[Wayland] Bump gtk-shell-v1 protocol to version 6 (#736)

* [Wayland] gtk-shell: Fix MetaWaylandGtkSurface leak on surface destroy

The MetaWaylandSurface corresponding to a MetaWaylandGtkSurface can be
destroyed before the MetaWaylandGtkSurface is destroyed. In its destroy
function MetaWaylandSurface however was unsetting the destructor of the
correspnding resource along with the gtk_surface1 interface
implementation. This was done to prevent further gtk_surface1 requests
on a NULLed MetaWaylandSurface, if it has been destroyed before the
MetaWaylandGtkSurface.

It would be enough to just unset the resource implementation, while
keeping the destructor to fix this leak. However the following commit
will rely on the implementation being available after the
MetaWaylandSurface has been destroyed. So instead introduce NULL checks
for all functions that can be called on the gtk_surface1 interface and
do not unset the implementation.

Original Mutter commit: https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1307/diffs?commit_id=b41c4aec2677a48e30a54f731b3d7ef9924b48ea

* [Wayland] gtk-shell: Add an explicit gtk-shell surface release request

Previously the wl_resource and MetaWaylandGtkSurface corresponding to
any client gtk_surface have been kept around until the exit of the
client due to the client side destroy method not signaling the
destruction to the server. Ideally the protocol would have specified a
destroy request marked as destructor to handle this automatically,
however this is no longer possible due to the destroy method being
implicitly generated in the absence of an explicit request in the
protocol. Adding a destroy request marked as destructor now would
generate a new destroy method that unconditionally would send the
request to the server, which would break clients running on servers not
supporting that request.

So instead of modifying the destroy request add a new "release"
destructor, that indicates to the server that it can release the
resource. This can be optionally be used by clients depending on the
server protocol version.

Original Mutter commit: https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1307/diffs?commit_id=c9aa43aa7a40bb0a74c9d98836599825441fc154

* [Wayland] Bump gtk-shell-v1 protocol to version 5

Added titlebar_gesture request. This allows client to delegate titlebar gestures to the compositor,
which allows for better consistency with server-side decorations,
and a wider range of actions (including lower-on-middle-click).

Original Mutter MR: https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1944

* [Wayland] Bump gtk-shell-v1 protocol to version 6

No actual changes. We will use this version to hint GTK about
the availability of non broken wl_surface.offset support for
pointer cursors.

* Replace all G_DESKTOP with C_DESKTOP

* debian: update libmuffin0.symbols

Author: Sunderland93

debian/libmuffin0.symbols

@@ -879,6 +879,7 @@ libmuffin-clutter-0.so.0 libmuffin0 #MINVER#
  clutter_modifier_type_get_type@Base 5.3.0
  clutter_offscreen_effect_create_texture@Base 5.3.0
  clutter_offscreen_effect_get_pipeline@Base 6.6.0
+ clutter_offscreen_effect_get_pipeline@Base 6.4.1
  clutter_offscreen_effect_get_target@Base 5.3.0
  clutter_offscreen_effect_get_target_rect@Base 5.3.0
  clutter_offscreen_effect_get_target_size@Base 5.3.0
@@ -2670,6 +2671,7 @@ libmuffin.so.0 libmuffin0 #MINVER#
  meta_window_kill@Base 5.3.0
  meta_window_located_on_workspace@Base 5.3.0
  meta_window_lower@Base 5.3.0
+ meta_window_lower_with_transients@Base 6.4.1
  meta_window_make_above@Base 5.3.0
  meta_window_make_fullscreen@Base 5.3.0
  meta_window_maximize@Base 5.3.0

src/core/window.c

@@ -5624,6 +5624,62 @@ meta_window_lower (MetaWindow  *window)
   meta_stack_lower (window->display->stack, window);
 }
 
