Fix recursive constructor invocation (#124)

src/Permissions/Backend/App.vala

@@ -121,7 +121,7 @@ public class Permissions.Backend.App : GLib.Object {
     private string get_overrides_path () {
         var overrides_folder_path = GLib.Path.build_path (
             GLib.Path.DIR_SEPARATOR_S,
-            AppManager.get_default ().user_installation_path,
+            FlatpakManager.get_default ().user_installation_path,
             "overrides"
         );
 

src/Permissions/Backend/AppManager.vala

@@ -21,7 +21,6 @@
 
 public class Permissions.Backend.AppManager : GLib.Object {
     public HashTable<string, Backend.App> apps { get; private set; }
-    public string user_installation_path { get; private set; }
 
     private static AppManager? instance;
     public static AppManager get_default () {
@@ -37,7 +36,6 @@ public class Permissions.Backend.AppManager : GLib.Object {
 
         try {
             var installation = new Flatpak.Installation.user ();
-            user_installation_path = installation.get_path ().get_path ();
             get_apps_for_installation (installation);
         } catch (Error e) {
             critical ("Unable to get flatpak user installation : %s", e.message);

src/Permissions/Backend/FlatpakManager.vala

@@ -0,0 +1,42 @@
+/*
+* Copyright 2020 elementary, Inc. (https://elementary.io)
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public
+* License as published by the Free Software Foundation; either
+* version 3 of the License, or (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+* General Public License for more details.
+*
+* You should have received a copy of the GNU General Public
+* License along with this program; if not, write to the
+* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+* Boston, MA 02110-1301 USA
+*
+* Authored by: Marius Meisenzahl <[email protected]>
+*/
+
+public class Permissions.Backend.FlatpakManager : GLib.Object {
+    public string user_installation_path { get; private set; }
+
+    private static FlatpakManager? instance;
+    public static FlatpakManager get_default () {
+        if (instance == null) {
+            instance = new FlatpakManager ();
+        }
+
+        return instance;
+    }
+
+    construct {
+        try {
+            var installation = new Flatpak.Installation.user ();
+            user_installation_path = installation.get_path ().get_path ();
+        } catch (Error e) {
+            critical ("Unable to get flatpak user installation : %s", e.message);
+        }
+    }
+}

src/meson.build

@@ -17,6 +17,7 @@ plug_files = files(
     'Defaults/DefaultPlug.vala',
     'Permissions/Backend/App.vala',
     'Permissions/Backend/AppManager.vala',
+    'Permissions/Backend/FlatpakManager.vala',
     'Permissions/Backend/PermissionSettings.vala',
     'Permissions/Widgets/AppSettingsView.vala',
     'Permissions/Widgets/PermissionSettingsWidget.vala',