[glib] Add portal helpers

[Matthias Clasen <matthiasc src gnome org>]

commit 78ef32110a4b46d05cdc3b3273583ef1aed9f75a
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Jul 6 23:34:55 2016 -0400

    Add portal helpers
    
    These are private helper functions that will be used in
    the following commits to get information about whether
    we are running in a flatpak sandbox, etc.
    
    We allow the use of GTK_USE_PORTAL=1 in the environment
    to force the use of portals. This can be useful for
    testing and debugging portal interaction.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=768498

 gio/Makefile.am      |    2 +
 gio/gportalsupport.c |   84 ++++++++++++++++++++++++++++++++++++++++++++++++++
 gio/gportalsupport.h |   30 ++++++++++++++++++
 3 files changed, 116 insertions(+), 0 deletions(-)
---
diff --git a/gio/Makefile.am b/gio/Makefile.am
index 3b3c104..9a0d758 100644
--- a/gio/Makefile.am
+++ b/gio/Makefile.am
@@ -424,6 +424,8 @@ libgio_2_0_la_SOURCES =             \
        gpollableutils.c        \
        gpollfilemonitor.c      \
        gpollfilemonitor.h      \
+       gportalsupport.c        \
+       gportalsupport.h        \
        gproxy.c                \
        gproxyaddress.c         \
        gproxyaddressenumerator.c \
diff --git a/gio/gportalsupport.c b/gio/gportalsupport.c
new file mode 100644
index 0000000..4532cf0
--- /dev/null
+++ b/gio/gportalsupport.c
@@ -0,0 +1,84 @@
+/* GIO - GLib Input, Output and Streaming Library
+ *
+ * Copyright 2016 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include "gportalsupport.h"
+
+static gboolean flatpak_info_read;
+static gboolean use_portal;
+static gboolean network_available;
+
+static void
+read_flatpak_info (void)
+{
+  char *path;
+
+  if (flatpak_info_read)
+    return;
+
+  flatpak_info_read = TRUE;
+
+  path = g_build_filename (g_get_user_runtime_dir (), "flatpak-info", NULL);
+  if (g_file_test (path, G_FILE_TEST_EXISTS))
+    {
+      GKeyFile *keyfile;
+
+      use_portal = TRUE;
+      network_available = FALSE;
+
+      keyfile = g_key_file_new ();
+      if (g_key_file_load_from_file (keyfile, path, G_KEY_FILE_NONE, NULL))
+        {
+          char **shared = NULL;
+
+          shared = g_key_file_get_string_list (keyfile, "Context", "shared", NULL, NULL);
+          if (shared)
+            {
+              network_available = g_strv_contains ((const char * const *)shared, "network");
+              g_strfreev (shared);
+            }
+        }
+    }
+  else
+    {
+      const char *var;
+
+      var = g_getenv ("GTK_USE_PORTAL");
+      if (var && var[0] == '1')
+        use_portal = TRUE;
+      network_available = TRUE;
+    }
+
+  g_free (path);
+}
+
+gboolean
+glib_should_use_portal (void)
+{
+  read_flatpak_info ();
+  return use_portal;
+}
+
+gboolean
+glib_network_available_in_sandbox (void)
+{
+  read_flatpak_info ();
+  return network_available;
+}
+
diff --git a/gio/gportalsupport.h b/gio/gportalsupport.h
new file mode 100644
index 0000000..a92e07c
--- /dev/null
+++ b/gio/gportalsupport.h
@@ -0,0 +1,30 @@
+/* GIO - GLib Input, Output and Streaming Library
+ *
+ * Copyright 2016 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __G_PORTAL_SUPPORT_H__
+
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+gboolean glib_should_use_portal (void);
+gboolean glib_network_available_in_sandbox (void);
+
+G_END_DECLS
+
+#endif