diff options
Diffstat (limited to 'e-util/e-extension.c')
| -rw-r--r-- | e-util/e-extension.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/e-util/e-extension.c b/e-util/e-extension.c new file mode 100644 index 0000000000..05687b64ba --- /dev/null +++ b/e-util/e-extension.c @@ -0,0 +1,160 @@ +/* + * e-extension.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/> + * + */ + +#include "e-extension.h" + +#define E_EXTENSION_GET_PRIVATE(obj) \ + (G_TYPE_INSTANCE_GET_PRIVATE \ + ((obj), E_TYPE_EXTENSION, EExtensionPrivate)) + +struct _EExtensionPrivate { + gpointer extensible; /* weak pointer */ +}; + +enum { + PROP_0, + PROP_EXTENSIBLE +}; + +G_DEFINE_ABSTRACT_TYPE (EExtension, e_extension, G_TYPE_OBJECT) + +static void +extension_set_extensible (EExtension *extension, + EExtensible *extensible) +{ + EExtensionClass *class; + GType extensible_type; + + g_return_if_fail (E_IS_EXTENSIBLE (extensible)); + g_return_if_fail (extension->priv->extensible == NULL); + + class = E_EXTENSION_GET_CLASS (extension); + extensible_type = G_OBJECT_TYPE (extensible); + + /* Verify the EExtensible object is the type we want. */ + if (!g_type_is_a (extensible_type, class->extensible_type)) { + g_warning ("%s is meant to extend %s but was given an %s", + G_OBJECT_TYPE_NAME (extension), + g_type_name (class->extensible_type), + g_type_name (extensible_type)); + return; + } + + extension->priv->extensible = extensible; + + g_object_add_weak_pointer ( + G_OBJECT (extensible), &extension->priv->extensible); +} + +static void +extension_set_property (GObject *object, + guint property_id, + const GValue *value, + GParamSpec *pspec) +{ + switch (property_id) { + case PROP_EXTENSIBLE: + extension_set_extensible ( + E_EXTENSION (object), + g_value_get_object (value)); + return; + } + + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec); +} + +static void +extension_get_property (GObject *object, + guint property_id, + GValue *value, + GParamSpec *pspec) +{ + switch (property_id) { + case PROP_EXTENSIBLE: + g_value_set_object ( + value, e_extension_get_extensible ( + E_EXTENSION (object))); + return; + } + + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec); +} + +static void +extension_constructed (GObject *object) +{ + /* This allows subclasses to chain up safely since GObject + * does not implement this method, and we might want to do + * something here in the future. */ +} + +static void +extension_dispose (GObject *object) +{ + EExtensionPrivate *priv; + + priv = E_EXTENSION_GET_PRIVATE (object); + + if (priv->extensible != NULL) { + g_object_remove_weak_pointer ( + G_OBJECT (priv->extensible), &priv->extensible); + priv->extensible = NULL; + } + + /* Chain up to parent's dispose() method. */ + G_OBJECT_CLASS (e_extension_parent_class)->dispose (object); +} + +static void +e_extension_class_init (EExtensionClass *class) +{ + GObjectClass *object_class; + + g_type_class_add_private (class, sizeof (EExtensionPrivate)); + + object_class = G_OBJECT_CLASS (class); + object_class->set_property = extension_set_property; + object_class->get_property = extension_get_property; + object_class->constructed = extension_constructed; + object_class->dispose = extension_dispose; + + g_object_class_install_property ( + object_class, + PROP_EXTENSIBLE, + g_param_spec_object ( + "extensible", + "Extensible Object", + "The object being extended", + E_TYPE_EXTENSIBLE, + G_PARAM_READWRITE | + G_PARAM_CONSTRUCT_ONLY)); +} + +static void +e_extension_init (EExtension *extension) +{ + extension->priv = E_EXTENSION_GET_PRIVATE (extension); +} + +EExtensible * +e_extension_get_extensible (EExtension *extension) +{ + g_return_val_if_fail (E_IS_EXTENSION (extension), NULL); + + return E_EXTENSIBLE (extension->priv->extensible); +} |