Index: e-util/e-binding.h
===================================================================
--- e-util/e-binding.h	(revision 0)
+++ e-util/e-binding.h	(revision 0)
@@ -0,0 +1,118 @@
+/*
+ * e-binding.h
+ *
+ * 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/>  
+ *
+ *
+ * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
+ *
+ */
+
+/* This is a direct rip-off of Xfce's excellent ExoBinding API,
+ * which binds two GObject properties together.  ExoBinding was
+ * written by Benedikt Meurer <benny@xfce.org>. */
+
+#ifndef E_BINDING_H
+#define E_BINDING_H
+
+#include <gdk/gdk.h>
+
+G_BEGIN_DECLS
+
+typedef struct _EBinding EBinding;
+typedef struct _EBindingBase EBindingBase;
+typedef struct _EBindingLink EBindingLink;
+typedef struct _EMutualBinding EMutualBinding;
+
+typedef gboolean	(*EBindingTransform)	(const GValue *src_value,
+						 GValue *dst_value,
+						 gpointer user_data);
+
+struct _EBindingBase {
+	GDestroyNotify destroy;
+};
+
+struct _EBindingLink {
+	GObject *dst_object;
+	GParamSpec *dst_pspec;
+	gulong dst_handler; /* only set for mutual bindings */
+	gulong handler;
+	EBindingTransform transform;
+	gpointer user_data;
+};
+
+struct _EBinding {
+	/*< private >*/
+	GObject *src_object;
+	EBindingBase base;
+	EBindingLink link;
+};
+
+struct _EMutualBinding {
+	/*< private >*/
+	EBindingBase  base;
+	EBindingLink  direct;
+	EBindingLink  reverse;
+};
+
+EBinding *	e_binding_new			(GObject *src_object,
+						 const gchar *src_property,
+						 GObject *dst_object,
+						 const gchar *dst_property);
+EBinding *	e_binding_new_full		(GObject *src_object,
+						 const gchar *src_property,
+						 GObject *dst_object,
+						 const gchar *dst_property,
+						 EBindingTransform transform,
+						 GDestroyNotify destroy_notify,
+						 gpointer user_data);
+EBinding *	e_binding_new_with_negation	(GObject *src_object,
+						 const gchar *src_property,
+						 GObject *dst_object,
+						 const gchar *dst_property);
+void		e_binding_unbind		(EBinding *binding);
+
+EMutualBinding *e_mutual_binding_new		(GObject *object1,
+						 const gchar *property1,
+						 GObject *object2,
+						 const gchar *property2);
+EMutualBinding *e_mutual_binding_new_full	(GObject *object1,
+						 const gchar *property1,
+						 GObject *object2,
+						 const gchar *property2,
+						 EBindingTransform transform,
+						 EBindingTransform reverse_transform,
+						 GDestroyNotify destroy_notify,
+						 gpointer user_data);
+EMutualBinding *e_mutual_binding_new_with_negation
+						(GObject *object1,
+						 const gchar *property1,
+						 GObject *object2,
+						 const gchar *property2);
+void		e_mutual_binding_unbind		(EMutualBinding *binding);
+
+
+/* Useful transformation functions */
+gboolean	e_binding_transform_color_to_string
+						(const GValue *src_value,
+						 GValue *dst_value,
+						 gpointer user_data);
+gboolean	e_binding_transform_string_to_color
+						(const GValue *src_value,
+						 GValue *dst_value,
+						 gpointer user_data);
+
+G_END_DECLS
+
+#endif /* E_BINDING_H */
Index: e-util/Makefile.am
===================================================================
--- e-util/Makefile.am	(revision 37491)
+++ e-util/Makefile.am	(working copy)
@@ -41,6 +41,7 @@ privsolib_LTLIBRARIES = libeutil.la libe
 
 eutilinclude_HEADERS = 				\
 	e-bconf-map.h				\
+	e-binding.h				\
 	e-categories-config.h			\
 	e-config.h				\
 	e-config-listener.h			\
@@ -83,6 +84,7 @@ libeutil_la_SOURCES =				\
 	$(eutilinclude_HEADERS)			\
 	e-util-marshal.c			\
 	e-bconf-map.c				\
+	e-binding.c				\
 	e-categories-config.c			\
 	e-config.c				\
 	e-config-listener.c			\
Index: e-util/e-binding.c
===================================================================
--- e-util/e-binding.c	(revision 0)
+++ e-util/e-binding.c	(revision 0)
@@ -0,0 +1,536 @@
+/*
+ * e-binding.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
+ * 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/>  
