QtRangeSlider's QLabeledDoubleRangeSlider Not Working With Negative Values - pyqt5

Question

Objective: To have a slider that:
Has (2) slider handles
Can accept int and float values when defining the slider domain
Can step in non-integer increments
Can be defined over a domain having negative values
Attempt: The code I've tried is below. Further, I was able to find a package qtrangeslider, pip install qtrangeslider. The package nearly covers all of my objectives.
Problem: The package qtrangeslider falls short when handling domains having negative values. The package is unable to accurately catch mouse clicks on the slider handles when dealing with a domain covering negative values.
Question: Would any one be skilled enough to track down why the package is failing and/or suggest a different package that meets my stated objectives.
'''
''' Begin : Import source dependencies '''
from PyQt5.QtWidgets import QApplication
from PyQt5 import QtCore, QtGui, QtWidgets
from qtrangeslider import QLabeledDoubleRangeSlider
''' End : Import source dependencies '''
''' Begin : Class definition of double handle slider '''
class AppDoubleRangeSlider( QtWidgets.QWidget ):
# Set the default style sheet definition
defaultStyleSpec = """
QSlider {
min-height: 10px;
}
QSlider::groove:horizontal {
border: 3px;
background: qradialgradient(cx:0, cy:0, radius: 1.2, fx:0.5, fy:0.5, stop:0 #B0C4DE, stop:1 #808080);
height: 20px;
margin: 15px 0;
border-radius: 10px;
}
QSlider::handle {
background: qradialgradient(cx:0, cy:0, radius: 1.2, fx:0.5, fy:0.5, stop:0 #00BFFF, stop:1 #1E90FF);
height: 20px;
width: 20px;
border-radius: 10px;
}
/*
"QSlider::sub-page" is the one exception ...
(it styles the area to the left of the QSlider handle)
*/
QSlider::sub-page:horizontal {
background: #32CD32;
border-top-left-radius: 10px;
border-bottom-left-radius: 10px;
}
/*
for QRangeSlider: use "qproperty-barColor". "sub-page" will not work.
*/
QSlider {
qproperty-barColor: #32CD32;
}
"""
''' Begin : Class constructor '''
def __init__(self, parent=None, minSliderVal=0.0, maxSliderVal=1.0, handleLeftValue=0.0, handleRightValue=1.0):
# Call the parent constructor
super( AppDoubleRangeSlider, self ).__init__( parent )
# Track the inputs
self.minSliderVal = minSliderVal
self.maxSliderVal = maxSliderVal
self.handleLeftValue = handleLeftValue
self.handleRightValue = handleRightValue
# Initialize class member defaults
self.initClassDefaults()
# Set window properties
self.initWindowProperties()
# Initialize the application layout space
self.initLayoutSpace()
# Initialize the widgets
self.initWidgets()
# Finalize layout settings
self.finalizeLayout()
''' End : Constructor '''
''' Begin : Method to set window properties '''
def initClassDefaults(self):
# Initialize a double handed slider with input parameters
self.appSlider = QLabeledDoubleRangeSlider( QtCore.Qt.Horizontal )
self.appSlider.setStyleSheet( self.defaultStyleSpec )
self.appSlider.setRange( self.minSliderVal, self.maxSliderVal )
self.appSlider.setMinimum( self.minSliderVal )
self.appSlider.setMaximum( self.maxSliderVal )
self.appSlider.setValue( (self.handleLeftValue, self.handleRightValue) )
# Connect the slider to a callback to handle value changes
self.appSlider.valueChanged.connect( self.callbackValueChange )
''' End : Method to set window properties '''
''' Begin : Method to return slider handle values '''
def getSliderValues(self):
print((self.handleLeftValue, self.handleRightValue),'\n\n')
# Return the slider's handle values
return (self.handleLeftValue, self.handleRightValue)
''' End : Method to return slider handle values '''
''' Begin : Method to respond to value changes '''
def callbackValueChange(self, value):
print((self.handleLeftValue, self.handleRightValue),'\n\n')
# Track the slider's handle values
self.handleLeftValue = value[ 0 ]
self.handleRightValue = value[ 1 ]
''' End : Method to respond to value changes '''
''' Begin : Method to set window properties '''
def initWindowProperties(self):
# Define the minimum app size
self.minAppWidth = 300
self.minAppHeight = 100
# Set minimum size constraints on the window
self.setMinimumWidth( self.minAppWidth )
self.setMinimumHeight( self.minAppHeight )
# Set initial window size
self.resize( self.minAppWidth, self.minAppHeight )
''' End : Method to set window properties '''
''' Begin : Method to initialize the application layout space '''
def initLayoutSpace(self):
# Initialize a layout
self.layoutRoot = QtWidgets.QHBoxLayout()
''' End : Method to initialize the application layout space '''
''' Begin : Method to initialize the application layout space '''
def initWidgets(self):
pass
''' End : Method to initialize the application layout space '''
''' Begin : Method to finalize layout settings '''
def finalizeLayout(self):
# Push the slider to the layout
self.layoutRoot.addWidget( self.appSlider )
# Finalize window layout
self.setLayout( self.layoutRoot )
''' End : Method to finalize layout settings '''
''' End : Class definition of double handle slider '''
from qtrangeslider import QDoubleRangeSlider
from PyQt5 import QtCore, QtGui, QtWidgets
app = QApplication( [ ] )
myApp = AppDoubleRangeSlider( minSliderVal=-1, maxSliderVal=1, handleLeftValue=-0.5, handleRightValue=0.5 )
myApp.show()
app.exec_()
'''