python gobject call freezes gui

Question

I am using python with gtk. I want to download a file, and while this is happening i draw an animated gif on the window. But everytime the download starts, the gif is freezing. I thought the gobject call should fix this, but seems not like.

The call is:

in the gui class

  ...
  gobject.timeout_add(3000, self.load)
  gtk.main()

and the load function:

 def load(self):
     ul = urllib2.open('http://xxxx/')
     data = ul.read()
     while gtk.events_pending():
          gtk.main_iteration()
     return True

with every call of load the gui stacks. Any way to do that better?

original code:

self.opener = urllib2.build_opener() 
self.opener.addheaders.append(('Cookie', self.cookie)) 
self.state = self.opener.open('http://'+gd_adress+'/state.cst?Lang=en')
self.state_data = self.state.read()

score 4 · Accepted Answer · edited May 23 '17 at 12:27

4

You need to use an asynchronous call that integrates with the GObject main loop.

Probably the easiest is to use GIO:

import gio

f = gio.File(uri='http://xxxx/')
def on_ready(gdaemonfile, result):
    data, length, tag = f.load_contents_finish(result)
f.load_contents_async(on_ready)

Jono Bacon has a great writeup: http://www.jonobacon.org/2010/03/15/download-files-async-with-gio-and-python/

Unfortunately GIO doesn't support setting HTTP cookies as far as I can tell. In that case the best option is probably to use threads and use GLib.idle_add to return data to the main loop, as in Webkit threads with PyGObject on Gtk3:

import threading
import glib
glib.threads_init()

def load_data():
    opener = urllib2.build_opener() 
    opener.addheaders.append(('Cookie', cookie)) 
    state = opener.open('http://'+gd_adress+'/state.cst?Lang=en')
    state_data = state.read()
    glib.idle_add(on_read_data, state_data)
thread = threading.Thread(target=load_data)
thread.start()

The idea is that this encapsulates the blocking call in a thread that returns data to the main thread when it is ready, so the rest of your code can ignore the fact that threads are being used.

edited May 23 '17 at 12:27

Community

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answered Aug 22 '12 at 11:31

ecatmur

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Yeah thats quite what i need. But i need to add a cookie information to the http header.. how to do this here? Here is the code i have really: – HappyHacking Aug 22 '12 at 11:50
if i try it like this i get an error: GLib.threads_init() NameError: name 'GLib' is not defined – HappyHacking Aug 22 '12 at 12:52
@user1508490 it might be `glib` lower case. Depending on the version you might have to use `gtk.threads_init` instead of `glib.threads_init` and/or `gobject.idle_add` instead of `glib.idle_add`. – ecatmur Aug 22 '12 at 12:59
yeah thanks a lot!! i got it 1 second befor you wrote me :) Now its working very awesome :) – HappyHacking Aug 22 '12 at 13:00

python gobject call freezes gui

1 Answers1