diff -urp wallpapoz-0.6.2.py2/setup.py wallpapoz-0.6.2.py3/setup.py
--- wallpapoz-0.6.2.py2/setup.py	2019-09-02 14:04:36.124389528 +0900
+++ wallpapoz-0.6.2.py3/setup.py	2019-09-02 14:50:57.162142691 +0900
@@ -1,4 +1,4 @@
-#!/usr/bin/python2
+#!/usr/bin/python3
 # -*- coding: utf-8 -*-
 
 #=============================================================================
@@ -62,7 +62,7 @@ Options:
 """)
 
 def info():
-  print usage_info
+  print (usage_info)
   sys.exit(1)
 
 def install(src, dst):
@@ -73,9 +73,9 @@ def install(src, dst):
     if not os.path.isdir(os.path.dirname(dst)):
       os.makedirs(os.path.dirname(dst))
     shutil.copy2(src, dst)
-    print _("Installed"), dst
+    print (_("Installed"), dst)
   except:
-    print _("Error while installing"), dst
+    print (_("Error while installing"), dst)
 
 def uninstall(path):
   try:
@@ -86,71 +86,75 @@ def uninstall(path):
       shutil.rmtree(path)
     else:
       return
-    print _("Removed"), path
+    print (_("Removed"), path)
   except:
-    print _("Error while removing"), path
+    print (_("Error while removing"), path)
 
 def check_dependencies():
   required_found = True
   recommended_found = True
-  print _("Checking dependencies...")
+  print (_("Checking dependencies..."))
   print
-  print _("Required dependencies:")
+  print (_("Required dependencies:"))
   print
   # Should also check the PyGTK version. To do that we have to load the
   # gtk module though, which normally can't be done while using `sudo`.
   try:
-    import pygtk
-    print "    PyGTK ........................ OK"
+    #import pygtk
+    import gi
+    gi.require_version("Gtk", "3.0")
+    from gi.repository import Gtk
+    print ("    PyGTK ........................ OK")
   except ImportError:
-    print "    !!! PyGTK .................... ", _("Not found")
+    print ("    !!! PyGTK .................... ", _("Not found"))
     required_found = False
   try:
     # shutdown the warnings
     import warnings
     warnings.simplefilter("ignore", Warning)
-    import gtk.glade
-    print "    Python Glade ................. OK"
-  except ImportError:
-    print "    !!! Python Glade ............. ", _("Not found")
+    #import gtk.glade
+    Gtk.Builder()
+    print ("    Python Glade ................. OK")
+  except (ImportError, AttributeError):
+    print ("    !!! Python Glade ............. ", _("Not found"))
     required_found = False
   except RuntimeError:
     # so we can check dependency when there is no DISPLAY
     warnings.simplefilter("default", Warning)
     if not os.environ.get("DISPLAY"):
-      print "    Python Glade ................. SKIP"
+      print ("    Python Glade ................. SKIP")
     else:
-      print "    !!! Python Glade ............. ", _("Not found")
-      required_found = False
+      print ("    !!! Python Glade ............. ", _("Not found"))
+      #required_found = False
   try:
     from PIL import Image
-    print "    Python Imaging Library ....... OK"
+    print ("    Python Imaging Library ....... OK")
   except ImportError:
-    print "    !!! Python Imaging Library ... ", _("Not found")
+    print ("    !!! Python Imaging Library ... ", _("Not found"))
     required_found = False
   try:
     import gnome
-    print "    Gnome Python ................. OK"
+    print ("    Gnome Python ................. OK")
   except ImportError:
-    print "    !!! Gnome Python ............. ", _("Not found")
+    print ("    !!! Gnome Python ............. ", _("Not found"))
     recommended_found = False
   out = os.popen('which xwininfo').readlines
   if out == []:
-    print "    Xwininfo tool ................ ", _("Not found")
+    print ("    Xwininfo tool ................ ", _("Not found"))
     required_found = False
   else:
-    print "    Xwininfo tool ................ OK"
+    print ("    Xwininfo tool ................ OK")
 
   if not required_found:
     print
-    print _("Could not find all required dependencies!")
-    print _("Please install them and try again.")
+    print (_("Could not find all required dependencies!"))
+    print (_("Please install them and try again."))
     print
     sys.exit(1)
   if not recommended_found:
     print
-    print _("Gnome Python is not found. Wallpapoz still could be used and it has been installed.")
-    print _("But it means you can not access help documentation in your native language if it is available.")
+    print (_("Gnome Python is not found. Wallpapoz still could be used and it has been installed."))
+    print (_("But it means you can not access help documentation in your native language if it is available."))
     print
 
 install_dir = "/usr/local/"
@@ -166,12 +170,12 @@ for opt, value in opts:
   if opt == "--installdir":
     install_dir = value
     if not os.path.isdir(install_dir):
-      print _("\n*** Error:"), install_dir, _("does not exist.\n" )
+      print (_("\n*** Error:"), install_dir, _("does not exist.\n" ))
       info()
 
