Unresolvable Ruby Gtk2 Error

Question

I keep getting a 'uninitialize GLib::Object' error from my code.

Here's the code:

class MainWindow < Gtk::Window
    def initialize
        title = "I'm The Title Of An Application! Yay!"
        border_width = 10
        set_size_request(600, 300)

        signal_connect("destroy") { Gtk.main_quit }

        @vbox = Gtk::VBox.new(false, 10)

        add(@vbox)
        show_all
    end
end

main_window = MainWindow.new

With this, I get the error

in `set_size_request': uninitialize GLib::Object

So I move that tidbit of code to outside the class like so:

main_window = MainWindow.new
    main_window.set_size_request(600, 300)

Then I get:

in `signal_connect': uninitialize GLib::Object

So I change it so my class and move the 'signal_connect' method outside the class with 'set_resize_request', which looks like this:

main_window = MainWindow.new
    main_window.set_size_request(600, 300)
    main_window.signal_connect("destroy") { Gtk.main_quit }

And it gives me:

in `add': uninitialize GLib::Object

Gwar! I change it yet again...

main_window = MainWindow.new
    main_window.set_size_request(600, 300)
    main_window.signal_connect("destroy") { Gtk.main_quit }
    main_window.add(@vbox)

Now this?!

in `show_all': uninitialize GLib::Object

So, yet again, I remove the method from the class and put it outside of the class

main_window = MainWindow.new
    main_window.set_size_request(600, 300)
    main_window.signal_connect("destroy") { Gtk.main_quit }
    main_window.add(@vbox)
    main_window.show_all

Maybe... just maybe it'll work this time, so I hope for the best and run the code again...

in `set_size_request': uninitialize GLib::Object

What?! What's going on here?

Answer 1

I think you have to call super before anything else at the initialization phase:

def initialize
  super
  # Other code goes here
  # ...
end

Also don't forget to add Gtk.main :

main_window = MainWindow.new
# Don't forget this...
Gtk.main

Answer 2

In addition to khell's answer you should also note that your first two lines of initialize:

    title = "I'm The Title Of An Application! Yay!"
    border_width = 10

Create two local variables that are never used. You probably want to prepend self. there.