Add style transition API

.gitignore

@@ -1,11 +1,11 @@
+*~
 ABOUT-NLS
 aclocal.m4
 autom4te.cache
 /build-aux/*
 ChangeLog
 config.h
 config.h.in
-config.h.in~
 config.log
 config.status
 configure

daemon/Main.vala

@@ -1,21 +1,30 @@
-//
-//  Copyright (c) 2018 elementary LLC. (https://elementary.io)
-//
-//  This program is free software: you can redistribute it and/or modify
-//  it under the terms of the GNU General Public License as published by
-//  the Free Software Foundation, either version 3 of the License, or
-//  (at your option) any later version.
-//
-//  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/>.
-//
+/*
+ * Copyright 2018–2021 elementary, Inc. (https://elementary.io)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/>.
+ */
 
 namespace Gala {
+    const string DBUS_NAME = "org.pantheon.gala";
+    const string DBUS_OBJECT_PATH = "/org/pantheon/gala";
+
+    [DBus (name = "org.pantheon.gala")]
+    public interface WMDBus : GLib.Object {
+        public abstract void perform_action (Gala.ActionType type) throws DBusError, IOError;
+        public abstract void global_transition_from_snapshot () throws DBusError, IOError;
+    }
+
     [DBus (name = "org.gnome.SessionManager")]
     public interface SessionManager : Object {
         public abstract async ObjectPath register_client (
@@ -35,6 +44,7 @@ namespace Gala {
     }
 
     public class Daemon {
+        public WMDBus? wm_proxy { get; private set; }
         SessionClient? sclient = null;
 
         public Daemon () {
@@ -45,16 +55,26 @@ namespace Gala {
                 }
             });
 
+            Bus.watch_name (BusType.SESSION, DBUS_NAME, BusNameWatcherFlags.NONE, gala_appeared, lost_gala);
+
             var granite_settings = Granite.Settings.get_default ();
             var gtk_settings = Gtk.Settings.get_default ();
 
             gtk_settings.gtk_application_prefer_dark_theme = granite_settings.prefers_color_scheme == Granite.Settings.ColorScheme.DARK;
 
             granite_settings.notify["prefers-color-scheme"].connect (() => {
+                if (wm_proxy != null) {
+                    try {
+                        wm_proxy.global_transition_from_snapshot ();
+                    } catch (Error e) {
+                        warning ("Failed to create a global transition: %s", e.message);
+                    }
+                }
+
                 gtk_settings.gtk_application_prefer_dark_theme = granite_settings.prefers_color_scheme == Granite.Settings.ColorScheme.DARK;
             });
 
-            var menu_daemon = new MenuDaemon ();
+            var menu_daemon = new MenuDaemon (this);
             menu_daemon.setup_dbus ();
         }
 
@@ -131,6 +151,24 @@ namespace Gala {
                 warning ("Unable to respond to session manager: %s", e.message);
             }
         }
+
+        void on_gala_get (GLib.Object? o, GLib.AsyncResult? res) {
+            try {
+                wm_proxy = Bus.get_proxy.end (res);
+            } catch (Error e) {
+                warning ("Failed to get Gala proxy: %s", e.message);
+            }
+        }
+
+        void lost_gala () {
+            wm_proxy = null;
+        }
+
+        void gala_appeared () {
+            if (wm_proxy == null) {
+                Bus.get_proxy.begin<WMDBus> (BusType.SESSION, DBUS_NAME, DBUS_OBJECT_PATH, 0, null, on_gala_get);
+            }
+        }
     }
 
     public static int main (string[] args) {

daemon/MenuDaemon.vala

@@ -1,32 +1,24 @@
-//
-//  Copyright 2018-2020 elementary, Inc. (https://elementary.io)
-//
-//  This program is free software: you can redistribute it and/or modify
-//  it under the terms of the GNU General Public License as published by
-//  the Free Software Foundation, either version 3 of the License, or
-//  (at your option) any later version.
-//
-//  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/>.
-//
+/*
+ * Copyright 2018–2021 elementary, Inc. (https://elementary.io)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/>.
+ */
 
 namespace Gala {
-    const string DBUS_NAME = "org.pantheon.gala";
-    const string DBUS_OBJECT_PATH = "/org/pantheon/gala";
-
     const string DAEMON_DBUS_NAME = "org.pantheon.gala.daemon";
     const string DAEMON_DBUS_OBJECT_PATH = "/org/pantheon/gala/daemon";
 
