private void pokaziDemo()
        {
            while (true)
            {
                Thread.Sleep(2000);
                LinearGradientBrush old = new LinearGradientBrush();

                IzborSmjera   izborSmjera   = null;
                IzborSoftvera izborSoftvera = null;
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    old = (LinearGradientBrush)DodajButton.Background;
                    DodajButton.Background = Brushes.Red;
                });
                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    DodajButton.Background = old;
                });

                Thread.Sleep(200);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    gridPredmeti.IsEnabled    = true;
                    DodajButton.IsEnabled     = false;
                    Odustani.Visibility       = Visibility.Visible;
                    SacuvajPredmet.Visibility = Visibility.Visible;
                    SelectedPredmet           = new Predmet();
                });
                EnableIzmijeni = false;
                EnableIzbrisi  = false;
                RezimPregled   = false;


                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    idBox.Background = Brushes.Red;
                });
                SelectedPredmet.Id = "U";
                Thread.Sleep(300);
                SelectedPredmet.Id = "U1";
                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    idBox.Background = Brushes.White;
                });
                Thread.Sleep(200);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    opisBox.Background = Brushes.Red;
                });
                SelectedPredmet.Opis = "o";
                Thread.Sleep(300);
                SelectedPredmet.Opis = "op";
                Thread.Sleep(300);
                SelectedPredmet.Opis = "opi";
                Thread.Sleep(300);
                SelectedPredmet.Opis = "opis";
                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    opisBox.Background = Brushes.White;
                });
                Thread.Sleep(200);


                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    nazivBox.Background = Brushes.Red;
                });
                SelectedPredmet.Naziv = "n";
                Thread.Sleep(300);
                SelectedPredmet.Naziv = "n1";
                Thread.Sleep(300);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    nazivBox.Background = Brushes.White;
                });
                Thread.Sleep(200);

                App.Current.Dispatcher.Invoke((Action) delegate // <--- HERE
                {
                    grupaBox.Background = Brushes.Red;
                });
                Thread.Sleep(300);
                selectedPredmet.VelicinaGrupe = 2;
                Thread.Sleep(300);
                SelectedPredmet.VelicinaGrupe = 25;
                Thread.Sleep(300);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    grupaBox.Background = Brushes.White;
                });
                Thread.Sleep(1000);

                App.Current.Dispatcher.Invoke((Action) delegate // <--- HERE
                {
                    duzinaTerminaBox.Background = Brushes.Red;
                });
                Thread.Sleep(300);
                selectedPredmet.MinDuzinaTermina = 2;
                Thread.Sleep(300);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    duzinaTerminaBox.Background = Brushes.White;
                });
                Thread.Sleep(1000);

                App.Current.Dispatcher.Invoke((Action) delegate // <--- HERE
                {
                    terminiBox.Background = Brushes.Red;
                });
                Thread.Sleep(300);
                selectedPredmet.BrojTermina = 1;
                Thread.Sleep(300);
                SelectedPredmet.BrojTermina = 15;
                Thread.Sleep(300);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    terminiBox.Background = Brushes.White;
                });
                Thread.Sleep(1000);

                App.Current.Dispatcher.Invoke((Action) delegate {
                    projektorBox.Background = Brushes.Red;
                });

                Thread.Sleep(500);
                SelectedPredmet.Projektor = true;
                App.Current.Dispatcher.Invoke((Action) delegate {
                    projektorBox.Background = Brushes.White;
                });
                Thread.Sleep(500);

                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    osBox.IsDropDownOpen = true;
                });


                Thread.Sleep(300);
                SelectedPredmet.NeophodanOS = OS.svejedno;
                Thread.Sleep(300);

                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    osBox.IsDropDownOpen = false;
                });

                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    IzaberiButton.Background = Brushes.Red;
                });


                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    izborSmjera = new IzborSmjera("demo");
                    izborSmjera.Show();
                });
                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    izborSmjera.SelectedSmjer = izborSmjera.Smjerovi[0];
                });

                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    izborSmjera.Izaberi.Background = Brushes.Red;
                });

                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    izborSmjera.Close();
                    SelectedPredmet.Smjer    = izborSmjera.SelectedSmjer;
                    IzaberiButton.Background = Brushes.Gray;
                });


