PySide edit widget from another class

Question

I'm having trouble with a program that I'm writing. As its going to be quite large, I want to separate the layouts and signals, etc into separate classes/modules to make things easier to read. I would like to be able to edit the layout widgets from another class. Is this possible, or am I trying to do something that is not possible? I've included an example below, in case my explanation is not clear

class Layout:
  def __init__(self):
    self.callback = CallBack()

  def Gui(self):
    ''' 
    some layout with a listwidget that affects another listwidget depending on choice for example
    '''
    self.list1 = QtGui.QListWidget()
    self.list1.addItems(['chocolate', 'candy', 'pop'])

    self.list1.itemClicked.connect(self.callback.ButtonCallback)

    self.list2 = QtGui.QListWidget()

class CallBack(Layout):
  def __init__(self)
    super(CallBack, self).__init__()

  def ButtonCallback(self, button_signal):
    '''
    do get options for self.list2 depending on chosen item
    '''

    new_items = ['item1', 'item2', 'item3']
    Layout.list2.addItems(new_items)

I realize that the last line of the code is probably wrong but that is the part that I'm struggling with.

Many thanks for any help.

Answer 1

You can certainly have other objects answer your signals for you as long as they conform to QObject. In the example code that you have written, I would create the CallBack object as a subclass of QObject and retain a relationship to the Layout that owns it so that it can access the Layout object's attributes.

class Layout:
    def __init__(self):
        self.callback = CallBack(self)

    def Gui(self):
    ''' 
    some layout with a listwidget that affects another listwidget depending on choice for example
    '''
    self.list1 = QtGui.QListWidget()
    self.list1.addItems(['chocolate', 'candy', 'pop'])

    self.list1.itemClicked.connect(self.callback.ButtonCallback)

    self.list2 = QtGui.QListWidget()

class CallBack(QtCore.QObject):
    def __init__(self, parent)
        super(CallBack, self).__init__()
        self.parent = parent

    def ButtonCallback(self, button_signal):
    '''
    do get options for self.parent.list2 depending on chosen item
    '''

    new_items = ['item1', 'item2', 'item3']
    self.parent.list2.addItems(new_items)