wayland: Get/initialize a xdg_session_v1 object

Add the internal API to let the upper layers define a session
ID (e.g. saved from previous runs), and retrieve the session ID
eventually used (e.g. in case the session is created from scratch).

gdk/wayland/gdkdisplay-wayland.c

@@ -62,6 +62,7 @@
 #include "linux-dmabuf-unstable-v1-client-protocol.h"
 #include "presentation-time-client-protocol.h"
 #include "xx-color-management-v4-client-protocol.h"
+#include "xx-session-management-v1-client-protocol.h"
 
 #include "wm-button-layout-translation.h"
 
@@ -101,6 +102,7 @@
 #define NO_XDG_OUTPUT_DONE_SINCE_VERSION 3
 #define OUTPUT_VERSION           3
 #define XDG_WM_DIALOG_VERSION    1
+#define XX_SESSION_MANAGEMENT_VERSION 1
 
 #ifdef HAVE_TOPLEVEL_STATE_SUSPENDED
 #define XDG_WM_BASE_VERSION      6
@@ -311,6 +313,46 @@ static const struct org_kde_kwin_server_decoration_manager_listener server_decor
   .default_mode = server_decoration_manager_default_mode
 };
 
+static void
+session_listener_created (void                 *data,
+                          struct xx_session_v1 *xdg_session_v1,
+                          const char           *id)
+{
+  GdkWaylandDisplay *display_wayland = data;
+
+  GDK_DEBUG (MISC, "session created: %s", id);
+
+  if (g_strcmp0 (display_wayland->session_id, id) != 0)
+    {
+      g_clear_pointer (&display_wayland->session_id, g_free);
+      display_wayland->session_id = g_strdup (id);
+    }
+}
+
+static void
+session_listener_restored (void                 *data,
+                           struct xx_session_v1 *xdg_session_v1)
+{
+  GdkWaylandDisplay *display_wayland = data;
+
+  GDK_DEBUG (MISC, "session restored: %s", display_wayland->session_id);
+}
+
+static void
+session_listener_replaced (void                 *data,
+                           struct xx_session_v1 *xdg_session_v1)
+{
+  GdkWaylandDisplay *display_wayland = data;
+
+  GDK_DEBUG (MISC, "session replaced: %s", display_wayland->session_id);
+}
+
+static const struct xx_session_v1_listener xdg_session_listener = {
+  .created = session_listener_created,
+  .restored = session_listener_restored,
+  .replaced = session_listener_replaced,
+};
+
 /*
  * gdk_wayland_display_prefers_ssd:
  * @display: (type GdkWaylandDisplay): a `GdkDisplay`
@@ -393,6 +435,14 @@ gdk_registry_handle_global (void               *data,
                           &xdg_wm_dialog_v1_interface,
                           MIN (version, XDG_WM_DIALOG_VERSION));
     }
+  else if (strcmp (interface, xx_session_manager_v1_interface.name) == 0 &&
+           gdk_has_feature (GDK_FEATURE_SESSION_MANAGEMENT))
+    {
+      display_wayland->xdg_session_manager =
+        wl_registry_bind (display_wayland->wl_registry, id,
+                          &xx_session_manager_v1_interface,
+                          MIN (version, XX_SESSION_MANAGEMENT_VERSION));
+    }
   else if (strcmp (interface, gtk_shell1_interface.name) == 0)
     {
       display_wayland->gtk_shell =
@@ -767,6 +817,8 @@ gdk_wayland_display_dispose (GObject *object)
   g_clear_pointer (&display_wayland->linux_dmabuf, zwp_linux_dmabuf_v1_destroy);
   g_clear_pointer (&display_wayland->dmabuf_formats_info, dmabuf_formats_info_free);
   g_clear_pointer (&display_wayland->color, gdk_wayland_color_free);
+  g_clear_pointer (&display_wayland->xdg_session, xx_session_v1_destroy);
+  g_clear_pointer (&display_wayland->xdg_session_manager, xx_session_manager_v1_destroy);
 
