[mutter] wayland: Introduce MetaWaylandSurfaceRole

[Jonas Ådahl <jadahl src gnome org>]

commit 945bf626c697dafb59703f46c5ebc821235dbd01
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Feb 6 16:12:21 2015 +0800

    wayland: Introduce MetaWaylandSurfaceRole
    
    Introduce surface roles and use it to ensure a surface never changes
    role.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=744452

 src/wayland/meta-wayland-data-device.c |    6 ++++
 src/wayland/meta-wayland-pointer.c     |    9 ++++++
 src/wayland/meta-wayland-surface.c     |   45 ++++++++++++++++++++++++++++++++
 src/wayland/meta-wayland-surface.h     |   17 ++++++++++++
 4 files changed, 77 insertions(+), 0 deletions(-)
---
diff --git a/src/wayland/meta-wayland-data-device.c b/src/wayland/meta-wayland-data-device.c
index 36675a5..13ea84f 100644
--- a/src/wayland/meta-wayland-data-device.c
+++ b/src/wayland/meta-wayland-data-device.c
@@ -410,6 +410,12 @@ data_device_start_drag (struct wl_client *client,
       seat->pointer.grab != &seat->pointer.default_grab)
     return;
 
+  if (meta_wayland_surface_set_role (surface,
+                                     META_WAYLAND_SURFACE_ROLE_DND,
+                                     resource,
+                                     WL_DATA_DEVICE_ERROR_ROLE) != 0)
+    return;
+
   data_device->current_grab = drag_grab = g_slice_new0 (MetaWaylandDragGrab);
 
   drag_grab->generic.interface = &drag_grab_interface;
diff --git a/src/wayland/meta-wayland-pointer.c b/src/wayland/meta-wayland-pointer.c
index b74842a..d2227ab 100644
--- a/src/wayland/meta-wayland-pointer.c
+++ b/src/wayland/meta-wayland-pointer.c
@@ -786,6 +786,15 @@ pointer_set_cursor (struct wl_client *client,
   if (pointer->focus_serial - serial > G_MAXUINT32 / 2)
     return;
 
+  if (surface)
+    {
+      if (meta_wayland_surface_set_role (surface,
+                                         META_WAYLAND_SURFACE_ROLE_CURSOR,
+                                         resource,
+                                         WL_POINTER_ERROR_ROLE) != 0)
+        return;
+    }
+
   pointer->hotspot_x = x;
   pointer->hotspot_y = y;
   set_cursor_surface (pointer, surface);
diff --git a/src/wayland/meta-wayland-surface.c b/src/wayland/meta-wayland-surface.c
index 2d806b7..e5960bd 100644
--- a/src/wayland/meta-wayland-surface.c
+++ b/src/wayland/meta-wayland-surface.c
@@ -63,6 +63,27 @@ typedef struct
   struct wl_listener sibling_destroy_listener;
 } MetaWaylandSubsurfacePlacementOp;
 
+int
+meta_wayland_surface_set_role (MetaWaylandSurface    *surface,
+                               MetaWaylandSurfaceRole role,
+                               struct wl_resource    *error_resource,
+                               uint32_t               error_code)
+{
+  if (surface->role == META_WAYLAND_SURFACE_ROLE_NONE ||
+      surface->role == role)
+    {
+      surface->role = role;
+      return 0;
+    }
+  else
+    {
+      wl_resource_post_error (error_resource, error_code,
+                              "wl_surface %d already has a different role",
+                              wl_resource_get_id (surface->resource));
+      return -1;
+    }
+}
+
 static void
 surface_set_buffer (MetaWaylandSurface *surface,
                     MetaWaylandBuffer  *buffer)
@@ -979,6 +1000,12 @@ xdg_shell_get_xdg_surface (struct wl_client *client,
       return;
     }
 
+  if (meta_wayland_surface_set_role (surface,
+                                     META_WAYLAND_SURFACE_ROLE_XDG_SURFACE,
+                                     surface_resource,
+                                     XDG_SHELL_ERROR_ROLE) != 0)
+    return;
+
   surface->xdg_surface = wl_resource_create (client, &xdg_surface_interface, wl_resource_get_version 
(resource), id);
   wl_resource_set_implementation (surface->xdg_surface, &meta_wayland_xdg_surface_interface, surface, 
xdg_surface_destructor);
 
