Convert ETreeModel to an interface.

This commit does a number of things which I could not subdivide into
smaller commits.

* Converts ETreeModel to an interface, implemented by MessageList.

* Drops ETreeMemory and ETreeMemoryCallbacks, which were ETreeModel
  subclasses.  Their functionality is subsumed by MessageList.

* MessageList drops its public ETreeModel pointer, since MessageList
  now implements ETreeModel as an interface.

* Adds message_list_set_expanded_default(), which takes over for
  e_tree_memory_set_expanded_default().

8 files changed, 130 insertions, 1140 deletions

diff --git a/e-util/Makefile.am b/e-util/Makefile.am
index e0e4bf05a1..3990c8858b 100644
--- a/e-util/Makefile.am
+++ b/e-util/Makefile.am
@@ -293,8 +293,6 @@ evolution_util_include_HEADERS =  \
 	e-text-model.h \
 	e-text.h \
 	e-timezone-dialog.h \
-	e-tree-memory-callbacks.h \
-	e-tree-memory.h \
 	e-tree-model-generator.h \
 	e-tree-model.h \
 	e-tree-selection-model.h \
@@ -538,8 +536,6 @@ libevolution_util_la_SOURCES = \
 	e-text-model.c \
 	e-text.c \
 	e-timezone-dialog.c \
-	e-tree-memory-callbacks.c \
-	e-tree-memory.c \
 	e-tree-model-generator.c \
 	e-tree-model.c \
 	e-tree-selection-model.c \
diff --git a/e-util/e-tree-memory-callbacks.c b/e-util/e-tree-memory-callbacks.c
deleted file mode 100644
index 9d2fda6e3e..0000000000
--- a/e-util/e-tree-memory-callbacks.c
+++ /dev/null
@@ -1,314 +0,0 @@
-/*
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) version 3.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with the program; if not, see <http://www.gnu.org/licenses/>
- *
- *
- * Authors:
- *		Chris Lahey <clahey@ximian.com>
- *
- * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
- *
- */
-
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
-
-#include <gtk/gtk.h>
-
-#include "e-tree-memory-callbacks.h"
-
-G_DEFINE_TYPE (ETreeMemoryCallbacks, e_tree_memory_callbacks, E_TYPE_TREE_MEMORY)
-
-static GdkPixbuf *
-etmc_icon_at (ETreeModel *etm,
-              ETreePath node)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	return etmc->icon_at (etm, node, etmc->model_data);
-}
-
-static gint
-etmc_column_count (ETreeModel *etm)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	if (etmc->column_count)
-		return etmc->column_count (etm, etmc->model_data);
-	else
-		return 0;
-}
-
-static gboolean
-etmc_has_save_id (ETreeModel *etm)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	if (etmc->has_save_id)
-		return etmc->has_save_id (etm, etmc->model_data);
-	else
-		return FALSE;
-}
-
-static gchar *
-etmc_get_save_id (ETreeModel *etm,
-                  ETreePath node)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	if (etmc->get_save_id)
-		return etmc->get_save_id (etm, node, etmc->model_data);
-	else
-		return NULL;
-}
-
-static gboolean
-etmc_has_get_node_by_id (ETreeModel *etm)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	if (etmc->has_get_node_by_id)
-		return etmc->has_get_node_by_id (etm, etmc->model_data);
-	else
-		return FALSE;
-}
-
-static ETreePath
-etmc_get_node_by_id (ETreeModel *etm,
-                     const gchar *save_id)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	if (etmc->get_node_by_id)
-		return etmc->get_node_by_id (etm, save_id, etmc->model_data);
-	else
-		return NULL;
-}
-
-static gpointer
-etmc_sort_value_at (ETreeModel *etm,
-                    ETreePath node,
-                    gint col)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	if (etmc->sort_value_at)
-		return etmc->sort_value_at (etm, node, col, etmc->model_data);
-	else
-		return etmc->value_at (etm, node, col, etmc->model_data);
-}
-
-static gpointer
-etmc_value_at (ETreeModel *etm,
-               ETreePath node,
-               gint col)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	return etmc->value_at (etm, node, col, etmc->model_data);
-}
-
-static void
-etmc_set_value_at (ETreeModel *etm,
-                   ETreePath node,
-                   gint col,
-                   gconstpointer val)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	etmc->set_value_at (etm, node, col, val, etmc->model_data);
-}
-
-static gboolean
-etmc_is_editable (ETreeModel *etm,
-                  ETreePath node,
-                  gint col)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	return etmc->is_editable (etm, node, col, etmc->model_data);
-}
-
-/* The default for etmc_duplicate_value is to return the raw value. */
-static gpointer
-etmc_duplicate_value (ETreeModel *etm,
-                      gint col,
-                      gconstpointer value)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	if (etmc->duplicate_value)
-		return etmc->duplicate_value (etm, col, value, etmc->model_data);
-	else
-		return (gpointer) value;
-}
-
-static void
-etmc_free_value (ETreeModel *etm,
-                 gint col,
-                 gpointer value)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	if (etmc->free_value)
-		etmc->free_value (etm, col, value, etmc->model_data);
-}
-
-static gpointer
-etmc_initialize_value (ETreeModel *etm,
-                       gint col)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	if (etmc->initialize_value)
-		return etmc->initialize_value (etm, col, etmc->model_data);
-	else
-		return NULL;
-}
-
-static gboolean
-etmc_value_is_empty (ETreeModel *etm,
-                     gint col,