 if args == ["install"]:
   check_dependencies()
-  print _("Installing Wallpapoz in"), install_dir, "...\n"
+  print (_("Installing Wallpapoz in"), install_dir, "...\n")
   install("src/wallpapoz", "bin/wallpapoz")
   install("src/daemon_wallpapoz", "bin/daemon_wallpapoz")
   install("src/launcher_wallpapoz.sh", "bin/launcher_wallpapoz.sh")
@@ -193,7 +197,7 @@ if args == ["install"]:
       "share/gnome/help/wallpapoz/" + lang + "/legal.xml")
 
 elif args == ["uninstall"]:
-  print _("Uninstalling Wallpapoz from"), install_dir, "...\n"
+  print (_("Uninstalling Wallpapoz from"), install_dir, "...\n")
   uninstall("bin/wallpapoz")
   uninstall("bin/daemon_wallpapoz")
   uninstall("bin/launcher_wallpapoz.sh")
@@ -211,11 +215,11 @@ elif args == ["uninstall"]:
     uninstall("share/gnome/help/wallpapoz/" + lang + "/wallpapoz.xml")
     uninstall("share/gnome/help/wallpapoz/" + lang + "/legal.xml")
   print
-  print _("""
+  print (_("""
 There might still be files in ~/.wallpapoz/ left on your system.
 Please remove that directory manually if you do not plan to
 install Wallpapoz again later.
-""")
+"""))
 
 else:
   info()
diff -urp wallpapoz-0.6.2.py2/share/wallpapoz/lib/wallpapoz_system.py wallpapoz-0.6.2.py3/share/wallpapoz/lib/wallpapoz_system.py
--- wallpapoz-0.6.2.py2/share/wallpapoz/lib/wallpapoz_system.py	2019-09-02 14:04:36.105389275 +0900
+++ wallpapoz-0.6.2.py3/share/wallpapoz/lib/wallpapoz_system.py	2019-09-01 21:08:35.000000000 +0900
@@ -44,8 +44,8 @@ class WallpapozSystem:
 
     # Check if total_workspaces changed only here
     if WallpapozSystem.static_total_workspaces != self.total_workspaces:
-      print "daemon_wallpapoz: the number of total workspaces changed during initialization process."
-      print "daemon_wallpapoz: respawning daemon_wallpapoz."
+      print ("daemon_wallpapoz: the number of total workspaces changed during initialization process.")
+      print ("daemon_wallpapoz: respawning daemon_wallpapoz.")
       self.respawn_system()
 
   def exec_cmd_under_X(self, cmd):
@@ -57,32 +57,35 @@ class WallpapozSystem:
         shell = True
         )
     except OSError:
-      print "daemon_wallpapoz: fork failed for %s, exiting." %cmd
+      print ("daemon_wallpapoz: fork failed for %s, exiting." %cmd)
       sys.exit(1)
 
     pstdout = p.stdout.read()
     pstderr = p.stderr.read()
     ret = p.wait()
+    # FIXME
+    pstdout_str = pstdout.decode('utf-8')
 
     kill_daemon = False
 
     if (ret != 0) and (ret & 0xFF):
-        print "daemon_wallpapoz: %s returned status %i." %(cmd, ret)
-        print "daemon_wallpapoz: error message: %s" %pstderr
+        print ("daemon_wallpapoz: %s returned status %i." %(cmd, ret))
+        print ("daemon_wallpapoz: error message: %s" %pstderr)
         kill_daemon = True
 
-    if (cmd.find('xprop') >= 0) and (pstdout.find('no such atom') >= 0):
+    if (cmd.find('xprop') >= 0) and (pstdout_str.find('no such atom') >= 0):
         kill_daemon = True
-    if (cmd.find('xprop') >= 0) and (pstdout.find('not') >= 0):
+    if (cmd.find('xprop') >= 0) and (pstdout_str.find('not') >= 0):
         kill_daemon = True
 
     if kill_daemon:
         ## No X resource available, kill daemon_wallpapoz
-        print "daemon_wallpapoz: X resource seems no longer available."
-        print "daemon_wallpapoz: killing daemon_wallpapoz."
+        print ("daemon_wallpapoz: X resource seems no longer available.")
+        print ("daemon_wallpapoz: killing daemon_wallpapoz.")
         sys.exit(1)
 
-    return pstdout
+    #FIXME
+    return pstdout_str
 
   def set_style(self, style):
     self.wallpaper_style = style
@@ -209,7 +212,7 @@ class WallpapozSystem:
     new_argv = []
     new_argv.extend(sys.argv)
     os.execvp('daemon_wallpapoz', new_argv)
-    print "os.execvp failed, exiting..."
+    print ("os.execvp failed, exiting...")
     sys.exit(1)
 
   def prevent_multiple_start(self):
diff -urp wallpapoz-0.6.2.py2/share/wallpapoz/lib/xml_processing.py wallpapoz-0.6.2.py3/share/wallpapoz/lib/xml_processing.py
--- wallpapoz-0.6.2.py2/share/wallpapoz/lib/xml_processing.py	2012-02-20 03:57:12.000000000 +0900
+++ wallpapoz-0.6.2.py3/share/wallpapoz/lib/xml_processing.py	2019-09-01 21:23:33.000000000 +0900
@@ -28,7 +28,9 @@ import xml
 import os
 import sys
 import gettext
-import gtk
+import gi
+gi.require_version("Gtk", "3.0")
+from gi.repository import Gtk, GObject
 from wallpapoz_system import WallpapozSystem
 
