#203 run time option to disable use of PyQt should be added

[Jack Howarth]

Since the new PyQt support prevents the use of tkinter based modules in pymol, there should be a run time command line option added to allow the use of the PyQt interface to be disabled. Otherwise users who want to use the tkinter based modules will have to continually watch that PyQt doesn't get installed on their machines.

[Jack Howarth]

Note that the MacPorts test packaging for pymol 2.1.0 at https://trac.macports.org/ticket/56139 reveals that when built for X11 tk support, the resulting pymol, when started in the presence of PyQt, will fail to properly initialize its GL support....

Detected OpenGL version 2.0 or greater. Shaders available.
Detected GLSL version 0.0.
OpenGL graphics engine:
GL_VENDOR: (null)
GL_RENDERER: (null)
GL_VERSION: (null)
Detected 8 CPU cores. Enabled multithreaded rendering.

Deinstalling the PyQt package in MacPorts eliminates this issue.

Detected OpenGL version 2.0 or greater. Shaders available.
Detected GLSL version 1.20.
OpenGL graphics engine:
GL_VENDOR: ATI Technologies Inc.
GL_RENDERER: ATI Radeon HD 2600 OpenGL Engine
GL_VERSION: 2.1 ATI-10.4.14
Adjusting settings to improve performance for ATI cards.
Detected 8 CPU cores. Enabled multithreaded rendering.

[Thomas Holder]

It's possible to select the tk interface over pyqt at run time like this:

pymol -N pmg_tk