+ *
+ *
+ * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "e-binding.h"
+
+static gboolean
+e_binding_transform_negate (const GValue *src_value,
+                            GValue *dst_value)
+{
+	if (!g_value_transform (src_value, dst_value))
+		return FALSE;
+
+	g_value_set_boolean (dst_value, !g_value_get_boolean (dst_value));
+
+	return TRUE;
+}
+
+static void
+e_bind_properties_transfer (GObject *src_object,
+                            GParamSpec *src_pspec,
+                            GObject *dst_object,
+                            GParamSpec *dst_pspec,
+                            EBindingTransform  transform,
+                            gpointer user_data)
+{
+	const gchar *src_name;
+	const gchar *dst_name;
+	gboolean result;
+	GValue src_value = { 0, };
+	GValue dst_value = { 0, };
+
+	src_name = g_param_spec_get_name (src_pspec);
+	dst_name = g_param_spec_get_name (dst_pspec);
+
+	g_value_init (&src_value, G_PARAM_SPEC_VALUE_TYPE (src_pspec));
+	g_object_get_property (src_object, src_name, &src_value);
+
+	g_value_init (&dst_value, G_PARAM_SPEC_VALUE_TYPE (dst_pspec));
+	result = (*transform) (&src_value, &dst_value, user_data);
+
+	g_value_unset (&src_value);
+
+	g_return_if_fail (result);
+
+	g_param_value_validate (dst_pspec, &dst_value);
+	g_object_set_property (dst_object, dst_name, &dst_value);
+	g_value_unset (&dst_value);
+}
+
+static void
+e_bind_properties_notify (GObject *src_object,
+                          GParamSpec *src_pspec,
+                          gpointer data)
+{
+	EBindingLink *link = data;
+
+	/* Block the destination handler for mutual bindings,
+	 * so we don't recurse here. */
+	if (link->dst_handler != 0)
+		g_signal_handler_block (link->dst_object, link->dst_handler);
+
+	e_bind_properties_transfer (
+		src_object, src_pspec,
+		link->dst_object, link->dst_pspec,
+		link->transform, link->user_data);
+
+	/* Unblock destination handler. */
+	if (link->dst_handler != 0)
+		g_signal_handler_unblock (link->dst_object, link->dst_handler);
+}
+
+static void
+e_binding_on_dst_object_destroy (gpointer  data,
+                                 GObject  *object)
+{
+	EBinding *binding = data;
+
+	binding->link.dst_object = NULL;
+
+	/* Calls e_binding_on_disconnect() */
+	g_signal_handler_disconnect (
+		binding->src_object, binding->link.handler);
+}
+
+static void
+e_binding_on_disconnect (gpointer data,
+                         GClosure *closure)
+{
+	EBindingLink *link = data;
+	EBinding *binding;
+
+	binding = (EBinding *)
+		(((gchar *) link) - G_STRUCT_OFFSET (EBinding, link));
+
+	if (binding->base.destroy != NULL)
+		binding->base.destroy (link->user_data);
+
+	if (link->dst_object != NULL)
+		g_object_weak_unref (
+			link->dst_object,
+			e_binding_on_dst_object_destroy, binding);
+
+	g_slice_free (EBinding, binding);
+}
+
+/* Recursively calls e_mutual_binding_on_disconnect_object2() */
+static void
+e_mutual_binding_on_disconnect_object1 (gpointer data,
+                                        GClosure *closure)
+{
+	EMutualBinding *binding;
+	EBindingLink *link = data;
+	GObject *object2;
+
+	binding = (EMutualBinding *)
+		(((gchar *) link) - G_STRUCT_OFFSET (EMutualBinding, direct));
+	binding->reverse.dst_object = NULL;
+
+	object2 = binding->direct.dst_object;
+	if (object2 != NULL) {
+		if (binding->base.destroy != NULL)
+			binding->base.destroy (binding->direct.user_data);
+		binding->direct.dst_object = NULL;
+		g_signal_handler_disconnect (object2, binding->reverse.handler);
+		g_slice_free (EMutualBinding, binding);
+	}
+}
+
+/* Recursively calls e_mutual_binding_on_disconnect_object1() */
+static void
+e_mutual_binding_on_disconnect_object2 (gpointer data,
+                                        GClosure *closure)
+{
+	EMutualBinding *binding;
+	EBindingLink *link = data;
+	GObject *object1;
+
+	binding = (EMutualBinding *)
+		(((gchar *) link) - G_STRUCT_OFFSET (EMutualBinding, reverse));