 # i18n
@@ -36,8 +38,8 @@ APP = "wallpapoz"
 DIR = "../../locale"
 gettext.bindtextdomain(APP, DIR)
 gettext.textdomain(APP)
-gtk.glade.bindtextdomain(APP, DIR)
-gtk.glade.textdomain(APP)
+#gtk.glade.bindtextdomain(APP, DIR)
+#gtk.glade.textdomain(APP)
 _ = gettext.gettext
 
 ## XMLProcessing -- class for processing wallpapoz xml file
@@ -64,7 +66,7 @@ class XMLProcessing:
     # if wallpapoz run for the first time ( no configuration file )
     # we make default list, for every workspace, we give one wallpaper that is our current wallpaper
     if not os.path.exists(self.config_file):
-      print _("No configuration file. Use default configuration.")
+      print (_("No configuration file. Use default configuration."))
       home = os.environ['HOME']
       if not os.path.exists(home + '/.wallpapoz'):
         os.makedirs(home + '/.wallpapoz')
@@ -75,7 +77,7 @@ class XMLProcessing:
     try:
       self.xmldoc = minidom.parse(self.config_file)
     except xml.parsers.expat.ExpatError:
-      print _("The configuration file is corrupted. Remove it then create a new one again with Wallpapoz!")
+      print (_("The configuration file is corrupted. Remove it then create a new one again with Wallpapoz!"))
       sys.exit()
 
     # wallpapoz node
@@ -101,7 +103,7 @@ class XMLProcessing:
     try:
       self.xmldoc = minidom.parse(self.config_file)
     except xml.parsers.expat.ExpatError:
-      print _("The configuration file is corrupted. Remove it then create a new one again with Wallpapoz!")
+      print (_("The configuration file is corrupted. Remove it then create a new one again with Wallpapoz!"))
       sys.exit()
 
     # wallpapoz node
@@ -287,7 +289,7 @@ class XMLProcessing:
   # save the xml file
   def save(self):
     xml_file = open(self.config_file, "w")
-    xml_file.write( self.xmldoc.toxml("utf-8") )
+    xml_file.write( self.xmldoc.toxml("utf-8").decode("utf-8") )
 
   # fill list with default value
   def default_fill_list(self, type):
@@ -406,4 +408,4 @@ class XMLProcessing:
 
     # create it
     xml_file = open(self.config_file, "w")
-    xml_file.write( newdoc.toxml("utf-8") )
+    xml_file.write( newdoc.toxml("utf-8").decode("utf-8") )
diff -urp wallpapoz-0.6.2.py2/src/daemon_wallpapoz wallpapoz-0.6.2.py3/src/daemon_wallpapoz
--- wallpapoz-0.6.2.py2/src/daemon_wallpapoz	2019-09-02 14:04:36.168390114 +0900
+++ wallpapoz-0.6.2.py3/src/daemon_wallpapoz	2019-09-01 20:59:43.000000000 +0900
@@ -1,4 +1,4 @@
-#!/usr/bin/python2
+#!/usr/bin/python3
 # -*- coding: utf-8 -*-
 
 #================================================
@@ -33,7 +33,7 @@ import array
 import time
 import threading
 import random
-import gtk.glade
+#import gtk.glade
 import string
 
 # so we can call from anywhere
@@ -133,7 +133,7 @@ if __name__ == "__main__":
     total_workspaces = wallpapoz_system.get_total_workspaces()
 
     # create the index for wallpaper list thread
-    number.fromlist( range( total_workspaces ) )
+    number.fromlist( list(range( total_workspaces ) ) )
 
     # previous workspace
     previous_desktop = -1
diff -urp wallpapoz-0.6.2.py2/src/wallpapoz wallpapoz-0.6.2.py3/src/wallpapoz
--- wallpapoz-0.6.2.py2/src/wallpapoz	2019-09-02 14:04:36.159389994 +0900
+++ wallpapoz-0.6.2.py3/src/wallpapoz	2019-09-02 14:13:50.533772653 +0900
@@ -1,4 +1,4 @@
-#!/usr/bin/python2
+#!/usr/bin/python3
 # -*- coding: utf-8 -*-
 
 #=============================================================================
@@ -27,10 +27,10 @@
 ## wallpapoz.py -- the gui tool for creating configuration file and
 # calling daemon program
 
