Demonstrate extending the EExtension API.

Introduce e_extensible_list_extensions(), which provides extensible
objects access to their own extensions, or a subset of them.

Convert EShellBackend to an abstract EExtension subtype.  EShell will
load its extensions with e_extensible_load_extensions(), and then obtain
a list of EShellBackend extensions as follows:

    shell_backends = e_extensible_list_extensions (
            E_EXTENSIBLE (shell), E_TYPE_SHELL_BACKEND);

Because EShellBackend is abstract, its GType is skipped while traversing
the GType hierarchy to find EShell extensions.

1 files changed, 3 insertions, 2 deletions

diff --git a/shell/e-shell-backend.h b/shell/e-shell-backend.h
index df4abc8104..055a2a3322 100644
--- a/shell/e-shell-backend.h
+++ b/shell/e-shell-backend.h
@@ -24,6 +24,7 @@
 
 #include <shell/e-shell-common.h>
 #include <e-util/e-activity.h>
+#include <e-util/e-extension.h>
 
 /* Standard GObject macros */
 #define E_TYPE_SHELL_BACKEND \
@@ -60,7 +61,7 @@ typedef struct _EShellBackendPrivate EShellBackendPrivate;
  * functions below.
  **/
 struct _EShellBackend {
-	GObject parent;
+	EExtension parent;
 	EShellBackendPrivate *priv;
 };
 
@@ -94,7 +95,7 @@ struct _EShellBackend {
  * #EShellBackendClass contains a number of important settings for subclasses.
  **/
 struct _EShellBackendClass {
-	GObjectClass parent_class;
+	EExtensionClass parent_class;
 
 	GType shell_view_type;