-                     gconstpointer value)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	if (etmc->value_is_empty)
-		return etmc->value_is_empty (etm, col, value, etmc->model_data);
-	else
-		return FALSE;
-}
-
-static gchar *
-etmc_value_to_string (ETreeModel *etm,
-                      gint col,
-                      gconstpointer value)
-{
-	ETreeMemoryCallbacks *etmc = E_TREE_MEMORY_CALLBACKS (etm);
-
-	if (etmc->value_to_string)
-		return etmc->value_to_string (etm, col, value, etmc->model_data);
-	else
-		return g_strdup ("");
-}
-
-static void
-e_tree_memory_callbacks_class_init (ETreeMemoryCallbacksClass *class)
-{
-	ETreeModelClass *model_class        = E_TREE_MODEL_CLASS (class);
-
-	model_class->icon_at            = etmc_icon_at;
-
-	model_class->column_count       = etmc_column_count;
-
-	model_class->has_save_id        = etmc_has_save_id;
-	model_class->get_save_id        = etmc_get_save_id;
-
-	model_class->has_get_node_by_id = etmc_has_get_node_by_id;
-	model_class->get_node_by_id     = etmc_get_node_by_id;
-
-	model_class->sort_value_at	= etmc_sort_value_at;
-	model_class->value_at           = etmc_value_at;
-	model_class->set_value_at       = etmc_set_value_at;
-	model_class->is_editable        = etmc_is_editable;
-
-	model_class->duplicate_value    = etmc_duplicate_value;
-	model_class->free_value         = etmc_free_value;
-	model_class->initialize_value   = etmc_initialize_value;
-	model_class->value_is_empty     = etmc_value_is_empty;
-	model_class->value_to_string    = etmc_value_to_string;
-}
-
-static void
-e_tree_memory_callbacks_init (ETreeMemoryCallbacks *etmc)
-{
-	/* nothing to do */
-}
-
-/**
- * e_tree_memory_callbacks_new:
- *
- * This initializes a new ETreeMemoryCallbacksModel object.
- * ETreeMemoryCallbacksModel is an implementaiton of the somewhat
- * abstract class ETreeMemory.  The ETreeMemoryCallbacksModel is
- * designed to allow people to easily create ETreeMemorys without
- * having to create a new GType derived from ETreeMemory every time
- * they need one.
- *
- * Instead, ETreeMemoryCallbacksModel uses a setup based in callback functions, every
- * callback function signature mimics the signature of each ETreeModel method
- * and passes the extra @data pointer to each one of the method to provide them
- * with any context they might want to use.
- *
- * ETreeMemoryCallbacks is to ETreeMemory as ETableSimple is to ETableModel.
- *
- * Return value: An ETreeMemoryCallbacks object (which is also an
- * ETreeMemory and thus an ETreeModel object).
- *
- */
-ETreeModel *
-e_tree_memory_callbacks_new (ETreeMemoryCallbacksIconAtFn icon_at,
-
-                             ETreeMemoryCallbacksColumnCountFn column_count,
-
-                             ETreeMemoryCallbacksHasSaveIdFn has_save_id,
-                             ETreeMemoryCallbacksGetSaveIdFn get_save_id,
-
-                             ETreeMemoryCallbacksHasGetNodeByIdFn has_get_node_by_id,
-                             ETreeMemoryCallbacksGetNodeByIdFn get_node_by_id,
-
-                             ETreeMemoryCallbacksValueAtFn sort_value_at,
-                             ETreeMemoryCallbacksValueAtFn value_at,
-                             ETreeMemoryCallbacksSetValueAtFn set_value_at,
-                             ETreeMemoryCallbacksIsEditableFn is_editable,
-
-                             ETreeMemoryCallbacksDuplicateValueFn duplicate_value,
-                             ETreeMemoryCallbacksFreeValueFn free_value,
-                             ETreeMemoryCallbacksInitializeValueFn initialize_value,
-                             ETreeMemoryCallbacksValueIsEmptyFn value_is_empty,
-                             ETreeMemoryCallbacksValueToStringFn value_to_string,
-
-                             gpointer model_data)
-{
-	ETreeMemoryCallbacks *etmc;
-
-	etmc = g_object_new (E_TYPE_TREE_MEMORY_CALLBACKS, NULL);
-
-	etmc->icon_at            = icon_at;
-
-	etmc->column_count       = column_count;
-
-	etmc->has_save_id        = has_save_id;
-	etmc->get_save_id        = get_save_id;
-
-	etmc->has_get_node_by_id = has_get_node_by_id;
-	etmc->get_node_by_id     = get_node_by_id;
-
-	etmc->sort_value_at	 = sort_value_at;
-	etmc->value_at           = value_at;
-	etmc->set_value_at       = set_value_at;
-	etmc->is_editable        = is_editable;
-
-	etmc->duplicate_value    = duplicate_value;
-	etmc->free_value         = free_value;
-	etmc->initialize_value   = initialize_value;
-	etmc->value_is_empty     = value_is_empty;
-	etmc->value_to_string    = value_to_string;
-
-	etmc->model_data         = model_data;
-
-	return (ETreeModel *) etmc;
-}
-
diff --git a/e-util/e-tree-memory-callbacks.h b/e-util/e-tree-memory-callbacks.h
deleted file mode 100644
index df47e9a491..0000000000
--- a/e-util/e-tree-memory-callbacks.h
+++ /dev/null
@@ -1,182 +0,0 @@
-/*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) version 3.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with the program; if not, see <http://www.gnu.org/licenses/>
- *
- *
- * Authors:
- *		Chris Lahey <clahey@ximian.com>
- *
- * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
- *
- */
-
-#if !defined (__E_UTIL_H_INSIDE__) && !defined (LIBEUTIL_COMPILATION)
-#error "Only <e-util/e-util.h> should be included directly."
-#endif
-
-#ifndef _E_TREE_MEMORY_CALLBACKS_H_
-#define _E_TREE_MEMORY_CALLBACKS_H_
-
-#include <e-util/e-tree-memory.h>
-
-/* Standard GObject macros */
