Merge remote-tracking branch 'gh-Ionic/feature/high-contrast-big-font'

Attributes GH PR #40: https://github.com/ArcticaProject/arctica-greeter/pull/40

19 files changed, 823 insertions, 139 deletions

diff --git a/configure.ac b/configure.ac
index 222556a..7619254 100644
--- a/configure.ac
+++ b/configure.ac
@@ -91,6 +91,16 @@ if test x$gtk_check_pass = xyes ; then
   AC_SUBST([AM_VALAFLAGS])
 fi
 
+dnl ###########################################################################
+dnl Check for GTK version - 4.0
+dnl ###########################################################################
+
+PKG_CHECK_MODULES(GTK_4_0, gtk4 >= 4.0.0 , gtk4_check_pass=yes, gtk4_check_pass=no)
+if test x$gtk4_check_pass = xyes ; then
+  AM_VALAFLAGS="$AM_VALAFLAGS -D HAVE_GTK_4_0"
+  AC_SUBST([AM_VALAFLAGS])
+fi
+
 dnl ##########################################################################
 dnl Remote Logon Dependencies
 dnl ##########################################################################
diff --git a/data/org.ArcticaProject.arctica-greeter.gschema.xml b/data/org.ArcticaProject.arctica-greeter.gschema.xml
index 9efc200..b0069c2 100644
--- a/data/org.ArcticaProject.arctica-greeter.gschema.xml
+++ b/data/org.ArcticaProject.arctica-greeter.gschema.xml
@@ -37,6 +37,10 @@
       <default>'Blue-Submarine'</default>
       <summary>GTK+ theme to use</summary>
     </key>
+    <key name="high-contrast-theme-name" type="s">
+      <default>'HighContrastInverse'</default>
+      <summary>GTK+ theme to use in high contrast mode</summary>
+    </key>
     <key name="icon-theme-name" type="s">
       <default>'Adwaita'</default>
       <summary>Icon theme to use</summary>
@@ -82,6 +86,10 @@
       <default>false</default>
       <summary>Whether to use a high contrast theme</summary>
     </key>
+    <key name="big-font" type="b">
+      <default>false</default>
+      <summary>Whether to use big fonts throughout the application</summary>
+    </key>
     <key name="screen-reader" type="b">
       <default>false</default>
       <summary>Whether to enable the screen reader</summary>
@@ -115,6 +123,10 @@
       <default>'auto'</default>
       <summary>Whether to enable HiDPI support</summary>
     </key>
+    <key name="menubar-alpha" type="d">
+      <default>0.5</default>
+      <summary>Alpha value for menubar, multiplied with the theme-provided transparency value. Not used in high contrast mode.</summary>
+    </key>
     <key name="remote-service-configure-uri" type="s">
       <default>''</default>
       <summary>Default FQDN for host offering Remote Logon Service</summary>
diff --git a/src/Makefile.am b/src/Makefile.am
index 5c0c78f..4c10950 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -37,7 +37,8 @@ arctica_greeter_SOURCES = \
 	toggle-box.vala \
 	arctica-greeter.vala \
 	user-list.vala \
-	user-prompt-box.vala
+	user-prompt-box.vala \
+	util.vala
 
 logo_generator_SOURCES = logo-generator.vala
 
diff --git a/src/arctica-greeter.vala b/src/arctica-greeter.vala
index 96a98ce..6d31a9b 100644
--- a/src/arctica-greeter.vala
+++ b/src/arctica-greeter.vala
@@ -21,16 +21,15 @@
 
 public const int grid_size = 40;
 
-public class ArcticaGreeter
+[SingleInstance]
+public class ArcticaGreeter : Object
 {
-    public static ArcticaGreeter singleton;
-
     public signal void show_message (string text, LightDM.MessageType type);
     public signal void show_prompt (string text, LightDM.PromptType type);
     public signal void authentication_complete ();
     public signal void starting_session ();
 
-    public bool test_mode = false;
+    public bool test_mode { get; construct; default = false; }
 
     private string state_file;
     private KeyFile state;
@@ -53,11 +52,8 @@ public class ArcticaGreeter
     public signal void xsettings_ready ();
     public signal void greeter_ready ();
 
-    private ArcticaGreeter (bool test_mode_)
+    construct
     {
-        singleton = this;
-        test_mode = test_mode_;
-
         greeter = new LightDM.Greeter ();
         greeter.show_message.connect ((text, type) => { show_message (text, type); });
         greeter.show_prompt.connect ((text, type) => { show_prompt (text, type); });
@@ -140,6 +136,22 @@ public class ArcticaGreeter
             xsettings_ready_cb ();
     }
 
+    /*
+     * Note that we need a way to specify a parameter for the initial instance
+     * creation of the singleton, but also a constructor that takes no
+     * parameters for later usage.
+     *
+     * Making the parameter optional is a good compromise.
+     *
+     * This this parameter is construct-only, initializing it by passing it to
+     * the GObject constructor is both the correct way to do it, and it will
+     * additionally avoid changing it in later calls of our constructor.
+     */
+    public ArcticaGreeter (bool test_mode_ = false)
+    {
+        Object (test_mode: test_mode_);
+    }
+
     public string? get_state (string key)
     {
         try
@@ -294,6 +306,47 @@ public class ArcticaGreeter
                                    Canberra.PROP_EVENT_ID,
                                    "system-ready");
 
+        /* Synchronize properties in AGSettings once. */
+        var agsettings = new AGSettings ();
+        agsettings.high_contrast = !(!(agsettings.high_contrast));
+        agsettings.big_font = !(!(agsettings.big_font));
+
+        /*
+         * Add timeouts to process the full node hierarchy to handle a11y
+         * changes.
+         *
+         * That's the easiest way to handle a changing node hierarchy.
+         *
+         * Alternatives would involve connecting a function for every a11y
+         * change to the GtkWidget::parent-set event to *every widget* we
+         * create, but that would make the code incredibly messy.
+         *
+         * The value has been determined by a fair dice roll and should make
+         * sure that changes are visible almost instantaneously to users.
+         */
+        Timeout.add_full (GLib.Priority.HIGH_IDLE, 302, () => {
+            var agsettings_intimer = new AGSettings ();
+            /*
+            if (0 == GLib.Random.int_range (0, 10)) {
+                debug ("Syncing up high contrast value via timer: %s", agsettings_intimer.high_contrast.to_string ());
+            }
+            */
+            switch_contrast (agsettings_intimer.high_contrast);
+
+            return true;
+        });
+        Timeout.add_full (GLib.Priority.HIGH_IDLE, 302, () => {
+            var agsettings_intimer = new AGSettings ();
+            /*
+            if (0 == GLib.Random.int_range (0, 10)) {
+                debug ("Syncing up big font value via timer: %s", agsettings_intimer.big_font.to_string ());
+            }
+            */
+            switch_font (agsettings_intimer.big_font);
+
+            return true;
+        });
+
         return false;
     }
 
@@ -340,7 +393,7 @@ public class ArcticaGreeter
     {
         try
         {
-            ArcticaGreeter.singleton.greeter.authenticate_remote (session, userid);
+            greeter.authenticate_remote (session, userid);
         }
         catch (Error e)
         {
@@ -407,6 +460,75 @@ public class ArcticaGreeter
         return greeter.has_guest_account_hint;
     }
 
+    private delegate void SwitchClassType (Gtk.Widget widget, string classname, bool enable);
+
+    private delegate void IterateChildrenType (Gtk.Widget widget);
+
+    private void switch_generic (Gtk.Widget widget, string classname, bool enable)
+    {
+        var style_ctx = widget.get_style_context ();
+        if (enable)
+        {
+            style_ctx.add_class (classname);
+        }
+        else
+        {
+            style_ctx.remove_class (classname);
+        }
+    }
+
+    private void iterate_children_generic (Gtk.Widget widget, SwitchClassType switch_func, string classname, bool enable)
+    {
+        /*
+         * GTK 4 changed its API quite dramatically, got rid of GtkContainer
+         * and made each GtkWidget accept children, while also defining a new
+         * way to access those.
+         */
+        IterateChildrenType rec_func = null;
+        rec_func = (widget) => {
+#if HAVE_GTK_4_0
+            Gtk.Widget child = widget.get_first_child ();
+            while (null != child)
+            {
+                rec_func (child);
+                child = child.get_next_sibling ();
+            }
+#else
+            if (gtk_is_container (widget))
+            {
+                ((Gtk.Container)(widget)).@foreach (rec_func);
+            }
+#endif
+
+            /* Common code to add or remove the CSS class. */
+            switch_func (widget, classname, enable);
+        };
+
+        /*
+         * Actually recursively iterate through this item and all of its
+         * children.
+         */
+        rec_func (widget);
+    }
+
+    public void switch_contrast (bool high)
+    {
+        var time_pre = GLib.get_monotonic_time ();
+        iterate_children_generic (main_window, switch_generic, "high_contrast", high);
+        var time_post = GLib.get_monotonic_time ();
+        var time_diff = time_post - time_pre;
+        assert (0 <= time_diff);
+        var time_diff_sec = time_diff / 1000000;
+        var time_diff_msec = time_diff / 1000;
+        var time_diff_usec = time_diff % 1000000;
+        // debug ("Time passed: %" + int64.FORMAT + " s, %" + int64.FORMAT + " ms, %" + int64.FORMAT + " us", time_diff_sec, time_diff_msec, time_diff_usec);
+    }
+
+    public void switch_font (bool big)
+    {
+        iterate_children_generic (main_window, switch_generic, "big_font", big);
+    }
+
     private Gdk.FilterReturn focus_upon_map (Gdk.XEvent gxevent, Gdk.Event event)
     {
         var xevent = (X.Event*)gxevent;
@@ -807,6 +929,16 @@ public class ArcticaGreeter
         if (value != "")
             settings.set ("gtk-xft-rgba", value, null);
 
