# Orca
#
# Copyright (C) 2011-2013 Igalia, S.L.
#
# Author: Joanmarie Diggs <jdiggs@igalia.com>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., Franklin Street, Fifth Floor,
# Boston MA 02110-1301 USA.
"""Heuristic means to infer the functional/displayed label of a widget."""
__id__ = "$Id$"
__version__ = "$Revision$"
__date__ = "$Date$"
__copyright__ = "Copyright (C) 2011-2013 Igalia, S.L."
__license__ = "LGPL"
import pyatspi
from . import debug
class LabelInference:
def __init__(self, script):
"""Creates an instance of the LabelInference class.
Arguments:
- script: the script with which this instance is associated.
"""
self._script = script
self._lineCache = {}
self._extentsCache = {}
self._isWidgetCache = {}
def infer(self, obj, focusedOnly=True):
"""Attempt to infer the functional/displayed label of obj.
Arguments
- obj: the unlabeled widget
- focusedOnly: If True, only infer if the widget has focus.
Returns the text which we think is the label, or None.
"""
debug.println(debug.LEVEL_INFO, "INFER label for: %s" % obj, True)
if not obj:
return None, []
if focusedOnly and not obj.getState().contains(pyatspi.STATE_FOCUSED):
debug.println(debug.LEVEL_INFO, "INFER - object not focused", True)
return None, []
result, objects = None, []
if not result:
result, objects = self.inferFromTextLeft(obj)
debug.println(debug.LEVEL_INFO, "INFER - Text Left: %s" % result, True)
if not result or self._preferRight(obj):
result, objects = self.inferFromTextRight(obj) or result
debug.println(debug.LEVEL_INFO, "INFER - Text Right: %s" % result, True)
if not result:
result, objects = self.inferFromTable(obj)
debug.println(debug.LEVEL_INFO, "INFER - Table: %s" % result, True)
if not result:
result, objects = self.inferFromTextAbove(obj)
debug.println(debug.LEVEL_INFO, "INFER - Text Above: %s" % result, True)
if not result:
result, objects = self.inferFromTextBelow(obj)
debug.println(debug.LEVEL_INFO, "INFER - Text Below: %s" % result, True)
# TODO - We probably do not wish to "infer" from these. Instead, we
# should ensure that this content gets presented as part of the widget.
# (i.e. the label is something on screen. Widget name and description
# are each something other than a label.)
if not result:
result, objects = obj.name, []
debug.println(debug.LEVEL_INFO, "INFER - Name: %s" % result, True)
if result:
result = result.strip()
result = result.replace("\n", " ")
# Desperate times call for desperate measures....
if not result:
result, objects = self.inferFromTextLeft(obj, proximity=200)
debug.println(debug.LEVEL_INFO, "INFER - Text Left with proximity of 200: %s" % result, True)
self.clearCache()
return result, objects
def clearCache(self):
"""Dumps whatever we've stored for performance purposes."""
self._lineCache = {}
self._extentsCache = {}
self._isWidgetCache = {}
def _preferRight(self, obj):
"""Returns True if we should prefer text on the right, rather than the
left, for the object obj."""
onRightRoles = [pyatspi.ROLE_CHECK_BOX, pyatspi.ROLE_RADIO_BUTTON]
return obj.getRole() in onRightRoles
def _preventRight(self, obj):
"""Returns True if we should not permit inference based on text to
the right for the object obj."""
roles = [pyatspi.ROLE_COMBO_BOX,
pyatspi.ROLE_LIST,
pyatspi.ROLE_LIST_BOX]
return obj.getRole() in roles
def _preferTop(self, obj):
"""Returns True if we should prefer text above, rather than below for
the object obj."""
roles = [pyatspi.ROLE_COMBO_BOX,
pyatspi.ROLE_LIST,
pyatspi.ROLE_LIST_BOX]
return obj.getRole() in roles
def _preventBelow(self, obj):
"""Returns True if we should not permit inference based on text below
the object obj."""
roles = [pyatspi.ROLE_ENTRY,
pyatspi.ROLE_PASSWORD_TEXT]
return obj.getRole() not in roles
def _isSimpleObject(self, obj):
"""Returns True if the given object has 'simple' contents, such as text
without embedded objects or a single embedded object without text."""
