[pygtk] Another sort problem

[Brad Schick]

In my ListStore custom sort function that sometime I was getting None
values after appending new rows to a model. Instead of resorting the
model after a complete row is inserted, it looks like ListStore is
resorting after each column of a new row is inserted.

Run the example below and click the Append button. You will see that
'sort_func' is called twice, the first time with a value of None in
the second column of the model. This can be guarded against, but that
pretty ugly (and most people would not know it was needed).

Maybe this is a gtk+ bug? I'm not on any gtk+ mailing lists yet, so
I'm starting here.

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#!/usr/bin/env python
import pygtk
pygtk.require('2.0')
import gtk

def sort_func( model, iter1, iter2 ):
    # If the next line is commented, the iterators become corrupted
    print "model len", len(model)
    print model.get_value(iter1, 1), model.get_value(iter2, 1)
    result = ord(model.get_value(iter1, 1)) - ord(model.get_value(iter2, 1))
    return min( max(result, -1), 1 ) #  keep results in range

def append_model( button = None ) :
    print "\n+++ append"
    model.append( ('z','z') )
    print "--- append\n"
    return True

model = gtk.ListStore( str, str )
model.set_sort_func( 1001, sort_func )
map( model.append, (('a','f'), ('g','e'), ('c','n'), ('d','p')) )
model.set_sort_column_id( 1001, gtk.SORT_ASCENDING )

tree = gtk.TreeView( model )
tree.set_reorderable( False )

render = gtk.CellRendererText()
col0 = gtk.TreeViewColumn( 'col0', render )
col0.add_attribute( render, "text", 0 )
col0.set_sort_column_id(0)

render = gtk.CellRendererText()
col1 = gtk.TreeViewColumn( 'col1', render )
col1.add_attribute( render, "text", 1 )
col1.set_sort_column_id(1001)

tree.append_column( col0 )
tree.append_column( col1 )
tree.set_headers_clickable( True )

window = gtk.Window( gtk.WINDOW_TOPLEVEL )
window.connect( "destroy", gtk.main_quit )

vbox = gtk.VBox( False, 0 )
window.add(vbox)

button = gtk.Button( "Append" )
button.connect( "clicked", append_model )

vbox.pack_start( button )
vbox.pack_start( tree )

window.show_all()
gtk.main()