Keymap+WindowServer: Add context menu to keymap applet

Adding a context menu which lists configured keymaps and allows
setting the active keymap

Userland/Applets/Keymap/KeymapStatusWidget.cpp

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2022, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "KeymapStatusWidget.h"
+#include "LibGUI/ActionGroup.h"
+#include <LibGUI/Action.h>
+#include <LibGUI/ConnectionToWindowManagerServer.h>
+#include <LibGUI/Painter.h>
+#include <LibGUI/Process.h>
+#include <LibGfx/Point.h>
+#include <LibKeyboard/CharacterMap.h>
+
+void KeymapStatusWidget::mousedown_event(GUI::MouseEvent& event)
+{
+    Gfx::IntPoint point(event.x(), event.y());
+    MUST(refresh_menu());
+    m_context_menu->popup(point.translated(this->screen_relative_rect().location()));
+}
+
+ErrorOr<void> KeymapStatusWidget::refresh_menu()
+{
+    m_keymaps_group.for_each_action([&](auto& action) {
+        m_keymaps_group.remove_action(action);
+        return IterationDecision::Continue;
+    });
+
+    m_context_menu = GUI::Menu::construct();
+
+    auto mapper_config = TRY(Core::ConfigFile::open("/etc/Keyboard.ini"));
+    auto keymaps_string = mapper_config->read_entry("Mapping", "Keymaps", "");
+    auto keymaps = keymaps_string.split(',');
+
+    for (auto& keymap : keymaps) {
+        auto action = GUI::Action::create_checkable(keymap, [=](auto&) {
+            GUI::ConnectionToWindowManagerServer::the().async_set_keymap(keymap);
+        });
+
+        action->set_checked(keymap == m_current_keymap);
+
+        m_keymaps_group.add_action(action);
+        m_context_menu->add_action(action);
+    }
+
+    m_keymaps_group.set_exclusive(true);
+
+    m_context_menu->add_separator();
+
+    auto settings_icon = TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/settings.png"sv));
+
+    m_context_menu->add_action(GUI::Action::create("&Settings",
+        settings_icon,
+        [&](auto&) {
+            GUI::Process::spawn_or_show_error(window(), "/bin/KeyboardSettings"sv);
+        }));
+
+    return {};
+}
+
+void KeymapStatusWidget::set_current_keymap(String const& keymap, ClearBackground clear_background)
+{
+    if (clear_background == ClearBackground::Yes) {
+        GUI::Painter painter(*this);
+        painter.clear_rect(rect(), Color::Transparent);
+    }
+
+    m_current_keymap = keymap;
+
+    set_tooltip(keymap);
+    set_text(keymap.substring(0, 2));
+}