if not obj:
return False
try:
children = [child for child in obj]
except (LookupError, RuntimeError):
debug.println(debug.LEVEL_INFO, 'Dead Accessible in %s' % obj, True)
return False
children = [x for x in children if x.getRole() != pyatspi.ROLE_LINK]
if len(children) > 1:
return False
try:
text = obj.queryText()
except NotImplementedError:
return True
string = text.getText(0, -1).strip()
if string.count(self._script.EMBEDDED_OBJECT_CHARACTER) > 1:
return False
return True
def _cannotLabel(self, obj):
"""Returns True if the given object should not be treated as a label."""
if not obj:
return True
nonLabelTextRoles = [pyatspi.ROLE_HEADING, pyatspi.ROLE_LIST_ITEM]
if obj.getRole() in nonLabelTextRoles:
return True
return self._isWidget(obj)
def _isWidget(self, obj):
"""Returns True if the given object is a widget."""
if not obj:
return False
rv = self._isWidgetCache.get(hash(obj))
if rv is not None:
return rv
widgetRoles = [pyatspi.ROLE_CHECK_BOX,
pyatspi.ROLE_RADIO_BUTTON,
pyatspi.ROLE_TOGGLE_BUTTON,
pyatspi.ROLE_COMBO_BOX,
pyatspi.ROLE_LIST,
pyatspi.ROLE_LIST_BOX,
pyatspi.ROLE_MENU,
pyatspi.ROLE_MENU_ITEM,
pyatspi.ROLE_ENTRY,
pyatspi.ROLE_PASSWORD_TEXT,
pyatspi.ROLE_PUSH_BUTTON]
isWidget = obj.getRole() in widgetRoles
if not isWidget and obj.getState().contains(pyatspi.STATE_EDITABLE):
isWidget = True
self._isWidgetCache[hash(obj)] = isWidget
return isWidget
def _getExtents(self, obj, startOffset=0, endOffset=-1):
"""Returns (x, y, width, height) of the text at the given offsets
if the object implements accessible text, or just the extents of
the object if it doesn't implement accessible text."""
if not obj:
return 0, 0, 0, 0
rv = self._extentsCache.get((hash(obj), startOffset, endOffset))
if rv:
return rv
extents = 0, 0, 0, 0
text = self._script.utilities.queryNonEmptyText(obj)
if text:
skipTextExtents = [pyatspi.ROLE_ENTRY, pyatspi.ROLE_PASSWORD_TEXT]
if not obj.getRole() in skipTextExtents:
if endOffset == -1:
try:
endOffset = text.characterCount
except:
msg = "ERROR: Exception getting character count for %s" % obj
debug.println(debug.LEVEL_INFO, msg, True)
return extents
extents = text.getRangeExtents(startOffset, endOffset, 0)
if not (extents[2] and extents[3]):
try:
ext = obj.queryComponent().getExtents(0)
except NotImplementedError:
msg = "INFO: %s does not implement the component interface" % obj
debug.println(debug.LEVEL_INFO, msg, True)
except:
msg = "ERROR: Exception getting extents for %s" % obj
debug.println(debug.LEVEL_INFO, msg, True)
else:
extents = ext.x, ext.y, ext.width, ext.height
self._extentsCache[(hash(obj), startOffset, endOffset)] = extents
return extents
def _createLabelFromContents(self, obj):
"""Gets the functional label text associated with the object obj."""
if not self._isSimpleObject(obj):
return None, []
if self._cannotLabel(obj):
return None, []
contents = self._script.utilities.getObjectContentsAtOffset(obj, useCache=False)
objects = [content[0] for content in contents]
if list(filter(self._isWidget, objects)):
return None, []
strings = [content[3] for content in contents]
return ''.join(strings), objects
def _getLineContents(self, obj, start=0):
"""Get the (obj, startOffset, endOffset, string) tuples for the line
containing the object, obj."""
rv = self._lineCache.get(hash(obj))
if rv:
return rv
key = hash(obj)
if self._isWidget(obj):
start, end = self._script.utilities.getHyperlinkRange(obj)
obj = obj.parent
rv = self._script.utilities.getLineContentsAtOffset(obj, start, True, False)
self._lineCache[key] = rv
return rv
def inferFromTextLeft(self, obj, proximity=75):
"""Attempt to infer the functional/displayed label of obj by
looking at the contents of the current line, which are to the
left of this object
Arguments
- obj: the unlabeled widget
- proximity: pixels expected for a match
Returns the text which we think is the label, or None.
