[calls] manager: Implement message source interface

[Evangelos Ribeiro Tzaras <devrtz src gnome org>]

commit 6d877fd9d3f6abbe52fd223edd2c8bc71464121b
Author: Evangelos Ribeiro Tzaras <devrtz fortysixandtwo eu>
Date:   Tue Dec 28 14:43:54 2021 +0100

    manager: Implement message source interface
    
    This allows the user interface to pick up messages by having them propagate
    from the managed providers, origins, calls, etc.

 src/calls-manager.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)
---
diff --git a/src/calls-manager.c b/src/calls-manager.c
index 461429c2..2a029da3 100644
--- a/src/calls-manager.c
+++ b/src/calls-manager.c
@@ -30,6 +30,7 @@
 #include "calls-application.h"
 #include "calls-contacts-provider.h"
 #include "calls-manager.h"
+#include "calls-message-source.h"
 #include "calls-provider.h"
 #include "calls-settings.h"
 #include "calls-ussd.h"
@@ -60,7 +61,14 @@ struct _CallsManager
   CallsSettings *settings;
 };
 
-G_DEFINE_TYPE (CallsManager, calls_manager, G_TYPE_OBJECT);
+static void
+calls_manager_message_source_interface_init (CallsMessageSourceInterface *iface)
+{
+}
+
+G_DEFINE_TYPE_WITH_CODE (CallsManager, calls_manager, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (CALLS_TYPE_MESSAGE_SOURCE,
+                                                calls_manager_message_source_interface_init))
 
 enum {
   PROP_0,