[libadwaita/wip/exalm/pref-window] preferences-window: Fix search filter visible property

[Alexander Mikhaylenko <alexm src gnome org>]

commit 2557884871d72e7e6bb6a64930f1b86f9d5be268
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Fri Apr 2 16:43:33 2021 +0500

    preferences-window: Fix search filter visible property
    
    It comes from GtkStackPage, not GtkWidget.

 src/adw-preferences-window.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/adw-preferences-window.c b/src/adw-preferences-window.c
index 9d27294..37cef92 100644
--- a/src/adw-preferences-window.c
+++ b/src/adw-preferences-window.c
@@ -551,7 +551,7 @@ adw_preferences_window_init (AdwPreferencesWindow *self)
   gtk_widget_init_template (GTK_WIDGET (self));
 
   priv->filter = GTK_FILTER (gtk_custom_filter_new ((GtkCustomFilterFunc) filter_search_results, self, 
NULL));
-  expr = gtk_property_expression_new (GTK_TYPE_WIDGET, NULL, "visible");
+  expr = gtk_property_expression_new (GTK_TYPE_STACK_PAGE, NULL, "visible");
 
   model = G_LIST_MODEL (gtk_stack_get_pages (priv->pages_stack));
   model = G_LIST_MODEL (gtk_filter_list_model_new (model, GTK_FILTER (gtk_bool_filter_new (expr))));