Can't set parent using GTK in Python.TypeError: argument parent: Expected Gtk.Window, but got __main__.function

Question

I'm trying to make a GTK program that brings up other child windows, but I can't seem to get set_transient_for to work.

The window I'm having trouble with is called "about" for now. I am trying to set the window under __init__ as its parent, but when I try to use the "About" menu, I get:

TypeError: argument parent: Expected Gtk.Window, but got __main__.function

Here's how I made the window.

class App(Gtk.Window):
def __init__(self):
    ## Create window. ##
    Gtk.Window.__init__(self, title="Simple Updater")
    self.set_border_width(5)
    self.set_resizable(False)

I used uimanager to create some menus and packed them in a grid. Here's how I call my about window.

## Menu functions ##

def add_about_actions(self, action_group):
    action_group.add_actions([
    ("About", None, "About"), 
    ("About...", None, "About...", None, None, Windows.About)
    ])

I created another class for my child windows. Here's where I try to set the parent as window __init__.

class Windows(Gtk.Window):
    def About(self):
        about = Gtk.Window(title="About")
        about.set_border_width(10)
        about.set_resizable(False)
        about.set_transient_for(__init__)

I also tried:

about.set_transient_for(App.__init__)

And here's how I set up my GTK loop.

top = App()
top.connect("delete-event", Gtk.main_quit)
top.show_all()
Gtk.main()

I've tried to figure out what's going on for several hours now with no luck. Any help would be appreciated.

Answer 1

This is a duplicate question of: GtkDialog mapped without a transient parent

You need to pass the variable holding the main window object.