"""
extents = self._getExtents(obj)
contents = self._getLineContents(obj)
content = [o for o in contents if o[0] == obj]
try:
index = contents.index(content[0])
except IndexError:
index = len(contents)
onLeft = contents[0:index]
start = 0
for i in range(len(onLeft) - 1, -1, -1):
lObj, lStart, lEnd, lString = onLeft[i]
lExtents = self._getExtents(lObj)
if lExtents[0] > extents[0] or self._cannotLabel(lObj):
start = i + 1
break
onLeft = onLeft[start:]
if not (onLeft and onLeft[0]):
return None, []
lObj, start, end, string = onLeft[-1]
lExtents = self._getExtents(lObj, start, end)
distance = extents[0] - (lExtents[0] + lExtents[2])
if 0 <= distance <= proximity:
strings = [content[3] for content in onLeft]
result = ''.join(strings).strip()
if result:
return result, [content[0] for content in onLeft]
return None, []
def inferFromTextRight(self, obj, proximity=25):
"""Attempt to infer the functional/displayed label of obj by
looking at the contents of the current line, which are to the
right of this object
Arguments
- obj: the unlabeled widget
- proximity: pixels expected for a match
Returns the text which we think is the label, or None.
"""
if self._preventRight(obj):
return None, []
extents = self._getExtents(obj)
contents = self._getLineContents(obj)
content = [o for o in contents if o[0] == obj]
try:
index = contents.index(content[0])
except IndexError:
index = len(contents)
onRight = contents[min(len(contents), index+1):]
end = len(onRight)
for i, item in enumerate(onRight):
if self._cannotLabel(item[0]):
if not self._preferRight(obj):
return None, []
end = i + 1
break
onRight = onRight[0:end]
if not (onRight and onRight[0]):
return None, []
rObj, start, end, string = onRight[0]
rExtents = self._getExtents(rObj, start, end)
distance = rExtents[0] - (extents[0] + extents[2])
if distance <= proximity or self._preferRight(obj):
strings = [content[3] for content in onRight]
result = ''.join(strings).strip()
if result:
return result, [content[0] for content in onRight]
return None, []
def inferFromTextAbove(self, obj, proximity=20):
"""Attempt to infer the functional/displayed label of obj by
looking at the contents of the line above the line containing
the object obj.
Arguments
- obj: the unlabeled widget
- proximity: pixels expected for a match
Returns the text which we think is the label, or None.
"""
thisLine = self._getLineContents(obj)
content = [o for o in thisLine if o[0] == obj]
try:
index = thisLine.index(content[0])
except IndexError:
return None, []
if index > 0:
return None, []
prevObj, prevOffset = self._script.utilities.previousContext(
thisLine[0][0], thisLine[0][1], True)
prevLine = self._getLineContents(prevObj, prevOffset)
if len(prevLine) != 1:
return None, []
prevObj, start, end, string = prevLine[0]
if self._cannotLabel(prevObj):
return None, []
if string.strip():
x, y, width, height = self._getExtents(prevObj, start, end)
objX, objY, objWidth, objHeight = self._getExtents(obj)
distance = objY - (y + height)
if 0 <= distance <= proximity and x <= objX:
return string.strip(), [prevObj]
return None, []
def inferFromTextBelow(self, obj, proximity=20):
"""Attempt to infer the functional/displayed label of obj by
looking at the contents of the line above the line containing
the object obj.
Arguments
- obj: the unlabeled widget
- proximity: pixels expected for a match
Returns the text which we think is the label, or None.