   g_clear_pointer (&display_wayland->shm, wl_shm_destroy);
   g_clear_pointer (&display_wayland->wl_registry, wl_registry_destroy);
@@ -2809,3 +2861,51 @@ gdk_wayland_display_dispatch_queue (GdkDisplay            *display,
       _exit (1);
     }
 }
+
+void
+gdk_wayland_display_register_session (GdkDisplay *display,
+                                      const char *name)
+{
+  GdkWaylandDisplay *display_wayland = GDK_WAYLAND_DISPLAY (display);
+
+  GDK_DEBUG (MISC, "register session %s", name);
+
+  if (!display_wayland->xdg_session_manager)
+    return;
+
+  g_clear_pointer (&display_wayland->session_id, g_free);
+  display_wayland->session_id = g_strdup (name);
+
+  display_wayland->xdg_session =
+    xx_session_manager_v1_get_session (display_wayland->xdg_session_manager,
+                                       XX_SESSION_MANAGER_V1_REASON_LAUNCH,
+                                       name);
+  xx_session_v1_add_listener (display_wayland->xdg_session,
+                              &xdg_session_listener,
+                              display_wayland);
+
+  wl_display_roundtrip (display_wayland->wl_display);
+}
+
+void
+gdk_wayland_display_unregister_session (GdkDisplay *display)
+{
+  GdkWaylandDisplay *display_wayland = GDK_WAYLAND_DISPLAY (display);
+
+  if (!display_wayland->xdg_session_manager)
+    return;
+
+  if (display_wayland->xdg_session)
+    xx_session_v1_remove (display_wayland->xdg_session);
+
+  g_clear_pointer (&display_wayland->session_id, g_free);
+  g_clear_pointer (&display_wayland->xdg_session, xx_session_v1_destroy);
+}
+
+const char *
+gdk_wayland_display_get_current_session_id (GdkDisplay *display)
+{
+  GdkWaylandDisplay *display_wayland = GDK_WAYLAND_DISPLAY (display);
+
+  return display_wayland->session_id;
+}

gdk/wayland/gdkdisplay-wayland.h

@@ -42,6 +42,7 @@
 #include <gdk/wayland/presentation-time-client-protocol.h>
 #include <gdk/wayland/single-pixel-buffer-v1-client-protocol.h>
 #include <gdk/wayland/xdg-dialog-v1-client-protocol.h>
+#include <gdk/wayland/xdg-session-management-v1-client-protocol.h>
 
 #include <glib.h>
 #include <gdk/gdkkeys.h>
@@ -124,6 +125,8 @@ struct _GdkWaylandDisplay
   struct wp_viewporter *viewporter;
   struct wp_presentation *presentation;
   struct wp_single_pixel_buffer_manager_v1 *single_pixel_buffer;
+  struct xdg_session_manager_v1 *xdg_session_manager;
+  struct xdg_session_v1 *xdg_session;
   GdkWaylandColor *color;
 
   GList *async_roundtrips;
@@ -153,6 +156,8 @@ struct _GdkWaylandDisplay
 
   GListStore *monitors;
 
+  char *session_id;
+
   gint64 last_bell_time_ms;
 };
 

gdk/wayland/gdkwaylanddisplay.h

@@ -65,5 +65,12 @@ gboolean                gdk_wayland_display_query_registry      (GdkDisplay  *di
 GDK_AVAILABLE_IN_4_4
 gpointer                gdk_wayland_display_get_egl_display     (GdkDisplay  *display);
 
+void                    gdk_wayland_display_register_session    (GdkDisplay *display,
+                                                                 const char *name);
+
+void                    gdk_wayland_display_unregister_session  (GdkDisplay *display);
+
+const char *            gdk_wayland_display_get_current_session_id (GdkDisplay *display);
+
 G_END_DECLS