utils: Add macro for getting default application

This will be needed as a replacement for the removal of the
"context" property on every object.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/702>

src/utils/gcal-utils.h

@@ -19,6 +19,7 @@
 #ifndef __GCAL_UTILS_H__
 #define __GCAL_UTILS_H__
 
+#include "gcal-application.h"
 #include "gcal-date-time-utils.h"
 #include "gcal-manager.h"
 
@@ -31,6 +32,8 @@
 #define MINUTES_PER_DAY 1440
 #define MAX_MINUTES     (N_WEEKDAYS * MINUTES_PER_DAY)
 
+#define GCAL_DEFAULT_APPLICATION GCAL_APPLICATION (g_application_get_default ())
+
 #define gcal_clear_timeout(pp) { if (pp && *pp) { g_source_remove (*pp); *pp = 0; } }
 #define gcal_clear_signal_handler(pp,instance) { if (pp && *pp > 0) { g_signal_handler_disconnect (instance, *pp); *pp = 0; } }