+        /*
+         * Keep a reference to an AGSettings instance for the whole program
+         * run, so that the SingleInstance property is working the way we'd
+         * like it to work.
+         *
+         * We want to do this before creating the actual greeter, since the
+         * latter is using AGSettings quite extensively.
+         */
+        var agsettings = new AGSettings ();
+
         debug ("Creating Arctica Greeter");
         var greeter = new ArcticaGreeter (do_test_mode);
 
diff --git a/src/background.vala b/src/background.vala
index 9a77047..18bf169 100644
--- a/src/background.vala
+++ b/src/background.vala
@@ -778,7 +778,8 @@ public class Background : Gtk.Fixed
     {
         notify_property ("average-color");
 
-        if (!ArcticaGreeter.singleton.test_mode)
+        var greeter = new ArcticaGreeter ();
+        if (!greeter.test_mode)
         {
             var rgba = current.average_color.to_string ();
             var root = get_screen ().get_root_window ();
diff --git a/src/dash-box.vala b/src/dash-box.vala
index cc1d715..1073aa5 100644
--- a/src/dash-box.vala
+++ b/src/dash-box.vala
@@ -54,7 +54,8 @@ public class DashBox : Gtk.Box
     /* Does not actually add w to this widget, as doing so would potentially mess with w's placement. */
     public void set_base (Gtk.Widget? w)
     {
-        if (!ArcticaGreeter.singleton.test_mode) {
+        var greeter = new ArcticaGreeter ();
+        if (!greeter.test_mode) {
             return_if_fail (pushed == null);
             return_if_fail (mode == Mode.NORMAL);
         }
@@ -220,10 +221,25 @@ public class DashBox : Gtk.Box
 
         CairoUtils.rounded_rectangle (c, 0, box_y, box_w, box_h, box_r);
 
-        c.set_source_rgba (0.1, 0.1, 0.1, 0.4);
+        var agsettings = new AGSettings ();
+        if (agsettings.high_contrast)
+        {
+            c.set_source_rgba (1.0, 1.0, 1.0, 1.0);
+        }
+        else
+        {
+            c.set_source_rgba (0.1, 0.1, 0.1, 0.4);
+        }
         c.fill_preserve ();
 
-        c.set_source_rgba (0.4, 0.4, 0.4, 0.4);
+        if (agsettings.high_contrast)
+        {
+            c.set_source_rgba (0.0, 0.0, 0.0, 1.0);
+        }
+        else
+        {
+            c.set_source_rgba (0.4, 0.4, 0.4, 0.4);
+        }
         c.set_line_width (1);
         c.stroke ();
 
diff --git a/src/dash-entry.vala b/src/dash-entry.vala
index 526b631..4d1146d 100644
--- a/src/dash-entry.vala
+++ b/src/dash-entry.vala
@@ -301,10 +301,11 @@ public class DashEntry : Gtk.Entry, Fadable
         // This is a workaround for bug https://launchpad.net/bugs/944159
         // The problem is that orca seems to not notice that it's in a password
         // field on startup.  We just need to kick orca in the pants.
-        if (ArcticaGreeter.singleton.orca_needs_kick)
+        var greeter = new ArcticaGreeter ();
+        if (greeter.orca_needs_kick)
         {
             Signal.emit_by_name (get_accessible (), "focus-event", true);
-            ArcticaGreeter.singleton.orca_needs_kick = false;
+            greeter.orca_needs_kick = false;
         }
 
         return base.key_press_event (event);
diff --git a/src/greeter-list.vala b/src/greeter-list.vala
index 0cc3a1f..98c8b48 100644
--- a/src/greeter-list.vala
+++ b/src/greeter-list.vala
@@ -229,7 +229,8 @@ public abstract class GreeterList : FadableBox
 
     public void cancel_authentication ()
     {
-        ArcticaGreeter.singleton.cancel_authentication ();
+        var greeter = new ArcticaGreeter ();
+        greeter.cancel_authentication ();
         entry_selected (selected_entry.id);
     }
 
@@ -483,7 +484,8 @@ public abstract class GreeterList : FadableBox
         entry.destroy ();
 
         /* Show a manual login if no users and no remote login entry */
-        if (!have_entries () && !ArcticaGreeter.singleton.show_remote_login_hint ())
+        var greeter = new ArcticaGreeter ();
+        if (!have_entries () && !greeter.show_remote_login_hint ())
             add_manual_entry ();
 
         queue_draw ();
@@ -793,9 +795,10 @@ public abstract class GreeterList : FadableBox
 
     protected void connect_to_lightdm ()
     {
-        ArcticaGreeter.singleton.show_message.connect (show_message_cb);
-        ArcticaGreeter.singleton.show_prompt.connect (show_prompt_cb);
-        ArcticaGreeter.singleton.authentication_complete.connect (authentication_complete_cb);
+        var greeter = new ArcticaGreeter ();
+        greeter.show_message.connect (show_message_cb);
+        greeter.show_prompt.connect (show_prompt_cb);
+        greeter.authentication_complete.connect (authentication_complete_cb);
     }
 
     protected void show_message_cb (string text, LightDM.MessageType type)
@@ -809,10 +812,11 @@ public abstract class GreeterList : FadableBox
         /* Notify the greeter on what user has been logged */
         if (get_selected_id () == "*other" && manual_name == null)
         {
-            if (ArcticaGreeter.singleton.test_mode)
+            var greeter = new ArcticaGreeter ();
+            if (greeter.test_mode)
                 manual_name = test_username;
             else
-                manual_name = ArcticaGreeter.singleton.authentication_user();
+                manual_name = greeter.authentication_user();
         }
 
         prompted = true;
@@ -841,10 +845,11 @@ public abstract class GreeterList : FadableBox
             return;
 
         bool is_authenticated;
-        if (ArcticaGreeter.singleton.test_mode)
+        var greeter = new ArcticaGreeter ();
+        if (greeter.test_mode)
             is_authenticated = test_is_authenticated;
         else
-            is_authenticated = ArcticaGreeter.singleton.is_authenticated();
+            is_authenticated = greeter.is_authenticated();
 
         if (is_authenticated)
         {
@@ -852,7 +857,7 @@ public abstract class GreeterList : FadableBox
             if (prompted && !unacknowledged_messages)
             {
                 login_complete ();
-                if (ArcticaGreeter.singleton.test_mode)
+                if (greeter.test_mode)
                     start_session ();
                 else
                 {
@@ -905,16 +910,17 @@ public abstract class GreeterList : FadableBox
 
         greeter_authenticating_user = get_selected_id ();
 
-        if (ArcticaGreeter.singleton.test_mode)
+        var greeter = new ArcticaGreeter ();
+        if (greeter.test_mode)
             test_start_authentication ();
         else
         {
             if (get_selected_id () == "*other")
-                ArcticaGreeter.singleton.authenticate ();
+                greeter.authenticate ();
             else if (get_selected_id () == "*guest")
-                ArcticaGreeter.singleton.authenticate_as_guest ();
+                greeter.authenticate_as_guest ();
             else
-                ArcticaGreeter.singleton.authenticate (get_selected_id ());
+                greeter.authenticate (get_selected_id ());
         }
     }
 
@@ -929,7 +935,8 @@ public abstract class GreeterList : FadableBox
 
     private void start_session ()
     {
-        if (!ArcticaGreeter.singleton.start_session (get_lightdm_session (), background))
+        var greeter = new ArcticaGreeter ();
+        if (!greeter.start_session (get_lightdm_session (), background))
         {
             show_message (_("Failed to start session"), true);
             start_authentication ();
diff --git a/src/main-window.vala b/src/main-window.vala
index 993e43e..d7fe6f0 100644
--- a/src/main-window.vala
+++ b/src/main-window.vala
@@ -40,7 +40,7 @@ public class MainWindow : Gtk.Window
     public ListStack stack;
 
