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.

Servers/NotificationServer/ClientConnection.cpp

@@ -0,0 +1,62 @@
+/*
+ * 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 "ClientConnection.h"
+#include "NotificationClientEndpoint.h"
+#include "NotificationWindow.h"
+#include <AK/HashMap.h>
+
+namespace NotificationServer {
+
+static HashMap<int, RefPtr<ClientConnection>> s_connections;
+
+ClientConnection::ClientConnection(Core::LocalSocket& client_socket, int client_id)
+    : IPC::ClientConnection<NotificationServerEndpoint>(*this, client_socket, client_id)
+{
+    s_connections.set(client_id, *this);
+}
+
+ClientConnection::~ClientConnection()
+{
+}
+
+void ClientConnection::die()
+{
+    s_connections.remove(client_id());
+}
+
+OwnPtr<Messages::NotificationServer::GreetResponse> ClientConnection::handle(const Messages::NotificationServer::Greet&)
+{
+    return make<Messages::NotificationServer::GreetResponse>(client_id());
+}
+
+void ClientConnection::handle(const Messages::NotificationServer::ShowNotification& message)
+{
+    auto window = NotificationWindow::construct(message.text(), message.title());
+    window->show();
+}
+
+}

Servers/NotificationServer/ClientConnection.h

@@ -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.
+ */
+
+#pragma once
+
+#include <LibIPC/ClientConnection.h>
+#include <NotificationServer/NotificationServerEndpoint.h>
+
+namespace NotificationServer {
+
+class ClientConnection final : public IPC::ClientConnection<NotificationServerEndpoint>
+    , public NotificationServerEndpoint {
+    C_OBJECT(ClientConnection)
+public:
+    ~ClientConnection() override;
+
+    virtual void die() override;
+
+private:
+    explicit ClientConnection(Core::LocalSocket&, int client_id);
+
+    virtual OwnPtr<Messages::NotificationServer::GreetResponse> handle(const Messages::NotificationServer::Greet&) override;
+    virtual void handle(const Messages::NotificationServer::ShowNotification&) override;
+};
+
+}

Servers/NotificationServer/Makefile

@@ -0,0 +1,24 @@
+OBJS = \
+    main.o \
+    ClientConnection.o \
+    NotificationWindow.o
+
+PROGRAM = NotificationServer
+
+LIB_DEPS = GUI Gfx Core IPC
+
+EXTRA_CLEAN = NotificationServerEndpoint.h NotificationClientEndpoint.h
+
+*.cpp: NotificationServerEndpoint.h NotificationClientEndpoint.h
+
+NotificationServerEndpoint.h: NotificationServer.ipc | IPCCOMPILER
+	@echo "IPC $<"; $(IPCCOMPILER) $< > $@
+
+NotificationClientEndpoint.h: NotificationClient.ipc | IPCCOMPILER
+	@echo "IPC $<"; $(IPCCOMPILER) $< > $@
+
+install:
+	mkdir -p $(SERENITY_BASE_DIR)/Root/usr/include/NotificationServer/
+	cp *.h $(SERENITY_BASE_DIR)/Root/usr/include/NotificationServer/
+
+include ../../Makefile.common

Servers/NotificationServer/NotificationClient.ipc

@@ -0,0 +1,4 @@
+endpoint NotificationClient = 92
+{
+    Dummy() =|
+}

Servers/NotificationServer/NotificationServer.ipc

@@ -0,0 +1,7 @@
+endpoint NotificationServer = 95
+{
+    // Basic protocol
+    Greet() => (i32 client_id)
+
+    ShowNotification(String text, String title) =|
+}

