Convert EAttachmentHandler to an EExtension.

EAttachmentHandler predates EExtension, so this is really just a code
cleanup to use the extension framework.  But this also demonstrates that
extensions can target interfaces as well as instantiable types, since
EAttachmentView is an interface.

What's also nice is EAttachmentView no longer has to directly interact
with attachment handlers.  Instead of EAttachmentView having to query
each attachment handler for drag-and-drop info, each handler now pushes
its own drag-and-drop info to its EAttachmentView during initialization.

1 files changed, 30 insertions, 84 deletions

diff --git a/widgets/misc/e-attachment-handler.c b/widgets/misc/e-attachment-handler.c
index 947ae666d9..0b9c057b65 100644
--- a/widgets/misc/e-attachment-handler.c
+++ b/widgets/misc/e-attachment-handler.c
@@ -26,113 +26,53 @@
 	((obj), E_TYPE_ATTACHMENT_HANDLER, EAttachmentHandlerPrivate))
 
 struct _EAttachmentHandlerPrivate {
-	gpointer view;  /* weak pointer */
-};
-
-enum {
-	PROP_0,
-	PROP_VIEW
+	gpointer placeholder;
 };
 
 G_DEFINE_TYPE (
 	EAttachmentHandler,
 	e_attachment_handler,
-	G_TYPE_OBJECT)
-
-static void
-attachment_handler_set_view (EAttachmentHandler *handler,
-                             EAttachmentView *view)
-{
-	g_return_if_fail (handler->priv->view == NULL);
-
-	handler->priv->view = view;
-
-	g_object_add_weak_pointer (
-		G_OBJECT (view), &handler->priv->view);
-}
-
-static void
-attachment_handler_set_property (GObject *object,
-                                 guint property_id,
-                                 const GValue *value,
-                                 GParamSpec *pspec)
-{
-	switch (property_id) {
-		case PROP_VIEW:
-			attachment_handler_set_view (
-				E_ATTACHMENT_HANDLER (object),
-				g_value_get_object (value));
-			return;
-	}
-
-	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
-}
-
-static void
-attachment_handler_get_property (GObject *object,
-                                 guint property_id,
-                                 GValue *value,
-                                 GParamSpec *pspec)
-{
-	switch (property_id) {
-		case PROP_VIEW:
-			g_value_set_object (
-				value, e_attachment_handler_get_view (
-				E_ATTACHMENT_HANDLER (object)));
-			return;
-	}
-
-	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
-}
+	E_TYPE_EXTENSION)
 
 static void
 attachment_handler_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. */
-}
+	EAttachmentView *view;
+	EAttachmentHandler *handler;
+	GdkDragAction drag_actions;
+	GtkTargetList *target_list;
+	const GtkTargetEntry *targets;
+	guint n_targets;
 
-static void
-attachment_handler_dispose (GObject *object)
-{
-	EAttachmentHandlerPrivate *priv;
+	handler = E_ATTACHMENT_HANDLER (object);
+	drag_actions = e_attachment_handler_get_drag_actions (handler);
+	targets = e_attachment_handler_get_target_table (handler, &n_targets);
+
+	view = e_attachment_handler_get_view (handler);
 
-	priv = E_ATTACHMENT_HANDLER_GET_PRIVATE (object);
+	target_list = e_attachment_view_get_target_list (view);
+	gtk_target_list_add_table (target_list, targets, n_targets);
 
-	if (priv->view != NULL) {
-		g_object_remove_weak_pointer (
-			G_OBJECT (priv->view), &priv->view);
-		priv->view = NULL;
-	}
+	e_attachment_view_add_drag_actions (view, drag_actions);
 
-	/* Chain up to parent's dispose() method. */
-	G_OBJECT_CLASS (e_attachment_handler_parent_class)->dispose (object);
+	/* Chain up to parent's constructed() method. */
+	G_OBJECT_CLASS (e_attachment_handler_parent_class)->
+		constructed (object);
 }
 
 static void
 e_attachment_handler_class_init (EAttachmentHandlerClass *class)
 {
 	GObjectClass *object_class;
+	EExtensionClass *extension_class;
 
 	g_type_class_add_private (class, sizeof (EAttachmentHandlerPrivate));
 
 	object_class = G_OBJECT_CLASS (class);
-	object_class->set_property = attachment_handler_set_property;
-	object_class->get_property = attachment_handler_get_property;
 	object_class->constructed = attachment_handler_constructed;
-	object_class->dispose = attachment_handler_dispose;
-
-	g_object_class_install_property (
-		object_class,
-		PROP_VIEW,
-		g_param_spec_object (
-			"view",
-			"View",
-			NULL,
-			E_TYPE_ATTACHMENT_VIEW,
-			G_PARAM_READWRITE |
-			G_PARAM_CONSTRUCT_ONLY));
+
+	extension_class = E_EXTENSION_CLASS (class);
+	extension_class->extensible_type = E_TYPE_ATTACHMENT_VIEW;
 }
 
 static void
@@ -144,9 +84,15 @@ e_attachment_handler_init (EAttachmentHandler *handler)
 EAttachmentView *
 e_attachment_handler_get_view (EAttachmentHandler *handler)
 {
+	EExtensible *extensible;
+
+	/* This is purely a convenience function. */
+
 	g_return_val_if_fail (E_IS_ATTACHMENT_HANDLER (handler), NULL);
 
-	return E_ATTACHMENT_VIEW (handler->priv->view);
+	extensible = e_extension_get_extensible (E_EXTENSION (handler));
+
+	return E_ATTACHMENT_VIEW (extensible);
 }
 
 GdkDragAction