     // Menubar is smaller, but with shadow, we reserve more space
-    public const int MENUBAR_HEIGHT = 32;
+    public const int MENUBAR_HEIGHT = 40;
 
     construct
     {
@@ -75,6 +75,8 @@ public class MainWindow : Gtk.Window
             shadow_style = "background-image: url('%s');
                             background-repeat: repeat;".printf(shadow_path);
         }
+        /* Disable the shadow image, we will use CSS instead. */
+        /*
         try
         {
             var style = new Gtk.CssProvider ();
@@ -89,6 +91,7 @@ public class MainWindow : Gtk.Window
         {
             debug ("Internal error loading menubox style: %s", e.message);
         }
+        */
         menubox.set_size_request (-1, MENUBAR_HEIGHT);
         menubox.show ();
         menualign.show ();
@@ -159,7 +162,8 @@ public class MainWindow : Gtk.Window
         only_on_monitor = AGSettings.get_string(AGSettings.KEY_ONLY_ON_MONITOR);
         monitor_setting_ok = only_on_monitor == "auto";
 
-        if (ArcticaGreeter.singleton.test_mode)
+        var greeter = new ArcticaGreeter ();
+        if (greeter.test_mode)
         {
             /* Simulate an 800x600 monitor to the left of a 640x480 monitor */
             monitors = new List<Monitor> ();
@@ -375,6 +379,7 @@ public class MainWindow : Gtk.Window
             }
         }
 
+        var greeter = new ArcticaGreeter ();
         switch (event.keyval)
         {
         case Gdk.Key.Escape:
@@ -434,14 +439,14 @@ public class MainWindow : Gtk.Window
             }
             return true;
         case Gdk.Key.z:
-            if (ArcticaGreeter.singleton.test_mode && (event.state & Gdk.ModifierType.MOD1_MASK) != 0)
+            if (greeter.test_mode && (event.state & Gdk.ModifierType.MOD1_MASK) != 0)
             {
                 show_shutdown_dialog (ShutdownDialogType.SHUTDOWN);
                 return true;
             }
             break;
         case Gdk.Key.Z:
-            if (ArcticaGreeter.singleton.test_mode && (event.state & Gdk.ModifierType.MOD1_MASK) != 0)
+            if (greeter.test_mode && (event.state & Gdk.ModifierType.MOD1_MASK) != 0)
             {
                 show_shutdown_dialog (ShutdownDialogType.RESTART);
                 return true;
diff --git a/src/menubar.vala b/src/menubar.vala
index a2b6b99..a417a03 100644
--- a/src/menubar.vala
+++ b/src/menubar.vala
@@ -68,7 +68,6 @@ private class IndicatorMenuItem : Gtk.MenuItem
 public class MenuBar : Gtk.MenuBar
 {
     public Background? background { get; construct; default = null; }
-    public bool high_contrast { get; private set; default = false; }
     public Gtk.Window? keyboard_window { get; private set; default = null; }
     public Gtk.AccelGroup? accel_group { get; construct; }
 
@@ -83,16 +82,57 @@ public class MenuBar : Gtk.MenuBar
     {
         if (background != null)
         {
+            /* Disable background drawing to see how it changes the visuals. */
+            /*
             int x, y;
             background.translate_coordinates (this, 0, 0, out x, out y);
             c.save ();
             c.translate (x, y);
             background.draw_full (c, Background.DrawFlags.NONE);
             c.restore ();
+            */
         }
 
-        c.set_source_rgb (0.1, 0.1, 0.1);
-        c.paint_with_alpha (0.4);
+        /* Get the style and dimensions. */
+        var style_ctx = this.get_style_context ();
+
+        var w = this.get_allocated_width ();
+        var h = this.get_allocated_height ();
+
+        /* Add a group. */
+        c.push_group ();
+
+        /* Draw the background normally. */
+        style_ctx.render_background (c, 0, 0, w, h);
+
+        /* Draw the frame normally. */
+        style_ctx.render_frame (c, 0, 0, w, h);
+
+        /* Go back to the original widget. */
+        c.pop_group_to_source ();
+
+        var agsettings = new AGSettings ();
+        if (agsettings.high_contrast) {
+            /*
+             * In case the high contrast mode is enabled, do not add any
+             * transparency. While the GTK theme might define one (even though
+             * it better should not, given that we are also switching to a
+             * high contrast theme), we certainly do not want to make the look
+             * fuzzy.
+             */
+             c.paint ();
+        }
+        else {
+            /*
+             * And finally repaint it with additional transparency.
+             * Note that most GTK styles already define a transparency for OSD
+             * menus. We want to have something more transparent, but also
+             * make sure that it is not too transparent, so do not choose a
+             * value that is too low here - certainly not your desired final
+             * alpha value.
+             */
+            c.paint_with_alpha (AGSettings.get_double (AGSettings.KEY_MENUBAR_ALPHA));
+        }
 
         foreach (var child in get_children ())
         {
@@ -102,43 +142,131 @@ public class MenuBar : Gtk.MenuBar
         return false;
     }
 
+    public static void add_style_class (Gtk.Widget widget)
+    {
+        /*
+         * Add style context class osd, which makes the widget respect the GTK
+         * style definitions for this type of elements.
+         */
+        var ctx = widget.get_style_context ();
+        ctx.add_class ("osd");
+    }
+
     /* Due to LP #973922 the keyboard has to be loaded after the main window
      * is shown and given focus. Therefore we don't enable the active state
      * until now.
      */
     public void set_keyboard_state ()
     {
-        if (!ArcticaGreeter.singleton.test_mode)
+        var greeter = new ArcticaGreeter ();
+        if (!greeter.test_mode)
             onscreen_keyboard_item.set_active (AGSettings.get_boolean (AGSettings.KEY_ONSCREEN_KEYBOARD));
     }
 
-    private string default_theme_name;
     private List<Indicator.Object> indicator_objects;
     private Gtk.CheckMenuItem high_contrast_item;
+    private Gtk.CheckMenuItem big_font_item;
     private Pid keyboard_pid = 0;
     private Pid reader_pid = 0;
     private Gtk.CheckMenuItem onscreen_keyboard_item;
 
     construct
     {
-        Gtk.Settings.get_default ().get ("gtk-theme-name", out default_theme_name);
+        add_style_class (this);
+
+        /* Add shadow. */
+        var shadow_style = new Gtk.CssProvider ();
+        shadow_style.load_from_data ("* { box-shadow: 0px 0px 5px 5px #000000; }", -1);
+        this.get_style_context ().add_provider (shadow_style,
+                                                Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);
 
         pack_direction = Gtk.PackDirection.RTL;
 
         if (AGSettings.get_boolean (AGSettings.KEY_SHOW_HOSTNAME))
         {
-            var label = new Gtk.Label (Posix.utsname ().nodename);
-            label.show ();
-            var hostname_item = new Gtk.MenuItem ();
-            hostname_item.add (label);
-            hostname_item.sensitive = false;
-            hostname_item.right_justified = true;
-            hostname_item.show ();
+            var hostname_item = new Gtk.MenuItem.with_label (Posix.utsname ().nodename);
             append (hostname_item);
+            hostname_item.show ();
+
+            /*
+             * Even though this (menu) item is insensitive, we want its label
+             * text to have the sensitive color as to not look out of place
+             * and difficult to read.
+             *
+             * There's a really weird bug that leads to always fetch the
+             * sensitive color after the widget (menuitem in this case) has
+             * been set to insensitive once - at least in this constructor.
+             *
+             * I haven't found a way to fix that, or, for that matter, what is
+             * actually causing the issue. Even waiting on the main event loop
+             * until all events are processed didn't help.
+             *
+             * We'll work around this issue by fetching the color before
+             * setting the widget to insensitive and call it proper.
+             */
+            var insensitive_override_style = new Gtk.CssProvider ();
+
+            /*
+             * First, fetch the associated GtkStyleContext and save the state,
+             * we'll override the state later on.
+             */
+            var hostname_item_ctx = hostname_item.get_style_context ();
+            hostname_item_ctx.save ();
+
+            try {
+                /* Get the actual color. */
+                var sensitive_color = hostname_item_ctx.get_color (Gtk.StateFlags.NORMAL);
+                debug ("Directly fetched sensitive color: %s", sensitive_color.to_string ());
+
+                insensitive_override_style.load_from_data ("*:disabled { color: %s; }".printf(sensitive_color.to_string ()), -1);
+            }
+            catch (Error e)
+            {
+                debug ("Internal error loading hostname menu item text color: %s", e.message);
+            }
+            finally {
+                /*
+                 * Restore the context, which we might have changed through the
+                 * previous get_color () call.
+                 */
+                hostname_item_ctx.restore ();
+            }
+
+            try {
+                /* And finally override the insensitive color. */
+                hostname_item_ctx.add_provider (insensitive_override_style,
+                                                Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);
+
+                /*
+                 * Just overriding the color for the Gtk.MenuItem widget
+                 * doesn't help, we'll also apply it to the children.
+                 *
+                 * In theory, we could just use the get_child () method to
+                 * fetch the only child we should ever have on that widget,
+                 * namely a GtkAccelLabel, but that isn't future-proof enough,
+                 * especially if that is ever extended into having a submenu.
+                 *
+                 * Thus, iterate over all children and override the style for
+                 * all of them.
+                 */
+                if (gtk_is_container (hostname_item)) {
+                    var children = hostname_item.get_children ();
+                    foreach (Gtk.Widget element in children) {
+                        var child_ctx = element.get_style_context ();
+                        debug ("Adding override style provider to child widget %s", element.name);
+                        child_ctx.add_provider (insensitive_override_style,
+                                                Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);
+                    }
+                }
+            }
+            catch (Error e)
+            {
+                debug ("Internal error overriding hostname menu item text color: %s", e.message);
+            }
 
