info: Get renderer from gnome-session under Wayland

Now that gnome-session's acceleration helper can print the renderer
under Wayland, launch it locally. We need to launch it locally as
Wayland is not available at the time gnome-session would launch the
helper, as there's no Wayland compositor yet.

Note that this code expects the gnome-session helper scripts to live
in $libexecdir, but distributions can use
--with-gnome-session-libexecdir=DIR to pass another one.

https://bugzilla.gnome.org/show_bug.cgi?id=756914

configure.ac

@@ -340,6 +340,17 @@ AC_SUBST(KRB5_LIBS)
 USER_ACCOUNTS_PANEL_CFLAGS="$USER_ACCOUNTS_PANEL_CFLAGS $KRB5_CFLAGS"
 USER_ACCOUNTS_PANEL_LIBS="$USER_ACCOUNTS_PANEL_LIBS $KRB5_LIBS"
 
+dnl Check for info panel
+AC_ARG_WITH([gnome-session-libexecdir],
+	    AS_HELP_STRING([--with-gnome-session-libexecdir=DIR], [Directory for gnome-session s libexecdir]),
+	    [],
+	    [with_gnome_session_libexecdir=${libexecdir}])
+if test x$with_gnome_session_libexecdir == xno; then
+	with_gnome_session_libexecdir=${libexecdir}
+fi
+AS_AC_EXPAND(GNOMESESSIONDIR, $with_gnome_session_libexecdir)
+AC_SUBST([gnome_session_libexecdir], [$GNOMESESSIONDIR])
+
 dnl =======================================
 dnl Panels
 dnl =======================================
@@ -589,4 +600,5 @@ if test "x$enable_ibus" = "xyes"; then
 else
 	AC_MSG_NOTICE([   Region panel IBus support disabled])
 fi
+AC_MSG_NOTICE([** gnome-session libexecdir: $GNOMESESSIONDIR])
 AC_MSG_NOTICE([End options])

m4/as-ac-expand.m4

@@ -0,0 +1,43 @@
+dnl as-ac-expand.m4 0.2.0
+dnl autostars m4 macro for expanding directories using configure's prefix
+dnl thomas@apestaart.org
+
+dnl AS_AC_EXPAND(VAR, CONFIGURE_VAR)
+dnl example
+dnl AS_AC_EXPAND(SYSCONFDIR, $sysconfdir)
+dnl will set SYSCONFDIR to /usr/local/etc if prefix=/usr/local
+
+AC_DEFUN([AS_AC_EXPAND],
+[
+  EXP_VAR=[$1]
+  FROM_VAR=[$2]
+
+  dnl first expand prefix and exec_prefix if necessary
+  prefix_save=$prefix
+  exec_prefix_save=$exec_prefix
+
+  dnl if no prefix given, then use /usr/local, the default prefix
+  if test "x$prefix" = "xNONE"; then
+    prefix="$ac_default_prefix"
+  fi
+  dnl if no exec_prefix given, then use prefix
+  if test "x$exec_prefix" = "xNONE"; then
+    exec_prefix=$prefix
+  fi
+
+  full_var="$FROM_VAR"
+  dnl loop until it doesn't change anymore
+  while true; do
+    new_full_var="`eval echo $full_var`"
+    if test "x$new_full_var" = "x$full_var"; then break; fi
+    full_var=$new_full_var
+  done
+
+  dnl clean up
+  full_var=$new_full_var
+  AC_SUBST([$1], "$full_var")
+
+  dnl restore prefix and exec_prefix
+  prefix=$prefix_save
+  exec_prefix=$exec_prefix_save
+])

panels/info/Makefile.am

@@ -1,11 +1,12 @@
 cappletname = info
 
-AM_CPPFLAGS = 						\
-	$(PANEL_CFLAGS)					\
-	$(INFO_PANEL_CFLAGS)				\
-	-DGNOMELOCALEDIR="\"$(datadir)/locale\""	\
-	-DDATADIR="\"$(datadir)\""			\
-	-DBINDIR="\"$(bindir)\""			\
+AM_CPPFLAGS =							\
+	$(PANEL_CFLAGS)						\
+	$(INFO_PANEL_CFLAGS)					\
+	-DGNOMELOCALEDIR="\"$(datadir)/locale\""		\
+	-DDATADIR="\"$(datadir)\""				\
+	-DGNOME_SESSION_DIR="\"$(gnome_session_libexecdir)\""	\
+	-DBINDIR="\"$(bindir)\""				\
 	$(NULL)
 
 noinst_LTLIBRARIES = libinfo.la

panels/info/cc-info-panel.c

@@ -235,6 +235,9 @@ prettify_info (const char *info)
     { "Graphics Controller", "Graphics"},
   };
 
+  if (*info == '\0')
+    return NULL;
+
   pretty = g_markup_escape_text (info, -1);
 
   for (i = 0; i < G_N_ELEMENTS (rs); i++)
@@ -322,6 +325,27 @@ get_renderer_from_session (void)
   return renderer;
 }
 
+static char *
+get_renderer_from_helper (void)
+{
+  int status;
+  char *argv[] = { GNOME_SESSION_DIR "/gnome-session-check-accelerated", NULL };
+  char *renderer, *ret;
+
+  if (!g_spawn_sync (NULL, (char **) argv, NULL, 0, NULL, NULL, &renderer, NULL, &status, NULL))
+    return NULL;
+
+  if (!g_spawn_check_exit_status (status, NULL))
+    return NULL;
+
+  if (renderer == NULL || *renderer == '\0')
+    return NULL;
+
+  ret = prettify_info (renderer);
+  g_free (renderer);
+  return ret;
+}
+
 static GraphicsData *
 get_graphics_data (void)
 {
@@ -332,19 +356,18 @@ get_graphics_data (void)
 
   display = gdk_display_get_default ();
 
-#ifdef GDK_WINDOWING_X11
-  if (GDK_IS_X11_DISPLAY (display))
+#if defined(GDK_WINDOWING_X11) || defined(GDK_WINDOWING_WAYLAND)
+  if (GDK_IS_X11_DISPLAY (display) ||
+      GDK_IS_WAYLAND_DISPLAY (display))
     {
       result->renderer = get_renderer_from_session ();
+      if (!result->renderer)
+        result->renderer = get_renderer_from_helper ();
       result->hardware_string = result->renderer;
     }
-  else
-#endif
-#ifdef GDK_WINDOWING_WAYLAND
-  if (GDK_IS_WAYLAND_DISPLAY (display))
-    result->hardware_string = _("Wayland");
-  else
 #endif
+
+  if (!result->renderer)
     result->hardware_string = _("Unknown");
 
   return result;