	macro_addHTMLAttributeToMap(L"aria-placeholder",false,pHTMLAttributeCollection2,attribsMap,tempVar,tempAttribNode);
 	pHTMLAttributeCollection2->Release();
 }
 

source/NVDAObjects/IAccessible/MSHTML.py

@@ -523,6 +523,9 @@ def _get_isCurrent(self):
 	def _get_HTMLAttributes(self):
 		return HTMLAttribCache(self.HTMLNode)
 
+	def _get_placeholder(self):
+		return self.HTMLAttributes["aria-placeholder"]
+
 	def __init__(self,HTMLNode=None,IAccessibleObject=None,IAccessibleChildID=None,**kwargs):
 		self.HTMLNodeHasAncestorIAccessible=False
 		if not IAccessibleObject:

source/NVDAObjects/IAccessible/ia2Web.py

@@ -33,6 +33,10 @@ def _get_isCurrent(self):
 		current = self.IA2Attributes.get("current", False)
 		return current
 
+	def _get_placeholder(self):
+		placeholder = self.IA2Attributes.get('placeholder', None)
+		return placeholder
+
 class Document(Ia2Web):
 	value = None
 

source/NVDAObjects/UIA/edge.py

@@ -21,6 +21,43 @@
 from UIAUtils import *
 from . import UIA, UIATextInfo
 
+def splitUIAElementAttribs(attribsString):
+	"""Split an UIA Element attributes string into a dict of attribute keys and values.
+	An invalid attributes string does not cause an error, but strange results may be returned.
+	@param attribsString: The UIA Element attributes string to convert.
+	@type attribsString: str
+	@return: A dict of the attribute keys and values, where values are strings
+	@rtype: {str: str}
+	"""
+	attribsDict = {}
+	tmp = ""
+	key = ""
+	inEscape = False
+	for char in attribsString:
+		if inEscape:
+			tmp += char
+			inEscape = False
+		elif char == "\\":
+			inEscape = True
+		elif char == "=":
+			# We're about to move on to the value, so save the key and clear tmp.
+			key = tmp
+			tmp = ""
+		elif char == ";":
+			# We're about to move on to a new attribute.
+			if key:
+				# Add this key/value pair to the dict.
+				attribsDict[key] = tmp
+			key = ""
+			tmp = ""
+		else:
+			tmp += char
+	# If there was no trailing semi-colon, we need to handle the last attribute.
+	if key:
+		# Add this key/value pair to the dict.
+		attribsDict[key] = tmp
+	return attribsDict
+
 class EdgeTextInfo(UIATextInfo):
 
 	def _get_UIAElementAtStartWithReplacedContent(self):
@@ -102,6 +139,8 @@ def _getControlFieldForObject(self,obj,isEmbedded=False,startOfNode=False,endOfN
 			field['states'].add(controlTypes.STATE_EDITABLE)
 		# report if the field is 'current'
 		field['current']=obj.isCurrent
+		if obj.placeholder and obj._isTextEmpty:
+			field['placeholder']=obj.placeholder
 		# For certain controls, if ARIA overrides the label, then force the field's content (value) to the label
 		# Later processing in Edge's getTextWithFields will remove descendant content from fields with a content attribute.
 		ariaProperties=obj._getUIACacheablePropertyValue(UIAHandler.UIA_AriaPropertiesPropertyId)
@@ -409,6 +448,9 @@ def _get_description(self):
 				pass
 		return super(EdgeNode,self).description
 
+	def _get_ariaProperties(self):
+		return splitUIAElementAttribs(self.UIAElement.currentAriaProperties)
+
 	# RegEx to get the value for the aria-current property. This will be looking for a the value of 'current'
 	# in a list of strings like "something=true;current=date;". We want to capture one group, after the '='
 	# character and before the ';' character.
@@ -425,6 +467,29 @@ def _get_isCurrent(self):
 			return valueOfAriaCurrent
 		return False
 