Servers/NotificationServer/NotificationWindow.cpp

@@ -0,0 +1,86 @@
+/*
+ * 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 "NotificationWindow.h"
+#include <AK/HashTable.h>
+#include <LibGUI/BoxLayout.h>
+#include <LibGUI/Button.h>
+#include <LibGUI/Desktop.h>
+#include <LibGUI/Label.h>
+#include <LibGUI/Widget.h>
+#include <LibGfx/Font.h>
+
+namespace NotificationServer {
+
+static HashTable<RefPtr<NotificationWindow>> s_windows;
+
+NotificationWindow::NotificationWindow(const String& text, const String& title)
+{
+    s_windows.set(this);
+
+    set_window_type(GUI::WindowType::Tooltip);
+
+    Gfx::Rect rect;
+    rect.set_width(200);
+    rect.set_height(40);
+    rect.set_location(GUI::Desktop::the().rect().top_right().translated(-rect.width() - 8, 26));
+    set_rect(rect);
+
+    auto widget = GUI::Widget::construct();
+    widget->set_fill_with_background_color(true);
+
+    widget->set_layout(make<GUI::HorizontalBoxLayout>());
+    widget->layout()->set_margins({ 4, 4, 4, 4 });
+    widget->layout()->set_spacing(4);
+
+    auto left_container = GUI::Widget::construct(widget.ptr());
+    left_container->set_layout(make<GUI::VerticalBoxLayout>());
+
+    auto title_label = GUI::Label::construct(title, left_container);
+    title_label->set_font(Gfx::Font::default_bold_font());
+    title_label->set_text_alignment(Gfx::TextAlignment::CenterLeft);
+    auto text_label = GUI::Label::construct(text, left_container);
+    text_label->set_text_alignment(Gfx::TextAlignment::CenterLeft);
+
+    auto right_container = GUI::Widget::construct(widget.ptr());
+    right_container->set_size_policy(GUI::SizePolicy::Fixed, GUI::SizePolicy::Fill);
+    right_container->set_preferred_size(40, 0);
+    right_container->set_layout(make<GUI::HorizontalBoxLayout>());
+
+    auto button = GUI::Button::construct("Okay", right_container);
+    button->on_click = [this](auto&) {
+        s_windows.remove(this);
+        close();
+    };
+
+    set_main_widget(widget);
+}
+
+NotificationWindow::~NotificationWindow()
+{
+}
+
+}

Servers/NotificationServer/NotificationWindow.h

@@ -0,0 +1,43 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <LibGUI/Window.h>
+
+namespace NotificationServer {
+
+class NotificationWindow final : public GUI::Window {
+    C_OBJECT(NotificationWindow);
+
+public:
+    virtual ~NotificationWindow() override;
+
+private:
+    NotificationWindow(const String& text, const String& title);
+};
+
+}

Servers/NotificationServer/main.cpp

@@ -0,0 +1,71 @@
+/*
+ * 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 "ClientConnection.h"
+#include <LibCore/EventLoop.h>
+#include <LibCore/LocalServer.h>
+#include <LibGUI/Application.h>
+#include <LibGUI/WindowServerConnection.h>
+#include <stdio.h>
+#include <unistd.h>
+
+int main(int argc, char** argv)
+{
+    if (pledge("stdio shared_buffer accept rpath wpath cpath unix fattr", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
+    GUI::Application app(argc, argv);
+    auto server = Core::LocalServer::construct();
+
+    bool ok = server->take_over_from_system_server();
+    ASSERT(ok);
+    server->on_ready_to_accept = [&] {
+        auto client_socket = server->accept();
+        if (!client_socket) {
+            dbg() << "NotificationServer: accept failed.";
+            return;
+        }
+        static int s_next_client_id = 0;
+        int client_id = ++s_next_client_id;
+        IPC::new_client_connection<NotificationServer::ClientConnection>(*client_socket, client_id);
+    };
+
+    if (unveil("/res", "r") < 0) {
+        perror("unveil");
+        return 1;
+    }
+
+    unveil(nullptr, nullptr);
+
+    if (pledge("stdio shared_buffer accept rpath", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
+    return app.exec();
+}