Using QSliders with model/view programming in PyQt

[bitrex]

I'm working on an application where I have a bunch of QSliders that I'd like to have update a model when they are changed. Similarly, I'd like the values of the sliders to update whenever the model is changed. I have been attempting to use the QDataWidgetMapper and QItemDelegate classes to accomplish this, but without much success.

Here is my model class:

@class dataModel(QtCore.QAbstractListModel):

def __init__(self, initData, parent=None):
    super(dataModel, self).__init__(parent)
    self.__data = initData
    
def data(self, index, role=QtCore.Qt.DisplayRole):
    if not index.isValid():
        return None

    if index.row() > len(self.__data):
        return None

    if role == QtCore.Qt.DisplayRole or role == QtCore.Qt.EditRole:
        return self.__data[index.row()]

    return None

def rowCount(self, parent=QtCore.QModelIndex()):
    return len(self.__data)

def setData(self, index, value, role=QtCore.Qt.EditRole):
    if not index.isValid() or role != QtCore.Qt.EditRole:
        return False
    
    self.__data[index.row()] = value
    self.dataChanged.emit(index, index)
    return True@

Here is the delegate class:

@class sliderDelegate(QtGui.QItemDelegate):
'''
classdocs
'''
def init(self, parent=None):
'''
Constructor
'''
super(sliderDelegate, self).init(parent)

def setEditorData(self, editor, index):
    editor.setValue(index.model().data(index, QtCore.Qt.EditRole))

def setModelData(self, editor, model, index):
    model.setData(index, editor.value(), QtCore.Qt.EditRole)@

And here is the setup code:

@ self._model = dataModel([])
self._parameterMapper = QtGui.QDataWidgetMapper(mainWindowInstance)
self._parameterMapper.setModel(self._model)
self._parameterMapper.setItemDelegate(sliderDelegate(mainWindowInstance))
self._parameterMapper.addMapping(self._mainWindowInstance.ui.mySlider, 0)
self._parameterMapper.toFirst()@

Unfortuantely, I get the following error when toFirst is called:

@ editor.setValue(index.model().data(index, QtCore.Qt.EditRole))
AttributeError: 'NoneType' object has no attribute 'data'@

How can I get this to work correctly? Thanks for any help.