wl: Prefer SSD via zxdg_decoration_manager_v1

platform/wayland/cog-platform-wl.c

@@ -212,6 +212,10 @@ registry_on_global(void *data, struct wl_registry *registry, uint32_t name, cons
     } else if (strcmp(interface, weston_content_protection_interface.name) == 0) {
         display->protection = wl_registry_bind(registry, name, &weston_content_protection_interface, 1);
 #endif /* COG_ENABLE_WESTON_CONTENT_PROTECTION */
+#if COG_HAVE_XDG_DECORATION_UNSTABLE_V1
+    } else if (strcmp(interface, zxdg_decoration_manager_v1_interface.name) == 0) {
+        display->xdg_decoration = wl_registry_bind(registry, name, &zxdg_decoration_manager_v1_interface, 1);
+#endif /* COG_HAVE_XDG_DECORATION_UNSTABLE_V1 */
     } else if (strcmp(interface, wl_output_interface.name) == 0) {
         /* Version 2 introduced the wl_output_listener::scale. */
         CogWlOutput *item = g_new0(CogWlOutput, 1);
@@ -1181,6 +1185,10 @@ init_wayland(CogWlPlatform *platform, GError **error)
 static void
 clear_wayland(CogWlPlatform *platform)
 {
+#if COG_HAVE_XDG_DECORATION_UNSTABLE_V1
+    g_clear_pointer(&platform->display->xdg_decoration, zxdg_decoration_manager_v1_destroy);
+#endif /* COG_HAVE_XDG_DECORATION_UNSTABLE_V1 */
+
     cog_wl_display_destroy(platform->display);
 }
 

platform/wayland/cog-utils-wl.h

@@ -15,6 +15,10 @@
 #    include "cog-xdp-parent-wl.h"
 #endif
 
+#if COG_HAVE_XDG_DECORATION_UNSTABLE_V1
+#    include "xdg-decoration-unstable-v1-client.h"
+#endif
+
 #include <wayland-server.h>
 #include <wayland-util.h>
 #include <xkbcommon/xkbcommon.h>
@@ -116,6 +120,10 @@ struct _CogWlWindow {
     struct xdg_toplevel     *xdg_toplevel;
     struct wl_shell_surface *shell_surface;
 
+#if COG_HAVE_XDG_DECORATION_UNSTABLE_V1
+    struct zxdg_toplevel_decoration_v1 *xdg_decoration;
+#endif /* COG_HAVE_XDG_DECORATION_UNSTABLE_V1 */
+
 #if COG_HAVE_LIBPORTAL
     struct xdp_parent_wl_data xdp_parent_wl_data;
 #endif /* COG_HAVE_LIBPORTAL */
@@ -231,6 +239,10 @@ struct _CogWlDisplay {
     struct zwp_fullscreen_shell_v1 *fshell;
     struct wl_shell                *shell;
 
+#if COG_HAVE_XDG_DECORATION_UNSTABLE_V1
+    struct zxdg_decoration_manager_v1 *xdg_decoration;
+#endif
+
     CogWlSeat     *seat_default;
     struct wl_list seats; /* wl_list<CogWlSeat> */
 

platform/wayland/cog-viewport-wl.c

@@ -16,6 +16,10 @@
 #include "fullscreen-shell-unstable-v1-client.h"
 #include "xdg-shell-client.h"
 
+#if COG_HAVE_XDG_DECORATION_UNSTABLE_V1
+#    include "xdg-decoration-unstable-v1-client.h"
+#endif
+
 G_DEFINE_DYNAMIC_TYPE(CogWlViewport, cog_wl_viewport, COG_TYPE_VIEWPORT)
 
 static void cog_wl_viewport_dispose(GObject *);
@@ -41,6 +45,10 @@ destroy_video_surface(gpointer data)
 static void
 destroy_window(CogWlViewport *viewport)
 {
+#if COG_HAVE_XDG_DECORATION_UNSTABLE_V1
+    g_clear_pointer(&viewport->window.xdg_decoration, zxdg_toplevel_decoration_v1_destroy);
+#endif
+
     g_clear_pointer(&viewport->window.xdg_toplevel, xdg_toplevel_destroy);
     g_clear_pointer(&viewport->window.xdg_surface, xdg_surface_destroy);
     g_clear_pointer(&viewport->window.shell_surface, wl_shell_surface_destroy);
@@ -265,6 +273,19 @@ cog_wl_viewport_create_window(CogWlViewport *viewport, GError **error)
         viewport->window.xdg_toplevel = xdg_surface_get_toplevel(viewport->window.xdg_surface);
         g_assert(viewport->window.xdg_toplevel);
 
+#if COG_HAVE_XDG_DECORATION_UNSTABLE_V1
+        /*
+         * Ask the compositor for server-side decorations. The compositor may
+         * still prefer client-side decorations, but do not attach a listener
+         * because knowing the compositor's preference is pointless because
+         * there is no support for painting client-side decorations.
+         */
+        viewport->window.xdg_decoration =
+            zxdg_decoration_manager_v1_get_toplevel_decoration(display->xdg_decoration, viewport->window.xdg_toplevel);
+        zxdg_toplevel_decoration_v1_set_mode(viewport->window.xdg_decoration,
+                                             ZXDG_TOPLEVEL_DECORATION_V1_MODE_SERVER_SIDE);
+#endif /* COG_HAVE_XDG_DECORATION_UNSTABLE_V1 */
+
         xdg_toplevel_add_listener(viewport->window.xdg_toplevel, &xdg_toplevel_listener, viewport);
         xdg_toplevel_set_title(viewport->window.xdg_toplevel, COG_DEFAULT_APPNAME);
 

platform/wayland/meson.build

@@ -38,6 +38,7 @@ wayland_platform_protocols = {
         ['text-input', 1],
         ['text-input', 3],
         ['xdg-foreign', 2],
+        ['xdg-decoration', 1, 'optional'],
     ],
     'weston': wayland_platform_weston_protocols,
 }
@@ -78,22 +79,34 @@ fs = import('fs')
 wayland_platform_sources = []
 foreach kind, proto_list : wayland_platform_protocols
     foreach item : proto_list
+        proto_optional = false
         if kind == 'stable'
             proto_name = item
             proto_dir = join_paths(wayland_protocols_path, 'stable', item)
         elif kind == 'unstable' or kind == 'staging'
             proto_name = '@0@-@1@-v@2@'.format(item[0], kind, item[1])
             proto_dir = join_paths(wayland_protocols_path, 'unstable', item[0])
+            proto_optional = item.length() == 3 and item[2] == 'optional'
         elif kind == 'weston'
             proto_name = item
             proto_dir = weston_protocols_path
         else
             error('Unknown Wayland protocol type: @0@'.format(kind))
         endif
+        proto_macro = proto_name.underscorify().to_upper()
 
         xml_path = join_paths(proto_dir, '@[email protected]'.format(proto_name))
         if not fs.is_file(xml_path)
-            error('Cannot find protocol @0@, file does not exist: @1@'.format(proto_name, xml_path))
+            if proto_optional
+                wayland_platform_c_args += ['-DHAVE_@0@=0'.format(proto_macro)]
+                continue
+            else
+                error('Cannot find protocol @0@, file does not exist: @1@'.format(proto_name, xml_path))
+            endif
+        endif
+
+        if proto_optional
+            wayland_platform_c_args += ['-DCOG_HAVE_@0@=1'.format(proto_macro)]
         endif
 
         wayland_platform_sources += [custom_target(