-#define E_TYPE_TREE_MEMORY_CALLBACKS \
-	(e_tree_memory_callbacks_get_type ())
-#define E_TREE_MEMORY_CALLBACKS(obj) \
-	(G_TYPE_CHECK_INSTANCE_CAST \
-	((obj), E_TYPE_TREE_MEMORY_CALLBACKS, ETreeMemoryCallbacks))
-#define E_TREE_MEMORY_CALLBACKS_CLASS(cls) \
-	(G_TYPE_CHECK_CLASS_CAST \
-	((cls), E_TYPE_TREE_MEMORY_CALLBACKS, ETreeMemoryCallbacksClass))
-#define E_IS_TREE_MEMORY_CALLBACKS(obj) \
-	(G_TYPE_CHECK_INSTANCE_TYPE \
-	((obj), E_TYPE_TREE_MEMORY_CALLBACKS))
-#define E_IS_TREE_MEMORY_CALLBACKS_CLASS(cls) \
-	(G_TYPE_CHECK_CLASS_TYPE \
-	((cls), E_TYPE_TREE_MEMORY_CALLBACKS))
-#define E_TREE_MEMORY_CALLBACKS_GET_CLASS(obj) \
-	(G_TYPE_INSTANCE_GET_CLASS \
-	((obj), E_TYPE_TREE_MEMORY_CALLBACKS, ETreeMemoryCallbacksClass))
-
-G_BEGIN_DECLS
-
-typedef struct _ETreeMemoryCallbacks ETreeMemoryCallbacks;
-typedef struct _ETreeMemoryCallbacksClass ETreeMemoryCallbacksClass;
-
-typedef GdkPixbuf *	(*ETreeMemoryCallbacksIconAtFn)
-						(ETreeModel *etree,
-						 ETreePath path,
-						 gpointer model_data);
-
-typedef gint		(*ETreeMemoryCallbacksColumnCountFn)
-						(ETreeModel *etree,
-						 gpointer model_data);
-
-typedef gboolean	(*ETreeMemoryCallbacksHasSaveIdFn)
-						(ETreeModel *etree,
-						 gpointer model_data);
-typedef gchar *		(*ETreeMemoryCallbacksGetSaveIdFn)
-						(ETreeModel *etree,
-						 ETreePath path,
-						 gpointer model_data);
-
-typedef gboolean	(*ETreeMemoryCallbacksHasGetNodeByIdFn)
-						(ETreeModel *etree,
-						 gpointer model_data);
-typedef ETreePath	(*ETreeMemoryCallbacksGetNodeByIdFn)
-						(ETreeModel *etree,
-						 const gchar *save_id,
-						 gpointer model_data);
-
-typedef gpointer	(*ETreeMemoryCallbacksValueAtFn)
-						(ETreeModel *etree,
-						 ETreePath path,
-						 gint col,
-						 gpointer model_data);
-typedef void		(*ETreeMemoryCallbacksSetValueAtFn)
-						(ETreeModel *etree,
-						 ETreePath path,
-						 gint col,
-						 gconstpointer val,
-						 gpointer model_data);
-typedef gboolean	(*ETreeMemoryCallbacksIsEditableFn)
-						(ETreeModel *etree,
-						 ETreePath path,
-						 gint col,
-						 gpointer model_data);
-
-typedef gpointer	(*ETreeMemoryCallbacksDuplicateValueFn)
-						(ETreeModel *etm,
-						 gint col,
-						 gconstpointer val,
-						 gpointer data);
-typedef void		(*ETreeMemoryCallbacksFreeValueFn)
-						(ETreeModel *etm,
-						 gint col,
-						 gpointer val,
-						 gpointer data);
-typedef gpointer	(*ETreeMemoryCallbacksInitializeValueFn)
-						(ETreeModel *etm,
-						 gint col,
-						 gpointer data);
-typedef gboolean	(*ETreeMemoryCallbacksValueIsEmptyFn)
-						(ETreeModel *etm,
-						 gint col,
-						 gconstpointer val,
-						 gpointer data);
-typedef gchar *		(*ETreeMemoryCallbacksValueToStringFn)
-						(ETreeModel *etm,
-						 gint col,
-						 gconstpointer val,
-						 gpointer data);
-
-struct _ETreeMemoryCallbacks {
-	ETreeMemory parent;
-
-	ETreeMemoryCallbacksIconAtFn icon_at;
-
-	ETreeMemoryCallbacksColumnCountFn     column_count;
-
-	ETreeMemoryCallbacksHasSaveIdFn       has_save_id;
-	ETreeMemoryCallbacksGetSaveIdFn       get_save_id;
-
-	ETreeMemoryCallbacksHasGetNodeByIdFn  has_get_node_by_id;
-	ETreeMemoryCallbacksGetNodeByIdFn     get_node_by_id;
-
-	ETreeMemoryCallbacksValueAtFn         sort_value_at;
-	ETreeMemoryCallbacksValueAtFn         value_at;
-	ETreeMemoryCallbacksSetValueAtFn      set_value_at;
-	ETreeMemoryCallbacksIsEditableFn      is_editable;
-
-	ETreeMemoryCallbacksDuplicateValueFn  duplicate_value;
-	ETreeMemoryCallbacksFreeValueFn       free_value;
-	ETreeMemoryCallbacksInitializeValueFn initialize_value;
-	ETreeMemoryCallbacksValueIsEmptyFn    value_is_empty;
-	ETreeMemoryCallbacksValueToStringFn   value_to_string;
-
-	gpointer model_data;
-};
-
-struct _ETreeMemoryCallbacksClass {
-	ETreeMemoryClass parent_class;
-};
-
-GType		e_tree_memory_callbacks_get_type
-				(void) G_GNUC_CONST;
-ETreeModel *	e_tree_memory_callbacks_new
-				(ETreeMemoryCallbacksIconAtFn icon_at,
-
-				 ETreeMemoryCallbacksColumnCountFn column_count,
-
-				 ETreeMemoryCallbacksHasSaveIdFn has_save_id,
-				 ETreeMemoryCallbacksGetSaveIdFn get_save_id,
-
-				 ETreeMemoryCallbacksHasGetNodeByIdFn has_get_node_by_id,
-				 ETreeMemoryCallbacksGetNodeByIdFn get_node_by_id,
-
-				 ETreeMemoryCallbacksValueAtFn sort_value_at,
-				 ETreeMemoryCallbacksValueAtFn value_at,
-				 ETreeMemoryCallbacksSetValueAtFn set_value_at,
-				 ETreeMemoryCallbacksIsEditableFn is_editable,
-
-				 ETreeMemoryCallbacksDuplicateValueFn duplicate_value,
-				 ETreeMemoryCallbacksFreeValueFn free_value,
-				 ETreeMemoryCallbacksInitializeValueFn initialize_value,
-				 ETreeMemoryCallbacksValueIsEmptyFn value_is_empty,
-				 ETreeMemoryCallbacksValueToStringFn value_to_string,
-
-				 gpointer model_data);
-
-G_END_DECLS
-
-#endif /* _E_TREE_MEMORY_CALLBACKS_H_ */
diff --git a/e-util/e-tree-memory.c b/e-util/e-tree-memory.c
deleted file mode 100644
index 743aab010d..0000000000
--- a/e-util/e-tree-memory.c
+++ /dev/null
@@ -1,356 +0,0 @@
-/*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) version 3.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with the program; if not, see <http://www.gnu.org/licenses/>
- *
- *
- * Authors:
- *		Chris Lahey <clahey@ximian.com>
- *		Chris Toshok <toshok@ximian.com>
- *
- * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
- *
- */
-