-import pygtk
-pygtk.require('2.0')
-import gtk.glade
-import gobject
+import gi
+gi.require_version("Gtk", "3.0")
+from gi.repository import Gtk as gtk, GObject as gobject, Gdk as gdk
+from gi.repository import GdkPixbuf
 import os
 import sys
 import stat
@@ -55,8 +55,8 @@ APP = "wallpapoz"
 DIR = "../share/locale"
 gettext.bindtextdomain(APP, DIR)
 gettext.textdomain(APP)
-gtk.glade.bindtextdomain(APP, DIR)
-gtk.glade.textdomain(APP)
+#gtk.glade.bindtextdomain(APP, DIR)
+#gtk.glade.textdomain(APP)
 _ = gettext.gettext
 
 # main class for the gui. This gui will contruct the configuration file that will be used by daemon
@@ -69,25 +69,32 @@ class Wallpapoz:
   # the contructor
   def __init__(self):
     # wallpapoz glade file
-    self.wallpapoz_glade_file = "../share/wallpapoz/glade/wallpapoz.glade"
+    #self.wallpapoz_glade_file = "../share/wallpapoz/glade/wallpapoz.glade"
+    self.wallpapoz_builder_file = "../share/wallpapoz/glade/wallpapoz-builder-wallpapoz_window.glade"
 
     # call the xmlprocessing class to read it later on method related to treeview
     self.wallpapozxml = XMLProcessing()
 
     # Load the glade
-    self.main_window = gtk.glade.XML(self.wallpapoz_glade_file, "wallpapoz_window", APP)
+    self.builder = gtk.Builder()
+    self.builder.set_translation_domain(APP)
+    self.builder.add_from_file(self.wallpapoz_builder_file)
+    #self.main_window = gtk.glade.XML(self.wallpapoz_glade_file, "wallpapoz_window", APP)
+    self.main_window = self.builder.get_object("wallpapoz_window")
 
     # window widget
-    self.main_window_widget = self.main_window.get_widget("wallpapoz_window")
+    self.main_window_widget = self.builder.get_object("wallpapoz_window")
 
     # treeview widget
-    self.treeview_widget = self.main_window.get_widget("treeview")
+    self.treeview_widget = self.builder.get_object("treeview")
+    # FIXME set here
+    self.treeselection = self.treeview_widget.get_selection()
 
     # image widget
-    self.image_widget = self.main_window.get_widget("wallpaper_image")
+    self.image_widget = self.builder.get_object("wallpaper_image")
 
     # image filename widget
-    self.wallpaper_filename = self.main_window.get_widget("wallpaper_name_label")
+    self.wallpaper_filename = self.builder.get_object("wallpaper_name_label")
 
     # create the pop up menu when we right click the treeview widget
     self.set_up_popup_menu()
@@ -121,7 +128,7 @@ class Wallpapoz:
             "on_move_up_activate" : self.move_up_node,
             "on_move_down_activate" : self.move_down_node,
             "on_treeview_button_press_event" : self.right_click_menu }
-    self.main_window.signal_autoconnect(dic)
+    self.builder.connect_signals(dic)
 
     # show treeview
     self.load_treeview()
@@ -132,16 +139,16 @@ class Wallpapoz:
   # set up popup menu when we right click the treeview widget
   def set_up_popup_menu(self):
     self.popup_menu = gtk.Menu()
-    add_wallpapers_files_menu = gtk.MenuItem(_("Add Wallpapers (Files)"))
-    add_wallpapers_directory_menu = gtk.MenuItem(_("Add Wallpapers (Directory)"))
-    self.cut_menu = gtk.MenuItem(_("Cut"))
-    self.copy_menu = gtk.MenuItem(_("Copy"))
-    paste_menu = gtk.MenuItem(_("Paste"))
-    self.rename_workspace_menu = gtk.MenuItem(_("Rename Workspace"))
-    self.change_wallpaper_menu = gtk.MenuItem(_("Change Wallpaper"))
-    self.delete_wallpapers_menu = gtk.MenuItem(_("Delete Wallpapers"))
-    move_up_menu = gtk.MenuItem(_("Move Up"))
-    move_down_menu = gtk.MenuItem(_("Move Down"))
+    add_wallpapers_files_menu = gtk.MenuItem(label=_("Add Wallpapers (Files)"))
+    add_wallpapers_directory_menu = gtk.MenuItem(label=_("Add Wallpapers (Directory)"))
+    self.cut_menu = gtk.MenuItem(label=_("Cut"))
+    self.copy_menu = gtk.MenuItem(label=_("Copy"))
+    paste_menu = gtk.MenuItem(label=_("Paste"))
+    self.rename_workspace_menu = gtk.MenuItem(label=_("Rename Workspace"))
+    self.change_wallpaper_menu = gtk.MenuItem(label=_("Change Wallpaper"))
+    self.delete_wallpapers_menu = gtk.MenuItem(label=_("Delete Wallpapers"))
+    move_up_menu = gtk.MenuItem(label=_("Move Up"))
+    move_down_menu = gtk.MenuItem(label=_("Move Down"))
     add_wallpapers_files_menu.connect("activate", self.add_wallpapers_files)
     add_wallpapers_directory_menu.connect("activate", self.add_wallpapers_directory)
     self.cut_menu.connect("activate", self.cut_treenode)
@@ -175,8 +182,8 @@ class Wallpapoz:
 
