Start on global settings, add tint color setting

include/gui/GlobalSettingsPage.hpp

@@ -0,0 +1,34 @@
+#pragma once
+
+#include "StaticPage.hpp"
+#include "../GsrInfo.hpp"
+#include "../Config.hpp"
+
+namespace gsr {
+    class GsrPage;
+    class PageStack;
+    class ScrollablePage;
+    class Subsection;
+    class RadioButton;
+
+    class GlobalSettingsPage : public StaticPage {
+    public:
+        GlobalSettingsPage(const GsrInfo *gsr_info, Config &config, PageStack *page_stack);
+        GlobalSettingsPage(const GlobalSettingsPage&) = delete;
+        GlobalSettingsPage& operator=(const GlobalSettingsPage&) = delete;
+
+        void load();
+        void save();
+        void on_navigate_away_from_page() override;
+    private:
+        std::unique_ptr<Subsection> create_appearance_subsection(ScrollablePage *parent_page);
+        void add_widgets();
+    private:
+        Config &config;
+        const GsrInfo *gsr_info = nullptr;
+
+        GsrPage *content_page_ptr = nullptr;
+        PageStack *page_stack = nullptr;
+        RadioButton *tint_color_radio_button_ptr = nullptr;
+    };
+}