[glade/composite-templates-new: 1/6] Added GladeWidgetAdaptor destroy_object method.

[Tristan Van Berkom <tvb src gnome org>]

commit af4ff2a61ff6f3c70dffd91e4b37dc2d326851ec
Author: Tristan Van Berkom <tristan van berkom gmail com>
Date:   Sat Apr 6 15:37:22 2013 +0900

    Added GladeWidgetAdaptor destroy_object method.
    
    The destroy_object method gives the chance to plugins to undo
    anything which might have added a reference to the object.

 gladeui/glade-widget-adaptor.c |   29 +++++++++++++++++++++++++++++
 gladeui/glade-widget-adaptor.h |   26 +++++++++++++++++++++++++-
 gladeui/glade-widget.c         |    6 +++---
 gladeui/glade-xml-utils.h      |    1 +
 plugins/gtk+/glade-gtk.c       |    9 +++++++++
 plugins/gtk+/gtk+.xml.in       |    2 +-
 6 files changed, 68 insertions(+), 5 deletions(-)
---
diff --git a/gladeui/glade-widget-adaptor.c b/gladeui/glade-widget-adaptor.c
index 1d7d172..1443763 100644
--- a/gladeui/glade-widget-adaptor.c
+++ b/gladeui/glade-widget-adaptor.c
@@ -898,6 +898,13 @@ glade_widget_adaptor_object_construct_object (GladeWidgetAdaptor *adaptor,
   return g_object_newv (adaptor->priv->type, n_parameters, parameters);
 }
 
+static void
+glade_widget_adaptor_object_destroy_object (GladeWidgetAdaptor *adaptor,
+                                           GObject            *object)
+{
+  /* Do nothing, just have a method here incase classes chain up */
+}
+
 
 static GObject *
 glade_widget_adaptor_object_get_internal_child (GladeWidgetAdaptor *adaptor,
@@ -1369,6 +1376,7 @@ glade_widget_adaptor_class_init (GladeWidgetAdaptorClass *adaptor_class)
   /* Class methods */
   adaptor_class->create_widget = glade_widget_adaptor_object_create_widget;
   adaptor_class->construct_object = glade_widget_adaptor_object_construct_object;
+  adaptor_class->destroy_object = glade_widget_adaptor_object_destroy_object;
   adaptor_class->deep_post_create = NULL;
   adaptor_class->post_create = NULL;
   adaptor_class->get_internal_child = glade_widget_adaptor_object_get_internal_child;
@@ -1530,6 +1538,11 @@ gwa_extend_with_node_load_sym (GladeWidgetAdaptorClass *klass,
     klass->construct_object = symbol;
 
   if (glade_xml_load_sym_from_node (node, module,
+                                    GLADE_TAG_DESTROY_OBJECT_FUNCTION,
+                                    &symbol))
+    klass->destroy_object = symbol;
+
+  if (glade_xml_load_sym_from_node (node, module,
                                     GLADE_TAG_DEEP_POST_CREATE_FUNCTION,
                                     &symbol))
     klass->deep_post_create = symbol;
@@ -3238,6 +3251,22 @@ glade_widget_adaptor_construct_object (GladeWidgetAdaptor *adaptor,
                                                                      parameters);
 }
 
+/**
+ * glade_widget_adaptor_destroy_object:
+ * @adaptor: A #GladeWidgetAdaptor
+ * @object: The object to destroy
+ *
+ * This function is called to destroy a GObject instance.
+ */
+void
+glade_widget_adaptor_destroy_object (GladeWidgetAdaptor *adaptor,
+                                    GObject *object)
+{
+  g_return_if_fail (GLADE_IS_WIDGET_ADAPTOR (adaptor));
+
+  GLADE_WIDGET_ADAPTOR_GET_CLASS (adaptor)->destroy_object (adaptor, object);
+}
+
 static void
 gwa_internal_children_create (GladeWidgetAdaptor *adaptor,
                               GObject *parent_object,
diff --git a/gladeui/glade-widget-adaptor.h b/gladeui/glade-widget-adaptor.h
index 6b7e357..33a4866 100644
--- a/gladeui/glade-widget-adaptor.h
+++ b/gladeui/glade-widget-adaptor.h
@@ -385,6 +385,27 @@ typedef GObject *(* GladeConstructObjectFunc)     (GladeWidgetAdaptor *adaptor,
                                                   guint               n_parameters,
                                                   GParameter         *parameters);
 
+/**
+ * GladeDestroyObjectFunc:
+ * @adaptor: A #GladeWidgetAdaptor
+ * @object: The #GObject to destroy
+ *
+ * This function is called to break any additional references to
+ * a GObject instance. Note that this function is not responsible
+ * for calling g_object_unref() on @object, the reference count
+ * of @object belongs to it's #GladeWidget wrapper.
+ *
+ * The #GtkWidget adaptor will call gtk_widget_destroy() before
+ * chaining up in this function.
+ *
+ * If your adaptor adds any references in any way at
+ * #GladePostCreateFunc time or #GladeConstructObjectFunc
+ * time, then this function must be implemented to also
+ * remove that reference.
+ *
+ */
+typedef void (* GladeDestroyObjectFunc) (GladeWidgetAdaptor *adaptor,
+                                        GObject            *object);
 
 
 /**
@@ -590,6 +611,8 @@ struct _GladeWidgetAdaptorClass
   GladeConstructObjectFunc   construct_object;  /* Object constructor
                                                 */
 