   # popup menu when user right-click the treeview widget
   def right_click_menu(self, widget, event):
-    if event.type == gtk.gdk.BUTTON_PRESS and event.button == 3:
-      self.popup_menu.popup(None, None, None, event.button, event.time)
+    if event.type == gdk.EventType.BUTTON_PRESS and event.button == 3:
+      self.popup_menu.popup(None, None, None, None, event.button, event.time)
 
   def restart_daemon(self, widget):
     self.stop_daemon(None)
@@ -201,8 +208,12 @@ class Wallpapoz:
 
   # when user click about menu item, show about dialog
   def display_about(self, widget):
-    about_dialog = gtk.glade.XML(self.wallpapoz_glade_file, "wallpapoz_about_dialog", APP)
-    aboutdlg_widget = about_dialog.get_widget("wallpapoz_about_dialog")
+    #about_dialog = gtk.glade.XML(self.wallpapoz_glade_file, "wallpapoz_about_dialog", APP)
+    self.about_dialog_builder_file = "../share/wallpapoz/glade/wallpapoz-builder-wallpapoz_about_dialog.glade"
+    self.about_dialog_builder = gtk.Builder()
+    self.about_dialog_builder.set_translation_domain(APP)
+    self.about_dialog_builder.add_from_file(self.about_dialog_builder_file)
+    aboutdlg_widget = self.about_dialog_builder.get_object("wallpapoz_about_dialog")
     aboutdlg_widget.connect('response', lambda w, e: aboutdlg_widget.destroy())
 
   # get the selection iter
@@ -326,15 +337,17 @@ class Wallpapoz:
       dialog_title = _("Choose Wallpapers")
 
     # our filechooser dialog
-    filechooser_dialog = gtk.FileChooserDialog(dialog_title, self.main_window_widget, gtk.FILE_CHOOSER_ACTION_OPEN)
+    filechooser_dialog = gtk.FileChooserDialog(dialog_title, self.main_window_widget, gtk.FileChooserAction.OPEN)
 
     # our button
-    cancel_button = filechooser_dialog.add_button(gtk.STOCK_CANCEL, gtk.RESPONSE_CANCEL)
+    cancel_button = filechooser_dialog.add_button(gtk.STOCK_CANCEL, gtk.ResponseType.CANCEL)
     if type_of_ok_button == "change":
-      ok_button = filechooser_dialog.add_button(_("Change"), gtk.RESPONSE_OK)
+      ok_button = filechooser_dialog.add_button(_("Change"), gtk.ResponseType.OK)
     elif type_of_ok_button == "add":
-      ok_button = filechooser_dialog.add_button(gtk.STOCK_OK, gtk.RESPONSE_OK)
-      gtk.Tooltips().set_tip(ok_button, _("Add wallpapers"))
+      ok_button = filechooser_dialog.add_button(gtk.STOCK_OK, gtk.ResponseType.OK)
+      # FIXME
+      #gtk.Tooltips().set_tip(ok_button, _("Add wallpapers"))
+      ok_button.set_tooltip_text(_("Add wallpapers"))
 
     # cancel will quit the filechooser dialog
     cancel_button.connect("clicked", lambda w: filechooser_dialog.destroy())
@@ -379,7 +392,7 @@ class Wallpapoz:
     filechooser_dialog.set_select_multiple(True)
 
     # if user choose the file, add his choice to treeview
-    if filechooser_dialog.run() == gtk.RESPONSE_OK:
+    if filechooser_dialog.run() == gtk.ResponseType.OK:
       # get the list of filename that we choose to add
       filenames = filechooser_dialog.get_filenames()
 
@@ -436,15 +449,21 @@ class Wallpapoz:
 
   # show up the preferences dialog
   def preferences_option(self, widget):
-    self.preferences_dialog = gtk.glade.XML(self.wallpapoz_glade_file, "preferences_dialog", APP)
-    preferences_dialog_widget = self.preferences_dialog.get_widget("preferences_dialog")
+    #self.preferences_dialog = gtk.glade.XML(self.wallpapoz_glade_file, "preferences_dialog", APP)
+    self.preferences_dialog_builder_file =  "../share/wallpapoz/glade/wallpapoz-builder-preferences_dialog.glade"
+    self.preferences_dialog_builder = gtk.Builder()
+    self.preferences_dialog_builder.set_translation_domain(APP)
+    self.preferences_dialog_builder.add_from_file(self.preferences_dialog_builder_file)
+    # FIXME
+    self.preferences_dialog = self.preferences_dialog_builder
+    preferences_dialog_widget = self.preferences_dialog.get_object("preferences_dialog")
 
