Use wayland protocol to show monitor labels

data/Display.css

@@ -143,3 +143,13 @@ display-widget.disabled button.flat.image-button:focus {
 display-widget.disabled button.flat.image-button:checked {
     background: alpha(@SLATE_700, 0.5);
 }
+
+.monitor-label {
+    border-radius: 9px;
+    font-weight: 600;
+}
+
+.monitor-label label {
+    margin: 1em;
+    text-shadow: 0 1px 1px alpha(white, 0.1);
+}

src/DisplayPlug.vala

@@ -81,30 +81,14 @@ public class Display.Plug : Switchboard.Plug {
             box = new Gtk.Box (VERTICAL, 0);
             box.append (headerbar);
             box.append (stack);
-
-            stack.notify["visible-child"].connect (() => {
-                if (stack.visible_child == displays_view) {
-                    displays_view.displays_overlay.show_windows ();
-                } else {
-                    displays_view.displays_overlay.hide_windows ();
-                }
-            });
         }
 
         return box;
     }
 
-    public override void shown () {
-        if (stack.visible_child == displays_view) {
-            displays_view.displays_overlay.show_windows ();
-        } else {
-            displays_view.displays_overlay.hide_windows ();
-        }
-    }
+    public override void shown () { } //Do nothing
 
-    public override void hidden () {
-        displays_view.displays_overlay.hide_windows ();
-    }
+    public override void hidden () { } //Do nothing
 
     public override void search_callback (string location) {
         stack.visible_child_name = location;

src/Widgets/DisplaysOverlay.vala

@@ -39,7 +39,6 @@ public class Display.DisplaysOverlay : Gtk.Box {
     private int default_y_margin = 0;
 
     private unowned Display.MonitorManager monitor_manager;
-    private static GalaDBus gala_dbus = null;
     public int active_displays { get; set; default = 0; }
 
     private List<DisplayWidget> display_widgets;
@@ -70,6 +69,7 @@ public class Display.DisplaysOverlay : Gtk.Box {
     };
 
     private Gtk.GestureDrag drag_gesture;
+    private MonitorLabel[] monitor_labels = {};
 
     construct {
         add_css_class (Granite.STYLE_CLASS_VIEW);
@@ -91,6 +91,9 @@ public class Display.DisplaysOverlay : Gtk.Box {
         rescan_displays ();
 
         overlay.get_child_position.connect (get_child_position);
+
+        map.connect (show_windows);
+        unmap.connect (hide_windows);
     }
 
     static construct {
@@ -102,20 +105,6 @@ public class Display.DisplaysOverlay : Gtk.Box {
             display_provider,
             Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION
         );
-
-        GLib.Bus.get_proxy.begin<GalaDBus> (
-            GLib.BusType.SESSION,
-            "org.pantheon.gala.daemon",
-            "/org/pantheon/gala/daemon",
-            GLib.DBusProxyFlags.NONE,
-            null,
-            (obj, res) => {
-            try {
-                gala_dbus = GLib.Bus.get_proxy.end (res);
-            } catch (GLib.Error e) {
-                critical (e.message);
-            }
-        });
     }
 
     private double prev_dx = 0;
@@ -202,38 +191,24 @@ public class Display.DisplaysOverlay : Gtk.Box {
         scanning = false;
     }
 
-    public void show_windows () requires (gala_dbus != null) {
+    public void show_windows () {
+        hide_windows ();
+        monitor_labels = {};
+
         if (monitor_manager.is_mirrored) {
             return;
         }
 
-        MonitorLabelInfo[] label_infos = {};
-
         foreach (unowned var widget in display_widgets) {
             if (widget.virtual_monitor.is_active) {
-                label_infos += MonitorLabelInfo () {
-                    monitor = label_infos.length,
-                    label = widget.virtual_monitor.get_display_name (),
-                    background_color = widget.bg_color,
-                    text_color = widget.text_color,
-                    x = widget.virtual_monitor.current_x,
-                    y = widget.virtual_monitor.current_y
-                };
+                monitor_labels += new MonitorLabel (monitor_labels.length, widget.virtual_monitor.get_display_name (), widget.bg_color, widget.text_color);
             }
         }
-
-        try {
-            gala_dbus.show_monitor_labels (label_infos);
-        } catch (Error e) {
-            warning ("Couldn't show monitor labels: %s", e.message);
-        }
     }
 