+  GladeDestroyObjectFunc     destroy_object; /* Object destructor */
+
   GladePostCreateFunc        deep_post_create;   /* Executed after widget creation: 
                                                  * plugins use this to setup various
                                                  * support codes (adaptors must always
@@ -667,7 +690,6 @@ struct _GladeWidgetAdaptorClass
   void   (* glade_reserved5)   (void);
   void   (* glade_reserved6)   (void);
   void   (* glade_reserved7)   (void);
-  void   (* glade_reserved8)   (void);
 };
 
 #define glade_widget_adaptor_create_widget(adaptor, query, ...) \
@@ -724,6 +746,8 @@ GParameter           *glade_widget_adaptor_default_params     (GladeWidgetAdapto
 GObject              *glade_widget_adaptor_construct_object   (GladeWidgetAdaptor *adaptor,
                                                               guint               n_parameters,
                                                               GParameter         *parameters);
+void                  glade_widget_adaptor_destroy_object     (GladeWidgetAdaptor *adaptor,
+                                                              GObject            *object);
 void                  glade_widget_adaptor_post_create        (GladeWidgetAdaptor *adaptor,
                                                               GObject            *object,
                                                               GladeCreateReason   reason);
diff --git a/gladeui/glade-widget.c b/gladeui/glade-widget.c
index 946392d..fc9f26a 100644
--- a/gladeui/glade-widget.c
+++ b/gladeui/glade-widget.c
@@ -3375,11 +3375,11 @@ glade_widget_set_object (GladeWidget * gwidget, GObject * new_object)
                    gwidget->priv->name ? gwidget->priv->name : "(unknown)",
                    old_object->ref_count);
 #endif
-          if (GTK_IS_WIDGET (old_object))
-            gtk_widget_destroy (GTK_WIDGET (old_object));
 
-          g_object_unref (old_object);
+         /* Have the adaptor for this widget break any additional references */
+         glade_widget_adaptor_destroy_object (gwidget->priv->adaptor, old_object);
 
+          g_object_unref (old_object);
         }
     }
   g_object_notify_by_pspec (G_OBJECT (gwidget), properties[PROP_OBJECT]);
diff --git a/gladeui/glade-xml-utils.h b/gladeui/glade-xml-utils.h
index c7b116f..ede8054 100644
--- a/gladeui/glade-xml-utils.h
+++ b/gladeui/glade-xml-utils.h
@@ -91,6 +91,7 @@ typedef struct _GladeProject        GladeProject;
 #define GLADE_TAG_REPLACE_CHILD_FUNCTION          "replace-child-function"
 #define GLADE_TAG_CREATE_WIDGET_FUNCTION          "create-widget-function"
 #define GLADE_TAG_CONSTRUCT_OBJECT_FUNCTION       "construct-object-function"
+#define GLADE_TAG_DESTROY_OBJECT_FUNCTION         "destroy-object-function"
 #define GLADE_TAG_DEEP_POST_CREATE_FUNCTION       "deep-post-create-function"
 #define GLADE_TAG_POST_CREATE_FUNCTION            "post-create-function"
 #define GLADE_TAG_GET_INTERNAL_CHILD_FUNCTION     "get-internal-child-function"
diff --git a/plugins/gtk+/glade-gtk.c b/plugins/gtk+/glade-gtk.c
index bd6f174..e729df5 100644
--- a/plugins/gtk+/glade-gtk.c
+++ b/plugins/gtk+/glade-gtk.c
@@ -94,6 +94,15 @@ glade_gtk_init (const gchar * name)
 }
 
 /* ----------------------------- GtkWidget ------------------------------ */
+void
+glade_gtk_widget_destroy_object (GladeWidgetAdaptor * adaptor,
+                                GObject *object)
+{
+  gtk_widget_destroy (GTK_WIDGET (object));
+
+  GWA_GET_CLASS (G_TYPE_OBJECT)->destroy_object (adaptor, object);
+}
+
 gboolean
 glade_gtk_widget_depends (GladeWidgetAdaptor * adaptor,
                           GladeWidget * widget, GladeWidget * another)
diff --git a/plugins/gtk+/gtk+.xml.in b/plugins/gtk+/gtk+.xml.in
index 4282b98..1db8985 100644
--- a/plugins/gtk+/gtk+.xml.in
+++ b/plugins/gtk+/gtk+.xml.in
@@ -9,6 +9,7 @@
 
     <glade-widget-class name="GtkWidget" _title="Widget" default-width="100" default-height="60">
 
+      <destroy-object-function>glade_gtk_widget_destroy_object</destroy-object-function>
       <deep-post-create-function>glade_gtk_widget_deep_post_create</deep-post-create-function>
       <set-property-function>glade_gtk_widget_set_property</set-property-function>
       <get-property-function>glade_gtk_widget_get_property</get-property-function>
@@ -19,7 +20,6 @@
       <write-widget-function>glade_gtk_widget_write_widget</write-widget-function>
       <create-editor-property-function>glade_gtk_widget_create_eprop</create-editor-property-function>
       <string-from-value-function>glade_gtk_widget_string_from_value</string-from-value-function>
-      <destroy-object-function>glade_gtk_widget_destroy_widget</destroy-object-function>
 
       <signals>
        <signal id="drag-failed" since="2.12"/>