     # input widgets
-    time_changed_widget = self.preferences_dialog.get_widget("preferences_dialog_spin_button_time")
-    random_order_widget = self.preferences_dialog.get_widget("preferences_dialog_show_wallpaper_random_order")
-    changing_workspace_widget = self.preferences_dialog.get_widget("preferences_dialog_change_wallpaper_changing_workspace")
-    style_widget = self.preferences_dialog.get_widget("preferences_dialog_style_combobox")
-    size_widget = self.preferences_dialog.get_widget("preferences_dialog_size_combobox")
+    time_changed_widget = self.preferences_dialog.get_object("preferences_dialog_spin_button_time")
+    random_order_widget = self.preferences_dialog.get_object("preferences_dialog_show_wallpaper_random_order")
+    changing_workspace_widget = self.preferences_dialog.get_object("preferences_dialog_change_wallpaper_changing_workspace")
+    style_widget = self.preferences_dialog.get_object("preferences_dialog_style_combobox")
+    size_widget = self.preferences_dialog.get_object("preferences_dialog_size_combobox")
 
     # load value from xml file
     time_changed_widget.set_value(float(self.wallpapozxml.delay()))
@@ -458,19 +477,19 @@ class Wallpapoz:
     changing_workspace_widget.set_active(self.wallpapozxml.change_wallpaper_when_changing_workspace())
 
     # button
-    cancel_button = self.preferences_dialog.get_widget("preferences_cancel_button")
+    cancel_button = self.preferences_dialog.get_object("preferences_cancel_button")
     cancel_button.connect("clicked", lambda w: preferences_dialog_widget.destroy())
 
-    ok_button = self.preferences_dialog.get_widget("preferences_ok_button")
+    ok_button = self.preferences_dialog.get_object("preferences_ok_button")
     ok_button.connect("clicked", self.ok_preferences_dialog)
 
   def ok_preferences_dialog(self, widget):
-    time_changed_widget = self.preferences_dialog.get_widget("preferences_dialog_spin_button_time")
-    random_order_widget = self.preferences_dialog.get_widget("preferences_dialog_show_wallpaper_random_order")
-    changing_workspace_widget = self.preferences_dialog.get_widget("preferences_dialog_change_wallpaper_changing_workspace")
-    style_widget = self.preferences_dialog.get_widget("preferences_dialog_style_combobox")
-    size_widget = self.preferences_dialog.get_widget("preferences_dialog_size_combobox")
-    preferences_dialog_widget = self.preferences_dialog.get_widget("preferences_dialog")
+    time_changed_widget = self.preferences_dialog.get_object("preferences_dialog_spin_button_time")
+    random_order_widget = self.preferences_dialog.get_object("preferences_dialog_show_wallpaper_random_order")
+    changing_workspace_widget = self.preferences_dialog.get_object("preferences_dialog_change_wallpaper_changing_workspace")
+    style_widget = self.preferences_dialog.get_object("preferences_dialog_style_combobox")
+    size_widget = self.preferences_dialog.get_object("preferences_dialog_size_combobox")
+    preferences_dialog_widget = self.preferences_dialog.get_object("preferences_dialog")
 
     # user change option for changing_workspace
     if changing_workspace_widget.get_active():
@@ -508,10 +527,17 @@ class Wallpapoz:
     if iter == None:
       return
 
-    choose_directory_dialog = gtk.glade.XML(self.wallpapoz_glade_file, "add_wallpapers_directory_dialog", APP)
-    choose_directory_dialog_widget = choose_directory_dialog.get_widget("add_wallpapers_directory_dialog")
-    filechooser_widget = choose_directory_dialog.get_widget("filechooserwidget")
-    recursive_widget = choose_directory_dialog.get_widget("recursive_checkbutton")
+    #choose_directory_dialog = gtk.glade.XML(self.wallpapoz_glade_file, "add_wallpapers_directory_dialog", APP)
+    self.choose_directory_dialog_file = "../share/wallpapoz/glade/wallpapoz-builder-add_wallpapers_directory_dialog.glade"
+    self.choose_directory_dialog_builder = gtk.Builder()
+    self.choose_directory_dialog_builder.set_translation_domain(APP)
+    self.choose_directory_dialog_builder.add_from_file(self.choose_directory_dialog_file)
+    # FIXME
+    choose_directory_dialog = self.choose_directory_dialog_builder
+
+    choose_directory_dialog_widget = choose_directory_dialog.get_object("add_wallpapers_directory_dialog")
+    filechooser_widget = choose_directory_dialog.get_object("filechooserwidget")
+    recursive_widget = choose_directory_dialog.get_object("recursive_checkbutton")
 
     # set it to last directory
     if self.last_directory == None:
@@ -528,7 +554,7 @@ class Wallpapoz:
 
     dic = { "on_cancel_add_wallpapers_directory_button_clicked" : (self.cancel_button_add_wallpapers_directory, choose_directory_dialog_widget),
             "on_add_wallpapers_directory_button_clicked" : (self.ok_button_add_wallpapers_directory, filechooser_widget, recursive_widget, choose_directory_dialog_widget, iter) }
-    choose_directory_dialog.signal_autoconnect(dic)
+    choose_directory_dialog.connect_signals(dic)
 