-            /* Hack to get a label showing on the menubar */
-            var fg = label.get_style_context ().get_color (Gtk.StateFlags.NORMAL);
-            label.override_color (Gtk.StateFlags.INSENSITIVE, fg);
+            hostname_item.set_sensitive (false);
+
+            hostname_item.set_right_justified (true);
         }
 
         /* Prevent dragging the window by the menubar */
@@ -155,7 +283,8 @@ public class MenuBar : Gtk.MenuBar
 
         setup_indicators ();
 
-        ArcticaGreeter.singleton.starting_session.connect (cleanup);
+        var greeter = new ArcticaGreeter ();
+        greeter.starting_session.connect (cleanup);
     }
 
     private void close_pid (ref Pid pid)
@@ -233,7 +362,19 @@ public class MenuBar : Gtk.MenuBar
         high_contrast_item.add_accelerator ("activate", accel_group, Gdk.Key.h, Gdk.ModifierType.CONTROL_MASK, Gtk.AccelFlags.VISIBLE);
         high_contrast_item.show ();
         submenu.append (high_contrast_item);
-        high_contrast_item.set_active (AGSettings.get_boolean (AGSettings.KEY_HIGH_CONTRAST));
+        var agsettings = new AGSettings ();
+        debug ("Initializing high contrast menu item to state %s", agsettings.high_contrast.to_string ());
+        high_contrast_item.set_active (agsettings.high_contrast);
+
+/* Hide the Big Font feature until it's available.
+        big_font_item = new Gtk.CheckMenuItem.with_label (_("Big Font"));
+        big_font_item.toggled.connect (big_font_toggled_cb);
+        big_font_item.add_accelerator ("activate", accel_group, Gdk.Key.b, Gdk.ModifierType.CONTROL_MASK, Gtk.AccelFlags.VISIBLE);
+        big_font_item.show ();
+        submenu.append (big_font_item);
+*/
+
+        big_font_item.set_active (agsettings.big_font);
         var item = new Gtk.CheckMenuItem.with_label (_("Screen Reader"));
         item.toggled.connect (screen_reader_toggled_cb);
         item.add_accelerator ("activate", accel_group, Gdk.Key.s, Gdk.ModifierType.SUPER_MASK | Gdk.ModifierType.MOD1_MASK, Gtk.AccelFlags.VISIBLE);
@@ -293,7 +434,8 @@ public class MenuBar : Gtk.MenuBar
 
     private void load_indicator (string indicator_name)
     {
-        if (!ArcticaGreeter.singleton.test_mode)
+        var greeter = new ArcticaGreeter ();
+        if (!greeter.test_mode)
         {
             if (indicator_name == "ug-accessibility")
             {
@@ -440,13 +582,14 @@ public class MenuBar : Gtk.MenuBar
 
     private void high_contrast_toggled_cb (Gtk.CheckMenuItem item)
     {
-        var settings = Gtk.Settings.get_default ();
-        if (item.active)
-            settings.set ("gtk-theme-name", "HighContrastInverse");
-        else
-            settings.set ("gtk-theme-name", default_theme_name);
-        high_contrast = item.active;
-        AGSettings.set_boolean (AGSettings.KEY_HIGH_CONTRAST, high_contrast);
+        var agsettings = new AGSettings ();
+        agsettings.high_contrast = item.active;
+    }
+
+    private void big_font_toggled_cb (Gtk.CheckMenuItem item)
+    {
+        var agsettings = new AGSettings ();
+        agsettings.big_font = item.active;
     }
 
     private void screen_reader_toggled_cb (Gtk.CheckMenuItem item)
@@ -484,7 +627,8 @@ public class MenuBar : Gtk.MenuBar
                 // this is not racy with orca startup, it is racy with whether
                 // orca will read the first character or not out loud.  Hence
                 // why we do both.  Ideally this would be fixed in orca itself.
-                ArcticaGreeter.singleton.orca_needs_kick = true;
+                var greeter = new ArcticaGreeter ();
+                greeter.orca_needs_kick = true;
                 Timeout.add_seconds (1, () => {
                     Signal.emit_by_name ((get_toplevel () as Gtk.Window).get_focus ().get_accessible (), "focus-event", true);
                     return false;
diff --git a/src/prompt-box.vala b/src/prompt-box.vala
index 1a0007f..2180c70 100644
--- a/src/prompt-box.vala
+++ b/src/prompt-box.vala
@@ -208,7 +208,21 @@ public class PromptBox : FadableBox
             debug ("Internal error loading font style (%s, %dpt): %s", font_family, font_size+2, e.message);
         }
 
-        name_label.override_color (Gtk.StateFlags.NORMAL, { 1.0f, 1.0f, 1.0f, 1.0f });
+        var agsettings = new AGSettings ();
+        try
+        {
+            var color_provider = new Gtk.CssProvider ();
+            var css = "* { color: rgba(255, 255, 255, 1.0); }\n" +
+                      ".high_contrast { color: rgba (0, 0, 0, 1.0); }";
+            color_provider.load_from_data (css, -1);
+            style_ctx.add_provider (color_provider,
+                                    Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);
+        }
+        catch (Error e)
+        {
+            debug ("Internal error setting color on name label: %s", e.message);
+        }
+
         name_label.valign = Gtk.Align.START;
         name_label.vexpand = true;
         name_label.yalign = 0.5f;
@@ -236,7 +250,40 @@ public class PromptBox : FadableBox
         name_grid.attach (align, COL_NAME_MESSAGE, ROW_NAME, 1, 1);
 
         option_button = new FlatButton ();
-        option_button.get_style_context ().add_class ("option-button");
+        var option_button_ctx = option_button.get_style_context ();
+        option_button_ctx.add_class ("option-button");
+
+        try {
+            /*
+             * Override background for both high-contrast and normal modes.
+             * Note that we have to use CSS selectors here, since this code
+             * is only executed once.
+             */
+            var background_style = new Gtk.CssProvider ();
+            background_style.load_from_data ("button.flat.option-button.high_contrast {\n" +
+                                             "   background-color: %s;\n".printf("rgba(0,0,0,1.0)") +
+                                             "   background-image: none;\n" +
+                                             "}\n" +
+                                             "button.flat.option-button:hover:not(.high_contrast), " +
+                                             "button.flat.option-button:active:not(.high_contrast), " +
+                                             "button.flat.option-button:hover:active:not(.high_contrast) {\n"+
+                                             "   background-color: %s;\n".printf("rgba(255,255,255,0.5)")+
+                                             "   background-image: none;"+
+                                             "}\n" +
+                                             "button.flat.option-button:hover.high_contrast," +
+                                             "button.flat.option-button:active.high_contrast," +
+                                             "button.flat.option-button:hover:active.high_contrast {\n" +
+                                             "   background-color:%s;\n".printf("rgba(70, 70, 70, 1.0)") +
+                                             "   background-image: none;" +
+                                             "}\n", -1);
+            option_button_ctx.add_provider (background_style,
+                                            Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);
+        }
+        catch (Error e)
+        {
+            debug ("Internal error loading option button background style: %s", e.message);
+        }
+
         option_button.hexpand = true;
         option_button.halign = Gtk.Align.END;
         option_button.valign = Gtk.Align.START;
@@ -388,6 +435,7 @@ public class PromptBox : FadableBox
     public void clear ()
     {
         prompt_visibility = PromptVisibility.HIDDEN;
+        active_indicator.expanded = false;
 
         /* Hold a ref while removing the prompt widgets -
          * if we just do w.destroy() we get this warning:
@@ -452,6 +500,7 @@ public class PromptBox : FadableBox
         {
         case PromptVisibility.HIDDEN:
             w.hide ();
+            active_indicator.expanded = false;
             break;
         case PromptVisibility.FADING:
             var f = w as Fadable;
@@ -460,10 +509,12 @@ public class PromptBox : FadableBox
                 f.fade_in ();
             else
                 w.show ();
+            active_indicator.expanded = true;
             break;
         case PromptVisibility.SHOWN:
             w.show ();
             w.sensitive = true;
+            active_indicator.expanded = true;
             break;
         }
     }
@@ -473,6 +524,7 @@ public class PromptBox : FadableBox
         prompt_visibility = PromptVisibility.FADING;
         show ();
         foreach_prompt_widget ((w) => { update_prompt_visibility (w); });
+        active_indicator.expanded = true;
     }
 
     public void show_prompts ()
@@ -480,6 +532,7 @@ public class PromptBox : FadableBox
         prompt_visibility = PromptVisibility.SHOWN;
         show ();
         foreach_prompt_widget ((w) => { update_prompt_visibility (w); });
+        active_indicator.expanded = true;
     }
 
     protected void attach_item (Gtk.Widget w, bool add_style_class = true)
@@ -713,6 +766,7 @@ public class PromptBox : FadableBox
 private class ActiveIndicator : Gtk.Image
 {
     public bool active { get; set; }
+    public bool expanded { get; set; }
     public const int WIDTH = 8;
     public const int HEIGHT = 7;
 
