QtGui.QStyleOptionSlider: implicit conversion to float fails with Python 3.10

[osthomas]

With Python 3.10, using a traitsui BoundsEditor for a Range fails:

from traits.api import *
from traitsui.api import *
from traitsui.qt4.extra.bounds_editor import BoundsEditor


class Test(HasTraits):
    val = Range(0.3, 10.5)

    _xmin = Float(5.0)
    _xmax = Float(10.0)

    view = View(
        UItem(
            'val',
            editor=BoundsEditor(
                low_name='_xmin',
                high_name='_xmax',
                format='%.2f')
        )
    )

Test().configure_traits()

Traceback (most recent call last):
  File ".../lib/python3.10/site-packages/traitsui/qt4/extra/range_slider.py", line 81, in paintEvent
    opt.sliderPosition = value
TypeError: 'float' object cannot be interpreted as an integer

The same code works in Python 3.9.

In range_slider.py, the slider position appears to be set like so:

opt = QtGui.QStyleOptionSlider()
opt.sliderPosition = value

This appears to be the reason for the failure because value is a float and implicit conversion fails in Python 3.10.

Python 3.9

Python 3.9.10 (main, Mar  2 2022, 14:03:08) 
[GCC 11.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from pyface.qt import QtGui
>>> QtGui.QStyleOptionSlider().sliderValue = 5
>>> QtGui.QStyleOptionSlider().sliderValue = 5.5
<stdin>:1: DeprecationWarning: an integer is required (got type float).  Implicit conversion to integers using __int__ is deprecated, and may be removed in a future version of Python.

Python 3.10

Python 3.10.2 (main, Jan 15 2022, 19:56:27) [GCC 11.1.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from pyface.qt import QtGui
>>> QtGui.QStyleOptionSlider().sliderValue = 5
>>> QtGui.QStyleOptionSlider().sliderValue = 5.5
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'float' object cannot be interpreted as an integer

[corranwebster]

This is a traitsui issue - there's nothing that the Pyface code can do to fix this.

[corranwebster]

Thanks for the comprehensive report!