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
-
-#include "e-tree-memory.h"
-
-#include <stdio.h>
-#include <errno.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <stdlib.h>
-
-#include <libxml/parser.h>
-#include <libxml/xmlmemory.h>
-
-#include "e-xml-utils.h"
-
-#define E_TREE_MEMORY_GET_PRIVATE(obj) \
-	(G_TYPE_INSTANCE_GET_PRIVATE \
-	((obj), E_TYPE_TREE_MEMORY, ETreeMemoryPrivate))
-
-G_DEFINE_TYPE (ETreeMemory, e_tree_memory, E_TYPE_TREE_MODEL)
-
-struct _ETreeMemoryPrivate {
-	GNode *root;
-
-	/* whether nodes are created expanded
-	 * or collapsed by default */
-	gboolean expanded_default;
-
-	gint frozen;
-};
-
-static void
-tree_memory_finalize (GObject *object)
-{
-	ETreeMemoryPrivate *priv;
-
-	priv = E_TREE_MEMORY_GET_PRIVATE (object);
-
-	if (priv->root != NULL)
-		g_node_destroy (priv->root);
-
-	G_OBJECT_CLASS (e_tree_memory_parent_class)->finalize (object);
-}
-
-static ETreePath
-tree_memory_get_root (ETreeModel *etm)
-{
-	ETreeMemory *tree_memory = E_TREE_MEMORY (etm);
-
-	return tree_memory->priv->root;
-}
-
-static ETreePath
-tree_memory_get_parent (ETreeModel *etm,
-                        ETreePath path)
-{
-	return ((GNode *) path)->parent;
-}
-
-static ETreePath
-tree_memory_get_first_child (ETreeModel *etm,
-                             ETreePath path)
-{
-	return g_node_first_child ((GNode *) path);
-}
-
-static ETreePath
-tree_memory_get_next (ETreeModel *etm,
-                      ETreePath path)
-{
-	return g_node_next_sibling ((GNode *) path);
-}
-
-static gboolean
-tree_memory_is_root (ETreeModel *etm,
-                     ETreePath path)
-{
-	return G_NODE_IS_ROOT ((GNode *) path);
-}
-
-static gboolean
-tree_memory_is_expandable (ETreeModel *etm,
-                           ETreePath path)
-{
-	return (g_node_first_child ((GNode *) path) != NULL);
-}
-
-static guint
-tree_memory_get_n_children (ETreeModel *etm,
-                            ETreePath path)
-{
-	return g_node_n_children ((GNode *) path);
-}
-
-static guint
-tree_memory_depth (ETreeModel *etm,
-                   ETreePath path)
-{
-	return g_node_depth ((GNode *) path);
-}
-
-static gboolean
-tree_memory_get_expanded_default (ETreeModel *etm)
-{
-	ETreeMemory *tree_memory = E_TREE_MEMORY (etm);
-
-	return tree_memory->priv->expanded_default;
-}
-
-static void
-e_tree_memory_class_init (ETreeMemoryClass *class)
-{
-	GObjectClass *object_class;
-	ETreeModelClass *tree_model_class;
-
-	g_type_class_add_private (class, sizeof (ETreeMemoryPrivate));
-
-	object_class = G_OBJECT_CLASS (class);
-	object_class->finalize = tree_memory_finalize;
-
-	tree_model_class = E_TREE_MODEL_CLASS (class);
-	tree_model_class->get_root = tree_memory_get_root;
-	tree_model_class->get_next = tree_memory_get_next;
-	tree_model_class->get_first_child = tree_memory_get_first_child;
-	tree_model_class->get_parent = tree_memory_get_parent;
-
-	tree_model_class->is_root = tree_memory_is_root;
-	tree_model_class->is_expandable = tree_memory_is_expandable;
-	tree_model_class->get_n_children = tree_memory_get_n_children;
-	tree_model_class->depth = tree_memory_depth;
-	tree_model_class->get_expanded_default = tree_memory_get_expanded_default;
-}
-
-static void
-e_tree_memory_init (ETreeMemory *tree_memory)
-{
-	tree_memory->priv = E_TREE_MEMORY_GET_PRIVATE (tree_memory);
-}
-
-/**
- * e_tree_memory_node_insert:
- * @tree_memory:
- * @parent_node:
- * @position:
- * @data:
- *
- *
- *
- * Returns:
- **/
-ETreePath
-e_tree_memory_node_insert (ETreeMemory *tree_memory,
-                           ETreePath parent_node,
-                           gint position,
-                           gpointer data)
-{
-	GNode *new_path;
-	GNode *parent_path = parent_node;
-
-	g_return_val_if_fail (E_IS_TREE_MEMORY (tree_memory), NULL);
-
-	if (parent_path == NULL)
-		g_return_val_if_fail (tree_memory->priv->root == NULL, NULL);
-
-	if (!tree_memory->priv->frozen)
-		e_tree_model_pre_change (E_TREE_MODEL (tree_memory));
-
-	new_path = g_node_new (data);
-
-	if (parent_path != NULL) {
-		g_node_insert (parent_path, position, new_path);
-		if (!tree_memory->priv->frozen)
-			e_tree_model_node_inserted (
-				E_TREE_MODEL (tree_memory),
-				parent_path, new_path);
-	} else {
-		tree_memory->priv->root = new_path;
-		if (!tree_memory->priv->frozen)
-			e_tree_model_node_changed (
-				E_TREE_MODEL (tree_memory), new_path);
-	}
-
-	return new_path;
-}
-
-/**
- * e_tree_memory_node_remove:
- * @tree_memory:
- * @node:
- *
- *
- *
- * Returns:
- **/
-gpointer
-e_tree_memory_node_remove (ETreeMemory *tree_memory,
-                           ETreePath node)
-{
-	GNode *path = node;
-	GNode *parent = path->parent;
-	GNode *sibling;
-	gpointer ret = path->data;
-	gint old_position = 0;
-
-	g_return_val_if_fail (E_IS_TREE_MEMORY (tree_memory), NULL);
-
-	if (!tree_memory->priv->frozen) {
-		e_tree_model_pre_change (E_TREE_MODEL (tree_memory));
-		for (old_position = 0, sibling = path;
-		     sibling;
-		     old_position++, sibling = sibling->prev)
-			/* Empty intentionally*/;
-		old_position--;
-	}
-
-	/* unlink this node - we only have to unlink the root node being
-	 * removed, since the others are only references from this node */
-	g_node_unlink (path);
-
-	/*printf("removing %d nodes from position %d\n", visible, base);*/
-	if (!tree_memory->priv->frozen)
-		e_tree_model_node_removed (
-			E_TREE_MODEL (tree_memory),
-			parent, path, old_position);
-