@@ -722,12 +776,16 @@ private class ActiveIndicator : Gtk.Image
         try
         {
             pixbuf = new Gdk.Pixbuf.from_file (filename);
+            pixbuf_changed_helper ();
         }
         catch (Error e)
         {
             debug ("Could not load active image: %s", e.message);
         }
         notify["active"].connect (() => { queue_draw (); });
+        notify["expanded"].connect (() => { notify_expanded (); });
+        notify["pixbuf"].connect ((s, p) => { notify_pixbuf_changed (s, p); });
+        this.style_updated.connect ((w) => { handle_style_updated (w); });
         xalign = 0.0f;
     }
 
@@ -747,6 +805,132 @@ private class ActiveIndicator : Gtk.Image
     {
         if (!active)
             return false;
+
         return base.draw (c);
     }
+
+    private void notify_pixbuf_changed (Object src, ParamSpec prop) {
+        assert ("pixbuf" == prop.name);
+
+        if (!(this.swapping_)) {
+            pixbuf_changed_helper ();
+        }
+    }
+
+    private void pixbuf_changed_helper () {
+        /* Copy the new pixbuf. */
+        this.pixbuf_orig_ = this.pixbuf.copy ();
+        this.pixbuf.copy_options (this.pixbuf_orig_);
+        this.pixbuf_inverted_ = this.pixbuf.copy ();
+        this.pixbuf.copy_options (this.pixbuf_inverted_);
+
+        /* Invert the new pixbuf. */
+        invert_pixbuf ();
+
+        if (this.inverted_) {
+            this.swapping_ = true;
+            this.pixbuf = this.pixbuf_inverted_;
+            this.swapping_ = false;
+        }
+    }
+
+    private void handle_style_updated (Gtk.Widget widget) {
+        var style_ctx = this.get_style_context ();
+        if (style_ctx.has_class ("high_contrast")) {
+            if ((!(this.inverted_)) && (this.expanded)) {
+                this.swapping_ = true;
+                this.pixbuf = this.pixbuf_inverted_;
+                this.inverted_ = true;
+                this.swapping_ = false;
+            }
+        }
+        else {
+            if (this.inverted_) {
+                this.swapping_ = true;
+                this.pixbuf = this.pixbuf_orig_;
+                this.inverted_ = false;
+                this.swapping_ = false;
+            }
+        }
+    }
+
+    private void invert_pixbuf () {
+        assert (Gdk.Colorspace.RGB == this.pixbuf_inverted_.get_colorspace ());
+        var sample_size = this.pixbuf_inverted_.get_bits_per_sample ();
+        var alpha = this.pixbuf_inverted_.get_has_alpha ();
+        var channels = this.pixbuf_inverted_.get_n_channels ();
+
+        assert (((4 == channels) && (alpha)) ||
+                (3 == channels));
+
+        /*
+         * Fun fact: we don't need to decompose the actual colors. Since
+         * the inversion is just a simple XOR operation, we can just
+         * invert all the bits minus the alpha value.
+         */
+        assert (1 <= sample_size);
+
+        var rowstride = this.pixbuf_inverted_.get_rowstride ();
+        var col_bytes = (((channels * sample_size) + 7) / 8);
+        var row_bytes = (this.pixbuf_inverted_.width * col_bytes);
+        unowned var pixels = this.pixbuf_inverted_.get_pixels ();
+        assert (pixels != null);
+        size_t color_bits = channels;
+        if (alpha) {
+            --color_bits;
+        }
+        color_bits *= sample_size;
+        for (size_t i = 0; i < this.pixbuf_inverted_.height; (++i)) {
+            for (size_t y = 0; y < this.pixbuf_inverted_.width; (++y)) {
+                /* Invert full bytes first. */
+                for (size_t x = 0; x < (color_bits / 8); (++(x))) {
+                    pixels[(i * rowstride) + (y * col_bytes) + (x)] ^= (~(0));
+                }
+
+                /*
+                 * And now, invert the last actual color bits minus alpha
+                 * and padding.
+                 */
+                uint8 rest = (uint8) (color_bits % 8);
+                if (0 < rest) {
+                    uint8 mask = (~(0));
+                    mask <<= (8 - rest);
+                    pixels[(i * rowstride) + (y * col_bytes) + (color_bits / 8)] ^= mask;
+                }
+            }
+        }
+    }
+
+    private void notify_expanded () {
+        if (!(this.expanded)) {
+            /*
+             * In non-expanded form, we always want to have the original
+             * look.
+             */
+            if (this.inverted_) {
+                this.swapping_ = true;
+                this.pixbuf = this.pixbuf_orig_;
+                this.inverted_ = false;
+                this.swapping_ = false;
+            }
+        }
+        else {
+            /*
+             * In expanded form, we want to restore the inverted form iff the
+             * high contrast mode is enabled.
+             */
+            var agsettings = new AGSettings ();
+            if ((!(this.inverted_)) && (agsettings.high_contrast)) {
+                this.swapping_ = true;
+                this.pixbuf = this.pixbuf_inverted_;
+                this.inverted_ = true;
+                this.swapping_ = false;
+            }
+        }
+    }
+
+    private bool inverted_ = false;
+    private bool swapping_ = false;
+    private Gdk.Pixbuf? pixbuf_orig_ = null;
+    private Gdk.Pixbuf? pixbuf_inverted_ = null;
 }
diff --git a/src/session-list.vala b/src/session-list.vala
index 820b4c6..290a7af 100644
--- a/src/session-list.vala
+++ b/src/session-list.vala
@@ -44,7 +44,8 @@ public class SessionPrompt : PromptBox
 
         box = new ToggleBox (default_session, session);
 
-        if (ArcticaGreeter.singleton.test_mode)
+        var greeter = new ArcticaGreeter ();
+        if (greeter.test_mode)
         {
             box.add_item ("gnome", "GNOME", SessionList.get_badge ("gnome"));
             box.add_item ("kde", "KDE", SessionList.get_badge ("kde"));
diff --git a/src/settings.vala b/src/settings.vala
index 701d5a1..af753ce 100644
--- a/src/settings.vala
+++ b/src/settings.vala
@@ -2,6 +2,7 @@
  *
  * Copyright (C) 2011,2012 Canonical Ltd
  * Copyright (C) 2015,2017 Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
+ * Copyright (C) 2022 Mihai Moldovan <ionic@ionic.de>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
@@ -20,7 +21,8 @@
  *          Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
  */
 
-public class AGSettings
+[SingleInstance]
+public class AGSettings : Object
 {
     public const string KEY_BACKGROUND = "background";
     public const string KEY_BACKGROUND_COLOR = "background-color";
@@ -29,6 +31,7 @@ public class AGSettings
     public const string KEY_SHOW_HOSTNAME = "show-hostname";
     public const string KEY_LOGO = "logo";
     public const string KEY_THEME_NAME = "theme-name";
+    public const string KEY_HIGH_CONTRAST_THEME_NAME = "high-contrast-theme-name";
     public const string KEY_ICON_THEME_NAME = "icon-theme-name";
     public const string KEY_FONT_NAME = "font-name";
     public const string KEY_XFT_ANTIALIAS = "xft-antialias";
@@ -37,6 +40,7 @@ public class AGSettings
     public const string KEY_XFT_RGBA = "xft-rgba";
     public const string KEY_ONSCREEN_KEYBOARD = "onscreen-keyboard";
     public const string KEY_HIGH_CONTRAST = "high-contrast";
+    public const string KEY_BIG_FONT = "big-font";
     public const string KEY_SCREEN_READER = "screen-reader";
     public const string KEY_PLAY_READY_SOUND = "play-ready-sound";
     public const string KEY_INDICATORS = "indicators";
@@ -49,6 +53,8 @@ public class AGSettings
     public const string KEY_TOGGLEBOX_FONT_FGCOLOR = "togglebox-font-fgcolor";
     public const string KEY_TOGGLEBOX_BUTTON_BGCOLOR = "togglebox-button-bgcolor";
     public const string KEY_ENABLE_HIDPI = "enable-hidpi";
+    public const string KEY_MENUBAR_ALPHA = "menubar-alpha";
+
 
     public static bool get_boolean (string key)
     {
@@ -105,5 +111,68 @@ public class AGSettings
         return gsettings.set_strv (key, value);
     }
 