+	def _get_placeholder(self):
+		ariaPlaceholder = self.ariaProperties.get('placeholder', None)
+		return ariaPlaceholder
+
+	def _get__isTextEmpty(self):
+		# NOTE: we can not check the result of the EdgeTextInfo move implementation to determine if we added
+		# any characters to the range, since it seems to return 1 even when the text property has not changed.
+		# Also we can not move (repeatedly by one character) since this can overrun the end of the field in edge.
+		# So instead, we use self to make a text info (which should have the right range) and then use the UIA
+		# specific _rangeObj.getText function to get a subset of the full range of characters.
+		ti = self.makeTextInfo(self)
+		if ti.isCollapsed:
+			# it is collapsed therefore it is empty.
+			# exit early so we do not have to do not have to fetch `ti.text` which
+			# is potentially costly to performance.
+			return True
+		numberOfCharacters = 2
+		text = ti._rangeObj.getText(numberOfCharacters)
+		# Edge can report newline for empty fields:
+		if text == "\n":
+			return True
+		return False
+
 class EdgeList(EdgeNode):
 
 	# non-focusable lists are readonly lists (ensures correct NVDA presentation category)

source/NVDAObjects/__init__.py

@@ -818,6 +818,15 @@ def reportFocus(self):
 		"""
 		speech.speakObject(self,reason=controlTypes.REASON_FOCUS)
 
+	def _get_placeholder(self):
+		"""If it exists for this object get the value of the placeholder text.
+		For example this might be the aria-placeholder text for a field in a web page.
+		@return: the placeholder text else None
+		@rtype: String or None
+		"""
+		log.debug("Potential unimplemented child class: %r" %self)
+		return None
+
 	def _reportErrorInPreviousWord(self):
 		try:
 			# self might be a descendant of the text control; e.g. Symphony.
@@ -972,6 +981,14 @@ def _get_basicText(self):
 	def makeTextInfo(self,position):
 		return self.TextInfo(self,position)
 
+	def _get__isTextEmpty(self):
+		"""
+		@return C{True} if the text contained in the object is considered empty by the underlying implementation. In most cases this will match {isCollapsed}, however some implementations may consider a single space or line feed as an empty range.
+		"""
+		ti = self.makeTextInfo(textInfos.POSITION_FIRST)
+		ti.move(textInfos.UNIT_CHARACTER, 1, endPoint="end")
+		return ti.isCollapsed
+
 	@staticmethod
 	def _formatLongDevInfoString(string, truncateLen=250):
 		"""Format a potentially long string value for inclusion in devInfo.

source/braille.py

@@ -661,6 +661,9 @@ def getBrailleTextForProperties(**propertyValues):
 		except KeyError:
 			log.debugWarning("Aria-current value not handled: %s"%current)
 			textList.append(controlTypes.isCurrentLabels[True])
+	placeholder = propertyValues.get('placeholder', None)
+	if placeholder:
+		textList.append(placeholder)
 	if includeTableCellCoords and  cellCoordsText:
 		textList.append(cellCoordsText)
 	return TEXT_SEPARATOR.join([x for x in textList if x])
@@ -686,7 +689,14 @@ def update(self):
 		obj = self.obj
 		presConfig = config.conf["presentation"]
 		role = obj.role
-		text = getBrailleTextForProperties(name=obj.name, role=role, roleText=obj.roleText, current=obj.isCurrent,
+		placeholderValue = obj.placeholder
+		if placeholderValue and not obj._isTextEmpty:
+			placeholderValue = None
+		text = getBrailleTextForProperties(
+			name=obj.name,
+			role=role,
+			current=obj.isCurrent,
+			placeholder=placeholderValue,
 			value=obj.value if not NVDAObjectHasUsefulText(obj) else None ,
 			states=obj.states,
 			description=obj.description if presConfig["reportObjectDescriptions"] else None,
@@ -730,6 +740,7 @@ def getControlFieldBraille(info, field, ancestors, reportStart, formatConfig):
 	states = field.get("states", set())
 	value=field.get('value',None)
 	current=field.get('current', None)
+	placeholder=field.get('placeholder', None)
 
 	if presCat == field.PRESCAT_LAYOUT:
 		text = []
@@ -760,7 +771,7 @@ def getControlFieldBraille(info, field, ancestors, reportStart, formatConfig):
 			# Don't report the role for math here.
 			# However, we still need to pass it (hence "_role").
 			"_role" if role == controlTypes.ROLE_MATH else "role": role,
-			"states": states,"value":value, "current":current}
+			"states": states,"value":value, "current":current, "placeholder":placeholder}
 		if config.conf["presentation"]["reportKeyboardShortcuts"]:
 			kbShortcut = field.get("keyboardShortcut")
 			if kbShortcut:

source/speech.py

@@ -305,11 +305,24 @@ def speakObjectProperties(obj,reason=controlTypes.REASON_QUERY,index=None,**allo
 		except NotImplementedError:
 			pass
 	newPropertyValues['current']=obj.isCurrent
+	if allowedProperties.get('placeholder', False):
+		newPropertyValues['placeholder']=obj.placeholder
 	#Get the speech text for the properties we want to speak, and then speak it
 	text=getSpeechTextForProperties(reason,**newPropertyValues)
 	if text:
 		speakText(text,index=index)
 