-	g_node_destroy (path);
-
-	if (path == tree_memory->priv->root)
-		tree_memory->priv->root = NULL;
-
-	if (!tree_memory->priv->frozen)
-		e_tree_model_node_deleted (E_TREE_MODEL (tree_memory), path);
-
-	return ret;
-}
-
-/**
- * e_tree_memory_freeze:
- * @tree_memory: the ETreeModel to freeze.
- *
- * This function prepares an ETreeModel for a period of much change.
- * All signals regarding changes to the tree are deferred until we
- * thaw the tree.
- *
- **/
-void
-e_tree_memory_freeze (ETreeMemory *tree_memory)
-{
-	g_return_if_fail (E_IS_TREE_MEMORY (tree_memory));
-
-	if (tree_memory->priv->frozen == 0)
-		e_tree_model_pre_change (E_TREE_MODEL (tree_memory));
-
-	tree_memory->priv->frozen++;
-}
-
-/**
- * e_tree_memory_thaw:
- * @tree_memory: the ETreeMemory to thaw.
- *
- * This function thaws an ETreeMemory.  All the defered signals can add
- * up to a lot, we don't know - so we just emit a model_changed
- * signal.
- *
- **/
-void
-e_tree_memory_thaw (ETreeMemory *tree_memory)
-{
-	g_return_if_fail (E_IS_TREE_MEMORY (tree_memory));
-
-	if (tree_memory->priv->frozen > 0)
-		tree_memory->priv->frozen--;
-
-	if (tree_memory->priv->frozen == 0)
-		e_tree_model_node_changed (
-			E_TREE_MODEL (tree_memory),
-			tree_memory->priv->root);
-}
-
-/**
- * e_tree_memory_set_expanded_default
- *
- * Sets the state of nodes to be append to a thread.
- * They will either be expanded or collapsed, according to
- * the value of @expanded.
- */
-void
-e_tree_memory_set_expanded_default (ETreeMemory *tree_memory,
-                                    gboolean expanded)
-{
-	g_return_if_fail (E_IS_TREE_MEMORY (tree_memory));
-
-	tree_memory->priv->expanded_default = expanded;
-}
-
-/**
- * e_tree_memory_node_get_data:
- * @tree_memory:
- * @path:
- *
- *
- *
- * Return value:
- **/
-gpointer
-e_tree_memory_node_get_data (ETreeMemory *tree_memory,
-                             ETreePath path)
-{
-	g_return_val_if_fail (path != NULL, NULL);
-
-	return ((GNode *) path)->data;
-}
-
-/**
- * e_tree_memory_node_set_data:
- * @tree_memory:
- * @path:
- * @data:
- *
- *
- **/
-void
-e_tree_memory_node_set_data (ETreeMemory *tree_memory,
-                             ETreePath path,
-                             gpointer data)
-{
-	g_return_if_fail (path != NULL);
-
-	((GNode *) path)->data = data;
-}
-
diff --git a/e-util/e-tree-memory.h b/e-util/e-tree-memory.h
deleted file mode 100644
index f7a386ecf6..0000000000
--- a/e-util/e-tree-memory.h
+++ /dev/null
@@ -1,93 +0,0 @@
-/*
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) version 3.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with the program; if not, see <http://www.gnu.org/licenses/>
- *
- *
- * Authors:
- *		Chris Lahey <clahey@ximian.com>
- *		Chris Toshok <toshok@ximian.com>
- *
- * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
- *
- */
-
-#if !defined (__E_UTIL_H_INSIDE__) && !defined (LIBEUTIL_COMPILATION)
-#error "Only <e-util/e-util.h> should be included directly."
-#endif
-
-#ifndef E_TREE_MEMORY_H
-#define E_TREE_MEMORY_H
-
-#include <e-util/e-tree-model.h>
-
-/* Standard GObject macros */
-#define E_TYPE_TREE_MEMORY \
-	(e_tree_memory_get_type ())
-#define E_TREE_MEMORY(obj) \
-	(G_TYPE_CHECK_INSTANCE_CAST \
-	((obj), E_TYPE_TREE_MEMORY, ETreeMemory))
-#define E_TREE_MEMORY_CLASS(cls) \
-	(G_TYPE_CHECK_CLASS_CAST \
-	((cls), E_TYPE_TREE_MEMORY, ETreeMemoryClass))
-#define E_IS_TREE_MEMORY(obj) \
-	(G_TYPE_CHECK_INSTANCE_TYPE \
-	((obj), E_TYPE_TREE_MEMORY))
-#define E_IS_TREE_MEMORY_CLASS(cls) \
-	(G_TYPE_CHECK_CLASS_TYPE \
-	((cls), E_TYPE_TREE_MEMORY))
-#define E_TREE_MEMORY_GET_CLASS(obj) \
-	(G_TYPE_INSTANCE_GET_CLASS \
-	((obj), E_TYPE_TREE_MEMORY, ETreeMemoryClass))
-
-G_BEGIN_DECLS
-
-typedef struct _ETreeMemory ETreeMemory;
-typedef struct _ETreeMemoryClass ETreeMemoryClass;
-typedef struct _ETreeMemoryPrivate ETreeMemoryPrivate;
-
-struct _ETreeMemory {
-	ETreeModel parent;
-	ETreeMemoryPrivate *priv;
-};
-
-struct _ETreeMemoryClass {
-	ETreeModelClass parent_class;
-};
-
-GType		e_tree_memory_get_type		(void) G_GNUC_CONST;
-
-/* node operations */
-ETreePath	e_tree_memory_node_insert	(ETreeMemory *tree_memory,
-						 ETreePath parent_node,
-						 gint position,
-						 gpointer data);
-gpointer	e_tree_memory_node_remove	(ETreeMemory *tree_memory,
-						 ETreePath node);
-
-/* Freeze and thaw */
-void		e_tree_memory_freeze		(ETreeMemory *tree_memory);
-void		e_tree_memory_thaw		(ETreeMemory *tree_memory);
-void		e_tree_memory_set_expanded_default
-						(ETreeMemory *tree_memory,
-						 gboolean expanded);
-gpointer	e_tree_memory_node_get_data	(ETreeMemory *tree_memory,
-						 ETreePath path);
-void		e_tree_memory_node_set_data	(ETreeMemory *tree_memory,
-						 ETreePath path,
-						 gpointer data);
-
-G_END_DECLS
-
-#endif /* E_TREE_MEMORY_H */
-
diff --git a/e-util/e-tree-model.c b/e-util/e-tree-model.c
index d469d23da4..f9bf28a3a2 100644
--- a/e-util/e-tree-model.c
+++ b/e-util/e-tree-model.c
@@ -1,4 +1,6 @@
 /*
+ * e-tree-model.c
+ *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
@@ -12,37 +14,10 @@
  * You should have received a copy of the GNU Lesser General Public
  * License along with the program; if not, see <http://www.gnu.org/licenses/>
  *
- *
- * Authors:
- *		Chris Lahey  <clahey@ximian.com>
- *		Chris Toshok <toshok@ximian.com>
- *
- * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
- *
  */
 
