private void EditSiteButton_Tapped(object sender, TappedRoutedEventArgs e)
        {
            var selectedSite = (Model.Site)SitesView.SelectedItem;

            SetSelectionEnabled(false);

            SiteProperties.Operation = Controls.FormOperation.Edit;
            SiteProperties.Site      = selectedSite ?? throw new Exception("Edit site button should not be active when no device is selected");

            SiteProperties.Visibility = Visibility.Visible;
            SiteProperties.SetInitialFocus();
        }
        private void AddSiteButton_Tapped(object sender, TappedRoutedEventArgs e)
        {
            var selectedTenant = TenantsView.SelectedItem as Model.Tenant;

            if (selectedTenant == null)
            {
                throw new Exception("It should not be possible to select add site if no tenant is selected");
            }

            SetSelectionEnabled(false);

            SiteProperties.Operation = Controls.FormOperation.Add;
            SiteProperties.Site      = null;
            SiteProperties.ClearForm();
            SiteProperties.TenantId   = selectedTenant.Id;
            SiteProperties.Visibility = Visibility.Visible;
            SiteProperties.SetInitialFocus();
        }