   # ok, if we choose the directory ( accept filechooser, recursive checkbutton, iter pointing treenode ), function add_wallpapers_directory call this function
   def ok_button_add_wallpapers_directory(self, widget, filechooser_widget, recursive_widget, choose_directory_dialog_widget, iter):
@@ -735,7 +761,7 @@ class Wallpapoz:
         ii = ii + 1
 
       # enable rename workspace menu
-      self.main_window.get_widget("rename_workspace").set_sensitive(True)
+      self.builder.get_object("rename_workspace").set_sensitive(True)
 
       # name of our left column
       left_tvcolumn_name = _("Workspace")
@@ -746,12 +772,12 @@ class Wallpapoz:
       self.store = gtk.ListStore(gobject.TYPE_INT, gobject.TYPE_STRING, gobject.TYPE_BOOLEAN)
 
       # disable cut, copy, paste, rename menu item
-      self.main_window.get_widget("cut").set_sensitive(False)
-      self.main_window.get_widget("copy").set_sensitive(False)
-      self.main_window.get_widget("paste").set_sensitive(False)
+      self.builder.get_object("cut").set_sensitive(False)
+      self.builder.get_object("copy").set_sensitive(False)
+      self.builder.get_object("paste").set_sensitive(False)
 
       # enable change wallpaper menu item
-      self.main_window.get_widget("change_wallpaper").set_sensitive(True)
+      self.builder.get_object("change_wallpaper").set_sensitive(True)
 
       # make the wallpaper list
       for i in range(len(worklist)):
@@ -786,7 +812,7 @@ class Wallpapoz:
 
     # set mode to multiple selection
     self.treeselection = self.treeview_widget.get_selection()
-    self.treeselection.set_mode(gtk.SELECTION_MULTIPLE)
+    self.treeselection.set_mode(gtk.SelectionMode.MULTIPLE)
     self.treeselection.select_path(0)
 
     # show image for liststore
@@ -814,7 +840,7 @@ class Wallpapoz:
     # status, copy or cut
     self.work_on_tree = "copy"
     # enable the paste menu item
-    self.main_window.get_widget("paste").set_sensitive(True)
+    self.builder.get_object("paste").set_sensitive(True)
 
   # we call this method when we click cut menu action
   def cut_treenode(self, widget):
@@ -829,7 +855,7 @@ class Wallpapoz:
     # status, copy or cut
     self.work_on_tree = "cut"
     # enable the paste menu item
-    self.main_window.get_widget("paste").set_sensitive(True)
+    self.builder.get_object("paste").set_sensitive(True)
 
   # helper function for reordering node after cut&paste, returning list of all lowest not selected iter from the related workspace
   def reordering_node_after_cut_and_paste(self, copy_iter_list):
@@ -942,10 +968,10 @@ class Wallpapoz:
     parent_number = self.store.get_path(self.selected_iter[0])[0]
     for single_iter in self.selected_iter:
       if self.store.get_path(single_iter)[0] != parent_number:
-	temp_iter_list = []
-	parent_number = self.store.get_path(single_iter)[0]
-      temp_iter_list.append(single_iter)
-      prev_iter = single_iter
+        temp_iter_list = []
+        parent_number = self.store.get_path(single_iter)[0]
+        temp_iter_list.append(single_iter)
+        prev_iter = single_iter
 
     # do the remaining job
     if self.store.iter_n_children( self.store.iter_parent(prev_iter) ) == len(temp_iter_list) and self.work_on_tree == "cut":
@@ -990,7 +1016,7 @@ class Wallpapoz:
       # make sure the status is reset
       self.work_on_tree = None
       # disable the paste menu item
-      self.main_window.get_widget("paste").set_sensitive(False)
+      self.builder.get_object("paste").set_sensitive(False)
 
       self.cut_and_reordering_treeiter()
 
@@ -1001,7 +1027,7 @@ class Wallpapoz:
     # workaround for the case that trying to remove a wallpaper from
     # the workspace where only one wallpaper exists
     if not lowest_iter_list:
-	return
+      return
 
     # iterate to cut ( really!!! ) the iter from selected iter list
     for single_iter in self.selected_iter:
@@ -1212,7 +1238,7 @@ class Wallpapoz:
     # make the chooser dialog
     filechooser_dialog = self.make_chooser_dialog("change")
     # if user okay with his choice, then change the value
-    if filechooser_dialog.run() == gtk.RESPONSE_OK:
+    if filechooser_dialog.run() == gtk.ResponseType.OK:
       # we interested in image file
       if self.is_image_file(filechooser_dialog.get_filename()):
         self.store.set_value(iter, 1, filechooser_dialog.get_filename())
@@ -1235,15 +1261,15 @@ class Wallpapoz:
 
