[gnome-games] steam: Support Steam in Flatpak

[Adrien Plazas <aplazas src gnome org>]

commit 441bc12da1f0d176d54fb9411ccf78e78be4b6d6
Author: Alexander Mikhaylenko <exalm7659 gmail com>
Date:   Fri Aug 10 03:10:18 2018 +0500

    steam: Support Steam in Flatpak
    
    Steam in Flatpak uses a different data directory, and has to be launched
    via "flatpak run".

 plugins/steam/src/steam-plugin.vala | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)
---
diff --git a/plugins/steam/src/steam-plugin.vala b/plugins/steam/src/steam-plugin.vala
index 383c0c02..f4f1412f 100644
--- a/plugins/steam/src/steam-plugin.vala
+++ b/plugins/steam/src/steam-plugin.vala
@@ -1,7 +1,11 @@
 // This file is part of GNOME Games. License: GPL-3.0+.
 
 private class Games.SteamPlugin : Object, Plugin {
+       private const string STEAM_APPID = "com.valvesoftware.Steam";
+       private const string STEAM_FLATPAK_DIR = "/.var/app/" + STEAM_APPID;
+
        private const string STEAM_FILE_SCHEME = "steam+file";
+       private const string FLATPAK_STEAM_FILE_SCHEME = "flatpak+steam+file";
        private const string PLATFORM_ID = "Steam";
        private const string PLATFORM_NAME = _("Steam");
 
@@ -15,16 +19,23 @@ private class Games.SteamPlugin : Object, Plugin {
                // Steam's installation path can be found in its registry.
                var home = Environment.get_home_dir ();
 
+               UriSource[] sources = {};
+
                try {
-                       var source = new SteamUriSource (home, STEAM_FILE_SCHEME);
+                       sources += new SteamUriSource (home, STEAM_FILE_SCHEME);
+               }
+               catch (Error e) {
+                       debug (e.message);
+               }
 
-                       return { source };
+               try {
+                       sources += new SteamUriSource (home + STEAM_FLATPAK_DIR, FLATPAK_STEAM_FILE_SCHEME);
                }
                catch (Error e) {
                        debug (e.message);
                }
 
-               return {};
+               return sources;
        }
 
        public UriGameFactory[] get_uri_game_factories () {
@@ -32,13 +43,21 @@ private class Games.SteamPlugin : Object, Plugin {
                var factory = new GenericUriGameFactory (game_uri_adapter);
                factory.add_scheme (STEAM_FILE_SCHEME);
 
-               return { factory };
+               var game_uri_adapter_flatpak = new GenericGameUriAdapter (game_for_flatpak_steam_uri);
+               var factory_flatpak = new GenericUriGameFactory (game_uri_adapter_flatpak);
+               factory_flatpak.add_scheme (FLATPAK_STEAM_FILE_SCHEME);
+
+               return { factory, factory_flatpak };
        }
 
        private static Game game_for_steam_uri (Uri uri) throws Error {
                return create_game (uri, "steam", "", { "steam" });
        }
 
+       private static Game game_for_flatpak_steam_uri (Uri uri) throws Error {
+               return create_game (uri, STEAM_APPID, "flatpak", { "flatpak", "run", STEAM_APPID });
+       }
+
        private static Game create_game (Uri uri, string app_id, string prefix, string[] command) throws 
Error {
                var file_uri = new Uri.from_uri_and_scheme (uri, "file");
                var file = file_uri.to_file ();