listbox: Explain behaviour of GtkListBoxCreateWidgetFunc

It might be an interesting shortcut for applications to use, but it
needs to be documented to be useful and agreed.

diff --git a/gtk/gtklistbox.h b/gtk/gtklistbox.h
index 0e41498bda11d81bd91b4faade944d40852080ae..68f02549f6a8f857274653cce81656bc6c7a46f1 100644 (file)
--- a/gtk/gtklistbox.h
+++ b/gtk/gtklistbox.h
@@ -121,6 +121,9 @@ typedef void (*GtkListBoxUpdateHeaderFunc) (GtkListBoxRow *row,
  * Called for list boxes that are bound to a `GListModel` with
  * gtk_list_box_bind_model() for each item that gets added to the model.
  *
+ * If the widget returned is not a #GtkListBoxRow widget, then the widget
+ * will be inserted as the child of an intermediate #GtkListBoxRow.
+ *
  * Returns: (transfer full): a `GtkWidget` that represents @item
  */
 typedef GtkWidget * (*GtkListBoxCreateWidgetFunc) (gpointer item,