-    [DBus (name = "org.pantheon.gala")]
-    public interface WMDBus : GLib.Object {
-        public abstract void perform_action (Gala.ActionType type) throws DBusError, IOError;
-    }
-
     [DBus (name = "org.pantheon.gala.daemon")]
     public class MenuDaemon : Object {
         // Window Menu
@@ -39,6 +31,7 @@ namespace Gala {
         private Granite.AccelLabel on_visible_workspace_accellabel;
         private Granite.AccelLabel resize_accellabel;
         private Granite.AccelLabel screenshot_accellabel;
+        unowned Daemon daemon;
         Gtk.Menu? window_menu = null;
         Gtk.MenuItem hide;
         Gtk.MenuItem maximize;
@@ -54,8 +47,6 @@ namespace Gala {
         // Desktop Menu
         Gtk.Menu? desktop_menu = null;
 
-        WMDBus? wm_proxy = null;
-
         ulong always_on_top_sid = 0U;
         ulong on_visible_workspace_sid = 0U;
 
@@ -71,26 +62,10 @@ namespace Gala {
         public void setup_dbus () {
             var flags = BusNameOwnerFlags.ALLOW_REPLACEMENT | BusNameOwnerFlags.REPLACE;
             Bus.own_name (BusType.SESSION, DAEMON_DBUS_NAME, flags, on_bus_acquired, () => {}, null);
-
-            Bus.watch_name (BusType.SESSION, DBUS_NAME, BusNameWatcherFlags.NONE, gala_appeared, lost_gala);
         }
 
-        void on_gala_get (GLib.Object? o, GLib.AsyncResult? res) {
-            try {
-                wm_proxy = Bus.get_proxy.end (res);
-            } catch (Error e) {
-                warning ("Failed to get Gala proxy: %s", e.message);
-            }
-        }
-
-        void lost_gala () {
-            wm_proxy = null;
-        }
-
-        void gala_appeared () {
-            if (wm_proxy == null) {
-                Bus.get_proxy.begin<WMDBus> (BusType.SESSION, DBUS_NAME, DBUS_OBJECT_PATH, 0, null, on_gala_get);
-            }
+        public MenuDaemon (Daemon daemon) {
+            this.daemon = daemon;
         }
 
         void on_bus_acquired (DBusConnection conn) {
@@ -102,9 +77,9 @@ namespace Gala {
         }
 
         void perform_action (Gala.ActionType type) {
-            if (wm_proxy != null) {
+            if (daemon.wm_proxy != null) {
                 try {
-                    wm_proxy.perform_action (type);
+                    daemon.wm_proxy.perform_action (type);
                 } catch (Error e) {
                     warning ("Failed to perform Gala action over DBus: %s", e.message);
                 }

lib/Constants.vala

@@ -1,19 +1,19 @@
-//
-//  Copyright 2019 elementary, Inc. (https://elementary.io)
-//
-//  This program is free software: you can redistribute it and/or modify
-//  it under the terms of the GNU General Public License as published by
-//  the Free Software Foundation, either version 3 of the License, or
-//  (at your option) any later version.
-//
-//  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/>.
-//
+/*
+ * Copyright 2019–2021 elementary, Inc. (https://elementary.io)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/>.
+ */
 
 namespace Gala {
     [CCode (has_type_id = false)]
@@ -33,5 +33,7 @@ namespace Gala {
         WORKSPACE_SWITCH = 400,
         // Duration of the nudge animation when trying to switch to at the end of the workspace list
         NUDGE = 360,
+        // Dark/light style switch animation
+        STYLE_SWITCH = 200
     }
 }