examples: add C examples for monitoring whether NM runs

- the first uses dbus-glib and D-Bus "NameOwnerChanged" signal directly - the second uses GIO's g_bus_watch_name() - the third uses Qt and QDBusServiceWatcher class
2012-02-02 13:37:10 +01:00
parent 8ad3ff24ad
commit 38382770aa
6 changed files with 335 additions and 4 deletions
--- a/examples/C/qt/monitor-nm-running.cpp
+++ b/examples/C/qt/monitor-nm-running.cpp
@@ -0,0 +1,89 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
+/* vim: set ft=c ts=4 sts=4 sw=4 expandtab smartindent: */
+/*
+ * 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * (C) Copyright 2012 Red Hat, Inc.
+ */
+
+/*
+ * This example monitors whether NM is running by checking if
+ * "org.freedesktop.NetworkManager" is owned by a process on D-Bus.
+ * It uses QDBusServiceWatcher class.
+ *
+ * Standalone compilation:
+ *   moc-qt4 monitor-nm-running.cpp -o monitor-nm-running.moc
+ *   g++ -Wall `pkg-config --libs --cflags QtCore QtDBus` monitor-nm-running.cpp -o monitor-nm-running
+ *
+ * You don't need to have NetworkManager devel package installed.
+ */
+
+#include <iostream>
+#include <QObject>
+#include <QCoreApplication>
+#include <QtDBus/QDBusServiceWatcher>
+#include <QtDBus/QDBusConnection>
+#include <QtCore/QDebug>
+
+const QString NM_DBUS_SERVICE = "org.freedesktop.NetworkManager";
+
+// Define a class with slots
+class NMWatcher: public QObject {
+    Q_OBJECT;
+
+    public slots:
+        void serviceRegistered(const QString& name);
+        void serviceUnregistered(const QString& name);
+};
+
+
+void NMWatcher::serviceRegistered(const QString& name)
+{
+    std::cout << "Name '" << name.toStdString() << "' registered"
+              << " => NM is running" << std::endl;
+}
+
+void NMWatcher::serviceUnregistered(const QString& name)
+{
+    std::cout << "Name '" << name.toStdString() << "' unregistered"
+              << " => NM is not running" << std::endl;
+}
+
+int main(int argc, char *argv[])
+{
+    QCoreApplication app (argc, argv);
+
+    qDebug() << "Monitor 'org.freedesktop.NetworkManager' D-Bus name";
+    qDebug() << "===================================================";
+
+    NMWatcher nm_watcher;
+
+    // Watch all changes of D-Bus NM_DBUS_SERVICE name
+    QDBusServiceWatcher *watcher = new QDBusServiceWatcher(NM_DBUS_SERVICE,
+                                                           QDBusConnection::systemBus());
+
+    QObject::connect(watcher, SIGNAL(serviceRegistered(const QString&)),
+                     &nm_watcher, SLOT(serviceRegistered(const QString&)));
+
+    QObject::connect(watcher, SIGNAL(serviceUnregistered(const QString&)),
+                     &nm_watcher, SLOT(serviceUnregistered(const QString&)));
+
+    app.exec();
+
+    delete watcher;
+    return 0;
+}
+
+#include "monitor-nm-running.moc"