[gt-users] custom-track memory leak

[Troels Marstrand]

I am trying to replicate the custom track example from the python  
tutorial pages, however, I get to following error message:

/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site- 
packages/gt/annotationsketch/layout.py:51: RuntimeWarning: memory leak  
in callback function.
   had_err = gtlib.gt_layout_sketch(self.layout, canvas, err)

Here is a copy of the python script I am using:

#!/usr/bin/python

#import genometools
from gt.core import *
from gt.extended import *
from gt.annotationsketch import *
from gt.annotationsketch.custom_track import CustomTrack
from gt.core.gtrange import Range

class CustomTrackInsertions(CustomTrack):
   def __init__(self, sidelength, data):
     super(CustomTrackInsertions, self).__init__()
     self.sidelength = sidelength
     self.data = data

   def get_height(self):
     return 20

   def get_title(self):
     return "Insertion site"

   def render(self, graphics, ypos, rng, style, error):
     height = (self.sidelength*math.sqrt(3))/2
     margins = graphics.get_xmargins()
     red = Color(1, 0, 0, 0.7)
     for pos, desc in self.data.iteritems():
       drawpos = margins + (float(pos)-rng.start)/(rng.end-rng.start 
+1)         \
                   * (graphics.get_image_width()-2*margins)
       graphics.draw_line(drawpos-self.sidelength/2, ypos +  
height,             \
                          drawpos,  
ypos,                                        \
                          red, 1)
       graphics.draw_line(drawpos,  
ypos,                                        \
                          drawpos+self.sidelength/2, ypos +  
height,             \
                          red, 1)
       graphics.draw_line(drawpos-self.sidelength/2, ypos +  
height,             \
                          drawpos+self.sidelength/2, ypos +  
height,             \
                          red, 1)
       graphics.draw_text_centered(drawpos, ypos + height + 13,  
str(desc))
     return 0

style = Style()
style.load_file('default.style')
feature_index = FeatureIndexMemory()
feature_index.add_gff3file('tmp.gff3')
seqid = feature_index.get_first_seqid()
range = feature_index.get_range_for_seqid(seqid)
diagram = Diagram.from_index(feature_index, seqid, range, style)
ctt = CustomTrackInsertions(15, {67100417:"foo", 67113051:"bar",  
67143471:"baz"})
diagram.add_custom_track(ctt)
layout = Layout(diagram, 600, style)
height = layout.get_height()
canvas = CanvasCairoFile(style, 600, height)
layout.sketch(canvas)

Thanks in advance for any help

Cheers
Troels