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
-
 #include "e-tree-model.h"
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <fcntl.h>
-
-#include <gtk/gtk.h>
-#include <libxml/parser.h>
-#include <libxml/xmlmemory.h>
-
-#include "e-marshal.h"
-#include "e-xml-utils.h"
-
-#define d(x)
-
-G_DEFINE_TYPE (ETreeModel, e_tree_model, G_TYPE_OBJECT)
-
 enum {
 	PRE_CHANGE,
 	NODE_CHANGED,
@@ -54,69 +29,63 @@ enum {
 	LAST_SIGNAL
 };
 
-static guint signals[LAST_SIGNAL] = {0, };
+static guint signals[LAST_SIGNAL];
+
+G_DEFINE_INTERFACE (ETreeModel, e_tree_model, G_TYPE_OBJECT)
 
 static void
-e_tree_model_class_init (ETreeModelClass *class)
+e_tree_model_default_init (ETreeModelInterface *interface)
 {
-	GObjectClass *object_class = G_OBJECT_CLASS (class);
-
 	signals[PRE_CHANGE] = g_signal_new (
 		"pre_change",
-		G_TYPE_FROM_CLASS (object_class),
+		G_TYPE_FROM_INTERFACE (interface),
 		G_SIGNAL_RUN_LAST,
-		G_STRUCT_OFFSET (ETreeModelClass, pre_change),
-		(GSignalAccumulator) NULL, NULL,
-		g_cclosure_marshal_VOID__VOID,
+		G_STRUCT_OFFSET (ETreeModelInterface, pre_change),
+		NULL, NULL, NULL,
 		G_TYPE_NONE, 0);
 
 	signals[REBUILT] = g_signal_new (
 		"rebuilt",
-		G_TYPE_FROM_CLASS (object_class),
+		G_TYPE_FROM_INTERFACE (interface),
 		G_SIGNAL_RUN_LAST,
-		G_STRUCT_OFFSET (ETreeModelClass, rebuilt),
-		(GSignalAccumulator) NULL, NULL,
-		g_cclosure_marshal_VOID__VOID,
+		G_STRUCT_OFFSET (ETreeModelInterface, rebuilt),
+		NULL, NULL, NULL,
 		G_TYPE_NONE, 0);
 
 	signals[NODE_CHANGED] = g_signal_new (
 		"node_changed",
-		G_TYPE_FROM_CLASS (object_class),
+		G_TYPE_FROM_INTERFACE (interface),
 		G_SIGNAL_RUN_LAST,
-		G_STRUCT_OFFSET (ETreeModelClass, node_changed),
-		(GSignalAccumulator) NULL, NULL,
-		g_cclosure_marshal_VOID__POINTER,
+		G_STRUCT_OFFSET (ETreeModelInterface, node_changed),
+		NULL, NULL, NULL,
 		G_TYPE_NONE, 1,
 		G_TYPE_POINTER);
 
 	signals[NODE_DATA_CHANGED] = g_signal_new (
 		"node_data_changed",
-		G_TYPE_FROM_CLASS (object_class),
+		G_TYPE_FROM_INTERFACE (interface),
 		G_SIGNAL_RUN_LAST,
-		G_STRUCT_OFFSET (ETreeModelClass, node_data_changed),
-		(GSignalAccumulator) NULL, NULL,
-		g_cclosure_marshal_VOID__POINTER,
+		G_STRUCT_OFFSET (ETreeModelInterface, node_data_changed),
+		NULL, NULL, NULL,
 		G_TYPE_NONE, 1,
 		G_TYPE_POINTER);
 
 	signals[NODE_INSERTED] = g_signal_new (
 		"node_inserted",
-		G_TYPE_FROM_CLASS (object_class),
+		G_TYPE_FROM_INTERFACE (interface),
 		G_SIGNAL_RUN_LAST,
-		G_STRUCT_OFFSET (ETreeModelClass, node_inserted),
-		(GSignalAccumulator) NULL, NULL,
-		e_marshal_VOID__POINTER_POINTER,
+		G_STRUCT_OFFSET (ETreeModelInterface, node_inserted),
+		NULL, NULL, NULL,
 		G_TYPE_NONE, 2,
 		G_TYPE_POINTER,
 		G_TYPE_POINTER);
 
 	signals[NODE_REMOVED] = g_signal_new (
 		"node_removed",
-		G_TYPE_FROM_CLASS (object_class),
+		G_TYPE_FROM_INTERFACE (interface),
 		G_SIGNAL_RUN_LAST,
-		G_STRUCT_OFFSET (ETreeModelClass, node_removed),
-		(GSignalAccumulator) NULL, NULL,
-		e_marshal_VOID__POINTER_POINTER_INT,
+		G_STRUCT_OFFSET (ETreeModelInterface, node_removed),
+		NULL, NULL, NULL,
 		G_TYPE_NONE, 3,
 		G_TYPE_POINTER,
 		G_TYPE_POINTER,
@@ -124,23 +93,14 @@ e_tree_model_class_init (ETreeModelClass *class)
 
 	signals[NODE_DELETED] = g_signal_new (
 		"node_deleted",
-		G_TYPE_FROM_CLASS (object_class),
+		G_TYPE_FROM_INTERFACE (interface),
 		G_SIGNAL_RUN_LAST,
-		G_STRUCT_OFFSET (ETreeModelClass, node_deleted),
-		(GSignalAccumulator) NULL, NULL,
-		g_cclosure_marshal_VOID__POINTER,
+		G_STRUCT_OFFSET (ETreeModelInterface, node_deleted),
+		NULL, NULL, NULL,
 		G_TYPE_NONE, 1,
 		G_TYPE_POINTER);
 }
 