+    public AGSettings ()
+    {
+    }
+
+    construct {
+        Gtk.Settings.get_default ().get ("gtk-theme-name", out this.default_theme_name_);
+        /*
+        debug ("Fetched default theme name in construct: %s", this.default_theme_name_);
+        */
+    }
+
+    public bool high_contrast {
+        get {
+            return this.high_contrast_;
+        }
+
+        set {
+            debug ("Called high contrast setter with value %s", value.to_string ());
+            this.high_contrast_ = value;
+
+            /* Also sync back to dconf, so that this state is persistent. */
+            set_boolean (AGSettings.KEY_HIGH_CONTRAST, value);
+
+            var greeter = new ArcticaGreeter ();
+            greeter.switch_contrast (value);
+
+            var settings = Gtk.Settings.get_default ();
+            if (value)
+            {
+                /*
+                debug ("Switching GTK Theme to high contrast theme \"%s\"", AGSettings.get_string (AGSettings.KEY_HIGH_CONTRAST_THEME_NAME));
+                */
+                settings.set ("gtk-theme-name", AGSettings.get_string (AGSettings.KEY_HIGH_CONTRAST_THEME_NAME));
+            }
+            else
+            {
+                /*
+                debug ("Switching GTK Theme to default theme \"%s\"", this.default_theme_name_);
+                */
+                settings.set ("gtk-theme-name", this.default_theme_name_);
+            }
+        }
+    }
+
+    public bool big_font {
+        get {
+            return this.big_font_;
+        }
+
+        set {
+            this.big_font_ = value;
+
+            /* Also sync back to dconf, so that this state is persistent. */
+            set_boolean (AGSettings.KEY_BIG_FONT, value);
+
+            var greeter = new ArcticaGreeter ();
+            greeter.switch_font (value);
+        }
+    }
+
     private const string SCHEMA = "org.ArcticaProject.arctica-greeter";
+    private bool high_contrast_ = AGSettings.get_boolean (AGSettings.KEY_HIGH_CONTRAST);
+    private bool big_font_ = AGSettings.get_boolean (AGSettings.KEY_BIG_FONT);
+    private string default_theme_name_;
 }
diff --git a/src/toggle-box.vala b/src/toggle-box.vala
index 5502c1d..518275f 100644
--- a/src/toggle-box.vala
+++ b/src/toggle-box.vala
@@ -65,13 +65,26 @@ public class ToggleBox : Gtk.Box
             /* Tighten padding on buttons to not be so large, default color scheme for buttons */
             var style = new Gtk.CssProvider ();
             style.load_from_data ("* {padding: 8px;}\n"+
-                                  "GtkButton {\n"+
+                                  "GtkButton, button {\n"+
                                   "   background-color: %s;\n".printf("rgba(0,0,0,0)")+
                                   "   background-image: none;"+
                                   "}\n"+
-                                  ".button:hover,\n"+
-                                  ".button:hover:active {\n"+
+                                  "button:hover,\n"+
+                                  "button:active,\n" +
+                                  "button:hover:active,\n" +
+                                  "button.selected {\n"+
                                   "   background-color: %s;\n".printf(AGSettings.get_string (AGSettings.KEY_TOGGLEBOX_BUTTON_BGCOLOR))+
+                                  "}\n" +
+                                  "button.high_contrast {\n" +
+                                  "   background-color: %s;\n".printf ("rgba(70, 70, 70, 1.0)") +
+                                  "   background-image: none;\n" +
+                                  "   border-color: %s\n;".printf ("rgba(0, 0, 0, 1.0)") +
+                                  "}\n" +
+                                  "button.high_contrast:hover,\n" +
+                                  "button.high_contrast:active,\n" +
+                                  "button.high_contrast:hover:active,\n" +
+                                  "button.high_contrast.selected {\n" +
+                                  "   background-color: %s;\n".printf ("rgba(0, 0, 0, 1.0)") +
                                   "}\n", -1);
             button.get_style_context ().add_provider (style, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);
         }
@@ -113,9 +126,8 @@ public class ToggleBox : Gtk.Box
         selected_button = button;
         selected_key = selected_button.get_data<string> ("toggle-list-key");
 
-        var bg_color = Gdk.RGBA ();
-        bg_color.parse (AGSettings.get_string (AGSettings.KEY_TOGGLEBOX_BUTTON_BGCOLOR));
-        selected_button.override_background_color(Gtk.StateFlags.NORMAL, bg_color);
+        /* Handle color via CSS. */
+        selected_button.get_style_context ().add_class ("selected");
     }
 
     private Gtk.Button make_button (string key, string name_in, Gdk.Pixbuf? icon)
@@ -140,7 +152,24 @@ public class ToggleBox : Gtk.Box
         }
 
         var label = new Gtk.Label (null);
-        label.set_markup ("<span font=\"%s %d\" fgcolor=\"%s\">%s</span>".printf (font_family, font_size+2, AGSettings.get_string (AGSettings.KEY_TOGGLEBOX_FONT_FGCOLOR), name));
+        /* Font and other properties are being handled via CSS. */
+        label.set_text (name);
+        try {
+            var style = new Gtk.CssProvider ();
+            style.load_from_data ("label {\n" +
+                                  "   font-family: \"%s\", sans-serif;\n".printf (font_family) +
+                                  "   font-size: %d;\n".printf (font_size + 2) +
+                                  "   color: %s;\n".printf (AGSettings.get_string (AGSettings.KEY_TOGGLEBOX_FONT_FGCOLOR)) +
+                                  "}\n" +
+                                  "label.high_contrast {\n" +
+                                  "   color: %s;\n".printf ("rgba(255, 255, 255, 1.0)") +
+                                  "}\n", -1);
+            label.get_style_context ().add_provider (style, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);
+        }
+        catch (Error e)
+        {
+            debug ("Internal error loading session chooser label style: %s", e.message);
+        }
         label.halign = Gtk.Align.START;
         hbox.pack_start (label, true, true, 0);
 
diff --git a/src/user-list.vala b/src/user-list.vala
index 0991703..9f4b265 100644
--- a/src/user-list.vala
+++ b/src/user-list.vala
@@ -73,7 +73,8 @@ public class UserList : GreeterList
         {
             show_hidden_users_ = value;
 
-            if (ArcticaGreeter.singleton.test_mode)
+            var greeter = new ArcticaGreeter ();
+            if (greeter.test_mode)
             {
                 if (value)
                     add_user ("hidden", "Hidden User", null, false, false, null);
@@ -147,7 +148,8 @@ public class UserList : GreeterList
 
     construct
     {
-        menubar.notify["high-contrast"].connect (() => { change_background (); });
+        var agsettings = new AGSettings ();
+        agsettings.notify["high-contrast"].connect (() => { change_background (); });
         entry_displayed_start.connect (() => { change_background (); });
         entry_displayed_done.connect (() => { change_background (); });
 
@@ -166,8 +168,9 @@ public class UserList : GreeterList
 
         connect_to_lightdm ();
 
-        if (!ArcticaGreeter.singleton.test_mode &&
-            ArcticaGreeter.singleton.show_remote_login_hint ())
+        var greeter = new ArcticaGreeter ();
+        if (!greeter.test_mode &&
+            greeter.show_remote_login_hint ())
             remote_logon_service_watch = Bus.watch_name (BusType.SESSION,
                                             "org.ArcticaProject.RemoteLogon",
                                             BusNameWatcherFlags.AUTO_START,
@@ -390,7 +393,8 @@ public class UserList : GreeterList
         remote_logon_service = null;
 
