[d-feet: 5/7] DFeetApp: add --version

[Thomas Bechtold <toabctl src gnome org>]

commit 5e745a2faa5f2780e4ebcd42ea0105bdd9c8bd57
Author: Marc-André Lureau <marcandre lureau redhat com>
Date:   Thu Mar 26 23:17:07 2020 +0100

    DFeetApp: add --version
    
    Signed-off-by: Marc-André Lureau <marcandre lureau redhat com>

 src/dfeet/application.py | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)
---
diff --git a/src/dfeet/application.py b/src/dfeet/application.py
index 920f67b..7f4f44a 100644
--- a/src/dfeet/application.py
+++ b/src/dfeet/application.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 
 from __future__ import print_function
-from gi.repository import Gtk, Gio, GObject, Gdk
+from gi.repository import Gtk, Gio, GObject, Gdk, GLib
 from dfeet.window import DFeetWindow
 import gettext
 import os
@@ -9,6 +9,20 @@ import os
 _ = gettext.gettext
 
 
+def make_option(long_name, short_name=None, flags=0, arg=GLib.OptionArg.NONE,
+                arg_data=None, description=None, arg_description=None):
+    # surely something like this should exist inside PyGObject itself?!
+    option = GLib.OptionEntry()
+    option.long_name = long_name.lstrip('-')
+    option.short_name = 0 if not short_name else short_name.lstrip('-')
+    option.flags = flags
+    option.arg = arg
+    option.arg_data = arg_data
+    option.description = description
+    option.arg_description = arg_description
+    return option
+
+
 class DFeetApp(Gtk.Application):
 
     def __init__(self, package, version, data_dir):
@@ -17,6 +31,16 @@ class DFeetApp(Gtk.Application):
         self.data_dir = data_dir
         Gtk.Application.__init__(self, application_id="org.gnome.dfeet",
                                  flags=Gio.ApplicationFlags.FLAGS_NONE)
+        self.add_main_option_entries([
+            make_option("--version", description=_("Show version number and exit")),
+        ])
+
+    def do_handle_local_options(self, options):
+        self.options = options
+        if options.contains("version"):
+            print(_("D-Feet version: {}").format(self.version))
+            return 0
+        return -1
 
     # Note that the function in C activate() becomes do_activate() in Python
     def do_activate(self):