@@ -1036,6 +1063,12 @@ xdg_shell_get_xdg_popup (struct wl_client *client,
       return;
     }
 
+  if (meta_wayland_surface_set_role (surface,
+                                     META_WAYLAND_SURFACE_ROLE_XDG_POPUP,
+                                     surface_resource,
+                                     XDG_SHELL_ERROR_ROLE) != 0)
+    return;
+
   surface->xdg_popup = wl_resource_create (client, &xdg_popup_interface, wl_resource_get_version (resource), 
id);
   wl_resource_set_implementation (surface->xdg_popup, &meta_wayland_xdg_popup_interface, surface, 
xdg_popup_destructor);
 
@@ -1303,6 +1336,12 @@ wl_shell_get_shell_surface (struct wl_client *client,
       return;
     }
 
+  if (meta_wayland_surface_set_role (surface,
+                                     META_WAYLAND_SURFACE_ROLE_WL_SHELL_SURFACE,
+                                     surface_resource,
+                                     WL_SHELL_ERROR_ROLE) != 0)
+    return;
+
   surface->wl_shell_surface = wl_resource_create (client, &wl_shell_surface_interface, 
wl_resource_get_version (resource), id);
   wl_resource_set_implementation (surface->wl_shell_surface, &meta_wayland_wl_shell_surface_interface, 
surface, wl_shell_surface_destructor);
 
@@ -1656,6 +1695,12 @@ wl_subcompositor_get_subsurface (struct wl_client *client,
       return;
     }
 
+  if (meta_wayland_surface_set_role (surface,
+                                     META_WAYLAND_SURFACE_ROLE_SUBSURFACE,
+                                     surface_resource,
+                                     WL_SHELL_ERROR_ROLE) != 0)
+    return;
+
   surface->wl_subsurface = wl_resource_create (client, &wl_subsurface_interface, wl_resource_get_version 
(resource), id);
   wl_resource_set_implementation (surface->wl_subsurface, &meta_wayland_wl_subsurface_interface, surface, 
wl_subsurface_destructor);
 
diff --git a/src/wayland/meta-wayland-surface.h b/src/wayland/meta-wayland-surface.h
index 6288d67..dd8497a 100644
--- a/src/wayland/meta-wayland-surface.h
+++ b/src/wayland/meta-wayland-surface.h
@@ -36,6 +36,17 @@ struct _MetaWaylandSerial {
   uint32_t value;
 };
 
+typedef enum
+{
+  META_WAYLAND_SURFACE_ROLE_NONE,
+  META_WAYLAND_SURFACE_ROLE_SUBSURFACE,
+  META_WAYLAND_SURFACE_ROLE_XDG_SURFACE,
+  META_WAYLAND_SURFACE_ROLE_XDG_POPUP,
+  META_WAYLAND_SURFACE_ROLE_WL_SHELL_SURFACE,
+  META_WAYLAND_SURFACE_ROLE_CURSOR,
+  META_WAYLAND_SURFACE_ROLE_DND,
+} MetaWaylandSurfaceRole;
+
 typedef struct
 {
   /* wl_surface.attach */
@@ -66,6 +77,7 @@ struct _MetaWaylandSurface
   struct wl_resource *resource;
   MetaWaylandCompositor *compositor;
   MetaSurfaceActor *surface_actor;
+  MetaWaylandSurfaceRole role;
   MetaWindow *window;
   MetaWaylandBuffer *buffer;
   struct wl_listener buffer_destroy_listener;
@@ -118,6 +130,11 @@ MetaWaylandSurface *meta_wayland_surface_create (MetaWaylandCompositor *composit
                                                  struct wl_resource    *compositor_resource,
                                                  guint32                id);
 
+int                meta_wayland_surface_set_role (MetaWaylandSurface    *surface,
+                                                  MetaWaylandSurfaceRole role,
+                                                  struct wl_resource    *error_resource,
+                                                  uint32_t               error_code);
+
 void                meta_wayland_surface_set_window (MetaWaylandSurface *surface,
                                                      MetaWindow         *window);