+	binding->direct.dst_object = NULL;
+
+	object1 = binding->reverse.dst_object;
+	if (object1 != NULL) {
+		binding->reverse.dst_object = NULL;
+		g_signal_handler_disconnect (object1, binding->direct.handler);
+	}
+}
+
+static void
+e_binding_link_init (EBindingLink *link,
+                     GObject *src_object,
+                     const gchar *src_property,
+                     GObject *dst_object,
+                     GParamSpec *dst_pspec,
+                     EBindingTransform transform,
+                     GClosureNotify destroy_notify,
+                     gpointer user_data)
+{
+	gchar *signal_name;
+
+	link->dst_object = dst_object;
+	link->dst_pspec = dst_pspec;
+	link->dst_handler = 0;
+	link->transform = transform;
+	link->user_data = user_data;
+
+	signal_name = g_strconcat ("notify::", src_property, NULL);
+	link->handler = g_signal_connect_data (
+		src_object, signal_name,
+		G_CALLBACK (e_bind_properties_notify),
+		link, destroy_notify, 0);
+	g_free (signal_name);
+}
+
+/**
+ * e_binding_new:
+ * @src_object: The source #GObject.
+ * @src_property: The name of the property to bind from.
+ * @dst_object: The destination #GObject.
+ * @dst_property: The name of the property to bind to.
+ *
+ * One-way binds @src_property in @src_object to @dst_property
+ * in @dst_object.
+ *
+ * Before binding the value of @dst_property is set to the
+ * value of @src_property.
+ *
+ * Returns: The descriptor of the binding. It is automatically
+ *          removed if one of the objects is finalized.
+ **/
+EBinding *
+e_binding_new (GObject *src_object,
+               const gchar *src_property,
+               GObject *dst_object,
+               const gchar *dst_property)
+{
+	return e_binding_new_full (
+		src_object, src_property,
+		dst_object, dst_property,
+		NULL, NULL, NULL);
+}
+
+/**
+ * e_binding_new_full:
+ * @src_object: The source #GObject.
+ * @src_property: The name of the property to bind from.
+ * @dst_object: The destination #GObject.
+ * @dst_property: The name of the property to bind to.
+ * @transform: Transformation function or %NULL.
+ * @destroy_notify: Callback function that is called on
+ *                  disconnection with @user_data or %NULL.
+ * @user_data: User data associated with the binding.
+ *
+ * One-way binds @src_property in @src_object to @dst_property
+ * in @dst_object.
+ *
+ * Before binding the value of @dst_property is set to the
+ * value of @src_property.
+ *
+ * Returns: The descriptor of the binding. It is automatically
+ *          removed if one of the objects is finalized.
+ **/
+EBinding *
+e_binding_new_full (GObject *src_object,
+                    const gchar *src_property,
+                    GObject *dst_object,
+                    const gchar *dst_property,
+                    EBindingTransform transform,
+                    GDestroyNotify destroy_notify,
+                    gpointer user_data)
+{
+	EBinding *binding;
+	GParamSpec *src_pspec;
+	GParamSpec *dst_pspec;
+
+	g_return_val_if_fail (G_IS_OBJECT (src_object), NULL);
+	g_return_val_if_fail (G_IS_OBJECT (dst_object), NULL);
+
+	src_pspec = g_object_class_find_property (
+		G_OBJECT_GET_CLASS (src_object), src_property);
+	dst_pspec = g_object_class_find_property (
+		G_OBJECT_GET_CLASS (dst_object), dst_property);
+
+	if (transform == NULL)
+		transform = (EBindingTransform) g_value_transform;
+
+	e_bind_properties_transfer (
+		src_object, src_pspec,
+		dst_object, dst_pspec,
+		transform, user_data);
+
+	binding = g_slice_new (EBinding);
+	binding->src_object = src_object;
+	binding->base.destroy = destroy_notify;
+
+	e_binding_link_init (
+		&binding->link, src_object, src_property, dst_object,
+		dst_pspec, transform, e_binding_on_disconnect, user_data);
+
+	g_object_weak_ref (
+		dst_object, e_binding_on_dst_object_destroy, binding);
+
+	return binding;
+}
+
+/**
+ * e_binding_new_with_negation:
+ * @src_object: The source #GObject.