+def _speakPlaceholderIfEmpty(info, obj, reason):
+	""" attempt to speak placeholder attribute if the textInfo 'info' is empty
+	@return: True if info was considered empty, and we attempted to speak the placeholder value.
+	False if info was not considered empty.
+	"""
+	textEmpty = obj._isTextEmpty
+	if textEmpty:
+		speakObjectProperties(obj,reason=reason,placeholder=True)
+		return True
+	return False
+
 def speakObject(obj,reason=controlTypes.REASON_QUERY,index=None):
 	from NVDAObjects import NVDAObjectTextInfo
 	role=obj.role
@@ -357,14 +370,17 @@ def speakObject(obj,reason=controlTypes.REASON_QUERY,index=None):
 		try:
 			info=obj.makeTextInfo(textInfos.POSITION_SELECTION)
 			if not info.isCollapsed:
+				# if there is selected text, then there is a value and we do not report placeholder
 				# Translators: This is spoken to indicate what has been selected. for example 'selected hello world'
 				speakSelectionMessage(_("selected %s"),info.text)
 			else:
 				info.expand(textInfos.UNIT_LINE)
+				_speakPlaceholderIfEmpty(info, obj, reason)
 				speakTextInfo(info,unit=textInfos.UNIT_LINE,reason=controlTypes.REASON_CARET)
 		except:
 			newInfo=obj.makeTextInfo(textInfos.POSITION_ALL)
-			speakTextInfo(newInfo,unit=textInfos.UNIT_PARAGRAPH,reason=controlTypes.REASON_CARET)
+			if not _speakPlaceholderIfEmpty(newInfo, obj, reason):
+				speakTextInfo(newInfo,unit=textInfos.UNIT_PARAGRAPH,reason=controlTypes.REASON_CARET)
 	elif role==controlTypes.ROLE_MATH:
 		import mathPres
 		mathPres.ensureInit()
@@ -1007,6 +1023,9 @@ def getSpeechTextForProperties(reason=controlTypes.REASON_QUERY,**propertyValues
 		except KeyError:
 			log.debugWarning("Aria-current value not handled: %s"%ariaCurrent)
 			textList.append(controlTypes.isCurrentLabels[True])
+	placeholder = propertyValues.get('placeholder', None)
+	if placeholder:
+		textList.append(placeholder)
 	indexInGroup=propertyValues.get('positionInfo_indexInGroup',0)
 	similarItemsInGroup=propertyValues.get('positionInfo_similarItemsInGroup',0)
 	if 0<indexInGroup<=similarItemsInGroup:
@@ -1042,6 +1061,7 @@ def getControlFieldSpeech(attrs,ancestorAttrs,fieldType,formatConfig=None,extraD
 	states=attrs.get('states',set())
 	keyboardShortcut=attrs.get('keyboardShortcut', "")
 	ariaCurrent=attrs.get('current', None)
+	placeholderValue=attrs.get('placeholder', None)
 	value=attrs.get('value',"")
 	if reason==controlTypes.REASON_FOCUS or attrs.get('alwaysReportDescription',False):
 		description=attrs.get('description',"")
@@ -1058,6 +1078,7 @@ def getControlFieldSpeech(attrs,ancestorAttrs,fieldType,formatConfig=None,extraD
 	stateText=getSpeechTextForProperties(reason=reason,states=states,_role=role)
 	keyboardShortcutText=getSpeechTextForProperties(reason=reason,keyboardShortcut=keyboardShortcut) if config.conf["presentation"]["reportKeyboardShortcuts"] else ""
 	ariaCurrentText=getSpeechTextForProperties(reason=reason,current=ariaCurrent)
+	placeholderText=getSpeechTextForProperties(reason=reason,placeholder=placeholderValue)
 	nameText=getSpeechTextForProperties(reason=reason,name=name)
 	valueText=getSpeechTextForProperties(reason=reason,value=value)
 	descriptionText=(getSpeechTextForProperties(reason=reason,description=description)
@@ -1121,6 +1142,10 @@ def getControlFieldSpeech(attrs,ancestorAttrs,fieldType,formatConfig=None,extraD
 		content = attrs.get("content")
 		if content and speakContentFirst:
 			out.append(content)
+		if placeholderValue:
+			if valueText:
+				log.error("valueText exists when expected none: valueText:'%s' placeholderText:'%s'"%(valueText,placeholderText))
+			valueText = placeholderText
 		out.extend(x for x in (nameText,(stateText if speakStatesFirst else roleText),(roleText if speakStatesFirst else stateText),ariaCurrentText,valueText,descriptionText,levelText,keyboardShortcutText) if x)
 		if content and not speakContentFirst:
 			out.append(content)