+static gboolean
+lower_window_and_transients (MetaWindow *window,
+                             gpointer    user_data)
+{
+  MetaWorkspaceManager *workspace_manager = window->display->workspace_manager;
+
+  meta_window_lower (window);
+
+  meta_window_foreach_transient (window, lower_window_and_transients, NULL);
+
+  if (meta_prefs_get_raise_on_click ())
+  {
+    /* Move window to the back of the focusing workspace's MRU list.
+     * Do extra sanity checks to avoid possible race conditions.
+     * (Borrowed from window.c.)
+     */
+    if (workspace_manager->active_workspace &&
+      meta_window_located_on_workspace (window,
+                                        workspace_manager->active_workspace))
+    {
+      GList *link;
+      link = g_list_find (workspace_manager->active_workspace->mru_list,
+                          window);
+      g_assert (link);
+
+      workspace_manager->active_workspace->mru_list =
+      g_list_remove_link (workspace_manager->active_workspace->mru_list,
+                          link);
+      g_list_free (link);
+
+      workspace_manager->active_workspace->mru_list =
+      g_list_append (workspace_manager->active_workspace->mru_list,
+                     window);
+    }
+  }
+
+  return FALSE;
+}
+
+void
+meta_window_lower_with_transients (MetaWindow *window,
+                                   uint32_t    timestamp)
+{
+  MetaWorkspaceManager *workspace_manager = window->display->workspace_manager;
+
+  lower_window_and_transients (window, NULL);
+
+  /* Rather than try to figure that out whether we just lowered
+   * the focus window, assume that's always the case. (Typically,
+   * this will be invoked via keyboard action or by a mouse action;
+   * in either case the window or a modal child will have been focused.) */
+  meta_workspace_focus_default_window (workspace_manager->active_workspace,
+                                       NULL,
+                                       timestamp);
+}
+
 /*
  * Move window to the requested workspace; append controls whether new WS
  * should be created if one does not exist.

src/meta/window.h

@@ -317,6 +317,10 @@ void        meta_window_raise              (MetaWindow  *window);
 META_EXPORT
 void        meta_window_lower              (MetaWindow  *window);
 
+META_EXPORT
+void        meta_window_lower_with_transients (MetaWindow *window,
+                                               uint32_t    timestamp);
+
 META_EXPORT
 const char *meta_window_get_title (MetaWindow *window);
 

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

@@ -83,6 +83,9 @@ gtk_surface_set_dbus_properties (struct wl_client   *client,
   MetaWaylandSurface *surface = gtk_surface->surface;
   MetaWindow *window;
 
+  if (!surface)
+    return;
+
   window = meta_wayland_surface_get_window (surface);
   if (!window)
     return;
@@ -104,6 +107,9 @@ gtk_surface_set_modal (struct wl_client   *client,
   MetaWaylandSurface *surface = gtk_surface->surface;
   MetaWindow *window;
 
+  if (!surface)
+    return;
+
   window = meta_wayland_surface_get_window (surface);
   if (!window)
     return;
@@ -123,6 +129,9 @@ gtk_surface_unset_modal (struct wl_client   *client,
   MetaWaylandSurface *surface = gtk_surface->surface;
   MetaWindow *window;
 
+  if (!surface)
+    return;
+
   window = meta_wayland_surface_get_window (surface);
   if (!window)
     return;
@@ -143,6 +152,9 @@ gtk_surface_present (struct wl_client   *client,
   MetaWaylandSurface *surface = gtk_surface->surface;
   MetaWindow *window;
 
+  if (!surface)
+    return;
+
   window = meta_wayland_surface_get_window (surface);
   if (!window)
     return;
@@ -162,6 +174,9 @@ gtk_surface_request_focus (struct wl_client   *client,
   MetaStartupSequence *sequence = NULL;
   MetaWindow *window;
 
+  if (!surface)
+    return;
+
   window = meta_wayland_surface_get_window (surface);
   if (!window)
     return;
@@ -193,19 +208,119 @@ gtk_surface_request_focus (struct wl_client   *client,
     }
 }
 