+ * @src_property: The name of the property to bind from.
+ * @dst_object: The destination #GObject.
+ * @dst_property: The name of the property to bind to.
+ *
+ * Convenience function for binding with boolean negation of value.
+ *
+ * Return: The descriptor of the binding. It is automatically
+ *         removed if one of the objects is finalized.
+ **/
+EBinding *
+e_binding_new_with_negation (GObject *src_object,
+                             const gchar *src_property,
+                             GObject *dst_object,
+                             const gchar *dst_property)
+{
+	EBindingTransform transform;
+
+	transform = (EBindingTransform) e_binding_transform_negate;
+
+	return e_binding_new_full (
+		src_object, src_property,
+		dst_object, dst_property,
+		transform, NULL, NULL);
+}
+
+/**
+ * e_binding_unbind:
+ * @binding: An #EBinding to unbind.
+ *
+ * Disconnects the binding between two properties. Should be
+ * rarely used by applications.
+ *
+ * This functions also calls the @destroy_notify function that
+ * was specified when @binding was created.
+ **/
+void
+e_binding_unbind (EBinding *binding)
+{
+	g_signal_handler_disconnect (
+		binding->src_object, binding->link.handler);
+}
+
+/**
+ * e_mutual_binding_new:
+ * @object1 : The first #GObject.
+ * @property1: The first property to bind.
+ * @object2 : The second #GObject.
+ * @property2: The second property to bind.
+ *
+ * Mutually binds values of two properties.
+ *
+ * Before binding the value of @property2 is set to the value
+ * of @property1.
+ *
+ * Returns: The descriptor of the binding. It is automatically
+ *          removed if one of the objects is finalized.
+ **/
+EMutualBinding *
+e_mutual_binding_new (GObject *object1,
+                      const gchar *property1,
+                      GObject *object2,
+                      const gchar *property2)
+{
+	return e_mutual_binding_new_full (
+		object1, property1,
+		object2, property2,
+		NULL, NULL, NULL, NULL);
+}
+
+/**
+ * e_mutual_binding_new_full:
+ * @object1: The first #GObject.
+ * @property1: The first property to bind.
+ * @object2: The second #GObject.
+ * @property2: The second property to bind.
+ * @transform: Transformation function or %NULL.
+ * @reverse_transform: The inverse transformation function or %NULL.
+ * @destroy_notify: Callback function called on disconnection with
+ *                  @user_data as argument or %NULL.
+ * @user_data: User data associated with the binding.
+ *
+ * Mutually binds values of two properties.
+ *
+ * Before binding the value of @property2 is set to the value of
+ * @property1.
+ *
+ * Both @transform and @reverse_transform should simultaneously be
+ * %NULL or non-%NULL. If they are non-%NULL, they should be reverse
+ * in each other.
+ *
+ * Returns: The descriptor of the binding. It is automatically
+ *          removed if one of the objects is finalized.