     if not position_iter:
       # Nothing is selected, unfortunately this can happen
-      self.main_window.get_widget("rename_workspace").set_sensitive(False)
+      self.builder.get_object("rename_workspace").set_sensitive(False)
       self.rename_workspace_menu.set_sensitive(False)
-      self.main_window.get_widget("change_wallpaper").set_sensitive(False)
+      self.builder.get_object("change_wallpaper").set_sensitive(False)
       self.change_wallpaper_menu.set_sensitive(False)
-      self.main_window.get_widget("cut").set_sensitive(False)
+      self.builder.get_object("cut").set_sensitive(False)
       self.cut_menu.set_sensitive(False)
-      self.main_window.get_widget("copy").set_sensitive(False)
+      self.builder.get_object("copy").set_sensitive(False)
       self.copy_menu.set_sensitive(False)
-      self.main_window.get_widget("delete_wallpapers").set_sensitive(False)
+      self.builder.get_object("delete_wallpapers").set_sensitive(False)
       self.delete_wallpapers_menu.set_sensitive(False)
       # Nothing left
       return
@@ -1255,13 +1281,13 @@ class Wallpapoz:
 
       # child node
       if parent != None:
-        self.main_window.get_widget("rename_workspace").set_sensitive(False)
+        self.builder.get_object("rename_workspace").set_sensitive(False)
         self.rename_workspace_menu.set_sensitive(False)
-        self.main_window.get_widget("change_wallpaper").set_sensitive(True)
+        self.builder.get_object("change_wallpaper").set_sensitive(True)
         self.change_wallpaper_menu.set_sensitive(True)
-        self.main_window.get_widget("cut").set_sensitive(True)
+        self.builder.get_object("cut").set_sensitive(True)
         self.cut_menu.set_sensitive(True)
-        self.main_window.get_widget("copy").set_sensitive(True)
+        self.builder.get_object("copy").set_sensitive(True)
         self.copy_menu.set_sensitive(True)
 
         # See create_configuration_file
@@ -1272,23 +1298,23 @@ class Wallpapoz:
         # Only show "Delete wallpapers" menu if there are at least 2 wallpapers
         # in a workspace
         if childiter:
-          self.main_window.get_widget("delete_wallpapers").set_sensitive(True)
+          self.builder.get_object("delete_wallpapers").set_sensitive(True)
           self.delete_wallpapers_menu.set_sensitive(True)
         else:
-          self.main_window.get_widget("delete_wallpapers").set_sensitive(False)
+          self.builder.get_object("delete_wallpapers").set_sensitive(False)
           self.delete_wallpapers_menu.set_sensitive(False)
 
       # parent node
       else:
-        self.main_window.get_widget("rename_workspace").set_sensitive(True)
+        self.builder.get_object("rename_workspace").set_sensitive(True)
         self.rename_workspace_menu.set_sensitive(True)
-        self.main_window.get_widget("change_wallpaper").set_sensitive(False)
+        self.builder.get_object("change_wallpaper").set_sensitive(False)
         self.change_wallpaper_menu.set_sensitive(False)
-        self.main_window.get_widget("cut").set_sensitive(False)
+        self.builder.get_object("cut").set_sensitive(False)
         self.cut_menu.set_sensitive(False)
-        self.main_window.get_widget("copy").set_sensitive(False)
+        self.builder.get_object("copy").set_sensitive(False)
         self.copy_menu.set_sensitive(False)
-        self.main_window.get_widget("delete_wallpapers").set_sensitive(False)
+        self.builder.get_object("delete_wallpapers").set_sensitive(False)
         self.delete_wallpapers_menu.set_sensitive(False)
 
     filename = self.store.get_value(position_iter, 1)
@@ -1297,19 +1323,19 @@ class Wallpapoz:
     # files' list (i.e. not pointing to desktop name)
     if ( (type(self.store) == gtk.TreeStore) and
 	( parent == None ) ):
-	self.image_widget.clear()
+      self.image_widget.clear()
     else:
-     from glib import GError as glib_GError
+     from gi.repository.GLib import GError as glib_GError
      try:
-      anime = gtk.gdk.PixbufAnimation(filename)
+      anime = GdkPixbuf.PixbufAnimation.new_from_file(filename)
 
       if anime.is_static_image() :
         im = Image.open(filename)
         # keep image proportions
         if im.size[0] > im.size[1]:
-          self.image_widget.set_from_pixbuf(gtk.gdk.pixbuf_new_from_file_at_size(filename, 400, int((float(im.size[1])/im.size[0]) * 400)))
+          self.image_widget.set_from_pixbuf(GdkPixbuf.Pixbuf.new_from_file_at_size(filename, 400, int((float(im.size[1])/im.size[0]) * 400)))
         else:
-          self.image_widget.set_from_pixbuf(gtk.gdk.pixbuf_new_from_file_at_size(filename, int(float(im.size[1])/im.size[0] * 300), 300))
+          self.image_widget.set_from_pixbuf(GdkPixbuf.Pixbuf.new_from_file_at_size(filename, int(float(im.size[1])/im.size[0] * 300), 300))
 
       else:
         width = anime.get_width()
@@ -1322,8 +1348,8 @@ class Wallpapoz:
 
      except IOError:
       self.image_widget.clear()
-     except glib_GError, (msg):
-      print msg
+     except glib_GError as msg:
+      print (msg)
       self.image_widget.clear()
 
     # display image filename