"""
if self._preventBelow(obj):
return None, []
thisLine = self._getLineContents(obj)
content = [o for o in thisLine if o[0] == obj]
try:
index = thisLine.index(content[0])
except IndexError:
return None, []
if index > 0:
return None, []
nextObj, nextOffset = self._script.utilities.nextContext(
thisLine[-1][0], thisLine[-1][2] - 1, True)
nextLine = self._getLineContents(nextObj, nextOffset)
if len(nextLine) != 1:
return None, []
nextObj, start, end, string = nextLine[0]
if self._cannotLabel(nextObj):
return None, []
if string.strip():
x, y, width, height = self._getExtents(nextObj, start, end)
objX, objY, objWidth, objHeight = self._getExtents(obj)
distance = y - (objY + objHeight)
if 0 <= distance <= proximity:
return string.strip(), [nextObj]
return None, []
def inferFromTable(self, obj, proximityForRight=50):
"""Attempt to infer the functional/displayed label of obj by looking
at the contents of the surrounding table cells. Note that this approach
assumes a simple table in which the widget is the sole occupant of its
cell.
Arguments
- obj: the unlabeled widget
Returns the text which we think is the label, or None.
"""
pred = lambda x: x.getRole() == pyatspi.ROLE_TABLE_CELL
cell = pyatspi.utils.findAncestor(obj, pred)
if not self._isSimpleObject(cell):
return None, []
if not cell in [obj.parent, obj.parent.parent]:
return None, []
pred = lambda x: x.getRole() == pyatspi.ROLE_TABLE
grid = pyatspi.utils.findAncestor(cell, pred)
if not grid:
return None, []
try:
table = grid.queryTable()
except NotImplementedError:
return None, []
index = self._script.utilities.cellIndex(cell)
row = table.getRowAtIndex(index)
col = table.getColumnAtIndex(index)
objX, objY, objWidth, objHeight = self._getExtents(obj)
if col > 0 and not self._preferRight(obj):
candidate = table.getAccessibleAt(row, col - 1)
label, sources = self._createLabelFromContents(candidate)
if label:
return label.strip(), sources
if col < table.nColumns and not self._preventRight(obj):
candidate = table.getAccessibleAt(row, col + 1)
x, y, width, height = self._getExtents(candidate)
distance = x - (objX + objWidth)
if distance <= proximityForRight or self._preferRight(obj):
label, sources = self._createLabelFromContents(candidate)
if label:
return label.strip(), sources
cellAbove = cellBelow = labelAbove = labelBelow = None
if row > 0:
cellAbove = table.getAccessibleAt(row - 1, col)
labelAbove, sourcesAbove = self._createLabelFromContents(cellAbove)
if labelAbove and self._preferTop(obj):
return labelAbove.strip(), sourcesAbove
if row < table.nRows and not self._preventBelow(obj):
cellBelow = table.getAccessibleAt(row + 1, col)
labelBelow, sourcesBelow = self._createLabelFromContents(cellBelow)
if labelAbove and labelBelow:
aboveX, aboveY, aboveWidth, aboveHeight = self._getExtents(cellAbove)
belowX, belowY, belowWidth, belowHeight = self._getExtents(cellBelow)
dAbove = objY - (aboveY + aboveHeight)
dBelow = belowY - (objY + objHeight)
if dAbove <= dBelow:
return labelAbove.strip(), sourcesAbove
return labelBelow.strip(), sourcesBelow
if labelAbove:
return labelAbove.strip(), sourcesAbove
if labelBelow:
return labelBelow.strip(), sourcesBelow
# None of the cells immediately surrounding this cell seem to be serving
# as a functional label. Therefore, see if this table looks like a grid
# of widgets with the functional labels in the first row.
firstRow = [table.getAccessibleAt(0, i) for i in range(table.nColumns)]
if not firstRow or list(filter(self._isWidget, firstRow)):
return None, []
cells = [table.getAccessibleAt(i, col) for i in range(1, table.nRows)]
cells = [x for x in cells if x is not None]
if [x for x in cells if x.childCount and x[0].getRole() != obj.getRole()]:
return None, []
label, sources = self._createLabelFromContents(firstRow[col])
if label:
return label.strip(), sources
return None, []