maemo.org - Talk - View Single Post - Home plugin in python, threads and urlopen? Help

azrasta	2008-11-01 , 18:50
Posts: 6 \| Thanked: 4 times \| Joined on Oct 2008	#1

Hi guys, I think this is my first post on internettablettalk. I hope you can help me with a development issue I'm having.

I'm developing a home applet in python for the n810, (using notepad on windows and testing on the tablet). I don't have access to a scratchbox installation.

It's a slideshow plugin that grabs a photo list (xml) from a site, and then retrieves the photos from flickr.

I managed to make everything work, but as i'm using urllib, it freezes the ui until it's done retrieving the xml and the files.

So, I'm trying to use threads instead, and that's were everything falls apart. If I call urllib.urlopen from within a thread, it just doesn't work, no error, no freezing, nothing, it just stops working. The main thread continues as normal, but the thread stops when urlopen is called.

If I call urlopen from anywhere else in the main thread, it works fine.
If I remove urlopen from the thread code, it works fine (though obviously I can't retrieve the xml, so it's useless.

If I run the plugin code from the commandline, it all works (creates the thread, receives the xml file).
If I change the code to use gtk.Window instead of hildondesktop.HomeItem, it runs fine in the tablet and in windows.

So, the thread stopping at urlopen happens only when the code runs as a normal home plugin.

Here's a simplified version of the code. The problem is at _startthread (it outputs "in thread" to a gtk label, but "done thread" never appears).

Code:

import gtk
import hildondesktop
import os
import gobject

import threading,thread

gtk.gdk.threads_init()

import urllib

FB_URL = 'http://somesite.com/getphotolist.php'

class FbSlideshow(hildondesktop.HomeItem):
	def __init__(self):
		hildondesktop.HomeItem.__init__(self)
		#here i do other things like creating the UI, adding a label, etc
		self.do_get_poto()
	def do_get_photo(self):
		self.set_label( 'start thread')
		threading.Thread(target=self._startthread).start()
	def _startthread(self):
		self.set_label('in thread')
		url = FB_URL
		f=urllib.urlopen(url)
		self.set_label('done thread')
def hd_plugin_get_objects():
		plugin=FbSlideshow()
		return [plugin]

Do you have any idea of why is this happening? Is there another method I can use to retrieve the file without freezing the ui?

I'd really appreciate your help, I spent all day yesterday trying to find a solution, but got nothing.

Last edited by azrasta; 2008-11-01 at 22:02.

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