[gtk/stackpage: 1/3] container: Add a function to get child metas

[Matthias Clasen <matthiasc src gnome org>]

commit 2a1ce8c3299cf42862fa6ab4227c3fddf26f535d
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Feb 6 12:52:55 2019 -0500

    container: Add a function to get child metas
    
    Add gtk_container_get_child_meta and a corresponding vfunc.
    This will be used to replace non-layout child properties.

 gtk/gtkcontainer.c | 33 +++++++++++++++++++++++++++++++++
 gtk/gtkcontainer.h |  6 +++++-
 2 files changed, 38 insertions(+), 1 deletion(-)
---
diff --git a/gtk/gtkcontainer.c b/gtk/gtkcontainer.c
index 8dd90a51ec..e6dd40940f 100644
--- a/gtk/gtkcontainer.c
+++ b/gtk/gtkcontainer.c
@@ -413,6 +413,30 @@ gtk_container_buildable_set_child_property (GtkContainer *container,
   GError *error = NULL;
   GObjectNotifyQueue *nqueue;
 
+  if (GTK_CONTAINER_GET_CLASS (container)->get_child_meta != NULL)
+    {
+      GObject *child_meta = GTK_CONTAINER_GET_CLASS (container)->get_child_meta (container, child);
+      pspec = g_object_class_find_property (G_OBJECT_GET_CLASS (child_meta), name);
+      if (pspec)
+        {
+          if (!gtk_builder_value_from_string (builder, pspec, value, &gvalue, &error))
+            {
+              g_warning ("Could not read property %s:%s with value %s of type %s: %s",
+                         g_type_name (G_OBJECT_TYPE (container)),
+                         name,
+                         value,
+                         g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspec)),
+                         error->message);
+              g_error_free (error);
+              return;
+            }
+
+          g_object_set_property (child_meta, name, &gvalue);
+          g_value_unset (&gvalue);
+          return;
+        }
+    }
+
   pspec = gtk_container_class_find_child_property (G_OBJECT_GET_CLASS (container), name);
   if (!pspec)
     {
@@ -1878,3 +1902,12 @@ gtk_container_get_path_for_child (GtkContainer *container,
   return path;
 }
 
+GObject *
+gtk_container_get_child_meta (GtkContainer *container,
+                              GtkWidget    *child)
+{
+  if (GTK_CONTAINER_GET_CLASS (container)->get_child_meta)
+    return GTK_CONTAINER_GET_CLASS (container)->get_child_meta (container, child);
+
+  return NULL;
+}
diff --git a/gtk/gtkcontainer.h b/gtk/gtkcontainer.h
index 8f07f97408..5d90fa17eb 100644
--- a/gtk/gtkcontainer.h
+++ b/gtk/gtkcontainer.h
@@ -98,6 +98,8 @@ struct _GtkContainerClass
   GtkWidgetPath * (*get_path_for_child) (GtkContainer *container,
                                          GtkWidget    *child);
 
+  GObject * (*get_child_meta) (GtkContainer *container,
+                               GtkWidget    *child);
 
   /*< private >*/
 
@@ -109,7 +111,6 @@ struct _GtkContainerClass
   void (*_gtk_reserved5) (void);
   void (*_gtk_reserved6) (void);
   void (*_gtk_reserved7) (void);
-  void (*_gtk_reserved8) (void);
 };
 
 
@@ -233,6 +234,9 @@ void    gtk_container_forall                     (GtkContainer *container,
 GDK_AVAILABLE_IN_ALL
 GtkWidgetPath * gtk_container_get_path_for_child (GtkContainer      *container,
                                                   GtkWidget         *child);
+GDK_AVAILABLE_IN_ALL
+GObject * gtk_container_get_child_meta (GtkContainer *container,
+                                        GtkWidget    *child);
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GtkContainer, g_object_unref)