[yelp] Use XDG_CURRENT_DESKTOP for conditionals when available

[Shaun McCance <shaunm src gnome org>]

commit 62e1f329533ddff346b619a5cd16d347a8d46c05
Author: Shaun McCance <shaunm gnome org>
Date:   Fri Aug 21 16:25:23 2015 -0400

    Use XDG_CURRENT_DESKTOP for conditionals when available
    
    Previously we had been using various DBus introspection routines to
    check the current desktop. That code is still there, but we don't
    use it if we can get the right information from XDG_CURRENT_DESKTOP.
    This adds more desktops we can check for, including gnome-shell
    derivatives like Elementary Pantheon and Cinnamon. We also set the
    new platform:gnome-3 token for GNOME 3 standard mode.

 libyelp/yelp-settings.c |  230 +++++++++++++++++++++++++++++-----------------
 1 files changed, 145 insertions(+), 85 deletions(-)
---
diff --git a/libyelp/yelp-settings.c b/libyelp/yelp-settings.c
index 8957dc2..fe0b49c 100644
--- a/libyelp/yelp-settings.c
+++ b/libyelp/yelp-settings.c
@@ -238,92 +238,11 @@ static void
 yelp_settings_constructed (GObject *object)
 {
     YelpSettings *settings = YELP_SETTINGS (object);
-    GDBusConnection *connection;
-    GVariant *ret, *names;
-    GVariantIter iter;
-    gchar *name;
-    gboolean env_shell, env_classic, env_panel, env_unity, env_xfce;
+    gboolean skip_dbus_checks = FALSE;
     gchar *os_release = NULL;
-    GError *error = NULL;
+    const gchar *desktop;
 
-    connection = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, &error);
-    if (connection == NULL) {
-        g_warning ("Unable to connect to dbus: %s", error->message);
-        g_error_free (error);
-        return;
-    }
-
-    ret = g_dbus_connection_call_sync (connection,
-                                       "org.freedesktop.DBus",
-                                       "/org/freedesktop/DBus",
-                                       "org.freedesktop.DBus",
-                                       "ListNames",
-                                       NULL,
-                                       G_VARIANT_TYPE ("(as)"),
-                                       G_DBUS_CALL_FLAGS_NONE,
-                                       -1, NULL, &error);
-    if (ret == NULL) {
-        g_warning ("Unable to query dbus: %s", error->message);
-        g_error_free (error);
-        return;
-    }
-    env_shell = env_classic = env_panel = env_unity = env_xfce = FALSE;
-    names = g_variant_get_child_value (ret, 0);
-    g_variant_iter_init (&iter, names);
-    while (g_variant_iter_loop (&iter, "&s", &name)) {
-        if (g_str_equal (name, "org.gnome.Panel"))
-            env_panel = TRUE;
-        else if (g_str_equal (name, "org.gnome.Shell"))
-            env_shell = TRUE;
-        else if (g_str_equal (name, "com.canonical.Unity"))
-            env_unity = TRUE;
-        else if (g_str_equal (name, "org.xfce.Panel"))
-            env_xfce = TRUE;
-    }
-    g_variant_unref (names);
-    g_variant_unref (ret);
-    if (env_shell) {
-        ret = g_dbus_connection_call_sync (connection,
-                                               "org.gnome.Shell",
-                                               "/org/gnome/Shell",
-                                               "org.freedesktop.DBus.Properties",
-                                               "Get",
-                                               g_variant_new ("(ss)",
-                                                              "org.gnome.Shell",
-                                                              "Mode"),
-                                               G_VARIANT_TYPE ("(v)"),
-                                               G_DBUS_CALL_FLAGS_NONE,
-                                               -1, NULL, &error);
-        if (ret == NULL) {
-            g_warning ("Failed to get GNOME shell mode: %s", error->message);
-            g_error_free (error);
-        } else {
-            GVariant *v;
-            g_variant_get (ret, "(v)", &v);
-            if (g_variant_is_of_type (v, G_VARIANT_TYPE_STRING) &&
-                g_str_equal (g_variant_get_string (v, NULL), "classic")) {
-                env_classic = TRUE;
-            }
-            g_variant_unref (v);
-            g_variant_unref (ret);
-        }
-    }
-
-    if (env_classic)
-        yelp_settings_set_if_token (settings, "platform:gnome-classic");
-
-    /* order is important:
-       gnome-shell also provides org.gnome.Panel
-       unity also provides org.gnome.Shell
-     */
-    if (env_unity)
-        yelp_settings_set_if_token (settings, "platform:unity");
-    else if (env_shell)
-        yelp_settings_set_if_token (settings, "platform:gnome-shell");
-    else if (env_xfce)
-        yelp_settings_set_if_token (settings, "platform:xfce");
-    else if (env_panel)
-        yelp_settings_set_if_token (settings, "platform:gnome-panel");
+    yelp_settings_set_if_token (settings, "action:install");
 
     g_file_get_contents ("/etc/os-release", &os_release, NULL, NULL);
     if (os_release == NULL)
@@ -384,7 +303,148 @@ yelp_settings_constructed (GObject *object)
         g_strfreev(lines);
     }
 
