diff -r 91d4f0391282 -r 56c12f44c2d3 ui/gtk/container.h
--- a/ui/gtk/container.h	Sun Oct 13 14:34:12 2024 +0200
+++ b/ui/gtk/container.h	Sun Oct 13 16:05:06 2024 +0200
@@ -124,6 +124,13 @@
     int rowspacing;
 } UiGtkTabView;
 
+typedef struct UiHeaderbarContainer {
+    UiContainer container;
+    GtkWidget *centerbox;
+    int part;
+    UiHeaderbarAlternative alternative; /* only used by fallback headerbar */
+} UiHeaderbarContainer;
+
 GtkWidget* ui_gtk_vbox_new(int spacing);
 GtkWidget* ui_gtk_hbox_new(int spacing);
 
@@ -153,6 +160,14 @@
 
 void ui_gtk_notebook_select_tab(GtkWidget *widget, int tab);
 
+#if GTK_CHECK_VERSION(3, 10, 0)
+UiContainer* ui_headerbar_container(UiObject *obj, GtkWidget *headerbar);
+void ui_headerbar_container_add(UiContainer *ct, GtkWidget *widget, UiBool fill);
+#endif
+
+UiContainer* ui_headerbar_fallback_container(UiObject *obj, GtkWidget *headerbar);
+void ui_headerbar_fallback_container_add(UiContainer *ct, GtkWidget *widget, UiBool fill);
+
 #ifdef	__cplusplus
 }
 #endif