GtkWindow can only contain one widget at a time

Question

I am using this code to retrieve and display an image from the web:

class Display(object):

    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://image.url/image.jpg').read()

        pbuf = gtk.gdk.PixbufLoader()
        pbuf.write(response)
        pbuf.close()
        self.image.set_from_pixbuf(pbuf.get_pixbuf())

        self.window.add(self.image)
        self.image.show()
        self.window.show()

    def main(self):
        gtk.main()

    def destroy(self, widget, data=None):
        gtk.main_quit()

It works, however I now want to display a text/entry box underneath the image (to retrieve the text later on). I added the following under self.image.show():

self.entry = gtk.Entry()
self.window.add(self.entry)
self.entry.show()

However, it spits out this warning then I run it, and the entry box doesn't appear:

ee.py:31: GtkWarning: Attempting to add a widget with type GtkEntry to a GtkWindow, but as a GtkBin subclass a GtkWindow can only contain one widget at a time; it already contains a widget of type GtkImage self.window.add(self.entry)

Not sure why it won't let me place more than one widget, does anyone have a solution for this?

score 3 · Answer 1 · answered Jan 10 '13 at 18:43

3

Take a look into widget packing. Essentially you use window.add to add a special packaging container, which in turn contains the main widgets and/or additional containers.

sketch:

hbox = HBox()
window.add(hbox)
hbox.pack_start(widget1)
hbox.pack_start(widget2)
window.show_all()

answered Jan 10 '13 at 18:43

Don Question

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Add window = Gtk.Window() at top. This worked great. – Ken H Apr 05 '23 at 23:56

score 3 · Accepted Answer · answered Jan 10 '13 at 18:46

Indeed packing is the answer.

import gtk
import urllib2
class Display(object):

    def __init__(self):
        self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)
        self.window.connect('destroy', self.destroy)
        self.window.set_border_width(10)

        # a box underneath would be added every time you do 
        # vbox.pack_start(new_widget)

        vbox = gtk.VBox()
        self.image = gtk.Image()
        response = urllib2.urlopen('http://1.bp.blogspot.com/-e-rzcjuCpk8/T3H-mSry7PI/AAAAAAAAOrc/Z3XrqSQNrSA/s1600/rubberDuck.jpg').read()

        pbuf = gtk.gdk.PixbufLoader()
        pbuf.write(response)
        pbuf.close()
        self.image.set_from_pixbuf(pbuf.get_pixbuf())

        self.window.add(vbox)
        vbox.pack_start(self.image, False)
        self.entry = gtk.Entry()
        vbox.pack_start(self.entry, False)

        self.image.show()
        self.window.show_all()

    def main(self):
        gtk.main()

    def destroy(self, widget, data=None):
        gtk.main_quit()

a=Display()
a.main()

score 0 · Answer 3 · answered Jul 31 '13 at 22:31

A GTK Window can only contain one child. If you want to add multiple widgets then you need a layout container such as a box or a grid to hold them. Boxes are fine in GTK2 but in GTK3 the developers advise switching to grids as boxes are now deprecated in GTK3.

GtkWindow can only contain one widget at a time

3 Answers3

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