         /* provide a fallback manual login option */
-        if (ArcticaGreeter.singleton.hide_users_hint ()) {
+        var greeter = new ArcticaGreeter ();
+        if (greeter.hide_users_hint ()) {
             add_manual_entry();
             set_active_entry ("*other");
         }
@@ -443,10 +447,11 @@ public class UserList : GreeterList
         else
         {
             var login_success = false;
+            var greeter = new ArcticaGreeter ();
             try
             {
                 var url = url_from_remote_loding_server_list_name (selected_entry.id);
-                if (ArcticaGreeter.singleton.test_mode)
+                if (greeter.test_mode)
                 {
                     if (password_field.text == "password")
                     {
@@ -528,7 +533,8 @@ public class UserList : GreeterList
         sensitive = false;
         will_clear = true;
         greeter_authenticating_user = selected_entry.id;
-        if (ArcticaGreeter.singleton.test_mode)
+        var greeter = new ArcticaGreeter ();
+        if (greeter.test_mode)
         {
             Gtk.Entry field = current_remote_fields.get ("password") as Gtk.Entry;
             test_is_authenticated = field.text == "password";
@@ -539,7 +545,7 @@ public class UserList : GreeterList
         }
         else
         {
-            ArcticaGreeter.singleton.authenticate_remote (get_lightdm_session (), null);
+            greeter.authenticate_remote (get_lightdm_session (), null);
             remote_logon_service.set_last_used_server.begin (currently_browsing_server_url, url_from_remote_loding_server_list_name (selected_entry.id));
         }
     }
@@ -576,7 +582,8 @@ public class UserList : GreeterList
                 if (is_supported_remote_session (config_session))
                 {
                     greeter_authenticating_user = selected_entry.id;
-                    ArcticaGreeter.singleton.authenticate_remote (config_session, null);
+                    var greeter = new ArcticaGreeter ();
+                    greeter.authenticate_remote (config_session, null);
                 }
             }
             dialog.destroy ();
@@ -587,7 +594,8 @@ public class UserList : GreeterList
     private bool change_background_timeout_cb ()
     {
         string? new_background_file = null;
-        if (menubar.high_contrast || !AGSettings.get_boolean (AGSettings.KEY_DRAW_USER_BACKGROUNDS))
+        var agsettings = new AGSettings ();
+        if (agsettings.high_contrast || !AGSettings.get_boolean (AGSettings.KEY_DRAW_USER_BACKGROUNDS))
             new_background_file = null;
         else if (selected_entry is UserPromptBox)
             new_background_file = (selected_entry as UserPromptBox).background;
@@ -635,7 +643,8 @@ public class UserList : GreeterList
 
     private void entry_selected_cb (string? username)
     {
-        ArcticaGreeter.singleton.set_state ("last-user", username);
+        var greeter = new ArcticaGreeter ();
+        greeter.set_state ("last-user", username);
         if (selected_entry is UserPromptBox)
             session = (selected_entry as UserPromptBox).session;
         else
@@ -777,9 +786,10 @@ public class UserList : GreeterList
                     else if (field.type == "email")
                     {
                         string[] email_domains;
+                        var greeter = new ArcticaGreeter ();
                         try
                         {
-                            if (ArcticaGreeter.singleton.test_mode)
+                            if (greeter.test_mode)
                                 email_domains = { "canonical.com", "ubuntu.org", "candy.com", "urban.net" };
                             else
                                 yield remote_logon_service.get_cached_domains_for_server (url, out email_domains);
@@ -889,12 +899,13 @@ public class UserList : GreeterList
         will_clear = true;
         unacknowledged_messages = false;
 
+        var greeter = new ArcticaGreeter ();
         foreach (var response in responses)
         {
-            if (ArcticaGreeter.singleton.test_mode)
+            if (greeter.test_mode)
                 test_respond (response);
             else
-                ArcticaGreeter.singleton.respond (response);
+                greeter.respond (response);
         }
     }
 
@@ -904,10 +915,11 @@ public class UserList : GreeterList
 
         unacknowledged_messages = false;
         var is_authenticated = false;
-        if (ArcticaGreeter.singleton.test_mode)
+        var greeter = new ArcticaGreeter ();
+        if (greeter.test_mode)
             is_authenticated = test_is_authenticated;
         else
-            is_authenticated = ArcticaGreeter.singleton.is_authenticated();
+            is_authenticated = greeter.is_authenticated();
 
         /* Finish authentication (again) or restart it */
         if (is_authenticated)
@@ -923,18 +935,21 @@ public class UserList : GreeterList
     {
         var session_chooser = new SessionList (background, menubar, session, default_session);
         session_chooser.session_clicked.connect (session_clicked_cb);
-        ArcticaGreeter.singleton.push_list (session_chooser);
+        var greeter = new ArcticaGreeter ();
+        greeter.push_list (session_chooser);
     }
 
     private void session_clicked_cb (string session)
     {
         this.session = session;
-        ArcticaGreeter.singleton.pop_list ();
+        var greeter = new ArcticaGreeter ();
+        greeter.pop_list ();
     }
 
     private bool should_show_session_badge ()
     {
-        if (ArcticaGreeter.singleton.test_mode)
+        var greeter = new ArcticaGreeter ();
+        if (greeter.test_mode)
             return get_selected_id () != "no-badge";
         else
             return LightDM.get_sessions ().length () > 1;
@@ -962,7 +977,8 @@ public class UserList : GreeterList
 
     private bool is_supported_remote_session (string session_internal_name)
     {
-        if (ArcticaGreeter.singleton.test_mode)
+        var greeter = new ArcticaGreeter ();
+        if (greeter.test_mode)
             return session_internal_name == "rdp";
 
         var found = false;
@@ -1004,13 +1020,14 @@ public class UserList : GreeterList
 
     private void fill_list ()
     {
-        if (ArcticaGreeter.singleton.test_mode)
+        var greeter = new ArcticaGreeter ();
+        if (greeter.test_mode)
             test_fill_list ();
         else
         {
-            default_session = ArcticaGreeter.singleton.default_session_hint ();
-            always_show_manual = ArcticaGreeter.singleton.show_manual_login_hint ();
-            if (!ArcticaGreeter.singleton.hide_users_hint ())
+            default_session = greeter.default_session_hint ();
+            always_show_manual = greeter.show_manual_login_hint ();
+            if (!greeter.hide_users_hint ())
             {
                 var users = LightDM.UserList.get_instance ();
                 users.user_added.connect (user_added_cb);
@@ -1020,7 +1037,7 @@ public class UserList : GreeterList
                     user_added_cb (user);
             }
 
-            if (ArcticaGreeter.singleton.has_guest_account_hint ())
+            if (greeter.has_guest_account_hint ())
             {
                 debug ("Adding guest account entry");
                 offer_guest = true;
@@ -1030,9 +1047,9 @@ public class UserList : GreeterList
             if (!have_entries ())
                 add_manual_entry ();
 
-            var last_user = ArcticaGreeter.singleton.get_state ("last-user");
-            if (ArcticaGreeter.singleton.select_user_hint () != null)
-                set_active_entry (ArcticaGreeter.singleton.select_user_hint ());
+            var last_user = greeter.get_state ("last-user");
+            if (greeter.select_user_hint () != null)
+                set_active_entry (greeter.select_user_hint ());
             else if (last_user != null)
                 set_active_entry (last_user);
         }
@@ -1098,39 +1115,40 @@ public class UserList : GreeterList
     {
         if (selected_entry.id.has_prefix ("*remote_login"))
         {
+            var greeter = new ArcticaGreeter ();
             if ((text == pam_x2go.PROMPT_USER) || (text == pam_freerdp2.PROMPT_USER))
             {
                 Gtk.Entry field = current_remote_fields.get ("username") as Gtk.Entry;
                 var answer = field != null ? field.text : "";
                 debug ("remote_login prompt parsing: username -> %s", answer);
-                ArcticaGreeter.singleton.respond (answer);
+                greeter.respond (answer);
             }
             else if ((text == pam_x2go.PROMPT_PASSWORD) || (text == pam_freerdp2.PROMPT_PASSWORD))
             {
                 Gtk.Entry field = current_remote_fields.get ("password") as Gtk.Entry;
                 var answer = field != null ? field.text : "";
                 debug ("remote_login prompt parsing: password -> <hidden>");
-                ArcticaGreeter.singleton.respond (answer);
+                greeter.respond (answer);
             }
             else if ((text == pam_x2go.PROMPT_HOST) || (text == pam_freerdp2.PROMPT_HOST))
             {
                 var answer = url_from_remote_loding_server_list_name (selected_entry.id);
                 debug ("remote_login prompt parsing: host -> %s", answer);
-                ArcticaGreeter.singleton.respond (answer);
+                greeter.respond (answer);
             }
             else if (text == pam_freerdp2.PROMPT_DOMAIN)
             {
                 Gtk.Entry field = current_remote_fields.get ("domain") as Gtk.Entry;
                 var answer = field != null ? field.text : "";
                 debug ("remote_login prompt parsing: domain -> %s", answer);
-                ArcticaGreeter.singleton.respond (answer);
+                greeter.respond (answer);
             }
             else if (text == pam_x2go.PROMPT_COMMAND)
             {
                 Gtk.Entry field = current_remote_fields.get ("command") as Gtk.Entry;
                 var answer = field != null ? field.text : "";
                 debug ("remote_login prompt parsing: command -> %s", answer);
-                ArcticaGreeter.singleton.respond (answer);
+                greeter.respond (answer);
             }
         }
         else
@@ -1210,7 +1228,8 @@ public class UserList : GreeterList
         {
         }
 
-        if (!ArcticaGreeter.singleton.hide_users_hint())
+        var greeter = new ArcticaGreeter ();
+        if (!greeter.hide_users_hint())
             while (add_test_entry ());
 
         /* add a manual entry if the list of entries is empty initially */
@@ -1221,12 +1240,12 @@ public class UserList : GreeterList
             n_test_entries++;
         }
 
-        offer_guest = ArcticaGreeter.singleton.has_guest_account_hint();
-        always_show_manual = ArcticaGreeter.singleton.show_manual_login_hint();
+        offer_guest = greeter.has_guest_account_hint();
+        always_show_manual = greeter.show_manual_login_hint();
 
         key_press_event.connect (test_key_press_cb);
 