-static void
-e_tree_model_init (ETreeModel *tree_model)
-{
-	/* nothing to do */
-}
-
-/* signals */
-
 /**
  * e_tree_model_pre_change:
  * @tree_model:
@@ -272,14 +232,14 @@ e_tree_model_node_deleted (ETreeModel *tree_model,
 ETreePath
 e_tree_model_get_root (ETreeModel *tree_model)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), NULL);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->get_root != NULL, NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->get_root != NULL, NULL);
 
-	return class->get_root (tree_model);
+	return interface->get_root (tree_model);
 }
 
 /**
@@ -295,14 +255,14 @@ ETreePath
 e_tree_model_node_get_parent (ETreeModel *tree_model,
                               ETreePath path)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), NULL);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->get_parent != NULL, NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->get_parent != NULL, NULL);
 
-	return class->get_parent (tree_model, path);
+	return interface->get_parent (tree_model, path);
 }
 
 /**
@@ -318,14 +278,14 @@ ETreePath
 e_tree_model_node_get_first_child (ETreeModel *tree_model,
                                    ETreePath path)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), NULL);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->get_first_child != NULL, NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->get_first_child != NULL, NULL);
 
-	return class->get_first_child (tree_model, path);
+	return interface->get_first_child (tree_model, path);
 }
 
 /**
@@ -341,14 +301,14 @@ ETreePath
 e_tree_model_node_get_next (ETreeModel *tree_model,
                             ETreePath path)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), NULL);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->get_next != NULL, NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->get_next != NULL, NULL);
 
-	return class->get_next (tree_model, path);
+	return interface->get_next (tree_model, path);
 }
 
 /**
@@ -364,14 +324,14 @@ gboolean
 e_tree_model_node_is_root (ETreeModel *tree_model,
                            ETreePath path)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), FALSE);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->is_root != NULL, FALSE);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->is_root != NULL, FALSE);
 
-	return class->is_root (tree_model, path);
+	return interface->is_root (tree_model, path);
 }
 
 /**
@@ -387,29 +347,29 @@ gboolean
 e_tree_model_node_is_expandable (ETreeModel *tree_model,
                                  ETreePath path)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), FALSE);
 	g_return_val_if_fail (path != NULL, FALSE);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->is_expandable != NULL, FALSE);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->is_expandable != NULL, FALSE);
 
-	return class->is_expandable (tree_model, path);
+	return interface->is_expandable (tree_model, path);
 }
 
 guint
 e_tree_model_node_get_n_children (ETreeModel *tree_model,
                                   ETreePath path)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), 0);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->get_n_children != NULL, 0);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->get_n_children != NULL, 0);
 
-	return class->get_n_children (tree_model, path);
+	return interface->get_n_children (tree_model, path);
 }
 
 /**
@@ -425,14 +385,14 @@ guint
 e_tree_model_node_depth (ETreeModel *tree_model,
                          ETreePath path)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), 0);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->depth != NULL, 0);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->depth != NULL, 0);
 
-	return class->depth (tree_model, path);
+	return interface->depth (tree_model, path);
 }
 
 /**
@@ -448,14 +408,14 @@ GdkPixbuf *
 e_tree_model_icon_at (ETreeModel *tree_model,
                       ETreePath path)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), NULL);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->icon_at != NULL, NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->icon_at != NULL, NULL);
 
-	return class->icon_at (tree_model, path);
+	return interface->icon_at (tree_model, path);
 }
 
 /**
@@ -469,14 +429,14 @@ e_tree_model_icon_at (ETreeModel *tree_model,
 gboolean
 e_tree_model_get_expanded_default (ETreeModel *tree_model)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), FALSE);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->get_expanded_default != NULL, FALSE);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->get_expanded_default != NULL, FALSE);
 
-	return class->get_expanded_default (tree_model);
+	return interface->get_expanded_default (tree_model);
 }
 
 /**
@@ -490,14 +450,14 @@ e_tree_model_get_expanded_default (ETreeModel *tree_model)
 gint
 e_tree_model_column_count (ETreeModel *tree_model)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), 0);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->column_count != NULL, 0);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->column_count != NULL, 0);
 
-	return class->column_count (tree_model);
+	return interface->column_count (tree_model);
 }
 
 /**
@@ -511,14 +471,14 @@ e_tree_model_column_count (ETreeModel *tree_model)
 gboolean
 e_tree_model_has_save_id (ETreeModel *tree_model)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), FALSE);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->has_save_id != NULL, FALSE);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->has_save_id != NULL, FALSE);
 
-	return class->has_save_id (tree_model);
+	return interface->has_save_id (tree_model);
 }
 
 /**
@@ -534,14 +494,14 @@ gchar *
 e_tree_model_get_save_id (ETreeModel *tree_model,
                           ETreePath path)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), NULL);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->get_save_id != NULL, NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->get_save_id != NULL, NULL);
 
-	return class->get_save_id (tree_model, path);
+	return interface->get_save_id (tree_model, path);
 }
 
 /**
@@ -555,14 +515,14 @@ e_tree_model_get_save_id (ETreeModel *tree_model,
 gboolean
 e_tree_model_has_get_node_by_id (ETreeModel *tree_model)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), FALSE);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->has_get_node_by_id != NULL, FALSE);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->has_get_node_by_id != NULL, FALSE);
 
-	return class->has_get_node_by_id (tree_model);
+	return interface->has_get_node_by_id (tree_model);
 }
 
 /**
@@ -581,14 +541,14 @@ ETreePath
 e_tree_model_get_node_by_id (ETreeModel *tree_model,
                              const gchar *save_id)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), NULL);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->get_node_by_id != NULL, NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->get_node_by_id != NULL, NULL);
 
-	return class->get_node_by_id (tree_model, save_id);
+	return interface->get_node_by_id (tree_model, save_id);
 }
 
 /**
@@ -616,14 +576,14 @@ e_tree_model_sort_value_at (ETreeModel *tree_model,
                             ETreePath path,
                             gint col)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), NULL);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->sort_value_at != NULL, NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->sort_value_at != NULL, NULL);
 
-	return class->sort_value_at (tree_model, path, col);
+	return interface->sort_value_at (tree_model, path, col);
 }
 
 /**
@@ -650,14 +610,14 @@ e_tree_model_value_at (ETreeModel *tree_model,
                        ETreePath path,
                        gint col)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), NULL);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->value_at != NULL, NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->value_at != NULL, NULL);
 
-	return class->value_at (tree_model, path, col);
+	return interface->value_at (tree_model, path, col);
 }
 
 void
@@ -666,14 +626,14 @@ e_tree_model_set_value_at (ETreeModel *tree_model,
                            gint col,
                            gconstpointer val)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_if_fail (E_IS_TREE_MODEL (tree_model));
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_if_fail (class->set_value_at != NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_if_fail (interface->set_value_at != NULL);
 
