Uniform Font Size Across Various Display Types

[capn-freako]

Describe the desired new or improved feature.
The plot text is very small, on a 4K laptop monitor.
Can the text size of PyBERT labels be regularized across display types somehow?

Expected behavior
Text size appears the same, no matter the display resolution.

Screenshots
(n/a)

Desktop (please complete the following information):

• OS: Windows 10
• Python Version 3.7.6
• PyBERT Version 3.3.2

Additional context
Original Issue on Chaco GitHub site

[capn-freako]

I've experimented with explicitly specifying the ETS toolkit with varying degrees of success:

from traits.etsconfig.api import ETSConfig
# ETSConfig.toolkit = 'qt.celiagg'  # Yields unacceptably small font sizes in plot axis labels.
# ETSConfig.toolkit = 'qt.qpainter'  # Was causing crash on Mac.

[capn-freako]

I asked about this on StackOverflow:
https://stackoverflow.com/questions/60415306/how-to-automatically-accommodate-different-display-resolutions-in-chaco-plots

[capn-freako]

Here is some documentation on setting the ETS toolkit:
https://docs.enthought.com/pyface/toolkits.html

It offers this suggestion:

by setting the environment variable ETS_TOOLKIT to the name of the desired toolkit.

So, I tried that:

(pybert-dev)
capnf@DESKTOP-G84ND7C MINGW64 ~/Documents/GitHub/PyBERT (master)
$ echo $ETS_TOOLKIT
qt5

==> See this comment by Corran Webster, re: the use of "qt5".

But, it yields this error:

(pybert-dev)
capnf@DESKTOP-G84ND7C MINGW64 ~/Documents/GitHub/PyBERT (master)
$ python -m pybert &
[1] 3980
(pybert-dev)
capnf@DESKTOP-G84ND7C MINGW64 ~/Documents/GitHub/PyBERT (master)
$ Traceback (most recent call last):
  File "C:\Users\capnf\anaconda3\envs\pybert-dev\lib\runpy.py", line 194, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "C:\Users\capnf\anaconda3\envs\pybert-dev\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "C:\Users\capnf\Documents\GitHub\PyBERT\pybert\__main__.py", line 2, in <module>
    from pybert.pybert      import PyBERT
  File "C:\Users\capnf\Documents\GitHub\PyBERT\pybert\pybert.py", line 29, in <module>
    from chaco.api import ArrayPlotData, GridPlotContainer
  File "C:\Users\capnf\anaconda3\envs\pybert-dev\lib\site-packages\chaco\api.py", line 314, in <module>
    from .plots.horizon_plot import BandedMapper
  File "C:\Users\capnf\anaconda3\envs\pybert-dev\lib\site-packages\chaco\plots\horizon_plot.py", line 14, in <module>
    from enable.api import transparent_color_trait
  File "C:\Users\capnf\anaconda3\envs\pybert-dev\lib\site-packages\enable\api.py", line 184, in <module>
    from .base import (
  File "C:\Users\capnf\anaconda3\envs\pybert-dev\lib\site-packages\enable\base.py", line 41, in <module>
    from .colors import color_table, transparent_color
  File "C:\Users\capnf\anaconda3\envs\pybert-dev\lib\site-packages\enable\colors.py", line 287, in <module>
    from traitsui.qt4.color_editor import (
  File "C:\Users\capnf\anaconda3\envs\pybert-dev\Lib\site-packages\shiboken2\files.dir\shibokensupport\feature.py", line 139, in _import
    return original_import(name, *args, **kwargs)
  File "C:\Users\capnf\anaconda3\envs\pybert-dev\lib\site-packages\traitsui\qt4\__init__.py", line 35, in <module>
    from . import toolkit
  File "C:\Users\capnf\anaconda3\envs\pybert-dev\Lib\site-packages\shiboken2\files.dir\shibokensupport\feature.py", line 139, in _import
    return original_import(name, *args, **kwargs)
  File "C:\Users\capnf\anaconda3\envs\pybert-dev\lib\site-packages\traitsui\qt4\toolkit.py", line 31, in <module>
    assert_toolkit_import(["qt4", "qt"])
  File "C:\Users\capnf\anaconda3\envs\pybert-dev\lib\site-packages\traitsui\toolkit.py", line 39, in assert_toolkit_import
    raise RuntimeError(
RuntimeError: Importing from qt4 backend after selecting qt5 backend!

It looks like the enable package might be enforcing usage of Qt4!
I do build a custom version of enable.
Maybe, I need to rebuild it to use Qt5?

==> Nope. See this comment by Corran Webster.

[capn-freako]

Here's another page on explicitly defining the toolkit, this one from Enable's perspective:
https://docs.enthought.com/enable/enable/toolkit_selection.html

It offers this handy tip:

If you wish to test toolkit/backend combinations without the need for code modifications, you can set the ETS_TOOLKIT environment variable before running your application. ETSConfig will use the value of that environment variable to initialize its toolkit and kiva_backend properties. Here’s what that looks like:

$ export ETS_TOOLKIT=qt.qpainter
$ python kiva/examples/kiva/kiva_explorer.py