-        if (ArcticaGreeter.singleton.show_remote_login_hint())
+        if (greeter.show_remote_login_hint())
             Timeout.add (1000, () =>
             {
                 RemoteServer[] test_server_list = {};
@@ -1248,7 +1267,7 @@ public class UserList : GreeterList
                 return false;
             });
 
-        var last_user = ArcticaGreeter.singleton.get_state ("last-user");
+        var last_user = greeter.get_state ("last-user");
         if (last_user != null)
             set_active_entry (last_user);
 
diff --git a/src/util.vala b/src/util.vala
new file mode 100644
index 0000000..6b82f50
--- /dev/null
+++ b/src/util.vala
@@ -0,0 +1,28 @@
+/* -*- Mode: Vala; indent-tabs-mode: nil; tab-width: 4 -*-
+ *
+ * Copyright (C) 2011,2012 Canonical Ltd
+ * Copyright (C) 2015-2017 Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
+ * Copyright (C) 2022 Mihai Moldovan <ionic@ionic.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Robert Ancell <robert.ancell@canonical.com>
+ *          Michael Terry <michael.terry@canonical.com>
+ *          Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
+ *          Mihai Moldovan <ionic@ionic.de>
+ */
+
+#if !HAVE_GTK_4_0
+[CCode(cname = "GTK_IS_CONTAINER", cheader_filename="gtk/gtk.h", simple_generics = true, has_target = false)]
+static extern bool gtk_is_container<T> (T widget);
+#endif
diff --git a/tests/arctica-greeter.vala b/tests/arctica-greeter.vala
index 2a6581b..3bcfeb8 100644
--- a/tests/arctica-greeter.vala
+++ b/tests/arctica-greeter.vala
@@ -19,7 +19,8 @@
 
 public const int grid_size = 40;
 
-public class ArcticaGreeter
+[SingleInstance]
+public class ArcticaGreeter : Object
 {
     public static ArcticaGreeter singleton;
 
@@ -27,11 +28,16 @@ public class ArcticaGreeter
     public signal void show_prompt (string text, LightDM.PromptType type);
     public signal void authentication_complete ();
 
-    public bool test_mode = false;
+    public bool test_mode { get; construct; default = false; }
     public bool session_started = false;
     public string last_respond_response;
     public bool orca_needs_kick;
 
+    public ArcticaGreeter (bool test_mode_ = false)
+    {
+        Object (test_mode: test_mode_);
+    }
+
     public bool is_authenticated ()
     {
         return false;
diff --git a/tests/menubar.vala b/tests/menubar.vala
index f222957..4162dc0 100644
--- a/tests/menubar.vala
+++ b/tests/menubar.vala
@@ -19,7 +19,6 @@
 public class MenuBar : Gtk.MenuBar
 {
     public const int HEIGHT = 32;
-    public bool high_contrast { get; private set; default = false; }
 
     public MenuBar (Background bg, Gtk.AccelGroup ag)
     {
diff --git a/tests/test.vala b/tests/test.vala
index b129bfd..9348b82 100644
--- a/tests/test.vala
+++ b/tests/test.vala
@@ -137,6 +137,21 @@ public class Test
         }
     }
 
+    public static void greeter_test_mode ()
+    {
+        var greeter = new ArcticaGreeter ();
+
+        /*
+         * Test that fetching the greeter singleton worked, even though we use
+         * the default value for test mode (false).
+         */
+        GLib.assert (true == greeter.test_mode);
+
+        // And explicitly try to override it, too.
+        greeter = new ArcticaGreeter (false);
+        GLib.assert (true == greeter.test_mode);
+    }
+
     public static void simple_navigation ()
     {
         MainWindow mw = setup ();
@@ -486,11 +501,12 @@ public class Test
         GLib.assert (list.selected_entry.id == "*remote_login*http://rdpdefaultusername2.com*lwola");
         wait_for_scrolling_end (list);
 
-        ArcticaGreeter.singleton.session_started = false;
+        var greeter = new ArcticaGreeter ();
+        greeter.session_started = false;
         pwd = remote_login_entry_password_field (list);
         pwd.text = "password";
         list.selected_entry.respond ({});
-        GLib.assert (ArcticaGreeter.singleton.session_started);
+        GLib.assert (greeter.session_started);
 
         mw.hide ();
     }
@@ -516,7 +532,8 @@ public class Test
         GLib.assert (list.selected_entry.id == "*remote_login*http://rdpdefaultusername2.com*lwola");
         wait_for_scrolling_end (list);
 
-        ArcticaGreeter.singleton.session_started = false;
+        var greeter = new ArcticaGreeter ();
+        greeter.session_started = false;
         pwd = remote_login_entry_password_field (list);
         pwd.text = "delay";
         pwd.activate ();
@@ -650,14 +667,15 @@ public class Test
         username.text = "bar";
         pwd.text = "foobar";
 
-        ArcticaGreeter.singleton.show_prompt("remote login:", LightDM.PromptType.QUESTION);
-        GLib.assert (ArcticaGreeter.singleton.last_respond_response == username.text);
-        ArcticaGreeter.singleton.show_prompt("remote host:", LightDM.PromptType.QUESTION);
-        GLib.assert (ArcticaGreeter.singleton.last_respond_response == "http://coolrdpserver.com");
-        ArcticaGreeter.singleton.show_prompt("domain:", LightDM.PromptType.QUESTION);
-        GLib.assert (ArcticaGreeter.singleton.last_respond_response == domain.text);
-        ArcticaGreeter.singleton.show_prompt("password:", LightDM.PromptType.SECRET);
-        GLib.assert (ArcticaGreeter.singleton.last_respond_response == pwd.text);
+        var greeter = new ArcticaGreeter ();
+        greeter.show_prompt("remote login:", LightDM.PromptType.QUESTION);
+        GLib.assert (greeter.last_respond_response == username.text);
+        greeter.show_prompt("remote host:", LightDM.PromptType.QUESTION);
+        GLib.assert (greeter.last_respond_response == "http://coolrdpserver.com");
+        greeter.show_prompt("domain:", LightDM.PromptType.QUESTION);
+        GLib.assert (greeter.last_respond_response == domain.text);
+        greeter.show_prompt("password:", LightDM.PromptType.SECRET);
+        GLib.assert (greeter.last_respond_response == pwd.text);
 
         mw.hide ();
     }
@@ -690,15 +708,16 @@ public class Test
 
     public static void remote_login_only ()
     {
-        ArcticaGreeter.singleton.test_mode = true;
-        ArcticaGreeter.singleton.session_started = false;
+        var greeter = new ArcticaGreeter ();
+        greeter.test_mode = true;
+        greeter.session_started = false;
 
 	/* this configuration should result in the list containing only the remote login entry,
 	   without any fallback manual entry */
-        ArcticaGreeter.singleton._hide_users_hint = true;
-        ArcticaGreeter.singleton._show_remote_login_hint = true;
-        ArcticaGreeter.singleton._has_guest_account_hint = false;
-        ArcticaGreeter.singleton._show_manual_login_hint = false;
+        greeter._hide_users_hint = true;
+        greeter._show_remote_login_hint = true;
+        greeter._has_guest_account_hint = false;
+        greeter._show_manual_login_hint = false;
 
         MainWindow mw = setup ();
         TestList list = mw.stack.top () as TestList;
@@ -725,14 +744,15 @@ public class Test
 
    public static void manual_login_fallback ()
    {
-        ArcticaGreeter.singleton.test_mode = true;
-        ArcticaGreeter.singleton.session_started = false;
+        var greeter = new ArcticaGreeter ();
+        greeter.test_mode = true;
+        greeter.session_started = false;
 
 	/* this configuration should result in the list containing at least a manual entry */
-        ArcticaGreeter.singleton._hide_users_hint = true;
-        ArcticaGreeter.singleton._show_remote_login_hint = false;
-        ArcticaGreeter.singleton._has_guest_account_hint = false;
-        ArcticaGreeter.singleton._show_manual_login_hint = true;
+        greeter._hide_users_hint = true;
+        greeter._show_remote_login_hint = false;
+        greeter._has_guest_account_hint = false;
+        greeter._show_manual_login_hint = true;
 
         MainWindow mw = setup ();
         TestList list = mw.stack.top () as TestList;
@@ -782,9 +802,9 @@ public class Test
 
         setup_gsettings ();
 
-        ArcticaGreeter.singleton = new ArcticaGreeter();
-        ArcticaGreeter.singleton.test_mode = true;
+        var greeter = new ArcticaGreeter (true);
 
+        GLib.Test.add_func ("/Greeter Test Mode", greeter_test_mode);
         GLib.Test.add_func ("/Simple Navigation", simple_navigation);
         GLib.Test.add_func ("/Remote Login", remote_login);
         GLib.Test.add_func ("/Remote Login duplicate entries", remote_login_duplicate_entries);