                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    IzaberiSoftver.Background = Brushes.Red;
                });


                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    izborSoftvera = new IzborSoftvera("demo");
                    izborSoftvera.Show();
                });
                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    izborSoftvera.SelectedSoftver = izborSoftvera.Softveri[0];
                });

                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    izborSoftvera.Izaberi.Background = Brushes.Red;
                });

                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    SelectedPredmet.NeophodanSoftver = izborSoftvera.SelectedSoftver;
                    izborSoftvera.Close();

                    IzaberiSoftver.Background = Brushes.Gray;
                });



                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    SacuvajPredmet.Background = Brushes.Red;
                });
                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    SacuvajPredmet.Background = old;
                });
                Thread.Sleep(500);

                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    Predmeti.Add(SelectedPredmet);
                    IzaberiButton.Background = Brushes.Gray;
                    RezimPregled             = true;
                });
                RezimPregled   = true;
                EnableIzbrisi  = true;
                EnableIzmijeni = true;
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    SacuvajPredmet.Visibility  = Visibility.Hidden;
                    Odustani.Visibility        = Visibility.Hidden;
                    SacuvajIzmjenu.Visibility  = Visibility.Hidden;
                    IzmjenaOdustani.Visibility = Visibility.Hidden;
                    DodajButton.IsEnabled      = true;
                });
                Thread.Sleep(2000);

                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    IzmijeniButton.Background = Brushes.Red;
                });
                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    IzmijeniButton.Background = old;
                });

                Thread.Sleep(200);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    gridPredmeti.IsEnabled     = true;
                    DodajButton.IsEnabled      = false;
                    IzmjenaOdustani.Visibility = Visibility.Visible;
                    SacuvajIzmjenu.Visibility  = Visibility.Visible;
                });
                EnableIzmijeni = false;
                EnableIzbrisi  = false;
                RezimPregled   = false;


                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    opisBox.Background = Brushes.Red;
                });
                SelectedPredmet.Opis = "d";
                Thread.Sleep(300);
                SelectedPredmet.Opis = "dr";
                Thread.Sleep(300);
                SelectedPredmet.Opis = "dru";
                Thread.Sleep(300);
                SelectedPredmet.Opis = "drug";
                Thread.Sleep(300);
                SelectedPredmet.Opis = "drugi";
                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    opisBox.Background = Brushes.White;
                });
                Thread.Sleep(1000);

                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    SacuvajIzmjenu.Background = Brushes.Red;
                });
                Thread.Sleep(600);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    SacuvajIzmjenu.Background = old;
                });
                Thread.Sleep(500);


                RezimPregled   = true;
                EnableIzbrisi  = true;
                EnableIzmijeni = true;
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    SacuvajPredmet.Visibility  = Visibility.Hidden;
                    Odustani.Visibility        = Visibility.Hidden;
                    SacuvajIzmjenu.Visibility  = Visibility.Hidden;
                    IzmjenaOdustani.Visibility = Visibility.Hidden;
                    DodajButton.IsEnabled      = true;
                });
                Thread.Sleep(2000);

                //obrisi
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    IzbisiButton.Background = Brushes.Red;
                });
                Thread.Sleep(1000);
                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    IzbisiButton.Background = old;
                });


                Thread.Sleep(1000);

                App.Current.Dispatcher.Invoke((Action) delegate
                {
                    Predmeti.Remove(SelectedPredmet);
                    if (Predmeti.Count > 0)
                    {
                        SelectedPredmet          = Predmeti[0];
                        var item                 = dgrPredmeti.Items[0];
                        dgrPredmeti.SelectedItem = item;
                        EnableIzmijeni           = true;
                        EnableIzbrisi            = true;
                    }
                    else
                    {
                        SelectedPredmet = null;
                        EnableIzmijeni  = false;
                        EnableIzbrisi   = false;
                    }
                    RezimPregled = true;
                });

                Thread.Sleep(2000);
            }
        }
        private void IzaberiSoftver_Click(object sender, RoutedEventArgs e)
        {
            IzborSoftvera izborSoftvera = new IzborSoftvera(SoftverPage.getInstance().Softveri, SelectedPredmet.NeophodanSoftver);

            izborSoftvera.Show();
        }