Ladybird: Convert `Browser::Settings` to a singleton

Ladybird/Qt/BrowserWindow.cpp

@@ -27,7 +27,6 @@
 #include <QTabBar>
 
 namespace Ladybird {
-extern Settings* s_settings;
 
 static QIcon const& app_icon()
 {
@@ -356,7 +355,7 @@ BrowserWindow::BrowserWindow(Optional<URL> const& initial_url, Browser::CookieJa
     });
 
     QObject::connect(new_tab_action, &QAction::triggered, this, [this] {
-        new_tab(s_settings->new_tab_page(), Web::HTML::ActivateTab::Yes);
+        new_tab(Settings::the()->new_tab_page(), Web::HTML::ActivateTab::Yes);
     });
     QObject::connect(open_file_action, &QAction::triggered, this, &BrowserWindow::open_file);
     QObject::connect(settings_action, &QAction::triggered, this, [this] {
@@ -401,7 +400,7 @@ BrowserWindow::BrowserWindow(Optional<URL> const& initial_url, Browser::CookieJa
         auto initial_url_string = qstring_from_ak_deprecated_string(initial_url->serialize());
         new_tab(initial_url_string, Web::HTML::ActivateTab::Yes);
     } else {
-        new_tab(s_settings->new_tab_page(), Web::HTML::ActivateTab::Yes);
+        new_tab(Settings::the()->new_tab_page(), Web::HTML::ActivateTab::Yes);
     }
 
     setCentralWidget(m_tabs_container);
@@ -696,9 +695,9 @@ bool BrowserWindow::eventFilter(QObject* obj, QEvent* event)
 
 void BrowserWindow::closeEvent(QCloseEvent* event)
 {
-    s_settings->set_last_position(pos());
-    s_settings->set_last_size(size());
-    s_settings->set_is_maximized(isMaximized());
+    Settings::the()->set_last_position(pos());
+    Settings::the()->set_last_size(size());
+    Settings::the()->set_is_maximized(isMaximized());
 
     QMainWindow::closeEvent(event);
 }

Ladybird/Qt/Settings.cpp

@@ -30,7 +30,7 @@ static QString rebase_default_url_on_serenity_resource_root(StringView default_u
 
 Settings::Settings()
 {
-    m_qsettings = new QSettings("Serenity", "Ladybird", this);
+    m_qsettings = make<QSettings>("Serenity", "Ladybird", this);
 }
 
 Optional<QPoint> Settings::last_position()

Ladybird/Qt/Settings.h

@@ -7,6 +7,7 @@
 #pragma once
 
 #include <AK/DeprecatedString.h>
+#include <AK/OwnPtr.h>
 #include <QPoint>
 #include <QSettings>
 #include <QSize>
@@ -15,7 +16,14 @@ namespace Ladybird {
 
 class Settings : public QObject {
 public:
-    Settings();
+    Settings(Settings const&) = delete;
+    Settings& operator=(Settings const&) = delete;
+
+    static Settings* the()
+    {
+        static Settings instance;
+        return &instance;
+    }
 
     Optional<QPoint> last_position();
     void set_last_position(QPoint const& last_position);
@@ -29,8 +37,11 @@ public:
     QString new_tab_page();
     void set_new_tab_page(QString const& page);
 
+protected:
+    Settings();
+
 private:
-    QSettings* m_qsettings;
+    OwnPtr<QSettings> m_qsettings;
 };
 
 }

Ladybird/Qt/SettingsDialog.cpp

@@ -13,8 +13,6 @@
 
 namespace Ladybird {
 
-extern Settings* s_settings;
-
 SettingsDialog::SettingsDialog(QMainWindow* window)
     : m_window(window)
 {
@@ -48,7 +46,7 @@ void SettingsDialog::save()
     auto url_string = MUST(ak_string_from_qstring(m_new_tab_page->text()));
     if (!URL(url_string).is_valid())
         return;
-    s_settings->set_new_tab_page(m_new_tab_page->text());
+    Settings::the()->set_new_tab_page(m_new_tab_page->text());
 }
 
 }

Ladybird/Qt/Tab.cpp

@@ -33,8 +33,6 @@ extern DeprecatedString s_serenity_resource_root;
 
 namespace Ladybird {
 
-extern Settings* s_settings;
-
 static QIcon create_tvg_icon_with_theme_colors(QString name, QPalette const& palette)
 {
     auto path = QString(":/Icons/%1.tvg").arg(name);

Ladybird/Qt/main.cpp

@@ -25,8 +25,6 @@
 
 namespace Ladybird {
 
-OwnPtr<Ladybird::Settings> s_settings;
-
 bool is_using_dark_system_theme(QWidget& widget)
 {
     // FIXME: Qt does not provide any method to query if the system is using a dark theme. We will have to implement
@@ -111,17 +109,16 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     if (auto url = TRY(get_formatted_url(raw_url)); url.is_valid())
         initial_url = move(url);
 
-    Ladybird::s_settings = adopt_own_if_nonnull(new Ladybird::Settings());
     Ladybird::BrowserWindow window(initial_url, cookie_jar, webdriver_content_ipc_path, enable_callgrind_profiling ? WebView::EnableCallgrindProfiling::Yes : WebView::EnableCallgrindProfiling::No, use_lagom_networking ? Ladybird::UseLagomNetworking::Yes : Ladybird::UseLagomNetworking::No);
     window.setWindowTitle("Ladybird");
 
-    if (Ladybird::s_settings->is_maximized()) {
+    if (Ladybird::Settings::the()->is_maximized()) {
         window.showMaximized();
     } else {
-        auto last_position = Ladybird::s_settings->last_position();
+        auto last_position = Ladybird::Settings::the()->last_position();
         if (last_position.has_value())
             window.move(last_position.value());
-        window.resize(Ladybird::s_settings->last_size());
+        window.resize(Ladybird::Settings::the()->last_size());
     }
 
     window.show();