Develop Reference

PyGTK, Threads and WebKit

In my PyGTK app, on button click I need to:
Fetch some html (can take some time)
Show it in new window
While fetching html, I want to keep GUI responsive, so I decided to do it in separate thread. I use WebKit to render html.
The problem is I get empty page in WebView when it is in separated thread.
This works:
import gtk
import webkit
webView = webkit.WebView()
webView.load_html_string('<h1>Hello Mars</h1>', 'file:///')
window = gtk.Window()
window.add(webView)
window.show_all()
gtk.mainloop()
This does not work, produces empty window:
import gtk
import webkit
import threading
def show_html():
webView = webkit.WebView()
webView.load_html_string('<h1>Hello Mars</h1>', 'file:///')
window = gtk.Window()
window.add(webView)
window.show_all()
thread = threading.Thread(target=show_html)
thread.setDaemon(True)
thread.start()
gtk.mainloop()
Is it because webkit is not thread-safe. Is there any workaround for this?

According to my experience, one of the things that sometimes doesn't work as you expect with gtk is the update of widgets in separate threads.
To workaround this problem, you can work with the data in threads, and use glib.idle_add to schedule the update of the widget in the main thread once the data has been processed.
The following code is an updated version of your example that works for me (the time.sleep is used to simulate the delay in getting the html in a real scenario):
import gtk, glib
import webkit
import threading
import time
# Use threads
gtk.gdk.threads_init()
class App(object):
def __init__(self):
window = gtk.Window()
webView = webkit.WebView()
window.add(webView)
window.show_all()
self.window = window
self.webView = webView
def run(self):
gtk.main()
def show_html(self):
# Get your html string
time.sleep(3)
html_str = '<h1>Hello Mars</h1>'
# Update widget in main thread
glib.idle_add(self.webView.load_html_string,
html_str, 'file:///')
app = App()
thread = threading.Thread(target=app.show_html)
thread.start()
app.run()
gtk.main()

I don't know anything about webkit inner workings, but maybe you can try it with multiple processes.

Why does this pygtk TextView refuse to wrap?

I have a textview inside a scrolledwindow that refuses to wrap to words/chars/wordschars no matter how I set the wrap mode. It simply extends the size of itself and its containers as it pleases. Here's an example:
import gtk
window = gtk.Window(gtk.WINDOW_TOPLEVEL)
window.set_default_size(256,256)
scroll = gtk.ScrolledWindow()
scroll.set_policy(gtk.POLICY_NEVER, gtk.POLICY_ALWAYS)
view = gtk.TextView()
view.set_wrap_mode(gtk.WRAP_CHAR)
scroll.add(view)
window.add(scroll)
window.show_all()
gtk.main()
How can I make it wrap? If it matters, I need the parent window to be resizeable by the user, just not the text.

You need to set the size request on the TextView's container (which is scroll in your example), not the Window or the TextView itself.
Try the following:
import gtk
if __name__ == "__main__":
window = gtk.Window(gtk.WINDOW_TOPLEVEL)
scroll = gtk.ScrolledWindow()
scroll.set_policy(gtk.POLICY_NEVER, gtk.POLICY_ALWAYS)
view = gtk.TextView()
view.set_wrap_mode(gtk.WRAP_CHAR)
scroll.set_size_request(256, 256)
scroll.add(view)
window.add(scroll)
window.show_all()
gtk.main()

I just ran your code and word wrapping seems to be working fine. What are you running it on? I'm using PyGTK 2.22 on Ubuntu 11.04.

How to display an image next to a menu item?

I am trying to get an image to appear next to a menu item but it isn't working.
In order to make this as simple as possible, I have created a very simple example below that highlights the problem:
import pygtk
pygtk.require('2.0')
import gtk
class MenuExample:
def __init__(self):
window = gtk.Window()
window.set_size_request(200, 100)
window.connect("delete_event", lambda w,e: gtk.main_quit())
menu = gtk.Menu()
menu_item = gtk.ImageMenuItem("Refresh")
img = gtk.image_new_from_stock(gtk.STOCK_REFRESH, gtk.ICON_SIZE_MENU)
img.show()
menu_item.set_image(img)
menu.append(menu_item)
menu_item.show()
root_menu = gtk.MenuItem("File")
root_menu.show()
root_menu.set_submenu(menu)
vbox = gtk.VBox(False, 0)
window.add(vbox)
vbox.show()
menu_bar = gtk.MenuBar()
vbox.pack_start(menu_bar, False, False, 2)
menu_bar.show()
menu_bar.append(root_menu)
window.show()
def main():
gtk.main()
return 0
if __name__ == "__main__":
MenuExample()
main()
When I run the application, it shows the menu item, but it does not show the image next to it.
OS: Ubuntu 10.04 64-bit
Python version: 2.6.5