+static void
+gtk_surface_titlebar_gesture (struct wl_client   *client,
+                              struct wl_resource *resource,
+                              uint32_t            serial,
+                              struct wl_resource *seat_resource,
+                              uint32_t            gesture)
+{
+  MetaWaylandGtkSurface *gtk_surface = wl_resource_get_user_data (resource);
+  MetaWaylandSurface *surface = gtk_surface->surface;
+  MetaWaylandSeat *seat = wl_resource_get_user_data (seat_resource);
+  CDesktopTitlebarAction action = C_DESKTOP_TITLEBAR_ACTION_NONE;
+  MetaWindow *window;
+  float x, y;
+
+  if (!surface)
+    return;
+
+  window = meta_wayland_surface_get_window (surface);
+  if (!window)
+    return;
+
+
+
+  if (!meta_wayland_seat_get_grab_info (seat, surface, serial, FALSE, &x, &y))
+    return;
+
+  switch (gesture)
+  {
+    case GTK_SURFACE1_GESTURE_DOUBLE_CLICK:
+      action = meta_prefs_get_action_double_click_titlebar ();
+      break;
+    case GTK_SURFACE1_GESTURE_RIGHT_CLICK:
+      action = meta_prefs_get_action_right_click_titlebar ();
+      break;
+    case GTK_SURFACE1_GESTURE_MIDDLE_CLICK:
+      action = meta_prefs_get_action_middle_click_titlebar ();
+      break;
+    default:
+      wl_resource_post_error (resource,
+                              GTK_SURFACE1_ERROR_INVALID_GESTURE,
+                              "Invalid gesture passed");
+      break;
+
+  }
+
+  switch (action)
+  {
+    case C_DESKTOP_TITLEBAR_ACTION_TOGGLE_MAXIMIZE:
+      if (META_WINDOW_MAXIMIZED (window))
+        meta_window_unmaximize (window, META_MAXIMIZE_BOTH);
+    else
+      meta_window_maximize (window, META_MAXIMIZE_BOTH);
+    break;
+
+    case C_DESKTOP_TITLEBAR_ACTION_TOGGLE_MAXIMIZE_HORIZONTALLY:
+      if (META_WINDOW_MAXIMIZED_HORIZONTALLY (window))
+        meta_window_unmaximize (window, META_MAXIMIZE_HORIZONTAL);
+    else
+      meta_window_maximize (window, META_MAXIMIZE_HORIZONTAL);
+    break;
+
+    case C_DESKTOP_TITLEBAR_ACTION_TOGGLE_MAXIMIZE_VERTICALLY:
+      if (META_WINDOW_MAXIMIZED_VERTICALLY (window))
+        meta_window_unmaximize (window, META_MAXIMIZE_VERTICAL);
+    else
+      meta_window_maximize (window, META_MAXIMIZE_VERTICAL);
+    break;
+
+    case C_DESKTOP_TITLEBAR_ACTION_MINIMIZE:
+      meta_window_minimize (window);
+      break;
+
+    case C_DESKTOP_TITLEBAR_ACTION_LOWER:
+    {
+      uint32_t timestamp;
+
+      timestamp = meta_display_get_current_time_roundtrip (window->display);
+      meta_window_lower_with_transients (window, timestamp);
+    }
+    break;
+
+    case C_DESKTOP_TITLEBAR_ACTION_MENU:
+      meta_window_show_menu (window, META_WINDOW_MENU_WM, x, y);
+      break;
+
+    case C_DESKTOP_TITLEBAR_ACTION_TOGGLE_SHADE:
+      g_warning ("No shade! The library is closed.");
+      G_GNUC_FALLTHROUGH;
+    default:
+      return;
+  }
+}
+
+static void
+gtk_surface_release (struct wl_client   *client,
+                     struct wl_resource *resource)
+{
+  wl_resource_destroy (resource);
+}
+
 static const struct gtk_surface1_interface meta_wayland_gtk_surface_interface = {
   gtk_surface_set_dbus_properties,
   gtk_surface_set_modal,
   gtk_surface_unset_modal,
   gtk_surface_present,
   gtk_surface_request_focus,
+  gtk_surface_release,
+  gtk_surface_titlebar_gesture
 };
 
 static void
 gtk_surface_surface_destroyed (MetaWaylandGtkSurface *gtk_surface)
 {
-  wl_resource_set_implementation (gtk_surface->resource,
-                                  NULL, NULL, NULL);
   gtk_surface->surface = NULL;
 }
 

src/wayland/meta-wayland-versions.h

@@ -41,7 +41,7 @@
 #define META_WL_SEAT_VERSION                5
 #define META_WL_OUTPUT_VERSION              4
 #define META_XSERVER_VERSION                1
-#define META_GTK_SHELL1_VERSION             3
+#define META_GTK_SHELL1_VERSION             6
 #define META_WL_SUBCOMPOSITOR_VERSION       1
 #define META_ZWP_POINTER_GESTURES_V1_VERSION 3
 #define META_ZXDG_EXPORTER_V1_VERSION       1

