NotificationServer: Add a system service for desktop notifications

This patch adds NotificationServer, which runs as the "notify" user
and provides an IPC API for desktop notifications.

LibGUI gains the GUI::Notification class for showing notifications.

NotificationServer is spawned on demand and will unspawn after
dimissing all visible notifications. :^)

Finally, this also comes with a small /bin/notify utility.

1 files changed, 49 insertions, 0 deletions

diff --git a/Userland/notify.cpp b/Userland/notify.cpp
new file mode 100644
index 0000000000..a1e0176dba
--- /dev/null
+++ b/Userland/notify.cpp
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <LibCore/ArgsParser.h>
+#include <LibGUI/Application.h>
+#include <LibGUI/Notification.h>
+#include <stdio.h>
+
+int main(int argc, char** argv)
+{
+    GUI::Application app(argc, argv);
+
+    Core::ArgsParser args_parser;
+    const char* title = nullptr;
+    const char* message = nullptr;
+    args_parser.add_positional_argument(title, "Title of the notification", "title");
+    args_parser.add_positional_argument(message, "Message to display in the notification", "message");
+    args_parser.parse(argc, argv);
+
+    auto notification = GUI::Notification::construct();
+    notification->set_text(message);
+    notification->set_title(title);
+    notification->show();
+
+    return 0;
+}