Question

I have a Python script which uses a glade file to define its UI, and has a lot of repetitive widgets, each one to adjust a different numerical attribute of a certain active object. Since it is repetitive, I decided to define all the handlers in a separate file for encapsulation and readability. Here are some code excerpts:

The main file:

import pygtk
pygtk.require('2.0')
import gtk, gobject, cairo, gtk.glade

from Handlers import Handlers
from FramesetParameters import FramesetParameters
from GeometricRules import GeometricRules
from BikeDrawing import BikeDrawing

p=FramesetParameters("fitting", "handling", "construction")

builder = gtk.Builder()
builder.add_from_file("FramesetDesignerUI.glade")
Handlers(p)
builder.connect_signals(Handlers.__dict__)

mainWindow = builder.get_object("mainWindow")    
mainWindow.show_all()
gtk.main()

The Handlers.py file:

class Handlers:
    def adjustbottomBracketHeight(widget):
        obj.bottomBracketHeight = widget.get_value()

    def adjustseatTubeAngle(widget):
        obj.seatTubeAngle = widget.get_value()

    def adjustseatTubeLength(widget):
        obj.seatTubeLength = widget.get_value()

    def adjusttopTubeLength(widget):
        obj.topTubeLength = widget.get_value()

    def adjustheadTubeAngle(widget):
        obj.headTubeAngle = widget.get_value()

    def adjustheadTubeTopHeight(widget):
        obj.headTubeTopHeight = widget.get_value()

    def adjustrearAxlePosition(widget):
        obj.rearAxlePosition = widget.get_value()

    def adjusttrail(widget):
        obj.trail = widget.get_value()

    def adjustseatTubeExtension(widget):
        obj.seatTubeExtension = widget.get_value()

    def adjustheadTubeUpperExtension(widget):
        obj.headTubeUpperExtension = widget.get_value()

    def adjustheadTubeLowerExtension(widget):
        obj.headTubeLowerExtension = widget.get_value()

    def adjustforkCrownBulk(widget):
        obj.forkCrownBulk = widget.get_value()

When I run the program, the GUI shows up properly, but when I move a slider I get this error:

Traceback (most recent call last):
  File "/home/helton/Dropbox/Profilez/00Computacional/00REFACTORY97/Handlers.py", line 6, in adjustseatTubeAngle
    obj.seatTubeAngle = widget.get_value()
NameError: global name 'obj' is not defined

I know a little about namespaces and scope, but I am very noob on Python and Object orienting in general, so I do not know exactely what I should do. Any help would be much appreciated.

Answer 1

I think you’ve forgotten the self argument all over the place.

i.e. change this:

class Handlers:
    def adjustbottomBracketHeight(widget):
        obj.bottomBracketHeight = widget.get_value()

to

class Handlers:
    def adjustbottomBracketHeight(obj, widget):
        obj.bottomBracketHeight = widget.get_value()