self._positions is None

[gokhan_tolun@…]

The following bug report has been submitted:
Platform:        Windows-10-10.0.17763
ChimeraX Version: 0.91 (2019-06-25)
Description
Opened a DNA molecule and chose Tube/slab from the Nucleotides tab.

Log:
UCSF ChimeraX version: 0.91 (2019-06-25)  
© 2016-2019 Regents of the University of California. All rights reserved.  
How to cite UCSF ChimeraX  

> open "C:\\\Users\\\GokhanTolun\\\OneDrive - University of
Wollongong\\\Teaching\\\2018\\\CHEM325\\\CHEM325_Lectures\\\Structure-of-DNA,
Nucleic Acids as drug target\\\Figures\\\1aio.pdb"

Summary of feedback from opening C:\Users\GokhanTolun\OneDrive - University of
Wollongong\Teaching\2018\CHEM325\CHEM325_Lectures\Structure-of-DNA, Nucleic
Acids as drug target\Figures\1aio.pdb  
---  
notes | Combining 2 symmetry atoms into HOH /B:76 O  
Combining 2 symmetry atoms into HOH /B:51 O  
Combining 2 symmetry atoms into HOH /B:79 O  
Combining 2 symmetry atoms into HOH /B:52 O  
Combining 2 symmetry atoms into HOH /B:53 O  
26 messages similar to the above omitted  
  
1aio.pdb title:  
Crystal structure of A double-stranded DNA containing the major adduct of the
anticancer drug cisplatin [more info...]  
  
Chain information for 1aio.pdb #1  
---  
Chain | Description  
A C | DNA (5'-D(*CP*CP*(bru)P*CP*TP*[Pt(NH3)2(GP*GP) ]*TP*CP*TP*CP*C)-3')  
B D | DNA (5'-D(*GP*GP*ap*GP*ap*CP*CP*ap*GP*ap*GP*G)-3')  
  
Non-standard residues in 1aio.pdb #1  
---  
BRU — 5-bromo-2'-deoxyuridine-5'-monophosphate  
CPT — cisplatin (diammine(dichloro)platinum)  
  

> nucleotides selAtoms ladder

> nucleotides selAtoms stubs

> nucleotides selAtoms ladder

> nucleotides selAtoms tube/slab shape muffler

> nucleotides selAtoms stubs

> nucleotides selAtoms ladder

> nucleotides selAtoms tube/slab shape ellipsoid

> nucleotides selAtoms tube/slab shape box

> nucleotides selAtoms slab

> style nucleic & selAtoms stick

Changed 972 atom styles  
An error occurred in drawing the scene. Redrawing graphics is now stopped to
avoid a continuous stream of error messages. To restart graphics use the
command "graphics restart" after changing the settings that caused the error.  
  
Traceback (most recent call last):  
File "C:\Program Files\ChimeraX_190625\bin\lib\site-
packages\chimerax\core\updateloop.py", line 72, in draw_new_frame  
view.draw(check_for_changes = False)  
File "C:\Program Files\ChimeraX_190625\bin\lib\site-
packages\chimerax\core\graphics\view.py", line 164, in draw  
self._draw_scene(camera, drawings)  
File "C:\Program Files\ChimeraX_190625\bin\lib\site-
packages\chimerax\core\graphics\view.py", line 226, in _draw_scene  
draw_opaque(r, opaque_drawings)  
File "C:\Program Files\ChimeraX_190625\bin\lib\site-
packages\chimerax\core\graphics\drawing.py", line 1418, in draw_opaque  
_draw_multiple(drawings, renderer, Drawing.OPAQUE_DRAW_PASS)  
File "C:\Program Files\ChimeraX_190625\bin\lib\site-
packages\chimerax\core\graphics\drawing.py", line 1429, in _draw_multiple  
d.draw(renderer, draw_pass)  
File "C:\Program Files\ChimeraX_190625\bin\lib\site-
packages\chimerax\core\graphics\drawing.py", line 711, in draw  
if not self.display:  
File "C:\Program Files\ChimeraX_190625\bin\lib\site-
packages\chimerax\core\graphics\drawing.py", line 334, in get_display  
return self._any_displayed_positions and len(self._positions) > 0  
TypeError: object of type 'NoneType' has no len()  
  




OpenGL version: 3.3.0 NVIDIA 419.67
OpenGL renderer: GeForce GTX 1060/PCIe/SSE2
OpenGL vendor: NVIDIA Corporation

[Tom Goddard]

This error means that ChimeraX attempted to draw a deleted drawing. Nucleotides deletes drawing and must have been where the drawing was deleted.

When press the exact same toolbar icons with PDB 1aoi it does not produce this error, using same ChimeraX version but on Mac not Windows. Should try on Windows but I suspect it is a timing problem (the drawing was removed at the wrong time).

[Tom Goddard]

I tried this in the same ChimeraX daily build (6/25/2019) on Windows and clicked on all the nucleotide toolbar icons and was never able to produce an error.

There must be a bug here but not able to debug it unless it can be reproduced. If you have a way to reproduce this error please tell us.

[Tom Goddard]

Fixed by #2278.