def onStrokeAdded( self, stroke ):
"Watches for Strokes that look like an arrow to Annotate"
ep1 = stroke.Points[0]
ep2 = stroke.Points[-1]
isArrowHead = False
GeomUtils.ellipseAxisRatio(stroke)
#Match single-stroke arrows
tip, tail = _isSingleStrokeArrow(stroke)
if tip is None or tail is None:
revpts = list(stroke.Points)
revpts.reverse()
tip, tail = _isSingleStrokeArrow(Stroke(revpts))
if tip is not None and tail is not None:
isArrowHead = False
anno = ArrowAnnotation( tip, tail )
BoardSingleton().AnnotateStrokes( [stroke], anno)
else:
return
if _isArrowHead(stroke, self.arrowHeadMatcher): #We've matched an arrowhead
head = stroke
isArrowHead = True
strokeNorm = GeomUtils.strokeNormalizeSpacing(stroke, numpoints = 5)
tip = strokeNorm.Points[2] #Middle normalized point is the tip
#Match it to any tails we have
if isArrowHead:
matchedTails = self._matchHeadtoTail(head = stroke, point = tip)
for headpoint, tail in matchedTails:
#Orient the tail correctly
if tail.Points[0] == headpoint:
endpoint = tail.Points[-1]
else:
endpoint = tail.Points[0]
anno = ArrowAnnotation(tip, endpoint)
BoardSingleton().AnnotateStrokes([head, tail],anno)
#Match it like a tail even if we think it's an arrowhead. Oh ambiguity!
matchedHeads = self._matchHeadtoTail(tail = stroke, point = ep1)
for tip, head in matchedHeads:
anno = ArrowAnnotation(tip, ep2)
BoardSingleton().AnnotateStrokes([head, stroke],anno)
matchedHeads = self._matchHeadtoTail(tail = stroke, point = ep2)
for tip, head in matchedHeads:
anno = ArrowAnnotation(tip, ep1)
BoardSingleton().AnnotateStrokes([head, stroke],anno)
#Add this stroke to the pool for future evaluation
self._endpoints.append( (ep1, stroke) )
self._endpoints.append( (ep2, stroke) )
if isArrowHead:
self._arrowHeads.append( (tip, stroke) )
