Unintuitive behavior of RangeEditor when mode is explicitly set

[pbrod]

Currently the actual range editor used in a "View" do not always conform to the one specified with the mode option, which is unintuitive.
For example if the range is given by low=0 and high=None the actual range editor used is always RangeTextEditor no matter if you specified mode='xslider' or mode='spinner'. That is unexpected. I would expect that explicit set mode would take precedence over automatic settings.

The lines controlling this behavior is given below in _get_simple_editor_class and _get_custom_editor_class methods:

traitsui/traitsui/editors/range_editor.py

Lines 214 to 245 in 87dceb2

	def _get_simple_editor_class(self):
	"""Returns the editor class to use for a simple style.
	The type of editor depends on the type and extent of the range being
	edited:
	* One end of range is unspecified: RangeTextEditor
	* **mode** is specified and not 'auto': editor corresponding to
	**mode**
	* Floating point range with extent > 100: LargeRangeSliderEditor
	* Integer range or floating point range with extent <= 100:
	SimpleSliderEditor
	* All other cases: SimpleSpinEditor
	"""
	low, high, is_float = self._low_value, self._high_value, self.is_float
	if (low is None) or (high is None):
	return toolkit_object("range_editor:RangeTextEditor")
	if (not is_float) and (abs(high - low) > 1000000000):
	return toolkit_object("range_editor:RangeTextEditor")
	if self.mode != "auto":
	return toolkit_object("range_editor:SimpleEditorMap")[self.mode]
	if is_float and (abs(high - low) > 100):
	return toolkit_object("range_editor:LargeRangeSliderEditor")
	if is_float or (abs(high - low) <= 100):
	return toolkit_object("range_editor:SimpleSliderEditor")
	return toolkit_object("range_editor:SimpleSpinEditor")

traitsui/traitsui/editors/range_editor.py

Lines 247 to 271 in 87dceb2

	def _get_custom_editor_class(self):
	"""Creates a custom style of range editor
	The type of editor depends on the type and extent of the range being
	edited:
	* One end of range is unspecified: RangeTextEditor
	* **mode** is specified and not 'auto': editor corresponding to
	**mode**
	* Floating point range: Same as "simple" style
	* Integer range with extent > 15: Same as "simple" style
	* Integer range with extent <= 15: CustomEnumEditor
	"""
	low, high, is_float = self._low_value, self._high_value, self.is_float
	if (low is None) or (high is None):
	return toolkit_object("range_editor:RangeTextEditor")
	if self.mode != "auto":
	return toolkit_object("range_editor:CustomEditorMap")[self.mode]
	if is_float or (abs(high - low) > 15):
	return self.simple_editor_class
	return toolkit_object("range_editor:CustomEnumEditor")