Support X11

src/Application.vala

@@ -4,8 +4,17 @@
  */
 
 public class Dock.Application : Gtk.Application {
+    const OptionEntry[] ENTRIES = {
+        { "id", '\0', OptionFlags.NONE, OptionArg.STRING, out id, "Launch dock with the specific window id", null },
+        { null }
+    };
+
+    public static string? id;
+
     public Application () {
         Object (application_id: "io.elementary.dock");
+
+        add_main_option_entries (ENTRIES);
     }
 
     protected override void startup () {
@@ -26,7 +35,9 @@ public class Dock.Application : Gtk.Application {
 
     protected override void activate () {
         if (active_window == null) {
-            var main_window = new MainWindow ();
+            var main_window = new MainWindow () {
+                title = (id != null) ? id : application_id
+            };
 
             add_window (main_window);
 

src/DBus/PantheonShellX11.vala

@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ * SPDX-FileCopyrightText: 2024 elementary, Inc. (https://elementary.io)
+ */
+
+[DBus (name = "io.elementary.gala.PantheonShellX11")]
+public interface Dock.PantheonShellX11 : GLib.Object {
+    public abstract void set_anchor (string id, Pantheon.Desktop.Anchor anchor) throws GLib.Error;
+    public abstract void set_size (string id, int width, int height) throws GLib.Error;
+    public abstract void set_hide_mode (string id, Pantheon.Desktop.HideMode hide_mode) throws GLib.Error;
+    public abstract void make_centered (string id) throws GLib.Error;
+}

src/MainWindow.vala

@@ -9,6 +9,8 @@ public class Dock.MainWindow : Gtk.ApplicationWindow {
     private Pantheon.Desktop.Shell? desktop_shell;
     private Pantheon.Desktop.Panel? panel;
 
+    PantheonShellX11? pantheon_shell_x11_dbus;
+
     class construct {
         set_css_name ("dock");
     }
@@ -25,11 +27,27 @@ public class Dock.MainWindow : Gtk.ApplicationWindow {
         var drop_target_launcher = new Gtk.DropTarget (typeof (Launcher), MOVE);
         launcher_manager.add_controller (drop_target_launcher);
 
-        launcher_manager.realize.connect (init_panel);
+        show.connect (() => {
+            if (is_wayland ()) {
+                init_panel ();
+            } else {
+                init_x11_panel ();
+            }
+        });
 
         settings.changed.connect ((key) => {
-            if (key == "autohide-mode" && panel != null) {
+            if (key != "autohide-mode") {
+                return;
+            }
+
+            if (is_wayland () && panel != null) {
                 panel.set_hide_mode (settings.get_enum ("autohide-mode"));
+            } else if (!is_wayland () && pantheon_shell_x11_dbus != null && title != null) {
+                try {
+                    pantheon_shell_x11_dbus.set_hide_mode (title, settings.get_enum ("autohide-mode"));
+                } catch (GLib.Error e) {
+                    warning ("Unable to update the hide mode: %s", e.message);
+                }
             }
         });
     }
@@ -64,4 +82,18 @@ public class Dock.MainWindow : Gtk.ApplicationWindow {
             }
         }
     }
+
+    private bool is_wayland () {
+        return Gdk.Display.get_default () is Gdk.Wayland.Display;
+    }
+
+    private void init_x11_panel () requires (title != null) {
+        try {
+            pantheon_shell_x11_dbus = Bus.get_proxy_sync (BusType.SESSION, "io.elementary.gala.PantheonShellX11", "/io/elementary/gala/PantheonShellX11");
+            pantheon_shell_x11_dbus.set_anchor (title, BOTTOM);
+            pantheon_shell_x11_dbus.set_hide_mode (title, settings.get_enum ("autohide-mode"));
+        } catch (GLib.Error e) {
+            critical ("Unable to setup PantheonShellX11: %s", e.message);
+        }
+    }
 }

src/meson.build

@@ -8,6 +8,7 @@ sources = [
     'MainWindow.vala',
     'PoofPopover.vala',
     'DBus' / 'ItemInterface.vala',
+    'DBus' / 'PantheonShellX11.vala',
     'DBus' / 'ShellKeyGrabber.vala',
     'DBus' / 'SwitcherooControl.vala',
     'DBus' / 'Unity.vala'