-	class->set_value_at (tree_model, path, col, val);
+	interface->set_value_at (tree_model, path, col, val);
 }
 
 /**
@@ -690,14 +650,14 @@ e_tree_model_node_is_editable (ETreeModel *tree_model,
                                ETreePath path,
                                gint col)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), FALSE);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->is_editable != NULL, FALSE);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->is_editable != NULL, FALSE);
 
-	return class->is_editable (tree_model, path, col);
+	return interface->is_editable (tree_model, path, col);
 }
 
 /**
@@ -714,14 +674,14 @@ e_tree_model_duplicate_value (ETreeModel *tree_model,
                               gint col,
                               gconstpointer value)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), NULL);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->duplicate_value != NULL, NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->duplicate_value != NULL, NULL);
 
-	return class->duplicate_value (tree_model, col, value);
+	return interface->duplicate_value (tree_model, col, value);
 }
 
 /**
@@ -738,14 +698,14 @@ e_tree_model_free_value (ETreeModel *tree_model,
                          gint col,
                          gpointer value)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_if_fail (E_IS_TREE_MODEL (tree_model));
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_if_fail (class->free_value != NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_if_fail (interface->free_value != NULL);
 
-	class->free_value (tree_model, col, value);
+	interface->free_value (tree_model, col, value);
 }
 
 /**
@@ -761,14 +721,14 @@ gpointer
 e_tree_model_initialize_value (ETreeModel *tree_model,
                                gint col)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), NULL);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->initialize_value != NULL, NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->initialize_value != NULL, NULL);
 
-	return class->initialize_value (tree_model, col);
+	return interface->initialize_value (tree_model, col);
 }
 
 /**
@@ -785,14 +745,14 @@ e_tree_model_value_is_empty (ETreeModel *tree_model,
                              gint col,
                              gconstpointer value)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), TRUE);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->value_is_empty != NULL, TRUE);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->value_is_empty != NULL, TRUE);
 
-	return class->value_is_empty (tree_model, col, value);
+	return interface->value_is_empty (tree_model, col, value);
 }
 
 /**
@@ -809,14 +769,14 @@ e_tree_model_value_to_string (ETreeModel *tree_model,
                               gint col,
                               gconstpointer value)
 {
-	ETreeModelClass *class;
+	ETreeModelInterface *interface;
 
 	g_return_val_if_fail (E_IS_TREE_MODEL (tree_model), NULL);
 
-	class = E_TREE_MODEL_GET_CLASS (tree_model);
-	g_return_val_if_fail (class->value_to_string != NULL, NULL);
+	interface = E_TREE_MODEL_GET_INTERFACE (tree_model);
+	g_return_val_if_fail (interface->value_to_string != NULL, NULL);
 
-	return class->value_to_string (tree_model, col, value);
+	return interface->value_to_string (tree_model, col, value);
 }
 
 /**
diff --git a/e-util/e-tree-model.h b/e-util/e-tree-model.h
index 431f93e2a2..bdbf64ce1b 100644
--- a/e-util/e-tree-model.h
+++ b/e-util/e-tree-model.h
@@ -1,4 +1,5 @@
 /*
+ * e-tree-model.h
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -13,13 +14,6 @@
  * You should have received a copy of the GNU Lesser General Public
  * License along with the program; if not, see <http://www.gnu.org/licenses/>
  *
- *
- * Authors:
- *		Chris Lahey <clahey@ximian.com>
- *		Chris Toshok <toshok@ximian.com>
- *
- * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
- *
  */
 
 #if !defined (__E_UTIL_H_INSIDE__) && !defined (LIBEUTIL_COMPILATION)
@@ -37,40 +31,27 @@
 #define E_TREE_MODEL(obj) \
 	(G_TYPE_CHECK_INSTANCE_CAST \
 	((obj), E_TYPE_TREE_MODEL, ETreeModel))
-#define E_TREE_MODEL_CLASS(cls) \
-	(G_TYPE_CHECK_CLASS_CAST \
-	((cls), E_TYPE_TREE_MODEL, ETreeModelClass))
 #define E_IS_TREE_MODEL(obj) \
 	(G_TYPE_CHECK_INSTANCE_TYPE \
 	((obj), E_TYPE_TREE_MODEL))
-#define E_IS_TREE_MODEL_CLASS(cls) \
-	(G_TYPE_CHECK_CLASS_TYPE \
-	((cls), E_TYPE_TREE_MODEL))
-#define E_TREE_MODEL_GET_CLASS(obj) \
-	(G_TYPE_INSTANCE_GET_CLASS \
-	((obj), E_TYPE_TREE_MODEL, ETreeModelClass))
+#define E_TREE_MODEL_GET_INTERFACE(obj) \
+	(G_TYPE_INSTANCE_GET_INTERFACE \
+	((obj), E_TYPE_TREE_MODEL, ETreeModelInterface))
 
 G_BEGIN_DECLS
 
 typedef gpointer ETreePath;
 
 typedef struct _ETreeModel ETreeModel;
-typedef struct _ETreeModelClass ETreeModelClass;
+typedef struct _ETreeModelInterface ETreeModelInterface;
 
 typedef gboolean	(*ETreePathFunc)	(ETreeModel *tree_model,
 						 ETreePath path,
 						 gpointer data);
 
-struct _ETreeModel {
-	GObject parent;
-};
+struct _ETreeModelInterface {
+	GTypeInterface parent_class;
 
-struct _ETreeModelClass {
-	GObjectClass parent_class;
-
-	/*
-	 * Virtual methods
-	 */
 	ETreePath	(*get_root)		(ETreeModel *tree_model);
 
 	ETreePath	(*get_parent)		(ETreeModel *tree_model,
diff --git a/e-util/e-util.h b/e-util/e-util.h
index 40a0e14da3..c21add21dd 100644
--- a/e-util/e-util.h
+++ b/e-util/e-util.h
@@ -209,8 +209,6 @@
 #include <e-util/e-text-model.h>
 #include <e-util/e-text.h>
 #include <e-util/e-timezone-dialog.h>
-#include <e-util/e-tree-memory-callbacks.h>
-#include <e-util/e-tree-memory.h>
 #include <e-util/e-tree-model-generator.h>
 #include <e-util/e-tree-model.h>
 #include <e-util/e-tree-selection-model.h>