use current running DM preferences program

1 files changed, 158 insertions, 0 deletions

diff --git a/capplets/accessibility/at-properties/dm-util.c b/capplets/accessibility/at-properties/dm-util.c
new file mode 100644
index 00000000..79c5e6e5
--- /dev/null
+++ b/capplets/accessibility/at-properties/dm-util.c
@@ -0,0 +1,158 @@
+/* vi: set sw=4 ts=4 wrap ai: */
+/*
+ * dm-util.c: This file is part of mate-control-center.
+ *
+ * Copyright (C) 2019 Wu Xiaotian <[email protected]>
+ *
+ * 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 2 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, see <http://www.gnu.org/licenses/>.
+ * */
+
+#include <gio/gio.h>
+#include "dm-util.h"
+
+static GDBusProxy *get_sys_proxy (void)
+{
+    GError     *error = NULL;
+    GDBusProxy *proxy = NULL;
+
+    proxy = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SYSTEM,
+                                           G_DBUS_PROXY_FLAGS_NONE,
+                                           NULL,
+                                           "org.freedesktop.DBus",
+                                           "/org/freedesktop/DBus",
+                                           "org.freedesktop.DBus",
+                                           NULL,
+                                           &error);
+    if (proxy == NULL) {
+        g_warning ("Couldn't connect to system bus: %s", error->message);
+        g_error_free (error);
+    }
+    return proxy;
+}
+
+static gboolean dm_is_running (void)
+{
+    GDBusProxy *proxy;
+    GError *error = NULL;
+    GVariant *ret;
+    gboolean running = FALSE;
+
+    proxy = get_sys_proxy ();
+    if (proxy == NULL)
+        return FALSE;
+
+    ret = g_dbus_proxy_call_sync (proxy,
+                                  "NameHasOwner",
+                                  g_variant_new ("(s)", "org.freedesktop.DisplayManager"),
+                                  G_DBUS_CALL_FLAGS_NONE,
+                                  -1,
+                                  NULL,
+                                  &error);
+    if (ret == NULL) {
+        g_warning ("Couldn't call dbus method: %s", error->message);
+        g_error_free (error);
+    } else {
+        g_variant_get (ret, "(b)", &running);
+        g_variant_unref (ret);
+    }
+
+    if (proxy)
+        g_object_unref (proxy);
+
+    return running;
+}
+
+static gint
+dm_get_pid (GError **err)
+{
+    GDBusProxy *proxy;
+    GError *error = NULL;
+    GVariant *ret;
+    guint32 pid = 0;
+
+    proxy = get_sys_proxy ();
+    if (proxy == NULL)
+        return FALSE;
+
+    ret = g_dbus_proxy_call_sync (proxy,
+                                  "GetConnectionUnixProcessID",
+                                  g_variant_new ("(s)", "org.freedesktop.DisplayManager"),
+                                  G_DBUS_CALL_FLAGS_NONE,
+                                  -1,
+                                  NULL,
+                                  &error);
+    if (ret == NULL) {
+        g_propagate_error (err, error);
+    } else {
+        g_variant_get (ret, "(u)", &pid);
+        g_variant_unref (ret);
+    }
+
+    if (proxy)
+        g_object_unref (proxy);
+
+    return pid;
+}
+
+static gchar* get_cmdline_from_pid (gint pid)
+{
+    gchar path[255];
+    gchar *text = NULL;
+    gchar *cmdline = NULL;
+    GError *error = NULL;
+
+    g_snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
+    if (!g_file_get_contents (path, &text, NULL, &error)) {
+        g_warning ("get cmdline error: %s\n", error->message);
+        g_error_free (error);
+        return NULL;
+    } else {
+        cmdline = g_path_get_basename (text);
+        g_free (text);
+    }
+    return cmdline;
+}
+
+DMType dm_get_type(void)
+{
+    gint pid;
+    gchar *cmdline;
+
+    DMType dmtype = DM_TYPE_UNKNOWN;
+
+    if (!dm_is_running()) {
+        goto ret;
+    }
+
+    pid = dm_get_pid (NULL);
+    if (pid <= 1) {
+        goto ret;
+    }
+
+    cmdline = get_cmdline_from_pid (pid);
+    if (cmdline == NULL) {
+        goto ret;
+    }
+
+    if (g_strcmp0(cmdline, "lightdm") == 0) {
+        dmtype = DM_TYPE_LIGHTDM;
+    } else if (g_strcmp0(cmdline, "mdm") == 0) {
+        dmtype = DM_TYPE_MDM;
+    } else if (g_strcmp0(cmdline, "gdm") == 0) {
+        dmtype = DM_TYPE_GDM;
+    }
+    g_free (cmdline);
+ret:
+    return dmtype;
+}