Use Gtk.events_pending to show a loading GtkTreevi

Question

I can't find a good simple tutorial on how to show the progress of a Gtk.TreeView loading data. This should be done with Gtk.events_pending(), as far as I can tell.

Answer 1

Here is a MCVE for reference:

#!/usr/bin/env python

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk, GLib
import os, sys


class GUI (Gtk.Window):
    def __init__(self):

        Gtk.Window.__init__(self, title = "events_pending example")
        box = Gtk.Box(orientation = Gtk.Orientation.VERTICAL)
        self.add(box)
        sw = Gtk.ScrolledWindow()
        box.pack_start(sw, True, True, 0)
        p_bar = Gtk.ProgressBar()
        box.pack_start(p_bar, False, False, 0)
        model = Gtk.ListStore(int)
        view = Gtk.TreeView(model = model)
        sw.add(view)
        renderer = Gtk.CellRendererText()
        column = Gtk.TreeViewColumn("Numbers", renderer, text=0)
        view.append_column(column)
        self.show_all()
        self.set_size_request(300, 300)
        self.connect("destroy", self.on_window_destroy)
        GLib.timeout_add(1000, self.add_numbers, model, p_bar)

    def add_numbers (self, treemodel, p_bar):
        for i in range(10000):
            treemodel.append([i])
            if i != 0: #do not divide by zero
                i = float(i) # convert variable to float first!
                p_bar.set_fraction(i/9999) 
            while Gtk.events_pending():
                Gtk.main_iteration()

    def on_window_destroy(self, window):
        Gtk.main_quit()

def main():
    app = GUI()
    Gtk.main()

if __name__ == "__main__":
    sys.exit(main())