-    yelp_settings_set_if_token (settings, "action:install");
+    desktop = g_getenv ("XDG_CURRENT_DESKTOP");
+    if (desktop != NULL) {
+        gchar **desktops = g_strsplit (desktop, ":", -1);
+        gint i;
+        gboolean xdg_gnome = FALSE, xdg_gnome_classic = FALSE;
+        for (i = 0; desktops[i]; i++) {
+            if (!g_ascii_strcasecmp (desktops[i], "gnome")) {
+                xdg_gnome = TRUE;
+            }
+            else if (!g_ascii_strcasecmp (desktops[i], "gnome")) {
+                xdg_gnome_classic = TRUE;
+            }
+            else if (!g_ascii_strcasecmp (desktops[i], "kde")) {
+                yelp_settings_set_if_token (settings, "platform:kde");
+                skip_dbus_checks = TRUE;
+                break;
+            }
+            else if (!g_ascii_strcasecmp (desktops[i], "mate")) {
+                yelp_settings_set_if_token (settings, "platform:mate");
+                yelp_settings_set_if_token (settings, "platform:gnome-panel");
+                skip_dbus_checks = TRUE;
+                break;
+            }
+            else if (!g_ascii_strcasecmp (desktops[i], "pantheon")) {
+                yelp_settings_set_if_token (settings, "platform:pantheon");
+                yelp_settings_set_if_token (settings, "platform:gnome-shell");
+                skip_dbus_checks = TRUE;
+                break;
+            }
+            else if (!g_ascii_strcasecmp (desktops[i], "unity")) {
+                yelp_settings_set_if_token (settings, "platform:unity");
+                skip_dbus_checks = TRUE;
+                break;
+            }
+            else if (!g_ascii_strcasecmp (desktops[i], "x-cinnamon")) {
+                yelp_settings_set_if_token (settings, "platform:cinnamon");
+                yelp_settings_set_if_token (settings, "platform:gnome-shell");
+                skip_dbus_checks = TRUE;
+                break;
+            }
+        }
+        if (xdg_gnome) {
+            yelp_settings_set_if_token (settings, "platform:gnome-shell");
+            if (!xdg_gnome_classic)
+                yelp_settings_set_if_token (settings, "platform:gnome-3");
+            skip_dbus_checks = TRUE;
+        }
+        if (xdg_gnome_classic) {
+            yelp_settings_set_if_token (settings, "platform:gnome-classic");
+            yelp_settings_set_if_token (settings, "platform:gnome-shell");
+            skip_dbus_checks = TRUE;
+        }
+        g_strfreev (desktops);
+    }
+
+    if (!skip_dbus_checks) {
+        GDBusConnection *connection;
+        GVariant *ret, *names;
+        GVariantIter iter;
+        gchar *name;
+        gboolean env_shell, env_classic, env_panel, env_unity, env_xfce;
+        GError *error = NULL;
+
+        connection = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, &error);
+        if (connection == NULL) {
+            g_warning ("Unable to connect to dbus: %s", error->message);
+            g_error_free (error);
+            return;
+        }
+
+        ret = g_dbus_connection_call_sync (connection,
+                                           "org.freedesktop.DBus",
+                                           "/org/freedesktop/DBus",
+                                           "org.freedesktop.DBus",
+                                           "ListNames",
+                                           NULL,
+                                           G_VARIANT_TYPE ("(as)"),
+                                           G_DBUS_CALL_FLAGS_NONE,
+                                           -1, NULL, &error);
+        if (ret == NULL) {
+            g_warning ("Unable to query dbus: %s", error->message);
+            g_error_free (error);
+            return;
+        }
+        env_shell = env_classic = env_panel = env_unity = env_xfce = FALSE;
+        names = g_variant_get_child_value (ret, 0);
+        g_variant_iter_init (&iter, names);
+        while (g_variant_iter_loop (&iter, "&s", &name)) {
+            if (g_str_equal (name, "org.gnome.Panel"))
+                env_panel = TRUE;
+            else if (g_str_equal (name, "org.gnome.Shell"))
+                env_shell = TRUE;
+            else if (g_str_equal (name, "com.canonical.Unity"))
+                env_unity = TRUE;
+            else if (g_str_equal (name, "org.xfce.Panel"))
+                env_xfce = TRUE;
+        }
+        g_variant_unref (names);
+        g_variant_unref (ret);
+        if (env_shell) {
+            ret = g_dbus_connection_call_sync (connection,
+                                                   "org.gnome.Shell",
+                                                   "/org/gnome/Shell",
+                                                   "org.freedesktop.DBus.Properties",
+                                                   "Get",
+                                                   g_variant_new ("(ss)",
+                                                                  "org.gnome.Shell",
+                                                                  "Mode"),
+                                                   G_VARIANT_TYPE ("(v)"),
+                                                   G_DBUS_CALL_FLAGS_NONE,
+                                                   -1, NULL, &error);
+            if (ret == NULL) {
+                g_warning ("Failed to get GNOME shell mode: %s", error->message);
+                g_error_free (error);
+            } else {
+                GVariant *v;
+                g_variant_get (ret, "(v)", &v);
+                if (g_variant_is_of_type (v, G_VARIANT_TYPE_STRING) &&
+                    g_str_equal (g_variant_get_string (v, NULL), "classic")) {
+                    env_classic = TRUE;
+                }
+                g_variant_unref (v);
+                g_variant_unref (ret);
+            }
+        }
+
+        if (env_classic)
+            yelp_settings_set_if_token (settings, "platform:gnome-classic");
+
+        /* order is important:
+           gnome-shell also provides org.gnome.Panel
+           unity also provides org.gnome.Shell
+         */
+        if (env_unity)
+            yelp_settings_set_if_token (settings, "platform:unity");
+        else if (env_shell)
+            yelp_settings_set_if_token (settings, "platform:gnome-shell");
+        else if (env_xfce)
+            yelp_settings_set_if_token (settings, "platform:xfce");
+        else if (env_panel)
+            yelp_settings_set_if_token (settings, "platform:gnome-panel");
+    }
 }
 
 static void