PyGtk - TreeView and selected row

Question

Hi, I have a TreeView and when I click in it, i receive the error:

Traceback (most recent call last):
  File "pyparty.py", line 76, in get_selected_user
    self.selected_user = tree_model.get_value(tree_iter, 0)
TypeError: iter must be a GtkTreeIter

It just happen for the first click. After that it works fine. I don't know what's wrong. Here's the code:

#! /usr/bin/python

import gtk
import pygtk
pygtk.require('2.0')
import os
import add_user
import user_commands_wrapper

class PyParty:
    def __init__(self):
        self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)
        self.window.set_title('PyParty')
        self.window.set_position(gtk.WIN_POS_CENTER)
        self.window.set_border_width(5)

        self.window.connect('delete_event', self.closeWindow)

        self.table = gtk.Table(5, 2, False)

        self.title_label = gtk.Label('Users')
        self.add_button = gtk.Button('Add')
        self.edit_button = gtk.Button('Edit')
        self.delete_button = gtk.Button('Delete')
        self.exit_button = gtk.Button('Exit')

        self.add_button.connect('clicked', self.addUser)

        self.tree_store = gtk.TreeStore(str, str)

        #Remover passagem de valores para o construtor
        for user in user_commands_wrapper.User('', '').get_all_users():
            self.tree_store.append(None, [user.pw_name, user.pw_gecos])

        self.tree_view = gtk.TreeView(self.tree_store)
        self.tree_view.connect('button_press_event', self.get_selected_user)

        self.username_tree_view_column = gtk.TreeViewColumn('username')
        self.realname_tree_view_column = gtk.TreeViewColumn('realname')

        self.tree_view.append_column(self.username_tree_view_column)
        self.tree_view.append_column(self.realname_tree_view_column)

        self.username_cell = gtk.CellRendererText()
        self.username_tree_view_column.pack_start(self.username_cell, True)
        self.username_tree_view_column.add_attribute(self.username_cell, 'text', 0)

        self.realname_cell = gtk.CellRendererText()
        self.realname_tree_view_column.pack_start(self.realname_cell, True)
        self.realname_tree_view_column.add_attribute(self.realname_cell, 'text', 1)

        self.table.attach(self.title_label, 0, 2, 0, 1)
        self.table.attach(self.tree_view, 0, 1, 1, 5)
        self.table.attach(self.add_button, 1, 2, 1, 2)
        self.table.attach(self.edit_button, 1, 2, 2, 3)
        self.table.attach(self.delete_button, 1, 2, 3, 4)
        self.table.attach(self.exit_button, 1, 2, 4, 5)

        self.window.add(self.table)

        self.window.show_all()
        gtk.main()

    # Callback methods
    def closeWindow(self, widget, data = None):
        print self.selected_user
        gtk.main_quit()

    def addUser(self, widget, data = None):
        add_user.AddUser()

    def get_selected_user(self, widget, data = None):
        selection = self.tree_view.get_selection()
        selection.set_mode(gtk.SELECTION_SINGLE)
        tree_model, tree_iter = selection.get_selected()
        self.selected_user = tree_model.get_value(tree_iter, 0)

if __name__ == '__main__':
    # Remover
    if os.getenv('USER') == 'root':
        PyParty()
    else:
        print 'Only root can run that!'

Sorry for my english. Thank you guys.

Answer 1

I was using the wrong signal. This is the right one:

self.tree_view.connect('cursor-changed', self.get_selected_user)

Thank you