Be DBus-Activatable

This is useful if GTG exposes some DBus services, so that the user don't
need to keep the application open, but rather it can be started (and
exited) as needed, for example when the user is searching for some tasks
(not implemented here).

data/meson.build

@@ -21,4 +21,16 @@ i18n.merge_file(
   type: 'desktop'
 )
 
+service_config = configuration_data()
+service_config.set('APP_ID', application_id)
+service_config.set('bindir', bindir)
+
+configure_file(
+  input: rdnn_name + '.service.in',
+  output: application_id + '.service',
+  configuration: service_config,
+  install: true,
+  install_dir: dbusservicedir
+)
+
 subdir('icons')

data/org.gnome.GTG.desktop.in.in

@@ -13,3 +13,4 @@ Categories=Office;ProjectManagement;
 Keywords=Organizer;Task;Tasks;Projects;Activities;Productivity;Plan;Planning;Planner;Time;Management;Scheduling;GTD;gtg;Todo;
 MimeType=x-scheme-handler/gtg;
 StartupNotify=true
+DBusActivatable=true

data/org.gnome.GTG.service.in

@@ -0,0 +1,3 @@
+[D-BUS Service]
+Name=@APP_ID@
+Exec=@bindir@/gtg --gapplication-service

meson.build

@@ -19,6 +19,7 @@ datadir = prefix / get_option('datadir')
 
 appdatadir = datadir / 'metainfo'
 desktopdir = datadir / 'applications'
+dbusservicedir = datadir / 'dbus-1' / 'services'
 icondir = datadir / 'icons'
 pythondir = python3.get_path('purelib')
 rdnn_name = 'org.gnome.GTG'
@@ -33,6 +34,7 @@ bin_config.set('local_build', 'False')
 bin_config.set('pythondir', pythondir)
 bin_config.set('localedir', datadir / 'locale')
 bin_config.set('APP_ID', application_id)
+bin_config.set('bindir', bindir)
 
 local_config = configuration_data()
 local_config.set('local_build', 'True')