-    public void hide_windows () requires (gala_dbus != null) {
-        try {
-            gala_dbus.hide_monitor_labels ();
-        } catch (Error e) {
-            warning ("Couldn't hide monitor labels: %s", e.message);
+    public void hide_windows () {
+        foreach (var monitor_label in monitor_labels) {
+            monitor_label.close ();
         }
     }
 

src/Widgets/MonitorLabel.vala

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2024 elementary, Inc. (https://elementary.io)
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ */
+
+public class Display.MonitorLabel : Gtk.Window, PantheonWayland.ExtendedBehavior {
+    private const int SPACING = 12;
+    private const string COLORED_STYLE_CSS = """
+    .label-%d {
+        background-color: alpha(%s, 0.8);
+        color: %s;
+    }
+    """;
+
+    public int index { get; construct; }
+    public string label { get; construct; }
+    public string bg_color { get; construct; }
+    public string text_color { get; construct; }
+
+    public MonitorLabel (int index, string label, string bg_color, string text_color) {
+        Object (
+            index: index,
+            label: label,
+            bg_color: bg_color,
+            text_color: text_color
+        );
+    }
+
+    construct {
+        child = new Gtk.Label (label);
+
+        decorated = false;
+        resizable = false;
+        deletable = false;
+        can_focus = false;
+        titlebar = new Gtk.Grid ();
+
+        var provider = new Gtk.CssProvider ();
+        try {
+            provider.load_from_string (COLORED_STYLE_CSS.printf (index, bg_color, text_color));
+            get_style_context ().add_class ("label-%d".printf (index));
+            get_style_context ().add_class ("monitor-label");
+
+            Gtk.StyleContext.add_provider_for_display (
+                Gdk.Display.get_default (),
+                provider,
+                Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION
+            );
+        } catch (Error e) {
+            warning ("Failed to load CSS: %s", e.message);
+        }
+
+        child.realize.connect (() => {
+            var display = Gdk.Display.get_default ();
+            if (display is Gdk.X11.Display) {
+                unowned var xdisplay = ((Gdk.X11.Display) display).get_xdisplay ();
+
+                var window = ((Gdk.X11.Surface) get_surface ()).get_xid ();
+
+                var prop = xdisplay.intern_atom ("_MUTTER_HINTS", false);
+
+                var value = "monitor-label=%d".printf (index);
+
+                xdisplay.change_property (window, prop, X.XA_STRING, 8, 0, (uchar[]) value, value.length);
+            } else {
+                connect_to_shell ();
+                make_monitor_label (index);
+            }
+        });
+
+        present ();
+    }
+}

src/meson.build

@@ -2,7 +2,6 @@ plug_files = files(
     'Utils.vala',
     'SettingsDaemon.vala',
     'DisplayPlug.vala',
-    'Interfaces/GalaDBus.vala',
     'Interfaces/NightLightManager.vala',
     'Interfaces/MutterDisplayConfig.vala',
     'Interfaces/SensorManager.vala',
@@ -15,6 +14,7 @@ plug_files = files(
     'Views' / 'FiltersView.vala',
     'Widgets/DisplayWidget.vala',
     'Widgets/DisplaysOverlay.vala',
+    'Widgets' / 'MonitorLabel.vala',
 )
 
 switchboard_dep = dependency('switchboard-3')
@@ -31,7 +31,9 @@ shared_module(
         dependency('gobject-2.0'),
         dependency('granite-7'),
         dependency('gtk4'),
+        dependency('gtk4-x11'),
         dependency('libadwaita-1'),
+        dependency('pantheon-wayland-1'),
         meson.get_compiler('vala').find_library('posix'),
         switchboard_dep
     ],