fullscreen-shell: Link with shell-utils helpers

Unlike desktop-shell and kiosk-shell, the fullscreen-shell does not link
with the common shell-utils helpers. This is largely because
fullscreen-shell is largely in 'maintenance mode', seeing little more
than occasional bug fixes or changes required to accommodate new
interfaces.

This commit adds a dependency from fullscreen-shell to use the
shell-utils helper, in order to allow fullscreen-shell to use the new
weston_curtain infrastructure, rather than continuing to open-code the
common pattern of creating a surface and view consisting only of a solid
colour for the background of fullscreen surfaces which do not wholly
cover the output.

In doing this, the 'surface_subsurfaces_boundingbox()' function is
removed, as this has been duplicated between the fullscreen-shell and
the common helper 'library'.

There is no functional change within this commit, as the two functions
were identical, other than a change to the comment which identifies a
known bug within this helper.

Signed-off-by: Daniel Stone <daniels@collabora.com>

fullscreen-shell/fullscreen-shell.c

@@ -37,6 +37,7 @@
 #include "compositor/weston.h"
 #include "fullscreen-shell-unstable-v1-server-protocol.h"
 #include "shared/helpers.h"
+#include "shell-utils.h"
 
 struct fullscreen_shell {
 	struct wl_client *client;
@@ -373,41 +374,6 @@ restore_output_mode(struct weston_output *output)
 		weston_output_mode_switch_to_native(output);
 }
 
-/*
- * Returns the bounding box of a surface and all its sub-surfaces,
- * in surface-local coordinates. */
-static void
-surface_subsurfaces_boundingbox(struct weston_surface *surface, int32_t *x,
-				int32_t *y, int32_t *w, int32_t *h) {
-	pixman_region32_t region;
-	pixman_box32_t *box;
-	struct weston_subsurface *subsurface;
-
-	pixman_region32_init_rect(&region, 0, 0,
-	                          surface->width,
-	                          surface->height);
-
-	wl_list_for_each(subsurface, &surface->subsurface_list, parent_link) {
-		pixman_region32_union_rect(&region, &region,
-		                           subsurface->position.x,
-		                           subsurface->position.y,
-		                           subsurface->surface->width,
-		                           subsurface->surface->height);
-	}
-
-	box = pixman_region32_extents(&region);
-	if (x)
-		*x = box->x1;
-	if (y)
-		*y = box->y1;
-	if (w)
-		*w = box->x2 - box->x1;
-	if (h)
-		*h = box->y2 - box->y1;
-
-	pixman_region32_fini(&region);
-}
-
 static void
 fs_output_center_view(struct fs_output *fsout)
 {

fullscreen-shell/meson.build

@@ -4,9 +4,10 @@ if get_option('shell-fullscreen')
 		fullscreen_shell_unstable_v1_server_protocol_h,
 		fullscreen_shell_unstable_v1_protocol_c,
 	]
-	deps_shell_fullscreen=[
+	deps_shell_fullscreen = [
 		dep_libweston_public,
 		dep_libexec_weston,
+		dep_shell_utils,
 	]
 	shared_library(
 		'fullscreen-shell',