+ **/
+EMutualBinding *
+e_mutual_binding_new_full (GObject *object1,
+                           const gchar *property1,
+                           GObject *object2,
+                           const gchar *property2,
+                           EBindingTransform transform,
+                           EBindingTransform reverse_transform,
+                           GDestroyNotify destroy_notify,
+                           gpointer user_data)
+{
+	EMutualBinding *binding;
+	GParamSpec *pspec1;
+	GParamSpec *pspec2;
+
+	g_return_val_if_fail (G_IS_OBJECT (object1), NULL);
+	g_return_val_if_fail (G_IS_OBJECT (object2), NULL);
+
+	pspec1 = g_object_class_find_property (
+		G_OBJECT_GET_CLASS (object1), property1);
+	pspec2 = g_object_class_find_property (
+		G_OBJECT_GET_CLASS (object2), property2);
+
+	if (transform == NULL)
+		transform = (EBindingTransform) g_value_transform;
+
+	if (reverse_transform == NULL)
+		reverse_transform = (EBindingTransform) g_value_transform;
+
+	e_bind_properties_transfer (
+		object1, pspec1, object2,
+		pspec2, transform, user_data);
+
+	binding = g_slice_new (EMutualBinding);
+	binding->base.destroy = destroy_notify;
+
+	e_binding_link_init (
+		&binding->direct,
+		object1, property1, object2, pspec2, transform,
+		e_mutual_binding_on_disconnect_object1, user_data);
+
+	e_binding_link_init (
+		&binding->reverse,
+		object2, property2, object1, pspec1, reverse_transform,
+		e_mutual_binding_on_disconnect_object2, user_data);
+
+	/* Tell each link about the reverse link for mutual bindings,
+	 * to make sure that we do not ever recurse in notify (yeah,
+	 * the GObject notify dispatching is really weird!). */
+	binding->direct.dst_handler = binding->reverse.handler;
+	binding->reverse.dst_handler = binding->direct.handler;
+
+	return binding;
+}
+
+/**
+ * e_mutual_binding_new_with_negation:
+ * @object1: The first #GObject.
+ * @property1: The first property to bind.
+ * @object2: The second #GObject.
+ * @property2: The second property to bind.
+ *
+ * Convenience function for binding with boolean negation of value.
+ *
+ * Returns: The descriptor of the binding. It is automatically removed
+ *          if one of the objects if finalized.
+ **/
+EMutualBinding*
+e_mutual_binding_new_with_negation (GObject *object1,
+                                    const gchar *property1,
+                                    GObject *object2,
+                                    const gchar *property2)
+{
+	EBindingTransform transform;
+
+	transform = (EBindingTransform) e_binding_transform_negate;
+
+	return e_mutual_binding_new_full (
+		object1, property1,
+		object2, property2,
+		transform, transform,
+		NULL, NULL);
+}
+
+/**
+ * e_mutual_binding_unbind:
+ * @binding: An #EMutualBinding to unbind.
+ *
+ * Disconnects the binding between two properties. Should be
+ * rarely used by applications.
+ *
+ * This functions also calls the @destroy_notify function that
+ * was specified when @binding was created.
+ **/
+void
+e_mutual_binding_unbind (EMutualBinding *binding)
+{
+	g_signal_handler_disconnect (
+		binding->reverse.dst_object, binding->direct.handler);
+}
+
+/**
+ * e_binding_transform_color_to_string:
+ * @src_value: a #GValue of type #GDK_TYPE_COLOR
+ * @dst_value: a #GValue of type #G_TYPE_STRING
+ * @user_data: not used
+ *
+ * Transforms a #GdkColor value to a color string specification.
+ *
+ * Returns: %TRUE always
+ **/
+gboolean
+e_binding_transform_color_to_string (const GValue *src_value,
+                                     GValue *dst_value,
+                                     gpointer user_data)
+{
+	const GdkColor *color;
+	gchar *string;
+
+	color = g_value_get_boxed (src_value);
+	string = gdk_color_to_string (color);
+	g_value_set_string (dst_value, string);
+	g_free (string);
+
+	return TRUE;
+}
+
+/**
+ * e_binding_transform_string_to_color:
+ * @src_value: a #GValue of type #G_TYPE_STRING
+ * @dst_value: a #GValue of type #GDK_TYPE_COLOR
+ * @user_data: not used
+ *
+ * Transforms a color string specification to a #GdkColor.
+ *
+ * Returns: %TRUE if color string specification was valid
+ **/
+gboolean
+e_binding_transform_string_to_color (const GValue *src_value,
+                                     GValue *dst_value,
+                                     gpointer user_data)
+{
+	GdkColor color;
+	const gchar *string;
+	gboolean success = FALSE;
+
+	string = g_value_get_string (src_value);
+	if (gdk_color_parse (string, &color)) {
+		g_value_set_boxed (dst_value, &color);
+		success = TRUE;
+	}
+
+	return success;
+}
