wayland: Make gtk_shell handle our private window states

Instead of using the "allocated" state ranges of xdg_shell, lets just
use our own gtk_shell by adding a state enum and a configure event.

https://bugzilla.gnome.org/show_bug.cgi?id=769936

src/wayland/meta-wayland-gtk-shell.c

@@ -40,6 +40,7 @@ typedef struct _MetaWaylandGtkSurface
   struct wl_resource *resource;
   MetaWaylandSurface *surface;
   gboolean is_modal;
+  gulong configure_handler_id;
 } MetaWaylandGtkSurface;
 
 static void
@@ -48,8 +49,12 @@ gtk_surface_destructor (struct wl_resource *resource)
   MetaWaylandGtkSurface *gtk_surface = wl_resource_get_user_data (resource);
 
   if (gtk_surface->surface)
+    {
       g_object_steal_qdata (G_OBJECT (gtk_surface->surface),
                             quark_gtk_surface_data);
+      g_signal_handler_disconnect (gtk_surface->surface,
+                                   gtk_surface->configure_handler_id);
+    }
 
   g_free (gtk_surface);
 }
@@ -142,6 +147,34 @@ gtk_surface_surface_destroyed (MetaWaylandGtkSurface *gtk_surface)
   gtk_surface->surface = NULL;
 }
 
+static void
+fill_states (struct wl_array *states,
+             MetaWindow      *window)
+{
+  uint32_t *s;
+
+  if (window->tile_mode == META_TILE_LEFT ||
+      window->tile_mode == META_TILE_RIGHT)
+    {
+      s = wl_array_add (states, sizeof *s);
+      *s = GTK_SURFACE1_STATE_TILED;
+    }
+}
+
+static void
+on_configure (MetaWaylandSurface    *surface,
+              MetaWaylandGtkSurface *gtk_surface)
+{
+  struct wl_array states;
+
+  wl_array_init (&states);
+  fill_states (&states, surface->window);
+
+  gtk_surface1_send_configure (gtk_surface->resource, &states);
+
+  wl_array_release (&states);
+}
+
 static void
 gtk_shell_get_gtk_surface (struct wl_client   *client,
                            struct wl_resource *resource,
@@ -170,6 +203,11 @@ gtk_shell_get_gtk_surface (struct wl_client   *client,
                                   &meta_wayland_gtk_surface_interface,
                                   gtk_surface, gtk_surface_destructor);
 
+  gtk_surface->configure_handler_id = g_signal_connect (surface,
+                                                        "configure",
+                                                        G_CALLBACK (on_configure),
+                                                        gtk_surface);
+
   g_object_set_qdata_full (G_OBJECT (surface),
                            quark_gtk_surface_data,
                            gtk_surface,

src/wayland/meta-wayland-xdg-shell.c

@@ -35,13 +35,6 @@
 #include "wayland/meta-window-wayland.h"
 #include "xdg-shell-unstable-v5-server-protocol.h"
 
-/*
- * Define GNOME additional states to xdg-shell
- * The current reserved range for GNOME is 0x1000 - 0x1FFF
- */
-
-#define XDG_SURFACE_STATE_GNOME_TILED 0x1000
-
 struct _MetaWaylandXdgSurface
 {
   MetaWaylandSurfaceRoleShellSurface parent;
@@ -406,13 +399,6 @@ fill_states (struct wl_array *states, MetaWindow *window)
       s = wl_array_add (states, sizeof *s);
       *s = XDG_SURFACE_STATE_ACTIVATED;
     }
-  /* GNOME extension to xdg-shell states */
-  if (window->tile_mode == META_TILE_LEFT ||
-      window->tile_mode == META_TILE_RIGHT)
-    {
-      s = wl_array_add (states, sizeof *s);
-      *s = XDG_SURFACE_STATE_GNOME_TILED;
-    }
 }
 
 static void

src/wayland/protocol/gtk-shell.xml

@@ -46,6 +46,16 @@
     <request name="present">
       <arg name="time" type="uint"/>
     </request>
+
+    <!-- Version 2 additions -->
+
+    <enum name="state">
+      <entry name="tiled" value="1"/>
+    </enum>
+
+    <event name="configure">
+      <arg name="states" type="array"/>
+    </event>
   </interface>
 
 </protocol>