[gtk+] wayland: Place subsurfaces relative to their parent

[Olivier Fourdan <ofourdan src gnome org>]

commit 39200e75b6364f50acebf032d4aa1455a2bf0628
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Wed Nov 23 14:55:40 2016 +0100

    wayland: Place subsurfaces relative to their parent
    
    Now that subsurfaces can be created as child of another GdkWindow (and
    not just the root window), they must be placed according to the location
    of their parent, i.e. the abs_x/abs_y must be updated and taken int
    account when placing and moving subsurfaces under Wayland.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=774917

 gdk/gdkwindow.c                 |    7 +++++--
 gdk/wayland/gdkwindow-wayland.c |    8 ++++++--
 2 files changed, 11 insertions(+), 4 deletions(-)
---
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index 3f2d526..83002b7 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -796,9 +796,12 @@ recompute_visible_regions_internal (GdkWindow *private,
   old_abs_y = private->abs_y;
 
   /* Update absolute position */
-  if (gdk_window_has_impl (private))
+  if ((gdk_window_has_impl (private) &&
+       private->window_type != GDK_WINDOW_SUBSURFACE) ||
+      (gdk_window_is_toplevel (private) &&
+       private->window_type == GDK_WINDOW_SUBSURFACE))
     {
-      /* Native window starts here */
+      /* Native windows and toplevel subsurfaces start here */
       private->abs_x = 0;
       private->abs_y = 0;
     }
diff --git a/gdk/wayland/gdkwindow-wayland.c b/gdk/wayland/gdkwindow-wayland.c
index 12ce613..5360c4b 100644
--- a/gdk/wayland/gdkwindow-wayland.c
+++ b/gdk/wayland/gdkwindow-wayland.c
@@ -1263,7 +1263,9 @@ gdk_wayland_window_create_subsurface (GdkWindow *window)
       impl->display_server.wl_subsurface =
         wl_subcompositor_get_subsurface (display_wayland->subcompositor,
                                          impl->display_server.wl_surface, 
parent_impl->display_server.wl_surface);
-      wl_subsurface_set_position (impl->display_server.wl_subsurface, window->x, window->y);
+      wl_subsurface_set_position (impl->display_server.wl_subsurface,
+                                  window->x + window->abs_x,
+                                  window->y + window->abs_y);
 
       /* In order to synchronize the initial position with the initial frame
        * content, wait with making the subsurface desynchronized until after
@@ -2592,7 +2594,9 @@ gdk_window_wayland_move_resize (GdkWindow *window,
 
           if (impl->display_server.wl_subsurface)
             {
-              wl_subsurface_set_position (impl->display_server.wl_subsurface, x, y);
+              wl_subsurface_set_position (impl->display_server.wl_subsurface,
+                                          window->x + window->abs_x,
+                                          window->y + window->abs_y);
               gdk_window_request_transient_parent_commit (window);
             }
         }