src/wayland/protocol/gtk-shell.xml

@@ -1,6 +1,6 @@
 <protocol name="gtk">
 
-  <interface name="gtk_shell1" version="3">
+  <interface name="gtk_shell1" version="6">
     <description summary="gtk specific extensions">
       gtk_shell is a protocol extension providing additional features for
       clients implementing it.
@@ -33,9 +33,11 @@
     <request name="notify_launch" since="3">
       <arg name="startup_id" type="string"/>
     </request>
+
+    <!-- Version 6 does not add new API, but asserts that surface offsets are implemented -->
   </interface>
 
-  <interface name="gtk_surface1" version="3">
+  <interface name="gtk_surface1" version="6">
     <request name="set_dbus_properties">
       <arg name="application_id" type="string" allow-null="true"/>
       <arg name="app_menu_path" type="string" allow-null="true"/>
@@ -82,6 +84,28 @@
     <request name="request_focus" since="3">
       <arg name="startup_id" type="string" allow-null="true"/>
     </request>
+
+    <!-- Version 4 additions -->
+    <request name="release" type="destructor" since="4"/>
+
+    <!-- Version 5 additions -->
+    <enum name="gesture" since="5">
+      <entry name="double_click" value="1"/>
+      <entry name="right_click" value="2"/>
+      <entry name="middle_click" value="3"/>
+    </enum>
+
+    <enum name="error" since="5">
+      <entry name="invalid_gesture" value="0"/>
+    </enum>
+
+    <request name="titlebar_gesture" since="5">
+      <arg name="serial" type="uint"/>
+      <arg name="seat" type="object" interface="wl_seat"/>
+      <arg name="gesture" type="uint" enum="gesture"/>
+    </request>
+
+    <!-- Version 6 does not add new API, but asserts that surface offsets are implemented -->
   </interface>
 
 </protocol>

src/x11/meta-x11-window-control.c

@@ -61,62 +61,14 @@ meta_x11_wm_queue_frame_resize (MetaX11Display *x11_display,
   meta_window_frame_size_changed (window);
 }
 
-static gboolean
-lower_window_and_transients (MetaWindow *window,
-                             gpointer   data)
-{
-  MetaWorkspaceManager *workspace_manager = window->display->workspace_manager;
-
-  meta_window_lower (window);
-
-  meta_window_foreach_transient (window, lower_window_and_transients, NULL);
-
-  if (meta_prefs_get_raise_on_click ())
-    {
-      /* Move window to the back of the focusing workspace's MRU list.
-       * Do extra sanity checks to avoid possible race conditions.
-       * (Borrowed from window.c.)
-       */
-      if (workspace_manager->active_workspace &&
-          meta_window_located_on_workspace (window,
-                                            workspace_manager->active_workspace))
-        {
-          GList* link;
-          link = g_list_find (workspace_manager->active_workspace->mru_list,
-                              window);
-          g_assert (link);
-
-          workspace_manager->active_workspace->mru_list =
-            g_list_remove_link (workspace_manager->active_workspace->mru_list,
-                                link);
-          g_list_free (link);
-
-          workspace_manager->active_workspace->mru_list =
-            g_list_append (workspace_manager->active_workspace->mru_list,
-                           window);
-        }
-    }
-
-  return FALSE;
-}
-
 void
 meta_x11_wm_user_lower_and_unfocus (MetaX11Display *x11_display,
                                     Window          frame_xwindow,
                                     uint32_t        timestamp)
 {
   MetaWindow *window = window_from_frame (x11_display, frame_xwindow);
-  MetaWorkspaceManager *workspace_manager = window->display->workspace_manager;
-
-  lower_window_and_transients (window, NULL);
 
- /* Rather than try to figure that out whether we just lowered
-  * the focus window, assume that's always the case. (Typically,
-  * this will be invoked via keyboard action or by a mouse action;
-  * in either case the window or a modal child will have been focused.) */
-  meta_workspace_focus_default_window (workspace_manager->active_workspace,
-                                       NULL,
-                                       timestamp);
+  meta_window_lower_with_transients (window, timestamp);
 }
 
 void