Hmmm... it turns out the answer was that my desktop theme had disabled icons for menus. (Who knows why.)
After enabling the option, the icons now show up.

How to display an image from web?

I have written this simple script in python:
import gtk
window = gtk.Window()
window.set_size_request(800, 700)
window.show()
gtk.main()
now I want to load in this window an image from web ( and not from my PC ) like this:
http://www.dailygalaxy.com/photos/uncategorized/2007/05/05/planet_x.jpg
How can I do that ?
P.S. I don't want download the image ! I just want load the image from the URL.

This downloads the image from a url, but writes the data into a gtk.gdk.Pixbuf instead of to a file:
import pygtk
pygtk.require('2.0')
import gtk
import urllib2
class MainWin:
def destroy(self, widget, data=None):
print "destroy signal occurred"
gtk.main_quit()
def __init__(self):
self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)
self.window.connect("destroy", self.destroy)
self.window.set_border_width(10)
self.image=gtk.Image()
response=urllib2.urlopen(
'http://www.dailygalaxy.com/photos/uncategorized/2007/05/05/planet_x.jpg')
loader=gtk.gdk.PixbufLoader()
loader.write(response.read())
loader.close()
self.image.set_from_pixbuf(loader.get_pixbuf())
# This does the same thing, but by saving to a file
# fname='/tmp/planet_x.jpg'
# with open(fname,'w') as f:
# f.write(response.read())
# self.image.set_from_file(fname)
self.window.add(self.image)
self.image.show()
self.window.show()
def main(self):
gtk.main()
if __name__ == "__main__":
MainWin().main()

Download the image. Google on how to download files with python, there are easy-to-use libraries for that.
Load the image into a widget. Look up how to display an image in GTK.
Sorry for the lack of detail, but the answer would get long and you'd still be better off reading on those subjects somewhere else.
Hope it helps!

Here's a simple script using WebKit:
#!/usr/bin/env python
import gtk
import webkit
window = gtk.Window()
window.set_size_request(800, 700)
webview = webkit.WebView()
window.add(webview)
window.show_all()
webview.load_uri('http://www.dailygalaxy.com/photos/uncategorized/2007/05/05/planet_x.jpg')
gtk.main()
Take note, though, that this does in fact download the image.

Need a simple "Hello World" example using the Webkit library in Python

Does anyone know of a simple "Hello World" example for using the Webkit library in Python? I have a GTK window, and inside I want to put Webkit.
With Python/mozembed (Mozilla/Gecko), this is simple:
mozembed = gtkmozembed.MozEmbed()
mozembed.load_url('http://google.com/')
..and I have already created my browser, how do I do this with WebKit?

Did you check the Python bindings for the WebKit GTK+ port. In one of the directory there are demos on how to use it, including a browser: python demos/tabbed_browser.py
You could check also the slides of a FOSDEM by Alp Toker on WebKit GTK+ (pdf) Developing hybrid Web/GTK+ rich internet applications.
import gtk
import webkit
view = webkit.WebView()
sw = gtk.ScrolledWindow()
sw.add(view)
win = gtk.Window(gtk.WINDOW_TOPLEVEL)
win.add(sw)
win.show_all()
view.open("http://w3.org/")
gtk.main()
That should give you good hints for starting.

Now with WebKitGtk2
import gi
gi.require_version('Gtk', '3.0')
gi.require_version('WebKit2', '4.0')
from gi.repository import Gtk, WebKit2
window = Gtk.Window()
window.set_default_size(800, 600)
window.connect("destroy", Gtk.main_quit)
scrolled_window = Gtk.ScrolledWindow()
webview = WebKit2.WebView()
webview.load_uri("https://google.cl")
scrolled_window.add(webview)
window.add(scrolled_window)
window.show_all()
Gtk.main()