Add command line argument parsing with '-c' option

Only print satellite info to standard output if -c / --console-output
flag is given.

satellite/application.py

@@ -1,4 +1,5 @@
 #!/usr/bin/env python3
+import argparse
 import gi
 import gpxpy
 import os
@@ -37,6 +38,15 @@ class SatelliteApp(Gtk.Application):
             self, *args, application_id="page.codeberg.tpikonen.satellite",
             flags=Gio.ApplicationFlags.FLAGS_NONE, **kwargs)
         Handy.init()
+
+        desc = "Displays navigation satellite data and saves GPX tracks"
+        parser = argparse.ArgumentParser(description=desc)
+        parser.add_argument(
+            '-c', '--console-output', dest='console_output',
+            action='store_true', default=False,
+            help='Output satellite data to console')
+        self.args = parser.parse_args()
+
         GLib.unix_signal_add(GLib.PRIORITY_DEFAULT, signal.SIGINT,
                              self.sigint_handler)
 
@@ -363,7 +373,8 @@ class SatelliteApp(Gtk.Application):
                 value = fun(data[key])
             descs.append(desc)
             vals.append(value)
-            print(f"{desc}: {value}")
+            if self.args.console_output:
+                print(f"{desc}: {value}")
 
         if self.dataframe.rows != len(descs):
             self.dataframe.set_rowtitles(descs)
@@ -491,7 +502,8 @@ class SatelliteApp(Gtk.Application):
         data["updateage"] = ((time.time() - self.last_update)
                              if self.last_update else None)
         barchart = self.format_satellite_data(data)
-        print(barchart)
+        if self.args.console_output:
+            print(barchart)
         self.infolabel.set_markup("<tt>" + barchart + "</tt>")
         self.set_values(data)
         mode = data["mode"]