Properties are supported by the GObject library. To use it, you should override the set_property() and get_property() function in GObjectClass:
NOTE: PLEASE READ ALL COMMENT CAREFULLY.
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enum { PROP_0, PROP_BASE_ID, PROP_BASE_NAME }; static void fake_base_set_property(GObject *object, guint property_id, const GValue *value, GParamSpec *pspec) { FakeBase *self = FAKE_BASE(object); switch (property_id) { case PROP_BASE_ID: self->priv->id = g_value_get_int(value); break; case PROP_BASE_NAME: g_free(self->priv->name); self->priv->name = g_value_dup_string(value); break; default: /* We don't have any other property... */ G_OBJECT_WARN_INVALID_PROPERTY_ID(object, property_id, pspec); break; } } static void fake_base_get_property(GObject *object, guint property_id, GValue *value, GParamSpec *pspec) { FakeBase *self = FAKE_BASE(object); switch (property_id) { case PROP_BASE_ID: g_value_set_int(value, self->priv->id); break; case PROP_BASE_NAME: g_value_set_string(value, self->priv->name); break; default: /* We don't have any other property... */ G_OBJECT_WARN_INVALID_PROPERTY_ID(object, property_id, pspec); break; } } static void fake_base_class_init(FakeBaseClass *klass, gpointer data) { // ... /* properties */ GObjectClass *gobject_klass = G_OBJECT_CLASS(klass); gobject_klass->set_property = fake_base_set_property; gobject_klass->get_property = fake_base_get_property; GParamSpec *pspec; pspec = g_param_spec_int("base-id", "Base ID", "Set/Get Base ID", -1000, 1000, 0, G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE); g_object_class_install_property(gobject_klass, PROP_BASE_ID, pspec); pspec = g_param_spec_string("base-name", "Base Name", "Set/Get Base Name ", NULL, G_PARAM_READWRITE); g_object_class_install_property(gobject_klass, PROP_BASE_NAME, pspec); // ... } |
All APIs are clear and easy to use, please refer to the official document. Last but not least, properties can be inherited by derived classes. Here’s my test code:
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int main() { // ... /* Base object */ FakeBase *base = (FakeBase *)g_object_new(FAKE_TYPE_BASE, "base-id", 111, NULL); GValue base_name = { 0 }; g_value_init(&base_name, G_TYPE_STRING); g_value_set_static_string(&base_name, "aaa"); g_object_set_property(G_OBJECT(base), "base-name", &base_name); g_value_unset(&base_name); /* Derived object */ FakeDerived *derived = (FakeDerived *)g_object_new( FAKE_TYPE_DERIVED, "base-id", 222, "derived-age", 333, NULL); g_object_set(derived, "base-name", "bbb", "derived-hash", "ccc", NULL); // ... } |
As you see, we can get/set properties one by one or using a parameter list.
All source code is available in my skydrive: http://cid-481cbe104492a3af.office.live.com/browse.aspx/share/dev/TestOO. In the TestGObject-{date}.zip/TestGObject5 folder.