def createMainWidget(argv):
    """
    Function to create the main widget.
    
    @param argv list of commandline parameters (list of strings)
    @return reference to the main widget (QWidget)
    """
    from HexEdit.HexEditMainWindow import HexEditMainWindow
    try:
        fileName = argv[1]
    except IndexError:
        fileName = ''
    editor = HexEditMainWindow(fileName, None)
    return editor