source/virtualBuffers/MSHTML.py

@@ -53,6 +53,9 @@ def _normalizeControlField(self,attrs):
 		ariaCurrent = attrs.get('HTMLAttrib::aria-current', None)
 		if ariaCurrent is not None:
 			attrs['current']=ariaCurrent
+		placeholder = self._getPlaceholderAttribute(attrs, 'HTMLAttrib::aria-placeholder')
+		if placeholder:
+			attrs['placeholder']=placeholder
 		accRole=attrs.get('IAccessible::role',0)
 		accRole=int(accRole) if isinstance(accRole,basestring) and accRole.isdigit() else accRole
 		nodeName=attrs.get('IHTMLDOMNode::nodeName',"")

source/virtualBuffers/__init__.py

@@ -218,6 +218,38 @@ def _getTextRange(self,start,end):
 			return u""
 		return NVDAHelper.VBuf_getTextInRange(self.obj.VBufHandle,start,end,False) or u""
 
+	def _getPlaceholderAttribute(self, attrs, placeholderAttrsKey):
+		"""Gets the placeholder attribute to be used.
+		@return: The placeholder attribute when there is no content within the ControlField.
+		None when the ControlField has content.
+		@note: The content is considered empty if it holds a single space.
+		"""
+		placeholder = attrs.get(placeholderAttrsKey)
+		# For efficiency, only check if it is valid to return placeholder when we have a placeholder value to return.
+		if not placeholder:
+			return None
+		# Get the start and end offsets for the field. This can be used to check if the field has any content.
+		try:
+			start, end = self._getOffsetsFromFieldIdentifier(
+				int(attrs.get('controlIdentifier_docHandle')),
+				int(attrs.get('controlIdentifier_ID')))
+		except (LookupError, ValueError):
+			log.debugWarning("unable to get offsets used to fetch content")
+			return placeholder
+		else:
+			valueLen = end - start
+			if not valueLen: # value is empty, use placeholder
+				return placeholder
+			# Because fetching the content of the field could result in a large amount of text
+			# we only do it in order to check for space.
+			# We first compare the length by comparing the offsets, if the length is less than 2 (ie
+			# could hold space)
+			if valueLen < 2:
+				controlFieldText = self.obj.makeTextInfo(textInfos.offsets.Offsets(start, end)).text
+				if not controlFieldText or controlFieldText == ' ':
+					return placeholder
+		return None
+
 	def getTextWithFields(self,formatConfig=None):
 		start=self._startOffset
 		end=self._endOffset

source/virtualBuffers/gecko_ia2.py

@@ -23,9 +23,12 @@
 class Gecko_ia2_TextInfo(VirtualBufferTextInfo):
 
 	def _normalizeControlField(self,attrs):
-		ariaCurrent = attrs.get("IAccessible2::attribute_current")
-		if ariaCurrent != None:
-			attrs['current']= ariaCurrent
+		current = attrs.get("IAccessible2::attribute_current")
+		if current is not None:
+			attrs['current']= current
+		placeholder = self._getPlaceholderAttribute(attrs, "IAccessible2::attribute_placeholder")
+		if placeholder is not None:
+			attrs['placeholder']= placeholder
 		accRole=attrs['IAccessible::role']
 		accRole=int(accRole) if accRole.isdigit() else accRole
 		role=IAccessibleHandler.IAccessibleRolesToNVDARoles.get(accRole,controlTypes.ROLE_UNKNOWN)